diff --git a/.github/ISSUE_TEMPLATE/config.yml b/.github/ISSUE_TEMPLATE/config.yml
index 3e62958d8..d8c6d66ca 100644
--- a/.github/ISSUE_TEMPLATE/config.yml
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -1,8 +1,15 @@
 blank_issues_enabled: true
 contact_links:
-  - name: Gitter channel (actix-web)
+  - name: GitHub Discussions
+    url: https://github.com/actix/actix-web/discussions
+    about: Actix Web Q&A
+  - name: Gitter chat (actix-web)
     url: https://gitter.im/actix/actix-web
-    about: Please ask and answer questions about the actix-web here.
-  - name: Gitter channel (actix)
+    about: Actix Web Q&A
+  - name: Gitter chat (actix)
     url: https://gitter.im/actix/actix
-    about: Please ask and answer questions about the actix here.
+    about: Actix (actor framework) Q&A
+  - name: Actix Discord
+    url: https://discord.gg/NWpN5mmg3x
+    about: Actix developer discussion and community chat
+
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index b779b33fa..42deadf5a 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -1,21 +1,21 @@
 <!-- Thanks for considering contributing actix! -->
-<!-- Please fill out the following to make our reviews easy. -->
+<!-- Please fill out the following to get your PR reviewed quicker. -->
 
 ## PR Type
 <!-- What kind of change does this PR make? -->
 <!-- Bug Fix / Feature / Refactor / Code Style / Other -->
-INSERT_PR_TYPE
+PR_TYPE
 
 
 ## PR Checklist
-Check your PR fulfills the following:
-
+<!-- Check your PR fulfills the following items. ->>
 <!-- For draft PRs check the boxes as you complete them. -->
 
 - [ ] Tests for the changes have been added / updated.
 - [ ] Documentation comments have been added / updated.
 - [ ] A changelog entry has been made for the appropriate packages.
-- [ ] Format code with the latest stable rustfmt
+- [ ] Format code with the latest stable rustfmt.
+- [ ] (Team) Label with affected crates and semver status.
 
 
 ## Overview
diff --git a/.github/workflows/bench.yml b/.github/workflows/bench.yml
index d19471a16..828d62561 100644
--- a/.github/workflows/bench.yml
+++ b/.github/workflows/bench.yml
@@ -1,4 +1,4 @@
-name: Benchmark (Linux)
+name: Benchmark
 
 on:
   pull_request:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 000000000..7d0520d52
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,103 @@
+name: CI
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+  push:
+    branches: [master]
+
+jobs:
+  build_and_test:
+    strategy:
+      fail-fast: false
+      matrix:
+        target:
+          - { name: Linux, os: ubuntu-latest, triple: x86_64-unknown-linux-gnu }
+          - { name: macOS, os: macos-latest, triple: x86_64-apple-darwin }
+          - { name: Windows, os: windows-latest, triple: x86_64-pc-windows-msvc }
+        version:
+          - 1.46.0 # MSRV
+          - stable
+          - nightly
+
+    name: ${{ matrix.target.name }} / ${{ matrix.version }}
+    runs-on: ${{ matrix.target.os }}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install ${{ matrix.version }}
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.version }}-${{ matrix.target.triple }}
+          profile: minimal
+          override: true
+
+      - name: Generate Cargo.lock
+        uses: actions-rs/cargo@v1
+        with:
+          command: generate-lockfile
+      - name: Cache Dependencies
+        uses: Swatinem/rust-cache@v1.2.0
+
+      - name: Install cargo-hack
+        uses: actions-rs/cargo@v1
+        with:
+          command: install
+          args: cargo-hack
+
+      - name: check minimal
+        uses: actions-rs/cargo@v1
+        with:
+          command: hack
+          args: --clean-per-run check --workspace --no-default-features --tests
+
+      - name: check full
+        uses: actions-rs/cargo@v1
+        with:
+          command: check
+          args: --workspace --bins --examples --tests
+
+      - name: tests
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: -v --workspace --all-features --no-fail-fast -- --nocapture
+            --skip=test_h2_content_length
+            --skip=test_reading_deflate_encoding_large_random_rustls
+
+      - name: tests (actix-http)
+        uses: actions-rs/cargo@v1
+        timeout-minutes: 40
+        with:
+          command: test
+          args: --package=actix-http --no-default-features --features=rustls -- --nocapture
+
+      - name: tests (awc)
+        uses: actions-rs/cargo@v1
+        timeout-minutes: 40
+        with:
+          command: test
+          args: --package=awc --no-default-features --features=rustls -- --nocapture
+
+      - name: Generate coverage file
+        if: >
+          matrix.target.os == 'ubuntu-latest'
+          && matrix.version == 'stable'
+          && github.ref == 'refs/heads/master'
+        run: |
+          cargo install cargo-tarpaulin --vers "^0.13"
+          cargo tarpaulin --out Xml --verbose
+      - name: Upload to Codecov
+        if: >
+          matrix.target.os == 'ubuntu-latest'
+          && matrix.version == 'stable'
+          && github.ref == 'refs/heads/master'
+        uses: codecov/codecov-action@v1
+        with:
+          file: cobertura.xml
+
+      - name: Clear the cargo caches
+        run: |
+          cargo install cargo-cache --no-default-features --features ci-autoclean
+          cargo-cache
diff --git a/.github/workflows/clippy-fmt.yml b/.github/workflows/clippy-fmt.yml
index fb1ed7f32..e966fa4ab 100644
--- a/.github/workflows/clippy-fmt.yml
+++ b/.github/workflows/clippy-fmt.yml
@@ -1,32 +1,39 @@
+name: Lint
+
 on:
   pull_request:
     types: [opened, synchronize, reopened]
 
-name: Clippy and rustfmt Check
 jobs:
-  clippy_check:
+  fmt:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
 
-      - uses: actions-rs/toolchain@v1
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
           components: rustfmt
-          override: true
       - name: Check with rustfmt
         uses: actions-rs/cargo@v1
         with:
           command: fmt
           args: --all -- --check
 
-      - uses: actions-rs/toolchain@v1
+  clippy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
         with:
-          toolchain: nightly
+          toolchain: stable
           components: clippy
           override: true
       - name: Check with Clippy
         uses: actions-rs/clippy-check@v1
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
-          args: --all-features --all --tests
+          args: --workspace --tests --all-features
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
deleted file mode 100644
index a068070ff..000000000
--- a/.github/workflows/linux.yml
+++ /dev/null
@@ -1,69 +0,0 @@
-name: CI (Linux)
-
-on:
-  pull_request:
-    types: [opened, synchronize, reopened]
-  push:
-    branches:
-      - master
-
-jobs:
-  build_and_test:
-    strategy:
-      fail-fast: false
-      matrix:
-        version:
-          - 1.42.0 # MSRV
-          - stable
-          - nightly
-
-    name: ${{ matrix.version }} - x86_64-unknown-linux-gnu
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v2
-
-      - name: Install ${{ matrix.version }}
-        uses: actions-rs/toolchain@v1
-        with:
-          toolchain: ${{ matrix.version }}-x86_64-unknown-linux-gnu
-          profile: minimal
-          override: true
-
-      - name: check build
-        uses: actions-rs/cargo@v1
-        with:
-          command: check
-          args: --all --bins --examples --tests
-
-      - name: tests
-        uses: actions-rs/cargo@v1
-        timeout-minutes: 40
-        with:
-          command: test
-          args: --all --all-features --no-fail-fast -- --nocapture
-
-      - name: tests (actix-http)
-        uses: actions-rs/cargo@v1
-        timeout-minutes: 40
-        with:
-          command: test
-          args: --package=actix-http --no-default-features --features=rustls -- --nocapture
-
-      - name: tests (awc)
-        uses: actions-rs/cargo@v1
-        timeout-minutes: 40
-        with:
-          command: test
-          args: --package=awc --no-default-features --features=rustls -- --nocapture
-
-      - name: Generate coverage file
-        if: matrix.version == 'stable' && (github.ref == 'refs/heads/master' || github.event_name == 'pull_request')
-        run: |
-          cargo install cargo-tarpaulin --vers "^0.13"
-          cargo tarpaulin --out Xml
-      - name: Upload to Codecov
-        if: matrix.version == 'stable' && (github.ref == 'refs/heads/master' || github.event_name == 'pull_request')
-        uses: codecov/codecov-action@v1
-        with:
-          file: cobertura.xml
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
deleted file mode 100644
index dc8558ac1..000000000
--- a/.github/workflows/macos.yml
+++ /dev/null
@@ -1,44 +0,0 @@
-name: CI (macOS)
-
-on:
-  pull_request:
-    types: [opened, synchronize, reopened]
-  push:
-    branches:
-      - master
-
-jobs:
-  build_and_test:
-    strategy:
-      fail-fast: false
-      matrix:
-        version:
-          - stable
-          - nightly
-
-    name: ${{ matrix.version }} - x86_64-apple-darwin
-    runs-on: macOS-latest
-
-    steps:
-      - uses: actions/checkout@v2
-
-      - name: Install ${{ matrix.version }}
-        uses: actions-rs/toolchain@v1
-        with:
-          toolchain: ${{ matrix.version }}-x86_64-apple-darwin
-          profile: minimal
-          override: true
-
-      - name: check build
-        uses: actions-rs/cargo@v1
-        with:
-          command: check
-          args: --all --bins --examples --tests
-
-      - name: tests
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --all --all-features --no-fail-fast -- --nocapture
-                --skip=test_h2_content_length
-                --skip=test_reading_deflate_encoding_large_random_rustls
diff --git a/.github/workflows/upload-doc.yml b/.github/workflows/upload-doc.yml
index 99fa663cc..c080dd8c3 100644
--- a/.github/workflows/upload-doc.yml
+++ b/.github/workflows/upload-doc.yml
@@ -16,7 +16,7 @@ jobs:
       - name: Install Rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable-x86_64-unknown-linux-gnu
+          toolchain: nightly-x86_64-unknown-linux-gnu
           profile: minimal
           override: true
 
@@ -24,13 +24,13 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: doc
-          args: --no-deps --workspace --all-features
+          args: --workspace --all-features --no-deps
 
       - name: Tweak HTML
         run: echo "<meta http-equiv=refresh content=0;url=os_balloon/index.html>" > target/doc/index.html
 
       - name: Deploy to GitHub Pages
-        uses: JamesIves/github-pages-deploy-action@3.5.8
+        uses: JamesIves/github-pages-deploy-action@3.7.1
         with:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           BRANCH: gh-pages
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
deleted file mode 100644
index d53d50a61..000000000
--- a/.github/workflows/windows.yml
+++ /dev/null
@@ -1,64 +0,0 @@
-name: CI (Windows)
-
-on:
-  pull_request:
-    types: [opened, synchronize, reopened]
-  push:
-    branches:
-      - master
-
-env:
-  VCPKGRS_DYNAMIC: 1
-
-jobs:
-  build_and_test:
-    strategy:
-      fail-fast: false
-      matrix:
-        version:
-          - stable
-          - nightly
-
-    name: ${{ matrix.version }} - x86_64-pc-windows-msvc
-    runs-on: windows-latest
-
-    steps:
-      - uses: actions/checkout@v2
-
-      - name: Install ${{ matrix.version }}
-        uses: actions-rs/toolchain@v1
-        with:
-          toolchain: ${{ matrix.version }}-x86_64-pc-windows-msvc
-          profile: minimal
-          override: true
-
-      - name: Install OpenSSL
-        run: |
-          vcpkg integrate install
-          vcpkg install openssl:x64-windows
-          Copy-Item C:\vcpkg\installed\x64-windows\bin\libcrypto-1_1-x64.dll C:\vcpkg\installed\x64-windows\bin\libcrypto.dll
-          Copy-Item C:\vcpkg\installed\x64-windows\bin\libssl-1_1-x64.dll C:\vcpkg\installed\x64-windows\bin\libssl.dll
-          Get-ChildItem C:\vcpkg\installed\x64-windows\bin
-          Get-ChildItem C:\vcpkg\installed\x64-windows\lib
-
-      - name: check build
-        uses: actions-rs/cargo@v1
-        with:
-          command: check
-          args: --all --bins --examples --tests
-
-      - name: tests
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --all --all-features --no-fail-fast -- --nocapture
-                --skip=test_h2_content_length
-                --skip=test_reading_deflate_encoding_large_random_rustls
-                --skip=test_params
-                --skip=test_simple
-                --skip=test_expect_continue
-                --skip=test_http10_keepalive
-                --skip=test_slow_request
-                --skip=test_connection_force_close
-                --skip=test_connection_server_close
-                --skip=test_connection_wait_queue_force_close
diff --git a/CHANGES.md b/CHANGES.md
index 86e022409..7cb03c30c 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,13 +1,152 @@
 # Changes
 
-## Unreleased - 2020-xx-xx
+## Unreleased - 2021-xx-xx
 ### Changed
-* Add `TrailingSlash::MergeOnly` behaviour to `NormalizePath`, which allow `NormalizePath`
-  to keep the trailing slash's existance as it is. [#1695]
-* Fix `ResourceMap` recursive references when printing/debugging. [#1708]
-* Remove bound `std::marker::Sized` from `web::Data` to support storing `Arc<dyn Trait>` via `web::Data::from` [#1710]
+* Feature `cookies` is now optional and enabled by default. [#1981]
+* `JsonBody::new` returns a default limit of 32kB to be consistent with `JsonConfig` and the
+  default behaviour of the `web::Json<T>` extractor. [#2010] 
 
+[#1981]: https://github.com/actix/actix-web/pull/1981
+[#2010]: https://github.com/actix/actix-web/pull/2010
+
+
+## 4.0.0-beta.3 - 2021-02-10
+* Update `actix-web-codegen` to `0.5.0-beta.1`.
+
+
+## 4.0.0-beta.2 - 2021-02-10
+### Added
+* The method `Either<web::Json<T>, web::Form<T>>::into_inner()` which returns the inner type for
+  whichever variant was created. Also works for `Either<web::Form<T>, web::Json<T>>`. [#1894]
+* Add `services!` macro for helping register multiple services to `App`. [#1933]
+* Enable registering a vec of services of the same type to `App` [#1933]
+
+### Changed
+* Rework `Responder` trait to be sync and returns `Response`/`HttpResponse` directly.
+  Making it simpler and more performant. [#1891]
+* `ServiceRequest::into_parts` and `ServiceRequest::from_parts` can no longer fail. [#1893]
+* `ServiceRequest::from_request` can no longer fail. [#1893]
+* Our `Either` type now uses `Left`/`Right` variants (instead of `A`/`B`) [#1894]
+* `test::{call_service, read_response, read_response_json, send_request}` take `&Service`
+  in argument [#1905]
+* `App::wrap_fn`, `Resource::wrap_fn` and `Scope::wrap_fn` provide `&Service` in closure
+  argument. [#1905]
+* `web::block` no longer requires the output is a Result. [#1957]
+
+### Fixed
+* Multiple calls to `App::data` with the same type now keeps the latest call's data. [#1906]
+
+### Removed
+* Public field of `web::Path` has been made private. [#1894]
+* Public field of `web::Query` has been made private. [#1894]
+* `TestRequest::with_header`; use `TestRequest::default().insert_header()`. [#1869]
+* `AppService::set_service_data`; for custom HTTP service factories adding application data, use the
+  layered data model by calling `ServiceRequest::add_data_container` when handling
+  requests instead. [#1906]
+
+[#1891]: https://github.com/actix/actix-web/pull/1891
+[#1893]: https://github.com/actix/actix-web/pull/1893
+[#1894]: https://github.com/actix/actix-web/pull/1894
+[#1869]: https://github.com/actix/actix-web/pull/1869
+[#1905]: https://github.com/actix/actix-web/pull/1905
+[#1906]: https://github.com/actix/actix-web/pull/1906
+[#1933]: https://github.com/actix/actix-web/pull/1933
+[#1957]: https://github.com/actix/actix-web/pull/1957
+
+
+## 4.0.0-beta.1 - 2021-01-07
+### Added
+* `Compat` middleware enabling generic response body/error type of middlewares like `Logger` and
+  `Compress` to be used in `middleware::Condition` and `Resource`, `Scope` services. [#1865]
+
+### Changed
+* Update `actix-*` dependencies to tokio `1.0` based versions. [#1813]
+* Bumped `rand` to `0.8`.
+* Update `rust-tls` to `0.19`. [#1813]
+* Rename `Handler` to `HandlerService` and rename `Factory` to `Handler`. [#1852]
+* The default `TrailingSlash` is now `Trim`, in line with existing documentation. See migration
+  guide for implications. [#1875]
+* Rename `DefaultHeaders::{content_type => add_content_type}`. [#1875]
+* MSRV is now 1.46.0.
+
+### Fixed
+* Added the underlying parse error to `test::read_body_json`'s panic message. [#1812]
+
+### Removed
+* Public modules `middleware::{normalize, err_handlers}`. All necessary middleware structs are now
+  exposed directly by the `middleware` module.
+* Remove `actix-threadpool` as dependency. `actix_threadpool::BlockingError` error type can be imported 
+  from `actix_web::error` module. [#1878]
+
+[#1812]: https://github.com/actix/actix-web/pull/1812
+[#1813]: https://github.com/actix/actix-web/pull/1813
+[#1852]: https://github.com/actix/actix-web/pull/1852
+[#1865]: https://github.com/actix/actix-web/pull/1865
+[#1875]: https://github.com/actix/actix-web/pull/1875
+[#1878]: https://github.com/actix/actix-web/pull/1878
+
+## 3.3.2 - 2020-12-01
+### Fixed
+* Removed an occasional `unwrap` on `None` panic in `NormalizePathNormalization`. [#1762]
+* Fix `match_pattern()` returning `None` for scope with empty path resource. [#1798]
+* Increase minimum `socket2` version. [#1803]
+
+[#1762]: https://github.com/actix/actix-web/pull/1762
+[#1798]: https://github.com/actix/actix-web/pull/1798
+[#1803]: https://github.com/actix/actix-web/pull/1803
+
+
+## 3.3.1 - 2020-11-29
+* Ensure `actix-http` dependency uses same `serde_urlencoded`.
+
+
+## 3.3.0 - 2020-11-25
+### Added
+* Add `Either<A, B>` extractor helper. [#1788]
+
+### Changed
+* Upgrade `serde_urlencoded` to `0.7`. [#1773]
+
+[#1773]: https://github.com/actix/actix-web/pull/1773
+[#1788]: https://github.com/actix/actix-web/pull/1788
+
+
+## 3.2.0 - 2020-10-30
+### Added
+* Implement `exclude_regex` for Logger middleware. [#1723]
+* Add request-local data extractor `web::ReqData`. [#1748]
+* Add ability to register closure for request middleware logging. [#1749]
+* Add `app_data` to `ServiceConfig`. [#1757]
+* Expose `on_connect` for access to the connection stream before request is handled. [#1754]
+
+### Changed
+* Updated actix-web-codegen dependency for access to new `#[route(...)]` multi-method macro.
+* Print non-configured `Data<T>` type when attempting extraction. [#1743]
+* Re-export bytes::Buf{Mut} in web module. [#1750]
+* Upgrade `pin-project` to `1.0`.
+
+[#1723]: https://github.com/actix/actix-web/pull/1723
+[#1743]: https://github.com/actix/actix-web/pull/1743
+[#1748]: https://github.com/actix/actix-web/pull/1748
+[#1750]: https://github.com/actix/actix-web/pull/1750
+[#1754]: https://github.com/actix/actix-web/pull/1754
+[#1749]: https://github.com/actix/actix-web/pull/1749
+
+
+## 3.1.0 - 2020-09-29
+### Changed
+* Add `TrailingSlash::MergeOnly` behaviour to `NormalizePath`, which allows `NormalizePath`
+  to retain any trailing slashes. [#1695]
+* Remove bound `std::marker::Sized` from `web::Data` to support storing `Arc<dyn Trait>`
+  via `web::Data::from` [#1710]
+
+### Fixed
+* `ResourceMap` debug printing is no longer infinitely recursive. [#1708]
+
+[#1695]: https://github.com/actix/actix-web/pull/1695
 [#1708]: https://github.com/actix/actix-web/pull/1708
+[#1710]: https://github.com/actix/actix-web/pull/1710
+
 
 ## 3.0.2 - 2020-09-15
 ### Fixed
@@ -177,7 +316,7 @@
 
 ### Deleted
 
-* Delete HttpServer::run(), it is not useful witht async/await
+* Delete HttpServer::run(), it is not useful with async/await
 
 ## [2.0.0-alpha.3] - 2019-12-07
 
@@ -222,7 +361,7 @@
 
 ### Changed
 
-* Make UrlEncodedError::Overflow more informativve
+* Make UrlEncodedError::Overflow more informative
 
 * Use actix-testing for testing utils
 
@@ -240,7 +379,7 @@
 
 * Re-implement Host predicate (#989)
 
-* Form immplements Responder, returning a `application/x-www-form-urlencoded` response
+* Form implements Responder, returning a `application/x-www-form-urlencoded` response
 
 * Add `into_inner` to `Data`
 
diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md
index 599b28c0d..ae97b3240 100644
--- a/CODE_OF_CONDUCT.md
+++ b/CODE_OF_CONDUCT.md
@@ -34,10 +34,13 @@ This Code of Conduct applies both within project spaces and in public spaces whe
 
 ## Enforcement
 
-Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at fafhrd91@gmail.com. The project team will review and investigate all complaints, and will respond in a way that it deems appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at robjtede@icloud.com ([@robjtede]) or huyuumi@neet.club ([@JohnTitor]). The project team will review and investigate all complaints, and will respond in a way that it deems appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
 
 Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
 
+[@robjtede]: https://github.com/robjtede
+[@JohnTitor]: https://github.com/JohnTitor
+
 ## Attribution
 
 This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [http://contributor-covenant.org/version/1/4][version]
diff --git a/Cargo.toml b/Cargo.toml
index d4da4af11..1a1b8645c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "actix-web"
-version = "3.0.2"
+version = "4.0.0-beta.3"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
-description = "Actix web is a powerful, pragmatic, and extremely fast web framework for Rust."
+description = "Actix Web is a powerful, pragmatic, and extremely fast web framework for Rust"
 readme = "README.md"
 keywords = ["actix", "http", "web", "framework", "async"]
 homepage = "https://actix.rs"
@@ -15,6 +15,7 @@ license = "MIT OR Apache-2.0"
 edition = "2018"
 
 [package.metadata.docs.rs]
+# features that docs.rs will build with
 features = ["openssl", "rustls", "compress", "secure-cookies"]
 
 [badges]
@@ -34,23 +35,26 @@ members = [
   "actix-multipart",
   "actix-web-actors",
   "actix-web-codegen",
-  "test-server",
+  "actix-http-test",
 ]
 
 [features]
-default = ["compress"]
+default = ["compress", "cookies"]
 
 # content-encoding support
 compress = ["actix-http/compress", "awc/compress"]
 
-# sessions feature
+# support for cookies
+cookies = ["actix-http/cookies", "awc/cookies"]
+
+# secure cookies feature
 secure-cookies = ["actix-http/secure-cookies"]
 
 # openssl
-openssl = ["actix-tls/openssl", "awc/openssl", "open-ssl"]
+openssl = ["tls-openssl", "actix-tls/accept", "actix-tls/openssl", "awc/openssl"]
 
 # rustls
-rustls = ["actix-tls/rustls", "awc/rustls", "rust-tls"]
+rustls = ["tls-rustls", "actix-tls/accept", "actix-tls/rustls", "awc/rustls"]
 
 [[example]]
 name = "basic"
@@ -64,52 +68,63 @@ required-features = ["compress"]
 name = "test_server"
 required-features = ["compress"]
 
+[[example]]
+name = "on_connect"
+required-features = []
+
+[[example]]
+name = "client"
+required-features = ["rustls"]
+
 [dependencies]
-actix-codec = "0.3.0"
-actix-service = "1.0.6"
-actix-utils = "2.0.0"
-actix-router = "0.2.4"
-actix-rt = "1.1.1"
-actix-server = "1.0.0"
-actix-testing = "1.0.0"
-actix-macros = "0.1.0"
-actix-threadpool = "0.3.1"
-actix-tls = "2.0.0"
+actix-codec = "0.4.0-beta.1"
+actix-macros = "0.2.0"
+actix-router = "0.2.7"
+actix-rt = "2"
+actix-server = "2.0.0-beta.3"
+actix-service = "2.0.0-beta.4"
+actix-utils = "3.0.0-beta.2"
+actix-tls = { version = "3.0.0-beta.3", default-features = false, optional = true }
 
-actix-web-codegen = "0.3.0"
-actix-http = "2.0.0"
-awc = { version = "2.0.0", default-features = false }
+actix-web-codegen = "0.5.0-beta.1"
+actix-http = "3.0.0-beta.3"
+awc = { version = "3.0.0-beta.2", default-features = false }
 
-bytes = "0.5.3"
-derive_more = "0.99.2"
+ahash = "0.7"
+bytes = "1"
+derive_more = "0.99.5"
+either = "1.5.3"
 encoding_rs = "0.8"
-futures-channel = { version = "0.3.5", default-features = false }
-futures-core = { version = "0.3.5", default-features = false }
-futures-util = { version = "0.3.5", default-features = false }
-fxhash = "0.2.1"
+futures-core = { version = "0.3.7", default-features = false }
+futures-util = { version = "0.3.7", default-features = false }
 log = "0.4"
 mime = "0.3"
-socket2 = "0.3"
-pin-project = "0.4.17"
-regex = "1.3"
+pin-project = "1.0.0"
+regex = "1.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-serde_urlencoded = "0.6.1"
-time = { version = "0.2.7", default-features = false, features = ["std"] }
+serde_urlencoded = "0.7"
+smallvec = "1.6"
+socket2 = "0.3.16"
+time = { version = "0.2.23", default-features = false, features = ["std"] }
+tls-openssl = { package = "openssl", version = "0.10.9", optional = true }
+tls-rustls = { package = "rustls", version = "0.19.0", optional = true }
 url = "2.1"
-open-ssl = { package = "openssl", version = "0.10", optional = true }
-rust-tls = { package = "rustls", version = "0.18.0", optional = true }
-tinyvec = { version = "1", features = ["alloc"] }
+
+[target.'cfg(windows)'.dependencies.tls-openssl]
+version = "0.10.9"
+package = "openssl"
+features = ["vendored"]
+optional = true
 
 [dev-dependencies]
-actix = "0.10.0"
-actix-http = { version = "2.0.0", features = ["actors"] }
-rand = "0.7"
-env_logger = "0.7"
-serde_derive = "1.0"
 brotli2 = "0.3.2"
-flate2 = "1.0.13"
 criterion = "0.3"
+env_logger = "0.8"
+flate2 = "1.0.13"
+rand = "0.8"
+rcgen = "0.8"
+serde_derive = "1.0"
 
 [profile.release]
 lto = true
@@ -119,16 +134,13 @@ codegen-units = 1
 [patch.crates-io]
 actix-web = { path = "." }
 actix-http = { path = "actix-http" }
-actix-http-test = { path = "test-server" }
+actix-http-test = { path = "actix-http-test" }
+actix-web-actors = { path = "actix-web-actors" }
 actix-web-codegen = { path = "actix-web-codegen" }
-actix-files = { path = "actix-files" }
 actix-multipart = { path = "actix-multipart" }
+actix-files = { path = "actix-files" }
 awc = { path = "awc" }
 
-[[example]]
-name = "client"
-required-features = ["rustls"]
-
 [[bench]]
 name = "server"
 harness = false
@@ -136,3 +148,7 @@ harness = false
 [[bench]]
 name = "service"
 harness = false
+
+[[bench]]
+name = "responder"
+harness = false
diff --git a/MIGRATION.md b/MIGRATION.md
index 5c4650194..e01702868 100644
--- a/MIGRATION.md
+++ b/MIGRATION.md
@@ -1,5 +1,15 @@
 ## Unreleased
 
+* The default `NormalizePath` behavior now strips trailing slashes by default. This was
+  previously documented to be the case in v3 but the behavior now matches. The effect is that
+  routes defined with trailing slashes will become inaccessible when
+  using `NormalizePath::default()`.
+  
+  Before: `#[get("/test/")`  
+  After: `#[get("/test")`  
+
+  Alternatively, explicitly require trailing slashes: `NormalizePath::new(TrailingSlash::Always)`.
+
 
 ## 3.0.0
 
diff --git a/README.md b/README.md
index 3e3ce8bf1..bf68e7961 100644
--- a/README.md
+++ b/README.md
@@ -1,19 +1,20 @@
 <div align="center">
-  <h1>Actix web</h1>
+  <h1>Actix Web</h1>
   <p>
-    <strong>Actix web is a powerful, pragmatic, and extremely fast web framework for Rust</strong>
+    <strong>Actix Web is a powerful, pragmatic, and extremely fast web framework for Rust</strong>
   </p>
   <p>
 
-[![crates.io](https://meritbadge.herokuapp.com/actix-web)](https://crates.io/crates/actix-web)
-[![Documentation](https://docs.rs/actix-web/badge.svg)](https://docs.rs/actix-web)
-[![Version](https://img.shields.io/badge/rustc-1.42+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.42.html)
-![License](https://img.shields.io/crates/l/actix-web.svg)
+[![crates.io](https://img.shields.io/crates/v/actix-web?label=latest)](https://crates.io/crates/actix-web)
+[![Documentation](https://docs.rs/actix-web/badge.svg?version=4.0.0-beta.2)](https://docs.rs/actix-web/4.0.0-beta.2)
+[![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
+![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/actix-web.svg)
+[![Dependency Status](https://deps.rs/crate/actix-web/4.0.0-beta.2/status.svg)](https://deps.rs/crate/actix-web/4.0.0-beta.2)
 <br />
-[![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web) 
+[![build status](https://github.com/actix/actix-web/workflows/CI%20%28Linux%29/badge.svg?branch=master&event=push)](https://github.com/actix/actix-web/actions)
 [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) 
-[![Download](https://img.shields.io/crates/d/actix-web.svg)](https://crates.io/crates/actix-web)
-[![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+![downloads](https://img.shields.io/crates/d/actix-web.svg)
+[![Chat on Discord](https://img.shields.io/discord/771444961383153695?label=chat&logo=discord)](https://discord.gg/NWpN5mmg3x)
 
   </p>
 </div>
@@ -30,9 +31,8 @@
 * Static assets
 * SSL support using OpenSSL or Rustls
 * Middlewares ([Logger, Session, CORS, etc](https://actix.rs/docs/middleware/))
-* Includes an async [HTTP client](https://actix.rs/actix-web/actix_web/client/index.html)
-* Supports [Actix actor framework](https://github.com/actix/actix)
-* Runs on stable Rust 1.42+
+* Includes an async [HTTP client](https://docs.rs/actix-web/latest/actix_web/client/index.html)
+* Runs on stable Rust 1.46+
 
 ## Documentation
 
@@ -97,13 +97,13 @@ One of the fastest web frameworks available according to the
 This project is licensed under either of
 
 * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
-  [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0))
+  [http://www.apache.org/licenses/LICENSE-2.0])
 * MIT license ([LICENSE-MIT](LICENSE-MIT) or
-  [http://opensource.org/licenses/MIT](http://opensource.org/licenses/MIT))
+  [http://opensource.org/licenses/MIT])
 
 at your option.
 
 ## Code of Conduct
 
-Contribution to the actix-web crate is organized under the terms of the Contributor Covenant, the
-maintainers of Actix web, promises to intervene to uphold that code of conduct.
+Contribution to the actix-web repo is organized under the terms of the Contributor Covenant.
+The Actix team promises to intervene to uphold that code of conduct.
diff --git a/actix-files/CHANGES.md b/actix-files/CHANGES.md
index 75d616ff9..6e2a241ac 100644
--- a/actix-files/CHANGES.md
+++ b/actix-files/CHANGES.md
@@ -1,12 +1,49 @@
 # Changes
 
-## [Unreleased] - 2020-xx-xx
+## Unreleased - 2021-xx-xx
 
-## [0.3.0-beta.1] - 2020-07-15
+
+## 0.6.0-beta.2 - 2021-02-10
+* Fix If-Modified-Since and If-Unmodified-Since to not compare using sub-second timestamps. [#1887]
+* Replace `v_htmlescape` with `askama_escape`. [#1953]
+
+[#1887]: https://github.com/actix/actix-web/pull/1887
+[#1953]: https://github.com/actix/actix-web/pull/1953
+
+
+## 0.6.0-beta.1 - 2021-01-07
+* `HttpRange::parse` now has its own error type.
+* Update `bytes` to `1.0`. [#1813]
+
+[#1813]: https://github.com/actix/actix-web/pull/1813
+
+
+## 0.5.0 - 2020-12-26
+* Optionally support hidden files/directories. [#1811]
+
+[#1811]: https://github.com/actix/actix-web/pull/1811
+
+
+## 0.4.1 - 2020-11-24
+* Clarify order of parameters in `Files::new` and improve docs.
+
+
+## 0.4.0 - 2020-10-06
+* Add `Files::prefer_utf8` option that adds UTF-8 charset on certain response types. [#1714]
+
+[#1714]: https://github.com/actix/actix-web/pull/1714
+
+
+## 0.3.0 - 2020-09-11
+* No significant changes from 0.3.0-beta.1.
+
+
+## 0.3.0-beta.1 - 2020-07-15
 * Update `v_htmlescape` to 0.10
 * Update `actix-web` and `actix-http` dependencies to beta.1
 
-## [0.3.0-alpha.1] - 2020-05-23
+
+## 0.3.0-alpha.1 - 2020-05-23
 * Update `actix-web` and `actix-http` dependencies to alpha
 * Fix some typos in the docs
 * Bump minimum supported Rust version to 1.40
@@ -14,77 +51,73 @@
 
 [#1384]: https://github.com/actix/actix-web/pull/1384
 
-## [0.2.1] - 2019-12-22
 
+## 0.2.1 - 2019-12-22
 * Use the same format for file URLs regardless of platforms
 
-## [0.2.0] - 2019-12-20
 
+## 0.2.0 - 2019-12-20
 * Fix BodyEncoding trait import #1220
 
-## [0.2.0-alpha.1] - 2019-12-07
 
+## 0.2.0-alpha.1 - 2019-12-07
 * Migrate to `std::future`
 
-## [0.1.7] - 2019-11-06
 
-* Add an additional `filename*` param in the `Content-Disposition` header of `actix_files::NamedFile` to be more compatible. (#1151)
-
-## [0.1.6] - 2019-10-14
+## 0.1.7 - 2019-11-06
+* Add an additional `filename*` param in the `Content-Disposition` header of
+  `actix_files::NamedFile` to be more compatible. (#1151)
 
+## 0.1.6 - 2019-10-14
 * Add option to redirect to a slash-ended path `Files` #1132
 
-## [0.1.5] - 2019-10-08
 
+## 0.1.5 - 2019-10-08
 * Bump up `mime_guess` crate version to 2.0.1
-
 * Bump up `percent-encoding` crate version to 2.1
-
 * Allow user defined request guards for `Files` #1113
 
-## [0.1.4] - 2019-07-20
 
+## 0.1.4 - 2019-07-20
 * Allow to disable `Content-Disposition` header #686
 
-## [0.1.3] - 2019-06-28
 
+## 0.1.3 - 2019-06-28
 * Do not set `Content-Length` header, let actix-http set it #930
 
-## [0.1.2] - 2019-06-13
 
+## 0.1.2 - 2019-06-13
 * Content-Length is 0 for NamedFile HEAD request #914
-
 * Fix ring dependency from actix-web default features for #741
 
-## [0.1.1] - 2019-06-01
 
+## 0.1.1 - 2019-06-01
 * Static files are incorrectly served as both chunked and with length #812
 
-## [0.1.0] - 2019-05-25
 
-* NamedFile last-modified check always fails due to nano-seconds
-  in file modified date #820
+## 0.1.0 - 2019-05-25
+* NamedFile last-modified check always fails due to nano-seconds in file modified date #820
 
-## [0.1.0-beta.4] - 2019-05-12
 
+## 0.1.0-beta.4 - 2019-05-12
 * Update actix-web to beta.4
 
-## [0.1.0-beta.1] - 2019-04-20
 
+## 0.1.0-beta.1 - 2019-04-20
 * Update actix-web to beta.1
 
-## [0.1.0-alpha.6] - 2019-04-14
 
+## 0.1.0-alpha.6 - 2019-04-14
 * Update actix-web to alpha6
 
-## [0.1.0-alpha.4] - 2019-04-08
 
+## 0.1.0-alpha.4 - 2019-04-08
 * Update actix-web to alpha4
 
-## [0.1.0-alpha.2] - 2019-04-02
 
+## 0.1.0-alpha.2 - 2019-04-02
 * Add default handler support
 
-## [0.1.0-alpha.1] - 2019-03-28
 
+## 0.1.0-alpha.1 - 2019-03-28
 * Initial impl
diff --git a/actix-files/Cargo.toml b/actix-files/Cargo.toml
index 634296c56..08b7b36fc 100644
--- a/actix-files/Cargo.toml
+++ b/actix-files/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "actix-files"
-version = "0.3.0"
+version = "0.6.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
-description = "Static files support for actix web."
+description = "Static file serving for Actix Web"
 readme = "README.md"
 keywords = ["actix", "http", "async", "futures"]
 homepage = "https://actix.rs"
@@ -17,19 +17,21 @@ name = "actix_files"
 path = "src/lib.rs"
 
 [dependencies]
-actix-web = { version = "3.0.0", default-features = false }
-actix-service = "1.0.6"
+actix-web = { version = "4.0.0-beta.3", default-features = false }
+actix-service = "2.0.0-beta.4"
+
+askama_escape = "0.10"
 bitflags = "1"
-bytes = "0.5.3"
-futures-core = { version = "0.3.5", default-features = false }
-futures-util = { version = "0.3.5", default-features = false }
-derive_more = "0.99.2"
+bytes = "1"
+futures-core = { version = "0.3.7", default-features = false }
+futures-util = { version = "0.3.7", default-features = false }
+http-range = "0.1.4"
+derive_more = "0.99.5"
 log = "0.4"
 mime = "0.3"
 mime_guess = "2.0.1"
 percent-encoding = "2.1"
-v_htmlescape = "0.10"
 
 [dev-dependencies]
-actix-rt = "1.0.0"
-actix-web = { version = "3.0.0", features = ["openssl"] }
+actix-rt = "2"
+actix-web = "4.0.0-beta.3"
diff --git a/actix-files/README.md b/actix-files/README.md
index 5a5a62083..463f20224 100644
--- a/actix-files/README.md
+++ b/actix-files/README.md
@@ -1,9 +1,19 @@
-# Static files support for actix web [![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web) [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) [![crates.io](https://meritbadge.herokuapp.com/actix-files)](https://crates.io/crates/actix-files) [![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+# actix-files
 
-## Documentation & community resources
+> Static file serving for Actix Web
 
-* [User Guide](https://actix.rs/docs/)
-* [API Documentation](https://docs.rs/actix-files/)
-* [Chat on gitter](https://gitter.im/actix/actix)
-* Cargo package: [actix-files](https://crates.io/crates/actix-files)
-* Minimum supported Rust version: 1.40 or later
+[![crates.io](https://img.shields.io/crates/v/actix-files?label=latest)](https://crates.io/crates/actix-files)
+[![Documentation](https://docs.rs/actix-files/badge.svg?version=0.5.0)](https://docs.rs/actix-files/0.5.0)
+[![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
+![License](https://img.shields.io/crates/l/actix-files.svg)
+<br />
+[![dependency status](https://deps.rs/crate/actix-files/0.5.0/status.svg)](https://deps.rs/crate/actix-files/0.5.0)
+[![Download](https://img.shields.io/crates/d/actix-files.svg)](https://crates.io/crates/actix-files)
+[![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
+## Documentation & Resources
+
+- [API Documentation](https://docs.rs/actix-files/)
+- [Example Project](https://github.com/actix/examples/tree/master/static_index)
+- [Chat on Gitter](https://gitter.im/actix/actix-web)
+- Minimum supported Rust version: 1.46 or later
diff --git a/actix-files/src/chunked.rs b/actix-files/src/chunked.rs
index 580b06787..f639848c9 100644
--- a/actix-files/src/chunked.rs
+++ b/actix-files/src/chunked.rs
@@ -9,26 +9,35 @@ use std::{
 
 use actix_web::{
     error::{BlockingError, Error},
-    web,
+    rt::task::{spawn_blocking, JoinHandle},
 };
 use bytes::Bytes;
 use futures_core::{ready, Stream};
-use futures_util::future::{FutureExt, LocalBoxFuture};
-
-use crate::handle_error;
-
-type ChunkedBoxFuture =
-    LocalBoxFuture<'static, Result<(File, Bytes), BlockingError<io::Error>>>;
 
 #[doc(hidden)]
 /// A helper created from a `std::fs::File` which reads the file
 /// chunk-by-chunk on a `ThreadPool`.
 pub struct ChunkedReadFile {
-    pub(crate) size: u64,
-    pub(crate) offset: u64,
-    pub(crate) file: Option<File>,
-    pub(crate) fut: Option<ChunkedBoxFuture>,
-    pub(crate) counter: u64,
+    size: u64,
+    offset: u64,
+    state: ChunkedReadFileState,
+    counter: u64,
+}
+
+enum ChunkedReadFileState {
+    File(Option<File>),
+    Future(JoinHandle<Result<(File, Bytes), io::Error>>),
+}
+
+impl ChunkedReadFile {
+    pub(crate) fn new(size: u64, offset: u64, file: File) -> Self {
+        Self {
+            size,
+            offset,
+            state: ChunkedReadFileState::File(Some(file)),
+            counter: 0,
+        }
+    }
 }
 
 impl fmt::Debug for ChunkedReadFile {
@@ -40,55 +49,50 @@ impl fmt::Debug for ChunkedReadFile {
 impl Stream for ChunkedReadFile {
     type Item = Result<Bytes, Error>;
 
-    fn poll_next(
-        mut self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
-        if let Some(ref mut fut) = self.fut {
-            return match ready!(Pin::new(fut).poll(cx)) {
-                Ok((file, bytes)) => {
-                    self.fut.take();
-                    self.file = Some(file);
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        let this = self.as_mut().get_mut();
+        match this.state {
+            ChunkedReadFileState::File(ref mut file) => {
+                let size = this.size;
+                let offset = this.offset;
+                let counter = this.counter;
 
-                    self.offset += bytes.len() as u64;
-                    self.counter += bytes.len() as u64;
+                if size == counter {
+                    Poll::Ready(None)
+                } else {
+                    let mut file = file
+                        .take()
+                        .expect("ChunkedReadFile polled after completion");
 
-                    Poll::Ready(Some(Ok(bytes)))
+                    let fut = spawn_blocking(move || {
+                        let max_bytes = cmp::min(size.saturating_sub(counter), 65_536) as usize;
+
+                        let mut buf = Vec::with_capacity(max_bytes);
+                        file.seek(io::SeekFrom::Start(offset))?;
+
+                        let n_bytes =
+                            file.by_ref().take(max_bytes as u64).read_to_end(&mut buf)?;
+
+                        if n_bytes == 0 {
+                            return Err(io::ErrorKind::UnexpectedEof.into());
+                        }
+
+                        Ok((file, Bytes::from(buf)))
+                    });
+                    this.state = ChunkedReadFileState::Future(fut);
+                    self.poll_next(cx)
                 }
-                Err(e) => Poll::Ready(Some(Err(handle_error(e)))),
-            };
-        }
+            }
+            ChunkedReadFileState::Future(ref mut fut) => {
+                let (file, bytes) =
+                    ready!(Pin::new(fut).poll(cx)).map_err(|_| BlockingError)??;
+                this.state = ChunkedReadFileState::File(Some(file));
 
-        let size = self.size;
-        let offset = self.offset;
-        let counter = self.counter;
+                this.offset += bytes.len() as u64;
+                this.counter += bytes.len() as u64;
 
-        if size == counter {
-            Poll::Ready(None)
-        } else {
-            let mut file = self.file.take().expect("Use after completion");
-
-            self.fut = Some(
-                web::block(move || {
-                    let max_bytes =
-                        cmp::min(size.saturating_sub(counter), 65_536) as usize;
-
-                    let mut buf = Vec::with_capacity(max_bytes);
-                    file.seek(io::SeekFrom::Start(offset))?;
-
-                    let n_bytes =
-                        file.by_ref().take(max_bytes as u64).read_to_end(&mut buf)?;
-
-                    if n_bytes == 0 {
-                        return Err(io::ErrorKind::UnexpectedEof.into());
-                    }
-
-                    Ok((file, Bytes::from(buf)))
-                })
-                .boxed_local(),
-            );
-
-            self.poll_next(cx)
+                Poll::Ready(Some(Ok(bytes)))
+            }
         }
     }
 }
diff --git a/actix-files/src/directory.rs b/actix-files/src/directory.rs
index 3717985d3..80e0c98d0 100644
--- a/actix-files/src/directory.rs
+++ b/actix-files/src/directory.rs
@@ -1,8 +1,8 @@
 use std::{fmt::Write, fs::DirEntry, io, path::Path, path::PathBuf};
 
 use actix_web::{dev::ServiceResponse, HttpRequest, HttpResponse};
+use askama_escape::{escape as escape_html_entity, Html};
 use percent_encoding::{utf8_percent_encode, CONTROLS};
-use v_htmlescape::escape as escape_html_entity;
 
 /// A directory; responds with the generated directory listing.
 #[derive(Debug)]
@@ -50,7 +50,7 @@ macro_rules! encode_file_url {
 // " -- &quot;  & -- &amp;  ' -- &#x27;  < -- &lt;  > -- &gt;  / -- &#x2f;
 macro_rules! encode_file_name {
     ($entry:ident) => {
-        escape_html_entity(&$entry.file_name().to_string_lossy())
+        escape_html_entity(&$entry.file_name().to_string_lossy(), Html)
     };
 }
 
@@ -66,9 +66,7 @@ pub(crate) fn directory_listing(
         if dir.is_visible(&entry) {
             let entry = entry.unwrap();
             let p = match entry.path().strip_prefix(&dir.path) {
-                Ok(p) if cfg!(windows) => {
-                    base.join(p).to_string_lossy().replace("\\", "/")
-                }
+                Ok(p) if cfg!(windows) => base.join(p).to_string_lossy().replace("\\", "/"),
                 Ok(p) => base.join(p).to_string_lossy().into_owned(),
                 Err(_) => continue,
             };
diff --git a/actix-files/src/encoding.rs b/actix-files/src/encoding.rs
new file mode 100644
index 000000000..95997e313
--- /dev/null
+++ b/actix-files/src/encoding.rs
@@ -0,0 +1,52 @@
+use mime::Mime;
+
+/// Transforms MIME `text/*` types into their UTF-8 equivalent, if supported.
+///
+/// MIME types that are converted
+/// - application/javascript
+/// - text/html
+/// - text/css
+/// - text/plain
+/// - text/csv
+/// - text/tab-separated-values
+pub(crate) fn equiv_utf8_text(ct: Mime) -> Mime {
+    // use (roughly) order of file-type popularity for a web server
+
+    if ct == mime::APPLICATION_JAVASCRIPT {
+        return mime::APPLICATION_JAVASCRIPT_UTF_8;
+    }
+
+    if ct == mime::TEXT_HTML {
+        return mime::TEXT_HTML_UTF_8;
+    }
+
+    if ct == mime::TEXT_CSS {
+        return mime::TEXT_CSS_UTF_8;
+    }
+
+    if ct == mime::TEXT_PLAIN {
+        return mime::TEXT_PLAIN_UTF_8;
+    }
+
+    if ct == mime::TEXT_CSV {
+        return mime::TEXT_CSV_UTF_8;
+    }
+
+    if ct == mime::TEXT_TAB_SEPARATED_VALUES {
+        return mime::TEXT_TAB_SEPARATED_VALUES_UTF_8;
+    }
+
+    ct
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_equiv_utf8_text() {
+        assert_eq!(equiv_utf8_text(mime::TEXT_PLAIN), mime::TEXT_PLAIN_UTF_8);
+        assert_eq!(equiv_utf8_text(mime::TEXT_XML), mime::TEXT_XML);
+        assert_eq!(equiv_utf8_text(mime::IMAGE_PNG), mime::IMAGE_PNG);
+    }
+}
diff --git a/actix-files/src/files.rs b/actix-files/src/files.rs
index 2b55e1aa9..6f8b28bbf 100644
--- a/actix-files/src/files.rs
+++ b/actix-files/src/files.rs
@@ -1,10 +1,8 @@
 use std::{cell::RefCell, fmt, io, path::PathBuf, rc::Rc};
 
-use actix_service::{boxed, IntoServiceFactory, ServiceFactory};
+use actix_service::{boxed, IntoServiceFactory, ServiceFactory, ServiceFactoryExt};
 use actix_web::{
-    dev::{
-        AppService, HttpServiceFactory, ResourceDef, ServiceRequest, ServiceResponse,
-    },
+    dev::{AppService, HttpServiceFactory, ResourceDef, ServiceRequest, ServiceResponse},
     error::Error,
     guard::Guard,
     http::header::DispositionType,
@@ -13,8 +11,8 @@ use actix_web::{
 use futures_util::future::{ok, FutureExt, LocalBoxFuture};
 
 use crate::{
-    directory_listing, named, Directory, DirectoryRenderer, FilesService,
-    HttpNewService, MimeOverride,
+    directory_listing, named, Directory, DirectoryRenderer, FilesService, HttpNewService,
+    MimeOverride,
 };
 
 /// Static files handling service.
@@ -39,6 +37,7 @@ pub struct Files {
     mime_override: Option<Rc<MimeOverride>>,
     file_flags: named::Flags,
     guards: Option<Rc<dyn Guard>>,
+    hidden_files: bool,
 }
 
 impl fmt::Debug for Files {
@@ -60,18 +59,32 @@ impl Clone for Files {
             path: self.path.clone(),
             mime_override: self.mime_override.clone(),
             guards: self.guards.clone(),
+            hidden_files: self.hidden_files,
         }
     }
 }
 
 impl Files {
-    /// Create new `Files` instance for specified base directory.
+    /// Create new `Files` instance for a specified base directory.
     ///
-    /// `File` uses `ThreadPool` for blocking filesystem operations.
-    /// By default pool with 5x threads of available cpus is used.
-    /// Pool size can be changed by setting ACTIX_THREADPOOL environment variable.
-    pub fn new<T: Into<PathBuf>>(path: &str, dir: T) -> Files {
-        let orig_dir = dir.into();
+    /// # Argument Order
+    /// The first argument (`mount_path`) is the root URL at which the static files are served.
+    /// For example, `/assets` will serve files at `example.com/assets/...`.
+    ///
+    /// The second argument (`serve_from`) is the location on disk at which files are loaded.
+    /// This can be a relative path. For example, `./` would serve files from the current
+    /// working directory.
+    ///
+    /// # Implementation Notes
+    /// If the mount path is set as the root path `/`, services registered after this one will
+    /// be inaccessible. Register more specific handlers and services first.
+    ///
+    /// `Files` uses a threadpool for blocking filesystem operations. By default, the pool uses a
+    /// max number of threads equal to `512 * HttpServer::worker`. Real time thread count are
+    /// adjusted with work load. More threads would spawn when need and threads goes idle for a
+    /// period of time would be de-spawned.
+    pub fn new<T: Into<PathBuf>>(mount_path: &str, serve_from: T) -> Files {
+        let orig_dir = serve_from.into();
         let dir = match orig_dir.canonicalize() {
             Ok(canon_dir) => canon_dir,
             Err(_) => {
@@ -81,7 +94,7 @@ impl Files {
         };
 
         Files {
-            path: path.to_string(),
+            path: mount_path.to_owned(),
             directory: dir,
             index: None,
             show_index: false,
@@ -91,6 +104,7 @@ impl Files {
             mime_override: None,
             file_flags: named::Flags::default(),
             guards: None,
+            hidden_files: false,
         }
     }
 
@@ -113,8 +127,8 @@ impl Files {
     /// Set custom directory renderer
     pub fn files_listing_renderer<F>(mut self, f: F) -> Self
     where
-        for<'r, 's> F: Fn(&'r Directory, &'s HttpRequest) -> Result<ServiceResponse, io::Error>
-            + 'static,
+        for<'r, 's> F:
+            Fn(&'r Directory, &'s HttpRequest) -> Result<ServiceResponse, io::Error> + 'static,
     {
         self.renderer = Rc::new(f);
         self
@@ -138,24 +152,33 @@ impl Files {
         self
     }
 
-    #[inline]
     /// Specifies whether to use ETag or not.
     ///
     /// Default is true.
+    #[inline]
     pub fn use_etag(mut self, value: bool) -> Self {
         self.file_flags.set(named::Flags::ETAG, value);
         self
     }
 
-    #[inline]
     /// Specifies whether to use Last-Modified or not.
     ///
     /// Default is true.
+    #[inline]
     pub fn use_last_modified(mut self, value: bool) -> Self {
         self.file_flags.set(named::Flags::LAST_MD, value);
         self
     }
 
+    /// Specifies whether text responses should signal a UTF-8 encoding.
+    ///
+    /// Default is false (but will default to true in a future version).
+    #[inline]
+    pub fn prefer_utf8(mut self, value: bool) -> Self {
+        self.file_flags.set(named::Flags::PREFER_UTF8, value);
+        self
+    }
+
     /// Specifies custom guards to use for directory listings and files.
     ///
     /// Default behaviour allows GET and HEAD.
@@ -177,10 +200,10 @@ impl Files {
     /// Sets default handler which is used when no matched file could be found.
     pub fn default_handler<F, U>(mut self, f: F) -> Self
     where
-        F: IntoServiceFactory<U>,
+        F: IntoServiceFactory<U, ServiceRequest>,
         U: ServiceFactory<
+                ServiceRequest,
                 Config = (),
-                Request = ServiceRequest,
                 Response = ServiceResponse,
                 Error = Error,
             > + 'static,
@@ -192,6 +215,13 @@ impl Files {
 
         self
     }
+
+    /// Enables serving hidden files and directories, allowing a leading dots in url fragments.
+    #[inline]
+    pub fn use_hidden_files(mut self) -> Self {
+        self.hidden_files = true;
+        self
+    }
 }
 
 impl HttpServiceFactory for Files {
@@ -210,8 +240,7 @@ impl HttpServiceFactory for Files {
     }
 }
 
-impl ServiceFactory for Files {
-    type Request = ServiceRequest;
+impl ServiceFactory<ServiceRequest> for Files {
     type Response = ServiceResponse;
     type Error = Error;
     type Config = ();
@@ -230,6 +259,7 @@ impl ServiceFactory for Files {
             mime_override: self.mime_override.clone(),
             file_flags: self.file_flags,
             guards: self.guards.clone(),
+            hidden_files: self.hidden_files,
         };
 
         if let Some(ref default) = *self.default.borrow() {
diff --git a/actix-files/src/lib.rs b/actix-files/src/lib.rs
index 1fc7cb3f3..04dd9f07f 100644
--- a/actix-files/src/lib.rs
+++ b/actix-files/src/lib.rs
@@ -1,4 +1,4 @@
-//! Static files support for Actix Web.
+//! Static file serving for Actix Web.
 //!
 //! Provides a non-blocking service for serving static files from disk.
 //!
@@ -8,28 +8,23 @@
 //! use actix_files::Files;
 //!
 //! let app = App::new()
-//!     .service(Files::new("/static", "."));
+//!     .service(Files::new("/static", ".").prefer_utf8(true));
 //! ```
-//!
-//! # Implementation Quirks
-//! - If a filename contains non-ascii characters, that file will be served with the `charset=utf-8`
-//!   extension on the Content-Type header.
 
 #![deny(rust_2018_idioms)]
 #![warn(missing_docs, missing_debug_implementations)]
 
-use std::io;
-
 use actix_service::boxed::{BoxService, BoxServiceFactory};
 use actix_web::{
     dev::{ServiceRequest, ServiceResponse},
-    error::{BlockingError, Error, ErrorInternalServerError},
+    error::Error,
     http::header::DispositionType,
 };
 use mime_guess::from_ext;
 
 mod chunked;
 mod directory;
+mod encoding;
 mod error;
 mod files;
 mod named;
@@ -59,13 +54,6 @@ pub fn file_extension_to_mime(ext: &str) -> mime::Mime {
     from_ext(ext).first_or_octet_stream()
 }
 
-pub(crate) fn handle_error(err: BlockingError<io::Error>) -> Error {
-    match err {
-        BlockingError::Error(err) => err.into(),
-        BlockingError::Canceled => ErrorInternalServerError("Unexpected error"),
-    }
-}
-
 type MimeOverride = dyn Fn(&mime::Name<'_>) -> DispositionType;
 
 #[cfg(test)]
@@ -85,7 +73,8 @@ mod tests {
         },
         middleware::Compress,
         test::{self, TestRequest},
-        web, App, HttpResponse, Responder,
+        web::{self, Bytes},
+        App, HttpResponse, Responder,
     };
     use futures_util::future::ok;
 
@@ -93,6 +82,9 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_file_extension_to_mime() {
+        let m = file_extension_to_mime("");
+        assert_eq!(m, mime::APPLICATION_OCTET_STREAM);
+
         let m = file_extension_to_mime("jpg");
         assert_eq!(m, mime::IMAGE_JPEG);
 
@@ -106,11 +98,22 @@ mod tests {
     #[actix_rt::test]
     async fn test_if_modified_since_without_if_none_match() {
         let file = NamedFile::open("Cargo.toml").unwrap();
-        let since =
-            header::HttpDate::from(SystemTime::now().add(Duration::from_secs(60)));
+        let since = header::HttpDate::from(SystemTime::now().add(Duration::from_secs(60)));
 
         let req = TestRequest::default()
-            .header(header::IF_MODIFIED_SINCE, since)
+            .insert_header((header::IF_MODIFIED_SINCE, since))
+            .to_http_request();
+        let resp = file.respond_to(&req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::NOT_MODIFIED);
+    }
+
+    #[actix_rt::test]
+    async fn test_if_modified_since_without_if_none_match_same() {
+        let file = NamedFile::open("Cargo.toml").unwrap();
+        let since = file.last_modified().unwrap();
+
+        let req = TestRequest::default()
+            .insert_header((header::IF_MODIFIED_SINCE, since))
             .to_http_request();
         let resp = file.respond_to(&req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::NOT_MODIFIED);
@@ -119,17 +122,40 @@ mod tests {
     #[actix_rt::test]
     async fn test_if_modified_since_with_if_none_match() {
         let file = NamedFile::open("Cargo.toml").unwrap();
-        let since =
-            header::HttpDate::from(SystemTime::now().add(Duration::from_secs(60)));
+        let since = header::HttpDate::from(SystemTime::now().add(Duration::from_secs(60)));
 
         let req = TestRequest::default()
-            .header(header::IF_NONE_MATCH, "miss_etag")
-            .header(header::IF_MODIFIED_SINCE, since)
+            .insert_header((header::IF_NONE_MATCH, "miss_etag"))
+            .insert_header((header::IF_MODIFIED_SINCE, since))
             .to_http_request();
         let resp = file.respond_to(&req).await.unwrap();
         assert_ne!(resp.status(), StatusCode::NOT_MODIFIED);
     }
 
+    #[actix_rt::test]
+    async fn test_if_unmodified_since() {
+        let file = NamedFile::open("Cargo.toml").unwrap();
+        let since = file.last_modified().unwrap();
+
+        let req = TestRequest::default()
+            .insert_header((header::IF_UNMODIFIED_SINCE, since))
+            .to_http_request();
+        let resp = file.respond_to(&req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
+    }
+
+    #[actix_rt::test]
+    async fn test_if_unmodified_since_failed() {
+        let file = NamedFile::open("Cargo.toml").unwrap();
+        let since = header::HttpDate::from(SystemTime::UNIX_EPOCH);
+
+        let req = TestRequest::default()
+            .insert_header((header::IF_UNMODIFIED_SINCE, since))
+            .to_http_request();
+        let resp = file.respond_to(&req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::PRECONDITION_FAILED);
+    }
+
     #[actix_rt::test]
     async fn test_named_file_text() {
         assert!(NamedFile::open("test--").is_err());
@@ -184,8 +210,7 @@ mod tests {
     #[actix_rt::test]
     async fn test_named_file_non_ascii_file_name() {
         let mut file =
-            NamedFile::from_file(File::open("Cargo.toml").unwrap(), "貨物.toml")
-                .unwrap();
+            NamedFile::from_file(File::open("Cargo.toml").unwrap(), "貨物.toml").unwrap();
         {
             file.file();
             let _f: &File = &file;
@@ -338,7 +363,7 @@ mod tests {
             DispositionType::Attachment
         }
 
-        let mut srv = test::init_service(
+        let srv = test::init_service(
             App::new().service(
                 Files::new("/", ".")
                     .mime_override(all_attachment)
@@ -348,7 +373,7 @@ mod tests {
         .await;
 
         let request = TestRequest::get().uri("/").to_request();
-        let response = test::call_service(&mut srv, request).await;
+        let response = test::call_service(&srv, request).await;
         assert_eq!(response.status(), StatusCode::OK);
 
         let content_disposition = response
@@ -363,7 +388,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_named_file_ranges_status_code() {
-        let mut srv = test::init_service(
+        let srv = test::init_service(
             App::new().service(Files::new("/test", ".").index_file("Cargo.toml")),
         )
         .await;
@@ -371,17 +396,17 @@ mod tests {
         // Valid range header
         let request = TestRequest::get()
             .uri("/t%65st/Cargo.toml")
-            .header(header::RANGE, "bytes=10-20")
+            .insert_header((header::RANGE, "bytes=10-20"))
             .to_request();
-        let response = test::call_service(&mut srv, request).await;
+        let response = test::call_service(&srv, request).await;
         assert_eq!(response.status(), StatusCode::PARTIAL_CONTENT);
 
         // Invalid range header
         let request = TestRequest::get()
             .uri("/t%65st/Cargo.toml")
-            .header(header::RANGE, "bytes=1-0")
+            .insert_header((header::RANGE, "bytes=1-0"))
             .to_request();
-        let response = test::call_service(&mut srv, request).await;
+        let response = test::call_service(&srv, request).await;
 
         assert_eq!(response.status(), StatusCode::RANGE_NOT_SATISFIABLE);
     }
@@ -393,7 +418,7 @@ mod tests {
         // Valid range header
         let response = srv
             .get("/tests/test.binary")
-            .header(header::RANGE, "bytes=10-20")
+            .insert_header((header::RANGE, "bytes=10-20"))
             .send()
             .await
             .unwrap();
@@ -403,7 +428,7 @@ mod tests {
         // Invalid range header
         let response = srv
             .get("/tests/test.binary")
-            .header(header::RANGE, "bytes=10-5")
+            .insert_header((header::RANGE, "bytes=10-5"))
             .send()
             .await
             .unwrap();
@@ -418,7 +443,7 @@ mod tests {
         // Valid range header
         let response = srv
             .get("/tests/test.binary")
-            .header(header::RANGE, "bytes=10-20")
+            .insert_header((header::RANGE, "bytes=10-20"))
             .send()
             .await
             .unwrap();
@@ -428,7 +453,7 @@ mod tests {
         // Valid range header, starting from 0
         let response = srv
             .get("/tests/test.binary")
-            .header(header::RANGE, "bytes=0-20")
+            .insert_header((header::RANGE, "bytes=0-20"))
             .send()
             .await
             .unwrap();
@@ -468,14 +493,14 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_static_files_with_spaces() {
-        let mut srv = test::init_service(
+        let srv = test::init_service(
             App::new().service(Files::new("/", ".").index_file("Cargo.toml")),
         )
         .await;
         let request = TestRequest::get()
             .uri("/tests/test%20space.binary")
             .to_request();
-        let response = test::call_service(&mut srv, request).await;
+        let response = test::call_service(&srv, request).await;
         assert_eq!(response.status(), StatusCode::OK);
 
         let bytes = test::read_body(response).await;
@@ -485,28 +510,28 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_files_not_allowed() {
-        let mut srv = test::init_service(App::new().service(Files::new("/", "."))).await;
+        let srv = test::init_service(App::new().service(Files::new("/", "."))).await;
 
         let req = TestRequest::default()
             .uri("/Cargo.toml")
             .method(Method::POST)
             .to_request();
 
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::METHOD_NOT_ALLOWED);
 
-        let mut srv = test::init_service(App::new().service(Files::new("/", "."))).await;
+        let srv = test::init_service(App::new().service(Files::new("/", "."))).await;
         let req = TestRequest::default()
             .method(Method::PUT)
             .uri("/Cargo.toml")
             .to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::METHOD_NOT_ALLOWED);
     }
 
     #[actix_rt::test]
     async fn test_files_guards() {
-        let mut srv = test::init_service(
+        let srv = test::init_service(
             App::new().service(Files::new("/", ".").use_guards(guard::Post())),
         )
         .await;
@@ -516,13 +541,13 @@ mod tests {
             .method(Method::POST)
             .to_request();
 
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 
     #[actix_rt::test]
     async fn test_named_file_content_encoding() {
-        let mut srv = test::init_service(App::new().wrap(Compress::default()).service(
+        let srv = test::init_service(App::new().wrap(Compress::default()).service(
             web::resource("/").to(|| async {
                 NamedFile::open("Cargo.toml")
                     .unwrap()
@@ -533,16 +558,16 @@ mod tests {
 
         let request = TestRequest::get()
             .uri("/")
-            .header(header::ACCEPT_ENCODING, "gzip")
+            .insert_header((header::ACCEPT_ENCODING, "gzip"))
             .to_request();
-        let res = test::call_service(&mut srv, request).await;
+        let res = test::call_service(&srv, request).await;
         assert_eq!(res.status(), StatusCode::OK);
         assert!(!res.headers().contains_key(header::CONTENT_ENCODING));
     }
 
     #[actix_rt::test]
     async fn test_named_file_content_encoding_gzip() {
-        let mut srv = test::init_service(App::new().wrap(Compress::default()).service(
+        let srv = test::init_service(App::new().wrap(Compress::default()).service(
             web::resource("/").to(|| async {
                 NamedFile::open("Cargo.toml")
                     .unwrap()
@@ -553,9 +578,9 @@ mod tests {
 
         let request = TestRequest::get()
             .uri("/")
-            .header(header::ACCEPT_ENCODING, "gzip")
+            .insert_header((header::ACCEPT_ENCODING, "gzip"))
             .to_request();
-        let res = test::call_service(&mut srv, request).await;
+        let res = test::call_service(&srv, request).await;
         assert_eq!(res.status(), StatusCode::OK);
         assert_eq!(
             res.headers()
@@ -577,27 +602,25 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_static_files() {
-        let mut srv = test::init_service(
-            App::new().service(Files::new("/", ".").show_files_listing()),
-        )
-        .await;
+        let srv =
+            test::init_service(App::new().service(Files::new("/", ".").show_files_listing()))
+                .await;
         let req = TestRequest::with_uri("/missing").to_request();
 
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::NOT_FOUND);
 
-        let mut srv = test::init_service(App::new().service(Files::new("/", "."))).await;
+        let srv = test::init_service(App::new().service(Files::new("/", "."))).await;
 
         let req = TestRequest::default().to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::NOT_FOUND);
 
-        let mut srv = test::init_service(
-            App::new().service(Files::new("/", ".").show_files_listing()),
-        )
-        .await;
+        let srv =
+            test::init_service(App::new().service(Files::new("/", ".").show_files_listing()))
+                .await;
         let req = TestRequest::with_uri("/tests").to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
             "text/html; charset=utf-8"
@@ -610,16 +633,16 @@ mod tests {
     #[actix_rt::test]
     async fn test_redirect_to_slash_directory() {
         // should not redirect if no index
-        let mut srv = test::init_service(
+        let srv = test::init_service(
             App::new().service(Files::new("/", ".").redirect_to_slash_directory()),
         )
         .await;
         let req = TestRequest::with_uri("/tests").to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::NOT_FOUND);
 
         // should redirect if index present
-        let mut srv = test::init_service(
+        let srv = test::init_service(
             App::new().service(
                 Files::new("/", ".")
                     .index_file("test.png")
@@ -628,12 +651,12 @@ mod tests {
         )
         .await;
         let req = TestRequest::with_uri("/tests").to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::FOUND);
 
         // should not redirect if the path is wrong
         let req = TestRequest::with_uri("/not_existing").to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::NOT_FOUND);
     }
 
@@ -645,7 +668,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_default_handler_file_missing() {
-        let mut st = Files::new("/", ".")
+        let st = Files::new("/", ".")
             .default_handler(|req: ServiceRequest| {
                 ok(req.into_response(HttpResponse::Ok().body("default content")))
             })
@@ -654,7 +677,7 @@ mod tests {
             .unwrap();
         let req = TestRequest::with_uri("/missing").to_srv_request();
 
-        let resp = test::call_service(&mut st, req).await;
+        let resp = test::call_service(&st, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         let bytes = test::read_body(resp).await;
         assert_eq!(bytes, web::Bytes::from_static(b"default content"));
@@ -723,54 +746,49 @@ mod tests {
     //         );
     //     }
 
-    //     #[actix_rt::test]
-    //     fn integration_serve_index() {
-    //         let mut srv = test::TestServer::with_factory(|| {
-    //             App::new().handler(
-    //                 "test",
-    //                 Files::new(".").index_file("Cargo.toml"),
-    //             )
-    //         });
+    #[actix_rt::test]
+    async fn integration_serve_index() {
+        let srv = test::init_service(
+            App::new().service(Files::new("test", ".").index_file("Cargo.toml")),
+        )
+        .await;
 
-    //         let request = srv.get().uri(srv.url("/test")).finish().unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::OK);
-    //         let bytes = srv.execute(response.body()).unwrap();
-    //         let data = Bytes::from(fs::read("Cargo.toml").unwrap());
-    //         assert_eq!(bytes, data);
+        let req = TestRequest::get().uri("/test").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::OK);
 
-    //         let request = srv.get().uri(srv.url("/test/")).finish().unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::OK);
-    //         let bytes = srv.execute(response.body()).unwrap();
-    //         let data = Bytes::from(fs::read("Cargo.toml").unwrap());
-    //         assert_eq!(bytes, data);
+        let bytes = test::read_body(res).await;
 
-    //         // nonexistent index file
-    //         let request = srv.get().uri(srv.url("/test/unknown")).finish().unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::NOT_FOUND);
+        let data = Bytes::from(fs::read("Cargo.toml").unwrap());
+        assert_eq!(bytes, data);
 
-    //         let request = srv.get().uri(srv.url("/test/unknown/")).finish().unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::NOT_FOUND);
-    //     }
+        let req = TestRequest::get().uri("/test/").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::OK);
 
-    //     #[actix_rt::test]
-    //     fn integration_percent_encoded() {
-    //         let mut srv = test::TestServer::with_factory(|| {
-    //             App::new().handler(
-    //                 "test",
-    //                 Files::new(".").index_file("Cargo.toml"),
-    //             )
-    //         });
+        let bytes = test::read_body(res).await;
+        let data = Bytes::from(fs::read("Cargo.toml").unwrap());
+        assert_eq!(bytes, data);
 
-    //         let request = srv
-    //             .get()
-    //             .uri(srv.url("/test/%43argo.toml"))
-    //             .finish()
-    //             .unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::OK);
-    //     }
+        // nonexistent index file
+        let req = TestRequest::get().uri("/test/unknown").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::NOT_FOUND);
+
+        let req = TestRequest::get().uri("/test/unknown/").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::NOT_FOUND);
+    }
+
+    #[actix_rt::test]
+    async fn integration_percent_encoded() {
+        let srv = test::init_service(
+            App::new().service(Files::new("test", ".").index_file("Cargo.toml")),
+        )
+        .await;
+
+        let req = TestRequest::get().uri("/test/%43argo.toml").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::OK);
+    }
 }
diff --git a/actix-files/src/named.rs b/actix-files/src/named.rs
index 3caa4a809..a688b2e6c 100644
--- a/actix-files/src/named.rs
+++ b/actix-files/src/named.rs
@@ -11,31 +11,30 @@ use actix_web::{
     dev::{BodyEncoding, SizedStream},
     http::{
         header::{
-            self, Charset, ContentDisposition, DispositionParam, DispositionType,
-            ExtendedValue,
+            self, Charset, ContentDisposition, DispositionParam, DispositionType, ExtendedValue,
         },
         ContentEncoding, StatusCode,
     },
-    Error, HttpMessage, HttpRequest, HttpResponse, Responder,
+    HttpMessage, HttpRequest, HttpResponse, Responder,
 };
 use bitflags::bitflags;
-use futures_util::future::{ready, Ready};
 use mime_guess::from_path;
 
-use crate::range::HttpRange;
 use crate::ChunkedReadFile;
+use crate::{encoding::equiv_utf8_text, range::HttpRange};
 
 bitflags! {
     pub(crate) struct Flags: u8 {
-        const ETAG = 0b0000_0001;
-        const LAST_MD = 0b0000_0010;
+        const ETAG =                0b0000_0001;
+        const LAST_MD =             0b0000_0010;
         const CONTENT_DISPOSITION = 0b0000_0100;
+        const PREFER_UTF8 =         0b0000_1000;
     }
 }
 
 impl Default for Flags {
     fn default() -> Self {
-        Flags::all()
+        Flags::from_bits_truncate(0b0000_0111)
     }
 }
 
@@ -92,6 +91,7 @@ impl NamedFile {
             };
 
             let ct = from_path(&path).first_or_octet_stream();
+
             let disposition = match ct.type_() {
                 mime::IMAGE | mime::TEXT | mime::VIDEO => DispositionType::Inline,
                 _ => DispositionType::Attachment,
@@ -191,7 +191,7 @@ impl NamedFile {
     /// image, and video content types, and `attachment` otherwise, and
     /// the filename is taken from the path provided in the `open` method
     /// after converting it to UTF-8 using.
-    /// [to_string_lossy](https://doc.rust-lang.org/std/ffi/struct.OsStr.html#method.to_string_lossy).
+    /// [`std::ffi::OsStr::to_string_lossy`]
     #[inline]
     pub fn set_content_disposition(mut self, cd: header::ContentDisposition) -> Self {
         self.content_disposition = cd;
@@ -215,24 +215,33 @@ impl NamedFile {
         self
     }
 
-    #[inline]
-    ///Specifies whether to use ETag or not.
+    /// Specifies whether to use ETag or not.
     ///
-    ///Default is true.
+    /// Default is true.
+    #[inline]
     pub fn use_etag(mut self, value: bool) -> Self {
         self.flags.set(Flags::ETAG, value);
         self
     }
 
-    #[inline]
-    ///Specifies whether to use Last-Modified or not.
+    /// Specifies whether to use Last-Modified or not.
     ///
-    ///Default is true.
+    /// Default is true.
+    #[inline]
     pub fn use_last_modified(mut self, value: bool) -> Self {
         self.flags.set(Flags::LAST_MD, value);
         self
     }
 
+    /// Specifies whether text responses should signal a UTF-8 encoding.
+    ///
+    /// Default is false (but will default to true in a future version).
+    #[inline]
+    pub fn prefer_utf8(mut self, value: bool) -> Self {
+        self.flags.set(Flags::PREFER_UTF8, value);
+        self
+    }
+
     pub(crate) fn etag(&self) -> Option<header::EntityTag> {
         // This etag format is similar to Apache's.
         self.modified.as_ref().map(|mtime| {
@@ -266,31 +275,31 @@ impl NamedFile {
     }
 
     /// Creates an `HttpResponse` with file as a streaming body.
-    pub fn into_response(self, req: &HttpRequest) -> Result<HttpResponse, Error> {
+    pub fn into_response(self, req: &HttpRequest) -> HttpResponse {
         if self.status_code != StatusCode::OK {
-            let mut resp = HttpResponse::build(self.status_code);
+            let mut res = HttpResponse::build(self.status_code);
 
-            resp.set(header::ContentType(self.content_type.clone()))
-                .if_true(self.flags.contains(Flags::CONTENT_DISPOSITION), |res| {
-                    res.header(
-                        header::CONTENT_DISPOSITION,
-                        self.content_disposition.to_string(),
-                    );
-                });
-
-            if let Some(current_encoding) = self.encoding {
-                resp.encoding(current_encoding);
+            if self.flags.contains(Flags::PREFER_UTF8) {
+                let ct = equiv_utf8_text(self.content_type.clone());
+                res.insert_header((header::CONTENT_TYPE, ct.to_string()));
+            } else {
+                res.insert_header((header::CONTENT_TYPE, self.content_type.to_string()));
             }
 
-            let reader = ChunkedReadFile {
-                size: self.md.len(),
-                offset: 0,
-                file: Some(self.file),
-                fut: None,
-                counter: 0,
-            };
+            if self.flags.contains(Flags::CONTENT_DISPOSITION) {
+                res.insert_header((
+                    header::CONTENT_DISPOSITION,
+                    self.content_disposition.to_string(),
+                ));
+            }
 
-            return Ok(resp.streaming(reader));
+            if let Some(current_encoding) = self.encoding {
+                res.encoding(current_encoding);
+            }
+
+            let reader = ChunkedReadFile::new(self.md.len(), 0, self.file);
+
+            return res.streaming(reader);
         }
 
         let etag = if self.flags.contains(Flags::ETAG) {
@@ -315,7 +324,7 @@ impl NamedFile {
             let t2: SystemTime = since.clone().into();
 
             match (t1.duration_since(UNIX_EPOCH), t2.duration_since(UNIX_EPOCH)) {
-                (Ok(t1), Ok(t2)) => t1 > t2,
+                (Ok(t1), Ok(t2)) => t1.as_secs() > t2.as_secs(),
                 _ => false,
             }
         } else {
@@ -334,7 +343,7 @@ impl NamedFile {
             let t2: SystemTime = since.clone().into();
 
             match (t1.duration_since(UNIX_EPOCH), t2.duration_since(UNIX_EPOCH)) {
-                (Ok(t1), Ok(t2)) => t1 <= t2,
+                (Ok(t1), Ok(t2)) => t1.as_secs() <= t2.as_secs(),
                 _ => false,
             }
         } else {
@@ -342,27 +351,35 @@ impl NamedFile {
         };
 
         let mut resp = HttpResponse::build(self.status_code);
-        resp.set(header::ContentType(self.content_type.clone()))
-            .if_true(self.flags.contains(Flags::CONTENT_DISPOSITION), |res| {
-                res.header(
-                    header::CONTENT_DISPOSITION,
-                    self.content_disposition.to_string(),
-                );
-            });
+
+        if self.flags.contains(Flags::PREFER_UTF8) {
+            let ct = equiv_utf8_text(self.content_type.clone());
+            resp.insert_header((header::CONTENT_TYPE, ct.to_string()));
+        } else {
+            resp.insert_header((header::CONTENT_TYPE, self.content_type.to_string()));
+        }
+
+        if self.flags.contains(Flags::CONTENT_DISPOSITION) {
+            resp.insert_header((
+                header::CONTENT_DISPOSITION,
+                self.content_disposition.to_string(),
+            ));
+        }
 
         // default compressing
         if let Some(current_encoding) = self.encoding {
             resp.encoding(current_encoding);
         }
 
-        resp.if_some(last_modified, |lm, resp| {
-            resp.set(header::LastModified(lm));
-        })
-        .if_some(etag, |etag, resp| {
-            resp.set(header::ETag(etag));
-        });
+        if let Some(lm) = last_modified {
+            resp.insert_header((header::LAST_MODIFIED, lm.to_string()));
+        }
 
-        resp.header(header::ACCEPT_RANGES, "bytes");
+        if let Some(etag) = etag {
+            resp.insert_header((header::ETAG, etag.to_string()));
+        }
+
+        resp.insert_header((header::ACCEPT_RANGES, "bytes"));
 
         let mut length = self.md.len();
         let mut offset = 0;
@@ -375,43 +392,32 @@ impl NamedFile {
                     offset = ranges[0].start;
 
                     resp.encoding(ContentEncoding::Identity);
-                    resp.header(
+                    resp.insert_header((
                         header::CONTENT_RANGE,
-                        format!(
-                            "bytes {}-{}/{}",
-                            offset,
-                            offset + length - 1,
-                            self.md.len()
-                        ),
-                    );
+                        format!("bytes {}-{}/{}", offset, offset + length - 1, self.md.len()),
+                    ));
                 } else {
-                    resp.header(header::CONTENT_RANGE, format!("bytes */{}", length));
-                    return Ok(resp.status(StatusCode::RANGE_NOT_SATISFIABLE).finish());
+                    resp.insert_header((header::CONTENT_RANGE, format!("bytes */{}", length)));
+                    return resp.status(StatusCode::RANGE_NOT_SATISFIABLE).finish();
                 };
             } else {
-                return Ok(resp.status(StatusCode::BAD_REQUEST).finish());
+                return resp.status(StatusCode::BAD_REQUEST).finish();
             };
         };
 
         if precondition_failed {
-            return Ok(resp.status(StatusCode::PRECONDITION_FAILED).finish());
+            return resp.status(StatusCode::PRECONDITION_FAILED).finish();
         } else if not_modified {
-            return Ok(resp.status(StatusCode::NOT_MODIFIED).finish());
+            return resp.status(StatusCode::NOT_MODIFIED).finish();
         }
 
-        let reader = ChunkedReadFile {
-            offset,
-            size: length,
-            file: Some(self.file),
-            fut: None,
-            counter: 0,
-        };
+        let reader = ChunkedReadFile::new(length, offset, self.file);
 
         if offset != 0 || length != self.md.len() {
             resp.status(StatusCode::PARTIAL_CONTENT);
         }
 
-        Ok(resp.body(SizedStream::new(length, reader)))
+        resp.body(SizedStream::new(length, reader))
     }
 }
 
@@ -470,10 +476,7 @@ fn none_match(etag: Option<&header::EntityTag>, req: &HttpRequest) -> bool {
 }
 
 impl Responder for NamedFile {
-    type Error = Error;
-    type Future = Ready<Result<HttpResponse, Error>>;
-
-    fn respond_to(self, req: &HttpRequest) -> Self::Future {
-        ready(self.into_response(req))
+    fn respond_to(self, req: &HttpRequest) -> HttpResponse {
+        self.into_response(req)
     }
 }
diff --git a/actix-files/src/path_buf.rs b/actix-files/src/path_buf.rs
index 2f3ae84d4..dd8e5b503 100644
--- a/actix-files/src/path_buf.rs
+++ b/actix-files/src/path_buf.rs
@@ -15,12 +15,19 @@ impl FromStr for PathBufWrap {
     type Err = UriSegmentError;
 
     fn from_str(path: &str) -> Result<Self, Self::Err> {
+        Self::parse_path(path, false)
+    }
+}
+
+impl PathBufWrap {
+    /// Parse a path, giving the choice of allowing hidden files to be considered valid segments.
+    pub fn parse_path(path: &str, hidden_files: bool) -> Result<Self, UriSegmentError> {
         let mut buf = PathBuf::new();
 
         for segment in path.split('/') {
             if segment == ".." {
                 buf.pop();
-            } else if segment.starts_with('.') {
+            } else if !hidden_files && segment.starts_with('.') {
                 return Err(UriSegmentError::BadStart('.'));
             } else if segment.starts_with('*') {
                 return Err(UriSegmentError::BadStart('*'));
@@ -96,4 +103,17 @@ mod tests {
             PathBuf::from_iter(vec!["seg2"])
         );
     }
+
+    #[test]
+    fn test_parse_path() {
+        assert_eq!(
+            PathBufWrap::parse_path("/test/.tt", false).map(|t| t.0),
+            Err(UriSegmentError::BadStart('.'))
+        );
+
+        assert_eq!(
+            PathBufWrap::parse_path("/test/.tt", true).unwrap().0,
+            PathBuf::from_iter(vec!["test", ".tt"])
+        );
+    }
 }
diff --git a/actix-files/src/range.rs b/actix-files/src/range.rs
index e891ca7ec..8d9fe9445 100644
--- a/actix-files/src/range.rs
+++ b/actix-files/src/range.rs
@@ -1,3 +1,5 @@
+use derive_more::{Display, Error};
+
 /// HTTP Range header representation.
 #[derive(Debug, Clone, Copy)]
 pub struct HttpRange {
@@ -8,91 +10,26 @@ pub struct HttpRange {
     pub length: u64,
 }
 
-const PREFIX: &str = "bytes=";
-const PREFIX_LEN: usize = 6;
+#[derive(Debug, Clone, Display, Error)]
+#[display(fmt = "Parse HTTP Range failed")]
+pub struct ParseRangeErr(#[error(not(source))] ());
 
 impl HttpRange {
     /// Parses Range HTTP header string as per RFC 2616.
     ///
     /// `header` is HTTP Range header (e.g. `bytes=bytes=0-9`).
     /// `size` is full size of response (file).
-    pub fn parse(header: &str, size: u64) -> Result<Vec<HttpRange>, ()> {
-        if header.is_empty() {
-            return Ok(Vec::new());
+    pub fn parse(header: &str, size: u64) -> Result<Vec<HttpRange>, ParseRangeErr> {
+        match http_range::HttpRange::parse(header, size) {
+            Ok(ranges) => Ok(ranges
+                .iter()
+                .map(|range| HttpRange {
+                    start: range.start,
+                    length: range.length,
+                })
+                .collect()),
+            Err(_) => Err(ParseRangeErr(())),
         }
-        if !header.starts_with(PREFIX) {
-            return Err(());
-        }
-
-        let size_sig = size as i64;
-        let mut no_overlap = false;
-
-        let all_ranges: Vec<Option<HttpRange>> = header[PREFIX_LEN..]
-            .split(',')
-            .map(|x| x.trim())
-            .filter(|x| !x.is_empty())
-            .map(|ra| {
-                let mut start_end_iter = ra.split('-');
-
-                let start_str = start_end_iter.next().ok_or(())?.trim();
-                let end_str = start_end_iter.next().ok_or(())?.trim();
-
-                if start_str.is_empty() {
-                    // If no start is specified, end specifies the
-                    // range start relative to the end of the file.
-                    let mut length: i64 = end_str.parse().map_err(|_| ())?;
-
-                    if length > size_sig {
-                        length = size_sig;
-                    }
-
-                    Ok(Some(HttpRange {
-                        start: (size_sig - length) as u64,
-                        length: length as u64,
-                    }))
-                } else {
-                    let start: i64 = start_str.parse().map_err(|_| ())?;
-
-                    if start < 0 {
-                        return Err(());
-                    }
-                    if start >= size_sig {
-                        no_overlap = true;
-                        return Ok(None);
-                    }
-
-                    let length = if end_str.is_empty() {
-                        // If no end is specified, range extends to end of the file.
-                        size_sig - start
-                    } else {
-                        let mut end: i64 = end_str.parse().map_err(|_| ())?;
-
-                        if start > end {
-                            return Err(());
-                        }
-
-                        if end >= size_sig {
-                            end = size_sig - 1;
-                        }
-
-                        end - start + 1
-                    };
-
-                    Ok(Some(HttpRange {
-                        start: start as u64,
-                        length: length as u64,
-                    }))
-                }
-            })
-            .collect::<Result<_, _>>()?;
-
-        let ranges: Vec<HttpRange> = all_ranges.into_iter().filter_map(|x| x).collect();
-
-        if no_overlap && ranges.is_empty() {
-            return Err(());
-        }
-
-        Ok(ranges)
     }
 }
 
@@ -333,8 +270,7 @@ mod tests {
                 if expected.is_empty() {
                     continue;
                 } else {
-                    assert!(
-                        false,
+                    panic!(
                         "parse({}, {}) returned error {:?}",
                         header,
                         size,
@@ -346,28 +282,24 @@ mod tests {
             let got = res.unwrap();
 
             if got.len() != expected.len() {
-                assert!(
-                    false,
+                panic!(
                     "len(parseRange({}, {})) = {}, want {}",
                     header,
                     size,
                     got.len(),
                     expected.len()
                 );
-                continue;
             }
 
             for i in 0..expected.len() {
                 if got[i].start != expected[i].start {
-                    assert!(
-                        false,
+                    panic!(
                         "parseRange({}, {})[{}].start = {}, want {}",
                         header, size, i, got[i].start, expected[i].start
                     )
                 }
                 if got[i].length != expected[i].length {
-                    assert!(
-                        false,
+                    panic!(
                         "parseRange({}, {})[{}].length = {}, want {}",
                         header, size, i, got[i].length, expected[i].length
                     )
diff --git a/actix-files/src/service.rs b/actix-files/src/service.rs
index cbf4c2d3b..14eea6ebc 100644
--- a/actix-files/src/service.rs
+++ b/actix-files/src/service.rs
@@ -1,9 +1,4 @@
-use std::{
-    fmt, io,
-    path::PathBuf,
-    rc::Rc,
-    task::{Context, Poll},
-};
+use std::{fmt, io, path::PathBuf, rc::Rc, task::Poll};
 
 use actix_service::Service;
 use actix_web::{
@@ -16,8 +11,8 @@ use actix_web::{
 use futures_util::future::{ok, Either, LocalBoxFuture, Ready};
 
 use crate::{
-    named, Directory, DirectoryRenderer, FilesError, HttpService, MimeOverride,
-    NamedFile, PathBufWrap,
+    named, Directory, DirectoryRenderer, FilesError, HttpService, MimeOverride, NamedFile,
+    PathBufWrap,
 };
 
 /// Assembled file serving service.
@@ -31,6 +26,7 @@ pub struct FilesService {
     pub(crate) mime_override: Option<Rc<MimeOverride>>,
     pub(crate) file_flags: named::Flags,
     pub(crate) guards: Option<Rc<dyn Guard>>,
+    pub(crate) hidden_files: bool,
 }
 
 type FilesServiceFuture = Either<
@@ -39,10 +35,10 @@ type FilesServiceFuture = Either<
 >;
 
 impl FilesService {
-    fn handle_err(&mut self, e: io::Error, req: ServiceRequest) -> FilesServiceFuture {
+    fn handle_err(&self, e: io::Error, req: ServiceRequest) -> FilesServiceFuture {
         log::debug!("Failed to handle {}: {}", req.path(), e);
 
-        if let Some(ref mut default) = self.default {
+        if let Some(ref default) = self.default {
             Either::Right(default.call(req))
         } else {
             Either::Left(ok(req.error_response(e)))
@@ -56,17 +52,14 @@ impl fmt::Debug for FilesService {
     }
 }
 
-impl Service for FilesService {
-    type Request = ServiceRequest;
+impl Service<ServiceRequest> for FilesService {
     type Response = ServiceResponse;
     type Error = Error;
     type Future = FilesServiceFuture;
 
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
+    actix_service::always_ready!();
 
-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
+    fn call(&self, req: ServiceRequest) -> Self::Future {
         let is_method_valid = if let Some(guard) = &self.guards {
             // execute user defined guards
             (**guard).check(req.head())
@@ -78,15 +71,16 @@ impl Service for FilesService {
         if !is_method_valid {
             return Either::Left(ok(req.into_response(
                 actix_web::HttpResponse::MethodNotAllowed()
-                    .header(header::CONTENT_TYPE, "text/plain")
+                    .insert_header(header::ContentType(mime::TEXT_PLAIN_UTF_8))
                     .body("Request did not meet this resource's requirements."),
             )));
         }
 
-        let real_path: PathBufWrap = match req.match_info().path().parse() {
-            Ok(item) => item,
-            Err(e) => return Either::Left(ok(req.error_response(e))),
-        };
+        let real_path =
+            match PathBufWrap::parse_path(req.match_info().path(), self.hidden_files) {
+                Ok(item) => item,
+                Err(e) => return Either::Left(ok(req.error_response(e))),
+            };
 
         // full file path
         let path = match self.directory.join(&real_path).canonicalize() {
@@ -101,7 +95,7 @@ impl Service for FilesService {
 
                     return Either::Left(ok(req.into_response(
                         HttpResponse::Found()
-                            .header(header::LOCATION, redirect_to)
+                            .insert_header((header::LOCATION, redirect_to))
                             .body("")
                             .into_body(),
                     )));
@@ -119,10 +113,8 @@ impl Service for FilesService {
                         named_file.flags = self.file_flags;
 
                         let (req, _) = req.into_parts();
-                        Either::Left(ok(match named_file.into_response(&req) {
-                            Ok(item) => ServiceResponse::new(req, item),
-                            Err(e) => ServiceResponse::from_err(e, req),
-                        }))
+                        let res = named_file.into_response(&req);
+                        Either::Left(ok(ServiceResponse::new(req, res)))
                     }
                     Err(e) => self.handle_err(e, req),
                 }
@@ -146,19 +138,14 @@ impl Service for FilesService {
             match NamedFile::open(path) {
                 Ok(mut named_file) => {
                     if let Some(ref mime_override) = self.mime_override {
-                        let new_disposition =
-                            mime_override(&named_file.content_type.type_());
+                        let new_disposition = mime_override(&named_file.content_type.type_());
                         named_file.content_disposition.disposition = new_disposition;
                     }
                     named_file.flags = self.file_flags;
 
                     let (req, _) = req.into_parts();
-                    match named_file.into_response(&req) {
-                        Ok(item) => {
-                            Either::Left(ok(ServiceResponse::new(req.clone(), item)))
-                        }
-                        Err(e) => Either::Left(ok(ServiceResponse::from_err(e, req))),
-                    }
+                    let res = named_file.into_response(&req);
+                    Either::Left(ok(ServiceResponse::new(req, res)))
                 }
                 Err(e) => self.handle_err(e, req),
             }
diff --git a/actix-files/tests/encoding.rs b/actix-files/tests/encoding.rs
new file mode 100644
index 000000000..d21d4f8fd
--- /dev/null
+++ b/actix-files/tests/encoding.rs
@@ -0,0 +1,38 @@
+use actix_files::Files;
+use actix_web::{
+    http::{
+        header::{self, HeaderValue},
+        StatusCode,
+    },
+    test::{self, TestRequest},
+    App,
+};
+
+#[actix_rt::test]
+async fn test_utf8_file_contents() {
+    // use default ISO-8859-1 encoding
+    let srv = test::init_service(App::new().service(Files::new("/", "./tests"))).await;
+
+    let req = TestRequest::with_uri("/utf8.txt").to_request();
+    let res = test::call_service(&srv, req).await;
+
+    assert_eq!(res.status(), StatusCode::OK);
+    assert_eq!(
+        res.headers().get(header::CONTENT_TYPE),
+        Some(&HeaderValue::from_static("text/plain")),
+    );
+
+    // prefer UTF-8 encoding
+    let srv =
+        test::init_service(App::new().service(Files::new("/", "./tests").prefer_utf8(true)))
+            .await;
+
+    let req = TestRequest::with_uri("/utf8.txt").to_request();
+    let res = test::call_service(&srv, req).await;
+
+    assert_eq!(res.status(), StatusCode::OK);
+    assert_eq!(
+        res.headers().get(header::CONTENT_TYPE),
+        Some(&HeaderValue::from_static("text/plain; charset=utf-8")),
+    );
+}
diff --git a/actix-files/tests/utf8.txt b/actix-files/tests/utf8.txt
new file mode 100644
index 000000000..d8590e2f5
--- /dev/null
+++ b/actix-files/tests/utf8.txt
@@ -0,0 +1,3 @@
+中文内容显示正确。
+
+English is OK.
diff --git a/test-server/CHANGES.md b/actix-http-test/CHANGES.md
similarity index 60%
rename from test-server/CHANGES.md
rename to actix-http-test/CHANGES.md
index 0a11e2cae..2f47d700d 100644
--- a/test-server/CHANGES.md
+++ b/actix-http-test/CHANGES.md
@@ -1,14 +1,31 @@
 # Changes
 
-## Unreleased - 2020-xx-xx
+## Unreleased - 2021-xx-xx
 
-* add ability to set address for `TestServer` [#1645]
 
+## 3.0.0-beta.2 - 2021-02-10
+* No notable changes.
+
+
+## 3.0.0-beta.1 - 2021-01-07
+* Update `bytes` to `1.0`. [#1813]
+
+[#1813]: https://github.com/actix/actix-web/pull/1813
+
+
+## 2.1.0 - 2020-11-25
+* Add ability to set address for `TestServer`. [#1645]
+* Upgrade `base64` to `0.13`.
+* Upgrade `serde_urlencoded` to `0.7`. [#1773]
+
+[#1773]: https://github.com/actix/actix-web/pull/1773
 [#1645]: https://github.com/actix/actix-web/pull/1645
 
+
 ## 2.0.0 - 2020-09-11
 * Update actix-codec and actix-utils dependencies.
 
+
 ## 2.0.0-alpha.1 - 2020-05-23
 * Update the `time` dependency to 0.2.7
 * Update `actix-connect` dependency to 2.0.0-alpha.2
@@ -18,74 +35,56 @@
 * Update `base64` dependency to 0.12
 * Update `env_logger` dependency to 0.7
 
-## [1.0.0] - 2019-12-13
-
-### Changed
-
+## 1.0.0 - 2019-12-13
 * Replaced `TestServer::start()` with `test_server()`
 
 
-## [1.0.0-alpha.3] - 2019-12-07
-
-### Changed
-
+## 1.0.0-alpha.3 - 2019-12-07
 * Migrate to `std::future`
 
 
-## [0.2.5] - 2019-09-17
-
-### Changed
-
+## 0.2.5 - 2019-09-17
 * Update serde_urlencoded to "0.6.1"
 * Increase TestServerRuntime timeouts from 500ms to 3000ms
-
-### Fixed
-
 * Do not override current `System`
 
 
-## [0.2.4] - 2019-07-18
-
+## 0.2.4 - 2019-07-18
 * Update actix-server to 0.6
 
-## [0.2.3] - 2019-07-16
 
+## 0.2.3 - 2019-07-16
 * Add `delete`, `options`, `patch` methods to `TestServerRunner`
 
-## [0.2.2] - 2019-06-16
 
+## 0.2.2 - 2019-06-16
 * Add .put() and .sput() methods
 
-## [0.2.1] - 2019-06-05
 
+## 0.2.1 - 2019-06-05
 * Add license files
 
-## [0.2.0] - 2019-05-12
 
+## 0.2.0 - 2019-05-12
 * Update awc and actix-http deps
 
-## [0.1.1] - 2019-04-24
 
+## 0.1.1 - 2019-04-24
 * Always make new connection for http client
 
 
-## [0.1.0] - 2019-04-16
-
+## 0.1.0 - 2019-04-16
 * No changes
 
 
-## [0.1.0-alpha.3] - 2019-04-02
-
+## 0.1.0-alpha.3 - 2019-04-02
 * Request functions accept path #743
 
 
-## [0.1.0-alpha.2] - 2019-03-29
-
+## 0.1.0-alpha.2 - 2019-03-29
 * Added TestServerRuntime::load_body() method
-
 * Update actix-http and awc libraries
 
 
-## [0.1.0-alpha.1] - 2019-03-28
-
+## 0.1.0-alpha.1 - 2019-03-28
 * Initial impl
diff --git a/actix-http-test/Cargo.toml b/actix-http-test/Cargo.toml
new file mode 100644
index 000000000..6dcf73637
--- /dev/null
+++ b/actix-http-test/Cargo.toml
@@ -0,0 +1,61 @@
+[package]
+name = "actix-http-test"
+version = "3.0.0-beta.2"
+authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
+description = "Various helpers for Actix applications to use during testing"
+readme = "README.md"
+keywords = ["http", "web", "framework", "async", "futures"]
+homepage = "https://actix.rs"
+repository = "https://github.com/actix/actix-web.git"
+documentation = "https://docs.rs/actix-http-test/"
+categories = ["network-programming", "asynchronous",
+              "web-programming::http-server",
+              "web-programming::websocket"]
+license = "MIT OR Apache-2.0"
+exclude = [".gitignore", ".cargo/config"]
+edition = "2018"
+
+[package.metadata.docs.rs]
+features = []
+
+[lib]
+name = "actix_http_test"
+path = "src/lib.rs"
+
+[features]
+default = []
+
+# openssl
+openssl = ["tls-openssl", "awc/openssl"]
+
+[dependencies]
+actix-service = "2.0.0-beta.4"
+actix-codec = "0.4.0-beta.1"
+actix-tls = "3.0.0-beta.3"
+actix-utils = "3.0.0-beta.2"
+actix-rt = "2"
+actix-server = "2.0.0-beta.3"
+awc = "3.0.0-beta.2"
+
+base64 = "0.13"
+bytes = "1"
+futures-core = { version = "0.3.7", default-features = false }
+http = "0.2.2"
+log = "0.4"
+socket2 = "0.3"
+serde = "1.0"
+serde_json = "1.0"
+slab = "0.4"
+serde_urlencoded = "0.7"
+time = { version = "0.2.23", default-features = false, features = ["std"] }
+tls-openssl = { version = "0.10.9", package = "openssl", optional = true }
+
+[target.'cfg(windows)'.dependencies.tls-openssl]
+version = "0.10.9"
+package = "openssl"
+features = ["vendored"]
+optional = true
+
+[dev-dependencies]
+actix-web = "4.0.0-beta.3"
+actix-http = "3.0.0-beta.3"
diff --git a/test-server/LICENSE-APACHE b/actix-http-test/LICENSE-APACHE
similarity index 100%
rename from test-server/LICENSE-APACHE
rename to actix-http-test/LICENSE-APACHE
diff --git a/test-server/LICENSE-MIT b/actix-http-test/LICENSE-MIT
similarity index 100%
rename from test-server/LICENSE-MIT
rename to actix-http-test/LICENSE-MIT
diff --git a/actix-http-test/README.md b/actix-http-test/README.md
new file mode 100644
index 000000000..66f15979d
--- /dev/null
+++ b/actix-http-test/README.md
@@ -0,0 +1,15 @@
+# actix-http-test
+
+> Various helpers for Actix applications to use during testing.
+
+[![crates.io](https://img.shields.io/crates/v/actix-http-test?label=latest)](https://crates.io/crates/actix-http-test)
+[![Documentation](https://docs.rs/actix-http-test/badge.svg?version=2.1.0)](https://docs.rs/actix-http-test/2.1.0)
+![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/actix-http-test)
+[![Dependency Status](https://deps.rs/crate/actix-http-test/2.1.0/status.svg)](https://deps.rs/crate/actix-http-test/2.1.0)
+[![Join the chat at https://gitter.im/actix/actix-web](https://badges.gitter.im/actix/actix-web.svg)](https://gitter.im/actix/actix-web?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
+## Documentation & Resources
+
+- [API Documentation](https://docs.rs/actix-http-test)
+- [Chat on Gitter](https://gitter.im/actix/actix-web)
+- Minimum Supported Rust Version (MSRV): 1.46.0
diff --git a/test-server/src/lib.rs b/actix-http-test/src/lib.rs
similarity index 85%
rename from test-server/src/lib.rs
rename to actix-http-test/src/lib.rs
index 4159c8d86..8de07c8d3 100644
--- a/test-server/src/lib.rs
+++ b/actix-http-test/src/lib.rs
@@ -1,4 +1,12 @@
 //! Various helpers for Actix applications to use during testing.
+
+#![deny(rust_2018_idioms)]
+#![doc(html_logo_url = "https://actix.rs/img/logo.png")]
+#![doc(html_favicon_url = "https://actix.rs/favicon.ico")]
+
+#[cfg(feature = "openssl")]
+extern crate tls_openssl as openssl;
+
 use std::sync::mpsc;
 use std::{net, thread, time};
 
@@ -11,8 +19,6 @@ use futures_core::stream::Stream;
 use http::Method;
 use socket2::{Domain, Protocol, Socket, Type};
 
-pub use actix_testing::*;
-
 /// Start test server
 ///
 /// `TestServer` is very simple test server that simplify process of writing
@@ -48,7 +54,7 @@ pub async fn test_server<F: ServiceFactory<TcpStream>>(factory: F) -> TestServer
     test_server_with_addr(tcp, factory).await
 }
 
-/// Start [`test server`](./fn.test_server.html) on a concrete Address
+/// Start [`test server`](test_server()) on a concrete Address
 pub async fn test_server_with_addr<F: ServiceFactory<TcpStream>>(
     tcp: net::TcpListener,
     factory: F,
@@ -57,16 +63,19 @@ pub async fn test_server_with_addr<F: ServiceFactory<TcpStream>>(
 
     // run server in separate thread
     thread::spawn(move || {
-        let sys = System::new("actix-test-server");
+        let sys = System::new();
         let local_addr = tcp.local_addr().unwrap();
 
-        Server::build()
+        let srv = Server::build()
             .listen("test", tcp, factory)?
             .workers(1)
-            .disable_signals()
-            .start();
+            .disable_signals();
+
+        sys.block_on(async {
+            srv.run();
+            tx.send((System::current(), local_addr)).unwrap();
+        });
 
-        tx.send((System::current(), local_addr)).unwrap();
         sys.run()
     });
 
@@ -76,7 +85,7 @@ pub async fn test_server_with_addr<F: ServiceFactory<TcpStream>>(
         let connector = {
             #[cfg(feature = "openssl")]
             {
-                use open_ssl::ssl::{SslConnector, SslMethod, SslVerifyMode};
+                use openssl::ssl::{SslConnector, SslMethod, SslVerifyMode};
 
                 let mut builder = SslConnector::builder(SslMethod::tls()).unwrap();
                 builder.set_verify(SslVerifyMode::NONE);
@@ -87,20 +96,17 @@ pub async fn test_server_with_addr<F: ServiceFactory<TcpStream>>(
                     .conn_lifetime(time::Duration::from_secs(0))
                     .timeout(time::Duration::from_millis(30000))
                     .ssl(builder.build())
-                    .finish()
             }
             #[cfg(not(feature = "openssl"))]
             {
                 Connector::new()
                     .conn_lifetime(time::Duration::from_secs(0))
                     .timeout(time::Duration::from_millis(30000))
-                    .finish()
             }
         };
 
         Client::builder().connector(connector).finish()
     };
-    actix_connect::start_default_resolver().await.unwrap();
 
     TestServer {
         addr,
@@ -112,8 +118,7 @@ pub async fn test_server_with_addr<F: ServiceFactory<TcpStream>>(
 /// Get first available unused address
 pub fn unused_addr() -> net::SocketAddr {
     let addr: net::SocketAddr = "127.0.0.1:0".parse().unwrap();
-    let socket =
-        Socket::new(Domain::ipv4(), Type::stream(), Some(Protocol::tcp())).unwrap();
+    let socket = Socket::new(Domain::ipv4(), Type::stream(), Some(Protocol::tcp())).unwrap();
     socket.bind(&addr.into()).unwrap();
     socket.set_reuse_address(true).unwrap();
     let tcp = socket.into_tcp_listener();
@@ -142,7 +147,7 @@ impl TestServer {
         }
     }
 
-    /// Construct test https server url
+    /// Construct test HTTPS server URL.
     pub fn surl(&self, uri: &str) -> String {
         if uri.starts_with('/') {
             format!("https://localhost:{}{}", self.addr.port(), uri)
@@ -156,7 +161,7 @@ impl TestServer {
         self.client.get(self.url(path.as_ref()).as_str())
     }
 
-    /// Create https `GET` request
+    /// Create HTTPS `GET` request
     pub fn sget<S: AsRef<str>>(&self, path: S) -> ClientRequest {
         self.client.get(self.surl(path.as_ref()).as_str())
     }
@@ -166,7 +171,7 @@ impl TestServer {
         self.client.post(self.url(path.as_ref()).as_str())
     }
 
-    /// Create https `POST` request
+    /// Create HTTPS `POST` request
     pub fn spost<S: AsRef<str>>(&self, path: S) -> ClientRequest {
         self.client.post(self.surl(path.as_ref()).as_str())
     }
@@ -176,7 +181,7 @@ impl TestServer {
         self.client.head(self.url(path.as_ref()).as_str())
     }
 
-    /// Create https `HEAD` request
+    /// Create HTTPS `HEAD` request
     pub fn shead<S: AsRef<str>>(&self, path: S) -> ClientRequest {
         self.client.head(self.surl(path.as_ref()).as_str())
     }
@@ -186,7 +191,7 @@ impl TestServer {
         self.client.put(self.url(path.as_ref()).as_str())
     }
 
-    /// Create https `PUT` request
+    /// Create HTTPS `PUT` request
     pub fn sput<S: AsRef<str>>(&self, path: S) -> ClientRequest {
         self.client.put(self.surl(path.as_ref()).as_str())
     }
@@ -196,7 +201,7 @@ impl TestServer {
         self.client.patch(self.url(path.as_ref()).as_str())
     }
 
-    /// Create https `PATCH` request
+    /// Create HTTPS `PATCH` request
     pub fn spatch<S: AsRef<str>>(&self, path: S) -> ClientRequest {
         self.client.patch(self.surl(path.as_ref()).as_str())
     }
@@ -206,7 +211,7 @@ impl TestServer {
         self.client.delete(self.url(path.as_ref()).as_str())
     }
 
-    /// Create https `DELETE` request
+    /// Create HTTPS `DELETE` request
     pub fn sdelete<S: AsRef<str>>(&self, path: S) -> ClientRequest {
         self.client.delete(self.surl(path.as_ref()).as_str())
     }
@@ -216,12 +221,12 @@ impl TestServer {
         self.client.options(self.url(path.as_ref()).as_str())
     }
 
-    /// Create https `OPTIONS` request
+    /// Create HTTPS `OPTIONS` request
     pub fn soptions<S: AsRef<str>>(&self, path: S) -> ClientRequest {
         self.client.options(self.surl(path.as_ref()).as_str())
     }
 
-    /// Connect to test http server
+    /// Connect to test HTTP server
     pub fn request<S: AsRef<str>>(&self, method: Method, path: S) -> ClientRequest {
         self.client.request(method, path.as_ref())
     }
@@ -236,26 +241,24 @@ impl TestServer {
         response.body().limit(10_485_760).await
     }
 
-    /// Connect to websocket server at a given path
+    /// Connect to WebSocket server at a given path.
     pub async fn ws_at(
         &mut self,
         path: &str,
-    ) -> Result<Framed<impl AsyncRead + AsyncWrite, ws::Codec>, awc::error::WsClientError>
-    {
+    ) -> Result<Framed<impl AsyncRead + AsyncWrite, ws::Codec>, awc::error::WsClientError> {
         let url = self.url(path);
         let connect = self.client.ws(url).connect();
         connect.await.map(|(_, framed)| framed)
     }
 
-    /// Connect to a websocket server
+    /// Connect to a WebSocket server.
     pub async fn ws(
         &mut self,
-    ) -> Result<Framed<impl AsyncRead + AsyncWrite, ws::Codec>, awc::error::WsClientError>
-    {
+    ) -> Result<Framed<impl AsyncRead + AsyncWrite, ws::Codec>, awc::error::WsClientError> {
         self.ws_at("/").await
     }
 
-    /// Stop http server
+    /// Stop HTTP server
     fn stop(&mut self) {
         self.system.stop();
     }
diff --git a/actix-http/CHANGES.md b/actix-http/CHANGES.md
index 6a98c4ca7..6ba111eb3 100644
--- a/actix-http/CHANGES.md
+++ b/actix-http/CHANGES.md
@@ -1,6 +1,133 @@
 # Changes
 
-## Unreleased - 2020-xx-xx
+## Unreleased - 2021-xx-xx
+### Changed
+* Feature `cookies` is now optional and disabled by default. [#1981]
+
+### Removed
+* re-export of `futures_channel::oneshot::Canceled` is removed from `error` mod. [#1994]
+* `ResponseError` impl for `futures_channel::oneshot::Canceled` is removed. [#1994]
+
+[#1981]: https://github.com/actix/actix-web/pull/1981
+[#1994]: https://github.com/actix/actix-web/pull/1994
+
+
+## 3.0.0-beta.3 - 2021-02-10
+* No notable changes.
+
+
+## 3.0.0-beta.2 - 2021-02-10
+### Added
+* `IntoHeaderPair` trait that allows using typed and untyped headers in the same methods. [#1869]
+* `ResponseBuilder::insert_header` method which allows using typed headers. [#1869]
+* `ResponseBuilder::append_header` method which allows using typed headers. [#1869]
+* `TestRequest::insert_header` method which allows using typed headers. [#1869]
+* `ContentEncoding` implements all necessary header traits. [#1912]
+* `HeaderMap::len_keys` has the behavior of the old `len` method. [#1964]
+* `HeaderMap::drain` as an efficient draining iterator. [#1964]
+* Implement `IntoIterator` for owned `HeaderMap`. [#1964]
+* `trust-dns` optional feature to enable `trust-dns-resolver` as client dns resolver. [#1969]
+
+### Changed
+* `ResponseBuilder::content_type` now takes an `impl IntoHeaderValue` to support using typed
+  `mime` types. [#1894]
+* Renamed `IntoHeaderValue::{try_into => try_into_value}` to avoid ambiguity with std
+  `TryInto` trait. [#1894]
+* `Extensions::insert` returns Option of replaced item. [#1904]
+* Remove `HttpResponseBuilder::json2()`. [#1903]
+* Enable `HttpResponseBuilder::json()` to receive data by value and reference. [#1903]
+* `client::error::ConnectError` Resolver variant contains `Box<dyn std::error::Error>` type. [#1905]
+* `client::ConnectorConfig` default timeout changed to 5 seconds. [#1905]
+* Simplify `BlockingError` type to a unit struct. It's now only triggered when blocking thread pool
+  is dead. [#1957]
+* `HeaderMap::len` now returns number of values instead of number of keys. [#1964]
+* `HeaderMap::insert` now returns iterator of removed values. [#1964]
+* `HeaderMap::remove` now returns iterator of removed values. [#1964]
+
+### Removed
+* `ResponseBuilder::set`; use `ResponseBuilder::insert_header`. [#1869]
+* `ResponseBuilder::set_header`; use `ResponseBuilder::insert_header`. [#1869]
+* `ResponseBuilder::header`; use `ResponseBuilder::append_header`. [#1869]
+* `TestRequest::with_hdr`; use `TestRequest::default().insert_header()`. [#1869]
+* `TestRequest::with_header`; use `TestRequest::default().insert_header()`. [#1869]
+* `actors` optional feature. [#1969]
+* `ResponseError` impl for `actix::MailboxError`. [#1969]
+
+### Documentation
+* Vastly improve docs and add examples for `HeaderMap`. [#1964]
+
+[#1869]: https://github.com/actix/actix-web/pull/1869
+[#1894]: https://github.com/actix/actix-web/pull/1894
+[#1903]: https://github.com/actix/actix-web/pull/1903
+[#1904]: https://github.com/actix/actix-web/pull/1904
+[#1905]: https://github.com/actix/actix-web/pull/1905
+[#1912]: https://github.com/actix/actix-web/pull/1912
+[#1957]: https://github.com/actix/actix-web/pull/1957
+[#1964]: https://github.com/actix/actix-web/pull/1964
+[#1969]: https://github.com/actix/actix-web/pull/1969
+
+
+## 3.0.0-beta.1 - 2021-01-07
+### Added
+* Add `Http3` to `Protocol` enum for future compatibility and also mark `#[non_exhaustive]`.
+
+### Changed
+* Update `actix-*` dependencies to tokio `1.0` based versions. [#1813]
+* Bumped `rand` to `0.8`.
+* Update `bytes` to `1.0`. [#1813]
+* Update `h2` to `0.3`. [#1813]
+* The `ws::Message::Text` enum variant now contains a `bytestring::ByteString`. [#1864]
+
+### Removed
+* Deprecated `on_connect` methods have been removed. Prefer the new
+  `on_connect_ext` technique. [#1857]
+* Remove `ResponseError` impl for `actix::actors::resolver::ResolverError`
+  due to deprecate of resolver actor. [#1813]
+* Remove `ConnectError::SslHandshakeError` and re-export of `HandshakeError`.
+  due to the removal of this type from `tokio-openssl` crate. openssl handshake 
+  error would return as `ConnectError::SslError`. [#1813]
+* Remove `actix-threadpool` dependency. Use `actix_rt::task::spawn_blocking`.
+  Due to this change `actix_threadpool::BlockingError` type is moved into 
+  `actix_http::error` module. [#1878]
+
+[#1813]: https://github.com/actix/actix-web/pull/1813
+[#1857]: https://github.com/actix/actix-web/pull/1857
+[#1864]: https://github.com/actix/actix-web/pull/1864
+[#1878]: https://github.com/actix/actix-web/pull/1878
+
+
+## 2.2.0 - 2020-11-25
+### Added
+* HttpResponse builders for 1xx status codes. [#1768]
+* `Accept::mime_precedence` and `Accept::mime_preference`. [#1793]
+* `TryFrom<u16>` and `TryFrom<f32>` for `http::header::Quality`. [#1797]
+
+### Fixed
+* Started dropping `transfer-encoding: chunked` and `Content-Length` for 1XX and 204 responses. [#1767]
+
+### Changed
+* Upgrade `serde_urlencoded` to `0.7`. [#1773]
+
+[#1773]: https://github.com/actix/actix-web/pull/1773
+[#1767]: https://github.com/actix/actix-web/pull/1767
+[#1768]: https://github.com/actix/actix-web/pull/1768
+[#1793]: https://github.com/actix/actix-web/pull/1793
+[#1797]: https://github.com/actix/actix-web/pull/1797
+
+
+## 2.1.0 - 2020-10-30
+### Added
+* Added more flexible `on_connect_ext` methods for on-connect handling. [#1754]
+
+### Changed
+* Upgrade `base64` to `0.13`. [#1744]
+* Upgrade `pin-project` to `1.0`. [#1733]
+* Deprecate `ResponseBuilder::{if_some, if_true}`. [#1760]
+
+[#1760]: https://github.com/actix/actix-web/pull/1760
+[#1754]: https://github.com/actix/actix-web/pull/1754
+[#1733]: https://github.com/actix/actix-web/pull/1733
+[#1744]: https://github.com/actix/actix-web/pull/1744
 
 
 ## 2.0.0 - 2020-09-11
@@ -13,15 +140,14 @@
 * Update actix-connect and actix-tls dependencies.
 
 
-## [2.0.0-beta.3] - 2020-08-14
-
+## 2.0.0-beta.3 - 2020-08-14
 ### Fixed
 * Memory leak of `client::pool::ConnectorPoolSupport`. [#1626]
 
 [#1626]: https://github.com/actix/actix-web/pull/1626
 
 
-## [2.0.0-beta.2] - 2020-07-21
+## 2.0.0-beta.2 - 2020-07-21
 ### Fixed
 * Potential UB in h1 decoder using uninitialized memory. [#1614]
 
@@ -32,10 +158,8 @@
 [#1615]: https://github.com/actix/actix-web/pull/1615
 
 
-## [2.0.0-beta.1] - 2020-07-11
-
+## 2.0.0-beta.1 - 2020-07-11
 ### Changed
-
 * Migrate cookie handling to `cookie` crate. [#1558]
 * Update `sha-1` to 0.9. [#1586]
 * Fix leak in client pool. [#1580]
@@ -45,33 +169,30 @@
 [#1586]: https://github.com/actix/actix-web/pull/1586
 [#1580]: https://github.com/actix/actix-web/pull/1580
 
-## [2.0.0-alpha.4] - 2020-05-21
 
+## 2.0.0-alpha.4 - 2020-05-21
 ### Changed
-
 * Bump minimum supported Rust version to 1.40
-* content_length function is removed, and you can set Content-Length by calling no_chunking function [#1439]
+* content_length function is removed, and you can set Content-Length by calling
+  no_chunking function [#1439]
 * `BodySize::Sized64` variant has been removed. `BodySize::Sized` now receives a
   `u64` instead of a `usize`.
 * Update `base64` dependency to 0.12
 
 ### Fixed
-
 * Support parsing of `SameSite=None` [#1503]
 
 [#1439]: https://github.com/actix/actix-web/pull/1439
 [#1503]: https://github.com/actix/actix-web/pull/1503
 
-## [2.0.0-alpha.3] - 2020-05-08
 
+## 2.0.0-alpha.3 - 2020-05-08
 ### Fixed
-
 * Correct spelling of ConnectError::Unresolved [#1487]
 * Fix a mistake in the encoding of websocket continuation messages wherein
   Item::FirstText and Item::FirstBinary are each encoded as the other.
 
 ### Changed
-
 * Implement `std::error::Error` for our custom errors [#1422]
 * Remove `failure` support for `ResponseError` since that crate
   will be deprecated in the near future.
@@ -79,338 +200,247 @@
 [#1422]: https://github.com/actix/actix-web/pull/1422
 [#1487]: https://github.com/actix/actix-web/pull/1487
 
-## [2.0.0-alpha.2] - 2020-03-07
 
+## 2.0.0-alpha.2 - 2020-03-07
 ### Changed
-
 * Update `actix-connect` and `actix-tls` dependency to 2.0.0-alpha.1. [#1395]
-
-* Change default initial window size and connection window size for HTTP2 to 2MB and 1MB respectively
-  to improve download speed for awc when downloading large objects. [#1394]
-
-* client::Connector accepts initial_window_size and initial_connection_window_size HTTP2 configuration. [#1394]
-
+* Change default initial window size and connection window size for HTTP2 to 2MB and 1MB
+  respectively to improve download speed for awc when downloading large objects. [#1394]
+* client::Connector accepts initial_window_size and initial_connection_window_size
+  HTTP2 configuration. [#1394]
 * client::Connector allowing to set max_http_version to limit HTTP version to be used. [#1394]
 
 [#1394]: https://github.com/actix/actix-web/pull/1394
 [#1395]: https://github.com/actix/actix-web/pull/1395
 
-## [2.0.0-alpha.1] - 2020-02-27
 
+## 2.0.0-alpha.1 - 2020-02-27
 ### Changed
-
 * Update the `time` dependency to 0.2.7.
 * Moved actors messages support from actix crate, enabled with feature `actors`.
-* Breaking change: trait MessageBody requires Unpin and accepting Pin<&mut Self> instead of &mut self in the poll_next().
+* Breaking change: trait MessageBody requires Unpin and accepting `Pin<&mut Self>` instead of
+  `&mut self` in the poll_next().
 * MessageBody is not implemented for &'static [u8] anymore.
 
 ### Fixed
-
 * Allow `SameSite=None` cookies to be sent in a response.
 
-## [1.0.1] - 2019-12-20
 
+## 1.0.1 - 2019-12-20
 ### Fixed
-
 * Poll upgrade service's readiness from HTTP service handlers
-
 * Replace brotli with brotli2 #1224
 
-## [1.0.0] - 2019-12-13
 
+## 1.0.0 - 2019-12-13
 ### Added
-
 * Add websockets continuation frame support
 
 ### Changed
-
 * Replace `flate2-xxx` features with `compress`
 
-## [1.0.0-alpha.5] - 2019-12-09
 
+## 1.0.0-alpha.5 - 2019-12-09
 ### Fixed
-
 * Check `Upgrade` service readiness before calling it
-
-* Fix buffer remaining capacity calcualtion
+* Fix buffer remaining capacity calculation
 
 ### Changed
-
 * Websockets: Ping and Pong should have binary data #1049
 
-## [1.0.0-alpha.4] - 2019-12-08
 
+## 1.0.0-alpha.4 - 2019-12-08
 ### Added
-
 * Add impl ResponseBuilder for Error
 
 ### Changed
-
 * Use rust based brotli compression library
 
-## [1.0.0-alpha.3] - 2019-12-07
-
+## 1.0.0-alpha.3 - 2019-12-07
 ### Changed
-
 * Migrate to tokio 0.2
-
 * Migrate to `std::future`
 
 
-## [0.2.11] - 2019-11-06
-
+## 0.2.11 - 2019-11-06
 ### Added
-
 * Add support for serde_json::Value to be passed as argument to ResponseBuilder.body()
-
-* Add an additional `filename*` param in the `Content-Disposition` header of `actix_files::NamedFile` to be more compatible. (#1151)
-
+* Add an additional `filename*` param in the `Content-Disposition` header of
+  `actix_files::NamedFile` to be more compatible. (#1151)
 * Allow to use `std::convert::Infallible` as `actix_http::error::Error`
 
 ### Fixed
+* To be compatible with non-English error responses, `ResponseError` rendered with `text/plain;
+  charset=utf-8` header [#1118]
 
-* To be compatible with non-English error responses, `ResponseError` rendered with `text/plain; charset=utf-8` header #1118
+[#1878]: https://github.com/actix/actix-web/pull/1878
 
 
-## [0.2.10] - 2019-09-11
-
+## 0.2.10 - 2019-09-11
 ### Added
-
-* Add support for sending HTTP requests with `Rc<RequestHead>` in addition to sending HTTP requests with `RequestHead`
+* Add support for sending HTTP requests with `Rc<RequestHead>` in addition to sending HTTP requests
+  with `RequestHead`
 
 ### Fixed
-
 * h2 will use error response #1080
-
 * on_connect result isn't added to request extensions for http2 requests #1009
 
 
-## [0.2.9] - 2019-08-13
-
+## 0.2.9 - 2019-08-13
 ### Changed
-
 * Dropped the `byteorder`-dependency in favor of `stdlib`-implementation
-
 * Update percent-encoding to 2.1
-
 * Update serde_urlencoded to 0.6.1
 
 ### Fixed
-
 * Fixed a panic in the HTTP2 handshake in client HTTP requests (#1031)
 
 
-## [0.2.8] - 2019-08-01
-
+## 0.2.8 - 2019-08-01
 ### Added
-
 * Add `rustls` support
-
 * Add `Clone` impl for `HeaderMap`
 
 ### Fixed
-
 * awc client panic #1016
-
-* Invalid response with compression middleware enabled, but compression-related features disabled #997
+* Invalid response with compression middleware enabled, but compression-related features
+  disabled #997
 
 
-## [0.2.7] - 2019-07-18
-
+## 0.2.7 - 2019-07-18
 ### Added
-
 * Add support for downcasting response errors #986
 
 
-## [0.2.6] - 2019-07-17
-
+## 0.2.6 - 2019-07-17
 ### Changed
-
 * Replace `ClonableService` with local copy
-
 * Upgrade `rand` dependency version to 0.7
 
 
-## [0.2.5] - 2019-06-28
-
+## 0.2.5 - 2019-06-28
 ### Added
-
 * Add `on-connect` callback, `HttpServiceBuilder::on_connect()` #946
 
 ### Changed
-
 * Use `encoding_rs` crate instead of unmaintained `encoding` crate
-
 * Add `Copy` and `Clone` impls for `ws::Codec`
 
 
-## [0.2.4] - 2019-06-16
-
+## 0.2.4 - 2019-06-16
 ### Fixed
-
 * Do not compress NoContent (204) responses #918
 
 
-## [0.2.3] - 2019-06-02
-
+## 0.2.3 - 2019-06-02
 ### Added
-
 * Debug impl for ResponseBuilder
-
 * From SizedStream and BodyStream for Body
 
 ### Changed
-
 * SizedStream uses u64
 
 
-## [0.2.2] - 2019-05-29
-
+## 0.2.2 - 2019-05-29
 ### Fixed
-
 * Parse incoming stream before closing stream on disconnect #868
 
 
-## [0.2.1] - 2019-05-25
-
+## 0.2.1 - 2019-05-25
 ### Fixed
-
 * Handle socket read disconnect
 
 
-## [0.2.0] - 2019-05-12
-
+## 0.2.0 - 2019-05-12
 ### Changed
-
 * Update actix-service to 0.4
-
 * Expect and upgrade services accept `ServerConfig` config.
 
 ### Deleted
-
 * `OneRequest` service
 
 
-## [0.1.5] - 2019-05-04
-
+## 0.1.5 - 2019-05-04
 ### Fixed
-
 * Clean up response extensions in response pool #817
 
 
-## [0.1.4] - 2019-04-24
-
+## 0.1.4 - 2019-04-24
 ### Added
-
 * Allow to render h1 request headers in `Camel-Case`
 
 ### Fixed
-
 * Read until eof for http/1.0 responses #771
 
 
-## [0.1.3] - 2019-04-23
-
+## 0.1.3 - 2019-04-23
 ### Fixed
-
 * Fix http client pool management
-
 * Fix http client wait queue management #794
 
 
-## [0.1.2] - 2019-04-23
-
+## 0.1.2 - 2019-04-23
 ### Fixed
-
 * Fix BorrowMutError panic in client connector #793
 
 
-## [0.1.1] - 2019-04-19
-
+## 0.1.1 - 2019-04-19
 ### Changed
-
 * Cookie::max_age() accepts value in seconds
-
 * Cookie::max_age_time() accepts value in time::Duration
-
 * Allow to specify server address for client connector
 
 
-## [0.1.0] - 2019-04-16
-
+## 0.1.0 - 2019-04-16
 ### Added
-
 * Expose peer addr via `Request::peer_addr()` and `RequestHead::peer_addr`
 
 ### Changed
-
 * `actix_http::encoding` always available
-
 * use trust-dns-resolver 0.11.0
 
 
-## [0.1.0-alpha.5] - 2019-04-12
-
+## 0.1.0-alpha.5 - 2019-04-12
 ### Added
-
 * Allow to use custom service for upgrade requests
-
 * Added `h1::SendResponse` future.
 
 ### Changed
-
 * MessageBody::length() renamed to MessageBody::size() for consistency
-
 * ws handshake verification functions take RequestHead instead of Request
 
 
-## [0.1.0-alpha.4] - 2019-04-08
-
+## 0.1.0-alpha.4 - 2019-04-08
 ### Added
-
 * Allow to use custom `Expect` handler
-
 * Add minimal `std::error::Error` impl for `Error`
 
 ### Changed
-
 * Export IntoHeaderValue
-
 * Render error and return as response body
-
-* Use thread pool for response body comression
+* Use thread pool for response body compression
 
 ### Deleted
-
 * Removed PayloadBuffer
 
 
-## [0.1.0-alpha.3] - 2019-04-02
-
+## 0.1.0-alpha.3 - 2019-04-02
 ### Added
-
 * Warn when an unsealed private cookie isn't valid UTF-8
 
 ### Fixed
-
 * Rust 1.31.0 compatibility
-
 * Preallocate read buffer for h1 codec
-
 * Detect socket disconnection during protocol selection
 
 
-## [0.1.0-alpha.2] - 2019-03-29
-
+## 0.1.0-alpha.2 - 2019-03-29
 ### Added
-
 * Added ws::Message::Nop, no-op websockets message
 
 ### Changed
-
-* Do not use thread pool for decomression if chunk size is smaller than 2048.
+* Do not use thread pool for decompression if chunk size is smaller than 2048.
 
 
-## [0.1.0-alpha.1] - 2019-03-28
-
+## 0.1.0-alpha.1 - 2019-03-28
 * Initial impl
diff --git a/actix-http/CODE_OF_CONDUCT.md b/actix-http/CODE_OF_CONDUCT.md
deleted file mode 100644
index 599b28c0d..000000000
--- a/actix-http/CODE_OF_CONDUCT.md
+++ /dev/null
@@ -1,46 +0,0 @@
-# Contributor Covenant Code of Conduct
-
-## Our Pledge
-
-In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, gender identity and expression, level of experience, nationality, personal appearance, race, religion, or sexual identity and orientation.
-
-## Our Standards
-
-Examples of behavior that contributes to creating a positive environment include:
-
-* Using welcoming and inclusive language
-* Being respectful of differing viewpoints and experiences
-* Gracefully accepting constructive criticism
-* Focusing on what is best for the community
-* Showing empathy towards other community members
-
-Examples of unacceptable behavior by participants include:
-
-* The use of sexualized language or imagery and unwelcome sexual attention or advances
-* Trolling, insulting/derogatory comments, and personal or political attacks
-* Public or private harassment
-* Publishing others' private information, such as a physical or electronic address, without explicit permission
-* Other conduct which could reasonably be considered inappropriate in a professional setting
-
-## Our Responsibilities
-
-Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.
-
-Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.
-
-## Scope
-
-This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.
-
-## Enforcement
-
-Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at fafhrd91@gmail.com. The project team will review and investigate all complaints, and will respond in a way that it deems appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
-
-Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
-
-## Attribution
-
-This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [http://contributor-covenant.org/version/1/4][version]
-
-[homepage]: http://contributor-covenant.org
-[version]: http://contributor-covenant.org/version/1/4/
diff --git a/actix-http/Cargo.toml b/actix-http/Cargo.toml
index 0bbde881d..78fb55079 100644
--- a/actix-http/Cargo.toml
+++ b/actix-http/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "actix-http"
-version = "2.0.0"
+version = "3.0.0-beta.3"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
-description = "Actix HTTP primitives"
+description = "HTTP primitives for the Actix ecosystem"
 readme = "README.md"
 keywords = ["actix", "http", "framework", "async", "futures"]
 homepage = "https://actix.rs"
@@ -15,7 +15,8 @@ license = "MIT OR Apache-2.0"
 edition = "2018"
 
 [package.metadata.docs.rs]
-features = ["openssl", "rustls", "compress", "secure-cookies", "actors"]
+# features that docs.rs will build with
+features = ["openssl", "rustls", "compress", "cookies", "secure-cookies"]
 
 [lib]
 name = "actix_http"
@@ -25,79 +26,85 @@ path = "src/lib.rs"
 default = []
 
 # openssl
-openssl = ["actix-tls/openssl", "actix-connect/openssl"]
+openssl = ["actix-tls/openssl"]
 
 # rustls support
-rustls = ["actix-tls/rustls", "actix-connect/rustls"]
+rustls = ["actix-tls/rustls"]
 
-# enable compressison support
+# enable compression support
 compress = ["flate2", "brotli2"]
 
-# support for secure cookies
-secure-cookies = ["cookie/secure"]
+# support for cookies
+cookies = ["cookie"]
 
-# support for actix Actor messages
-actors = ["actix"]
+# support for secure cookies
+secure-cookies = ["cookies", "cookie/secure"]
+
+# trust-dns as client dns resolver
+trust-dns = ["trust-dns-resolver"]
 
 [dependencies]
-actix-service = "1.0.6"
-actix-codec = "0.3.0"
-actix-connect = "2.0.0"
-actix-utils = "2.0.0"
-actix-rt = "1.0.0"
-actix-threadpool = "0.3.1"
-actix-tls = { version = "2.0.0", optional = true }
-actix = { version = "0.10.0", optional = true }
+actix-service = "2.0.0-beta.4"
+actix-codec = "0.4.0-beta.1"
+actix-utils = "3.0.0-beta.2"
+actix-rt = "2"
+actix-tls = "3.0.0-beta.2"
 
-base64 = "0.12"
+ahash = "0.7"
+base64 = "0.13"
 bitflags = "1.2"
-bytes = "0.5.3"
-cookie = { version = "0.14.1", features = ["percent-encode"] }
-copyless = "0.1.4"
-derive_more = "0.99.2"
-either = "1.5.3"
+bytes = "1"
+bytestring = "1"
+cfg-if = "1"
+cookie = { version = "0.14.1", features = ["percent-encode"], optional = true }
+derive_more = "0.99.5"
 encoding_rs = "0.8"
-futures-channel = { version = "0.3.5", default-features = false }
-futures-core = { version = "0.3.5", default-features = false }
-futures-util = { version = "0.3.5", default-features = false }
-fxhash = "0.2.1"
-h2 = "0.2.1"
-http = "0.2.0"
+futures-core = { version = "0.3.7", default-features = false, features = ["alloc"] }
+futures-util = { version = "0.3.7", default-features = false, features = ["alloc", "sink"] }
+h2 = "0.3.0"
+http = "0.2.2"
 httparse = "1.3"
-indexmap = "1.3"
 itoa = "0.4"
-lazy_static = "1.4"
 language-tags = "0.2"
+lazy_static = "1.4"
 log = "0.4"
 mime = "0.3"
 percent-encoding = "2.1"
-pin-project = "0.4.17"
-rand = "0.7"
+pin-project = "1.0.0"
+rand = "0.8"
 regex = "1.3"
 serde = "1.0"
 serde_json = "1.0"
+serde_urlencoded = "0.7"
 sha-1 = "0.9"
-slab = "0.4"
-serde_urlencoded = "0.6.1"
-time = { version = "0.2.7", default-features = false, features = ["std"] }
+smallvec = "1.6"
+time = { version = "0.2.23", default-features = false, features = ["std"] }
+tokio = { version = "1.2", features = ["sync"] }
 
 # compression
 brotli2 = { version="0.3.2", optional = true }
 flate2 = { version = "1.0.13", optional = true }
 
+trust-dns-resolver = { version = "0.20.0", optional = true }
+
 [dev-dependencies]
-actix-server = "1.0.1"
-actix-connect = { version = "2.0.0", features = ["openssl"] }
-actix-http-test = { version = "2.0.0", features = ["openssl"] }
-actix-tls = { version = "2.0.0", features = ["openssl"] }
+actix-server = "2.0.0-beta.3"
+actix-http-test = { version = "3.0.0-beta.2", features = ["openssl"] }
+actix-tls = { version = "3.0.0-beta.2", features = ["openssl"] }
 criterion = "0.3"
-env_logger = "0.7"
+env_logger = "0.8"
+rcgen = "0.8"
 serde_derive = "1.0"
-open-ssl = { version="0.10", package = "openssl" }
-rust-tls = { version="0.18", package = "rustls" }
+tls-openssl = { version = "0.10", package = "openssl" }
+tls-rustls = { version = "0.19", package = "rustls" }
+
+[target.'cfg(windows)'.dev-dependencies.tls-openssl]
+version = "0.10.9"
+package = "openssl"
+features = ["vendored"]
 
 [[bench]]
-name = "content-length"
+name = "write-camel-case"
 harness = false
 
 [[bench]]
diff --git a/actix-http/README.md b/actix-http/README.md
index 96fc54d2e..881fbc8c5 100644
--- a/actix-http/README.md
+++ b/actix-http/README.md
@@ -1,14 +1,21 @@
-# Actix http [![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web)  [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) [![crates.io](https://meritbadge.herokuapp.com/actix-http)](https://crates.io/crates/actix-http) [![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+# actix-http
 
-Actix http
+> HTTP primitives for the Actix ecosystem.
 
-## Documentation & community resources
+[![crates.io](https://img.shields.io/crates/v/actix-http?label=latest)](https://crates.io/crates/actix-http)
+[![Documentation](https://docs.rs/actix-http/badge.svg?version=3.0.0-beta.3)](https://docs.rs/actix-http/3.0.0-beta.3)
+[![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
+![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/actix-http.svg)
+<br />
+[![dependency status](https://deps.rs/crate/actix-http/3.0.0-beta.3/status.svg)](https://deps.rs/crate/actix-http/3.0.0-beta.3)
+[![Download](https://img.shields.io/crates/d/actix-http.svg)](https://crates.io/crates/actix-http)
+[![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
-* [User Guide](https://actix.rs/docs/)
-* [API Documentation](https://docs.rs/actix-http/)
-* [Chat on gitter](https://gitter.im/actix/actix)
-* Cargo package: [actix-http](https://crates.io/crates/actix-http)
-* Minimum supported Rust version: 1.40 or later
+## Documentation & Resources
+
+- [API Documentation](https://docs.rs/actix-http)
+- [Chat on Gitter](https://gitter.im/actix/actix-web)
+- Minimum Supported Rust Version (MSRV): 1.46.0
 
 ## Example
 
diff --git a/actix-http/benches/content-length.rs b/actix-http/benches/content-length.rs
deleted file mode 100644
index 18a55a33b..000000000
--- a/actix-http/benches/content-length.rs
+++ /dev/null
@@ -1,291 +0,0 @@
-use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
-
-use bytes::BytesMut;
-
-// benchmark sending all requests at the same time
-fn bench_write_content_length(c: &mut Criterion) {
-    let mut group = c.benchmark_group("write_content_length");
-
-    let sizes = [
-        0, 1, 11, 83, 101, 653, 1001, 6323, 10001, 56329, 100001, 123456, 98724245,
-        4294967202,
-    ];
-
-    for i in sizes.iter() {
-        group.bench_with_input(BenchmarkId::new("Original (unsafe)", i), i, |b, &i| {
-            b.iter(|| {
-                let mut b = BytesMut::with_capacity(35);
-                _original::write_content_length(i, &mut b)
-            })
-        });
-
-        group.bench_with_input(BenchmarkId::new("New (safe)", i), i, |b, &i| {
-            b.iter(|| {
-                let mut b = BytesMut::with_capacity(35);
-                _new::write_content_length(i, &mut b)
-            })
-        });
-
-        group.bench_with_input(BenchmarkId::new("itoa", i), i, |b, &i| {
-            b.iter(|| {
-                let mut b = BytesMut::with_capacity(35);
-                _itoa::write_content_length(i, &mut b)
-            })
-        });
-    }
-
-    group.finish();
-}
-
-criterion_group!(benches, bench_write_content_length);
-criterion_main!(benches);
-
-mod _itoa {
-    use bytes::{BufMut, BytesMut};
-
-    pub fn write_content_length(n: usize, bytes: &mut BytesMut) {
-        if n == 0 {
-            bytes.put_slice(b"\r\ncontent-length: 0\r\n");
-            return;
-        }
-
-        let mut buf = itoa::Buffer::new();
-
-        bytes.put_slice(b"\r\ncontent-length: ");
-        bytes.put_slice(buf.format(n).as_bytes());
-        bytes.put_slice(b"\r\n");
-    }
-}
-
-mod _new {
-    use bytes::{BufMut, BytesMut};
-
-    const DIGITS_START: u8 = b'0';
-
-    /// NOTE: bytes object has to contain enough space
-    pub fn write_content_length(n: usize, bytes: &mut BytesMut) {
-        if n == 0 {
-            bytes.put_slice(b"\r\ncontent-length: 0\r\n");
-            return;
-        }
-
-        bytes.put_slice(b"\r\ncontent-length: ");
-
-        if n < 10 {
-            bytes.put_u8(DIGITS_START + (n as u8));
-        } else if n < 100 {
-            let n = n as u8;
-
-            let d10 = n / 10;
-            let d1 = n % 10;
-
-            bytes.put_u8(DIGITS_START + d10);
-            bytes.put_u8(DIGITS_START + d1);
-        } else if n < 1000 {
-            let n = n as u16;
-
-            let d100 = (n / 100) as u8;
-            let d10 = ((n / 10) % 10) as u8;
-            let d1 = (n % 10) as u8;
-
-            bytes.put_u8(DIGITS_START + d100);
-            bytes.put_u8(DIGITS_START + d10);
-            bytes.put_u8(DIGITS_START + d1);
-        } else if n < 10_000 {
-            let n = n as u16;
-
-            let d1000 = (n / 1000) as u8;
-            let d100 = ((n / 100) % 10) as u8;
-            let d10 = ((n / 10) % 10) as u8;
-            let d1 = (n % 10) as u8;
-
-            bytes.put_u8(DIGITS_START + d1000);
-            bytes.put_u8(DIGITS_START + d100);
-            bytes.put_u8(DIGITS_START + d10);
-            bytes.put_u8(DIGITS_START + d1);
-        } else if n < 100_000 {
-            let n = n as u32;
-
-            let d10000 = (n / 10000) as u8;
-            let d1000 = ((n / 1000) % 10) as u8;
-            let d100 = ((n / 100) % 10) as u8;
-            let d10 = ((n / 10) % 10) as u8;
-            let d1 = (n % 10) as u8;
-
-            bytes.put_u8(DIGITS_START + d10000);
-            bytes.put_u8(DIGITS_START + d1000);
-            bytes.put_u8(DIGITS_START + d100);
-            bytes.put_u8(DIGITS_START + d10);
-            bytes.put_u8(DIGITS_START + d1);
-        } else if n < 1_000_000 {
-            let n = n as u32;
-
-            let d100000 = (n / 100000) as u8;
-            let d10000 = ((n / 10000) % 10) as u8;
-            let d1000 = ((n / 1000) % 10) as u8;
-            let d100 = ((n / 100) % 10) as u8;
-            let d10 = ((n / 10) % 10) as u8;
-            let d1 = (n % 10) as u8;
-
-            bytes.put_u8(DIGITS_START + d100000);
-            bytes.put_u8(DIGITS_START + d10000);
-            bytes.put_u8(DIGITS_START + d1000);
-            bytes.put_u8(DIGITS_START + d100);
-            bytes.put_u8(DIGITS_START + d10);
-            bytes.put_u8(DIGITS_START + d1);
-        } else {
-            write_usize(n, bytes);
-        }
-
-        bytes.put_slice(b"\r\n");
-    }
-
-    fn write_usize(n: usize, bytes: &mut BytesMut) {
-        let mut n = n;
-
-        // 20 chars is max length of a usize (2^64)
-        // digits will be added to the buffer from lsd to msd
-        let mut buf = BytesMut::with_capacity(20);
-
-        while n > 9 {
-            // "pop" the least-significant digit
-            let lsd = (n % 10) as u8;
-
-            // remove the lsd from n
-            n = n / 10;
-
-            buf.put_u8(DIGITS_START + lsd);
-        }
-
-        // put msd to result buffer
-        bytes.put_u8(DIGITS_START + (n as u8));
-
-        // put, in reverse (msd to lsd), remaining digits to buffer
-        for i in (0..buf.len()).rev() {
-            bytes.put_u8(buf[i]);
-        }
-    }
-}
-
-mod _original {
-    use std::{mem, ptr, slice};
-
-    use bytes::{BufMut, BytesMut};
-
-    const DEC_DIGITS_LUT: &[u8] = b"0001020304050607080910111213141516171819\
-          2021222324252627282930313233343536373839\
-          4041424344454647484950515253545556575859\
-          6061626364656667686970717273747576777879\
-          8081828384858687888990919293949596979899";
-
-    /// NOTE: bytes object has to contain enough space
-    pub fn write_content_length(mut n: usize, bytes: &mut BytesMut) {
-        if n < 10 {
-            let mut buf: [u8; 21] = [
-                b'\r', b'\n', b'c', b'o', b'n', b't', b'e', b'n', b't', b'-', b'l',
-                b'e', b'n', b'g', b't', b'h', b':', b' ', b'0', b'\r', b'\n',
-            ];
-            buf[18] = (n as u8) + b'0';
-            bytes.put_slice(&buf);
-        } else if n < 100 {
-            let mut buf: [u8; 22] = [
-                b'\r', b'\n', b'c', b'o', b'n', b't', b'e', b'n', b't', b'-', b'l',
-                b'e', b'n', b'g', b't', b'h', b':', b' ', b'0', b'0', b'\r', b'\n',
-            ];
-            let d1 = n << 1;
-            unsafe {
-                ptr::copy_nonoverlapping(
-                    DEC_DIGITS_LUT.as_ptr().add(d1),
-                    buf.as_mut_ptr().offset(18),
-                    2,
-                );
-            }
-            bytes.put_slice(&buf);
-        } else if n < 1000 {
-            let mut buf: [u8; 23] = [
-                b'\r', b'\n', b'c', b'o', b'n', b't', b'e', b'n', b't', b'-', b'l',
-                b'e', b'n', b'g', b't', b'h', b':', b' ', b'0', b'0', b'0', b'\r',
-                b'\n',
-            ];
-            // decode 2 more chars, if > 2 chars
-            let d1 = (n % 100) << 1;
-            n /= 100;
-            unsafe {
-                ptr::copy_nonoverlapping(
-                    DEC_DIGITS_LUT.as_ptr().add(d1),
-                    buf.as_mut_ptr().offset(19),
-                    2,
-                )
-            };
-
-            // decode last 1
-            buf[18] = (n as u8) + b'0';
-
-            bytes.put_slice(&buf);
-        } else {
-            bytes.put_slice(b"\r\ncontent-length: ");
-            convert_usize(n, bytes);
-        }
-    }
-
-    pub(crate) fn convert_usize(mut n: usize, bytes: &mut BytesMut) {
-        let mut curr: isize = 39;
-        let mut buf: [u8; 41] = unsafe { mem::MaybeUninit::uninit().assume_init() };
-        buf[39] = b'\r';
-        buf[40] = b'\n';
-        let buf_ptr = buf.as_mut_ptr();
-        let lut_ptr = DEC_DIGITS_LUT.as_ptr();
-
-        // eagerly decode 4 characters at a time
-        while n >= 10_000 {
-            let rem = (n % 10_000) as isize;
-            n /= 10_000;
-
-            let d1 = (rem / 100) << 1;
-            let d2 = (rem % 100) << 1;
-            curr -= 4;
-            unsafe {
-                ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
-                ptr::copy_nonoverlapping(
-                    lut_ptr.offset(d2),
-                    buf_ptr.offset(curr + 2),
-                    2,
-                );
-            }
-        }
-
-        // if we reach here numbers are <= 9999, so at most 4 chars long
-        let mut n = n as isize; // possibly reduce 64bit math
-
-        // decode 2 more chars, if > 2 chars
-        if n >= 100 {
-            let d1 = (n % 100) << 1;
-            n /= 100;
-            curr -= 2;
-            unsafe {
-                ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
-            }
-        }
-
-        // decode last 1 or 2 chars
-        if n < 10 {
-            curr -= 1;
-            unsafe {
-                *buf_ptr.offset(curr) = (n as u8) + b'0';
-            }
-        } else {
-            let d1 = n << 1;
-            curr -= 2;
-            unsafe {
-                ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
-            }
-        }
-
-        unsafe {
-            bytes.extend_from_slice(slice::from_raw_parts(
-                buf_ptr.offset(curr),
-                41 - curr as usize,
-            ));
-        }
-    }
-}
diff --git a/actix-http/benches/status-line.rs b/actix-http/benches/status-line.rs
index 51f840f89..f62d18ed8 100644
--- a/actix-http/benches/status-line.rs
+++ b/actix-http/benches/status-line.rs
@@ -176,7 +176,7 @@ mod _original {
                 buf[5] = b'0';
                 buf[7] = b'9';
             }
-            _ => (),
+            _ => {}
         }
 
         let mut curr: isize = 12;
diff --git a/actix-http/benches/write-camel-case.rs b/actix-http/benches/write-camel-case.rs
new file mode 100644
index 000000000..fa4930eb9
--- /dev/null
+++ b/actix-http/benches/write-camel-case.rs
@@ -0,0 +1,89 @@
+use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
+
+fn bench_write_camel_case(c: &mut Criterion) {
+    let mut group = c.benchmark_group("write_camel_case");
+
+    let names = ["connection", "Transfer-Encoding", "transfer-encoding"];
+
+    for &i in &names {
+        let bts = i.as_bytes();
+
+        group.bench_with_input(BenchmarkId::new("Original", i), bts, |b, bts| {
+            b.iter(|| {
+                let mut buf = black_box([0; 24]);
+                _original::write_camel_case(black_box(bts), &mut buf)
+            });
+        });
+
+        group.bench_with_input(BenchmarkId::new("New", i), bts, |b, bts| {
+            b.iter(|| {
+                let mut buf = black_box([0; 24]);
+                _new::write_camel_case(black_box(bts), &mut buf)
+            });
+        });
+    }
+
+    group.finish();
+}
+
+criterion_group!(benches, bench_write_camel_case);
+criterion_main!(benches);
+
+mod _new {
+    pub fn write_camel_case(value: &[u8], buffer: &mut [u8]) {
+        // first copy entire (potentially wrong) slice to output
+        buffer[..value.len()].copy_from_slice(value);
+
+        let mut iter = value.iter();
+
+        // first character should be uppercase
+        if let Some(c @ b'a'..=b'z') = iter.next() {
+            buffer[0] = c & 0b1101_1111;
+        }
+
+        // track 1 ahead of the current position since that's the location being assigned to
+        let mut index = 2;
+
+        // remaining characters after hyphens should also be uppercase
+        while let Some(&c) = iter.next() {
+            if c == b'-' {
+                // advance iter by one and uppercase if needed
+                if let Some(c @ b'a'..=b'z') = iter.next() {
+                    buffer[index] = c & 0b1101_1111;
+                }
+            }
+
+            index += 1;
+        }
+    }
+}
+
+mod _original {
+    pub fn write_camel_case(value: &[u8], buffer: &mut [u8]) {
+        let mut index = 0;
+        let key = value;
+        let mut key_iter = key.iter();
+
+        if let Some(c) = key_iter.next() {
+            if *c >= b'a' && *c <= b'z' {
+                buffer[index] = *c ^ b' ';
+                index += 1;
+            }
+        } else {
+            return;
+        }
+
+        while let Some(c) = key_iter.next() {
+            buffer[index] = *c;
+            index += 1;
+            if *c == b'-' {
+                if let Some(c) = key_iter.next() {
+                    if *c >= b'a' && *c <= b'z' {
+                        buffer[index] = *c ^ b' ';
+                        index += 1;
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/actix-http/examples/echo.rs b/actix-http/examples/echo.rs
index beb1cce2c..90d768cbe 100644
--- a/actix-http/examples/echo.rs
+++ b/actix-http/examples/echo.rs
@@ -26,7 +26,10 @@ async fn main() -> io::Result<()> {
                     info!("request body: {:?}", body);
                     Ok::<_, Error>(
                         Response::Ok()
-                            .header("x-head", HeaderValue::from_static("dummy value!"))
+                            .insert_header((
+                                "x-head",
+                                HeaderValue::from_static("dummy value!"),
+                            ))
                             .body(body),
                     )
                 })
diff --git a/actix-http/examples/echo2.rs b/actix-http/examples/echo2.rs
index 5b7e504d3..bc932ce8f 100644
--- a/actix-http/examples/echo2.rs
+++ b/actix-http/examples/echo2.rs
@@ -15,7 +15,7 @@ async fn handle_request(mut req: Request) -> Result<Response, Error> {
 
     info!("request body: {:?}", body);
     Ok(Response::Ok()
-        .header("x-head", HeaderValue::from_static("dummy value!"))
+        .insert_header(("x-head", HeaderValue::from_static("dummy value!")))
         .body(body))
 }
 
diff --git a/actix-http/examples/hello-world.rs b/actix-http/examples/hello-world.rs
index d6477b152..a84e9aac6 100644
--- a/actix-http/examples/hello-world.rs
+++ b/actix-http/examples/hello-world.rs
@@ -19,7 +19,10 @@ async fn main() -> io::Result<()> {
                 .finish(|_req| {
                     info!("{:?}", _req);
                     let mut res = Response::Ok();
-                    res.header("x-head", HeaderValue::from_static("dummy value!"));
+                    res.insert_header((
+                        "x-head",
+                        HeaderValue::from_static("dummy value!"),
+                    ));
                     future::ok::<_, ()>(res.body("Hello world!"))
                 })
                 .tcp()
diff --git a/actix-http/src/body.rs b/actix-http/src/body.rs
deleted file mode 100644
index c5d831c45..000000000
--- a/actix-http/src/body.rs
+++ /dev/null
@@ -1,723 +0,0 @@
-use std::marker::PhantomData;
-use std::pin::Pin;
-use std::task::{Context, Poll};
-use std::{fmt, mem};
-
-use bytes::{Bytes, BytesMut};
-use futures_core::Stream;
-use futures_util::ready;
-use pin_project::pin_project;
-
-use crate::error::Error;
-
-#[derive(Debug, PartialEq, Copy, Clone)]
-/// Body size hint
-pub enum BodySize {
-    None,
-    Empty,
-    Sized(u64),
-    Stream,
-}
-
-impl BodySize {
-    pub fn is_eof(&self) -> bool {
-        matches!(self, BodySize::None | BodySize::Empty | BodySize::Sized(0))
-    }
-}
-
-/// Type that provides this trait can be streamed to a peer.
-pub trait MessageBody {
-    fn size(&self) -> BodySize;
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>>;
-
-    downcast_get_type_id!();
-}
-
-downcast!(MessageBody);
-
-impl MessageBody for () {
-    fn size(&self) -> BodySize {
-        BodySize::Empty
-    }
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        _: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        Poll::Ready(None)
-    }
-}
-
-impl<T: MessageBody + Unpin> MessageBody for Box<T> {
-    fn size(&self) -> BodySize {
-        self.as_ref().size()
-    }
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        Pin::new(self.get_mut().as_mut()).poll_next(cx)
-    }
-}
-
-#[pin_project(project = ResponseBodyProj)]
-pub enum ResponseBody<B> {
-    Body(#[pin] B),
-    Other(#[pin] Body),
-}
-
-impl ResponseBody<Body> {
-    pub fn into_body<B>(self) -> ResponseBody<B> {
-        match self {
-            ResponseBody::Body(b) => ResponseBody::Other(b),
-            ResponseBody::Other(b) => ResponseBody::Other(b),
-        }
-    }
-}
-
-impl<B> ResponseBody<B> {
-    pub fn take_body(&mut self) -> ResponseBody<B> {
-        std::mem::replace(self, ResponseBody::Other(Body::None))
-    }
-}
-
-impl<B: MessageBody> ResponseBody<B> {
-    pub fn as_ref(&self) -> Option<&B> {
-        if let ResponseBody::Body(ref b) = self {
-            Some(b)
-        } else {
-            None
-        }
-    }
-}
-
-impl<B: MessageBody> MessageBody for ResponseBody<B> {
-    fn size(&self) -> BodySize {
-        match self {
-            ResponseBody::Body(ref body) => body.size(),
-            ResponseBody::Other(ref body) => body.size(),
-        }
-    }
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        match self.project() {
-            ResponseBodyProj::Body(body) => body.poll_next(cx),
-            ResponseBodyProj::Other(body) => body.poll_next(cx),
-        }
-    }
-}
-
-impl<B: MessageBody> Stream for ResponseBody<B> {
-    type Item = Result<Bytes, Error>;
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
-        match self.project() {
-            ResponseBodyProj::Body(body) => body.poll_next(cx),
-            ResponseBodyProj::Other(body) => body.poll_next(cx),
-        }
-    }
-}
-
-#[pin_project(project = BodyProj)]
-/// Represents various types of http message body.
-pub enum Body {
-    /// Empty response. `Content-Length` header is not set.
-    None,
-    /// Zero sized response body. `Content-Length` header is set to `0`.
-    Empty,
-    /// Specific response body.
-    Bytes(Bytes),
-    /// Generic message body.
-    Message(Box<dyn MessageBody + Unpin>),
-}
-
-impl Body {
-    /// Create body from slice (copy)
-    pub fn from_slice(s: &[u8]) -> Body {
-        Body::Bytes(Bytes::copy_from_slice(s))
-    }
-
-    /// Create body from generic message body.
-    pub fn from_message<B: MessageBody + Unpin + 'static>(body: B) -> Body {
-        Body::Message(Box::new(body))
-    }
-}
-
-impl MessageBody for Body {
-    fn size(&self) -> BodySize {
-        match self {
-            Body::None => BodySize::None,
-            Body::Empty => BodySize::Empty,
-            Body::Bytes(ref bin) => BodySize::Sized(bin.len() as u64),
-            Body::Message(ref body) => body.size(),
-        }
-    }
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        match self.project() {
-            BodyProj::None => Poll::Ready(None),
-            BodyProj::Empty => Poll::Ready(None),
-            BodyProj::Bytes(ref mut bin) => {
-                let len = bin.len();
-                if len == 0 {
-                    Poll::Ready(None)
-                } else {
-                    Poll::Ready(Some(Ok(mem::take(bin))))
-                }
-            }
-            BodyProj::Message(ref mut body) => Pin::new(body.as_mut()).poll_next(cx),
-        }
-    }
-}
-
-impl PartialEq for Body {
-    fn eq(&self, other: &Body) -> bool {
-        match *self {
-            Body::None => matches!(*other, Body::None),
-            Body::Empty => matches!(*other, Body::Empty),
-            Body::Bytes(ref b) => match *other {
-                Body::Bytes(ref b2) => b == b2,
-                _ => false,
-            },
-            Body::Message(_) => false,
-        }
-    }
-}
-
-impl fmt::Debug for Body {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match *self {
-            Body::None => write!(f, "Body::None"),
-            Body::Empty => write!(f, "Body::Empty"),
-            Body::Bytes(ref b) => write!(f, "Body::Bytes({:?})", b),
-            Body::Message(_) => write!(f, "Body::Message(_)"),
-        }
-    }
-}
-
-impl From<&'static str> for Body {
-    fn from(s: &'static str) -> Body {
-        Body::Bytes(Bytes::from_static(s.as_ref()))
-    }
-}
-
-impl From<&'static [u8]> for Body {
-    fn from(s: &'static [u8]) -> Body {
-        Body::Bytes(Bytes::from_static(s))
-    }
-}
-
-impl From<Vec<u8>> for Body {
-    fn from(vec: Vec<u8>) -> Body {
-        Body::Bytes(Bytes::from(vec))
-    }
-}
-
-impl From<String> for Body {
-    fn from(s: String) -> Body {
-        s.into_bytes().into()
-    }
-}
-
-impl<'a> From<&'a String> for Body {
-    fn from(s: &'a String) -> Body {
-        Body::Bytes(Bytes::copy_from_slice(AsRef::<[u8]>::as_ref(&s)))
-    }
-}
-
-impl From<Bytes> for Body {
-    fn from(s: Bytes) -> Body {
-        Body::Bytes(s)
-    }
-}
-
-impl From<BytesMut> for Body {
-    fn from(s: BytesMut) -> Body {
-        Body::Bytes(s.freeze())
-    }
-}
-
-impl From<serde_json::Value> for Body {
-    fn from(v: serde_json::Value) -> Body {
-        Body::Bytes(v.to_string().into())
-    }
-}
-
-impl<S> From<SizedStream<S>> for Body
-where
-    S: Stream<Item = Result<Bytes, Error>> + Unpin + 'static,
-{
-    fn from(s: SizedStream<S>) -> Body {
-        Body::from_message(s)
-    }
-}
-
-impl<S, E> From<BodyStream<S, E>> for Body
-where
-    S: Stream<Item = Result<Bytes, E>> + Unpin + 'static,
-    E: Into<Error> + 'static,
-{
-    fn from(s: BodyStream<S, E>) -> Body {
-        Body::from_message(s)
-    }
-}
-
-impl MessageBody for Bytes {
-    fn size(&self) -> BodySize {
-        BodySize::Sized(self.len() as u64)
-    }
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        _: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        if self.is_empty() {
-            Poll::Ready(None)
-        } else {
-            Poll::Ready(Some(Ok(mem::take(self.get_mut()))))
-        }
-    }
-}
-
-impl MessageBody for BytesMut {
-    fn size(&self) -> BodySize {
-        BodySize::Sized(self.len() as u64)
-    }
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        _: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        if self.is_empty() {
-            Poll::Ready(None)
-        } else {
-            Poll::Ready(Some(Ok(mem::take(self.get_mut()).freeze())))
-        }
-    }
-}
-
-impl MessageBody for &'static str {
-    fn size(&self) -> BodySize {
-        BodySize::Sized(self.len() as u64)
-    }
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        _: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        if self.is_empty() {
-            Poll::Ready(None)
-        } else {
-            Poll::Ready(Some(Ok(Bytes::from_static(
-                mem::take(self.get_mut()).as_ref(),
-            ))))
-        }
-    }
-}
-
-impl MessageBody for Vec<u8> {
-    fn size(&self) -> BodySize {
-        BodySize::Sized(self.len() as u64)
-    }
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        _: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        if self.is_empty() {
-            Poll::Ready(None)
-        } else {
-            Poll::Ready(Some(Ok(Bytes::from(mem::take(self.get_mut())))))
-        }
-    }
-}
-
-impl MessageBody for String {
-    fn size(&self) -> BodySize {
-        BodySize::Sized(self.len() as u64)
-    }
-
-    fn poll_next(
-        self: Pin<&mut Self>,
-        _: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        if self.is_empty() {
-            Poll::Ready(None)
-        } else {
-            Poll::Ready(Some(Ok(Bytes::from(
-                mem::take(self.get_mut()).into_bytes(),
-            ))))
-        }
-    }
-}
-
-/// Type represent streaming body.
-/// Response does not contain `content-length` header and appropriate transfer encoding is used.
-#[pin_project]
-pub struct BodyStream<S: Unpin, E> {
-    #[pin]
-    stream: S,
-    _t: PhantomData<E>,
-}
-
-impl<S, E> BodyStream<S, E>
-where
-    S: Stream<Item = Result<Bytes, E>> + Unpin,
-    E: Into<Error>,
-{
-    pub fn new(stream: S) -> Self {
-        BodyStream {
-            stream,
-            _t: PhantomData,
-        }
-    }
-}
-
-impl<S, E> MessageBody for BodyStream<S, E>
-where
-    S: Stream<Item = Result<Bytes, E>> + Unpin,
-    E: Into<Error>,
-{
-    fn size(&self) -> BodySize {
-        BodySize::Stream
-    }
-
-    /// Attempts to pull out the next value of the underlying [`Stream`].
-    ///
-    /// Empty values are skipped to prevent [`BodyStream`]'s transmission being
-    /// ended on a zero-length chunk, but rather proceed until the underlying
-    /// [`Stream`] ends.
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        let mut stream = self.project().stream;
-        loop {
-            let stream = stream.as_mut();
-            return Poll::Ready(match ready!(stream.poll_next(cx)) {
-                Some(Ok(ref bytes)) if bytes.is_empty() => continue,
-                opt => opt.map(|res| res.map_err(Into::into)),
-            });
-        }
-    }
-}
-
-/// Type represent streaming body. This body implementation should be used
-/// if total size of stream is known. Data get sent as is without using transfer encoding.
-#[pin_project]
-pub struct SizedStream<S: Unpin> {
-    size: u64,
-    #[pin]
-    stream: S,
-}
-
-impl<S> SizedStream<S>
-where
-    S: Stream<Item = Result<Bytes, Error>> + Unpin,
-{
-    pub fn new(size: u64, stream: S) -> Self {
-        SizedStream { size, stream }
-    }
-}
-
-impl<S> MessageBody for SizedStream<S>
-where
-    S: Stream<Item = Result<Bytes, Error>> + Unpin,
-{
-    fn size(&self) -> BodySize {
-        BodySize::Sized(self.size as u64)
-    }
-
-    /// Attempts to pull out the next value of the underlying [`Stream`].
-    ///
-    /// Empty values are skipped to prevent [`SizedStream`]'s transmission being
-    /// ended on a zero-length chunk, but rather proceed until the underlying
-    /// [`Stream`] ends.
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Result<Bytes, Error>>> {
-        let mut stream: Pin<&mut S> = self.project().stream;
-        loop {
-            let stream = stream.as_mut();
-            return Poll::Ready(match ready!(stream.poll_next(cx)) {
-                Some(Ok(ref bytes)) if bytes.is_empty() => continue,
-                val => val,
-            });
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use futures_util::future::poll_fn;
-    use futures_util::pin_mut;
-    use futures_util::stream;
-
-    impl Body {
-        pub(crate) fn get_ref(&self) -> &[u8] {
-            match *self {
-                Body::Bytes(ref bin) => &bin,
-                _ => panic!(),
-            }
-        }
-    }
-
-    impl ResponseBody<Body> {
-        pub(crate) fn get_ref(&self) -> &[u8] {
-            match *self {
-                ResponseBody::Body(ref b) => b.get_ref(),
-                ResponseBody::Other(ref b) => b.get_ref(),
-            }
-        }
-    }
-
-    #[actix_rt::test]
-    async fn test_static_str() {
-        assert_eq!(Body::from("").size(), BodySize::Sized(0));
-        assert_eq!(Body::from("test").size(), BodySize::Sized(4));
-        assert_eq!(Body::from("test").get_ref(), b"test");
-
-        assert_eq!("test".size(), BodySize::Sized(4));
-        assert_eq!(
-            poll_fn(|cx| Pin::new(&mut "test").poll_next(cx))
-                .await
-                .unwrap()
-                .ok(),
-            Some(Bytes::from("test"))
-        );
-    }
-
-    #[actix_rt::test]
-    async fn test_static_bytes() {
-        assert_eq!(Body::from(b"test".as_ref()).size(), BodySize::Sized(4));
-        assert_eq!(Body::from(b"test".as_ref()).get_ref(), b"test");
-        assert_eq!(
-            Body::from_slice(b"test".as_ref()).size(),
-            BodySize::Sized(4)
-        );
-        assert_eq!(Body::from_slice(b"test".as_ref()).get_ref(), b"test");
-        let sb = Bytes::from(&b"test"[..]);
-        pin_mut!(sb);
-
-        assert_eq!(sb.size(), BodySize::Sized(4));
-        assert_eq!(
-            poll_fn(|cx| sb.as_mut().poll_next(cx)).await.unwrap().ok(),
-            Some(Bytes::from("test"))
-        );
-    }
-
-    #[actix_rt::test]
-    async fn test_vec() {
-        assert_eq!(Body::from(Vec::from("test")).size(), BodySize::Sized(4));
-        assert_eq!(Body::from(Vec::from("test")).get_ref(), b"test");
-        let test_vec = Vec::from("test");
-        pin_mut!(test_vec);
-
-        assert_eq!(test_vec.size(), BodySize::Sized(4));
-        assert_eq!(
-            poll_fn(|cx| test_vec.as_mut().poll_next(cx))
-                .await
-                .unwrap()
-                .ok(),
-            Some(Bytes::from("test"))
-        );
-    }
-
-    #[actix_rt::test]
-    async fn test_bytes() {
-        let b = Bytes::from("test");
-        assert_eq!(Body::from(b.clone()).size(), BodySize::Sized(4));
-        assert_eq!(Body::from(b.clone()).get_ref(), b"test");
-        pin_mut!(b);
-
-        assert_eq!(b.size(), BodySize::Sized(4));
-        assert_eq!(
-            poll_fn(|cx| b.as_mut().poll_next(cx)).await.unwrap().ok(),
-            Some(Bytes::from("test"))
-        );
-    }
-
-    #[actix_rt::test]
-    async fn test_bytes_mut() {
-        let b = BytesMut::from("test");
-        assert_eq!(Body::from(b.clone()).size(), BodySize::Sized(4));
-        assert_eq!(Body::from(b.clone()).get_ref(), b"test");
-        pin_mut!(b);
-
-        assert_eq!(b.size(), BodySize::Sized(4));
-        assert_eq!(
-            poll_fn(|cx| b.as_mut().poll_next(cx)).await.unwrap().ok(),
-            Some(Bytes::from("test"))
-        );
-    }
-
-    #[actix_rt::test]
-    async fn test_string() {
-        let b = "test".to_owned();
-        assert_eq!(Body::from(b.clone()).size(), BodySize::Sized(4));
-        assert_eq!(Body::from(b.clone()).get_ref(), b"test");
-        assert_eq!(Body::from(&b).size(), BodySize::Sized(4));
-        assert_eq!(Body::from(&b).get_ref(), b"test");
-        pin_mut!(b);
-
-        assert_eq!(b.size(), BodySize::Sized(4));
-        assert_eq!(
-            poll_fn(|cx| b.as_mut().poll_next(cx)).await.unwrap().ok(),
-            Some(Bytes::from("test"))
-        );
-    }
-
-    #[actix_rt::test]
-    async fn test_unit() {
-        assert_eq!(().size(), BodySize::Empty);
-        assert!(poll_fn(|cx| Pin::new(&mut ()).poll_next(cx))
-            .await
-            .is_none());
-    }
-
-    #[actix_rt::test]
-    async fn test_box() {
-        let val = Box::new(());
-        pin_mut!(val);
-        assert_eq!(val.size(), BodySize::Empty);
-        assert!(poll_fn(|cx| val.as_mut().poll_next(cx)).await.is_none());
-    }
-
-    #[actix_rt::test]
-    async fn test_body_eq() {
-        assert!(
-            Body::Bytes(Bytes::from_static(b"1"))
-                == Body::Bytes(Bytes::from_static(b"1"))
-        );
-        assert!(Body::Bytes(Bytes::from_static(b"1")) != Body::None);
-    }
-
-    #[actix_rt::test]
-    async fn test_body_debug() {
-        assert!(format!("{:?}", Body::None).contains("Body::None"));
-        assert!(format!("{:?}", Body::Empty).contains("Body::Empty"));
-        assert!(format!("{:?}", Body::Bytes(Bytes::from_static(b"1"))).contains('1'));
-    }
-
-    #[actix_rt::test]
-    async fn test_serde_json() {
-        use serde_json::json;
-        assert_eq!(
-            Body::from(serde_json::Value::String("test".into())).size(),
-            BodySize::Sized(6)
-        );
-        assert_eq!(
-            Body::from(json!({"test-key":"test-value"})).size(),
-            BodySize::Sized(25)
-        );
-    }
-
-    mod body_stream {
-        use super::*;
-        //use futures::task::noop_waker;
-        //use futures::stream::once;
-
-        #[actix_rt::test]
-        async fn skips_empty_chunks() {
-            let body = BodyStream::new(stream::iter(
-                ["1", "", "2"]
-                    .iter()
-                    .map(|&v| Ok(Bytes::from(v)) as Result<Bytes, ()>),
-            ));
-            pin_mut!(body);
-
-            assert_eq!(
-                poll_fn(|cx| body.as_mut().poll_next(cx))
-                    .await
-                    .unwrap()
-                    .ok(),
-                Some(Bytes::from("1")),
-            );
-            assert_eq!(
-                poll_fn(|cx| body.as_mut().poll_next(cx))
-                    .await
-                    .unwrap()
-                    .ok(),
-                Some(Bytes::from("2")),
-            );
-        }
-
-        /* Now it does not compile as it should
-        #[actix_rt::test]
-        async fn move_pinned_pointer() {
-            let (sender, receiver) = futures::channel::oneshot::channel();
-            let mut body_stream = Ok(BodyStream::new(once(async {
-                let x = Box::new(0i32);
-                let y = &x;
-                receiver.await.unwrap();
-                let _z = **y;
-                Ok::<_, ()>(Bytes::new())
-            })));
-
-            let waker = noop_waker();
-            let mut context = Context::from_waker(&waker);
-            pin_mut!(body_stream);
-
-            let _ = body_stream.as_mut().unwrap().poll_next(&mut context);
-            sender.send(()).unwrap();
-            let _ = std::mem::replace(&mut body_stream, Err([0; 32])).unwrap().poll_next(&mut context);
-        }*/
-    }
-
-    mod sized_stream {
-        use super::*;
-
-        #[actix_rt::test]
-        async fn skips_empty_chunks() {
-            let body = SizedStream::new(
-                2,
-                stream::iter(["1", "", "2"].iter().map(|&v| Ok(Bytes::from(v)))),
-            );
-            pin_mut!(body);
-            assert_eq!(
-                poll_fn(|cx| body.as_mut().poll_next(cx))
-                    .await
-                    .unwrap()
-                    .ok(),
-                Some(Bytes::from("1")),
-            );
-            assert_eq!(
-                poll_fn(|cx| body.as_mut().poll_next(cx))
-                    .await
-                    .unwrap()
-                    .ok(),
-                Some(Bytes::from("2")),
-            );
-        }
-    }
-
-    #[actix_rt::test]
-    async fn test_body_casting() {
-        let mut body = String::from("hello cast");
-        let resp_body: &mut dyn MessageBody = &mut body;
-        let body = resp_body.downcast_ref::<String>().unwrap();
-        assert_eq!(body, "hello cast");
-        let body = &mut resp_body.downcast_mut::<String>().unwrap();
-        body.push('!');
-        let body = resp_body.downcast_ref::<String>().unwrap();
-        assert_eq!(body, "hello cast!");
-        let not_body = resp_body.downcast_ref::<()>();
-        assert!(not_body.is_none());
-    }
-}
diff --git a/actix-http/src/body/body.rs b/actix-http/src/body/body.rs
new file mode 100644
index 000000000..a3fd7d41c
--- /dev/null
+++ b/actix-http/src/body/body.rs
@@ -0,0 +1,158 @@
+use std::{
+    fmt, mem,
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use bytes::{Bytes, BytesMut};
+use futures_core::Stream;
+
+use crate::error::Error;
+
+use super::{BodySize, BodyStream, MessageBody, SizedStream};
+
+/// Represents various types of HTTP message body.
+pub enum Body {
+    /// Empty response. `Content-Length` header is not set.
+    None,
+    /// Zero sized response body. `Content-Length` header is set to `0`.
+    Empty,
+    /// Specific response body.
+    Bytes(Bytes),
+    /// Generic message body.
+    Message(Box<dyn MessageBody + Unpin>),
+}
+
+impl Body {
+    /// Create body from slice (copy)
+    pub fn from_slice(s: &[u8]) -> Body {
+        Body::Bytes(Bytes::copy_from_slice(s))
+    }
+
+    /// Create body from generic message body.
+    pub fn from_message<B: MessageBody + Unpin + 'static>(body: B) -> Body {
+        Body::Message(Box::new(body))
+    }
+}
+
+impl MessageBody for Body {
+    fn size(&self) -> BodySize {
+        match self {
+            Body::None => BodySize::None,
+            Body::Empty => BodySize::Empty,
+            Body::Bytes(ref bin) => BodySize::Sized(bin.len() as u64),
+            Body::Message(ref body) => body.size(),
+        }
+    }
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        match self.get_mut() {
+            Body::None => Poll::Ready(None),
+            Body::Empty => Poll::Ready(None),
+            Body::Bytes(ref mut bin) => {
+                let len = bin.len();
+                if len == 0 {
+                    Poll::Ready(None)
+                } else {
+                    Poll::Ready(Some(Ok(mem::take(bin))))
+                }
+            }
+            Body::Message(body) => Pin::new(&mut **body).poll_next(cx),
+        }
+    }
+}
+
+impl PartialEq for Body {
+    fn eq(&self, other: &Body) -> bool {
+        match *self {
+            Body::None => matches!(*other, Body::None),
+            Body::Empty => matches!(*other, Body::Empty),
+            Body::Bytes(ref b) => match *other {
+                Body::Bytes(ref b2) => b == b2,
+                _ => false,
+            },
+            Body::Message(_) => false,
+        }
+    }
+}
+
+impl fmt::Debug for Body {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            Body::None => write!(f, "Body::None"),
+            Body::Empty => write!(f, "Body::Empty"),
+            Body::Bytes(ref b) => write!(f, "Body::Bytes({:?})", b),
+            Body::Message(_) => write!(f, "Body::Message(_)"),
+        }
+    }
+}
+
+impl From<&'static str> for Body {
+    fn from(s: &'static str) -> Body {
+        Body::Bytes(Bytes::from_static(s.as_ref()))
+    }
+}
+
+impl From<&'static [u8]> for Body {
+    fn from(s: &'static [u8]) -> Body {
+        Body::Bytes(Bytes::from_static(s))
+    }
+}
+
+impl From<Vec<u8>> for Body {
+    fn from(vec: Vec<u8>) -> Body {
+        Body::Bytes(Bytes::from(vec))
+    }
+}
+
+impl From<String> for Body {
+    fn from(s: String) -> Body {
+        s.into_bytes().into()
+    }
+}
+
+impl<'a> From<&'a String> for Body {
+    fn from(s: &'a String) -> Body {
+        Body::Bytes(Bytes::copy_from_slice(AsRef::<[u8]>::as_ref(&s)))
+    }
+}
+
+impl From<Bytes> for Body {
+    fn from(s: Bytes) -> Body {
+        Body::Bytes(s)
+    }
+}
+
+impl From<BytesMut> for Body {
+    fn from(s: BytesMut) -> Body {
+        Body::Bytes(s.freeze())
+    }
+}
+
+impl From<serde_json::Value> for Body {
+    fn from(v: serde_json::Value) -> Body {
+        Body::Bytes(v.to_string().into())
+    }
+}
+
+impl<S> From<SizedStream<S>> for Body
+where
+    S: Stream<Item = Result<Bytes, Error>> + Unpin + 'static,
+{
+    fn from(s: SizedStream<S>) -> Body {
+        Body::from_message(s)
+    }
+}
+
+impl<S, E> From<BodyStream<S>> for Body
+where
+    S: Stream<Item = Result<Bytes, E>> + Unpin + 'static,
+    E: Into<Error> + 'static,
+{
+    fn from(s: BodyStream<S>) -> Body {
+        Body::from_message(s)
+    }
+}
diff --git a/actix-http/src/body/body_stream.rs b/actix-http/src/body/body_stream.rs
new file mode 100644
index 000000000..60e33b161
--- /dev/null
+++ b/actix-http/src/body/body_stream.rs
@@ -0,0 +1,59 @@
+use std::{
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use bytes::Bytes;
+use futures_core::{ready, Stream};
+
+use crate::error::Error;
+
+use super::{BodySize, MessageBody};
+
+/// Streaming response wrapper.
+///
+/// Response does not contain `Content-Length` header and appropriate transfer encoding is used.
+pub struct BodyStream<S: Unpin> {
+    stream: S,
+}
+
+impl<S, E> BodyStream<S>
+where
+    S: Stream<Item = Result<Bytes, E>> + Unpin,
+    E: Into<Error>,
+{
+    pub fn new(stream: S) -> Self {
+        BodyStream { stream }
+    }
+}
+
+impl<S, E> MessageBody for BodyStream<S>
+where
+    S: Stream<Item = Result<Bytes, E>> + Unpin,
+    E: Into<Error>,
+{
+    fn size(&self) -> BodySize {
+        BodySize::Stream
+    }
+
+    /// Attempts to pull out the next value of the underlying [`Stream`].
+    ///
+    /// Empty values are skipped to prevent [`BodyStream`]'s transmission being
+    /// ended on a zero-length chunk, but rather proceed until the underlying
+    /// [`Stream`] ends.
+    fn poll_next(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        loop {
+            let stream = &mut self.as_mut().stream;
+
+            let chunk = match ready!(Pin::new(stream).poll_next(cx)) {
+                Some(Ok(ref bytes)) if bytes.is_empty() => continue,
+                opt => opt.map(|res| res.map_err(Into::into)),
+            };
+
+            return Poll::Ready(chunk);
+        }
+    }
+}
diff --git a/actix-http/src/body/message_body.rs b/actix-http/src/body/message_body.rs
new file mode 100644
index 000000000..012329146
--- /dev/null
+++ b/actix-http/src/body/message_body.rs
@@ -0,0 +1,142 @@
+//! [`MessageBody`] trait and foreign implementations.
+
+use std::{
+    mem,
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use bytes::{Bytes, BytesMut};
+
+use crate::error::Error;
+
+use super::BodySize;
+
+/// Type that implement this trait can be streamed to a peer.
+pub trait MessageBody {
+    fn size(&self) -> BodySize;
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>>;
+
+    downcast_get_type_id!();
+}
+
+downcast!(MessageBody);
+
+impl MessageBody for () {
+    fn size(&self) -> BodySize {
+        BodySize::Empty
+    }
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        _: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        Poll::Ready(None)
+    }
+}
+
+impl<T: MessageBody + Unpin> MessageBody for Box<T> {
+    fn size(&self) -> BodySize {
+        self.as_ref().size()
+    }
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        Pin::new(self.get_mut().as_mut()).poll_next(cx)
+    }
+}
+
+impl MessageBody for Bytes {
+    fn size(&self) -> BodySize {
+        BodySize::Sized(self.len() as u64)
+    }
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        _: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        if self.is_empty() {
+            Poll::Ready(None)
+        } else {
+            Poll::Ready(Some(Ok(mem::take(self.get_mut()))))
+        }
+    }
+}
+
+impl MessageBody for BytesMut {
+    fn size(&self) -> BodySize {
+        BodySize::Sized(self.len() as u64)
+    }
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        _: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        if self.is_empty() {
+            Poll::Ready(None)
+        } else {
+            Poll::Ready(Some(Ok(mem::take(self.get_mut()).freeze())))
+        }
+    }
+}
+
+impl MessageBody for &'static str {
+    fn size(&self) -> BodySize {
+        BodySize::Sized(self.len() as u64)
+    }
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        _: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        if self.is_empty() {
+            Poll::Ready(None)
+        } else {
+            Poll::Ready(Some(Ok(Bytes::from_static(
+                mem::take(self.get_mut()).as_ref(),
+            ))))
+        }
+    }
+}
+
+impl MessageBody for Vec<u8> {
+    fn size(&self) -> BodySize {
+        BodySize::Sized(self.len() as u64)
+    }
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        _: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        if self.is_empty() {
+            Poll::Ready(None)
+        } else {
+            Poll::Ready(Some(Ok(Bytes::from(mem::take(self.get_mut())))))
+        }
+    }
+}
+
+impl MessageBody for String {
+    fn size(&self) -> BodySize {
+        BodySize::Sized(self.len() as u64)
+    }
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        _: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        if self.is_empty() {
+            Poll::Ready(None)
+        } else {
+            Poll::Ready(Some(Ok(Bytes::from(
+                mem::take(self.get_mut()).into_bytes(),
+            ))))
+        }
+    }
+}
diff --git a/actix-http/src/body/mod.rs b/actix-http/src/body/mod.rs
new file mode 100644
index 000000000..a4d6ba2b6
--- /dev/null
+++ b/actix-http/src/body/mod.rs
@@ -0,0 +1,252 @@
+//! Traits and structures to aid consuming and writing HTTP payloads.
+
+#[allow(clippy::module_inception)]
+mod body;
+mod body_stream;
+mod message_body;
+mod response_body;
+mod size;
+mod sized_stream;
+
+pub use self::body::Body;
+pub use self::body_stream::BodyStream;
+pub use self::message_body::MessageBody;
+pub use self::response_body::ResponseBody;
+pub use self::size::BodySize;
+pub use self::sized_stream::SizedStream;
+
+#[cfg(test)]
+mod tests {
+    use std::pin::Pin;
+
+    use actix_rt::pin;
+    use bytes::{Bytes, BytesMut};
+    use futures_util::{future::poll_fn, stream};
+
+    use super::*;
+
+    impl Body {
+        pub(crate) fn get_ref(&self) -> &[u8] {
+            match *self {
+                Body::Bytes(ref bin) => &bin,
+                _ => panic!(),
+            }
+        }
+    }
+
+    impl ResponseBody<Body> {
+        pub(crate) fn get_ref(&self) -> &[u8] {
+            match *self {
+                ResponseBody::Body(ref b) => b.get_ref(),
+                ResponseBody::Other(ref b) => b.get_ref(),
+            }
+        }
+    }
+
+    #[actix_rt::test]
+    async fn test_static_str() {
+        assert_eq!(Body::from("").size(), BodySize::Sized(0));
+        assert_eq!(Body::from("test").size(), BodySize::Sized(4));
+        assert_eq!(Body::from("test").get_ref(), b"test");
+
+        assert_eq!("test".size(), BodySize::Sized(4));
+        assert_eq!(
+            poll_fn(|cx| Pin::new(&mut "test").poll_next(cx))
+                .await
+                .unwrap()
+                .ok(),
+            Some(Bytes::from("test"))
+        );
+    }
+
+    #[actix_rt::test]
+    async fn test_static_bytes() {
+        assert_eq!(Body::from(b"test".as_ref()).size(), BodySize::Sized(4));
+        assert_eq!(Body::from(b"test".as_ref()).get_ref(), b"test");
+        assert_eq!(
+            Body::from_slice(b"test".as_ref()).size(),
+            BodySize::Sized(4)
+        );
+        assert_eq!(Body::from_slice(b"test".as_ref()).get_ref(), b"test");
+        let sb = Bytes::from(&b"test"[..]);
+        pin!(sb);
+
+        assert_eq!(sb.size(), BodySize::Sized(4));
+        assert_eq!(
+            poll_fn(|cx| sb.as_mut().poll_next(cx)).await.unwrap().ok(),
+            Some(Bytes::from("test"))
+        );
+    }
+
+    #[actix_rt::test]
+    async fn test_vec() {
+        assert_eq!(Body::from(Vec::from("test")).size(), BodySize::Sized(4));
+        assert_eq!(Body::from(Vec::from("test")).get_ref(), b"test");
+        let test_vec = Vec::from("test");
+        pin!(test_vec);
+
+        assert_eq!(test_vec.size(), BodySize::Sized(4));
+        assert_eq!(
+            poll_fn(|cx| test_vec.as_mut().poll_next(cx))
+                .await
+                .unwrap()
+                .ok(),
+            Some(Bytes::from("test"))
+        );
+    }
+
+    #[actix_rt::test]
+    async fn test_bytes() {
+        let b = Bytes::from("test");
+        assert_eq!(Body::from(b.clone()).size(), BodySize::Sized(4));
+        assert_eq!(Body::from(b.clone()).get_ref(), b"test");
+        pin!(b);
+
+        assert_eq!(b.size(), BodySize::Sized(4));
+        assert_eq!(
+            poll_fn(|cx| b.as_mut().poll_next(cx)).await.unwrap().ok(),
+            Some(Bytes::from("test"))
+        );
+    }
+
+    #[actix_rt::test]
+    async fn test_bytes_mut() {
+        let b = BytesMut::from("test");
+        assert_eq!(Body::from(b.clone()).size(), BodySize::Sized(4));
+        assert_eq!(Body::from(b.clone()).get_ref(), b"test");
+        pin!(b);
+
+        assert_eq!(b.size(), BodySize::Sized(4));
+        assert_eq!(
+            poll_fn(|cx| b.as_mut().poll_next(cx)).await.unwrap().ok(),
+            Some(Bytes::from("test"))
+        );
+    }
+
+    #[actix_rt::test]
+    async fn test_string() {
+        let b = "test".to_owned();
+        assert_eq!(Body::from(b.clone()).size(), BodySize::Sized(4));
+        assert_eq!(Body::from(b.clone()).get_ref(), b"test");
+        assert_eq!(Body::from(&b).size(), BodySize::Sized(4));
+        assert_eq!(Body::from(&b).get_ref(), b"test");
+        pin!(b);
+
+        assert_eq!(b.size(), BodySize::Sized(4));
+        assert_eq!(
+            poll_fn(|cx| b.as_mut().poll_next(cx)).await.unwrap().ok(),
+            Some(Bytes::from("test"))
+        );
+    }
+
+    #[actix_rt::test]
+    async fn test_unit() {
+        assert_eq!(().size(), BodySize::Empty);
+        assert!(poll_fn(|cx| Pin::new(&mut ()).poll_next(cx))
+            .await
+            .is_none());
+    }
+
+    #[actix_rt::test]
+    async fn test_box() {
+        let val = Box::new(());
+        pin!(val);
+        assert_eq!(val.size(), BodySize::Empty);
+        assert!(poll_fn(|cx| val.as_mut().poll_next(cx)).await.is_none());
+    }
+
+    #[actix_rt::test]
+    async fn test_body_eq() {
+        assert!(
+            Body::Bytes(Bytes::from_static(b"1"))
+                == Body::Bytes(Bytes::from_static(b"1"))
+        );
+        assert!(Body::Bytes(Bytes::from_static(b"1")) != Body::None);
+    }
+
+    #[actix_rt::test]
+    async fn test_body_debug() {
+        assert!(format!("{:?}", Body::None).contains("Body::None"));
+        assert!(format!("{:?}", Body::Empty).contains("Body::Empty"));
+        assert!(format!("{:?}", Body::Bytes(Bytes::from_static(b"1"))).contains('1'));
+    }
+
+    #[actix_rt::test]
+    async fn test_serde_json() {
+        use serde_json::json;
+        assert_eq!(
+            Body::from(serde_json::Value::String("test".into())).size(),
+            BodySize::Sized(6)
+        );
+        assert_eq!(
+            Body::from(json!({"test-key":"test-value"})).size(),
+            BodySize::Sized(25)
+        );
+    }
+
+    #[actix_rt::test]
+    async fn body_stream_skips_empty_chunks() {
+        let body = BodyStream::new(stream::iter(
+            ["1", "", "2"]
+                .iter()
+                .map(|&v| Ok(Bytes::from(v)) as Result<Bytes, ()>),
+        ));
+        pin!(body);
+
+        assert_eq!(
+            poll_fn(|cx| body.as_mut().poll_next(cx))
+                .await
+                .unwrap()
+                .ok(),
+            Some(Bytes::from("1")),
+        );
+        assert_eq!(
+            poll_fn(|cx| body.as_mut().poll_next(cx))
+                .await
+                .unwrap()
+                .ok(),
+            Some(Bytes::from("2")),
+        );
+    }
+
+    mod sized_stream {
+        use super::*;
+
+        #[actix_rt::test]
+        async fn skips_empty_chunks() {
+            let body = SizedStream::new(
+                2,
+                stream::iter(["1", "", "2"].iter().map(|&v| Ok(Bytes::from(v)))),
+            );
+            pin!(body);
+            assert_eq!(
+                poll_fn(|cx| body.as_mut().poll_next(cx))
+                    .await
+                    .unwrap()
+                    .ok(),
+                Some(Bytes::from("1")),
+            );
+            assert_eq!(
+                poll_fn(|cx| body.as_mut().poll_next(cx))
+                    .await
+                    .unwrap()
+                    .ok(),
+                Some(Bytes::from("2")),
+            );
+        }
+    }
+
+    #[actix_rt::test]
+    async fn test_body_casting() {
+        let mut body = String::from("hello cast");
+        let resp_body: &mut dyn MessageBody = &mut body;
+        let body = resp_body.downcast_ref::<String>().unwrap();
+        assert_eq!(body, "hello cast");
+        let body = &mut resp_body.downcast_mut::<String>().unwrap();
+        body.push('!');
+        let body = resp_body.downcast_ref::<String>().unwrap();
+        assert_eq!(body, "hello cast!");
+        let not_body = resp_body.downcast_ref::<()>();
+        assert!(not_body.is_none());
+    }
+}
diff --git a/actix-http/src/body/response_body.rs b/actix-http/src/body/response_body.rs
new file mode 100644
index 000000000..97141e11e
--- /dev/null
+++ b/actix-http/src/body/response_body.rs
@@ -0,0 +1,77 @@
+use std::{
+    mem,
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use bytes::Bytes;
+use futures_core::Stream;
+use pin_project::pin_project;
+
+use crate::error::Error;
+
+use super::{Body, BodySize, MessageBody};
+
+#[pin_project(project = ResponseBodyProj)]
+pub enum ResponseBody<B> {
+    Body(#[pin] B),
+    Other(Body),
+}
+
+impl ResponseBody<Body> {
+    pub fn into_body<B>(self) -> ResponseBody<B> {
+        match self {
+            ResponseBody::Body(b) => ResponseBody::Other(b),
+            ResponseBody::Other(b) => ResponseBody::Other(b),
+        }
+    }
+}
+
+impl<B> ResponseBody<B> {
+    pub fn take_body(&mut self) -> ResponseBody<B> {
+        mem::replace(self, ResponseBody::Other(Body::None))
+    }
+}
+
+impl<B: MessageBody> ResponseBody<B> {
+    pub fn as_ref(&self) -> Option<&B> {
+        if let ResponseBody::Body(ref b) = self {
+            Some(b)
+        } else {
+            None
+        }
+    }
+}
+
+impl<B: MessageBody> MessageBody for ResponseBody<B> {
+    fn size(&self) -> BodySize {
+        match self {
+            ResponseBody::Body(ref body) => body.size(),
+            ResponseBody::Other(ref body) => body.size(),
+        }
+    }
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        match self.project() {
+            ResponseBodyProj::Body(body) => body.poll_next(cx),
+            ResponseBodyProj::Other(body) => Pin::new(body).poll_next(cx),
+        }
+    }
+}
+
+impl<B: MessageBody> Stream for ResponseBody<B> {
+    type Item = Result<Bytes, Error>;
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Option<Self::Item>> {
+        match self.project() {
+            ResponseBodyProj::Body(body) => body.poll_next(cx),
+            ResponseBodyProj::Other(body) => Pin::new(body).poll_next(cx),
+        }
+    }
+}
diff --git a/actix-http/src/body/size.rs b/actix-http/src/body/size.rs
new file mode 100644
index 000000000..775d5b8f1
--- /dev/null
+++ b/actix-http/src/body/size.rs
@@ -0,0 +1,40 @@
+/// Body size hint.
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum BodySize {
+    /// Absence of body can be assumed from method or status code.
+    ///
+    /// Will skip writing Content-Length header.
+    None,
+
+    /// Zero size body.
+    ///
+    /// Will write `Content-Length: 0` header.
+    Empty,
+
+    /// Known size body.
+    ///
+    /// Will write `Content-Length: N` header. `Sized(0)` is treated the same as `Empty`.
+    Sized(u64),
+
+    /// Unknown size body.
+    ///
+    /// Will not write Content-Length header. Can be used with chunked Transfer-Encoding.
+    Stream,
+}
+
+impl BodySize {
+    /// Returns true if size hint indicates no or empty body.
+    ///
+    /// ```
+    /// # use actix_http::body::BodySize;
+    /// assert!(BodySize::None.is_eof());
+    /// assert!(BodySize::Empty.is_eof());
+    /// assert!(BodySize::Sized(0).is_eof());
+    ///
+    /// assert!(!BodySize::Sized(64).is_eof());
+    /// assert!(!BodySize::Stream.is_eof());
+    /// ```
+    pub fn is_eof(&self) -> bool {
+        matches!(self, BodySize::None | BodySize::Empty | BodySize::Sized(0))
+    }
+}
diff --git a/actix-http/src/body/sized_stream.rs b/actix-http/src/body/sized_stream.rs
new file mode 100644
index 000000000..af995a0fb
--- /dev/null
+++ b/actix-http/src/body/sized_stream.rs
@@ -0,0 +1,59 @@
+use std::{
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use bytes::Bytes;
+use futures_core::{ready, Stream};
+
+use crate::error::Error;
+
+use super::{BodySize, MessageBody};
+
+/// Known sized streaming response wrapper.
+///
+/// This body implementation should be used if total size of stream is known. Data get sent as is
+/// without using transfer encoding.
+pub struct SizedStream<S: Unpin> {
+    size: u64,
+    stream: S,
+}
+
+impl<S> SizedStream<S>
+where
+    S: Stream<Item = Result<Bytes, Error>> + Unpin,
+{
+    pub fn new(size: u64, stream: S) -> Self {
+        SizedStream { size, stream }
+    }
+}
+
+impl<S> MessageBody for SizedStream<S>
+where
+    S: Stream<Item = Result<Bytes, Error>> + Unpin,
+{
+    fn size(&self) -> BodySize {
+        BodySize::Sized(self.size as u64)
+    }
+
+    /// Attempts to pull out the next value of the underlying [`Stream`].
+    ///
+    /// Empty values are skipped to prevent [`SizedStream`]'s transmission being
+    /// ended on a zero-length chunk, but rather proceed until the underlying
+    /// [`Stream`] ends.
+    fn poll_next(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Option<Result<Bytes, Error>>> {
+        loop {
+            let stream = &mut self.as_mut().stream;
+
+            let chunk = match ready!(Pin::new(stream).poll_next(cx)) {
+                Some(Ok(ref bytes)) if bytes.is_empty() => continue,
+                val => val,
+            };
+
+            return Poll::Ready(chunk);
+        }
+    }
+}
diff --git a/actix-http/src/builder.rs b/actix-http/src/builder.rs
index 271abd43f..fa430c4fe 100644
--- a/actix-http/src/builder.rs
+++ b/actix-http/src/builder.rs
@@ -10,16 +10,16 @@ use crate::config::{KeepAlive, ServiceConfig};
 use crate::error::Error;
 use crate::h1::{Codec, ExpectHandler, H1Service, UpgradeHandler};
 use crate::h2::H2Service;
-use crate::helpers::{Data, DataFactory};
 use crate::request::Request;
 use crate::response::Response;
 use crate::service::HttpService;
+use crate::{ConnectCallback, Extensions};
 
-/// A http service builder
+/// A HTTP service builder
 ///
-/// This type can be used to construct an instance of `http service` through a
+/// This type can be used to construct an instance of [`HttpService`] through a
 /// builder-like pattern.
-pub struct HttpServiceBuilder<T, S, X = ExpectHandler, U = UpgradeHandler<T>> {
+pub struct HttpServiceBuilder<T, S, X = ExpectHandler, U = UpgradeHandler> {
     keep_alive: KeepAlive,
     client_timeout: u64,
     client_disconnect: u64,
@@ -27,16 +27,16 @@ pub struct HttpServiceBuilder<T, S, X = ExpectHandler, U = UpgradeHandler<T>> {
     local_addr: Option<net::SocketAddr>,
     expect: X,
     upgrade: Option<U>,
-    on_connect: Option<Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    _t: PhantomData<(T, S)>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
+    _phantom: PhantomData<S>,
 }
 
-impl<T, S> HttpServiceBuilder<T, S, ExpectHandler, UpgradeHandler<T>>
+impl<T, S> HttpServiceBuilder<T, S, ExpectHandler, UpgradeHandler>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
 {
     /// Create instance of `ServiceConfigBuilder`
     pub fn new() -> Self {
@@ -48,26 +48,26 @@ where
             local_addr: None,
             expect: ExpectHandler,
             upgrade: None,
-            on_connect: None,
-            _t: PhantomData,
+            on_connect_ext: None,
+            _phantom: PhantomData,
         }
     }
 }
 
 impl<T, S, X, U> HttpServiceBuilder<T, S, X, U>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
-    <S::Service as Service>::Future: 'static,
-    X: ServiceFactory<Config = (), Request = Request, Response = Request>,
+    <S::Service as Service<Request>>::Future: 'static,
+    X: ServiceFactory<Request, Config = (), Response = Request>,
     X::Error: Into<Error>,
     X::InitError: fmt::Debug,
-    <X::Service as Service>::Future: 'static,
-    U: ServiceFactory<Config = (), Request = (Request, Framed<T, Codec>), Response = ()>,
+    <X::Service as Service<Request>>::Future: 'static,
+    U: ServiceFactory<(Request, Framed<T, Codec>), Config = (), Response = ()>,
     U::Error: fmt::Display,
     U::InitError: fmt::Debug,
-    <U::Service as Service>::Future: 'static,
+    <U::Service as Service<(Request, Framed<T, Codec>)>>::Future: 'static,
 {
     /// Set server keep-alive setting.
     ///
@@ -123,11 +123,11 @@ where
     /// request will be forwarded to main service.
     pub fn expect<F, X1>(self, expect: F) -> HttpServiceBuilder<T, S, X1, U>
     where
-        F: IntoServiceFactory<X1>,
-        X1: ServiceFactory<Config = (), Request = Request, Response = Request>,
+        F: IntoServiceFactory<X1, Request>,
+        X1: ServiceFactory<Request, Config = (), Response = Request>,
         X1::Error: Into<Error>,
         X1::InitError: fmt::Debug,
-        <X1::Service as Service>::Future: 'static,
+        <X1::Service as Service<Request>>::Future: 'static,
     {
         HttpServiceBuilder {
             keep_alive: self.keep_alive,
@@ -137,8 +137,8 @@ where
             local_addr: self.local_addr,
             expect: expect.into_factory(),
             upgrade: self.upgrade,
-            on_connect: self.on_connect,
-            _t: PhantomData,
+            on_connect_ext: self.on_connect_ext,
+            _phantom: PhantomData,
         }
     }
 
@@ -148,15 +148,11 @@ where
     /// and this service get called with original request and framed object.
     pub fn upgrade<F, U1>(self, upgrade: F) -> HttpServiceBuilder<T, S, X, U1>
     where
-        F: IntoServiceFactory<U1>,
-        U1: ServiceFactory<
-            Config = (),
-            Request = (Request, Framed<T, Codec>),
-            Response = (),
-        >,
+        F: IntoServiceFactory<U1, (Request, Framed<T, Codec>)>,
+        U1: ServiceFactory<(Request, Framed<T, Codec>), Config = (), Response = ()>,
         U1::Error: fmt::Display,
         U1::InitError: fmt::Debug,
-        <U1::Service as Service>::Future: 'static,
+        <U1::Service as Service<(Request, Framed<T, Codec>)>>::Future: 'static,
     {
         HttpServiceBuilder {
             keep_alive: self.keep_alive,
@@ -166,29 +162,29 @@ where
             local_addr: self.local_addr,
             expect: self.expect,
             upgrade: Some(upgrade.into_factory()),
-            on_connect: self.on_connect,
-            _t: PhantomData,
+            on_connect_ext: self.on_connect_ext,
+            _phantom: PhantomData,
         }
     }
 
-    /// Set on-connect callback.
+    /// Sets the callback to be run on connection establishment.
     ///
-    /// It get called once per connection and result of the call
-    /// get stored to the request's extensions.
-    pub fn on_connect<F, I>(mut self, f: F) -> Self
+    /// Has mutable access to a data container that will be merged into request extensions.
+    /// This enables transport layer data (like client certificates) to be accessed in middleware
+    /// and handlers.
+    pub fn on_connect_ext<F>(mut self, f: F) -> Self
     where
-        F: Fn(&T) -> I + 'static,
-        I: Clone + 'static,
+        F: Fn(&T, &mut Extensions) + 'static,
     {
-        self.on_connect = Some(Rc::new(move |io| Box::new(Data(f(io)))));
+        self.on_connect_ext = Some(Rc::new(f));
         self
     }
 
-    /// Finish service configuration and create *http service* for HTTP/1 protocol.
+    /// Finish service configuration and create a HTTP Service for HTTP/1 protocol.
     pub fn h1<F, B>(self, service: F) -> H1Service<T, S, B, X, U>
     where
         B: MessageBody,
-        F: IntoServiceFactory<S>,
+        F: IntoServiceFactory<S, Request>,
         S::Error: Into<Error>,
         S::InitError: fmt::Debug,
         S::Response: Into<Response<B>>,
@@ -200,21 +196,22 @@ where
             self.secure,
             self.local_addr,
         );
+
         H1Service::with_config(cfg, service.into_factory())
             .expect(self.expect)
             .upgrade(self.upgrade)
-            .on_connect(self.on_connect)
+            .on_connect_ext(self.on_connect_ext)
     }
 
-    /// Finish service configuration and create *http service* for HTTP/2 protocol.
+    /// Finish service configuration and create a HTTP service for HTTP/2 protocol.
     pub fn h2<F, B>(self, service: F) -> H2Service<T, S, B>
     where
         B: MessageBody + 'static,
-        F: IntoServiceFactory<S>,
+        F: IntoServiceFactory<S, Request>,
         S::Error: Into<Error> + 'static,
         S::InitError: fmt::Debug,
         S::Response: Into<Response<B>> + 'static,
-        <S::Service as Service>::Future: 'static,
+        <S::Service as Service<Request>>::Future: 'static,
     {
         let cfg = ServiceConfig::new(
             self.keep_alive,
@@ -223,18 +220,20 @@ where
             self.secure,
             self.local_addr,
         );
-        H2Service::with_config(cfg, service.into_factory()).on_connect(self.on_connect)
+
+        H2Service::with_config(cfg, service.into_factory())
+            .on_connect_ext(self.on_connect_ext)
     }
 
     /// Finish service configuration and create `HttpService` instance.
     pub fn finish<F, B>(self, service: F) -> HttpService<T, S, B, X, U>
     where
         B: MessageBody + 'static,
-        F: IntoServiceFactory<S>,
+        F: IntoServiceFactory<S, Request>,
         S::Error: Into<Error> + 'static,
         S::InitError: fmt::Debug,
         S::Response: Into<Response<B>> + 'static,
-        <S::Service as Service>::Future: 'static,
+        <S::Service as Service<Request>>::Future: 'static,
     {
         let cfg = ServiceConfig::new(
             self.keep_alive,
@@ -243,9 +242,10 @@ where
             self.secure,
             self.local_addr,
         );
+
         HttpService::with_config(cfg, service.into_factory())
             .expect(self.expect)
             .upgrade(self.upgrade)
-            .on_connect(self.on_connect)
+            .on_connect_ext(self.on_connect_ext)
     }
 }
diff --git a/actix-http/src/client/config.rs b/actix-http/src/client/config.rs
index c86c697a2..fad902d04 100644
--- a/actix-http/src/client/config.rs
+++ b/actix-http/src/client/config.rs
@@ -1,8 +1,7 @@
 use std::time::Duration;
 
-// These values are taken from hyper/src/proto/h2/client.rs
-const DEFAULT_H2_CONN_WINDOW: u32 = 1024 * 1024 * 2; // 2mb
-const DEFAULT_H2_STREAM_WINDOW: u32 = 1024 * 1024; // 1mb
+const DEFAULT_H2_CONN_WINDOW: u32 = 1024 * 1024 * 2; // 2MB
+const DEFAULT_H2_STREAM_WINDOW: u32 = 1024 * 1024; // 1MB
 
 /// Connector configuration
 #[derive(Clone)]
@@ -19,7 +18,7 @@ pub(crate) struct ConnectorConfig {
 impl Default for ConnectorConfig {
     fn default() -> Self {
         Self {
-            timeout: Duration::from_secs(1),
+            timeout: Duration::from_secs(5),
             conn_lifetime: Duration::from_secs(75),
             conn_keep_alive: Duration::from_secs(15),
             disconnect_timeout: Some(Duration::from_millis(3000)),
diff --git a/actix-http/src/client/connection.rs b/actix-http/src/client/connection.rs
index ec86dabb0..778083a1c 100644
--- a/actix-http/src/client/connection.rs
+++ b/actix-http/src/client/connection.rs
@@ -1,11 +1,12 @@
-use std::future::Future;
+use std::ops::{Deref, DerefMut};
 use std::pin::Pin;
 use std::task::{Context, Poll};
-use std::{fmt, io, mem, time};
+use std::{fmt, io, time};
 
-use actix_codec::{AsyncRead, AsyncWrite, Framed};
-use bytes::{Buf, Bytes};
-use futures_util::future::{err, Either, FutureExt, LocalBoxFuture, Ready};
+use actix_codec::{AsyncRead, AsyncWrite, Framed, ReadBuf};
+use actix_rt::task::JoinHandle;
+use bytes::Bytes;
+use futures_core::future::LocalBoxFuture;
 use h2::client::SendRequest;
 use pin_project::pin_project;
 
@@ -15,33 +16,79 @@ use crate::message::{RequestHeadType, ResponseHead};
 use crate::payload::Payload;
 
 use super::error::SendRequestError;
-use super::pool::{Acquired, Protocol};
+use super::pool::Acquired;
 use super::{h1proto, h2proto};
 
 pub(crate) enum ConnectionType<Io> {
     H1(Io),
-    H2(SendRequest<Bytes>),
+    H2(H2Connection),
+}
+
+/// `H2Connection` has two parts: `SendRequest` and `Connection`.
+///
+/// `Connection` is spawned as an async task on runtime and `H2Connection` holds a handle for
+/// this task. Therefore, it can wake up and quit the task when SendRequest is dropped.
+pub(crate) struct H2Connection {
+    handle: JoinHandle<()>,
+    sender: SendRequest<Bytes>,
+}
+
+impl H2Connection {
+    pub(crate) fn new<Io>(
+        sender: SendRequest<Bytes>,
+        connection: h2::client::Connection<Io>,
+    ) -> Self
+    where
+        Io: AsyncRead + AsyncWrite + Unpin + 'static,
+    {
+        let handle = actix_rt::spawn(async move {
+            let _ = connection.await;
+        });
+
+        Self { handle, sender }
+    }
+}
+
+// cancel spawned connection task on drop.
+impl Drop for H2Connection {
+    fn drop(&mut self) {
+        self.handle.abort();
+    }
+}
+
+// only expose sender type to public.
+impl Deref for H2Connection {
+    type Target = SendRequest<Bytes>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.sender
+    }
+}
+
+impl DerefMut for H2Connection {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.sender
+    }
 }
 
 pub trait Connection {
     type Io: AsyncRead + AsyncWrite + Unpin;
-    type Future: Future<Output = Result<(ResponseHead, Payload), SendRequestError>>;
-
-    fn protocol(&self) -> Protocol;
 
     /// Send request and body
     fn send_request<B: MessageBody + 'static, H: Into<RequestHeadType>>(
         self,
         head: H,
         body: B,
-    ) -> Self::Future;
-
-    type TunnelFuture: Future<
-        Output = Result<(ResponseHead, Framed<Self::Io, ClientCodec>), SendRequestError>,
-    >;
+    ) -> LocalBoxFuture<'static, Result<(ResponseHead, Payload), SendRequestError>>;
 
     /// Send request, returns Response and Framed
-    fn open_tunnel<H: Into<RequestHeadType>>(self, head: H) -> Self::TunnelFuture;
+    fn open_tunnel<H: Into<RequestHeadType> + 'static>(
+        self,
+        head: H,
+    ) -> LocalBoxFuture<
+        'static,
+        Result<(ResponseHead, Framed<Self::Io, ClientCodec>), SendRequestError>,
+    >;
 }
 
 pub(crate) trait ConnectionLifetime: AsyncRead + AsyncWrite + 'static {
@@ -54,7 +101,10 @@ pub(crate) trait ConnectionLifetime: AsyncRead + AsyncWrite + 'static {
 
 #[doc(hidden)]
 /// HTTP client connection
-pub struct IoConnection<T> {
+pub struct IoConnection<T>
+where
+    T: AsyncWrite + Unpin + 'static,
+{
     io: Option<ConnectionType<T>>,
     created: time::Instant,
     pool: Option<Acquired<T>>,
@@ -62,7 +112,7 @@ pub struct IoConnection<T> {
 
 impl<T> fmt::Debug for IoConnection<T>
 where
-    T: fmt::Debug,
+    T: AsyncWrite + Unpin + fmt::Debug + 'static,
 {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.io {
@@ -89,6 +139,11 @@ impl<T: AsyncRead + AsyncWrite + Unpin> IoConnection<T> {
     pub(crate) fn into_inner(self) -> (ConnectionType<T>, time::Instant) {
         (self.io.unwrap(), self.created)
     }
+
+    #[cfg(test)]
+    pub(crate) fn into_parts(self) -> (ConnectionType<T>, time::Instant, Acquired<T>) {
+        (self.io.unwrap(), self.created, self.pool.unwrap())
+    }
 }
 
 impl<T> Connection for IoConnection<T>
@@ -96,48 +151,40 @@ where
     T: AsyncRead + AsyncWrite + Unpin + 'static,
 {
     type Io = T;
-    type Future =
-        LocalBoxFuture<'static, Result<(ResponseHead, Payload), SendRequestError>>;
-
-    fn protocol(&self) -> Protocol {
-        match self.io {
-            Some(ConnectionType::H1(_)) => Protocol::Http1,
-            Some(ConnectionType::H2(_)) => Protocol::Http2,
-            None => Protocol::Http1,
-        }
-    }
 
     fn send_request<B: MessageBody + 'static, H: Into<RequestHeadType>>(
         mut self,
         head: H,
         body: B,
-    ) -> Self::Future {
+    ) -> LocalBoxFuture<'static, Result<(ResponseHead, Payload), SendRequestError>> {
         match self.io.take().unwrap() {
-            ConnectionType::H1(io) => {
-                h1proto::send_request(io, head.into(), body, self.created, self.pool)
-                    .boxed_local()
-            }
-            ConnectionType::H2(io) => {
-                h2proto::send_request(io, head.into(), body, self.created, self.pool)
-                    .boxed_local()
-            }
+            ConnectionType::H1(io) => Box::pin(h1proto::send_request(
+                io,
+                head.into(),
+                body,
+                self.created,
+                self.pool,
+            )),
+            ConnectionType::H2(io) => Box::pin(h2proto::send_request(
+                io,
+                head.into(),
+                body,
+                self.created,
+                self.pool,
+            )),
         }
     }
 
-    type TunnelFuture = Either<
-        LocalBoxFuture<
-            'static,
-            Result<(ResponseHead, Framed<Self::Io, ClientCodec>), SendRequestError>,
-        >,
-        Ready<Result<(ResponseHead, Framed<Self::Io, ClientCodec>), SendRequestError>>,
-    >;
-
     /// Send request, returns Response and Framed
-    fn open_tunnel<H: Into<RequestHeadType>>(mut self, head: H) -> Self::TunnelFuture {
+    fn open_tunnel<H: Into<RequestHeadType>>(
+        mut self,
+        head: H,
+    ) -> LocalBoxFuture<
+        'static,
+        Result<(ResponseHead, Framed<Self::Io, ClientCodec>), SendRequestError>,
+    > {
         match self.io.take().unwrap() {
-            ConnectionType::H1(io) => {
-                Either::Left(h1proto::open_tunnel(io, head.into()).boxed_local())
-            }
+            ConnectionType::H1(io) => Box::pin(h1proto::open_tunnel(io, head.into())),
             ConnectionType::H2(io) => {
                 if let Some(mut pool) = self.pool.take() {
                     pool.release(IoConnection::new(
@@ -146,65 +193,57 @@ where
                         None,
                     ));
                 }
-                Either::Right(err(SendRequestError::TunnelNotSupported))
+                Box::pin(async { Err(SendRequestError::TunnelNotSupported) })
             }
         }
     }
 }
 
 #[allow(dead_code)]
-pub(crate) enum EitherConnection<A, B> {
+pub(crate) enum EitherIoConnection<A, B>
+where
+    A: AsyncRead + AsyncWrite + Unpin + 'static,
+    B: AsyncRead + AsyncWrite + Unpin + 'static,
+{
     A(IoConnection<A>),
     B(IoConnection<B>),
 }
 
-impl<A, B> Connection for EitherConnection<A, B>
+impl<A, B> Connection for EitherIoConnection<A, B>
 where
     A: AsyncRead + AsyncWrite + Unpin + 'static,
     B: AsyncRead + AsyncWrite + Unpin + 'static,
 {
     type Io = EitherIo<A, B>;
-    type Future =
-        LocalBoxFuture<'static, Result<(ResponseHead, Payload), SendRequestError>>;
-
-    fn protocol(&self) -> Protocol {
-        match self {
-            EitherConnection::A(con) => con.protocol(),
-            EitherConnection::B(con) => con.protocol(),
-        }
-    }
 
     fn send_request<RB: MessageBody + 'static, H: Into<RequestHeadType>>(
         self,
         head: H,
         body: RB,
-    ) -> Self::Future {
+    ) -> LocalBoxFuture<'static, Result<(ResponseHead, Payload), SendRequestError>> {
         match self {
-            EitherConnection::A(con) => con.send_request(head, body),
-            EitherConnection::B(con) => con.send_request(head, body),
+            EitherIoConnection::A(con) => con.send_request(head, body),
+            EitherIoConnection::B(con) => con.send_request(head, body),
         }
     }
 
-    type TunnelFuture = LocalBoxFuture<
+    /// Send request, returns Response and Framed
+    fn open_tunnel<H: Into<RequestHeadType> + 'static>(
+        self,
+        head: H,
+    ) -> LocalBoxFuture<
         'static,
         Result<(ResponseHead, Framed<Self::Io, ClientCodec>), SendRequestError>,
-    >;
-
-    /// Send request, returns Response and Framed
-    fn open_tunnel<H: Into<RequestHeadType>>(self, head: H) -> Self::TunnelFuture {
+    > {
         match self {
-            EitherConnection::A(con) => con
-                .open_tunnel(head)
-                .map(|res| {
-                    res.map(|(head, framed)| (head, framed.into_map_io(EitherIo::A)))
-                })
-                .boxed_local(),
-            EitherConnection::B(con) => con
-                .open_tunnel(head)
-                .map(|res| {
-                    res.map(|(head, framed)| (head, framed.into_map_io(EitherIo::B)))
-                })
-                .boxed_local(),
+            EitherIoConnection::A(con) => Box::pin(async {
+                let (head, framed) = con.open_tunnel(head).await?;
+                Ok((head, framed.into_map_io(EitherIo::A)))
+            }),
+            EitherIoConnection::B(con) => Box::pin(async {
+                let (head, framed) = con.open_tunnel(head).await?;
+                Ok((head, framed.into_map_io(EitherIo::B)))
+            }),
         }
     }
 }
@@ -223,23 +262,13 @@ where
     fn poll_read(
         self: Pin<&mut Self>,
         cx: &mut Context<'_>,
-        buf: &mut [u8],
-    ) -> Poll<io::Result<usize>> {
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
         match self.project() {
             EitherIoProj::A(val) => val.poll_read(cx, buf),
             EitherIoProj::B(val) => val.poll_read(cx, buf),
         }
     }
-
-    unsafe fn prepare_uninitialized_buffer(
-        &self,
-        buf: &mut [mem::MaybeUninit<u8>],
-    ) -> bool {
-        match self {
-            EitherIo::A(ref val) => val.prepare_uninitialized_buffer(buf),
-            EitherIo::B(ref val) => val.prepare_uninitialized_buffer(buf),
-        }
-    }
 }
 
 impl<A, B> AsyncWrite for EitherIo<A, B>
@@ -274,18 +303,36 @@ where
             EitherIoProj::B(val) => val.poll_shutdown(cx),
         }
     }
+}
 
-    fn poll_write_buf<U: Buf>(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-        buf: &mut U,
-    ) -> Poll<Result<usize, io::Error>>
-    where
-        Self: Sized,
-    {
-        match self.project() {
-            EitherIoProj::A(val) => val.poll_write_buf(cx, buf),
-            EitherIoProj::B(val) => val.poll_write_buf(cx, buf),
-        }
+#[cfg(test)]
+mod test {
+    use std::net;
+
+    use actix_rt::net::TcpStream;
+
+    use super::*;
+
+    #[actix_rt::test]
+    async fn test_h2_connection_drop() {
+        let addr = "127.0.0.1:0".parse::<net::SocketAddr>().unwrap();
+        let listener = net::TcpListener::bind(addr).unwrap();
+        let local = listener.local_addr().unwrap();
+
+        std::thread::spawn(move || while listener.accept().is_ok() {});
+
+        let tcp = TcpStream::connect(local).await.unwrap();
+        let (sender, connection) = h2::client::handshake(tcp).await.unwrap();
+        let conn = H2Connection::new(sender.clone(), connection);
+
+        assert!(sender.clone().ready().await.is_ok());
+        assert!(h2::client::SendRequest::clone(&*conn).ready().await.is_ok());
+
+        drop(conn);
+
+        match sender.ready().await {
+            Ok(_) => panic!("connection should be gone and can not be ready"),
+            Err(e) => assert!(e.is_io()),
+        };
     }
 }
diff --git a/actix-http/src/client/connector.rs b/actix-http/src/client/connector.rs
index e1aed6382..65536f257 100644
--- a/actix-http/src/client/connector.rs
+++ b/actix-http/src/client/connector.rs
@@ -3,11 +3,11 @@ use std::marker::PhantomData;
 use std::time::Duration;
 
 use actix_codec::{AsyncRead, AsyncWrite};
-use actix_connect::{
-    default_connector, Connect as TcpConnect, Connection as TcpConnection,
-};
 use actix_rt::net::TcpStream;
-use actix_service::{apply_fn, Service};
+use actix_service::{apply_fn, Service, ServiceExt};
+use actix_tls::connect::{
+    new_connector, Connect as TcpConnect, Connection as TcpConnection, Resolver,
+};
 use actix_utils::timeout::{TimeoutError, TimeoutService};
 use http::Uri;
 
@@ -18,10 +18,9 @@ use super::pool::{ConnectionPool, Protocol};
 use super::Connect;
 
 #[cfg(feature = "openssl")]
-use actix_connect::ssl::openssl::SslConnector as OpensslConnector;
-
+use actix_tls::connect::ssl::openssl::SslConnector as OpensslConnector;
 #[cfg(feature = "rustls")]
-use actix_connect::ssl::rustls::ClientConfig;
+use actix_tls::connect::ssl::rustls::ClientConfig;
 #[cfg(feature = "rustls")]
 use std::sync::Arc;
 
@@ -35,7 +34,8 @@ enum SslConnector {
 #[cfg(not(any(feature = "openssl", feature = "rustls")))]
 type SslConnector = ();
 
-/// Manages http client network connectivity
+/// Manages HTTP client network connectivity.
+///
 /// The `Connector` type uses a builder-like combinator pattern for service
 /// construction that finishes by calling the `.finish()` method.
 ///
@@ -52,7 +52,7 @@ pub struct Connector<T, U> {
     config: ConnectorConfig,
     #[allow(dead_code)]
     ssl: SslConnector,
-    _t: PhantomData<U>,
+    _phantom: PhantomData<U>,
 }
 
 trait Io: AsyncRead + AsyncWrite + Unpin {}
@@ -62,24 +62,24 @@ impl Connector<(), ()> {
     #[allow(clippy::new_ret_no_self, clippy::let_unit_value)]
     pub fn new() -> Connector<
         impl Service<
-                Request = TcpConnect<Uri>,
+                TcpConnect<Uri>,
                 Response = TcpConnection<Uri, TcpStream>,
-                Error = actix_connect::ConnectError,
+                Error = actix_tls::connect::ConnectError,
             > + Clone,
         TcpStream,
     > {
         Connector {
             ssl: Self::build_ssl(vec![b"h2".to_vec(), b"http/1.1".to_vec()]),
-            connector: default_connector(),
+            connector: new_connector(resolver::resolver()),
             config: ConnectorConfig::default(),
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 
     // Build Ssl connector with openssl, based on supplied alpn protocols
     #[cfg(feature = "openssl")]
     fn build_ssl(protocols: Vec<Vec<u8>>) -> SslConnector {
-        use actix_connect::ssl::openssl::SslMethod;
+        use actix_tls::connect::ssl::openssl::SslMethod;
         use bytes::{BufMut, BytesMut};
 
         let mut alpn = BytesMut::with_capacity(20);
@@ -100,9 +100,9 @@ impl Connector<(), ()> {
     fn build_ssl(protocols: Vec<Vec<u8>>) -> SslConnector {
         let mut config = ClientConfig::new();
         config.set_protocols(&protocols);
-        config
-            .root_store
-            .add_server_trust_anchors(&actix_tls::rustls::TLS_SERVER_ROOTS);
+        config.root_store.add_server_trust_anchors(
+            &actix_tls::connect::ssl::rustls::TLS_SERVER_ROOTS,
+        );
         SslConnector::Rustls(Arc::new(config))
     }
 
@@ -117,16 +117,16 @@ impl<T, U> Connector<T, U> {
     where
         U1: AsyncRead + AsyncWrite + Unpin + fmt::Debug,
         T1: Service<
-                Request = TcpConnect<Uri>,
+                TcpConnect<Uri>,
                 Response = TcpConnection<Uri, U1>,
-                Error = actix_connect::ConnectError,
+                Error = actix_tls::connect::ConnectError,
             > + Clone,
     {
         Connector {
             connector,
             config: self.config,
             ssl: self.ssl,
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
@@ -135,9 +135,9 @@ impl<T, U> Connector<T, U>
 where
     U: AsyncRead + AsyncWrite + Unpin + fmt::Debug + 'static,
     T: Service<
-            Request = TcpConnect<Uri>,
+            TcpConnect<Uri>,
             Response = TcpConnection<Uri, U>,
-            Error = actix_connect::ConnectError,
+            Error = actix_tls::connect::ConnectError,
         > + Clone
         + 'static,
 {
@@ -161,8 +161,9 @@ where
         self
     }
 
-    /// Maximum supported http major version
-    /// Supported versions http/1.1, http/2
+    /// Maximum supported HTTP major version.
+    ///
+    /// Supported versions are HTTP/1.1 and HTTP/2.
     pub fn max_http_version(mut self, val: http::Version) -> Self {
         let versions = match val {
             http::Version::HTTP_11 => vec![b"http/1.1".to_vec()],
@@ -241,8 +242,8 @@ where
     /// its combinator chain.
     pub fn finish(
         self,
-    ) -> impl Service<Request = Connect, Response = impl Connection, Error = ConnectError>
-           + Clone {
+    ) -> impl Service<Connect, Response = impl Connection, Error = ConnectError> + Clone
+    {
         #[cfg(not(any(feature = "openssl", feature = "rustls")))]
         {
             let connector = TimeoutService::new(
@@ -268,11 +269,11 @@ where
         #[cfg(any(feature = "openssl", feature = "rustls"))]
         {
             const H2: &[u8] = b"h2";
-            #[cfg(feature = "openssl")]
-            use actix_connect::ssl::openssl::OpensslConnector;
-            #[cfg(feature = "rustls")]
-            use actix_connect::ssl::rustls::{RustlsConnector, Session};
             use actix_service::{boxed::service, pipeline};
+            #[cfg(feature = "openssl")]
+            use actix_tls::connect::ssl::openssl::OpensslConnector;
+            #[cfg(feature = "rustls")]
+            use actix_tls::connect::ssl::rustls::{RustlsConnector, Session};
 
             let ssl_service = TimeoutService::new(
                 self.config.timeout,
@@ -355,7 +356,7 @@ where
 mod connect_impl {
     use std::task::{Context, Poll};
 
-    use futures_util::future::{err, Either, Ready};
+    use futures_core::future::LocalBoxFuture;
 
     use super::*;
     use crate::client::connection::IoConnection;
@@ -363,8 +364,7 @@ mod connect_impl {
     pub(crate) struct InnerConnector<T, Io>
     where
         Io: AsyncRead + AsyncWrite + Unpin + 'static,
-        T: Service<Request = Connect, Response = (Io, Protocol), Error = ConnectError>
-            + 'static,
+        T: Service<Connect, Response = (Io, Protocol), Error = ConnectError> + 'static,
     {
         pub(crate) tcp_pool: ConnectionPool<T, Io>,
     }
@@ -372,8 +372,7 @@ mod connect_impl {
     impl<T, Io> Clone for InnerConnector<T, Io>
     where
         Io: AsyncRead + AsyncWrite + Unpin + 'static,
-        T: Service<Request = Connect, Response = (Io, Protocol), Error = ConnectError>
-            + 'static,
+        T: Service<Connect, Response = (Io, Protocol), Error = ConnectError> + 'static,
     {
         fn clone(&self) -> Self {
             InnerConnector {
@@ -382,30 +381,25 @@ mod connect_impl {
         }
     }
 
-    impl<T, Io> Service for InnerConnector<T, Io>
+    impl<T, Io> Service<Connect> for InnerConnector<T, Io>
     where
         Io: AsyncRead + AsyncWrite + Unpin + 'static,
-        T: Service<Request = Connect, Response = (Io, Protocol), Error = ConnectError>
-            + 'static,
+        T: Service<Connect, Response = (Io, Protocol), Error = ConnectError> + 'static,
     {
-        type Request = Connect;
         type Response = IoConnection<Io>;
         type Error = ConnectError;
-        type Future = Either<
-            <ConnectionPool<T, Io> as Service>::Future,
-            Ready<Result<IoConnection<Io>, ConnectError>>,
-        >;
+        type Future = LocalBoxFuture<'static, Result<IoConnection<Io>, ConnectError>>;
 
-        fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
             self.tcp_pool.poll_ready(cx)
         }
 
-        fn call(&mut self, req: Connect) -> Self::Future {
+        fn call(&self, req: Connect) -> Self::Future {
             match req.uri.scheme_str() {
                 Some("https") | Some("wss") => {
-                    Either::Right(err(ConnectError::SslIsNotSupported))
+                    Box::pin(async { Err(ConnectError::SslIsNotSupported) })
                 }
-                _ => Either::Left(self.tcp_pool.call(req)),
+                _ => self.tcp_pool.call(req),
             }
         }
     }
@@ -414,35 +408,29 @@ mod connect_impl {
 #[cfg(any(feature = "openssl", feature = "rustls"))]
 mod connect_impl {
     use std::future::Future;
-    use std::marker::PhantomData;
     use std::pin::Pin;
     use std::task::{Context, Poll};
 
-    use futures_core::ready;
-    use futures_util::future::Either;
-
     use super::*;
-    use crate::client::connection::EitherConnection;
+    use crate::client::connection::EitherIoConnection;
 
-    pub(crate) struct InnerConnector<T1, T2, Io1, Io2>
+    pub(crate) struct InnerConnector<S1, S2, Io1, Io2>
     where
+        S1: Service<Connect, Response = (Io1, Protocol), Error = ConnectError> + 'static,
+        S2: Service<Connect, Response = (Io2, Protocol), Error = ConnectError> + 'static,
         Io1: AsyncRead + AsyncWrite + Unpin + 'static,
         Io2: AsyncRead + AsyncWrite + Unpin + 'static,
-        T1: Service<Request = Connect, Response = (Io1, Protocol), Error = ConnectError>,
-        T2: Service<Request = Connect, Response = (Io2, Protocol), Error = ConnectError>,
     {
-        pub(crate) tcp_pool: ConnectionPool<T1, Io1>,
-        pub(crate) ssl_pool: ConnectionPool<T2, Io2>,
+        pub(crate) tcp_pool: ConnectionPool<S1, Io1>,
+        pub(crate) ssl_pool: ConnectionPool<S2, Io2>,
     }
 
-    impl<T1, T2, Io1, Io2> Clone for InnerConnector<T1, T2, Io1, Io2>
+    impl<S1, S2, Io1, Io2> Clone for InnerConnector<S1, S2, Io1, Io2>
     where
+        S1: Service<Connect, Response = (Io1, Protocol), Error = ConnectError> + 'static,
+        S2: Service<Connect, Response = (Io2, Protocol), Error = ConnectError> + 'static,
         Io1: AsyncRead + AsyncWrite + Unpin + 'static,
         Io2: AsyncRead + AsyncWrite + Unpin + 'static,
-        T1: Service<Request = Connect, Response = (Io1, Protocol), Error = ConnectError>
-            + 'static,
-        T2: Service<Request = Connect, Response = (Io2, Protocol), Error = ConnectError>
-            + 'static,
     {
         fn clone(&self) -> Self {
             InnerConnector {
@@ -452,96 +440,140 @@ mod connect_impl {
         }
     }
 
-    impl<T1, T2, Io1, Io2> Service for InnerConnector<T1, T2, Io1, Io2>
+    impl<S1, S2, Io1, Io2> Service<Connect> for InnerConnector<S1, S2, Io1, Io2>
     where
+        S1: Service<Connect, Response = (Io1, Protocol), Error = ConnectError> + 'static,
+        S2: Service<Connect, Response = (Io2, Protocol), Error = ConnectError> + 'static,
         Io1: AsyncRead + AsyncWrite + Unpin + 'static,
         Io2: AsyncRead + AsyncWrite + Unpin + 'static,
-        T1: Service<Request = Connect, Response = (Io1, Protocol), Error = ConnectError>
-            + 'static,
-        T2: Service<Request = Connect, Response = (Io2, Protocol), Error = ConnectError>
-            + 'static,
     {
-        type Request = Connect;
-        type Response = EitherConnection<Io1, Io2>;
+        type Response = EitherIoConnection<Io1, Io2>;
         type Error = ConnectError;
-        type Future = Either<
-            InnerConnectorResponseA<T1, Io1, Io2>,
-            InnerConnectorResponseB<T2, Io1, Io2>,
-        >;
+        type Future = InnerConnectorResponse<S1, S2, Io1, Io2>;
 
-        fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
             self.tcp_pool.poll_ready(cx)
         }
 
-        fn call(&mut self, req: Connect) -> Self::Future {
+        fn call(&self, req: Connect) -> Self::Future {
             match req.uri.scheme_str() {
-                Some("https") | Some("wss") => Either::Right(InnerConnectorResponseB {
-                    fut: self.ssl_pool.call(req),
-                    _t: PhantomData,
-                }),
-                _ => Either::Left(InnerConnectorResponseA {
-                    fut: self.tcp_pool.call(req),
-                    _t: PhantomData,
-                }),
+                Some("https") | Some("wss") => {
+                    InnerConnectorResponse::Io2(self.ssl_pool.call(req))
+                }
+                _ => InnerConnectorResponse::Io1(self.tcp_pool.call(req)),
             }
         }
     }
 
-    #[pin_project::pin_project]
-    pub(crate) struct InnerConnectorResponseA<T, Io1, Io2>
+    #[pin_project::pin_project(project = InnerConnectorProj)]
+    pub(crate) enum InnerConnectorResponse<S1, S2, Io1, Io2>
     where
-        Io1: AsyncRead + AsyncWrite + Unpin + 'static,
-        T: Service<Request = Connect, Response = (Io1, Protocol), Error = ConnectError>
-            + 'static,
-    {
-        #[pin]
-        fut: <ConnectionPool<T, Io1> as Service>::Future,
-        _t: PhantomData<Io2>,
-    }
-
-    impl<T, Io1, Io2> Future for InnerConnectorResponseA<T, Io1, Io2>
-    where
-        T: Service<Request = Connect, Response = (Io1, Protocol), Error = ConnectError>
-            + 'static,
+        S1: Service<Connect, Response = (Io1, Protocol), Error = ConnectError> + 'static,
+        S2: Service<Connect, Response = (Io2, Protocol), Error = ConnectError> + 'static,
         Io1: AsyncRead + AsyncWrite + Unpin + 'static,
         Io2: AsyncRead + AsyncWrite + Unpin + 'static,
     {
-        type Output = Result<EitherConnection<Io1, Io2>, ConnectError>;
+        Io1(#[pin] <ConnectionPool<S1, Io1> as Service<Connect>>::Future),
+        Io2(#[pin] <ConnectionPool<S2, Io2> as Service<Connect>>::Future),
+    }
+
+    impl<S1, S2, Io1, Io2> Future for InnerConnectorResponse<S1, S2, Io1, Io2>
+    where
+        S1: Service<Connect, Response = (Io1, Protocol), Error = ConnectError> + 'static,
+        S2: Service<Connect, Response = (Io2, Protocol), Error = ConnectError> + 'static,
+        Io1: AsyncRead + AsyncWrite + Unpin + 'static,
+        Io2: AsyncRead + AsyncWrite + Unpin + 'static,
+    {
+        type Output = Result<EitherIoConnection<Io1, Io2>, ConnectError>;
 
         fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-            Poll::Ready(
-                ready!(Pin::new(&mut self.get_mut().fut).poll(cx))
-                    .map(EitherConnection::A),
-            )
-        }
-    }
-
-    #[pin_project::pin_project]
-    pub(crate) struct InnerConnectorResponseB<T, Io1, Io2>
-    where
-        Io2: AsyncRead + AsyncWrite + Unpin + 'static,
-        T: Service<Request = Connect, Response = (Io2, Protocol), Error = ConnectError>
-            + 'static,
-    {
-        #[pin]
-        fut: <ConnectionPool<T, Io2> as Service>::Future,
-        _t: PhantomData<Io1>,
-    }
-
-    impl<T, Io1, Io2> Future for InnerConnectorResponseB<T, Io1, Io2>
-    where
-        T: Service<Request = Connect, Response = (Io2, Protocol), Error = ConnectError>
-            + 'static,
-        Io1: AsyncRead + AsyncWrite + Unpin + 'static,
-        Io2: AsyncRead + AsyncWrite + Unpin + 'static,
-    {
-        type Output = Result<EitherConnection<Io1, Io2>, ConnectError>;
-
-        fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-            Poll::Ready(
-                ready!(Pin::new(&mut self.get_mut().fut).poll(cx))
-                    .map(EitherConnection::B),
-            )
+            match self.project() {
+                InnerConnectorProj::Io1(fut) => {
+                    fut.poll(cx).map_ok(EitherIoConnection::A)
+                }
+                InnerConnectorProj::Io2(fut) => {
+                    fut.poll(cx).map_ok(EitherIoConnection::B)
+                }
+            }
         }
     }
 }
+
+#[cfg(not(feature = "trust-dns"))]
+mod resolver {
+    use super::*;
+
+    pub(super) fn resolver() -> Resolver {
+        Resolver::Default
+    }
+}
+
+#[cfg(feature = "trust-dns")]
+mod resolver {
+    use std::{cell::RefCell, net::SocketAddr};
+
+    use actix_tls::connect::Resolve;
+    use futures_core::future::LocalBoxFuture;
+    use trust_dns_resolver::{
+        config::{ResolverConfig, ResolverOpts},
+        system_conf::read_system_conf,
+        TokioAsyncResolver,
+    };
+
+    use super::*;
+
+    pub(super) fn resolver() -> Resolver {
+        // new type for impl Resolve trait for TokioAsyncResolver.
+        struct TrustDnsResolver(TokioAsyncResolver);
+
+        impl Resolve for TrustDnsResolver {
+            fn lookup<'a>(
+                &'a self,
+                host: &'a str,
+                port: u16,
+            ) -> LocalBoxFuture<'a, Result<Vec<SocketAddr>, Box<dyn std::error::Error>>>
+            {
+                Box::pin(async move {
+                    let res = self
+                        .0
+                        .lookup_ip(host)
+                        .await?
+                        .iter()
+                        .map(|ip| SocketAddr::new(ip, port))
+                        .collect();
+                    Ok(res)
+                })
+            }
+        }
+
+        // dns struct is cached in thread local.
+        // so new client constructor can reuse the existing dns resolver.
+        thread_local! {
+            static TRUST_DNS_RESOLVER: RefCell<Option<Resolver>> = RefCell::new(None);
+        }
+
+        // get from thread local or construct a new trust-dns resolver.
+        TRUST_DNS_RESOLVER.with(|local| {
+            let resolver = local.borrow().as_ref().map(Clone::clone);
+            match resolver {
+                Some(resolver) => resolver,
+                None => {
+                    let (cfg, opts) = match read_system_conf() {
+                        Ok((cfg, opts)) => (cfg, opts),
+                        Err(e) => {
+                            log::error!("TRust-DNS can not load system config: {}", e);
+                            (ResolverConfig::default(), ResolverOpts::default())
+                        }
+                    };
+
+                    let resolver = TokioAsyncResolver::tokio(cfg, opts).unwrap();
+
+                    // box trust dns resolver and put it in thread local.
+                    let resolver = Resolver::new_custom(TrustDnsResolver(resolver));
+                    *local.borrow_mut() = Some(resolver.clone());
+                    resolver
+                }
+            }
+        })
+    }
+}
diff --git a/actix-http/src/client/error.rs b/actix-http/src/client/error.rs
index ba697bca4..d27363456 100644
--- a/actix-http/src/client/error.rs
+++ b/actix-http/src/client/error.rs
@@ -1,10 +1,9 @@
 use std::io;
 
-use actix_connect::resolver::ResolveError;
 use derive_more::{Display, From};
 
 #[cfg(feature = "openssl")]
-use actix_connect::ssl::openssl::{HandshakeError, SslError};
+use actix_tls::accept::openssl::SslError;
 
 use crate::error::{Error, ParseError, ResponseError};
 use crate::http::{Error as HttpError, StatusCode};
@@ -21,17 +20,12 @@ pub enum ConnectError {
     #[display(fmt = "{}", _0)]
     SslError(SslError),
 
-    /// SSL Handshake error
-    #[cfg(feature = "openssl")]
-    #[display(fmt = "{}", _0)]
-    SslHandshakeError(String),
-
     /// Failed to resolve the hostname
     #[display(fmt = "Failed resolving hostname: {}", _0)]
-    Resolver(ResolveError),
+    Resolver(Box<dyn std::error::Error>),
 
     /// No dns records
-    #[display(fmt = "No dns records found for the input")]
+    #[display(fmt = "No DNS records found for the input")]
     NoRecords,
 
     /// Http2 error
@@ -57,34 +51,30 @@ pub enum ConnectError {
 
 impl std::error::Error for ConnectError {}
 
-impl From<actix_connect::ConnectError> for ConnectError {
-    fn from(err: actix_connect::ConnectError) -> ConnectError {
+impl From<actix_tls::connect::ConnectError> for ConnectError {
+    fn from(err: actix_tls::connect::ConnectError) -> ConnectError {
         match err {
-            actix_connect::ConnectError::Resolver(e) => ConnectError::Resolver(e),
-            actix_connect::ConnectError::NoRecords => ConnectError::NoRecords,
-            actix_connect::ConnectError::InvalidInput => panic!(),
-            actix_connect::ConnectError::Unresolved => ConnectError::Unresolved,
-            actix_connect::ConnectError::Io(e) => ConnectError::Io(e),
+            actix_tls::connect::ConnectError::Resolver(e) => ConnectError::Resolver(e),
+            actix_tls::connect::ConnectError::NoRecords => ConnectError::NoRecords,
+            actix_tls::connect::ConnectError::InvalidInput => panic!(),
+            actix_tls::connect::ConnectError::Unresolved => ConnectError::Unresolved,
+            actix_tls::connect::ConnectError::Io(e) => ConnectError::Io(e),
         }
     }
 }
 
-#[cfg(feature = "openssl")]
-impl<T: std::fmt::Debug> From<HandshakeError<T>> for ConnectError {
-    fn from(err: HandshakeError<T>) -> ConnectError {
-        ConnectError::SslHandshakeError(format!("{:?}", err))
-    }
-}
-
 #[derive(Debug, Display, From)]
 pub enum InvalidUrl {
-    #[display(fmt = "Missing url scheme")]
+    #[display(fmt = "Missing URL scheme")]
     MissingScheme,
-    #[display(fmt = "Unknown url scheme")]
+
+    #[display(fmt = "Unknown URL scheme")]
     UnknownScheme,
+
     #[display(fmt = "Missing host name")]
     MissingHost,
-    #[display(fmt = "Url parse error: {}", _0)]
+
+    #[display(fmt = "URL parse error: {}", _0)]
     HttpError(http::Error),
 }
 
@@ -96,25 +86,33 @@ pub enum SendRequestError {
     /// Invalid URL
     #[display(fmt = "Invalid URL: {}", _0)]
     Url(InvalidUrl),
+
     /// Failed to connect to host
     #[display(fmt = "Failed to connect to host: {}", _0)]
     Connect(ConnectError),
+
     /// Error sending request
     Send(io::Error),
+
     /// Error parsing response
     Response(ParseError),
+
     /// Http error
     #[display(fmt = "{}", _0)]
     Http(HttpError),
+
     /// Http2 error
     #[display(fmt = "{}", _0)]
     H2(h2::Error),
+
     /// Response took too long
     #[display(fmt = "Timeout while waiting for response")]
     Timeout,
-    /// Tunnels are not supported for http2 connection
+
+    /// Tunnels are not supported for HTTP/2 connection
     #[display(fmt = "Tunnels are not supported for http2 connection")]
     TunnelNotSupported,
+
     /// Error sending request body
     Body(Error),
 }
@@ -140,7 +138,8 @@ pub enum FreezeRequestError {
     /// Invalid URL
     #[display(fmt = "Invalid URL: {}", _0)]
     Url(InvalidUrl),
-    /// Http error
+
+    /// HTTP error
     #[display(fmt = "{}", _0)]
     Http(HttpError),
 }
diff --git a/actix-http/src/client/h1proto.rs b/actix-http/src/client/h1proto.rs
index 06cc05404..082c4b8e2 100644
--- a/actix-http/src/client/h1proto.rs
+++ b/actix-http/src/client/h1proto.rs
@@ -1,14 +1,14 @@
 use std::io::Write;
 use std::pin::Pin;
 use std::task::{Context, Poll};
-use std::{io, mem, time};
+use std::{io, time};
 
-use actix_codec::{AsyncRead, AsyncWrite, Framed};
-use bytes::buf::BufMutExt;
+use actix_codec::{AsyncRead, AsyncWrite, Framed, ReadBuf};
+use bytes::buf::BufMut;
 use bytes::{Bytes, BytesMut};
 use futures_core::Stream;
 use futures_util::future::poll_fn;
-use futures_util::{pin_mut, SinkExt, StreamExt};
+use futures_util::{SinkExt, StreamExt};
 
 use crate::error::PayloadError;
 use crate::h1;
@@ -45,14 +45,14 @@ where
                 Some(port) => write!(wrt, "{}:{}", host, port),
             };
 
-            match wrt.get_mut().split().freeze().try_into() {
+            match wrt.get_mut().split().freeze().try_into_value() {
                 Ok(value) => match head {
                     RequestHeadType::Owned(ref mut head) => {
-                        head.headers.insert(HOST, value)
+                        head.headers.insert(HOST, value);
                     }
                     RequestHeadType::Rc(_, ref mut extra_headers) => {
                         let headers = extra_headers.get_or_insert(HeaderMap::new());
-                        headers.insert(HOST, value)
+                        headers.insert(HOST, value);
                     }
                 },
                 Err(e) => log::error!("Can not set HOST header {}", e),
@@ -72,7 +72,7 @@ where
 
     // send request body
     match body.size() {
-        BodySize::None | BodySize::Empty | BodySize::Sized(0) => (),
+        BodySize::None | BodySize::Empty | BodySize::Sized(0) => {}
         _ => send_body(body, Pin::new(&mut framed_inner)).await?,
     };
 
@@ -127,7 +127,7 @@ where
     T: ConnectionLifetime + Unpin,
     B: MessageBody,
 {
-    pin_mut!(body);
+    actix_rt::pin!(body);
 
     let mut eof = false;
     while !eof {
@@ -165,7 +165,10 @@ where
 
 #[doc(hidden)]
 /// HTTP client connection
-pub struct H1Connection<T> {
+pub struct H1Connection<T>
+where
+    T: AsyncWrite + Unpin + 'static,
+{
     /// T should be `Unpin`
     io: Option<T>,
     created: time::Instant,
@@ -204,18 +207,11 @@ where
 }
 
 impl<T: AsyncRead + AsyncWrite + Unpin + 'static> AsyncRead for H1Connection<T> {
-    unsafe fn prepare_uninitialized_buffer(
-        &self,
-        buf: &mut [mem::MaybeUninit<u8>],
-    ) -> bool {
-        self.io.as_ref().unwrap().prepare_uninitialized_buffer(buf)
-    }
-
     fn poll_read(
         mut self: Pin<&mut Self>,
         cx: &mut Context<'_>,
-        buf: &mut [u8],
-    ) -> Poll<io::Result<usize>> {
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
         Pin::new(&mut self.io.as_mut().unwrap()).poll_read(cx, buf)
     }
 }
diff --git a/actix-http/src/client/h2proto.rs b/actix-http/src/client/h2proto.rs
index 3f9a981f4..0deb5c014 100644
--- a/actix-http/src/client/h2proto.rs
+++ b/actix-http/src/client/h2proto.rs
@@ -5,7 +5,6 @@ use std::time;
 use actix_codec::{AsyncRead, AsyncWrite};
 use bytes::Bytes;
 use futures_util::future::poll_fn;
-use futures_util::pin_mut;
 use h2::{
     client::{Builder, Connection, SendRequest},
     SendStream,
@@ -22,9 +21,10 @@ use super::config::ConnectorConfig;
 use super::connection::{ConnectionType, IoConnection};
 use super::error::SendRequestError;
 use super::pool::Acquired;
+use crate::client::connection::H2Connection;
 
 pub(crate) async fn send_request<T, B>(
-    mut io: SendRequest<Bytes>,
+    mut io: H2Connection,
     head: RequestHeadType,
     body: B,
     created: time::Instant,
@@ -35,6 +35,7 @@ where
     B: MessageBody,
 {
     trace!("Sending client request: {:?} {:?}", head, body.size());
+
     let head_req = head.as_ref().method == Method::HEAD;
     let length = body.size();
     let eof = matches!(
@@ -89,7 +90,7 @@ where
             CONNECTION | TRANSFER_ENCODING => continue, // http2 specific
             CONTENT_LENGTH if skip_len => continue,
             // DATE => has_date = true,
-            _ => (),
+            _ => {}
         }
         req.headers_mut().append(key, value.clone());
     }
@@ -129,7 +130,7 @@ async fn send_body<B: MessageBody>(
     mut send: SendStream<Bytes>,
 ) -> Result<(), SendRequestError> {
     let mut buf = None;
-    pin_mut!(body);
+    actix_rt::pin!(body);
     loop {
         if buf.is_none() {
             match poll_fn(|cx| body.as_mut().poll_next(cx)).await {
@@ -171,9 +172,9 @@ async fn send_body<B: MessageBody>(
     }
 }
 
-// release SendRequest object
+/// release SendRequest object
 fn release<T: AsyncRead + AsyncWrite + Unpin + 'static>(
-    io: SendRequest<Bytes>,
+    io: H2Connection,
     pool: Option<Acquired<T>>,
     created: time::Instant,
     close: bool,
diff --git a/actix-http/src/client/mod.rs b/actix-http/src/client/mod.rs
index dd1e9b25a..5f5e57edb 100644
--- a/actix-http/src/client/mod.rs
+++ b/actix-http/src/client/mod.rs
@@ -1,4 +1,5 @@
-//! Http client api
+//! HTTP client.
+
 use http::Uri;
 
 mod config;
@@ -9,6 +10,10 @@ mod h1proto;
 mod h2proto;
 mod pool;
 
+pub use actix_tls::connect::{
+    Connect as TcpConnect, ConnectError as TcpConnectError, Connection as TcpConnection,
+};
+
 pub use self::connection::Connection;
 pub use self::connector::Connector;
 pub use self::error::{ConnectError, FreezeRequestError, InvalidUrl, SendRequestError};
diff --git a/actix-http/src/client/pool.rs b/actix-http/src/client/pool.rs
index 08abc6277..3800696fa 100644
--- a/actix-http/src/client/pool.rs
+++ b/actix-http/src/client/pool.rs
@@ -1,26 +1,27 @@
-use std::cell::RefCell;
+//! Client connection pooling keyed on the authority part of the connection URI.
+
 use std::collections::VecDeque;
 use std::future::Future;
+use std::ops::Deref;
 use std::pin::Pin;
 use std::rc::Rc;
+use std::sync::Arc;
 use std::task::{Context, Poll};
 use std::time::{Duration, Instant};
+use std::{cell::RefCell, io};
 
 use actix_codec::{AsyncRead, AsyncWrite};
-use actix_rt::time::{delay_for, Delay};
+use actix_rt::time::{sleep, Sleep};
 use actix_service::Service;
-use actix_utils::{oneshot, task::LocalWaker};
-use bytes::Bytes;
-use futures_util::future::{poll_fn, FutureExt, LocalBoxFuture};
-use fxhash::FxHashMap;
-use h2::client::{Connection, SendRequest};
+use ahash::AHashMap;
+use futures_core::future::LocalBoxFuture;
 use http::uri::Authority;
-use indexmap::IndexSet;
 use pin_project::pin_project;
-use slab::Slab;
+use tokio::io::ReadBuf;
+use tokio::sync::{OwnedSemaphorePermit, Semaphore};
 
 use super::config::ConnectorConfig;
-use super::connection::{ConnectionType, IoConnection};
+use super::connection::{ConnectionType, H2Connection, IoConnection};
 use super::error::ConnectError;
 use super::h2proto::handshake;
 use super::Connect;
@@ -43,602 +44,635 @@ impl From<Authority> for Key {
     }
 }
 
-/// Connections pool
-pub(crate) struct ConnectionPool<T, Io: 'static>(Rc<RefCell<T>>, Rc<RefCell<Inner<Io>>>);
-
-impl<T, Io> ConnectionPool<T, Io>
+/// Connections pool for reuse Io type for certain [`http::uri::Authority`] as key.
+pub(crate) struct ConnectionPool<S, Io>
 where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-    T: Service<Request = Connect, Response = (Io, Protocol), Error = ConnectError>
-        + 'static,
+    Io: AsyncWrite + Unpin + 'static,
 {
-    pub(crate) fn new(connector: T, config: ConnectorConfig) -> Self {
-        let connector_rc = Rc::new(RefCell::new(connector));
-        let inner_rc = Rc::new(RefCell::new(Inner {
-            config,
-            acquired: 0,
-            waiters: Slab::new(),
-            waiters_queue: IndexSet::new(),
-            available: FxHashMap::default(),
-            waker: LocalWaker::new(),
-        }));
+    connector: Rc<S>,
+    inner: ConnectionPoolInner<Io>,
+}
 
-        // start support future
-        actix_rt::spawn(ConnectorPoolSupport {
-            connector: Rc::clone(&connector_rc),
-            inner: Rc::clone(&inner_rc),
-        });
+/// wrapper type for check the ref count of Rc.
+struct ConnectionPoolInner<Io>(Rc<ConnectionPoolInnerPriv<Io>>)
+where
+    Io: AsyncWrite + Unpin + 'static;
 
-        ConnectionPool(connector_rc, inner_rc)
+impl<Io> ConnectionPoolInner<Io>
+where
+    Io: AsyncWrite + Unpin + 'static,
+{
+    /// spawn a async for graceful shutdown h1 Io type with a timeout.
+    fn close(&self, conn: ConnectionType<Io>) {
+        if let Some(timeout) = self.config.disconnect_timeout {
+            if let ConnectionType::H1(io) = conn {
+                actix_rt::spawn(CloseConnection::new(io, timeout));
+            }
+        }
     }
 }
 
-impl<T, Io> Clone for ConnectionPool<T, Io>
+impl<Io> Clone for ConnectionPoolInner<Io>
 where
-    Io: 'static,
+    Io: AsyncWrite + Unpin + 'static,
 {
     fn clone(&self) -> Self {
-        ConnectionPool(self.0.clone(), self.1.clone())
+        Self(Rc::clone(&self.0))
     }
 }
 
-impl<T, Io> Drop for ConnectionPool<T, Io> {
-    fn drop(&mut self) {
-        // wake up the ConnectorPoolSupport when dropping so it can exit properly.
-        self.1.borrow().waker.wake();
-    }
-}
-
-impl<T, Io> Service for ConnectionPool<T, Io>
+impl<Io> Deref for ConnectionPoolInner<Io>
 where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-    T: Service<Request = Connect, Response = (Io, Protocol), Error = ConnectError>
-        + 'static,
+    Io: AsyncWrite + Unpin + 'static,
+{
+    type Target = ConnectionPoolInnerPriv<Io>;
+
+    fn deref(&self) -> &Self::Target {
+        &*self.0
+    }
+}
+
+impl<Io> Drop for ConnectionPoolInner<Io>
+where
+    Io: AsyncWrite + Unpin + 'static,
+{
+    fn drop(&mut self) {
+        // When strong count is one it means the pool is dropped
+        // remove and drop all Io types.
+        if Rc::strong_count(&self.0) == 1 {
+            self.permits.close();
+            std::mem::take(&mut *self.available.borrow_mut())
+                .into_iter()
+                .for_each(|(_, conns)| {
+                    conns.into_iter().for_each(|pooled| self.close(pooled.conn))
+                });
+        }
+    }
+}
+
+struct ConnectionPoolInnerPriv<Io>
+where
+    Io: AsyncWrite + Unpin + 'static,
+{
+    config: ConnectorConfig,
+    available: RefCell<AHashMap<Key, VecDeque<PooledConnection<Io>>>>,
+    permits: Arc<Semaphore>,
+}
+
+impl<S, Io> ConnectionPool<S, Io>
+where
+    Io: AsyncWrite + Unpin + 'static,
+{
+    /// Construct a new connection pool.
+    ///
+    /// [`super::config::ConnectorConfig`]'s `limit` is used as the max permits allowed for
+    /// in-flight connections.
+    ///
+    /// The pool can only have equal to `limit` amount of requests spawning/using Io type
+    /// concurrently.
+    ///
+    /// Any requests beyond limit would be wait in fifo order and get notified in async manner
+    /// by [`tokio::sync::Semaphore`]
+    pub(crate) fn new(connector: S, config: ConnectorConfig) -> Self {
+        let permits = Arc::new(Semaphore::new(config.limit));
+        let available = RefCell::new(AHashMap::default());
+        let connector = Rc::new(connector);
+
+        let inner = ConnectionPoolInner(Rc::new(ConnectionPoolInnerPriv {
+            config,
+            available,
+            permits,
+        }));
+
+        Self { connector, inner }
+    }
+}
+
+impl<S, Io> Clone for ConnectionPool<S, Io>
+where
+    Io: AsyncWrite + Unpin + 'static,
+{
+    fn clone(&self) -> Self {
+        Self {
+            connector: self.connector.clone(),
+            inner: self.inner.clone(),
+        }
+    }
+}
+
+impl<S, Io> Service<Connect> for ConnectionPool<S, Io>
+where
+    S: Service<Connect, Response = (Io, Protocol), Error = ConnectError> + 'static,
+    Io: AsyncRead + AsyncWrite + Unpin + 'static,
 {
-    type Request = Connect;
     type Response = IoConnection<Io>;
     type Error = ConnectError;
     type Future = LocalBoxFuture<'static, Result<IoConnection<Io>, ConnectError>>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.0.poll_ready(cx)
-    }
+    actix_service::forward_ready!(connector);
 
-    fn call(&mut self, req: Connect) -> Self::Future {
-        let mut connector = self.0.clone();
-        let inner = self.1.clone();
+    fn call(&self, req: Connect) -> Self::Future {
+        let connector = self.connector.clone();
+        let inner = self.inner.clone();
 
-        let fut = async move {
+        Box::pin(async move {
             let key = if let Some(authority) = req.uri.authority() {
                 authority.clone().into()
             } else {
                 return Err(ConnectError::Unresolved);
             };
 
-            // acquire connection
-            match poll_fn(|cx| Poll::Ready(inner.borrow_mut().acquire(&key, cx))).await {
-                Acquire::Acquired(io, created) => {
-                    // use existing connection
-                    Ok(IoConnection::new(
-                        io,
-                        created,
-                        Some(Acquired(key, Some(inner))),
-                    ))
-                }
-                Acquire::Available => {
-                    // open tcp connection
+            // acquire an owned permit and carry it with connection
+            let permit = inner.permits.clone().acquire_owned().await.map_err(|_| {
+                ConnectError::Io(io::Error::new(
+                    io::ErrorKind::Other,
+                    "failed to acquire semaphore on client connection pool",
+                ))
+            })?;
+
+            let conn = {
+                let mut conn = None;
+
+                // check if there is idle connection for given key.
+                let mut map = inner.available.borrow_mut();
+
+                if let Some(conns) = map.get_mut(&key) {
+                    let now = Instant::now();
+
+                    while let Some(mut c) = conns.pop_front() {
+                        let config = &inner.config;
+                        let idle_dur = now - c.used;
+                        let age = now - c.created;
+                        let conn_ineligible = idle_dur > config.conn_keep_alive
+                            || age > config.conn_lifetime;
+
+                        if conn_ineligible {
+                            // drop connections that are too old
+                            inner.close(c.conn);
+                        } else {
+                            // check if the connection is still usable
+                            if let ConnectionType::H1(ref mut io) = c.conn {
+                                let check = ConnectionCheckFuture { io };
+                                match check.await {
+                                    ConnectionState::Tainted => {
+                                        inner.close(c.conn);
+                                        continue;
+                                    }
+                                    ConnectionState::Skip => continue,
+                                    ConnectionState::Live => conn = Some(c),
+                                }
+                            } else {
+                                conn = Some(c);
+                            }
+
+                            break;
+                        }
+                    }
+                };
+
+                conn
+            };
+
+            // construct acquired. It's used to put Io type back to pool/ close the Io type.
+            // permit is carried with the whole lifecycle of Acquired.
+            let acquired = Some(Acquired { key, inner, permit });
+
+            // match the connection and spawn new one if did not get anything.
+            match conn {
+                Some(conn) => Ok(IoConnection::new(conn.conn, conn.created, acquired)),
+                None => {
                     let (io, proto) = connector.call(req).await?;
 
-                    let config = inner.borrow().config.clone();
-
-                    let guard = OpenGuard::new(key, inner);
-
                     if proto == Protocol::Http1 {
                         Ok(IoConnection::new(
                             ConnectionType::H1(io),
                             Instant::now(),
-                            Some(guard.consume()),
+                            acquired,
                         ))
                     } else {
-                        let (snd, connection) = handshake(io, &config).await?;
-                        actix_rt::spawn(connection.map(|_| ()));
+                        let config = &acquired.as_ref().unwrap().inner.config;
+                        let (sender, connection) = handshake(io, config).await?;
                         Ok(IoConnection::new(
-                            ConnectionType::H2(snd),
+                            ConnectionType::H2(H2Connection::new(sender, connection)),
                             Instant::now(),
-                            Some(guard.consume()),
+                            acquired,
                         ))
                     }
                 }
-                _ => {
-                    // connection is not available, wait
-                    let (rx, token) = inner.borrow_mut().wait_for(req);
-
-                    let guard = WaiterGuard::new(key, token, inner);
-                    let res = match rx.await {
-                        Err(_) => Err(ConnectError::Disconnected),
-                        Ok(res) => res,
-                    };
-                    guard.consume();
-                    res
-                }
             }
-        };
-
-        fut.boxed_local()
-    }
-}
-
-struct WaiterGuard<Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    key: Key,
-    token: usize,
-    inner: Option<Rc<RefCell<Inner<Io>>>>,
-}
-
-impl<Io> WaiterGuard<Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    fn new(key: Key, token: usize, inner: Rc<RefCell<Inner<Io>>>) -> Self {
-        Self {
-            key,
-            token,
-            inner: Some(inner),
-        }
-    }
-
-    fn consume(mut self) {
-        let _ = self.inner.take();
-    }
-}
-
-impl<Io> Drop for WaiterGuard<Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    fn drop(&mut self) {
-        if let Some(i) = self.inner.take() {
-            let mut inner = i.as_ref().borrow_mut();
-            inner.release_waiter(&self.key, self.token);
-            inner.check_availability();
-        }
-    }
-}
-
-struct OpenGuard<Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    key: Key,
-    inner: Option<Rc<RefCell<Inner<Io>>>>,
-}
-
-impl<Io> OpenGuard<Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    fn new(key: Key, inner: Rc<RefCell<Inner<Io>>>) -> Self {
-        Self {
-            key,
-            inner: Some(inner),
-        }
-    }
-
-    fn consume(mut self) -> Acquired<Io> {
-        Acquired(self.key.clone(), self.inner.take())
-    }
-}
-
-impl<Io> Drop for OpenGuard<Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    fn drop(&mut self) {
-        if let Some(i) = self.inner.take() {
-            let mut inner = i.as_ref().borrow_mut();
-            inner.release();
-            inner.check_availability();
-        }
-    }
-}
-
-enum Acquire<T> {
-    Acquired(ConnectionType<T>, Instant),
-    Available,
-    NotAvailable,
-}
-
-struct AvailableConnection<Io> {
-    io: ConnectionType<Io>,
-    used: Instant,
-    created: Instant,
-}
-
-pub(crate) struct Inner<Io> {
-    config: ConnectorConfig,
-    acquired: usize,
-    available: FxHashMap<Key, VecDeque<AvailableConnection<Io>>>,
-    waiters: Slab<
-        Option<(
-            Connect,
-            oneshot::Sender<Result<IoConnection<Io>, ConnectError>>,
-        )>,
-    >,
-    waiters_queue: IndexSet<(Key, usize)>,
-    waker: LocalWaker,
-}
-
-impl<Io> Inner<Io> {
-    fn reserve(&mut self) {
-        self.acquired += 1;
-    }
-
-    fn release(&mut self) {
-        self.acquired -= 1;
-    }
-
-    fn release_waiter(&mut self, key: &Key, token: usize) {
-        self.waiters.remove(token);
-        let _ = self.waiters_queue.shift_remove(&(key.clone(), token));
-    }
-}
-
-impl<Io> Inner<Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    /// connection is not available, wait
-    fn wait_for(
-        &mut self,
-        connect: Connect,
-    ) -> (
-        oneshot::Receiver<Result<IoConnection<Io>, ConnectError>>,
-        usize,
-    ) {
-        let (tx, rx) = oneshot::channel();
-
-        let key: Key = connect.uri.authority().unwrap().clone().into();
-        let entry = self.waiters.vacant_entry();
-        let token = entry.key();
-        entry.insert(Some((connect, tx)));
-        assert!(self.waiters_queue.insert((key, token)));
-
-        (rx, token)
-    }
-
-    fn acquire(&mut self, key: &Key, cx: &mut Context<'_>) -> Acquire<Io> {
-        // check limits
-        if self.config.limit > 0 && self.acquired >= self.config.limit {
-            return Acquire::NotAvailable;
-        }
-
-        self.reserve();
-
-        // check if open connection is available
-        // cleanup stale connections at the same time
-        if let Some(ref mut connections) = self.available.get_mut(key) {
-            let now = Instant::now();
-            while let Some(conn) = connections.pop_back() {
-                // check if it still usable
-                if (now - conn.used) > self.config.conn_keep_alive
-                    || (now - conn.created) > self.config.conn_lifetime
-                {
-                    if let Some(timeout) = self.config.disconnect_timeout {
-                        if let ConnectionType::H1(io) = conn.io {
-                            actix_rt::spawn(CloseConnection::new(io, timeout))
-                        }
-                    }
-                } else {
-                    let mut io = conn.io;
-                    let mut buf = [0; 2];
-                    if let ConnectionType::H1(ref mut s) = io {
-                        match Pin::new(s).poll_read(cx, &mut buf) {
-                            Poll::Pending => (),
-                            Poll::Ready(Ok(n)) if n > 0 => {
-                                if let Some(timeout) = self.config.disconnect_timeout {
-                                    if let ConnectionType::H1(io) = io {
-                                        actix_rt::spawn(CloseConnection::new(
-                                            io, timeout,
-                                        ))
-                                    }
-                                }
-                                continue;
-                            }
-                            _ => continue,
-                        }
-                    }
-                    return Acquire::Acquired(io, conn.created);
-                }
-            }
-        }
-        Acquire::Available
-    }
-
-    fn release_conn(&mut self, key: &Key, io: ConnectionType<Io>, created: Instant) {
-        self.acquired -= 1;
-        self.available
-            .entry(key.clone())
-            .or_insert_with(VecDeque::new)
-            .push_back(AvailableConnection {
-                io,
-                created,
-                used: Instant::now(),
-            });
-        self.check_availability();
-    }
-
-    fn release_close(&mut self, io: ConnectionType<Io>) {
-        self.acquired -= 1;
-        if let Some(timeout) = self.config.disconnect_timeout {
-            if let ConnectionType::H1(io) = io {
-                actix_rt::spawn(CloseConnection::new(io, timeout))
-            }
-        }
-        self.check_availability();
-    }
-
-    fn check_availability(&self) {
-        if !self.waiters_queue.is_empty() && self.acquired < self.config.limit {
-            self.waker.wake();
-        }
-    }
-}
-
-struct CloseConnection<T> {
-    io: T,
-    timeout: Delay,
-}
-
-impl<T> CloseConnection<T>
-where
-    T: AsyncWrite + Unpin,
-{
-    fn new(io: T, timeout: Duration) -> Self {
-        CloseConnection {
-            io,
-            timeout: delay_for(timeout),
-        }
-    }
-}
-
-impl<T> Future for CloseConnection<T>
-where
-    T: AsyncWrite + Unpin,
-{
-    type Output = ();
-
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<()> {
-        let this = self.get_mut();
-
-        match Pin::new(&mut this.timeout).poll(cx) {
-            Poll::Ready(_) => Poll::Ready(()),
-            Poll::Pending => match Pin::new(&mut this.io).poll_shutdown(cx) {
-                Poll::Ready(_) => Poll::Ready(()),
-                Poll::Pending => Poll::Pending,
-            },
-        }
-    }
-}
-
-#[pin_project]
-struct ConnectorPoolSupport<T, Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    connector: T,
-    inner: Rc<RefCell<Inner<Io>>>,
-}
-
-impl<T, Io> Future for ConnectorPoolSupport<T, Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-    T: Service<Request = Connect, Response = (Io, Protocol), Error = ConnectError>,
-    T::Future: 'static,
-{
-    type Output = ();
-
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.project();
-
-        if Rc::strong_count(this.inner) == 1 {
-            // If we are last copy of Inner<Io> it means the ConnectionPool is already gone
-            // and we are safe to exit.
-            return Poll::Ready(());
-        }
-
-        let mut inner = this.inner.borrow_mut();
-        inner.waker.register(cx.waker());
-
-        // check waiters
-        loop {
-            let (key, token) = {
-                if let Some((key, token)) = inner.waiters_queue.get_index(0) {
-                    (key.clone(), *token)
-                } else {
-                    break;
-                }
-            };
-            if inner.waiters.get(token).unwrap().is_none() {
-                continue;
-            }
-
-            match inner.acquire(&key, cx) {
-                Acquire::NotAvailable => break,
-                Acquire::Acquired(io, created) => {
-                    let tx = inner.waiters.get_mut(token).unwrap().take().unwrap().1;
-                    if let Err(conn) = tx.send(Ok(IoConnection::new(
-                        io,
-                        created,
-                        Some(Acquired(key.clone(), Some(this.inner.clone()))),
-                    ))) {
-                        let (io, created) = conn.unwrap().into_inner();
-                        inner.release_conn(&key, io, created);
-                    }
-                }
-                Acquire::Available => {
-                    let (connect, tx) =
-                        inner.waiters.get_mut(token).unwrap().take().unwrap();
-                    OpenWaitingConnection::spawn(
-                        key.clone(),
-                        tx,
-                        this.inner.clone(),
-                        this.connector.call(connect),
-                        inner.config.clone(),
-                    );
-                }
-            }
-            let _ = inner.waiters_queue.swap_remove_index(0);
-        }
-
-        Poll::Pending
-    }
-}
-
-#[pin_project::pin_project(PinnedDrop)]
-struct OpenWaitingConnection<F, Io>
-where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    #[pin]
-    fut: F,
-    key: Key,
-    h2: Option<
-        LocalBoxFuture<
-            'static,
-            Result<(SendRequest<Bytes>, Connection<Io, Bytes>), h2::Error>,
-        >,
-    >,
-    rx: Option<oneshot::Sender<Result<IoConnection<Io>, ConnectError>>>,
-    inner: Option<Rc<RefCell<Inner<Io>>>>,
-    config: ConnectorConfig,
-}
-
-impl<F, Io> OpenWaitingConnection<F, Io>
-where
-    F: Future<Output = Result<(Io, Protocol), ConnectError>> + 'static,
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
-{
-    fn spawn(
-        key: Key,
-        rx: oneshot::Sender<Result<IoConnection<Io>, ConnectError>>,
-        inner: Rc<RefCell<Inner<Io>>>,
-        fut: F,
-        config: ConnectorConfig,
-    ) {
-        actix_rt::spawn(OpenWaitingConnection {
-            key,
-            fut,
-            h2: None,
-            rx: Some(rx),
-            inner: Some(inner),
-            config,
         })
     }
 }
 
-#[pin_project::pinned_drop]
-impl<F, Io> PinnedDrop for OpenWaitingConnection<F, Io>
+/// Type for check the connection and determine if it's usable.
+struct ConnectionCheckFuture<'a, Io> {
+    io: &'a mut Io,
+}
+
+enum ConnectionState {
+    /// IO is pending and a new request would wake it.
+    Live,
+
+    /// IO unexpectedly has unread data and should be dropped.
+    Tainted,
+
+    /// IO should be skipped but not dropped.
+    Skip,
+}
+
+impl<Io> Future for ConnectionCheckFuture<'_, Io>
 where
-    Io: AsyncRead + AsyncWrite + Unpin + 'static,
+    Io: AsyncRead + Unpin,
 {
-    fn drop(self: Pin<&mut Self>) {
-        if let Some(inner) = self.project().inner.take() {
-            let mut inner = inner.as_ref().borrow_mut();
-            inner.release();
-            inner.check_availability();
+    type Output = ConnectionState;
+
+    // this future is only used to get access to Context.
+    // It should never return Poll::Pending.
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.get_mut();
+        let mut buf = [0; 2];
+        let mut read_buf = ReadBuf::new(&mut buf);
+
+        let state = match Pin::new(&mut this.io).poll_read(cx, &mut read_buf) {
+            Poll::Ready(Ok(())) if !read_buf.filled().is_empty() => {
+                ConnectionState::Tainted
+            }
+
+            Poll::Pending => ConnectionState::Live,
+            _ => ConnectionState::Skip,
+        };
+
+        Poll::Ready(state)
+    }
+}
+
+struct PooledConnection<Io> {
+    conn: ConnectionType<Io>,
+    used: Instant,
+    created: Instant,
+}
+
+#[pin_project]
+struct CloseConnection<Io> {
+    io: Io,
+    #[pin]
+    timeout: Sleep,
+}
+
+impl<Io> CloseConnection<Io>
+where
+    Io: AsyncWrite + Unpin,
+{
+    fn new(io: Io, timeout: Duration) -> Self {
+        CloseConnection {
+            io,
+            timeout: sleep(timeout),
         }
     }
 }
 
-impl<F, Io> Future for OpenWaitingConnection<F, Io>
+impl<Io> Future for CloseConnection<Io>
 where
-    F: Future<Output = Result<(Io, Protocol), ConnectError>>,
-    Io: AsyncRead + AsyncWrite + Unpin,
+    Io: AsyncWrite + Unpin,
 {
     type Output = ();
 
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.as_mut().project();
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<()> {
+        let this = self.project();
 
-        if let Some(ref mut h2) = this.h2 {
-            return match Pin::new(h2).poll(cx) {
-                Poll::Ready(Ok((snd, connection))) => {
-                    actix_rt::spawn(connection.map(|_| ()));
-                    let rx = this.rx.take().unwrap();
-                    let _ = rx.send(Ok(IoConnection::new(
-                        ConnectionType::H2(snd),
-                        Instant::now(),
-                        Some(Acquired(this.key.clone(), this.inner.take())),
-                    )));
-                    Poll::Ready(())
-                }
-                Poll::Pending => Poll::Pending,
-                Poll::Ready(Err(err)) => {
-                    let _ = this.inner.take();
-                    if let Some(rx) = this.rx.take() {
-                        let _ = rx.send(Err(ConnectError::H2(err)));
-                    }
-                    Poll::Ready(())
-                }
-            };
-        }
-
-        match this.fut.poll(cx) {
-            Poll::Ready(Err(err)) => {
-                let _ = this.inner.take();
-                if let Some(rx) = this.rx.take() {
-                    let _ = rx.send(Err(err));
-                }
-                Poll::Ready(())
-            }
-            Poll::Ready(Ok((io, proto))) => {
-                if proto == Protocol::Http1 {
-                    let rx = this.rx.take().unwrap();
-                    let _ = rx.send(Ok(IoConnection::new(
-                        ConnectionType::H1(io),
-                        Instant::now(),
-                        Some(Acquired(this.key.clone(), this.inner.take())),
-                    )));
-                    Poll::Ready(())
-                } else {
-                    *this.h2 = Some(handshake(io, this.config).boxed_local());
-                    self.poll(cx)
-                }
-            }
-            Poll::Pending => Poll::Pending,
+        match this.timeout.poll(cx) {
+            Poll::Ready(_) => Poll::Ready(()),
+            Poll::Pending => Pin::new(this.io).poll_shutdown(cx).map(|_| ()),
         }
     }
 }
 
-pub(crate) struct Acquired<T>(Key, Option<Rc<RefCell<Inner<T>>>>);
-
-impl<T> Acquired<T>
+pub(crate) struct Acquired<Io>
 where
-    T: AsyncRead + AsyncWrite + Unpin + 'static,
+    Io: AsyncWrite + Unpin + 'static,
 {
-    pub(crate) fn close(&mut self, conn: IoConnection<T>) {
-        if let Some(inner) = self.1.take() {
-            let (io, _) = conn.into_inner();
-            inner.as_ref().borrow_mut().release_close(io);
-        }
+    key: Key,
+    inner: ConnectionPoolInner<Io>,
+    permit: OwnedSemaphorePermit,
+}
+
+impl<Io> Acquired<Io>
+where
+    Io: AsyncRead + AsyncWrite + Unpin + 'static,
+{
+    /// Close the IO.
+    pub(crate) fn close(&mut self, conn: IoConnection<Io>) {
+        let (conn, _) = conn.into_inner();
+        self.inner.close(conn);
     }
-    pub(crate) fn release(&mut self, conn: IoConnection<T>) {
-        if let Some(inner) = self.1.take() {
-            let (io, created) = conn.into_inner();
-            inner
-                .as_ref()
-                .borrow_mut()
-                .release_conn(&self.0, io, created);
-        }
+
+    /// Release IO back into pool.
+    pub(crate) fn release(&mut self, conn: IoConnection<Io>) {
+        let (io, created) = conn.into_inner();
+        let Acquired { key, inner, .. } = self;
+
+        inner
+            .available
+            .borrow_mut()
+            .entry(key.clone())
+            .or_insert_with(VecDeque::new)
+            .push_back(PooledConnection {
+                conn: io,
+                created,
+                used: Instant::now(),
+            });
+
+        let _ = &mut self.permit;
     }
 }
 
-impl<T> Drop for Acquired<T> {
-    fn drop(&mut self) {
-        if let Some(inner) = self.1.take() {
-            inner.as_ref().borrow_mut().release();
+#[cfg(test)]
+mod test {
+    use std::{cell::Cell, io};
+
+    use http::Uri;
+
+    use super::*;
+    use crate::client::connection::IoConnection;
+
+    /// A stream type that always returns pending on async read.
+    ///
+    /// Mocks an idle TCP stream that is ready to be used for client connections.
+    struct TestStream(Rc<Cell<usize>>);
+
+    impl Drop for TestStream {
+        fn drop(&mut self) {
+            self.0.set(self.0.get() - 1);
         }
     }
+
+    impl AsyncRead for TestStream {
+        fn poll_read(
+            self: Pin<&mut Self>,
+            _: &mut Context<'_>,
+            _: &mut ReadBuf<'_>,
+        ) -> Poll<io::Result<()>> {
+            Poll::Pending
+        }
+    }
+
+    impl AsyncWrite for TestStream {
+        fn poll_write(
+            self: Pin<&mut Self>,
+            _: &mut Context<'_>,
+            _: &[u8],
+        ) -> Poll<io::Result<usize>> {
+            unimplemented!()
+        }
+
+        fn poll_flush(
+            self: Pin<&mut Self>,
+            _: &mut Context<'_>,
+        ) -> Poll<io::Result<()>> {
+            unimplemented!()
+        }
+
+        fn poll_shutdown(
+            self: Pin<&mut Self>,
+            _: &mut Context<'_>,
+        ) -> Poll<io::Result<()>> {
+            Poll::Ready(Ok(()))
+        }
+    }
+
+    struct TestPoolConnector {
+        generated: Rc<Cell<usize>>,
+    }
+
+    impl Service<Connect> for TestPoolConnector {
+        type Response = (TestStream, Protocol);
+        type Error = ConnectError;
+        type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
+
+        actix_service::always_ready!();
+
+        fn call(&self, _: Connect) -> Self::Future {
+            self.generated.set(self.generated.get() + 1);
+            let generated = self.generated.clone();
+            Box::pin(async { Ok((TestStream(generated), Protocol::Http1)) })
+        }
+    }
+
+    fn release<T>(conn: IoConnection<T>)
+    where
+        T: AsyncRead + AsyncWrite + Unpin + 'static,
+    {
+        let (conn, created, mut acquired) = conn.into_parts();
+        acquired.release(IoConnection::new(conn, created, None));
+    }
+
+    #[actix_rt::test]
+    async fn test_pool_limit() {
+        let connector = TestPoolConnector {
+            generated: Rc::new(Cell::new(0)),
+        };
+
+        let config = ConnectorConfig {
+            limit: 1,
+            ..Default::default()
+        };
+
+        let pool = super::ConnectionPool::new(connector, config);
+
+        let req = Connect {
+            uri: Uri::from_static("http://localhost"),
+            addr: None,
+        };
+
+        let conn = pool.call(req.clone()).await.unwrap();
+
+        let waiting = Rc::new(Cell::new(true));
+
+        let waiting_clone = waiting.clone();
+        actix_rt::spawn(async move {
+            actix_rt::time::sleep(Duration::from_millis(100)).await;
+            waiting_clone.set(false);
+            drop(conn);
+        });
+
+        assert!(waiting.get());
+
+        let now = Instant::now();
+        let conn = pool.call(req).await.unwrap();
+
+        release(conn);
+        assert!(!waiting.get());
+        assert!(now.elapsed() >= Duration::from_millis(100));
+    }
+
+    #[actix_rt::test]
+    async fn test_pool_keep_alive() {
+        let generated = Rc::new(Cell::new(0));
+        let generated_clone = generated.clone();
+
+        let connector = TestPoolConnector { generated };
+
+        let config = ConnectorConfig {
+            conn_keep_alive: Duration::from_secs(1),
+            ..Default::default()
+        };
+
+        let pool = super::ConnectionPool::new(connector, config);
+
+        let req = Connect {
+            uri: Uri::from_static("http://localhost"),
+            addr: None,
+        };
+
+        let conn = pool.call(req.clone()).await.unwrap();
+        assert_eq!(1, generated_clone.get());
+        release(conn);
+
+        let conn = pool.call(req.clone()).await.unwrap();
+        assert_eq!(1, generated_clone.get());
+        release(conn);
+
+        actix_rt::time::sleep(Duration::from_millis(1500)).await;
+        actix_rt::task::yield_now().await;
+
+        let conn = pool.call(req).await.unwrap();
+        // Note: spawned recycle connection is not ran yet.
+        // This is tokio current thread runtime specific behavior.
+        assert_eq!(2, generated_clone.get());
+
+        // yield task so the old connection is properly dropped.
+        actix_rt::task::yield_now().await;
+        assert_eq!(1, generated_clone.get());
+
+        release(conn);
+    }
+
+    #[actix_rt::test]
+    async fn test_pool_lifetime() {
+        let generated = Rc::new(Cell::new(0));
+        let generated_clone = generated.clone();
+
+        let connector = TestPoolConnector { generated };
+
+        let config = ConnectorConfig {
+            conn_lifetime: Duration::from_secs(1),
+            ..Default::default()
+        };
+
+        let pool = super::ConnectionPool::new(connector, config);
+
+        let req = Connect {
+            uri: Uri::from_static("http://localhost"),
+            addr: None,
+        };
+
+        let conn = pool.call(req.clone()).await.unwrap();
+        assert_eq!(1, generated_clone.get());
+        release(conn);
+
+        let conn = pool.call(req.clone()).await.unwrap();
+        assert_eq!(1, generated_clone.get());
+        release(conn);
+
+        actix_rt::time::sleep(Duration::from_millis(1500)).await;
+        actix_rt::task::yield_now().await;
+
+        let conn = pool.call(req).await.unwrap();
+        // Note: spawned recycle connection is not ran yet.
+        // This is tokio current thread runtime specific behavior.
+        assert_eq!(2, generated_clone.get());
+
+        // yield task so the old connection is properly dropped.
+        actix_rt::task::yield_now().await;
+        assert_eq!(1, generated_clone.get());
+
+        release(conn);
+    }
+
+    #[actix_rt::test]
+    async fn test_pool_authority_key() {
+        let generated = Rc::new(Cell::new(0));
+        let generated_clone = generated.clone();
+
+        let connector = TestPoolConnector { generated };
+
+        let config = ConnectorConfig::default();
+
+        let pool = super::ConnectionPool::new(connector, config);
+
+        let req = Connect {
+            uri: Uri::from_static("https://crates.io"),
+            addr: None,
+        };
+
+        let conn = pool.call(req.clone()).await.unwrap();
+        assert_eq!(1, generated_clone.get());
+        release(conn);
+
+        let conn = pool.call(req).await.unwrap();
+        assert_eq!(1, generated_clone.get());
+        release(conn);
+
+        let req = Connect {
+            uri: Uri::from_static("https://google.com"),
+            addr: None,
+        };
+
+        let conn = pool.call(req.clone()).await.unwrap();
+        assert_eq!(2, generated_clone.get());
+        release(conn);
+        let conn = pool.call(req).await.unwrap();
+        assert_eq!(2, generated_clone.get());
+        release(conn);
+    }
+
+    #[actix_rt::test]
+    async fn test_pool_drop() {
+        let generated = Rc::new(Cell::new(0));
+        let generated_clone = generated.clone();
+
+        let connector = TestPoolConnector { generated };
+
+        let config = ConnectorConfig::default();
+
+        let pool = Rc::new(super::ConnectionPool::new(connector, config));
+
+        let req = Connect {
+            uri: Uri::from_static("https://crates.io"),
+            addr: None,
+        };
+
+        let conn = pool.call(req.clone()).await.unwrap();
+        assert_eq!(1, generated_clone.get());
+        release(conn);
+
+        let req = Connect {
+            uri: Uri::from_static("https://google.com"),
+            addr: None,
+        };
+        let conn = pool.call(req.clone()).await.unwrap();
+        assert_eq!(2, generated_clone.get());
+        release(conn);
+
+        let clone1 = pool.clone();
+        let clone2 = clone1.clone();
+
+        drop(clone2);
+        for _ in 0..2 {
+            actix_rt::task::yield_now().await;
+        }
+        assert_eq!(2, generated_clone.get());
+
+        drop(clone1);
+        for _ in 0..2 {
+            actix_rt::task::yield_now().await;
+        }
+        assert_eq!(2, generated_clone.get());
+
+        drop(pool);
+        for _ in 0..2 {
+            actix_rt::task::yield_now().await;
+        }
+        assert_eq!(0, generated_clone.get());
+    }
 }
diff --git a/actix-http/src/cloneable.rs b/actix-http/src/cloneable.rs
deleted file mode 100644
index b64c299fc..000000000
--- a/actix-http/src/cloneable.rs
+++ /dev/null
@@ -1,40 +0,0 @@
-use std::cell::RefCell;
-use std::rc::Rc;
-use std::task::{Context, Poll};
-
-use actix_service::Service;
-
-#[doc(hidden)]
-/// Service that allows to turn non-clone service to a service with `Clone` impl
-///
-/// # Panics
-/// CloneableService might panic with some creative use of thread local storage.
-/// See https://github.com/actix/actix-web/issues/1295 for example
-pub(crate) struct CloneableService<T: Service>(Rc<RefCell<T>>);
-
-impl<T: Service> CloneableService<T> {
-    pub(crate) fn new(service: T) -> Self {
-        Self(Rc::new(RefCell::new(service)))
-    }
-}
-
-impl<T: Service> Clone for CloneableService<T> {
-    fn clone(&self) -> Self {
-        Self(self.0.clone())
-    }
-}
-
-impl<T: Service> Service for CloneableService<T> {
-    type Request = T::Request;
-    type Response = T::Response;
-    type Error = T::Error;
-    type Future = T::Future;
-
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.0.borrow_mut().poll_ready(cx)
-    }
-
-    fn call(&mut self, req: T::Request) -> Self::Future {
-        self.0.borrow_mut().call(req)
-    }
-}
diff --git a/actix-http/src/config.rs b/actix-http/src/config.rs
index b314d4c99..9f84b8694 100644
--- a/actix-http/src/config.rs
+++ b/actix-http/src/config.rs
@@ -4,12 +4,14 @@ use std::rc::Rc;
 use std::time::Duration;
 use std::{fmt, net};
 
-use actix_rt::time::{delay_for, delay_until, Delay, Instant};
+use actix_rt::{
+    task::JoinHandle,
+    time::{interval, sleep_until, Instant, Sleep},
+};
 use bytes::BytesMut;
-use futures_util::{future, FutureExt};
 use time::OffsetDateTime;
 
-// "Sun, 06 Nov 1994 08:49:37 GMT".len()
+/// "Sun, 06 Nov 1994 08:49:37 GMT".len()
 const DATE_VALUE_LENGTH: usize = 29;
 
 #[derive(Debug, PartialEq, Clone, Copy)]
@@ -49,7 +51,7 @@ struct Inner {
     ka_enabled: bool,
     secure: bool,
     local_addr: Option<std::net::SocketAddr>,
-    timer: DateService,
+    date_service: DateService,
 }
 
 impl Clone for ServiceConfig {
@@ -91,41 +93,41 @@ impl ServiceConfig {
             client_disconnect,
             secure,
             local_addr,
-            timer: DateService::new(),
+            date_service: DateService::new(),
         }))
     }
 
+    /// Returns true if connection is secure (HTTPS)
     #[inline]
-    /// Returns true if connection is secure(https)
     pub fn secure(&self) -> bool {
         self.0.secure
     }
 
-    #[inline]
     /// Returns the local address that this server is bound to.
+    #[inline]
     pub fn local_addr(&self) -> Option<net::SocketAddr> {
         self.0.local_addr
     }
 
-    #[inline]
     /// Keep alive duration if configured.
+    #[inline]
     pub fn keep_alive(&self) -> Option<Duration> {
         self.0.keep_alive
     }
 
-    #[inline]
     /// Return state of connection keep-alive functionality
+    #[inline]
     pub fn keep_alive_enabled(&self) -> bool {
         self.0.ka_enabled
     }
 
-    #[inline]
     /// Client timeout for first request.
-    pub fn client_timer(&self) -> Option<Delay> {
+    #[inline]
+    pub fn client_timer(&self) -> Option<Sleep> {
         let delay_time = self.0.client_timeout;
         if delay_time != 0 {
-            Some(delay_until(
-                self.0.timer.now() + Duration::from_millis(delay_time),
+            Some(sleep_until(
+                self.0.date_service.now() + Duration::from_millis(delay_time),
             ))
         } else {
             None
@@ -136,7 +138,7 @@ impl ServiceConfig {
     pub fn client_timer_expire(&self) -> Option<Instant> {
         let delay = self.0.client_timeout;
         if delay != 0 {
-            Some(self.0.timer.now() + Duration::from_millis(delay))
+            Some(self.0.date_service.now() + Duration::from_millis(delay))
         } else {
             None
         }
@@ -146,7 +148,7 @@ impl ServiceConfig {
     pub fn client_disconnect_timer(&self) -> Option<Instant> {
         let delay = self.0.client_disconnect;
         if delay != 0 {
-            Some(self.0.timer.now() + Duration::from_millis(delay))
+            Some(self.0.date_service.now() + Duration::from_millis(delay))
         } else {
             None
         }
@@ -154,9 +156,9 @@ impl ServiceConfig {
 
     #[inline]
     /// Return keep-alive timer delay is configured.
-    pub fn keep_alive_timer(&self) -> Option<Delay> {
+    pub fn keep_alive_timer(&self) -> Option<Sleep> {
         if let Some(ka) = self.0.keep_alive {
-            Some(delay_until(self.0.timer.now() + ka))
+            Some(sleep_until(self.0.date_service.now() + ka))
         } else {
             None
         }
@@ -165,7 +167,7 @@ impl ServiceConfig {
     /// Keep-alive expire time
     pub fn keep_alive_expire(&self) -> Option<Instant> {
         if let Some(ka) = self.0.keep_alive {
-            Some(self.0.timer.now() + ka)
+            Some(self.0.date_service.now() + ka)
         } else {
             None
         }
@@ -173,7 +175,7 @@ impl ServiceConfig {
 
     #[inline]
     pub(crate) fn now(&self) -> Instant {
-        self.0.timer.now()
+        self.0.date_service.now()
     }
 
     #[doc(hidden)]
@@ -181,7 +183,7 @@ impl ServiceConfig {
         let mut buf: [u8; 39] = [0; 39];
         buf[..6].copy_from_slice(b"date: ");
         self.0
-            .timer
+            .date_service
             .set_date(|date| buf[6..35].copy_from_slice(&date.bytes));
         buf[35..].copy_from_slice(b"\r\n\r\n");
         dst.extend_from_slice(&buf);
@@ -189,7 +191,7 @@ impl ServiceConfig {
 
     pub(crate) fn set_date_header(&self, dst: &mut BytesMut) {
         self.0
-            .timer
+            .date_service
             .set_date(|date| dst.extend_from_slice(&date.bytes));
     }
 }
@@ -230,57 +232,103 @@ impl fmt::Write for Date {
     }
 }
 
-#[derive(Clone)]
-struct DateService(Rc<DateServiceInner>);
-
-struct DateServiceInner {
-    current: Cell<Option<(Date, Instant)>>,
+/// Service for update Date and Instant periodically at 500 millis interval.
+struct DateService {
+    current: Rc<Cell<(Date, Instant)>>,
+    handle: JoinHandle<()>,
 }
 
-impl DateServiceInner {
-    fn new() -> Self {
-        DateServiceInner {
-            current: Cell::new(None),
-        }
-    }
-
-    fn reset(&self) {
-        self.current.take();
-    }
-
-    fn update(&self) {
-        let now = Instant::now();
-        let date = Date::new();
-        self.current.set(Some((date, now)));
+impl Drop for DateService {
+    fn drop(&mut self) {
+        // stop the timer update async task on drop.
+        self.handle.abort();
     }
 }
 
 impl DateService {
     fn new() -> Self {
-        DateService(Rc::new(DateServiceInner::new()))
-    }
+        // shared date and timer for DateService and update async task.
+        let current = Rc::new(Cell::new((Date::new(), Instant::now())));
+        let current_clone = Rc::clone(&current);
+        // spawn an async task sleep for 500 milli and update current date/timer in a loop.
+        // handle is used to stop the task on DateService drop.
+        let handle = actix_rt::spawn(async move {
+            #[cfg(test)]
+            let _notify = notify_on_drop::NotifyOnDrop::new();
 
-    fn check_date(&self) {
-        if self.0.current.get().is_none() {
-            self.0.update();
+            let mut interval = interval(Duration::from_millis(500));
+            loop {
+                let now = interval.tick().await;
+                let date = Date::new();
+                current_clone.set((date, now));
+            }
+        });
 
-            // periodic date update
-            let s = self.clone();
-            actix_rt::spawn(delay_for(Duration::from_millis(500)).then(move |_| {
-                s.0.reset();
-                future::ready(())
-            }));
-        }
+        DateService { current, handle }
     }
 
     fn now(&self) -> Instant {
-        self.check_date();
-        self.0.current.get().unwrap().1
+        self.current.get().1
     }
 
     fn set_date<F: FnMut(&Date)>(&self, mut f: F) {
-        self.check_date();
-        f(&self.0.current.get().unwrap().0);
+        f(&self.current.get().0);
+    }
+}
+
+// TODO: move to a util module for testing all spawn handle drop style tasks.
+#[cfg(test)]
+/// Test Module for checking the drop state of certain async tasks that are spawned
+/// with `actix_rt::spawn`
+///
+/// The target task must explicitly generate `NotifyOnDrop` when spawn the task
+mod notify_on_drop {
+    use std::cell::RefCell;
+
+    thread_local! {
+        static NOTIFY_DROPPED: RefCell<Option<bool>> = RefCell::new(None);
+    }
+
+    /// Check if the spawned task is dropped.
+    ///
+    /// # Panic:
+    ///
+    /// When there was no `NotifyOnDrop` instance on current thread
+    pub(crate) fn is_dropped() -> bool {
+        NOTIFY_DROPPED.with(|bool| {
+            bool.borrow()
+                .expect("No NotifyOnDrop existed on current thread")
+        })
+    }
+
+    pub(crate) struct NotifyOnDrop;
+
+    impl NotifyOnDrop {
+        /// # Panic:
+        ///
+        /// When construct multiple instances on any given thread.
+        pub(crate) fn new() -> Self {
+            NOTIFY_DROPPED.with(|bool| {
+                let mut bool = bool.borrow_mut();
+                if bool.is_some() {
+                    panic!("NotifyOnDrop existed on current thread");
+                } else {
+                    *bool = Some(false);
+                }
+            });
+
+            NotifyOnDrop
+        }
+    }
+
+    impl Drop for NotifyOnDrop {
+        fn drop(&mut self) {
+            NOTIFY_DROPPED.with(|bool| {
+                if let Some(b) = bool.borrow_mut().as_mut() {
+                    *b = true;
+                }
+            });
+        }
     }
 }
 
@@ -288,14 +336,53 @@ impl DateService {
 mod tests {
     use super::*;
 
-    // Test modifying the date from within the closure
-    // passed to `set_date`
-    #[test]
-    fn test_evil_date() {
-        let service = DateService::new();
-        // Make sure that `check_date` doesn't try to spawn a task
-        service.0.update();
-        service.set_date(|_| service.0.reset());
+    use actix_rt::task::yield_now;
+
+    #[actix_rt::test]
+    async fn test_date_service_update() {
+        let settings = ServiceConfig::new(KeepAlive::Os, 0, 0, false, None);
+
+        yield_now().await;
+
+        let mut buf1 = BytesMut::with_capacity(DATE_VALUE_LENGTH + 10);
+        settings.set_date(&mut buf1);
+        let now1 = settings.now();
+
+        sleep_until(Instant::now() + Duration::from_secs(2)).await;
+        yield_now().await;
+
+        let now2 = settings.now();
+        let mut buf2 = BytesMut::with_capacity(DATE_VALUE_LENGTH + 10);
+        settings.set_date(&mut buf2);
+
+        assert_ne!(now1, now2);
+
+        assert_ne!(buf1, buf2);
+
+        drop(settings);
+        assert!(notify_on_drop::is_dropped());
+    }
+
+    #[actix_rt::test]
+    async fn test_date_service_drop() {
+        let service = Rc::new(DateService::new());
+
+        // yield so date service have a chance to register the spawned timer update task.
+        yield_now().await;
+
+        let clone1 = service.clone();
+        let clone2 = service.clone();
+        let clone3 = service.clone();
+
+        drop(clone1);
+        assert_eq!(false, notify_on_drop::is_dropped());
+        drop(clone2);
+        assert_eq!(false, notify_on_drop::is_dropped());
+        drop(clone3);
+        assert_eq!(false, notify_on_drop::is_dropped());
+
+        drop(service);
+        assert!(notify_on_drop::is_dropped());
     }
 
     #[test]
diff --git a/actix-http/src/encoding/decoder.rs b/actix-http/src/encoding/decoder.rs
index b60435859..f0abae865 100644
--- a/actix-http/src/encoding/decoder.rs
+++ b/actix-http/src/encoding/decoder.rs
@@ -1,25 +1,31 @@
-use std::future::Future;
-use std::io::{self, Write};
-use std::pin::Pin;
-use std::task::{Context, Poll};
+//! Stream decoders.
 
-use actix_threadpool::{run, CpuFuture};
+use std::{
+    future::Future,
+    io::{self, Write as _},
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use actix_rt::task::{spawn_blocking, JoinHandle};
 use brotli2::write::BrotliDecoder;
 use bytes::Bytes;
 use flate2::write::{GzDecoder, ZlibDecoder};
 use futures_core::{ready, Stream};
 
-use super::Writer;
-use crate::error::PayloadError;
-use crate::http::header::{ContentEncoding, HeaderMap, CONTENT_ENCODING};
+use crate::{
+    encoding::Writer,
+    error::{BlockingError, PayloadError},
+    http::header::{ContentEncoding, HeaderMap, CONTENT_ENCODING},
+};
 
-const INPLACE: usize = 2049;
+const MAX_CHUNK_SIZE_DECODE_IN_PLACE: usize = 2049;
 
 pub struct Decoder<S> {
     decoder: Option<ContentDecoder>,
     stream: S,
     eof: bool,
-    fut: Option<CpuFuture<(Option<Bytes>, ContentDecoder), io::Error>>,
+    fut: Option<JoinHandle<Result<(Option<Bytes>, ContentDecoder), io::Error>>>,
 }
 
 impl<S> Decoder<S>
@@ -41,6 +47,7 @@ where
             ))),
             _ => None,
         };
+
         Decoder {
             decoder,
             stream,
@@ -53,15 +60,11 @@ where
     #[inline]
     pub fn from_headers(stream: S, headers: &HeaderMap) -> Decoder<S> {
         // check content-encoding
-        let encoding = if let Some(enc) = headers.get(&CONTENT_ENCODING) {
-            if let Ok(enc) = enc.to_str() {
-                ContentEncoding::from(enc)
-            } else {
-                ContentEncoding::Identity
-            }
-        } else {
-            ContentEncoding::Identity
-        };
+        let encoding = headers
+            .get(&CONTENT_ENCODING)
+            .and_then(|val| val.to_str().ok())
+            .map(ContentEncoding::from)
+            .unwrap_or(ContentEncoding::Identity);
 
         Self::new(stream, encoding)
     }
@@ -79,12 +82,12 @@ where
     ) -> Poll<Option<Self::Item>> {
         loop {
             if let Some(ref mut fut) = self.fut {
-                let (chunk, decoder) = match ready!(Pin::new(fut).poll(cx)) {
-                    Ok(item) => item,
-                    Err(e) => return Poll::Ready(Some(Err(e.into()))),
-                };
+                let (chunk, decoder) =
+                    ready!(Pin::new(fut).poll(cx)).map_err(|_| BlockingError)??;
+
                 self.decoder = Some(decoder);
                 self.fut.take();
+
                 if let Some(chunk) = chunk {
                     return Poll::Ready(Some(Ok(chunk)));
                 }
@@ -94,29 +97,34 @@ where
                 return Poll::Ready(None);
             }
 
-            match Pin::new(&mut self.stream).poll_next(cx) {
-                Poll::Ready(Some(Err(err))) => return Poll::Ready(Some(Err(err))),
-                Poll::Ready(Some(Ok(chunk))) => {
+            match ready!(Pin::new(&mut self.stream).poll_next(cx)) {
+                Some(Err(err)) => return Poll::Ready(Some(Err(err))),
+
+                Some(Ok(chunk)) => {
                     if let Some(mut decoder) = self.decoder.take() {
-                        if chunk.len() < INPLACE {
+                        if chunk.len() < MAX_CHUNK_SIZE_DECODE_IN_PLACE {
                             let chunk = decoder.feed_data(chunk)?;
                             self.decoder = Some(decoder);
+
                             if let Some(chunk) = chunk {
                                 return Poll::Ready(Some(Ok(chunk)));
                             }
                         } else {
-                            self.fut = Some(run(move || {
+                            self.fut = Some(spawn_blocking(move || {
                                 let chunk = decoder.feed_data(chunk)?;
                                 Ok((chunk, decoder))
                             }));
                         }
+
                         continue;
                     } else {
                         return Poll::Ready(Some(Ok(chunk)));
                     }
                 }
-                Poll::Ready(None) => {
+
+                None => {
                     self.eof = true;
+
                     return if let Some(mut decoder) = self.decoder.take() {
                         match decoder.feed_eof() {
                             Ok(Some(res)) => Poll::Ready(Some(Ok(res))),
@@ -127,10 +135,8 @@ where
                         Poll::Ready(None)
                     };
                 }
-                Poll::Pending => break,
             }
         }
-        Poll::Pending
     }
 }
 
@@ -146,6 +152,7 @@ impl ContentDecoder {
             ContentDecoder::Br(ref mut decoder) => match decoder.flush() {
                 Ok(()) => {
                     let b = decoder.get_mut().take();
+
                     if !b.is_empty() {
                         Ok(Some(b))
                     } else {
@@ -154,9 +161,11 @@ impl ContentDecoder {
                 }
                 Err(e) => Err(e),
             },
+
             ContentDecoder::Gzip(ref mut decoder) => match decoder.try_finish() {
                 Ok(_) => {
                     let b = decoder.get_mut().take();
+
                     if !b.is_empty() {
                         Ok(Some(b))
                     } else {
@@ -165,6 +174,7 @@ impl ContentDecoder {
                 }
                 Err(e) => Err(e),
             },
+
             ContentDecoder::Deflate(ref mut decoder) => match decoder.try_finish() {
                 Ok(_) => {
                     let b = decoder.get_mut().take();
@@ -185,6 +195,7 @@ impl ContentDecoder {
                 Ok(_) => {
                     decoder.flush()?;
                     let b = decoder.get_mut().take();
+
                     if !b.is_empty() {
                         Ok(Some(b))
                     } else {
@@ -193,10 +204,12 @@ impl ContentDecoder {
                 }
                 Err(e) => Err(e),
             },
+
             ContentDecoder::Gzip(ref mut decoder) => match decoder.write_all(&data) {
                 Ok(_) => {
                     decoder.flush()?;
                     let b = decoder.get_mut().take();
+
                     if !b.is_empty() {
                         Ok(Some(b))
                     } else {
@@ -205,9 +218,11 @@ impl ContentDecoder {
                 }
                 Err(e) => Err(e),
             },
+
             ContentDecoder::Deflate(ref mut decoder) => match decoder.write_all(&data) {
                 Ok(_) => {
                     decoder.flush()?;
+
                     let b = decoder.get_mut().take();
                     if !b.is_empty() {
                         Ok(Some(b))
diff --git a/actix-http/src/encoding/encoder.rs b/actix-http/src/encoding/encoder.rs
index eb1821285..ee0587fbd 100644
--- a/actix-http/src/encoding/encoder.rs
+++ b/actix-http/src/encoding/encoder.rs
@@ -1,24 +1,32 @@
-//! Stream encoder
-use std::future::Future;
-use std::io::{self, Write};
-use std::pin::Pin;
-use std::task::{Context, Poll};
+//! Stream encoders.
 
-use actix_threadpool::{run, CpuFuture};
+use std::{
+    future::Future,
+    io::{self, Write as _},
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use actix_rt::task::{spawn_blocking, JoinHandle};
 use brotli2::write::BrotliEncoder;
 use bytes::Bytes;
 use flate2::write::{GzEncoder, ZlibEncoder};
 use futures_core::ready;
 use pin_project::pin_project;
 
-use crate::body::{Body, BodySize, MessageBody, ResponseBody};
-use crate::http::header::{ContentEncoding, CONTENT_ENCODING};
-use crate::http::{HeaderValue, StatusCode};
-use crate::{Error, ResponseHead};
+use crate::{
+    body::{Body, BodySize, MessageBody, ResponseBody},
+    http::{
+        header::{ContentEncoding, CONTENT_ENCODING},
+        HeaderValue, StatusCode,
+    },
+    Error, ResponseHead,
+};
 
 use super::Writer;
+use crate::error::BlockingError;
 
-const INPLACE: usize = 1024;
+const MAX_CHUNK_SIZE_ENCODE_IN_PLACE: usize = 1024;
 
 #[pin_project]
 pub struct Encoder<B> {
@@ -26,7 +34,7 @@ pub struct Encoder<B> {
     #[pin]
     body: EncoderBody<B>,
     encoder: Option<ContentEncoder>,
-    fut: Option<CpuFuture<ContentEncoder, io::Error>>,
+    fut: Option<JoinHandle<Result<ContentEncoder, io::Error>>>,
 }
 
 impl<B: MessageBody> Encoder<B> {
@@ -70,6 +78,7 @@ impl<B: MessageBody> Encoder<B> {
                 });
             }
         }
+
         ResponseBody::Body(Encoder {
             body,
             eof: false,
@@ -135,32 +144,35 @@ impl<B: MessageBody> MessageBody for Encoder<B> {
             }
 
             if let Some(ref mut fut) = this.fut {
-                let mut encoder = match ready!(Pin::new(fut).poll(cx)) {
-                    Ok(item) => item,
-                    Err(e) => return Poll::Ready(Some(Err(e.into()))),
-                };
+                let mut encoder =
+                    ready!(Pin::new(fut).poll(cx)).map_err(|_| BlockingError)??;
+
                 let chunk = encoder.take();
                 *this.encoder = Some(encoder);
                 this.fut.take();
+
                 if !chunk.is_empty() {
                     return Poll::Ready(Some(Ok(chunk)));
                 }
             }
 
-            let result = this.body.as_mut().poll_next(cx);
+            let result = ready!(this.body.as_mut().poll_next(cx));
 
             match result {
-                Poll::Ready(Some(Ok(chunk))) => {
+                Some(Err(err)) => return Poll::Ready(Some(Err(err))),
+
+                Some(Ok(chunk)) => {
                     if let Some(mut encoder) = this.encoder.take() {
-                        if chunk.len() < INPLACE {
+                        if chunk.len() < MAX_CHUNK_SIZE_ENCODE_IN_PLACE {
                             encoder.write(&chunk)?;
                             let chunk = encoder.take();
                             *this.encoder = Some(encoder);
+
                             if !chunk.is_empty() {
                                 return Poll::Ready(Some(Ok(chunk)));
                             }
                         } else {
-                            *this.fut = Some(run(move || {
+                            *this.fut = Some(spawn_blocking(move || {
                                 encoder.write(&chunk)?;
                                 Ok(encoder)
                             }));
@@ -169,7 +181,8 @@ impl<B: MessageBody> MessageBody for Encoder<B> {
                         return Poll::Ready(Some(Ok(chunk)));
                     }
                 }
-                Poll::Ready(None) => {
+
+                None => {
                     if let Some(encoder) = this.encoder.take() {
                         let chunk = encoder.finish()?;
                         if chunk.is_empty() {
@@ -182,7 +195,6 @@ impl<B: MessageBody> MessageBody for Encoder<B> {
                         return Poll::Ready(None);
                     }
                 }
-                val => return val,
             }
         }
     }
diff --git a/actix-http/src/encoding/mod.rs b/actix-http/src/encoding/mod.rs
index 9eaf4104e..cb271c638 100644
--- a/actix-http/src/encoding/mod.rs
+++ b/actix-http/src/encoding/mod.rs
@@ -1,4 +1,5 @@
-//! Content-Encoding support
+//! Content-Encoding support.
+
 use std::io;
 
 use bytes::{Bytes, BytesMut};
diff --git a/actix-http/src/error.rs b/actix-http/src/error.rs
index e93c077af..97f2b3eff 100644
--- a/actix-http/src/error.rs
+++ b/actix-http/src/error.rs
@@ -7,25 +7,24 @@ use std::string::FromUtf8Error;
 use std::{fmt, io, result};
 
 use actix_codec::{Decoder, Encoder};
-pub use actix_threadpool::BlockingError;
 use actix_utils::dispatcher::DispatcherError as FramedDispatcherError;
 use actix_utils::timeout::TimeoutError;
 use bytes::BytesMut;
 use derive_more::{Display, From};
-pub use futures_channel::oneshot::Canceled;
 use http::uri::InvalidUri;
 use http::{header, Error as HttpError, StatusCode};
 use serde::de::value::Error as DeError;
 use serde_json::error::Error as JsonError;
 use serde_urlencoded::ser::Error as FormError;
 
-// re-export for convenience
 use crate::body::Body;
-pub use crate::cookie::ParseError as CookieParseError;
 use crate::helpers::Writer;
 use crate::response::{Response, ResponseBuilder};
 
-/// A specialized [`Result`](https://doc.rust-lang.org/std/result/enum.Result.html)
+#[cfg(feature = "cookies")]
+pub use crate::cookie::ParseError as CookieParseError;
+
+/// A specialized [`std::result::Result`]
 /// for actix web operations
 ///
 /// This typedef is generally used to avoid writing out
@@ -40,7 +39,7 @@ pub type Result<T, E = Error> = result::Result<T, E>;
 /// converting errors with `into()`.
 ///
 /// Whenever it is created from an external object a response error is created
-/// for it that can be used to create an http response from it this means that
+/// for it that can be used to create an HTTP response from it this means that
 /// if you have access to an actix `Error` you can always get a
 /// `ResponseError` reference from it.
 pub struct Error {
@@ -100,10 +99,6 @@ impl fmt::Debug for Error {
 }
 
 impl std::error::Error for Error {
-    fn cause(&self) -> Option<&dyn std::error::Error> {
-        None
-    }
-
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
         None
     }
@@ -153,7 +148,10 @@ impl From<ResponseBuilder> for Error {
     }
 }
 
-/// Return `GATEWAY_TIMEOUT` for `TimeoutError`
+/// Inspects the underlying enum and returns an appropriate status code.
+///
+/// If the variant is [`TimeoutError::Service`], the error code of the service is returned.
+/// Otherwise, [`StatusCode::GATEWAY_TIMEOUT`] is returned.
 impl<E: ResponseError> ResponseError for TimeoutError<E> {
     fn status_code(&self) -> StatusCode {
         match self {
@@ -167,48 +165,41 @@ impl<E: ResponseError> ResponseError for TimeoutError<E> {
 #[display(fmt = "UnknownError")]
 struct UnitError;
 
-/// `InternalServerError` for `UnitError`
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`UnitError`].
 impl ResponseError for UnitError {}
 
-/// `InternalServerError` for `JsonError`
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`JsonError`].
 impl ResponseError for JsonError {}
 
-/// `InternalServerError` for `FormError`
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`FormError`].
 impl ResponseError for FormError {}
 
 #[cfg(feature = "openssl")]
-/// `InternalServerError` for `openssl::ssl::Error`
-impl ResponseError for actix_connect::ssl::openssl::SslError {}
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`actix_tls::accept::openssl::SslError`].
+impl ResponseError for actix_tls::accept::openssl::SslError {}
 
-#[cfg(feature = "openssl")]
-/// `InternalServerError` for `openssl::ssl::HandshakeError`
-impl<T: std::fmt::Debug> ResponseError for actix_tls::openssl::HandshakeError<T> {}
-
-/// Return `BAD_REQUEST` for `de::value::Error`
+/// Returns [`StatusCode::BAD_REQUEST`] for [`DeError`].
 impl ResponseError for DeError {
     fn status_code(&self) -> StatusCode {
         StatusCode::BAD_REQUEST
     }
 }
 
-/// `InternalServerError` for `Canceled`
-impl ResponseError for Canceled {}
-
-/// `InternalServerError` for `BlockingError`
-impl<E: fmt::Debug> ResponseError for BlockingError<E> {}
-
-/// Return `BAD_REQUEST` for `Utf8Error`
+/// Returns [`StatusCode::BAD_REQUEST`] for [`Utf8Error`].
 impl ResponseError for Utf8Error {
     fn status_code(&self) -> StatusCode {
         StatusCode::BAD_REQUEST
     }
 }
 
-/// Return `InternalServerError` for `HttpError`,
-/// Response generation can return `HttpError`, so it is internal error
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`HttpError`].
 impl ResponseError for HttpError {}
 
-/// Return `InternalServerError` for `io::Error`
+/// Inspects the underlying [`io::ErrorKind`] and returns an appropriate status code.
+///
+/// If the error is [`io::ErrorKind::NotFound`], [`StatusCode::NOT_FOUND`] is returned. If the
+/// error is [`io::ErrorKind::PermissionDenied`], [`StatusCode::FORBIDDEN`] is returned. Otherwise,
+/// [`StatusCode::INTERNAL_SERVER_ERROR`] is returned.
 impl ResponseError for io::Error {
     fn status_code(&self) -> StatusCode {
         match self.kind() {
@@ -219,7 +210,7 @@ impl ResponseError for io::Error {
     }
 }
 
-/// `BadRequest` for `InvalidHeaderValue`
+/// Returns [`StatusCode::BAD_REQUEST`] for [`header::InvalidHeaderValue`].
 impl ResponseError for header::InvalidHeaderValue {
     fn status_code(&self) -> StatusCode {
         StatusCode::BAD_REQUEST
@@ -308,33 +299,60 @@ impl From<httparse::Error> for ParseError {
     }
 }
 
+/// A set of errors that can occur running blocking tasks in thread pool.
+#[derive(Debug, Display)]
+#[display(fmt = "Blocking thread pool is gone")]
+pub struct BlockingError;
+
+impl std::error::Error for BlockingError {}
+
+/// `InternalServerError` for `BlockingError`
+impl ResponseError for BlockingError {}
+
 #[derive(Display, Debug)]
 /// A set of errors that can occur during payload parsing
 pub enum PayloadError {
     /// A payload reached EOF, but is not complete.
     #[display(
-        fmt = "A payload reached EOF, but is not complete. With error: {:?}",
+        fmt = "A payload reached EOF, but is not complete. Inner error: {:?}",
         _0
     )]
     Incomplete(Option<io::Error>),
-    /// Content encoding stream corruption
+
+    /// Content encoding stream corruption.
     #[display(fmt = "Can not decode content-encoding.")]
     EncodingCorrupted,
-    /// A payload reached size limit.
-    #[display(fmt = "A payload reached size limit.")]
+
+    /// Payload reached size limit.
+    #[display(fmt = "Payload reached size limit.")]
     Overflow,
-    /// A payload length is unknown.
-    #[display(fmt = "A payload length is unknown.")]
+
+    /// Payload length is unknown.
+    #[display(fmt = "Payload length is unknown.")]
     UnknownLength,
-    /// Http2 payload error
+
+    /// HTTP/2 payload error.
     #[display(fmt = "{}", _0)]
     Http2Payload(h2::Error),
-    /// Io error
+
+    /// Generic I/O error.
     #[display(fmt = "{}", _0)]
     Io(io::Error),
 }
 
-impl std::error::Error for PayloadError {}
+impl std::error::Error for PayloadError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            PayloadError::Incomplete(None) => None,
+            PayloadError::Incomplete(Some(err)) => Some(err as &dyn std::error::Error),
+            PayloadError::EncodingCorrupted => None,
+            PayloadError::Overflow => None,
+            PayloadError::UnknownLength => None,
+            PayloadError::Http2Payload(err) => Some(err as &dyn std::error::Error),
+            PayloadError::Io(err) => Some(err as &dyn std::error::Error),
+        }
+    }
+}
 
 impl From<h2::Error> for PayloadError {
     fn from(err: h2::Error) -> Self {
@@ -354,15 +372,12 @@ impl From<io::Error> for PayloadError {
     }
 }
 
-impl From<BlockingError<io::Error>> for PayloadError {
-    fn from(err: BlockingError<io::Error>) -> Self {
-        match err {
-            BlockingError::Error(e) => PayloadError::Io(e),
-            BlockingError::Canceled => PayloadError::Io(io::Error::new(
-                io::ErrorKind::Other,
-                "Operation is canceled",
-            )),
-        }
+impl From<BlockingError> for PayloadError {
+    fn from(_: BlockingError) -> Self {
+        PayloadError::Io(io::Error::new(
+            io::ErrorKind::Other,
+            "Operation is canceled",
+        ))
     }
 }
 
@@ -380,6 +395,7 @@ impl ResponseError for PayloadError {
 }
 
 /// Return `BadRequest` for `cookie::ParseError`
+#[cfg(feature = "cookies")]
 impl ResponseError for crate::cookie::ParseError {
     fn status_code(&self) -> StatusCode {
         StatusCode::BAD_REQUEST
@@ -387,7 +403,7 @@ impl ResponseError for crate::cookie::ParseError {
 }
 
 #[derive(Debug, Display, From)]
-/// A set of errors that can occur during dispatching http requests
+/// A set of errors that can occur during dispatching HTTP requests
 pub enum DispatchError {
     /// Service error
     Service(Error),
@@ -951,16 +967,6 @@ where
     InternalError::new(err, StatusCode::NETWORK_AUTHENTICATION_REQUIRED).into()
 }
 
-#[cfg(feature = "actors")]
-/// `InternalServerError` for `actix::MailboxError`
-/// This is supported on feature=`actors` only
-impl ResponseError for actix::MailboxError {}
-
-#[cfg(feature = "actors")]
-/// `InternalServerError` for `actix::ResolverError`
-/// This is supported on feature=`actors` only
-impl ResponseError for actix::actors::resolver::ResolverError {}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -1018,22 +1024,22 @@ mod tests {
     fn test_payload_error() {
         let err: PayloadError =
             io::Error::new(io::ErrorKind::Other, "ParseError").into();
-        assert!(format!("{}", err).contains("ParseError"));
+        assert!(err.to_string().contains("ParseError"));
 
         let err = PayloadError::Incomplete(None);
         assert_eq!(
-            format!("{}", err),
-            "A payload reached EOF, but is not complete. With error: None"
+            err.to_string(),
+            "A payload reached EOF, but is not complete. Inner error: None"
         );
     }
 
     macro_rules! from {
         ($from:expr => $error:pat) => {
             match ParseError::from($from) {
-                e @ $error => {
-                    assert!(format!("{}", e).len() >= 5);
+                err @ $error => {
+                    assert!(err.to_string().len() >= 5);
                 }
-                e => unreachable!("{:?}", e),
+                err => unreachable!("{:?}", err),
             }
         };
     }
@@ -1076,7 +1082,7 @@ mod tests {
         let err = PayloadError::Overflow;
         let resp_err: &dyn ResponseError = &err;
         let err = resp_err.downcast_ref::<PayloadError>().unwrap();
-        assert_eq!(err.to_string(), "A payload reached size limit.");
+        assert_eq!(err.to_string(), "Payload reached size limit.");
         let not_err = resp_err.downcast_ref::<ContentTypeError>();
         assert!(not_err.is_none());
     }
diff --git a/actix-http/src/extensions.rs b/actix-http/src/extensions.rs
index 96e01767b..5fdcefd6d 100644
--- a/actix-http/src/extensions.rs
+++ b/actix-http/src/extensions.rs
@@ -1,66 +1,133 @@
-use std::any::{Any, TypeId};
-use std::fmt;
+use std::{
+    any::{Any, TypeId},
+    fmt, mem,
+};
 
-use fxhash::FxHashMap;
+use ahash::AHashMap;
 
+/// A type map for request extensions.
+///
+/// All entries into this map must be owned types (or static references).
 #[derive(Default)]
-/// A type map of request extensions.
 pub struct Extensions {
     /// Use FxHasher with a std HashMap with for faster
     /// lookups on the small `TypeId` (u64 equivalent) keys.
-    map: FxHashMap<TypeId, Box<dyn Any>>,
+    map: AHashMap<TypeId, Box<dyn Any>>,
 }
 
 impl Extensions {
-    /// Create an empty `Extensions`.
+    /// Creates an empty `Extensions`.
     #[inline]
     pub fn new() -> Extensions {
         Extensions {
-            map: FxHashMap::default(),
+            map: AHashMap::default(),
         }
     }
 
-    /// Insert a type into this `Extensions`.
+    /// Insert an item into the map.
     ///
-    /// If a extension of this type already existed, it will
-    /// be returned.
-    pub fn insert<T: 'static>(&mut self, val: T) {
-        self.map.insert(TypeId::of::<T>(), Box::new(val));
+    /// If an item of this type was already stored, it will be replaced and returned.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    /// assert_eq!(map.insert(""), None);
+    /// assert_eq!(map.insert(1u32), None);
+    /// assert_eq!(map.insert(2u32), Some(1u32));
+    /// assert_eq!(*map.get::<u32>().unwrap(), 2u32);
+    /// ```
+    pub fn insert<T: 'static>(&mut self, val: T) -> Option<T> {
+        self.map
+            .insert(TypeId::of::<T>(), Box::new(val))
+            .and_then(downcast_owned)
     }
 
-    /// Check if container contains entry
+    /// Check if map contains an item of a given type.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    /// assert!(!map.contains::<u32>());
+    ///
+    /// assert_eq!(map.insert(1u32), None);
+    /// assert!(map.contains::<u32>());
+    /// ```
     pub fn contains<T: 'static>(&self) -> bool {
         self.map.contains_key(&TypeId::of::<T>())
     }
 
-    /// Get a reference to a type previously inserted on this `Extensions`.
+    /// Get a reference to an item of a given type.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    /// map.insert(1u32);
+    /// assert_eq!(map.get::<u32>(), Some(&1u32));
+    /// ```
     pub fn get<T: 'static>(&self) -> Option<&T> {
         self.map
             .get(&TypeId::of::<T>())
             .and_then(|boxed| boxed.downcast_ref())
     }
 
-    /// Get a mutable reference to a type previously inserted on this `Extensions`.
+    /// Get a mutable reference to an item of a given type.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    /// map.insert(1u32);
+    /// assert_eq!(map.get_mut::<u32>(), Some(&mut 1u32));
+    /// ```
     pub fn get_mut<T: 'static>(&mut self) -> Option<&mut T> {
         self.map
             .get_mut(&TypeId::of::<T>())
             .and_then(|boxed| boxed.downcast_mut())
     }
 
-    /// Remove a type from this `Extensions`.
+    /// Remove an item from the map of a given type.
     ///
-    /// If a extension of this type existed, it will be returned.
+    /// If an item of this type was already stored, it will be returned.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    ///
+    /// map.insert(1u32);
+    /// assert_eq!(map.get::<u32>(), Some(&1u32));
+    ///
+    /// assert_eq!(map.remove::<u32>(), Some(1u32));
+    /// assert!(!map.contains::<u32>());
+    /// ```
     pub fn remove<T: 'static>(&mut self) -> Option<T> {
-        self.map
-            .remove(&TypeId::of::<T>())
-            .and_then(|boxed| boxed.downcast().ok().map(|boxed| *boxed))
+        self.map.remove(&TypeId::of::<T>()).and_then(downcast_owned)
     }
 
     /// Clear the `Extensions` of all inserted extensions.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    ///
+    /// map.insert(1u32);
+    /// assert!(map.contains::<u32>());
+    ///
+    /// map.clear();
+    /// assert!(!map.contains::<u32>());
+    /// ```
     #[inline]
     pub fn clear(&mut self) {
         self.map.clear();
     }
+
+    /// Extends self with the items from another `Extensions`.
+    pub fn extend(&mut self, other: Extensions) {
+        self.map.extend(other.map);
+    }
+
+    /// Sets (or overrides) items from `other` into this map.
+    pub(crate) fn drain_from(&mut self, other: &mut Self) {
+        self.map.extend(mem::take(&mut other.map));
+    }
 }
 
 impl fmt::Debug for Extensions {
@@ -69,6 +136,10 @@ impl fmt::Debug for Extensions {
     }
 }
 
+fn downcast_owned<T: 'static>(boxed: Box<dyn Any>) -> Option<T> {
+    boxed.downcast().ok().map(|boxed| *boxed)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -178,4 +249,57 @@ mod tests {
         assert_eq!(extensions.get::<bool>(), None);
         assert_eq!(extensions.get(), Some(&MyType(10)));
     }
+
+    #[test]
+    fn test_extend() {
+        #[derive(Debug, PartialEq)]
+        struct MyType(i32);
+
+        let mut extensions = Extensions::new();
+
+        extensions.insert(5i32);
+        extensions.insert(MyType(10));
+
+        let mut other = Extensions::new();
+
+        other.insert(15i32);
+        other.insert(20u8);
+
+        extensions.extend(other);
+
+        assert_eq!(extensions.get(), Some(&15i32));
+        assert_eq!(extensions.get_mut(), Some(&mut 15i32));
+
+        assert_eq!(extensions.remove::<i32>(), Some(15i32));
+        assert!(extensions.get::<i32>().is_none());
+
+        assert_eq!(extensions.get::<bool>(), None);
+        assert_eq!(extensions.get(), Some(&MyType(10)));
+
+        assert_eq!(extensions.get(), Some(&20u8));
+        assert_eq!(extensions.get_mut(), Some(&mut 20u8));
+    }
+
+    #[test]
+    fn test_drain_from() {
+        let mut ext = Extensions::new();
+        ext.insert(2isize);
+
+        let mut more_ext = Extensions::new();
+
+        more_ext.insert(5isize);
+        more_ext.insert(5usize);
+
+        assert_eq!(ext.get::<isize>(), Some(&2isize));
+        assert_eq!(ext.get::<usize>(), None);
+        assert_eq!(more_ext.get::<isize>(), Some(&5isize));
+        assert_eq!(more_ext.get::<usize>(), Some(&5usize));
+
+        ext.drain_from(&mut more_ext);
+
+        assert_eq!(ext.get::<isize>(), Some(&5isize));
+        assert_eq!(ext.get::<usize>(), Some(&5usize));
+        assert_eq!(more_ext.get::<isize>(), None);
+        assert_eq!(more_ext.get::<usize>(), None);
+    }
 }
diff --git a/actix-http/src/h1/client.rs b/actix-http/src/h1/client.rs
index 2e0103409..4a6104688 100644
--- a/actix-http/src/h1/client.rs
+++ b/actix-http/src/h1/client.rs
@@ -223,15 +223,3 @@ impl Encoder<Message<(RequestHeadType, BodySize)>> for ClientCodec {
         Ok(())
     }
 }
-
-pub struct Writer<'a>(pub &'a mut BytesMut);
-
-impl<'a> io::Write for Writer<'a> {
-    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        self.0.extend_from_slice(buf);
-        Ok(buf.len())
-    }
-    fn flush(&mut self) -> io::Result<()> {
-        Ok(())
-    }
-}
diff --git a/actix-http/src/h1/codec.rs b/actix-http/src/h1/codec.rs
index 036f16670..634ca25e8 100644
--- a/actix-http/src/h1/codec.rs
+++ b/actix-http/src/h1/codec.rs
@@ -58,6 +58,7 @@ impl Codec {
         } else {
             Flags::empty()
         };
+
         Codec {
             config,
             flags,
@@ -69,26 +70,26 @@ impl Codec {
         }
     }
 
+    /// Check if request is upgrade.
     #[inline]
-    /// Check if request is upgrade
     pub fn upgrade(&self) -> bool {
         self.ctype == ConnectionType::Upgrade
     }
 
+    /// Check if last response is keep-alive.
     #[inline]
-    /// Check if last response is keep-alive
     pub fn keepalive(&self) -> bool {
         self.ctype == ConnectionType::KeepAlive
     }
 
+    /// Check if keep-alive enabled on server level.
     #[inline]
-    /// Check if keep-alive enabled on server level
     pub fn keepalive_enabled(&self) -> bool {
         self.flags.contains(Flags::KEEPALIVE_ENABLED)
     }
 
+    /// Check last request's message type.
     #[inline]
-    /// Check last request's message type
     pub fn message_type(&self) -> MessageType {
         if self.flags.contains(Flags::STREAM) {
             MessageType::Stream
@@ -110,8 +111,8 @@ impl Decoder for Codec {
     type Error = ParseError;
 
     fn decode(&mut self, src: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
-        if self.payload.is_some() {
-            Ok(match self.payload.as_mut().unwrap().decode(src)? {
+        if let Some(ref mut payload) = self.payload {
+            Ok(match payload.decode(src)? {
                 Some(PayloadItem::Chunk(chunk)) => Some(Message::Chunk(Some(chunk))),
                 Some(PayloadItem::Eof) => {
                     self.payload.take();
@@ -198,10 +199,10 @@ mod tests {
     use http::Method;
 
     use super::*;
-    use crate::httpmessage::HttpMessage;
+    use crate::HttpMessage;
 
-    #[test]
-    fn test_http_request_chunked_payload_and_next_message() {
+    #[actix_rt::test]
+    async fn test_http_request_chunked_payload_and_next_message() {
         let mut codec = Codec::default();
 
         let mut buf = BytesMut::from(
diff --git a/actix-http/src/h1/decoder.rs b/actix-http/src/h1/decoder.rs
index 8e891dc5c..93a4b13d2 100644
--- a/actix-http/src/h1/decoder.rs
+++ b/actix-http/src/h1/decoder.rs
@@ -14,7 +14,7 @@ use crate::header::HeaderMap;
 use crate::message::{ConnectionType, ResponseHead};
 use crate::request::Request;
 
-const MAX_BUFFER_SIZE: usize = 131_072;
+pub(crate) const MAX_BUFFER_SIZE: usize = 131_072;
 const MAX_HEADERS: usize = 96;
 
 /// Incoming message decoder
@@ -137,7 +137,7 @@ pub(crate) trait MessageType: Sized {
                             expect = true;
                         }
                     }
-                    _ => (),
+                    _ => {}
                 }
 
                 headers.append(name, value);
@@ -203,7 +203,15 @@ impl MessageType for Request {
 
                     (len, method, uri, version, req.headers.len())
                 }
-                httparse::Status::Partial => return Ok(None),
+                httparse::Status::Partial => {
+                    return if src.len() >= MAX_BUFFER_SIZE {
+                        trace!("MAX_BUFFER_SIZE unprocessed data reached, closing");
+                        Err(ParseError::TooLarge)
+                    } else {
+                        // Return None to notify more read are needed for parsing request
+                        Ok(None)
+                    };
+                }
             }
         };
 
@@ -216,15 +224,12 @@ impl MessageType for Request {
         let decoder = match length {
             PayloadLength::Payload(pl) => pl,
             PayloadLength::UpgradeWebSocket => {
-                // upgrade(websocket)
+                // upgrade (WebSocket)
                 PayloadType::Stream(PayloadDecoder::eof())
             }
             PayloadLength::None => {
                 if method == Method::CONNECT {
                     PayloadType::Stream(PayloadDecoder::eof())
-                } else if src.len() >= MAX_BUFFER_SIZE {
-                    trace!("MAX_BUFFER_SIZE unprocessed data reached, closing");
-                    return Err(ParseError::TooLarge);
                 } else {
                     PayloadType::None
                 }
@@ -273,7 +278,14 @@ impl MessageType for ResponseHead {
 
                     (len, version, status, res.headers.len())
                 }
-                httparse::Status::Partial => return Ok(None),
+                httparse::Status::Partial => {
+                    return if src.len() >= MAX_BUFFER_SIZE {
+                        error!("MAX_BUFFER_SIZE unprocessed data reached, closing");
+                        Err(ParseError::TooLarge)
+                    } else {
+                        Ok(None)
+                    }
+                }
             }
         };
 
@@ -289,9 +301,6 @@ impl MessageType for ResponseHead {
         } else if status == StatusCode::SWITCHING_PROTOCOLS {
             // switching protocol or connect
             PayloadType::Stream(PayloadDecoder::eof())
-        } else if src.len() >= MAX_BUFFER_SIZE {
-            error!("MAX_BUFFER_SIZE unprocessed data reached, closing");
-            return Err(ParseError::TooLarge);
         } else {
             // for HTTP/1.0 read to eof and close connection
             if msg.version == Version::HTTP_10 {
@@ -643,7 +652,7 @@ mod tests {
     use super::*;
     use crate::error::ParseError;
     use crate::http::header::{HeaderName, SET_COOKIE};
-    use crate::httpmessage::HttpMessage;
+    use crate::HttpMessage;
 
     impl PayloadType {
         fn unwrap(self) -> PayloadDecoder {
@@ -685,7 +694,7 @@ mod tests {
             match MessageDecoder::<Request>::default().decode($e) {
                 Err(err) => match err {
                     ParseError::Io(_) => unreachable!("Parse error expected"),
-                    _ => (),
+                    _ => {}
                 },
                 _ => unreachable!("Error expected"),
             }
@@ -821,8 +830,8 @@ mod tests {
             .get_all(SET_COOKIE)
             .map(|v| v.to_str().unwrap().to_owned())
             .collect();
-        assert_eq!(val[1], "c1=cookie1");
-        assert_eq!(val[0], "c2=cookie2");
+        assert_eq!(val[0], "c1=cookie1");
+        assert_eq!(val[1], "c2=cookie2");
     }
 
     #[test]
diff --git a/actix-http/src/h1/dispatcher.rs b/actix-http/src/h1/dispatcher.rs
index 7c4de9707..6df579c0a 100644
--- a/actix-http/src/h1/dispatcher.rs
+++ b/actix-http/src/h1/dispatcher.rs
@@ -1,93 +1,96 @@
-use std::collections::VecDeque;
-use std::future::Future;
-use std::pin::Pin;
-use std::task::{Context, Poll};
-use std::{fmt, io, net};
+use std::{
+    collections::VecDeque,
+    fmt,
+    future::Future,
+    io, mem, net,
+    pin::Pin,
+    rc::Rc,
+    task::{Context, Poll},
+};
 
 use actix_codec::{AsyncRead, AsyncWrite, Decoder, Encoder, Framed, FramedParts};
-use actix_rt::time::{delay_until, Delay, Instant};
+use actix_rt::time::{sleep_until, Instant, Sleep};
 use actix_service::Service;
 use bitflags::bitflags;
 use bytes::{Buf, BytesMut};
+use futures_core::ready;
 use log::{error, trace};
 use pin_project::pin_project;
 
 use crate::body::{Body, BodySize, MessageBody, ResponseBody};
-use crate::cloneable::CloneableService;
 use crate::config::ServiceConfig;
 use crate::error::{DispatchError, Error};
 use crate::error::{ParseError, PayloadError};
-use crate::helpers::DataFactory;
-use crate::httpmessage::HttpMessage;
 use crate::request::Request;
 use crate::response::Response;
+use crate::service::HttpFlow;
+use crate::OnConnectData;
 
 use super::codec::Codec;
 use super::payload::{Payload, PayloadSender, PayloadStatus};
 use super::{Message, MessageType};
 
-const LW_BUFFER_SIZE: usize = 4096;
-const HW_BUFFER_SIZE: usize = 32_768;
+const LW_BUFFER_SIZE: usize = 1024;
+const HW_BUFFER_SIZE: usize = 1024 * 8;
 const MAX_PIPELINED_MESSAGES: usize = 16;
 
 bitflags! {
     pub struct Flags: u8 {
         const STARTED            = 0b0000_0001;
         const KEEPALIVE          = 0b0000_0010;
-        const POLLED             = 0b0000_0100;
-        const SHUTDOWN           = 0b0000_1000;
-        const READ_DISCONNECT    = 0b0001_0000;
-        const WRITE_DISCONNECT   = 0b0010_0000;
-        const UPGRADE            = 0b0100_0000;
+        const SHUTDOWN           = 0b0000_0100;
+        const READ_DISCONNECT    = 0b0000_1000;
+        const WRITE_DISCONNECT   = 0b0001_0000;
     }
 }
 
-#[pin_project::pin_project]
+#[pin_project]
 /// Dispatcher for HTTP/1.1 protocol
 pub struct Dispatcher<T, S, B, X, U>
 where
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error>,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
     #[pin]
     inner: DispatcherState<T, S, B, X, U>,
+
+    #[cfg(test)]
+    poll_count: u64,
 }
 
 #[pin_project(project = DispatcherStateProj)]
 enum DispatcherState<T, S, B, X, U>
 where
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error>,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
     Normal(#[pin] InnerDispatcher<T, S, B, X, U>),
-    Upgrade(Pin<Box<U::Future>>),
+    Upgrade(#[pin] U::Future),
 }
 
 #[pin_project(project = InnerDispatcherProj)]
 struct InnerDispatcher<T, S, B, X, U>
 where
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error>,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
-    service: CloneableService<S>,
-    expect: CloneableService<X>,
-    upgrade: Option<CloneableService<U>>,
-    on_connect: Option<Box<dyn DataFactory>>,
+    flow: Rc<HttpFlow<S, X, U>>,
+    on_connect_data: OnConnectData,
     flags: Flags,
     peer_addr: Option<net::SocketAddr>,
     error: Option<DispatchError>,
@@ -98,7 +101,8 @@ where
     messages: VecDeque<DispatcherMessage>,
 
     ka_expire: Instant,
-    ka_timer: Option<Delay>,
+    #[pin]
+    ka_timer: Option<Sleep>,
 
     io: Option<T>,
     read_buf: BytesMut,
@@ -115,130 +119,85 @@ enum DispatcherMessage {
 #[pin_project(project = StateProj)]
 enum State<S, B, X>
 where
-    S: Service<Request = Request>,
-    X: Service<Request = Request, Response = Request>,
+    S: Service<Request>,
+    X: Service<Request, Response = Request>,
     B: MessageBody,
 {
     None,
-    ExpectCall(Pin<Box<X::Future>>),
-    ServiceCall(Pin<Box<S::Future>>),
+    ExpectCall(#[pin] X::Future),
+    ServiceCall(#[pin] S::Future),
     SendPayload(#[pin] ResponseBody<B>),
 }
 
 impl<S, B, X> State<S, B, X>
 where
-    S: Service<Request = Request>,
-    X: Service<Request = Request, Response = Request>,
+    S: Service<Request>,
+    X: Service<Request, Response = Request>,
     B: MessageBody,
 {
     fn is_empty(&self) -> bool {
         matches!(self, State::None)
     }
-
-    fn is_call(&self) -> bool {
-        matches!(self, State::ServiceCall(_))
-    }
 }
+
 enum PollResponse {
     Upgrade(Request),
     DoNothing,
     DrainWriteBuf,
 }
 
-impl PartialEq for PollResponse {
-    fn eq(&self, other: &PollResponse) -> bool {
-        match self {
-            PollResponse::DrainWriteBuf => matches!(other, PollResponse::DrainWriteBuf),
-            PollResponse::DoNothing => matches!(other, PollResponse::DoNothing),
-            _ => false,
-        }
-    }
-}
-
 impl<T, S, B, X, U> Dispatcher<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error>,
     S::Response: Into<Response<B>>,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
-    /// Create http/1 dispatcher.
+    /// Create HTTP/1 dispatcher.
     pub(crate) fn new(
-        stream: T,
-        config: ServiceConfig,
-        service: CloneableService<S>,
-        expect: CloneableService<X>,
-        upgrade: Option<CloneableService<U>>,
-        on_connect: Option<Box<dyn DataFactory>>,
-        peer_addr: Option<net::SocketAddr>,
-    ) -> Self {
-        Dispatcher::with_timeout(
-            stream,
-            Codec::new(config.clone()),
-            config,
-            BytesMut::with_capacity(HW_BUFFER_SIZE),
-            None,
-            service,
-            expect,
-            upgrade,
-            on_connect,
-            peer_addr,
-        )
-    }
-
-    /// Create http/1 dispatcher with slow request timeout.
-    pub(crate) fn with_timeout(
         io: T,
-        codec: Codec,
         config: ServiceConfig,
-        read_buf: BytesMut,
-        timeout: Option<Delay>,
-        service: CloneableService<S>,
-        expect: CloneableService<X>,
-        upgrade: Option<CloneableService<U>>,
-        on_connect: Option<Box<dyn DataFactory>>,
+        flow: Rc<HttpFlow<S, X, U>>,
+        on_connect_data: OnConnectData,
         peer_addr: Option<net::SocketAddr>,
     ) -> Self {
-        let keepalive = config.keep_alive_enabled();
-        let flags = if keepalive {
+        let flags = if config.keep_alive_enabled() {
             Flags::KEEPALIVE
         } else {
             Flags::empty()
         };
 
         // keep-alive timer
-        let (ka_expire, ka_timer) = if let Some(delay) = timeout {
-            (delay.deadline(), Some(delay))
-        } else if let Some(delay) = config.keep_alive_timer() {
-            (delay.deadline(), Some(delay))
-        } else {
-            (config.now(), None)
+        let (ka_expire, ka_timer) = match config.keep_alive_timer() {
+            Some(delay) => (delay.deadline(), Some(delay)),
+            None => (config.now(), None),
         };
 
         Dispatcher {
             inner: DispatcherState::Normal(InnerDispatcher {
+                read_buf: BytesMut::with_capacity(HW_BUFFER_SIZE),
                 write_buf: BytesMut::with_capacity(HW_BUFFER_SIZE),
                 payload: None,
                 state: State::None,
                 error: None,
                 messages: VecDeque::new(),
                 io: Some(io),
-                codec,
-                read_buf,
-                service,
-                expect,
-                upgrade,
-                on_connect,
+                codec: Codec::new(config),
+                flow,
+                on_connect_data,
                 flags,
                 peer_addr,
                 ka_expire,
                 ka_timer,
             }),
+
+            #[cfg(test)]
+            poll_count: 0,
         }
     }
 }
@@ -246,20 +205,17 @@ where
 impl<T, S, B, X, U> InnerDispatcher<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error>,
     S::Response: Into<Response<B>>,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
     fn can_read(&self, cx: &mut Context<'_>) -> bool {
-        if self
-            .flags
-            .intersects(Flags::READ_DISCONNECT | Flags::UPGRADE)
-        {
+        if self.flags.contains(Flags::READ_DISCONNECT) {
             false
         } else if let Some(ref info) = self.payload {
             info.need_read(cx) == PayloadStatus::Read
@@ -278,62 +234,48 @@ where
         }
     }
 
-    /// Flush stream
-    ///
-    /// true - got WouldBlock
-    /// false - didn't get WouldBlock
     fn poll_flush(
         self: Pin<&mut Self>,
         cx: &mut Context<'_>,
-    ) -> Result<bool, DispatchError> {
-        if self.write_buf.is_empty() {
-            return Ok(false);
-        }
-
-        let len = self.write_buf.len();
-        let mut written = 0;
+    ) -> Poll<Result<(), io::Error>> {
         let InnerDispatcherProj { io, write_buf, .. } = self.project();
         let mut io = Pin::new(io.as_mut().unwrap());
+
+        let len = write_buf.len();
+        let mut written = 0;
+
         while written < len {
-            match io.as_mut().poll_write(cx, &write_buf[written..]) {
-                Poll::Ready(Ok(0)) => {
-                    return Err(DispatchError::Io(io::Error::new(
+            match io.as_mut().poll_write(cx, &write_buf[written..])? {
+                Poll::Ready(0) => {
+                    return Poll::Ready(Err(io::Error::new(
                         io::ErrorKind::WriteZero,
                         "",
-                    )));
-                }
-                Poll::Ready(Ok(n)) => {
-                    written += n;
+                    )))
                 }
+                Poll::Ready(n) => written += n,
                 Poll::Pending => {
-                    if written > 0 {
-                        write_buf.advance(written);
-                    }
-                    return Ok(true);
+                    write_buf.advance(written);
+                    return Poll::Pending;
                 }
-                Poll::Ready(Err(err)) => return Err(DispatchError::Io(err)),
             }
         }
 
-        if written == write_buf.len() {
-            // SAFETY: setting length to 0 is safe
-            // skips one length check vs truncate
-            unsafe { write_buf.set_len(0) }
-        } else {
-            write_buf.advance(written);
-        }
+        // everything has written to io. clear buffer.
+        write_buf.clear();
 
-        Ok(false)
+        // flush the io and check if get blocked.
+        io.poll_flush(cx)
     }
 
     fn send_response(
         self: Pin<&mut Self>,
         message: Response<()>,
         body: ResponseBody<B>,
-    ) -> Result<State<S, B, X>, DispatchError> {
+    ) -> Result<(), DispatchError> {
+        let size = body.size();
         let mut this = self.project();
         this.codec
-            .encode(Message::Item((message, body.size())), &mut this.write_buf)
+            .encode(Message::Item((message, size)), &mut this.write_buf)
             .map_err(|err| {
                 if let Some(mut payload) = this.payload.take() {
                     payload.set_error(PayloadError::Incomplete(None));
@@ -342,10 +284,11 @@ where
             })?;
 
         this.flags.set(Flags::KEEPALIVE, this.codec.keepalive());
-        match body.size() {
-            BodySize::None | BodySize::Empty => Ok(State::None),
-            _ => Ok(State::SendPayload(body)),
-        }
+        match size {
+            BodySize::None | BodySize::Empty => this.state.set(State::None),
+            _ => this.state.set(State::SendPayload(body)),
+        };
+        Ok(())
     }
 
     fn send_continue(self: Pin<&mut Self>) {
@@ -358,157 +301,201 @@ where
         mut self: Pin<&mut Self>,
         cx: &mut Context<'_>,
     ) -> Result<PollResponse, DispatchError> {
-        loop {
+        'res: loop {
             let mut this = self.as_mut().project();
-            let state = match this.state.project() {
+            match this.state.as_mut().project() {
+                // no future is in InnerDispatcher state. pop next message.
                 StateProj::None => match this.messages.pop_front() {
+                    // handle request message.
                     Some(DispatcherMessage::Item(req)) => {
-                        Some(self.as_mut().handle_request(req, cx)?)
+                        // Handle `EXPECT: 100-Continue` header
+                        if req.head().expect() {
+                            // set InnerDispatcher state and continue loop to poll it.
+                            let task = this.flow.expect.call(req);
+                            this.state.set(State::ExpectCall(task));
+                        } else {
+                            // the same as expect call.
+                            let task = this.flow.service.call(req);
+                            this.state.set(State::ServiceCall(task));
+                        };
                     }
-                    Some(DispatcherMessage::Error(res)) => Some(
+
+                    // handle error message.
+                    Some(DispatcherMessage::Error(res)) => {
+                        // send_response would update InnerDispatcher state to SendPayload or
+                        // None(If response body is empty).
+                        // continue loop to poll it.
                         self.as_mut()
-                            .send_response(res, ResponseBody::Other(Body::Empty))?,
-                    ),
+                            .send_response(res, ResponseBody::Other(Body::Empty))?;
+                    }
+
+                    // return with upgrade request and poll it exclusively.
                     Some(DispatcherMessage::Upgrade(req)) => {
                         return Ok(PollResponse::Upgrade(req));
                     }
-                    None => None,
+
+                    // all messages are dealt with.
+                    None => return Ok(PollResponse::DoNothing),
                 },
-                StateProj::ExpectCall(fut) => match fut.as_mut().poll(cx) {
-                    Poll::Ready(Ok(req)) => {
-                        self.as_mut().send_continue();
-                        this = self.as_mut().project();
-                        this.state
-                            .set(State::ServiceCall(Box::pin(this.service.call(req))));
-                        continue;
-                    }
-                    Poll::Ready(Err(e)) => {
-                        let res: Response = e.into().into();
-                        let (res, body) = res.replace_body(());
-                        Some(self.as_mut().send_response(res, body.into_body())?)
-                    }
-                    Poll::Pending => None,
-                },
-                StateProj::ServiceCall(fut) => match fut.as_mut().poll(cx) {
+                StateProj::ServiceCall(fut) => match fut.poll(cx) {
+                    // service call resolved. send response.
                     Poll::Ready(Ok(res)) => {
                         let (res, body) = res.into().replace_body(());
-                        let state = self.as_mut().send_response(res, body)?;
-                        this = self.as_mut().project();
-                        this.state.set(state);
-                        continue;
+                        self.as_mut().send_response(res, body)?;
                     }
-                    Poll::Ready(Err(e)) => {
-                        let res: Response = e.into().into();
+
+                    // send service call error as response
+                    Poll::Ready(Err(err)) => {
+                        let res: Response = err.into().into();
                         let (res, body) = res.replace_body(());
-                        Some(self.as_mut().send_response(res, body.into_body())?)
+                        self.as_mut().send_response(res, body.into_body())?;
                     }
-                    Poll::Pending => None,
-                },
-                StateProj::SendPayload(mut stream) => {
-                    loop {
-                        if this.write_buf.len() < HW_BUFFER_SIZE {
-                            match stream.as_mut().poll_next(cx) {
-                                Poll::Ready(Some(Ok(item))) => {
-                                    this.codec.encode(
-                                        Message::Chunk(Some(item)),
-                                        &mut this.write_buf,
-                                    )?;
-                                    continue;
-                                }
-                                Poll::Ready(None) => {
-                                    this.codec.encode(
-                                        Message::Chunk(None),
-                                        &mut this.write_buf,
-                                    )?;
-                                    this = self.as_mut().project();
-                                    this.state.set(State::None);
-                                }
-                                Poll::Ready(Some(Err(_))) => {
-                                    return Err(DispatchError::Unknown)
-                                }
-                                Poll::Pending => return Ok(PollResponse::DoNothing),
-                            }
-                        } else {
-                            return Ok(PollResponse::DrainWriteBuf);
+
+                    // service call pending and could be waiting for more chunk messages.
+                    // (pipeline message limit and/or payload can_read limit)
+                    Poll::Pending => {
+                        // no new message is decoded and no new payload is feed.
+                        // nothing to do except waiting for new incoming data from client.
+                        if !self.as_mut().poll_request(cx)? {
+                            return Ok(PollResponse::DoNothing);
                         }
-                        break;
+                        // otherwise keep loop.
                     }
-                    continue;
-                }
-            };
+                },
 
-            this = self.as_mut().project();
+                StateProj::SendPayload(mut stream) => {
+                    // keep populate writer buffer until buffer size limit hit,
+                    // get blocked or finished.
+                    while this.write_buf.len() < super::payload::MAX_BUFFER_SIZE {
+                        match stream.as_mut().poll_next(cx) {
+                            Poll::Ready(Some(Ok(item))) => {
+                                this.codec.encode(
+                                    Message::Chunk(Some(item)),
+                                    &mut this.write_buf,
+                                )?;
+                            }
 
-            // set new state
-            if let Some(state) = state {
-                this.state.set(state);
-                if !self.state.is_empty() {
-                    continue;
-                }
-            } else {
-                // if read-backpressure is enabled and we consumed some data.
-                // we may read more data and retry
-                if self.state.is_call() {
-                    if self.as_mut().poll_request(cx)? {
-                        continue;
+                            Poll::Ready(None) => {
+                                this.codec
+                                    .encode(Message::Chunk(None), &mut this.write_buf)?;
+                                // payload stream finished.
+                                // set state to None and handle next message
+                                this.state.set(State::None);
+                                continue 'res;
+                            }
+
+                            Poll::Ready(Some(Err(err))) => {
+                                return Err(DispatchError::Service(err))
+                            }
+
+                            Poll::Pending => return Ok(PollResponse::DoNothing),
+                        }
                     }
-                } else if !self.messages.is_empty() {
-                    continue;
+                    // buffer is beyond max size.
+                    // return and try to write the whole buffer to io stream.
+                    return Ok(PollResponse::DrainWriteBuf);
                 }
+
+                StateProj::ExpectCall(fut) => match fut.poll(cx) {
+                    // expect resolved. write continue to buffer and set InnerDispatcher state
+                    // to service call.
+                    Poll::Ready(Ok(req)) => {
+                        this.write_buf
+                            .extend_from_slice(b"HTTP/1.1 100 Continue\r\n\r\n");
+                        let fut = this.flow.service.call(req);
+                        this.state.set(State::ServiceCall(fut));
+                    }
+                    // send expect error as response
+                    Poll::Ready(Err(err)) => {
+                        let res: Response = err.into().into();
+                        let (res, body) = res.replace_body(());
+                        self.as_mut().send_response(res, body.into_body())?;
+                    }
+                    // expect must be solved before progress can be made.
+                    Poll::Pending => return Ok(PollResponse::DoNothing),
+                },
             }
-            break;
         }
-
-        Ok(PollResponse::DoNothing)
     }
 
     fn handle_request(
         mut self: Pin<&mut Self>,
         req: Request,
         cx: &mut Context<'_>,
-    ) -> Result<State<S, B, X>, DispatchError> {
+    ) -> Result<(), DispatchError> {
         // Handle `EXPECT: 100-Continue` header
-        let req = if req.head().expect() {
-            let mut task = Box::pin(self.as_mut().project().expect.call(req));
-            match task.as_mut().poll(cx) {
-                Poll::Ready(Ok(req)) => {
-                    self.as_mut().send_continue();
-                    req
-                }
-                Poll::Pending => return Ok(State::ExpectCall(task)),
-                Poll::Ready(Err(e)) => {
-                    let e = e.into();
-                    let res: Response = e.into();
-                    let (res, body) = res.replace_body(());
-                    return self.send_response(res, body.into_body());
-                }
-            }
+        if req.head().expect() {
+            // set dispatcher state so the future is pinned.
+            let mut this = self.as_mut().project();
+            let task = this.flow.expect.call(req);
+            this.state.set(State::ExpectCall(task));
         } else {
-            req
+            // the same as above.
+            let mut this = self.as_mut().project();
+            let task = this.flow.service.call(req);
+            this.state.set(State::ServiceCall(task));
         };
 
-        // Call service
-        let mut task = Box::pin(self.as_mut().project().service.call(req));
-        match task.as_mut().poll(cx) {
-            Poll::Ready(Ok(res)) => {
-                let (res, body) = res.into().replace_body(());
-                self.send_response(res, body)
-            }
-            Poll::Pending => Ok(State::ServiceCall(task)),
-            Poll::Ready(Err(e)) => {
-                let res: Response = e.into().into();
-                let (res, body) = res.replace_body(());
-                self.send_response(res, body.into_body())
+        // eagerly poll the future for once(or twice if expect is resolved immediately).
+        loop {
+            match self.as_mut().project().state.project() {
+                StateProj::ExpectCall(fut) => {
+                    match fut.poll(cx) {
+                        // expect is resolved. continue loop and poll the service call branch.
+                        Poll::Ready(Ok(req)) => {
+                            self.as_mut().send_continue();
+                            let mut this = self.as_mut().project();
+                            let task = this.flow.service.call(req);
+                            this.state.set(State::ServiceCall(task));
+                            continue;
+                        }
+                        // future is pending. return Ok(()) to notify that a new state is
+                        // set  and the outer loop should be continue.
+                        Poll::Pending => return Ok(()),
+                        // future is error. send response and return a result. On success
+                        // to notify the dispatcher a new state is set and the outer loop
+                        // should be continue.
+                        Poll::Ready(Err(err)) => {
+                            let err = err.into();
+                            let res: Response = err.into();
+                            let (res, body) = res.replace_body(());
+                            return self.send_response(res, body.into_body());
+                        }
+                    }
+                }
+                StateProj::ServiceCall(fut) => {
+                    // return no matter the service call future's result.
+                    return match fut.poll(cx) {
+                        // future is resolved. send response and return a result. On success
+                        // to notify the dispatcher a new state is set and the outer loop
+                        // should be continue.
+                        Poll::Ready(Ok(res)) => {
+                            let (res, body) = res.into().replace_body(());
+                            self.send_response(res, body)
+                        }
+                        // see the comment on ExpectCall state branch's Pending.
+                        Poll::Pending => Ok(()),
+                        // see the comment on ExpectCall state branch's Ready(Err(err)).
+                        Poll::Ready(Err(err)) => {
+                            let res: Response = err.into().into();
+                            let (res, body) = res.replace_body(());
+                            self.send_response(res, body.into_body())
+                        }
+                    };
+                }
+                _ => unreachable!(
+                    "State must be set to ServiceCall or ExceptCall in handle_request"
+                ),
             }
         }
     }
 
-    /// Process one incoming requests
-    pub(self) fn poll_request(
+    /// Process one incoming request.
+    fn poll_request(
         mut self: Pin<&mut Self>,
         cx: &mut Context<'_>,
     ) -> Result<bool, DispatchError> {
-        // limit a mount of non processed requests
+        // limit amount of non-processed requests
         if self.messages.len() >= MAX_PIPELINED_MESSAGES || !self.can_read(cx) {
             return Ok(false);
         }
@@ -523,31 +510,46 @@ where
 
                     match msg {
                         Message::Item(mut req) => {
-                            let pl = this.codec.message_type();
                             req.head_mut().peer_addr = *this.peer_addr;
 
-                            // set on_connect data
-                            if let Some(ref on_connect) = this.on_connect {
-                                on_connect.set(&mut req.extensions_mut());
+                            // merge on_connect_ext data into request extensions
+                            this.on_connect_data.merge_into(&mut req);
+
+                            match this.codec.message_type() {
+                                // Request is upgradable. add upgrade message and break.
+                                // everything remain in read buffer would be handed to
+                                // upgraded Request.
+                                MessageType::Stream if this.flow.upgrade.is_some() => {
+                                    this.messages
+                                        .push_back(DispatcherMessage::Upgrade(req));
+                                    break;
+                                }
+
+                                // Request is not upgradable.
+                                MessageType::Payload | MessageType::Stream => {
+                                    /*
+                                    PayloadSender and Payload are smart pointers share the
+                                    same state.
+                                    PayloadSender is attached to dispatcher and used to sink
+                                    new chunked request data to state.
+                                    Payload is attached to Request and passed to Service::call
+                                    where the state can be collected and consumed.
+                                    */
+                                    let (ps, pl) = Payload::create(false);
+                                    let (req1, _) =
+                                        req.replace_payload(crate::Payload::H1(pl));
+                                    req = req1;
+                                    *this.payload = Some(ps);
+                                }
+
+                                // Request has no payload.
+                                MessageType::None => {}
                             }
 
-                            if pl == MessageType::Stream && this.upgrade.is_some() {
-                                this.messages.push_back(DispatcherMessage::Upgrade(req));
-                                break;
-                            }
-                            if pl == MessageType::Payload || pl == MessageType::Stream {
-                                let (ps, pl) = Payload::create(false);
-                                let (req1, _) =
-                                    req.replace_payload(crate::Payload::H1(pl));
-                                req = req1;
-                                *this.payload = Some(ps);
-                            }
-
-                            // handle request early
+                            // handle request early when no future in InnerDispatcher state.
                             if this.state.is_empty() {
-                                let state = self.as_mut().handle_request(req, cx)?;
+                                self.as_mut().handle_request(req, cx)?;
                                 this = self.as_mut().project();
-                                this.state.set(state);
                             } else {
                                 this.messages.push_back(DispatcherMessage::Item(req));
                             }
@@ -582,14 +584,28 @@ where
                         }
                     }
                 }
+                // decode is partial and buffer is not full yet.
+                // break and wait for more read.
                 Ok(None) => break,
-                Err(ParseError::Io(e)) => {
+                Err(ParseError::Io(err)) => {
                     self.as_mut().client_disconnected();
                     this = self.as_mut().project();
-                    *this.error = Some(DispatchError::Io(e));
+                    *this.error = Some(DispatchError::Io(err));
                     break;
                 }
-                Err(e) => {
+                Err(ParseError::TooLarge) => {
+                    if let Some(mut payload) = this.payload.take() {
+                        payload.set_error(PayloadError::Overflow);
+                    }
+                    // Requests overflow buffer size should be responded with 431
+                    this.messages.push_back(DispatcherMessage::Error(
+                        Response::RequestHeaderFieldsTooLarge().finish().drop_body(),
+                    ));
+                    this.flags.insert(Flags::READ_DISCONNECT);
+                    *this.error = Some(ParseError::TooLarge.into());
+                    break;
+                }
+                Err(err) => {
                     if let Some(mut payload) = this.payload.take() {
                         payload.set_error(PayloadError::EncodingCorrupted);
                     }
@@ -599,7 +615,7 @@ where
                         Response::BadRequest().finish().drop_body(),
                     ));
                     this.flags.insert(Flags::READ_DISCONNECT);
-                    *this.error = Some(e.into());
+                    *this.error = Some(err.into());
                     break;
                 }
             }
@@ -619,93 +635,203 @@ where
         cx: &mut Context<'_>,
     ) -> Result<(), DispatchError> {
         let mut this = self.as_mut().project();
-        if this.ka_timer.is_none() {
-            // shutdown timeout
-            if this.flags.contains(Flags::SHUTDOWN) {
-                if let Some(interval) = this.codec.config().client_disconnect_timer() {
-                    *this.ka_timer = Some(delay_until(interval));
-                } else {
-                    this.flags.insert(Flags::READ_DISCONNECT);
-                    if let Some(mut payload) = this.payload.take() {
-                        payload.set_error(PayloadError::Incomplete(None));
-                    }
-                    return Ok(());
-                }
-            } else {
-                return Ok(());
-            }
-        }
 
-        match Pin::new(&mut this.ka_timer.as_mut().unwrap()).poll(cx) {
-            Poll::Ready(()) => {
-                // if we get timeout during shutdown, drop connection
+        // when a branch is not explicit return early it's meant to fall through
+        // and return as Ok(())
+        match this.ka_timer.as_mut().as_pin_mut() {
+            None => {
+                // conditionally go into shutdown timeout
                 if this.flags.contains(Flags::SHUTDOWN) {
-                    return Err(DispatchError::DisconnectTimeout);
-                } else if this.ka_timer.as_mut().unwrap().deadline() >= *this.ka_expire {
-                    // check for any outstanding tasks
-                    if this.state.is_empty() && this.write_buf.is_empty() {
-                        if this.flags.contains(Flags::STARTED) {
-                            trace!("Keep-alive timeout, close connection");
-                            this.flags.insert(Flags::SHUTDOWN);
+                    if let Some(deadline) = this.codec.config().client_disconnect_timer()
+                    {
+                        // write client disconnect time out and poll again to
+                        // go into Some<Pin<&mut Sleep>> branch
+                        this.ka_timer.set(Some(sleep_until(deadline)));
+                        return self.poll_keepalive(cx);
+                    } else {
+                        this.flags.insert(Flags::READ_DISCONNECT);
+                        if let Some(mut payload) = this.payload.take() {
+                            payload.set_error(PayloadError::Incomplete(None));
+                        }
+                    }
+                }
+            }
+            Some(mut timer) => {
+                // only operate when keep-alive timer is resolved.
+                if timer.as_mut().poll(cx).is_ready() {
+                    // got timeout during shutdown, drop connection
+                    if this.flags.contains(Flags::SHUTDOWN) {
+                        return Err(DispatchError::DisconnectTimeout);
+                    // exceed deadline. check for any outstanding tasks
+                    } else if timer.deadline() >= *this.ka_expire {
+                        // have no task at hand.
+                        if this.state.is_empty() && this.write_buf.is_empty() {
+                            if this.flags.contains(Flags::STARTED) {
+                                trace!("Keep-alive timeout, close connection");
+                                this.flags.insert(Flags::SHUTDOWN);
 
-                            // start shutdown timer
-                            if let Some(deadline) =
-                                this.codec.config().client_disconnect_timer()
-                            {
-                                if let Some(mut timer) = this.ka_timer.as_mut() {
-                                    timer.reset(deadline);
-                                    let _ = Pin::new(&mut timer).poll(cx);
+                                // start shutdown timeout
+                                if let Some(deadline) =
+                                    this.codec.config().client_disconnect_timer()
+                                {
+                                    timer.as_mut().reset(deadline);
+                                    let _ = timer.poll(cx);
+                                } else {
+                                    // no shutdown timeout, drop socket
+                                    this.flags.insert(Flags::WRITE_DISCONNECT);
                                 }
                             } else {
-                                // no shutdown timeout, drop socket
-                                this.flags.insert(Flags::WRITE_DISCONNECT);
-                                return Ok(());
+                                // timeout on first request (slow request) return 408
+                                if !this.flags.contains(Flags::STARTED) {
+                                    trace!("Slow request timeout");
+                                    let _ = self.as_mut().send_response(
+                                        Response::RequestTimeout().finish().drop_body(),
+                                        ResponseBody::Other(Body::Empty),
+                                    );
+                                    this = self.project();
+                                } else {
+                                    trace!("Keep-alive connection timeout");
+                                }
+                                this.flags.insert(Flags::STARTED | Flags::SHUTDOWN);
+                                this.state.set(State::None);
                             }
-                        } else {
-                            // timeout on first request (slow request) return 408
-                            if !this.flags.contains(Flags::STARTED) {
-                                trace!("Slow request timeout");
-                                let _ = self.as_mut().send_response(
-                                    Response::RequestTimeout().finish().drop_body(),
-                                    ResponseBody::Other(Body::Empty),
-                                );
-                                this = self.as_mut().project();
-                            } else {
-                                trace!("Keep-alive connection timeout");
-                            }
-                            this.flags.insert(Flags::STARTED | Flags::SHUTDOWN);
-                            this.state.set(State::None);
-                        }
-                    } else if let Some(deadline) =
-                        this.codec.config().keep_alive_expire()
-                    {
-                        if let Some(mut timer) = this.ka_timer.as_mut() {
-                            timer.reset(deadline);
-                            let _ = Pin::new(&mut timer).poll(cx);
+                        // still have unfinished task. try to reset and register keep-alive.
+                        } else if let Some(deadline) =
+                            this.codec.config().keep_alive_expire()
+                        {
+                            timer.as_mut().reset(deadline);
+                            let _ = timer.poll(cx);
                         }
+                    // timer resolved but still have not met the keep-alive expire deadline.
+                    // reset and register for later wakeup.
+                    } else {
+                        timer.as_mut().reset(*this.ka_expire);
+                        let _ = timer.poll(cx);
                     }
-                } else if let Some(mut timer) = this.ka_timer.as_mut() {
-                    timer.reset(*this.ka_expire);
-                    let _ = Pin::new(&mut timer).poll(cx);
                 }
             }
-            Poll::Pending => (),
         }
-
         Ok(())
     }
+
+    /// Returns true when io stream can be disconnected after write to it.
+    ///
+    /// It covers these conditions:
+    ///
+    /// - `std::io::ErrorKind::ConnectionReset` after partial read.
+    /// - all data read done.
+    #[inline(always)]
+    fn read_available(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Result<bool, DispatchError> {
+        let this = self.project();
+
+        if this.flags.contains(Flags::READ_DISCONNECT) {
+            return Ok(false);
+        };
+
+        let mut io = Pin::new(this.io.as_mut().unwrap());
+
+        let mut read_some = false;
+
+        loop {
+            // Return early when read buf exceed decoder's max buffer size.
+            if this.read_buf.len() >= super::decoder::MAX_BUFFER_SIZE {
+                /*
+                 At this point it's not known IO stream is still scheduled
+                 to be waked up. so force wake up dispatcher just in case.
+
+                 Reason:
+                 AsyncRead mostly would only have guarantee wake up
+                 when the poll_read return Poll::Pending.
+
+                 Case:
+                 When read_buf is beyond max buffer size the early return
+                 could be successfully be parsed as a new Request.
+                 This case would not generate ParseError::TooLarge
+                 and at this point IO stream is not fully read to Pending
+                 and would result in dispatcher stuck until timeout (KA)
+
+                 Note:
+                 This is a perf choice to reduce branch on
+                 <Request as MessageType>::decode.
+
+                 A Request head too large to parse is only checked on
+                 httparse::Status::Partial condition.
+                */
+                if this.payload.is_none() {
+                    /*
+                    When dispatcher has a payload the responsibility of
+                    wake up it would be shift to h1::payload::Payload.
+
+                    Reason:
+                    Self wake up when there is payload would waste poll
+                    and/or result in over read.
+
+                    Case:
+                    When payload is (partial) dropped by user there is
+                    no need to do read anymore.
+                    At this case read_buf could always remain beyond
+                    MAX_BUFFER_SIZE and self wake up would be busy poll
+                    dispatcher and waste resource.
+
+                    */
+                    cx.waker().wake_by_ref();
+                }
+
+                return Ok(false);
+            }
+
+            // grow buffer if necessary.
+            let remaining = this.read_buf.capacity() - this.read_buf.len();
+            if remaining < LW_BUFFER_SIZE {
+                this.read_buf.reserve(HW_BUFFER_SIZE - remaining);
+            }
+
+            match actix_codec::poll_read_buf(io.as_mut(), cx, this.read_buf) {
+                Poll::Ready(Ok(n)) => {
+                    if n == 0 {
+                        return Ok(true);
+                    }
+                    read_some = true;
+                }
+                Poll::Pending => return Ok(false),
+                Poll::Ready(Err(err)) => {
+                    return match err.kind() {
+                        io::ErrorKind::WouldBlock => Ok(false),
+                        io::ErrorKind::ConnectionReset if read_some => Ok(true),
+                        _ => Err(DispatchError::Io(err)),
+                    }
+                }
+            }
+        }
+    }
+
+    /// call upgrade service with request.
+    fn upgrade(self: Pin<&mut Self>, req: Request) -> U::Future {
+        let this = self.project();
+        let mut parts = FramedParts::with_read_buf(
+            this.io.take().unwrap(),
+            mem::take(this.codec),
+            mem::take(this.read_buf),
+        );
+        parts.write_buf = mem::take(this.write_buf);
+        let framed = Framed::from_parts(parts);
+        this.flow.upgrade.as_ref().unwrap().call((req, framed))
+    }
 }
 
 impl<T, S, B, X, U> Future for Dispatcher<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error>,
     S::Response: Into<Response<B>>,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
     type Output = Result<(), DispatchError>;
@@ -713,6 +839,12 @@ where
     #[inline]
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let this = self.as_mut().project();
+
+        #[cfg(test)]
+        {
+            *this.poll_count += 1;
+        }
+
         match this.inner.project() {
             DispatcherStateProj::Normal(mut inner) => {
                 inner.as_mut().poll_keepalive(cx)?;
@@ -721,79 +853,51 @@ where
                     if inner.flags.contains(Flags::WRITE_DISCONNECT) {
                         Poll::Ready(Ok(()))
                     } else {
-                        // flush buffer
-                        inner.as_mut().poll_flush(cx)?;
-                        if !inner.write_buf.is_empty() || inner.io.is_none() {
-                            Poll::Pending
-                        } else {
-                            match Pin::new(inner.project().io)
-                                .as_pin_mut()
-                                .unwrap()
-                                .poll_shutdown(cx)
-                            {
-                                Poll::Ready(res) => {
-                                    Poll::Ready(res.map_err(DispatchError::from))
-                                }
-                                Poll::Pending => Poll::Pending,
-                            }
-                        }
+                        // flush buffer and wait on blocked.
+                        ready!(inner.as_mut().poll_flush(cx))?;
+                        Pin::new(inner.project().io.as_mut().unwrap())
+                            .poll_shutdown(cx)
+                            .map_err(DispatchError::from)
                     }
                 } else {
-                    // read socket into a buf
-                    let should_disconnect =
-                        if !inner.flags.contains(Flags::READ_DISCONNECT) {
-                            let mut inner_p = inner.as_mut().project();
-                            read_available(
-                                cx,
-                                inner_p.io.as_mut().unwrap(),
-                                &mut inner_p.read_buf,
-                            )?
-                        } else {
-                            None
-                        };
+                    // read from io stream and fill read buffer.
+                    let should_disconnect = inner.as_mut().read_available(cx)?;
 
                     inner.as_mut().poll_request(cx)?;
-                    if let Some(true) = should_disconnect {
-                        let inner_p = inner.as_mut().project();
-                        inner_p.flags.insert(Flags::READ_DISCONNECT);
-                        if let Some(mut payload) = inner_p.payload.take() {
+
+                    // io stream should to be closed.
+                    if should_disconnect {
+                        let inner = inner.as_mut().project();
+                        inner.flags.insert(Flags::READ_DISCONNECT);
+                        if let Some(mut payload) = inner.payload.take() {
                             payload.feed_eof();
                         }
                     };
 
                     loop {
-                        let inner_p = inner.as_mut().project();
-                        let remaining =
-                            inner_p.write_buf.capacity() - inner_p.write_buf.len();
-                        if remaining < LW_BUFFER_SIZE {
-                            inner_p.write_buf.reserve(HW_BUFFER_SIZE - remaining);
-                        }
-                        let result = inner.as_mut().poll_response(cx)?;
-                        let drain = result == PollResponse::DrainWriteBuf;
-
-                        // switch to upgrade handler
-                        if let PollResponse::Upgrade(req) = result {
-                            let inner_p = inner.as_mut().project();
-                            let mut parts = FramedParts::with_read_buf(
-                                inner_p.io.take().unwrap(),
-                                std::mem::take(inner_p.codec),
-                                std::mem::take(inner_p.read_buf),
-                            );
-                            parts.write_buf = std::mem::take(inner_p.write_buf);
-                            let framed = Framed::from_parts(parts);
-                            let upgrade =
-                                inner_p.upgrade.take().unwrap().call((req, framed));
-                            self.as_mut()
-                                .project()
-                                .inner
-                                .set(DispatcherState::Upgrade(Box::pin(upgrade)));
-                            return self.poll(cx);
-                        }
+                        // poll_response and populate write buffer.
+                        // drain indicate if write buffer should be emptied before next run.
+                        let drain = match inner.as_mut().poll_response(cx)? {
+                            PollResponse::DrainWriteBuf => true,
+                            PollResponse::DoNothing => false,
+                            // upgrade request and goes Upgrade variant of DispatcherState.
+                            PollResponse::Upgrade(req) => {
+                                let upgrade = inner.upgrade(req);
+                                self.as_mut()
+                                    .project()
+                                    .inner
+                                    .set(DispatcherState::Upgrade(upgrade));
+                                return self.poll(cx);
+                            }
+                        };
 
                         // we didn't get WouldBlock from write operation,
-                        // so data get written to kernel completely (OSX)
+                        // so data get written to kernel completely (macOS)
                         // and we have to write again otherwise response can get stuck
-                        if inner.as_mut().poll_flush(cx)? || !drain {
+                        //
+                        // TODO: what? is WouldBlock good or bad?
+                        // want to find a reference for this macOS behavior
+                        if inner.as_mut().poll_flush(cx)?.is_pending() || !drain {
                             break;
                         }
                     }
@@ -834,7 +938,7 @@ where
                     }
                 }
             }
-            DispatcherStateProj::Upgrade(fut) => fut.as_mut().poll(cx).map_err(|e| {
+            DispatcherStateProj::Upgrade(fut) => fut.poll(cx).map_err(|e| {
                 error!("Upgrade handler error: {}", e);
                 DispatchError::Upgrade
             }),
@@ -842,106 +946,374 @@ where
     }
 }
 
-fn read_available<T>(
-    cx: &mut Context<'_>,
-    io: &mut T,
-    buf: &mut BytesMut,
-) -> Result<Option<bool>, io::Error>
-where
-    T: AsyncRead + Unpin,
-{
-    let mut read_some = false;
-
-    loop {
-        // If buf is full return but do not disconnect since
-        // there is more reading to be done
-        if buf.len() >= HW_BUFFER_SIZE {
-            return Ok(Some(false));
-        }
-
-        let remaining = buf.capacity() - buf.len();
-        if remaining < LW_BUFFER_SIZE {
-            buf.reserve(HW_BUFFER_SIZE - remaining);
-        }
-
-        match read(cx, io, buf) {
-            Poll::Pending => {
-                return if read_some { Ok(Some(false)) } else { Ok(None) };
-            }
-            Poll::Ready(Ok(n)) => {
-                if n == 0 {
-                    return Ok(Some(true));
-                } else {
-                    read_some = true;
-                }
-            }
-            Poll::Ready(Err(e)) => {
-                return if e.kind() == io::ErrorKind::WouldBlock {
-                    if read_some {
-                        Ok(Some(false))
-                    } else {
-                        Ok(None)
-                    }
-                } else if e.kind() == io::ErrorKind::ConnectionReset && read_some {
-                    Ok(Some(true))
-                } else {
-                    Err(e)
-                }
-            }
-        }
-    }
-}
-
-fn read<T>(
-    cx: &mut Context<'_>,
-    io: &mut T,
-    buf: &mut BytesMut,
-) -> Poll<Result<usize, io::Error>>
-where
-    T: AsyncRead + Unpin,
-{
-    Pin::new(io).poll_read_buf(cx, buf)
-}
-
 #[cfg(test)]
 mod tests {
-    use actix_service::IntoService;
-    use futures_util::future::{lazy, ok};
+    use std::str;
+
+    use actix_service::fn_service;
+    use futures_util::future::{lazy, ready};
 
     use super::*;
-    use crate::error::Error;
-    use crate::h1::{ExpectHandler, UpgradeHandler};
     use crate::test::TestBuffer;
+    use crate::{error::Error, KeepAlive};
+    use crate::{
+        h1::{ExpectHandler, UpgradeHandler},
+        test::TestSeqBuffer,
+    };
+
+    fn find_slice(haystack: &[u8], needle: &[u8], from: usize) -> Option<usize> {
+        haystack[from..]
+            .windows(needle.len())
+            .position(|window| window == needle)
+    }
+
+    fn stabilize_date_header(payload: &mut [u8]) {
+        let mut from = 0;
+
+        while let Some(pos) = find_slice(&payload, b"date", from) {
+            payload[(from + pos)..(from + pos + 35)]
+                .copy_from_slice(b"date: Thu, 01 Jan 1970 12:34:56 UTC");
+            from += 35;
+        }
+    }
+
+    fn ok_service() -> impl Service<Request, Response = Response, Error = Error> {
+        fn_service(|_req: Request| ready(Ok::<_, Error>(Response::Ok().finish())))
+    }
+
+    fn echo_path_service() -> impl Service<Request, Response = Response, Error = Error> {
+        fn_service(|req: Request| {
+            let path = req.path().as_bytes();
+            ready(Ok::<_, Error>(Response::Ok().body(Body::from_slice(path))))
+        })
+    }
+
+    fn echo_payload_service() -> impl Service<Request, Response = Response, Error = Error>
+    {
+        fn_service(|mut req: Request| {
+            Box::pin(async move {
+                use futures_util::stream::StreamExt as _;
+
+                let mut pl = req.take_payload();
+                let mut body = BytesMut::new();
+                while let Some(chunk) = pl.next().await {
+                    body.extend_from_slice(chunk.unwrap().chunk())
+                }
+
+                Ok::<_, Error>(Response::Ok().body(body))
+            })
+        })
+    }
 
     #[actix_rt::test]
     async fn test_req_parse_err() {
         lazy(|cx| {
             let buf = TestBuffer::new("GET /test HTTP/1\r\n\r\n");
 
-            let mut h1 = Dispatcher::<_, _, _, _, UpgradeHandler<TestBuffer>>::new(
+            let services = HttpFlow::new(ok_service(), ExpectHandler, None);
+
+            let h1 = Dispatcher::<_, _, _, _, UpgradeHandler>::new(
                 buf,
                 ServiceConfig::default(),
-                CloneableService::new(
-                    (|_| ok::<_, Error>(Response::Ok().finish())).into_service(),
-                ),
-                CloneableService::new(ExpectHandler),
-                None,
-                None,
+                services,
+                OnConnectData::default(),
                 None,
             );
-            match Pin::new(&mut h1).poll(cx) {
+
+            actix_rt::pin!(h1);
+
+            match h1.as_mut().poll(cx) {
                 Poll::Pending => panic!(),
                 Poll::Ready(res) => assert!(res.is_err()),
             }
 
-            if let DispatcherState::Normal(ref mut inner) = h1.inner {
+            if let DispatcherStateProj::Normal(inner) = h1.project().inner.project() {
                 assert!(inner.flags.contains(Flags::READ_DISCONNECT));
                 assert_eq!(
-                    &inner.io.take().unwrap().write_buf[..26],
+                    &inner.project().io.take().unwrap().write_buf[..26],
                     b"HTTP/1.1 400 Bad Request\r\n"
                 );
             }
         })
         .await;
     }
+
+    #[actix_rt::test]
+    async fn test_pipelining() {
+        lazy(|cx| {
+            let buf = TestBuffer::new(
+                "\
+                GET /abcd HTTP/1.1\r\n\r\n\
+                GET /def HTTP/1.1\r\n\r\n\
+                ",
+            );
+
+            let cfg = ServiceConfig::new(KeepAlive::Disabled, 1, 1, false, None);
+
+            let services = HttpFlow::new(echo_path_service(), ExpectHandler, None);
+
+            let h1 = Dispatcher::<_, _, _, _, UpgradeHandler>::new(
+                buf,
+                cfg,
+                services,
+                OnConnectData::default(),
+                None,
+            );
+
+            actix_rt::pin!(h1);
+
+            assert!(matches!(&h1.inner, DispatcherState::Normal(_)));
+
+            match h1.as_mut().poll(cx) {
+                Poll::Pending => panic!("first poll should not be pending"),
+                Poll::Ready(res) => assert!(res.is_ok()),
+            }
+
+            // polls: initial => shutdown
+            assert_eq!(h1.poll_count, 2);
+
+            if let DispatcherStateProj::Normal(inner) = h1.project().inner.project() {
+                let res = &mut inner.project().io.take().unwrap().write_buf[..];
+                stabilize_date_header(res);
+
+                let exp = b"\
+                HTTP/1.1 200 OK\r\n\
+                content-length: 5\r\n\
+                connection: close\r\n\
+                date: Thu, 01 Jan 1970 12:34:56 UTC\r\n\r\n\
+                /abcd\
+                HTTP/1.1 200 OK\r\n\
+                content-length: 4\r\n\
+                connection: close\r\n\
+                date: Thu, 01 Jan 1970 12:34:56 UTC\r\n\r\n\
+                /def\
+                ";
+
+                assert_eq!(res.to_vec(), exp.to_vec());
+            }
+        })
+        .await;
+
+        lazy(|cx| {
+            let buf = TestBuffer::new(
+                "\
+                GET /abcd HTTP/1.1\r\n\r\n\
+                GET /def HTTP/1\r\n\r\n\
+                ",
+            );
+
+            let cfg = ServiceConfig::new(KeepAlive::Disabled, 1, 1, false, None);
+
+            let services = HttpFlow::new(echo_path_service(), ExpectHandler, None);
+
+            let h1 = Dispatcher::<_, _, _, _, UpgradeHandler>::new(
+                buf,
+                cfg,
+                services,
+                OnConnectData::default(),
+                None,
+            );
+
+            actix_rt::pin!(h1);
+
+            assert!(matches!(&h1.inner, DispatcherState::Normal(_)));
+
+            match h1.as_mut().poll(cx) {
+                Poll::Pending => panic!("first poll should not be pending"),
+                Poll::Ready(res) => assert!(res.is_err()),
+            }
+
+            // polls: initial => shutdown
+            assert_eq!(h1.poll_count, 1);
+
+            if let DispatcherStateProj::Normal(inner) = h1.project().inner.project() {
+                let res = &mut inner.project().io.take().unwrap().write_buf[..];
+                stabilize_date_header(res);
+
+                let exp = b"\
+                HTTP/1.1 200 OK\r\n\
+                content-length: 5\r\n\
+                connection: close\r\n\
+                date: Thu, 01 Jan 1970 12:34:56 UTC\r\n\r\n\
+                /abcd\
+                HTTP/1.1 400 Bad Request\r\n\
+                content-length: 0\r\n\
+                connection: close\r\n\
+                date: Thu, 01 Jan 1970 12:34:56 UTC\r\n\r\n\
+                ";
+
+                assert_eq!(res.to_vec(), exp.to_vec());
+            }
+        })
+        .await;
+    }
+
+    #[actix_rt::test]
+    async fn test_expect() {
+        lazy(|cx| {
+            let mut buf = TestSeqBuffer::empty();
+            let cfg = ServiceConfig::new(KeepAlive::Disabled, 0, 0, false, None);
+
+            let services = HttpFlow::new(echo_payload_service(), ExpectHandler, None);
+
+            let h1 = Dispatcher::<_, _, _, _, UpgradeHandler>::new(
+                buf.clone(),
+                cfg,
+                services,
+                OnConnectData::default(),
+                None,
+            );
+
+            buf.extend_read_buf(
+                "\
+                POST /upload HTTP/1.1\r\n\
+                Content-Length: 5\r\n\
+                Expect: 100-continue\r\n\
+                \r\n\
+                ",
+            );
+
+            actix_rt::pin!(h1);
+
+            assert!(h1.as_mut().poll(cx).is_pending());
+            assert!(matches!(&h1.inner, DispatcherState::Normal(_)));
+
+            // polls: manual
+            assert_eq!(h1.poll_count, 1);
+            eprintln!("poll count: {}", h1.poll_count);
+
+            if let DispatcherState::Normal(ref inner) = h1.inner {
+                let io = inner.io.as_ref().unwrap();
+                let res = &io.write_buf()[..];
+                assert_eq!(
+                    str::from_utf8(res).unwrap(),
+                    "HTTP/1.1 100 Continue\r\n\r\n"
+                );
+            }
+
+            buf.extend_read_buf("12345");
+            assert!(h1.as_mut().poll(cx).is_ready());
+
+            // polls: manual manual shutdown
+            assert_eq!(h1.poll_count, 3);
+
+            if let DispatcherState::Normal(ref inner) = h1.inner {
+                let io = inner.io.as_ref().unwrap();
+                let mut res = (&io.write_buf()[..]).to_owned();
+                stabilize_date_header(&mut res);
+
+                assert_eq!(
+                    str::from_utf8(&res).unwrap(),
+                    "\
+                    HTTP/1.1 100 Continue\r\n\
+                    \r\n\
+                    HTTP/1.1 200 OK\r\n\
+                    content-length: 5\r\n\
+                    connection: close\r\n\
+                    date: Thu, 01 Jan 1970 12:34:56 UTC\r\n\
+                    \r\n\
+                    12345\
+                    "
+                );
+            }
+        })
+        .await;
+    }
+
+    #[actix_rt::test]
+    async fn test_eager_expect() {
+        lazy(|cx| {
+            let mut buf = TestSeqBuffer::empty();
+            let cfg = ServiceConfig::new(KeepAlive::Disabled, 0, 0, false, None);
+
+            let services = HttpFlow::new(echo_path_service(), ExpectHandler, None);
+
+            let h1 = Dispatcher::<_, _, _, _, UpgradeHandler>::new(
+                buf.clone(),
+                cfg,
+                services,
+                OnConnectData::default(),
+                None,
+            );
+
+            buf.extend_read_buf(
+                "\
+                POST /upload HTTP/1.1\r\n\
+                Content-Length: 5\r\n\
+                Expect: 100-continue\r\n\
+                \r\n\
+                ",
+            );
+
+            actix_rt::pin!(h1);
+
+            assert!(h1.as_mut().poll(cx).is_ready());
+            assert!(matches!(&h1.inner, DispatcherState::Normal(_)));
+
+            // polls: manual shutdown
+            assert_eq!(h1.poll_count, 2);
+
+            if let DispatcherState::Normal(ref inner) = h1.inner {
+                let io = inner.io.as_ref().unwrap();
+                let mut res = (&io.write_buf()[..]).to_owned();
+                stabilize_date_header(&mut res);
+
+                // Despite the content-length header and even though the request payload has not
+                // been sent, this test expects a complete service response since the payload
+                // is not used at all. The service passed to dispatcher is path echo and doesn't
+                // consume payload bytes.
+                assert_eq!(
+                    str::from_utf8(&res).unwrap(),
+                    "\
+                    HTTP/1.1 100 Continue\r\n\
+                    \r\n\
+                    HTTP/1.1 200 OK\r\n\
+                    content-length: 7\r\n\
+                    connection: close\r\n\
+                    date: Thu, 01 Jan 1970 12:34:56 UTC\r\n\
+                    \r\n\
+                    /upload\
+                    "
+                );
+            }
+        })
+        .await;
+    }
+
+    #[actix_rt::test]
+    async fn test_upgrade() {
+        lazy(|cx| {
+            let mut buf = TestSeqBuffer::empty();
+            let cfg = ServiceConfig::new(KeepAlive::Disabled, 0, 0, false, None);
+
+            let services =
+                HttpFlow::new(ok_service(), ExpectHandler, Some(UpgradeHandler));
+
+            let h1 = Dispatcher::<_, _, _, _, UpgradeHandler>::new(
+                buf.clone(),
+                cfg,
+                services,
+                OnConnectData::default(),
+                None,
+            );
+
+            buf.extend_read_buf(
+                "\
+                GET /ws HTTP/1.1\r\n\
+                Connection: Upgrade\r\n\
+                Upgrade: websocket\r\n\
+                \r\n\
+                ",
+            );
+
+            actix_rt::pin!(h1);
+
+            assert!(h1.as_mut().poll(cx).is_ready());
+            assert!(matches!(&h1.inner, DispatcherState::Upgrade(_)));
+
+            // polls: manual shutdown
+            assert_eq!(h1.poll_count, 2);
+        })
+        .await;
+    }
 }
diff --git a/actix-http/src/h1/encoder.rs b/actix-http/src/h1/encoder.rs
index e16b4c3dc..97916e7db 100644
--- a/actix-http/src/h1/encoder.rs
+++ b/actix-http/src/h1/encoder.rs
@@ -8,7 +8,7 @@ use bytes::{BufMut, BytesMut};
 
 use crate::body::BodySize;
 use crate::config::ServiceConfig;
-use crate::header::map;
+use crate::header::{map::Value, HeaderName};
 use crate::helpers;
 use crate::http::header::{CONNECTION, CONTENT_LENGTH, DATE, TRANSFER_ENCODING};
 use crate::http::{HeaderMap, StatusCode, Version};
@@ -21,7 +21,7 @@ const AVERAGE_HEADER_SIZE: usize = 30;
 pub(crate) struct MessageEncoder<T: MessageType> {
     pub length: BodySize,
     pub te: TransferEncoding,
-    _t: PhantomData<T>,
+    _phantom: PhantomData<T>,
 }
 
 impl<T: MessageType> Default for MessageEncoder<T> {
@@ -29,7 +29,7 @@ impl<T: MessageType> Default for MessageEncoder<T> {
         MessageEncoder {
             length: BodySize::None,
             te: TransferEncoding::empty(),
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
@@ -64,14 +64,17 @@ pub(crate) trait MessageType: Sized {
         // Content length
         if let Some(status) = self.status() {
             match status {
-                StatusCode::NO_CONTENT
-                | StatusCode::CONTINUE
-                | StatusCode::PROCESSING => length = BodySize::None,
-                StatusCode::SWITCHING_PROTOCOLS => {
+                StatusCode::CONTINUE
+                | StatusCode::SWITCHING_PROTOCOLS
+                | StatusCode::PROCESSING
+                | StatusCode::NO_CONTENT => {
+                    // skip content-length and transfer-encoding headers
+                    // See https://tools.ietf.org/html/rfc7230#section-3.3.1
+                    // and https://tools.ietf.org/html/rfc7230#section-3.3.2
                     skip_len = true;
-                    length = BodySize::Stream;
+                    length = BodySize::None
                 }
-                _ => (),
+                _ => {}
             }
         }
         match length {
@@ -115,24 +118,14 @@ pub(crate) trait MessageType: Sized {
                     dst.put_slice(b"connection: close\r\n")
                 }
             }
-            _ => (),
+            _ => {}
         }
 
-        // merging headers from head and extra headers. HeaderMap::new() does not allocate.
-        let empty_headers = HeaderMap::new();
-        let extra_headers = self.extra_headers().unwrap_or(&empty_headers);
-        let headers = self
-            .headers()
-            .inner
-            .iter()
-            .filter(|(name, _)| !extra_headers.contains_key(*name))
-            .chain(extra_headers.inner.iter());
-
         // write headers
 
         let mut has_date = false;
 
-        let mut buf = dst.bytes_mut().as_mut_ptr() as *mut u8;
+        let mut buf = dst.chunk_mut().as_mut_ptr();
         let mut remaining = dst.capacity() - dst.len();
 
         // tracks bytes written since last buffer resize
@@ -140,117 +133,67 @@ pub(crate) trait MessageType: Sized {
         // container's knowledge, this is used to sync the containers cursor after data is written
         let mut pos = 0;
 
-        for (key, value) in headers {
+        self.write_headers(|key, value| {
             match *key {
-                CONNECTION => continue,
-                TRANSFER_ENCODING | CONTENT_LENGTH if skip_len => continue,
+                CONNECTION => return,
+                TRANSFER_ENCODING | CONTENT_LENGTH if skip_len => return,
                 DATE => has_date = true,
-                _ => (),
+                _ => {}
             }
 
             let k = key.as_str().as_bytes();
             let k_len = k.len();
 
-            match value {
-                map::Value::One(ref val) => {
-                    let v = val.as_ref();
-                    let v_len = v.len();
+            // TODO: drain?
+            for val in value.iter() {
+                let v = val.as_ref();
+                let v_len = v.len();
 
-                    // key length + value length + colon + space + \r\n
-                    let len = k_len + v_len + 4;
+                // key length + value length + colon + space + \r\n
+                let len = k_len + v_len + 4;
 
-                    if len > remaining {
-                        // not enough room in buffer for this header; reserve more space
-
-                        // SAFETY: all the bytes written up to position "pos" are initialized
-                        // the written byte count and pointer advancement are kept in sync
-                        unsafe {
-                            dst.advance_mut(pos);
-                        }
-
-                        pos = 0;
-                        dst.reserve(len * 2);
-                        remaining = dst.capacity() - dst.len();
-
-                        // re-assign buf raw pointer since it's possible that the buffer was
-                        // reallocated and/or resized
-                        buf = dst.bytes_mut().as_mut_ptr() as *mut u8;
-                    }
-
-                    // SAFETY: on each write, it is enough to ensure that the advancement of the
-                    // cursor matches the number of bytes written
+                if len > remaining {
+                    // SAFETY: all the bytes written up to position "pos" are initialized
+                    // the written byte count and pointer advancement are kept in sync
                     unsafe {
-                        // use upper Camel-Case
-                        if camel_case {
-                            write_camel_case(k, from_raw_parts_mut(buf, k_len))
-                        } else {
-                            write_data(k, buf, k_len)
-                        }
-
-                        buf = buf.add(k_len);
-
-                        write_data(b": ", buf, 2);
-                        buf = buf.add(2);
-
-                        write_data(v, buf, v_len);
-                        buf = buf.add(v_len);
-
-                        write_data(b"\r\n", buf, 2);
-                        buf = buf.add(2);
+                        dst.advance_mut(pos);
                     }
 
-                    pos += len;
-                    remaining -= len;
+                    pos = 0;
+                    dst.reserve(len * 2);
+                    remaining = dst.capacity() - dst.len();
+
+                    // re-assign buf raw pointer since it's possible that the buffer was
+                    // reallocated and/or resized
+                    buf = dst.chunk_mut().as_mut_ptr();
                 }
 
-                map::Value::Multi(ref vec) => {
-                    for val in vec {
-                        let v = val.as_ref();
-                        let v_len = v.len();
-                        let len = k_len + v_len + 4;
-
-                        if len > remaining {
-                            // SAFETY: all the bytes written up to position "pos" are initialized
-                            // the written byte count and pointer advancement are kept in sync
-                            unsafe {
-                                dst.advance_mut(pos);
-                            }
-                            pos = 0;
-                            dst.reserve(len * 2);
-                            remaining = dst.capacity() - dst.len();
-
-                            // re-assign buf raw pointer since it's possible that the buffer was
-                            // reallocated and/or resized
-                            buf = dst.bytes_mut().as_mut_ptr() as *mut u8;
-                        }
-
-                        // SAFETY: on each write, it is enough to ensure that the advancement of
-                        // the cursor matches the number of bytes written
-                        unsafe {
-                            if camel_case {
-                                write_camel_case(k, from_raw_parts_mut(buf, k_len));
-                            } else {
-                                write_data(k, buf, k_len);
-                            }
-
-                            buf = buf.add(k_len);
-
-                            write_data(b": ", buf, 2);
-                            buf = buf.add(2);
-
-                            write_data(v, buf, v_len);
-                            buf = buf.add(v_len);
-
-                            write_data(b"\r\n", buf, 2);
-                            buf = buf.add(2);
-                        };
-
-                        pos += len;
-                        remaining -= len;
+                // SAFETY: on each write, it is enough to ensure that the advancement of
+                // the cursor matches the number of bytes written
+                unsafe {
+                    if camel_case {
+                        // use Camel-Case headers
+                        write_camel_case(k, from_raw_parts_mut(buf, k_len));
+                    } else {
+                        write_data(k, buf, k_len);
                     }
-                }
+
+                    buf = buf.add(k_len);
+
+                    write_data(b": ", buf, 2);
+                    buf = buf.add(2);
+
+                    write_data(v, buf, v_len);
+                    buf = buf.add(v_len);
+
+                    write_data(b"\r\n", buf, 2);
+                    buf = buf.add(2);
+                };
+
+                pos += len;
+                remaining -= len;
             }
-        }
+        });
 
         // final cursor synchronization with the bytes container
         //
@@ -270,6 +213,24 @@ pub(crate) trait MessageType: Sized {
 
         Ok(())
     }
+
+    fn write_headers<F>(&mut self, mut f: F)
+    where
+        F: FnMut(&HeaderName, &Value),
+    {
+        match self.extra_headers() {
+            Some(headers) => {
+                // merging headers from head and extra headers.
+                self.headers()
+                    .inner
+                    .iter()
+                    .filter(|(name, _)| !headers.contains_key(*name))
+                    .chain(headers.inner.iter())
+                    .for_each(|(k, v)| f(k, v))
+            }
+            None => self.headers().inner.iter().for_each(|(k, v)| f(k, v)),
+        }
+    }
 }
 
 impl MessageType for Response<()> {
@@ -326,7 +287,7 @@ impl MessageType for RequestHeadType {
         let head = self.as_ref();
         dst.reserve(256 + head.headers.len() * AVERAGE_HEADER_SIZE);
         write!(
-            Writer(dst),
+            helpers::Writer(dst),
             "{} {} {}",
             head.method,
             head.uri.path_and_query().map(|u| u.as_str()).unwrap_or("/"),
@@ -459,7 +420,7 @@ impl TransferEncoding {
                     *eof = true;
                     buf.extend_from_slice(b"0\r\n\r\n");
                 } else {
-                    writeln!(Writer(buf), "{:X}\r", msg.len())
+                    writeln!(helpers::Writer(buf), "{:X}\r", msg.len())
                         .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
 
                     buf.reserve(msg.len() + 2);
@@ -509,18 +470,6 @@ impl TransferEncoding {
     }
 }
 
-struct Writer<'a>(pub &'a mut BytesMut);
-
-impl<'a> io::Write for Writer<'a> {
-    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        self.0.extend_from_slice(buf);
-        Ok(buf.len())
-    }
-    fn flush(&mut self) -> io::Result<()> {
-        Ok(())
-    }
-}
-
 /// # Safety
 /// Callers must ensure that the given length matches given value length.
 unsafe fn write_data(value: &[u8], buf: *mut u8, len: usize) {
@@ -529,30 +478,29 @@ unsafe fn write_data(value: &[u8], buf: *mut u8, len: usize) {
 }
 
 fn write_camel_case(value: &[u8], buffer: &mut [u8]) {
-    let mut index = 0;
-    let key = value;
-    let mut key_iter = key.iter();
+    // first copy entire (potentially wrong) slice to output
+    buffer[..value.len()].copy_from_slice(value);
 
-    if let Some(c) = key_iter.next() {
-        if *c >= b'a' && *c <= b'z' {
-            buffer[index] = *c ^ b' ';
-            index += 1;
-        }
-    } else {
-        return;
+    let mut iter = value.iter();
+
+    // first character should be uppercase
+    if let Some(c @ b'a'..=b'z') = iter.next() {
+        buffer[0] = c & 0b1101_1111;
     }
 
-    while let Some(c) = key_iter.next() {
-        buffer[index] = *c;
-        index += 1;
-        if *c == b'-' {
-            if let Some(c) = key_iter.next() {
-                if *c >= b'a' && *c <= b'z' {
-                    buffer[index] = *c ^ b' ';
-                    index += 1;
-                }
+    // track 1 ahead of the current position since that's the location being assigned to
+    let mut index = 2;
+
+    // remaining characters after hyphens should also be uppercase
+    while let Some(&c) = iter.next() {
+        if c == b'-' {
+            // advance iter by one and uppercase if needed
+            if let Some(c @ b'a'..=b'z') = iter.next() {
+                buffer[index] = c & 0b1101_1111;
             }
         }
+
+        index += 1;
     }
 }
 
@@ -581,8 +529,8 @@ mod tests {
         );
     }
 
-    #[test]
-    fn test_camel_case() {
+    #[actix_rt::test]
+    async fn test_camel_case() {
         let mut bytes = BytesMut::with_capacity(2048);
         let mut head = RequestHead::default();
         head.set_camel_case_headers(true);
@@ -601,6 +549,7 @@ mod tests {
         );
         let data =
             String::from_utf8(Vec::from(bytes.split().freeze().as_ref())).unwrap();
+
         assert!(data.contains("Content-Length: 0\r\n"));
         assert!(data.contains("Connection: close\r\n"));
         assert!(data.contains("Content-Type: plain/text\r\n"));
@@ -643,8 +592,8 @@ mod tests {
         assert!(data.contains("date: date\r\n"));
     }
 
-    #[test]
-    fn test_extra_headers() {
+    #[actix_rt::test]
+    async fn test_extra_headers() {
         let mut bytes = BytesMut::with_capacity(2048);
 
         let mut head = RequestHead::default();
@@ -676,4 +625,28 @@ mod tests {
         assert!(data.contains("authorization: another authorization\r\n"));
         assert!(data.contains("date: date\r\n"));
     }
+
+    #[actix_rt::test]
+    async fn test_no_content_length() {
+        let mut bytes = BytesMut::with_capacity(2048);
+
+        let mut res: Response<()> =
+            Response::new(StatusCode::SWITCHING_PROTOCOLS).into_body::<()>();
+        res.headers_mut()
+            .insert(DATE, HeaderValue::from_static(&""));
+        res.headers_mut()
+            .insert(CONTENT_LENGTH, HeaderValue::from_static(&"0"));
+
+        let _ = res.encode_headers(
+            &mut bytes,
+            Version::HTTP_11,
+            BodySize::Stream,
+            ConnectionType::Upgrade,
+            &ServiceConfig::default(),
+        );
+        let data =
+            String::from_utf8(Vec::from(bytes.split().freeze().as_ref())).unwrap();
+        assert!(!data.contains("content-length: 0\r\n"));
+        assert!(!data.contains("transfer-encoding: chunked\r\n"));
+    }
 }
diff --git a/actix-http/src/h1/expect.rs b/actix-http/src/h1/expect.rs
index 6c08df08e..65856edf6 100644
--- a/actix-http/src/h1/expect.rs
+++ b/actix-http/src/h1/expect.rs
@@ -1,38 +1,36 @@
-use std::task::{Context, Poll};
+use std::task::Poll;
 
 use actix_service::{Service, ServiceFactory};
-use futures_util::future::{ok, Ready};
+use futures_util::future::{ready, Ready};
 
 use crate::error::Error;
 use crate::request::Request;
 
 pub struct ExpectHandler;
 
-impl ServiceFactory for ExpectHandler {
-    type Config = ();
-    type Request = Request;
+impl ServiceFactory<Request> for ExpectHandler {
     type Response = Request;
     type Error = Error;
+    type Config = ();
     type Service = ExpectHandler;
     type InitError = Error;
     type Future = Ready<Result<Self::Service, Self::InitError>>;
 
-    fn new_service(&self, _: ()) -> Self::Future {
-        ok(ExpectHandler)
+    fn new_service(&self, _: Self::Config) -> Self::Future {
+        ready(Ok(ExpectHandler))
     }
 }
 
-impl Service for ExpectHandler {
-    type Request = Request;
+impl Service<Request> for ExpectHandler {
     type Response = Request;
     type Error = Error;
     type Future = Ready<Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
+    actix_service::always_ready!();
 
-    fn call(&mut self, req: Request) -> Self::Future {
-        ok(req)
+    fn call(&self, req: Request) -> Self::Future {
+        ready(Ok(req))
+        // TODO: add some way to trigger error
+        // Err(error::ErrorExpectationFailed("test"))
     }
 }
diff --git a/actix-http/src/h1/mod.rs b/actix-http/src/h1/mod.rs
index 0c85f076a..7e6df6ceb 100644
--- a/actix-http/src/h1/mod.rs
+++ b/actix-http/src/h1/mod.rs
@@ -1,4 +1,4 @@
-//! HTTP/1 implementation
+//! HTTP/1 protocol implementation.
 use bytes::{Bytes, BytesMut};
 
 mod client;
@@ -17,7 +17,7 @@ pub use self::codec::Codec;
 pub use self::dispatcher::Dispatcher;
 pub use self::expect::ExpectHandler;
 pub use self::payload::Payload;
-pub use self::service::{H1Service, H1ServiceHandler, OneRequest};
+pub use self::service::{H1Service, H1ServiceHandler};
 pub use self::upgrade::UpgradeHandler;
 pub use self::utils::SendResponse;
 
diff --git a/actix-http/src/h1/payload.rs b/actix-http/src/h1/payload.rs
index 6a348810c..d4cfee146 100644
--- a/actix-http/src/h1/payload.rs
+++ b/actix-http/src/h1/payload.rs
@@ -182,9 +182,7 @@ impl Inner {
         self.len += data.len();
         self.items.push_back(data);
         self.need_read = self.len < MAX_BUFFER_SIZE;
-        if let Some(task) = self.task.take() {
-            task.wake()
-        }
+        self.task.wake();
     }
 
     #[cfg(test)]
diff --git a/actix-http/src/h1/service.rs b/actix-http/src/h1/service.rs
index 6aafd4089..b79453ebd 100644
--- a/actix-http/src/h1/service.rs
+++ b/actix-http/src/h1/service.rs
@@ -9,40 +9,40 @@ use actix_codec::{AsyncRead, AsyncWrite, Framed};
 use actix_rt::net::TcpStream;
 use actix_service::{pipeline_factory, IntoServiceFactory, Service, ServiceFactory};
 use futures_core::ready;
-use futures_util::future::{ok, Ready};
+use futures_util::future::ready;
 
 use crate::body::MessageBody;
-use crate::cloneable::CloneableService;
 use crate::config::ServiceConfig;
-use crate::error::{DispatchError, Error, ParseError};
-use crate::helpers::DataFactory;
+use crate::error::{DispatchError, Error};
 use crate::request::Request;
 use crate::response::Response;
+use crate::service::HttpFlow;
+use crate::{ConnectCallback, OnConnectData};
 
 use super::codec::Codec;
 use super::dispatcher::Dispatcher;
-use super::{ExpectHandler, Message, UpgradeHandler};
+use super::{ExpectHandler, UpgradeHandler};
 
 /// `ServiceFactory` implementation for HTTP1 transport
-pub struct H1Service<T, S, B, X = ExpectHandler, U = UpgradeHandler<T>> {
+pub struct H1Service<T, S, B, X = ExpectHandler, U = UpgradeHandler> {
     srv: S,
     cfg: ServiceConfig,
     expect: X,
     upgrade: Option<U>,
-    on_connect: Option<Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    _t: PhantomData<(T, B)>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
+    _phantom: PhantomData<B>,
 }
 
 impl<T, S, B> H1Service<T, S, B>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error>,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>>,
     B: MessageBody,
 {
     /// Create new `HttpService` instance with config.
-    pub(crate) fn with_config<F: IntoServiceFactory<S>>(
+    pub(crate) fn with_config<F: IntoServiceFactory<S, Request>>(
         cfg: ServiceConfig,
         service: F,
     ) -> Self {
@@ -51,27 +51,23 @@ where
             srv: service.into_factory(),
             expect: ExpectHandler,
             upgrade: None,
-            on_connect: None,
-            _t: PhantomData,
+            on_connect_ext: None,
+            _phantom: PhantomData,
         }
     }
 }
 
 impl<S, B, X, U> H1Service<TcpStream, S, B, X, U>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error>,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>>,
     B: MessageBody,
-    X: ServiceFactory<Config = (), Request = Request, Response = Request>,
+    X: ServiceFactory<Request, Config = (), Response = Request>,
     X::Error: Into<Error>,
     X::InitError: fmt::Debug,
-    U: ServiceFactory<
-        Config = (),
-        Request = (Request, Framed<TcpStream, Codec>),
-        Response = (),
-    >,
+    U: ServiceFactory<(Request, Framed<TcpStream, Codec>), Config = (), Response = ()>,
     U::Error: fmt::Display + Into<Error>,
     U::InitError: fmt::Debug,
 {
@@ -79,15 +75,15 @@ where
     pub fn tcp(
         self,
     ) -> impl ServiceFactory<
+        TcpStream,
         Config = (),
-        Request = TcpStream,
         Response = (),
         Error = DispatchError,
         InitError = (),
     > {
         pipeline_factory(|io: TcpStream| {
             let peer_addr = io.peer_addr().ok();
-            ok((io, peer_addr))
+            ready(Ok((io, peer_addr)))
         })
         .and_then(self)
     }
@@ -97,22 +93,23 @@ where
 mod openssl {
     use super::*;
 
-    use actix_tls::openssl::{Acceptor, SslAcceptor, SslStream};
-    use actix_tls::{openssl::HandshakeError, TlsError};
+    use actix_service::ServiceFactoryExt;
+    use actix_tls::accept::openssl::{Acceptor, SslAcceptor, SslError, SslStream};
+    use actix_tls::accept::TlsError;
 
     impl<S, B, X, U> H1Service<SslStream<TcpStream>, S, B, X, U>
     where
-        S: ServiceFactory<Config = (), Request = Request>,
+        S: ServiceFactory<Request, Config = ()>,
         S::Error: Into<Error>,
         S::InitError: fmt::Debug,
         S::Response: Into<Response<B>>,
         B: MessageBody,
-        X: ServiceFactory<Config = (), Request = Request, Response = Request>,
+        X: ServiceFactory<Request, Config = (), Response = Request>,
         X::Error: Into<Error>,
         X::InitError: fmt::Debug,
         U: ServiceFactory<
+            (Request, Framed<SslStream<TcpStream>, Codec>),
             Config = (),
-            Request = (Request, Framed<SslStream<TcpStream>, Codec>),
             Response = (),
         >,
         U::Error: fmt::Display + Into<Error>,
@@ -123,10 +120,10 @@ mod openssl {
             self,
             acceptor: SslAcceptor,
         ) -> impl ServiceFactory<
+            TcpStream,
             Config = (),
-            Request = TcpStream,
             Response = (),
-            Error = TlsError<HandshakeError<TcpStream>, DispatchError>,
+            Error = TlsError<SslError, DispatchError>,
             InitError = (),
         > {
             pipeline_factory(
@@ -136,7 +133,7 @@ mod openssl {
             )
             .and_then(|io: SslStream<TcpStream>| {
                 let peer_addr = io.get_ref().peer_addr().ok();
-                ok((io, peer_addr))
+                ready(Ok((io, peer_addr)))
             })
             .and_then(self.map_err(TlsError::Service))
         }
@@ -146,23 +143,24 @@ mod openssl {
 #[cfg(feature = "rustls")]
 mod rustls {
     use super::*;
-    use actix_tls::rustls::{Acceptor, ServerConfig, TlsStream};
-    use actix_tls::TlsError;
+    use actix_service::ServiceFactoryExt;
+    use actix_tls::accept::rustls::{Acceptor, ServerConfig, TlsStream};
+    use actix_tls::accept::TlsError;
     use std::{fmt, io};
 
     impl<S, B, X, U> H1Service<TlsStream<TcpStream>, S, B, X, U>
     where
-        S: ServiceFactory<Config = (), Request = Request>,
+        S: ServiceFactory<Request, Config = ()>,
         S::Error: Into<Error>,
         S::InitError: fmt::Debug,
         S::Response: Into<Response<B>>,
         B: MessageBody,
-        X: ServiceFactory<Config = (), Request = Request, Response = Request>,
+        X: ServiceFactory<Request, Config = (), Response = Request>,
         X::Error: Into<Error>,
         X::InitError: fmt::Debug,
         U: ServiceFactory<
+            (Request, Framed<TlsStream<TcpStream>, Codec>),
             Config = (),
-            Request = (Request, Framed<TlsStream<TcpStream>, Codec>),
             Response = (),
         >,
         U::Error: fmt::Display + Into<Error>,
@@ -173,8 +171,8 @@ mod rustls {
             self,
             config: ServerConfig,
         ) -> impl ServiceFactory<
+            TcpStream,
             Config = (),
-            Request = TcpStream,
             Response = (),
             Error = TlsError<io::Error, DispatchError>,
             InitError = (),
@@ -186,7 +184,7 @@ mod rustls {
             )
             .and_then(|io: TlsStream<TcpStream>| {
                 let peer_addr = io.get_ref().0.peer_addr().ok();
-                ok((io, peer_addr))
+                ready(Ok((io, peer_addr)))
             })
             .and_then(self.map_err(TlsError::Service))
         }
@@ -195,7 +193,7 @@ mod rustls {
 
 impl<T, S, B, X, U> H1Service<T, S, B, X, U>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error>,
     S::Response: Into<Response<B>>,
     S::InitError: fmt::Debug,
@@ -203,7 +201,7 @@ where
 {
     pub fn expect<X1>(self, expect: X1) -> H1Service<T, S, B, X1, U>
     where
-        X1: ServiceFactory<Request = Request, Response = Request>,
+        X1: ServiceFactory<Request, Response = Request>,
         X1::Error: Into<Error>,
         X1::InitError: fmt::Debug,
     {
@@ -212,14 +210,14 @@ where
             cfg: self.cfg,
             srv: self.srv,
             upgrade: self.upgrade,
-            on_connect: self.on_connect,
-            _t: PhantomData,
+            on_connect_ext: self.on_connect_ext,
+            _phantom: PhantomData,
         }
     }
 
     pub fn upgrade<U1>(self, upgrade: Option<U1>) -> H1Service<T, S, B, X, U1>
     where
-        U1: ServiceFactory<Request = (Request, Framed<T, Codec>), Response = ()>,
+        U1: ServiceFactory<(Request, Framed<T, Codec>), Response = ()>,
         U1::Error: fmt::Display,
         U1::InitError: fmt::Debug,
     {
@@ -228,42 +226,39 @@ where
             cfg: self.cfg,
             srv: self.srv,
             expect: self.expect,
-            on_connect: self.on_connect,
-            _t: PhantomData,
+            on_connect_ext: self.on_connect_ext,
+            _phantom: PhantomData,
         }
     }
 
     /// Set on connect callback.
-    pub(crate) fn on_connect(
-        mut self,
-        f: Option<Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    ) -> Self {
-        self.on_connect = f;
+    pub(crate) fn on_connect_ext(mut self, f: Option<Rc<ConnectCallback<T>>>) -> Self {
+        self.on_connect_ext = f;
         self
     }
 }
 
-impl<T, S, B, X, U> ServiceFactory for H1Service<T, S, B, X, U>
+impl<T, S, B, X, U> ServiceFactory<(T, Option<net::SocketAddr>)>
+    for H1Service<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error>,
     S::Response: Into<Response<B>>,
     S::InitError: fmt::Debug,
     B: MessageBody,
-    X: ServiceFactory<Config = (), Request = Request, Response = Request>,
+    X: ServiceFactory<Request, Config = (), Response = Request>,
     X::Error: Into<Error>,
     X::InitError: fmt::Debug,
-    U: ServiceFactory<Config = (), Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: ServiceFactory<(Request, Framed<T, Codec>), Config = (), Response = ()>,
     U::Error: fmt::Display + Into<Error>,
     U::InitError: fmt::Debug,
 {
-    type Config = ();
-    type Request = (T, Option<net::SocketAddr>);
     type Response = ();
     type Error = DispatchError;
-    type InitError = ();
+    type Config = ();
     type Service = H1ServiceHandler<T, S::Service, B, X::Service, U::Service>;
+    type InitError = ();
     type Future = H1ServiceResponse<T, S, B, X, U>;
 
     fn new_service(&self, _: ()) -> Self::Future {
@@ -273,9 +268,9 @@ where
             fut_upg: self.upgrade.as_ref().map(|f| f.new_service(())),
             expect: None,
             upgrade: None,
-            on_connect: self.on_connect.clone(),
+            on_connect_ext: self.on_connect_ext.clone(),
             cfg: Some(self.cfg.clone()),
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
@@ -284,13 +279,13 @@ where
 #[pin_project::pin_project]
 pub struct H1ServiceResponse<T, S, B, X, U>
 where
-    S: ServiceFactory<Request = Request>,
+    S: ServiceFactory<Request>,
     S::Error: Into<Error>,
     S::InitError: fmt::Debug,
-    X: ServiceFactory<Request = Request, Response = Request>,
+    X: ServiceFactory<Request, Response = Request>,
     X::Error: Into<Error>,
     X::InitError: fmt::Debug,
-    U: ServiceFactory<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: ServiceFactory<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display,
     U::InitError: fmt::Debug,
 {
@@ -302,23 +297,23 @@ where
     fut_upg: Option<U::Future>,
     expect: Option<X::Service>,
     upgrade: Option<U::Service>,
-    on_connect: Option<Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
     cfg: Option<ServiceConfig>,
-    _t: PhantomData<(T, B)>,
+    _phantom: PhantomData<B>,
 }
 
 impl<T, S, B, X, U> Future for H1ServiceResponse<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: ServiceFactory<Request = Request>,
+    S: ServiceFactory<Request>,
     S::Error: Into<Error>,
     S::Response: Into<Response<B>>,
     S::InitError: fmt::Debug,
     B: MessageBody,
-    X: ServiceFactory<Request = Request, Response = Request>,
+    X: ServiceFactory<Request, Response = Request>,
     X::Error: Into<Error>,
     X::InitError: fmt::Debug,
-    U: ServiceFactory<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: ServiceFactory<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display,
     U::InitError: fmt::Debug,
 {
@@ -342,7 +337,7 @@ where
                 .map_err(|e| log::error!("Init http service error: {:?}", e)))?;
             this = self.as_mut().project();
             *this.upgrade = Some(upgrade);
-            this.fut_ex.set(None);
+            this.fut_upg.set(None);
         }
 
         let result = ready!(this
@@ -352,75 +347,78 @@ where
 
         Poll::Ready(result.map(|service| {
             let this = self.as_mut().project();
+
             H1ServiceHandler::new(
                 this.cfg.take().unwrap(),
                 service,
                 this.expect.take().unwrap(),
                 this.upgrade.take(),
-                this.on_connect.clone(),
+                this.on_connect_ext.clone(),
             )
         }))
     }
 }
 
-/// `Service` implementation for HTTP1 transport
-pub struct H1ServiceHandler<T, S: Service, B, X: Service, U: Service> {
-    srv: CloneableService<S>,
-    expect: CloneableService<X>,
-    upgrade: Option<CloneableService<U>>,
-    on_connect: Option<Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
+/// `Service` implementation for HTTP/1 transport
+pub struct H1ServiceHandler<T, S, B, X, U>
+where
+    S: Service<Request>,
+    X: Service<Request>,
+    U: Service<(Request, Framed<T, Codec>)>,
+{
+    flow: Rc<HttpFlow<S, X, U>>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
     cfg: ServiceConfig,
-    _t: PhantomData<(T, B)>,
+    _phantom: PhantomData<B>,
 }
 
 impl<T, S, B, X, U> H1ServiceHandler<T, S, B, X, U>
 where
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error>,
     S::Response: Into<Response<B>>,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
     fn new(
         cfg: ServiceConfig,
-        srv: S,
+        service: S,
         expect: X,
         upgrade: Option<U>,
-        on_connect: Option<Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
+        on_connect_ext: Option<Rc<ConnectCallback<T>>>,
     ) -> H1ServiceHandler<T, S, B, X, U> {
         H1ServiceHandler {
-            srv: CloneableService::new(srv),
-            expect: CloneableService::new(expect),
-            upgrade: upgrade.map(CloneableService::new),
+            flow: HttpFlow::new(service, expect, upgrade),
             cfg,
-            on_connect,
-            _t: PhantomData,
+            on_connect_ext,
+            _phantom: PhantomData,
         }
     }
 }
 
-impl<T, S, B, X, U> Service for H1ServiceHandler<T, S, B, X, U>
+impl<T, S, B, X, U> Service<(T, Option<net::SocketAddr>)>
+    for H1ServiceHandler<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error>,
     S::Response: Into<Response<B>>,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, Codec>), Response = ()>,
     U::Error: fmt::Display + Into<Error>,
 {
-    type Request = (T, Option<net::SocketAddr>);
     type Response = ();
     type Error = DispatchError;
     type Future = Dispatcher<T, S, B, X, U>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         let ready = self
+            .flow
             .expect
             .poll_ready(cx)
             .map_err(|e| {
@@ -431,7 +429,8 @@ where
             .is_ready();
 
         let ready = self
-            .srv
+            .flow
+            .service
             .poll_ready(cx)
             .map_err(|e| {
                 let e = e.into();
@@ -441,7 +440,7 @@ where
             .is_ready()
             && ready;
 
-        let ready = if let Some(ref mut upg) = self.upgrade {
+        let ready = if let Some(ref upg) = self.flow.upgrade {
             upg.poll_ready(cx)
                 .map_err(|e| {
                     let e = e.into();
@@ -461,121 +460,16 @@ where
         }
     }
 
-    fn call(&mut self, (io, addr): Self::Request) -> Self::Future {
-        let on_connect = if let Some(ref on_connect) = self.on_connect {
-            Some(on_connect(&io))
-        } else {
-            None
-        };
+    fn call(&self, (io, addr): (T, Option<net::SocketAddr>)) -> Self::Future {
+        let on_connect_data =
+            OnConnectData::from_io(&io, self.on_connect_ext.as_deref());
 
         Dispatcher::new(
             io,
             self.cfg.clone(),
-            self.srv.clone(),
-            self.expect.clone(),
-            self.upgrade.clone(),
-            on_connect,
+            self.flow.clone(),
+            on_connect_data,
             addr,
         )
     }
 }
-
-/// `ServiceFactory` implementation for `OneRequestService` service
-#[derive(Default)]
-pub struct OneRequest<T> {
-    config: ServiceConfig,
-    _t: PhantomData<T>,
-}
-
-impl<T> OneRequest<T>
-where
-    T: AsyncRead + AsyncWrite + Unpin,
-{
-    /// Create new `H1SimpleService` instance.
-    pub fn new() -> Self {
-        OneRequest {
-            config: ServiceConfig::default(),
-            _t: PhantomData,
-        }
-    }
-}
-
-impl<T> ServiceFactory for OneRequest<T>
-where
-    T: AsyncRead + AsyncWrite + Unpin,
-{
-    type Config = ();
-    type Request = T;
-    type Response = (Request, Framed<T, Codec>);
-    type Error = ParseError;
-    type InitError = ();
-    type Service = OneRequestService<T>;
-    type Future = Ready<Result<Self::Service, Self::InitError>>;
-
-    fn new_service(&self, _: ()) -> Self::Future {
-        ok(OneRequestService {
-            _t: PhantomData,
-            config: self.config.clone(),
-        })
-    }
-}
-
-/// `Service` implementation for HTTP1 transport. Reads one request and returns
-/// request and framed object.
-pub struct OneRequestService<T> {
-    _t: PhantomData<T>,
-    config: ServiceConfig,
-}
-
-impl<T> Service for OneRequestService<T>
-where
-    T: AsyncRead + AsyncWrite + Unpin,
-{
-    type Request = T;
-    type Response = (Request, Framed<T, Codec>);
-    type Error = ParseError;
-    type Future = OneRequestServiceResponse<T>;
-
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
-
-    fn call(&mut self, req: Self::Request) -> Self::Future {
-        OneRequestServiceResponse {
-            framed: Some(Framed::new(req, Codec::new(self.config.clone()))),
-        }
-    }
-}
-
-#[doc(hidden)]
-#[pin_project::pin_project]
-pub struct OneRequestServiceResponse<T>
-where
-    T: AsyncRead + AsyncWrite + Unpin,
-{
-    #[pin]
-    framed: Option<Framed<T, Codec>>,
-}
-
-impl<T> Future for OneRequestServiceResponse<T>
-where
-    T: AsyncRead + AsyncWrite + Unpin,
-{
-    type Output = Result<(Request, Framed<T, Codec>), ParseError>;
-
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.as_mut().project();
-
-        match ready!(this.framed.as_pin_mut().unwrap().next_item(cx)) {
-            Some(Ok(req)) => match req {
-                Message::Item(req) => {
-                    let mut this = self.as_mut().project();
-                    Poll::Ready(Ok((req, this.framed.take().unwrap())))
-                }
-                Message::Chunk(_) => unreachable!("Something is wrong"),
-            },
-            Some(Err(err)) => Poll::Ready(Err(err)),
-            None => Poll::Ready(Err(ParseError::Incomplete)),
-        }
-    }
-}
diff --git a/actix-http/src/h1/upgrade.rs b/actix-http/src/h1/upgrade.rs
index 22ba99e26..5e24d84e3 100644
--- a/actix-http/src/h1/upgrade.rs
+++ b/actix-http/src/h1/upgrade.rs
@@ -1,22 +1,20 @@
-use std::marker::PhantomData;
-use std::task::{Context, Poll};
+use std::task::Poll;
 
 use actix_codec::Framed;
 use actix_service::{Service, ServiceFactory};
-use futures_util::future::Ready;
+use futures_util::future::{ready, Ready};
 
 use crate::error::Error;
 use crate::h1::Codec;
 use crate::request::Request;
 
-pub struct UpgradeHandler<T>(PhantomData<T>);
+pub struct UpgradeHandler;
 
-impl<T> ServiceFactory for UpgradeHandler<T> {
-    type Config = ();
-    type Request = (Request, Framed<T, Codec>);
+impl<T> ServiceFactory<(Request, Framed<T, Codec>)> for UpgradeHandler {
     type Response = ();
     type Error = Error;
-    type Service = UpgradeHandler<T>;
+    type Config = ();
+    type Service = UpgradeHandler;
     type InitError = Error;
     type Future = Ready<Result<Self::Service, Self::InitError>>;
 
@@ -25,17 +23,14 @@ impl<T> ServiceFactory for UpgradeHandler<T> {
     }
 }
 
-impl<T> Service for UpgradeHandler<T> {
-    type Request = (Request, Framed<T, Codec>);
+impl<T> Service<(Request, Framed<T, Codec>)> for UpgradeHandler {
     type Response = ();
     type Error = Error;
     type Future = Ready<Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
+    actix_service::always_ready!();
 
-    fn call(&mut self, _: Self::Request) -> Self::Future {
-        unimplemented!()
+    fn call(&self, _: (Request, Framed<T, Codec>)) -> Self::Future {
+        ready(Ok(()))
     }
 }
diff --git a/actix-http/src/h2/dispatcher.rs b/actix-http/src/h2/dispatcher.rs
index daa651f4d..5ccd2a9d1 100644
--- a/actix-http/src/h2/dispatcher.rs
+++ b/actix-http/src/h2/dispatcher.rs
@@ -1,63 +1,65 @@
-use std::convert::TryFrom;
 use std::future::Future;
 use std::marker::PhantomData;
 use std::net;
 use std::pin::Pin;
+use std::rc::Rc;
 use std::task::{Context, Poll};
+use std::{cmp, convert::TryFrom};
 
 use actix_codec::{AsyncRead, AsyncWrite};
-use actix_rt::time::{Delay, Instant};
+use actix_rt::time::{Instant, Sleep};
 use actix_service::Service;
 use bytes::{Bytes, BytesMut};
+use futures_core::ready;
 use h2::server::{Connection, SendResponse};
 use h2::SendStream;
 use http::header::{HeaderValue, CONNECTION, CONTENT_LENGTH, DATE, TRANSFER_ENCODING};
 use log::{error, trace};
 
 use crate::body::{BodySize, MessageBody, ResponseBody};
-use crate::cloneable::CloneableService;
 use crate::config::ServiceConfig;
 use crate::error::{DispatchError, Error};
-use crate::helpers::DataFactory;
-use crate::httpmessage::HttpMessage;
 use crate::message::ResponseHead;
 use crate::payload::Payload;
 use crate::request::Request;
 use crate::response::Response;
+use crate::service::HttpFlow;
+use crate::OnConnectData;
 
 const CHUNK_SIZE: usize = 16_384;
 
-/// Dispatcher for HTTP/2 protocol
+/// Dispatcher for HTTP/2 protocol.
 #[pin_project::pin_project]
-pub struct Dispatcher<T, S: Service<Request = Request>, B: MessageBody>
+pub struct Dispatcher<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
+    S: Service<Request>,
+    B: MessageBody,
 {
-    service: CloneableService<S>,
+    flow: Rc<HttpFlow<S, X, U>>,
     connection: Connection<T, Bytes>,
-    on_connect: Option<Box<dyn DataFactory>>,
+    on_connect_data: OnConnectData,
     config: ServiceConfig,
     peer_addr: Option<net::SocketAddr>,
     ka_expire: Instant,
-    ka_timer: Option<Delay>,
-    _t: PhantomData<B>,
+    ka_timer: Option<Sleep>,
+    _phantom: PhantomData<B>,
 }
 
-impl<T, S, B> Dispatcher<T, S, B>
+impl<T, S, B, X, U> Dispatcher<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error>,
-    // S::Future: 'static,
     S::Response: Into<Response<B>>,
     B: MessageBody,
 {
     pub(crate) fn new(
-        service: CloneableService<S>,
+        flow: Rc<HttpFlow<S, X, U>>,
         connection: Connection<T, Bytes>,
-        on_connect: Option<Box<dyn DataFactory>>,
+        on_connect_data: OnConnectData,
         config: ServiceConfig,
-        timeout: Option<Delay>,
+        timeout: Option<Sleep>,
         peer_addr: Option<net::SocketAddr>,
     ) -> Self {
         // let keepalive = config.keep_alive_enabled();
@@ -77,22 +79,22 @@ where
         };
 
         Dispatcher {
-            service,
+            flow,
             config,
             peer_addr,
             connection,
-            on_connect,
+            on_connect_data,
             ka_expire,
             ka_timer,
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
 
-impl<T, S, B> Future for Dispatcher<T, S, B>
+impl<T, S, B, X, U> Future for Dispatcher<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error> + 'static,
     S::Future: 'static,
     S::Response: Into<Response<B>> + 'static,
@@ -105,10 +107,12 @@ where
         let this = self.get_mut();
 
         loop {
-            match Pin::new(&mut this.connection).poll_accept(cx) {
-                Poll::Ready(None) => return Poll::Ready(Ok(())),
-                Poll::Ready(Some(Err(err))) => return Poll::Ready(Err(err.into())),
-                Poll::Ready(Some(Ok((req, res)))) => {
+            match ready!(Pin::new(&mut this.connection).poll_accept(cx)) {
+                None => return Poll::Ready(Ok(())),
+
+                Some(Err(err)) => return Poll::Ready(Err(err.into())),
+
+                Some(Ok((req, res))) => {
                     // update keep-alive expire
                     if this.ka_timer.is_some() {
                         if let Some(expire) = this.config.keep_alive_expire() {
@@ -117,11 +121,9 @@ where
                     }
 
                     let (parts, body) = req.into_parts();
-                    let mut req = Request::with_payload(Payload::<
-                        crate::payload::PayloadStream,
-                    >::H2(
-                        crate::h2::Payload::new(body)
-                    ));
+                    let pl = crate::h2::Payload::new(body);
+                    let pl = Payload::<crate::payload::PayloadStream>::H2(pl);
+                    let mut req = Request::with_payload(pl);
 
                     let head = &mut req.head_mut();
                     head.uri = parts.uri;
@@ -130,27 +132,21 @@ where
                     head.headers = parts.headers.into();
                     head.peer_addr = this.peer_addr;
 
-                    // set on_connect data
-                    if let Some(ref on_connect) = this.on_connect {
-                        on_connect.set(&mut req.extensions_mut());
-                    }
+                    // merge on_connect_ext data into request extensions
+                    this.on_connect_data.merge_into(&mut req);
 
-                    actix_rt::spawn(ServiceResponse::<
-                        S::Future,
-                        S::Response,
-                        S::Error,
-                        B,
-                    > {
+                    let svc = ServiceResponse::<S::Future, S::Response, S::Error, B> {
                         state: ServiceResponseState::ServiceCall(
-                            this.service.call(req),
+                            this.flow.service.call(req),
                             Some(res),
                         ),
                         config: this.config.clone(),
                         buffer: None,
-                        _t: PhantomData,
-                    });
+                        _phantom: PhantomData,
+                    };
+
+                    actix_rt::spawn(svc);
                 }
-                Poll::Pending => return Poll::Pending,
             }
         }
     }
@@ -162,7 +158,7 @@ struct ServiceResponse<F, I, E, B> {
     state: ServiceResponseState<F, B>,
     config: ServiceConfig,
     buffer: Option<Bytes>,
-    _t: PhantomData<(I, E)>,
+    _phantom: PhantomData<(I, E)>,
 }
 
 #[pin_project::pin_project(project = ServiceResponseStateProj)]
@@ -199,8 +195,9 @@ where
                 skip_len = true;
                 *size = BodySize::Stream;
             }
-            _ => (),
+            _ => {}
         }
+
         let _ = match size {
             BodySize::None | BodySize::Stream => None,
             BodySize::Empty => res
@@ -215,11 +212,13 @@ where
         // copy headers
         for (key, value) in head.headers.iter() {
             match *key {
-                CONNECTION | TRANSFER_ENCODING => continue, // http2 specific
+                // omit HTTP/1 only headers
+                CONNECTION | TRANSFER_ENCODING => continue,
                 CONTENT_LENGTH if skip_len => continue,
                 DATE => has_date = true,
-                _ => (),
+                _ => {}
             }
+
             res.headers_mut().append(key, value.clone());
         }
 
@@ -251,109 +250,117 @@ where
         let mut this = self.as_mut().project();
 
         match this.state.project() {
-            ServiceResponseStateProj::ServiceCall(call, send) => match call.poll(cx) {
-                Poll::Ready(Ok(res)) => {
-                    let (res, body) = res.into().replace_body(());
+            ServiceResponseStateProj::ServiceCall(call, send) => {
+                match ready!(call.poll(cx)) {
+                    Ok(res) => {
+                        let (res, body) = res.into().replace_body(());
 
-                    let mut send = send.take().unwrap();
-                    let mut size = body.size();
-                    let h2_res = self.as_mut().prepare_response(res.head(), &mut size);
-                    this = self.as_mut().project();
+                        let mut send = send.take().unwrap();
+                        let mut size = body.size();
+                        let h2_res =
+                            self.as_mut().prepare_response(res.head(), &mut size);
+                        this = self.as_mut().project();
 
-                    let stream = match send.send_response(h2_res, size.is_eof()) {
-                        Err(e) => {
-                            trace!("Error sending h2 response: {:?}", e);
-                            return Poll::Ready(());
+                        let stream = match send.send_response(h2_res, size.is_eof()) {
+                            Err(e) => {
+                                trace!("Error sending HTTP/2 response: {:?}", e);
+                                return Poll::Ready(());
+                            }
+                            Ok(stream) => stream,
+                        };
+
+                        if size.is_eof() {
+                            Poll::Ready(())
+                        } else {
+                            this.state
+                                .set(ServiceResponseState::SendPayload(stream, body));
+                            self.poll(cx)
                         }
-                        Ok(stream) => stream,
-                    };
+                    }
 
-                    if size.is_eof() {
-                        Poll::Ready(())
-                    } else {
-                        this.state
-                            .set(ServiceResponseState::SendPayload(stream, body));
-                        self.poll(cx)
+                    Err(e) => {
+                        let res: Response = e.into().into();
+                        let (res, body) = res.replace_body(());
+
+                        let mut send = send.take().unwrap();
+                        let mut size = body.size();
+                        let h2_res =
+                            self.as_mut().prepare_response(res.head(), &mut size);
+                        this = self.as_mut().project();
+
+                        let stream = match send.send_response(h2_res, size.is_eof()) {
+                            Err(e) => {
+                                trace!("Error sending HTTP/2 response: {:?}", e);
+                                return Poll::Ready(());
+                            }
+                            Ok(stream) => stream,
+                        };
+
+                        if size.is_eof() {
+                            Poll::Ready(())
+                        } else {
+                            this.state.set(ServiceResponseState::SendPayload(
+                                stream,
+                                body.into_body(),
+                            ));
+                            self.poll(cx)
+                        }
                     }
                 }
-                Poll::Pending => Poll::Pending,
-                Poll::Ready(Err(e)) => {
-                    let res: Response = e.into().into();
-                    let (res, body) = res.replace_body(());
+            }
 
-                    let mut send = send.take().unwrap();
-                    let mut size = body.size();
-                    let h2_res = self.as_mut().prepare_response(res.head(), &mut size);
-                    this = self.as_mut().project();
-
-                    let stream = match send.send_response(h2_res, size.is_eof()) {
-                        Err(e) => {
-                            trace!("Error sending h2 response: {:?}", e);
-                            return Poll::Ready(());
-                        }
-                        Ok(stream) => stream,
-                    };
-
-                    if size.is_eof() {
-                        Poll::Ready(())
-                    } else {
-                        this.state.set(ServiceResponseState::SendPayload(
-                            stream,
-                            body.into_body(),
-                        ));
-                        self.poll(cx)
-                    }
-                }
-            },
             ServiceResponseStateProj::SendPayload(ref mut stream, ref mut body) => {
                 loop {
                     loop {
-                        if let Some(ref mut buffer) = this.buffer {
-                            match stream.poll_capacity(cx) {
-                                Poll::Pending => return Poll::Pending,
-                                Poll::Ready(None) => return Poll::Ready(()),
-                                Poll::Ready(Some(Ok(cap))) => {
-                                    let len = buffer.len();
-                                    let bytes = buffer.split_to(std::cmp::min(cap, len));
+                        match this.buffer {
+                            Some(ref mut buffer) => {
+                                match ready!(stream.poll_capacity(cx)) {
+                                    None => return Poll::Ready(()),
 
-                                    if let Err(e) = stream.send_data(bytes, false) {
+                                    Some(Ok(cap)) => {
+                                        let len = buffer.len();
+                                        let bytes = buffer.split_to(cmp::min(cap, len));
+
+                                        if let Err(e) = stream.send_data(bytes, false) {
+                                            warn!("{:?}", e);
+                                            return Poll::Ready(());
+                                        } else if !buffer.is_empty() {
+                                            let cap = cmp::min(buffer.len(), CHUNK_SIZE);
+                                            stream.reserve_capacity(cap);
+                                        } else {
+                                            this.buffer.take();
+                                        }
+                                    }
+
+                                    Some(Err(e)) => {
                                         warn!("{:?}", e);
                                         return Poll::Ready(());
-                                    } else if !buffer.is_empty() {
-                                        let cap =
-                                            std::cmp::min(buffer.len(), CHUNK_SIZE);
-                                        stream.reserve_capacity(cap);
-                                    } else {
-                                        this.buffer.take();
                                     }
                                 }
-                                Poll::Ready(Some(Err(e))) => {
-                                    warn!("{:?}", e);
-                                    return Poll::Ready(());
-                                }
                             }
-                        } else {
-                            match body.as_mut().poll_next(cx) {
-                                Poll::Pending => return Poll::Pending,
-                                Poll::Ready(None) => {
+
+                            None => match ready!(body.as_mut().poll_next(cx)) {
+                                None => {
                                     if let Err(e) = stream.send_data(Bytes::new(), true)
                                     {
                                         warn!("{:?}", e);
                                     }
                                     return Poll::Ready(());
                                 }
-                                Poll::Ready(Some(Ok(chunk))) => {
-                                    stream.reserve_capacity(std::cmp::min(
+
+                                Some(Ok(chunk)) => {
+                                    stream.reserve_capacity(cmp::min(
                                         chunk.len(),
                                         CHUNK_SIZE,
                                     ));
                                     *this.buffer = Some(chunk);
                                 }
-                                Poll::Ready(Some(Err(e))) => {
+
+                                Some(Err(e)) => {
                                     error!("Response payload stream error: {:?}", e);
                                     return Poll::Ready(());
                                 }
-                            }
+                            },
                         }
                     }
                 }
diff --git a/actix-http/src/h2/mod.rs b/actix-http/src/h2/mod.rs
index b00969227..7eff44ac1 100644
--- a/actix-http/src/h2/mod.rs
+++ b/actix-http/src/h2/mod.rs
@@ -1,9 +1,12 @@
-//! HTTP/2 implementation
-use std::pin::Pin;
-use std::task::{Context, Poll};
+//! HTTP/2 protocol.
+
+use std::{
+    pin::Pin,
+    task::{Context, Poll},
+};
 
 use bytes::Bytes;
-use futures_core::Stream;
+use futures_core::{ready, Stream};
 use h2::RecvStream;
 
 mod dispatcher;
@@ -13,14 +16,14 @@ pub use self::dispatcher::Dispatcher;
 pub use self::service::H2Service;
 use crate::error::PayloadError;
 
-/// H2 receive stream
+/// HTTP/2 peer stream.
 pub struct Payload {
-    pl: RecvStream,
+    stream: RecvStream,
 }
 
 impl Payload {
-    pub(crate) fn new(pl: RecvStream) -> Self {
-        Self { pl }
+    pub(crate) fn new(stream: RecvStream) -> Self {
+        Self { stream }
     }
 }
 
@@ -33,18 +36,17 @@ impl Stream for Payload {
     ) -> Poll<Option<Self::Item>> {
         let this = self.get_mut();
 
-        match Pin::new(&mut this.pl).poll_data(cx) {
-            Poll::Ready(Some(Ok(chunk))) => {
+        match ready!(Pin::new(&mut this.stream).poll_data(cx)) {
+            Some(Ok(chunk)) => {
                 let len = chunk.len();
-                if let Err(err) = this.pl.flow_control().release_capacity(len) {
-                    Poll::Ready(Some(Err(err.into())))
-                } else {
-                    Poll::Ready(Some(Ok(chunk)))
+
+                match this.stream.flow_control().release_capacity(len) {
+                    Ok(()) => Poll::Ready(Some(Ok(chunk))),
+                    Err(err) => Poll::Ready(Some(Err(err.into()))),
                 }
             }
-            Poll::Ready(Some(Err(err))) => Poll::Ready(Some(Err(err.into()))),
-            Poll::Pending => Poll::Pending,
-            Poll::Ready(None) => Poll::Ready(None),
+            Some(Err(err)) => Poll::Ready(Some(Err(err.into()))),
+            None => Poll::Ready(None),
         }
     }
 }
diff --git a/actix-http/src/h2/service.rs b/actix-http/src/h2/service.rs
index 6b5620e02..e00c8d968 100644
--- a/actix-http/src/h2/service.rs
+++ b/actix-http/src/h2/service.rs
@@ -2,7 +2,7 @@ use std::future::Future;
 use std::marker::PhantomData;
 use std::pin::Pin;
 use std::task::{Context, Poll};
-use std::{net, rc};
+use std::{net, rc::Rc};
 
 use actix_codec::{AsyncRead, AsyncWrite};
 use actix_rt::net::TcpStream;
@@ -17,68 +17,65 @@ use h2::server::{self, Handshake};
 use log::error;
 
 use crate::body::MessageBody;
-use crate::cloneable::CloneableService;
 use crate::config::ServiceConfig;
 use crate::error::{DispatchError, Error};
-use crate::helpers::DataFactory;
 use crate::request::Request;
 use crate::response::Response;
+use crate::service::HttpFlow;
+use crate::{ConnectCallback, OnConnectData};
 
 use super::dispatcher::Dispatcher;
 
-/// `ServiceFactory` implementation for HTTP2 transport
+/// `ServiceFactory` implementation for HTTP/2 transport
 pub struct H2Service<T, S, B> {
     srv: S,
     cfg: ServiceConfig,
-    on_connect: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    _t: PhantomData<(T, B)>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
+    _phantom: PhantomData<(T, B)>,
 }
 
 impl<T, S, B> H2Service<T, S, B>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
 {
-    /// Create new `HttpService` instance with config.
-    pub(crate) fn with_config<F: IntoServiceFactory<S>>(
+    /// Create new `H2Service` instance with config.
+    pub(crate) fn with_config<F: IntoServiceFactory<S, Request>>(
         cfg: ServiceConfig,
         service: F,
     ) -> Self {
         H2Service {
             cfg,
-            on_connect: None,
+            on_connect_ext: None,
             srv: service.into_factory(),
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 
     /// Set on connect callback.
-    pub(crate) fn on_connect(
-        mut self,
-        f: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    ) -> Self {
-        self.on_connect = f;
+    pub(crate) fn on_connect_ext(mut self, f: Option<Rc<ConnectCallback<T>>>) -> Self {
+        self.on_connect_ext = f;
         self
     }
 }
 
 impl<S, B> H2Service<TcpStream, S, B>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
 {
-    /// Create simple tcp based service
+    /// Create plain TCP based service
     pub fn tcp(
         self,
     ) -> impl ServiceFactory<
+        TcpStream,
         Config = (),
-        Request = TcpStream,
         Response = (),
         Error = DispatchError,
         InitError = S::InitError,
@@ -95,29 +92,29 @@ where
 
 #[cfg(feature = "openssl")]
 mod openssl {
-    use actix_service::{fn_factory, fn_service};
-    use actix_tls::openssl::{Acceptor, SslAcceptor, SslStream};
-    use actix_tls::{openssl::HandshakeError, TlsError};
+    use actix_service::{fn_factory, fn_service, ServiceFactoryExt};
+    use actix_tls::accept::openssl::{Acceptor, SslAcceptor, SslError, SslStream};
+    use actix_tls::accept::TlsError;
 
     use super::*;
 
     impl<S, B> H2Service<SslStream<TcpStream>, S, B>
     where
-        S: ServiceFactory<Config = (), Request = Request>,
+        S: ServiceFactory<Request, Config = ()>,
         S::Error: Into<Error> + 'static,
         S::Response: Into<Response<B>> + 'static,
-        <S::Service as Service>::Future: 'static,
+        <S::Service as Service<Request>>::Future: 'static,
         B: MessageBody + 'static,
     {
-        /// Create ssl based service
+        /// Create OpenSSL based service
         pub fn openssl(
             self,
             acceptor: SslAcceptor,
         ) -> impl ServiceFactory<
+            TcpStream,
             Config = (),
-            Request = TcpStream,
             Response = (),
-            Error = TlsError<HandshakeError<TcpStream>, DispatchError>,
+            Error = TlsError<SslError, DispatchError>,
             InitError = S::InitError,
         > {
             pipeline_factory(
@@ -139,25 +136,26 @@ mod openssl {
 #[cfg(feature = "rustls")]
 mod rustls {
     use super::*;
-    use actix_tls::rustls::{Acceptor, ServerConfig, TlsStream};
-    use actix_tls::TlsError;
+    use actix_service::ServiceFactoryExt;
+    use actix_tls::accept::rustls::{Acceptor, ServerConfig, TlsStream};
+    use actix_tls::accept::TlsError;
     use std::io;
 
     impl<S, B> H2Service<TlsStream<TcpStream>, S, B>
     where
-        S: ServiceFactory<Config = (), Request = Request>,
+        S: ServiceFactory<Request, Config = ()>,
         S::Error: Into<Error> + 'static,
         S::Response: Into<Response<B>> + 'static,
-        <S::Service as Service>::Future: 'static,
+        <S::Service as Service<Request>>::Future: 'static,
         B: MessageBody + 'static,
     {
-        /// Create openssl based service
+        /// Create Rustls based service
         pub fn rustls(
             self,
             mut config: ServerConfig,
         ) -> impl ServiceFactory<
+            TcpStream,
             Config = (),
-            Request = TcpStream,
             Response = (),
             Error = TlsError<io::Error, DispatchError>,
             InitError = S::InitError,
@@ -181,50 +179,52 @@ mod rustls {
     }
 }
 
-impl<T, S, B> ServiceFactory for H2Service<T, S, B>
+impl<T, S, B> ServiceFactory<(T, Option<net::SocketAddr>)> for H2Service<T, S, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
 {
-    type Config = ();
-    type Request = (T, Option<net::SocketAddr>);
     type Response = ();
     type Error = DispatchError;
-    type InitError = S::InitError;
+    type Config = ();
     type Service = H2ServiceHandler<T, S::Service, B>;
+    type InitError = S::InitError;
     type Future = H2ServiceResponse<T, S, B>;
 
     fn new_service(&self, _: ()) -> Self::Future {
         H2ServiceResponse {
             fut: self.srv.new_service(()),
             cfg: Some(self.cfg.clone()),
-            on_connect: self.on_connect.clone(),
-            _t: PhantomData,
+            on_connect_ext: self.on_connect_ext.clone(),
+            _phantom: PhantomData,
         }
     }
 }
 
 #[doc(hidden)]
 #[pin_project::pin_project]
-pub struct H2ServiceResponse<T, S: ServiceFactory, B> {
+pub struct H2ServiceResponse<T, S, B>
+where
+    S: ServiceFactory<Request>,
+{
     #[pin]
     fut: S::Future,
     cfg: Option<ServiceConfig>,
-    on_connect: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    _t: PhantomData<(T, B)>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
+    _phantom: PhantomData<B>,
 }
 
 impl<T, S, B> Future for H2ServiceResponse<T, S, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
 {
     type Output = Result<H2ServiceHandler<T, S::Service, B>, S::InitError>;
@@ -232,28 +232,31 @@ where
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let this = self.as_mut().project();
 
-        Poll::Ready(ready!(this.fut.poll(cx)).map(|service| {
+        this.fut.poll(cx).map_ok(|service| {
             let this = self.as_mut().project();
             H2ServiceHandler::new(
                 this.cfg.take().unwrap(),
-                this.on_connect.clone(),
+                this.on_connect_ext.clone(),
                 service,
             )
-        }))
+        })
     }
 }
 
-/// `Service` implementation for http/2 transport
-pub struct H2ServiceHandler<T, S: Service, B> {
-    srv: CloneableService<S>,
+/// `Service` implementation for HTTP/2 transport
+pub struct H2ServiceHandler<T, S, B>
+where
+    S: Service<Request>,
+{
+    flow: Rc<HttpFlow<S, (), ()>>,
     cfg: ServiceConfig,
-    on_connect: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    _t: PhantomData<(T, B)>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
+    _phantom: PhantomData<B>,
 }
 
 impl<T, S, B> H2ServiceHandler<T, S, B>
 where
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error> + 'static,
     S::Future: 'static,
     S::Response: Into<Response<B>> + 'static,
@@ -261,70 +264,66 @@ where
 {
     fn new(
         cfg: ServiceConfig,
-        on_connect: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-        srv: S,
+        on_connect_ext: Option<Rc<ConnectCallback<T>>>,
+        service: S,
     ) -> H2ServiceHandler<T, S, B> {
         H2ServiceHandler {
+            flow: HttpFlow::new(service, (), None),
             cfg,
-            on_connect,
-            srv: CloneableService::new(srv),
-            _t: PhantomData,
+            on_connect_ext,
+            _phantom: PhantomData,
         }
     }
 }
 
-impl<T, S, B> Service for H2ServiceHandler<T, S, B>
+impl<T, S, B> Service<(T, Option<net::SocketAddr>)> for H2ServiceHandler<T, S, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error> + 'static,
     S::Future: 'static,
     S::Response: Into<Response<B>> + 'static,
     B: MessageBody + 'static,
 {
-    type Request = (T, Option<net::SocketAddr>);
     type Response = ();
     type Error = DispatchError;
     type Future = H2ServiceHandlerResponse<T, S, B>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.srv.poll_ready(cx).map_err(|e| {
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        self.flow.service.poll_ready(cx).map_err(|e| {
             let e = e.into();
             error!("Service readiness error: {:?}", e);
             DispatchError::Service(e)
         })
     }
 
-    fn call(&mut self, (io, addr): Self::Request) -> Self::Future {
-        let on_connect = if let Some(ref on_connect) = self.on_connect {
-            Some(on_connect(&io))
-        } else {
-            None
-        };
+    fn call(&self, (io, addr): (T, Option<net::SocketAddr>)) -> Self::Future {
+        let on_connect_data =
+            OnConnectData::from_io(&io, self.on_connect_ext.as_deref());
 
         H2ServiceHandlerResponse {
             state: State::Handshake(
-                Some(self.srv.clone()),
+                Some(self.flow.clone()),
                 Some(self.cfg.clone()),
                 addr,
-                on_connect,
+                on_connect_data,
                 server::handshake(io),
             ),
         }
     }
 }
 
-enum State<T, S: Service<Request = Request>, B: MessageBody>
+enum State<T, S: Service<Request>, B: MessageBody>
 where
     T: AsyncRead + AsyncWrite + Unpin,
     S::Future: 'static,
 {
-    Incoming(Dispatcher<T, S, B>),
+    Incoming(Dispatcher<T, S, B, (), ()>),
     Handshake(
-        Option<CloneableService<S>>,
+        Option<Rc<HttpFlow<S, (), ()>>>,
         Option<ServiceConfig>,
         Option<net::SocketAddr>,
-        Option<Box<dyn DataFactory>>,
+        OnConnectData,
         Handshake<T, Bytes>,
     ),
 }
@@ -332,7 +331,7 @@ where
 pub struct H2ServiceHandlerResponse<T, S, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error> + 'static,
     S::Future: 'static,
     S::Response: Into<Response<B>> + 'static,
@@ -344,7 +343,7 @@ where
 impl<T, S, B> Future for H2ServiceHandlerResponse<T, S, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error> + 'static,
     S::Future: 'static,
     S::Response: Into<Response<B>> + 'static,
@@ -359,25 +358,25 @@ where
                 ref mut srv,
                 ref mut config,
                 ref peer_addr,
-                ref mut on_connect,
+                ref mut on_connect_data,
                 ref mut handshake,
-            ) => match Pin::new(handshake).poll(cx) {
-                Poll::Ready(Ok(conn)) => {
+            ) => match ready!(Pin::new(handshake).poll(cx)) {
+                Ok(conn) => {
+                    let on_connect_data = std::mem::take(on_connect_data);
                     self.state = State::Incoming(Dispatcher::new(
                         srv.take().unwrap(),
                         conn,
-                        on_connect.take(),
+                        on_connect_data,
                         config.take().unwrap(),
                         None,
                         *peer_addr,
                     ));
                     self.poll(cx)
                 }
-                Poll::Ready(Err(err)) => {
+                Err(err) => {
                     trace!("H2 handshake error: {}", err);
                     Poll::Ready(Err(err.into()))
                 }
-                Poll::Pending => Poll::Pending,
             },
         }
     }
diff --git a/actix-http/src/header/as_name.rs b/actix-http/src/header/as_name.rs
new file mode 100644
index 000000000..af81ff7f2
--- /dev/null
+++ b/actix-http/src/header/as_name.rs
@@ -0,0 +1,48 @@
+//! Helper trait for types that can be effectively borrowed as a [HeaderValue].
+//!
+//! [HeaderValue]: crate::http::HeaderValue
+
+use std::{borrow::Cow, str::FromStr};
+
+use http::header::{HeaderName, InvalidHeaderName};
+
+pub trait AsHeaderName: Sealed {}
+
+pub trait Sealed {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName>;
+}
+
+impl Sealed for HeaderName {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        Ok(Cow::Borrowed(self))
+    }
+}
+impl AsHeaderName for HeaderName {}
+
+impl Sealed for &HeaderName {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        Ok(Cow::Borrowed(*self))
+    }
+}
+impl AsHeaderName for &HeaderName {}
+
+impl Sealed for &str {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        HeaderName::from_str(self).map(Cow::Owned)
+    }
+}
+impl AsHeaderName for &str {}
+
+impl Sealed for String {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        HeaderName::from_str(self).map(Cow::Owned)
+    }
+}
+impl AsHeaderName for String {}
+
+impl Sealed for &String {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        HeaderName::from_str(self).map(Cow::Owned)
+    }
+}
+impl AsHeaderName for &String {}
diff --git a/actix-http/src/header/common/accept.rs b/actix-http/src/header/common/accept.rs
index d52eba241..775da3394 100644
--- a/actix-http/src/header/common/accept.rs
+++ b/actix-http/src/header/common/accept.rs
@@ -1,3 +1,5 @@
+use std::cmp::Ordering;
+
 use mime::Mime;
 
 use crate::header::{qitem, QualityItem};
@@ -7,7 +9,7 @@ header! {
     /// `Accept` header, defined in [RFC7231](http://tools.ietf.org/html/rfc7231#section-5.3.2)
     ///
     /// The `Accept` header field can be used by user agents to specify
-    /// response media types that are acceptable.  Accept header fields can
+    /// response media types that are acceptable. Accept header fields can
     /// be used to indicate that the request is specifically limited to a
     /// small set of desired types, as in the case of a request for an
     /// in-line image
@@ -30,50 +32,36 @@ header! {
     /// * `text/plain; q=0.5, text/html, text/x-dvi; q=0.8, text/x-c`
     ///
     /// # Examples
-    /// ```rust
-    /// # extern crate actix_http;
-    /// extern crate mime;
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{Accept, qitem};
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    ///
-    /// builder.set(
+    /// builder.insert_header(
     ///     Accept(vec![
     ///         qitem(mime::TEXT_HTML),
     ///     ])
     /// );
-    /// # }
     /// ```
     ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// extern crate mime;
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{Accept, qitem};
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    ///
-    /// builder.set(
+    /// builder.insert_header(
     ///     Accept(vec![
     ///         qitem(mime::APPLICATION_JSON),
     ///     ])
     /// );
-    /// # }
     /// ```
     ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// extern crate mime;
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{Accept, QualityItem, q, qitem};
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    ///
-    /// builder.set(
+    /// builder.insert_header(
     ///     Accept(vec![
     ///         qitem(mime::TEXT_HTML),
     ///         qitem("application/xhtml+xml".parse().unwrap()),
@@ -88,7 +76,6 @@ header! {
     ///         ),
     ///     ])
     /// );
-    /// # }
     /// ```
     (Accept, header::ACCEPT) => (QualityItem<Mime>)+
 
@@ -97,14 +84,14 @@ header! {
          test_header!(
             test1,
             vec![b"audio/*; q=0.2, audio/basic"],
-            Some(HeaderField(vec![
+            Some(Accept(vec![
                 QualityItem::new("audio/*".parse().unwrap(), q(200)),
                 qitem("audio/basic".parse().unwrap()),
                 ])));
         test_header!(
             test2,
             vec![b"text/plain; q=0.5, text/html, text/x-dvi; q=0.8, text/x-c"],
-            Some(HeaderField(vec![
+            Some(Accept(vec![
                 QualityItem::new(mime::TEXT_PLAIN, q(500)),
                 qitem(mime::TEXT_HTML),
                 QualityItem::new(
@@ -130,7 +117,7 @@ header! {
         #[test]
         fn test_fuzzing1() {
             use crate::test::TestRequest;
-            let req = TestRequest::with_header(crate::header::ACCEPT, "chunk#;e").finish();
+            let req = TestRequest::default().insert_header((crate::header::ACCEPT, "chunk#;e")).finish();
             let header = Accept::parse(&req);
             assert!(header.is_ok());
         }
@@ -138,23 +125,148 @@ header! {
 }
 
 impl Accept {
-    /// A constructor to easily create `Accept: */*`.
+    /// Construct `Accept: */*`.
     pub fn star() -> Accept {
         Accept(vec![qitem(mime::STAR_STAR)])
     }
 
-    /// A constructor to easily create `Accept: application/json`.
+    /// Construct `Accept: application/json`.
     pub fn json() -> Accept {
         Accept(vec![qitem(mime::APPLICATION_JSON)])
     }
 
-    /// A constructor to easily create `Accept: text/*`.
+    /// Construct `Accept: text/*`.
     pub fn text() -> Accept {
         Accept(vec![qitem(mime::TEXT_STAR)])
     }
 
-    /// A constructor to easily create `Accept: image/*`.
+    /// Construct `Accept: image/*`.
     pub fn image() -> Accept {
         Accept(vec![qitem(mime::IMAGE_STAR)])
     }
+
+    /// Construct `Accept: text/html`.
+    pub fn html() -> Accept {
+        Accept(vec![qitem(mime::TEXT_HTML)])
+    }
+
+    /// Returns a sorted list of mime types from highest to lowest preference, accounting for
+    /// [q-factor weighting] and specificity.
+    ///
+    /// [q-factor weighting]: https://tools.ietf.org/html/rfc7231#section-5.3.2
+    pub fn mime_precedence(&self) -> Vec<Mime> {
+        let mut types = self.0.clone();
+
+        // use stable sort so items with equal q-factor and specificity retain listed order
+        types.sort_by(|a, b| {
+            // sort by q-factor descending
+            b.quality.cmp(&a.quality).then_with(|| {
+                // use specificity rules on mime types with
+                // same q-factor (eg. text/html > text/* > */*)
+
+                // subtypes are not comparable if main type is star, so return
+                match (a.item.type_(), b.item.type_()) {
+                    (mime::STAR, mime::STAR) => return Ordering::Equal,
+
+                    // a is sorted after b
+                    (mime::STAR, _) => return Ordering::Greater,
+
+                    // a is sorted before b
+                    (_, mime::STAR) => return Ordering::Less,
+
+                    _ => {}
+                }
+
+                // in both these match expressions, the returned ordering appears
+                // inverted because sort is high-to-low ("descending") precedence
+                match (a.item.subtype(), b.item.subtype()) {
+                    (mime::STAR, mime::STAR) => Ordering::Equal,
+
+                    // a is sorted after b
+                    (mime::STAR, _) => Ordering::Greater,
+
+                    // a is sorted before b
+                    (_, mime::STAR) => Ordering::Less,
+
+                    _ => Ordering::Equal,
+                }
+            })
+        });
+
+        types.into_iter().map(|qitem| qitem.item).collect()
+    }
+
+    /// Extracts the most preferable mime type, accounting for [q-factor weighting].
+    ///
+    /// If no q-factors are provided, the first mime type is chosen. Note that items without
+    /// q-factors are given the maximum preference value.
+    ///
+    /// Returns `None` if contained list is empty.
+    ///
+    /// [q-factor weighting]: https://tools.ietf.org/html/rfc7231#section-5.3.2
+    pub fn mime_preference(&self) -> Option<Mime> {
+        let types = self.mime_precedence();
+        types.first().cloned()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::header::q;
+
+    #[test]
+    fn test_mime_precedence() {
+        let test = Accept(vec![]);
+        assert!(test.mime_precedence().is_empty());
+
+        let test = Accept(vec![qitem(mime::APPLICATION_JSON)]);
+        assert_eq!(test.mime_precedence(), vec!(mime::APPLICATION_JSON));
+
+        let test = Accept(vec![
+            qitem(mime::TEXT_HTML),
+            "application/xhtml+xml".parse().unwrap(),
+            QualityItem::new("application/xml".parse().unwrap(), q(0.9)),
+            QualityItem::new(mime::STAR_STAR, q(0.8)),
+        ]);
+        assert_eq!(
+            test.mime_precedence(),
+            vec![
+                mime::TEXT_HTML,
+                "application/xhtml+xml".parse().unwrap(),
+                "application/xml".parse().unwrap(),
+                mime::STAR_STAR,
+            ]
+        );
+
+        let test = Accept(vec![
+            qitem(mime::STAR_STAR),
+            qitem(mime::IMAGE_STAR),
+            qitem(mime::IMAGE_PNG),
+        ]);
+        assert_eq!(
+            test.mime_precedence(),
+            vec![mime::IMAGE_PNG, mime::IMAGE_STAR, mime::STAR_STAR]
+        );
+    }
+
+    #[test]
+    fn test_mime_preference() {
+        let test = Accept(vec![
+            qitem(mime::TEXT_HTML),
+            "application/xhtml+xml".parse().unwrap(),
+            QualityItem::new("application/xml".parse().unwrap(), q(0.9)),
+            QualityItem::new(mime::STAR_STAR, q(0.8)),
+        ]);
+        assert_eq!(test.mime_preference(), Some(mime::TEXT_HTML));
+
+        let test = Accept(vec![
+            QualityItem::new("video/*".parse().unwrap(), q(0.8)),
+            qitem(mime::IMAGE_PNG),
+            QualityItem::new(mime::STAR_STAR, q(0.5)),
+            qitem(mime::IMAGE_SVG),
+            QualityItem::new(mime::IMAGE_STAR, q(0.8)),
+        ]);
+        assert_eq!(test.mime_preference(), Some(mime::IMAGE_PNG));
+    }
 }
diff --git a/actix-http/src/header/common/accept_charset.rs b/actix-http/src/header/common/accept_charset.rs
index 291ca53b6..db530a8bc 100644
--- a/actix-http/src/header/common/accept_charset.rs
+++ b/actix-http/src/header/common/accept_charset.rs
@@ -21,44 +21,37 @@ header! {
     /// * `iso-8859-5, unicode-1-1;q=0.8`
     ///
     /// # Examples
-    /// ```rust
-    /// # extern crate actix_http;
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{AcceptCharset, Charset, qitem};
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     AcceptCharset(vec![qitem(Charset::Us_Ascii)])
     /// );
-    /// # }
     /// ```
-    /// ```rust
-    /// # extern crate actix_http;
+    ///
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{AcceptCharset, Charset, q, QualityItem};
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     AcceptCharset(vec![
     ///         QualityItem::new(Charset::Us_Ascii, q(900)),
     ///         QualityItem::new(Charset::Iso_8859_10, q(200)),
     ///     ])
     /// );
-    /// # }
     /// ```
-    /// ```rust
-    /// # extern crate actix_http;
+    ///
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{AcceptCharset, Charset, qitem};
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     AcceptCharset(vec![qitem(Charset::Ext("utf-8".to_owned()))])
     /// );
-    /// # }
     /// ```
     (AcceptCharset, ACCEPT_CHARSET) => (QualityItem<Charset>)+
 
diff --git a/actix-http/src/header/common/accept_language.rs b/actix-http/src/header/common/accept_language.rs
index 55879b57f..a7ad00863 100644
--- a/actix-http/src/header/common/accept_language.rs
+++ b/actix-http/src/header/common/accept_language.rs
@@ -22,41 +22,35 @@ header! {
     ///
     /// # Examples
     ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// # extern crate language_tags;
+    /// ```
+    /// use language_tags::langtag;
     /// use actix_http::Response;
     /// use actix_http::http::header::{AcceptLanguage, LanguageTag, qitem};
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
     /// let mut langtag: LanguageTag = Default::default();
     /// langtag.language = Some("en".to_owned());
     /// langtag.region = Some("US".to_owned());
-    /// builder.set(
+    /// builder.insert_header(
     ///     AcceptLanguage(vec![
     ///         qitem(langtag),
     ///     ])
     /// );
-    /// # }
     /// ```
     ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// # #[macro_use] extern crate language_tags;
+    /// ```
+    /// use language_tags::langtag;
     /// use actix_http::Response;
     /// use actix_http::http::header::{AcceptLanguage, QualityItem, q, qitem};
-    /// #
-    /// # fn main() {
+    ///
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     AcceptLanguage(vec![
     ///         qitem(langtag!(da)),
     ///         QualityItem::new(langtag!(en;;;GB), q(800)),
     ///         QualityItem::new(langtag!(en), q(700)),
     ///     ])
     /// );
-    /// # }
     /// ```
     (AcceptLanguage, ACCEPT_LANGUAGE) => (QualityItem<LanguageTag>)+
 
diff --git a/actix-http/src/header/common/allow.rs b/actix-http/src/header/common/allow.rs
index 88c21763c..06b1efedc 100644
--- a/actix-http/src/header/common/allow.rs
+++ b/actix-http/src/header/common/allow.rs
@@ -22,38 +22,28 @@ header! {
     ///
     /// # Examples
     ///
-    /// ```rust
-    /// # extern crate http;
-    /// # extern crate actix_http;
+    /// ```
     /// use actix_http::Response;
-    /// use actix_http::http::header::Allow;
-    /// use http::Method;
+    /// use actix_http::http::{header::Allow, Method};
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     Allow(vec![Method::GET])
     /// );
-    /// # }
     /// ```
     ///
-    /// ```rust
-    /// # extern crate http;
-    /// # extern crate actix_http;
+    /// ```
     /// use actix_http::Response;
-    /// use actix_http::http::header::Allow;
-    /// use http::Method;
+    /// use actix_http::http::{header::Allow, Method};
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     Allow(vec![
     ///         Method::GET,
     ///         Method::POST,
     ///         Method::PATCH,
     ///     ])
     /// );
-    /// # }
     /// ```
     (Allow, header::ALLOW) => (Method)*
 
diff --git a/actix-http/src/header/common/cache_control.rs b/actix-http/src/header/common/cache_control.rs
index ec94ce4a9..94ce9a750 100644
--- a/actix-http/src/header/common/cache_control.rs
+++ b/actix-http/src/header/common/cache_control.rs
@@ -28,12 +28,12 @@ use crate::header::{
 /// * `max-age=30`
 ///
 /// # Examples
-/// ```rust
+/// ```
 /// use actix_http::Response;
 /// use actix_http::http::header::{CacheControl, CacheDirective};
 ///
 /// let mut builder = Response::Ok();
-/// builder.set(CacheControl(vec![CacheDirective::MaxAge(86400u32)]));
+/// builder.insert_header(CacheControl(vec![CacheDirective::MaxAge(86400u32)]));
 /// ```
 ///
 /// ```rust
@@ -41,7 +41,7 @@ use crate::header::{
 /// use actix_http::http::header::{CacheControl, CacheDirective};
 ///
 /// let mut builder = Response::Ok();
-/// builder.set(CacheControl(vec![
+/// builder.insert_header(CacheControl(vec![
 ///     CacheDirective::NoCache,
 ///     CacheDirective::Private,
 ///     CacheDirective::MaxAge(360u32),
@@ -82,7 +82,7 @@ impl fmt::Display for CacheControl {
 impl IntoHeaderValue for CacheControl {
     type Error = header::InvalidHeaderValue;
 
-    fn try_into(self) -> Result<header::HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<header::HeaderValue, Self::Error> {
         let mut writer = Writer::new();
         let _ = write!(&mut writer, "{}", self);
         header::HeaderValue::from_maybe_shared(writer.take())
@@ -196,7 +196,8 @@ mod tests {
 
     #[test]
     fn test_parse_multiple_headers() {
-        let req = TestRequest::with_header(header::CACHE_CONTROL, "no-cache, private")
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "no-cache, private"))
             .finish();
         let cache = Header::parse(&req);
         assert_eq!(
@@ -210,9 +211,9 @@ mod tests {
 
     #[test]
     fn test_parse_argument() {
-        let req =
-            TestRequest::with_header(header::CACHE_CONTROL, "max-age=100, private")
-                .finish();
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "max-age=100, private"))
+            .finish();
         let cache = Header::parse(&req);
         assert_eq!(
             cache.ok(),
@@ -225,8 +226,9 @@ mod tests {
 
     #[test]
     fn test_parse_quote_form() {
-        let req =
-            TestRequest::with_header(header::CACHE_CONTROL, "max-age=\"200\"").finish();
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "max-age=\"200\""))
+            .finish();
         let cache = Header::parse(&req);
         assert_eq!(
             cache.ok(),
@@ -236,8 +238,9 @@ mod tests {
 
     #[test]
     fn test_parse_extension() {
-        let req =
-            TestRequest::with_header(header::CACHE_CONTROL, "foo, bar=baz").finish();
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "foo, bar=baz"))
+            .finish();
         let cache = Header::parse(&req);
         assert_eq!(
             cache.ok(),
@@ -250,7 +253,9 @@ mod tests {
 
     #[test]
     fn test_parse_bad_syntax() {
-        let req = TestRequest::with_header(header::CACHE_CONTROL, "foo=").finish();
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "foo="))
+            .finish();
         let cache: Result<CacheControl, _> = Header::parse(&req);
         assert_eq!(cache.ok(), None)
     }
diff --git a/actix-http/src/header/common/content_disposition.rs b/actix-http/src/header/common/content_disposition.rs
index 37da830ca..ecc59aba3 100644
--- a/actix-http/src/header/common/content_disposition.rs
+++ b/actix-http/src/header/common/content_disposition.rs
@@ -1,10 +1,10 @@
-// # References
-//
-// "The Content-Disposition Header Field" https://www.ietf.org/rfc/rfc2183.txt
-// "The Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)" https://www.ietf.org/rfc/rfc6266.txt
-// "Returning Values from Forms: multipart/form-data" https://www.ietf.org/rfc/rfc7578.txt
-// Browser conformance tests at: http://greenbytes.de/tech/tc2231/
-// IANA assignment: http://www.iana.org/assignments/cont-disp/cont-disp.xhtml
+//! # References
+//!
+//! "The Content-Disposition Header Field" https://www.ietf.org/rfc/rfc2183.txt
+//! "The Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)" https://www.ietf.org/rfc/rfc6266.txt
+//! "Returning Values from Forms: multipart/form-data" https://www.ietf.org/rfc/rfc7578.txt
+//! Browser conformance tests at: http://greenbytes.de/tech/tc2231/
+//! IANA assignment: http://www.iana.org/assignments/cont-disp/cont-disp.xhtml
 
 use lazy_static::lazy_static;
 use regex::Regex;
@@ -318,9 +318,8 @@ impl ContentDisposition {
                 return Err(crate::error::ParseError::Header);
             }
             left = new_left;
-            if param_name.ends_with('*') {
+            if let Some(param_name) = param_name.strip_suffix('*') {
                 // extended parameters
-                let param_name = &param_name[..param_name.len() - 1]; // trim asterisk
                 let (ext_value, new_left) = split_once_and_trim(left, ';');
                 left = new_left;
                 let ext_value = header::parse_extended_value(ext_value)?;
@@ -455,7 +454,7 @@ impl ContentDisposition {
 impl IntoHeaderValue for ContentDisposition {
     type Error = header::InvalidHeaderValue;
 
-    fn try_into(self) -> Result<header::HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<header::HeaderValue, Self::Error> {
         let mut writer = Writer::new();
         let _ = write!(&mut writer, "{}", self);
         header::HeaderValue::from_maybe_shared(writer.take())
@@ -550,8 +549,7 @@ impl fmt::Display for ContentDisposition {
         write!(f, "{}", self.disposition)?;
         self.parameters
             .iter()
-            .map(|param| write!(f, "; {}", param))
-            .collect()
+            .try_for_each(|param| write!(f, "; {}", param))
     }
 }
 
diff --git a/actix-http/src/header/common/content_encoding.rs b/actix-http/src/header/common/content_encoding.rs
new file mode 100644
index 000000000..b93d66101
--- /dev/null
+++ b/actix-http/src/header/common/content_encoding.rs
@@ -0,0 +1,106 @@
+use std::{convert::Infallible, str::FromStr};
+
+use http::header::InvalidHeaderValue;
+
+use crate::{
+    error::ParseError,
+    header::{self, from_one_raw_str, Header, HeaderName, HeaderValue, IntoHeaderValue},
+    HttpMessage,
+};
+
+/// Represents a supported content encoding.
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum ContentEncoding {
+    /// Automatically select encoding based on encoding negotiation.
+    Auto,
+
+    /// A format using the Brotli algorithm.
+    Br,
+
+    /// A format using the zlib structure with deflate algorithm.
+    Deflate,
+
+    /// Gzip algorithm.
+    Gzip,
+
+    /// Indicates the identity function (i.e. no compression, nor modification).
+    Identity,
+}
+
+impl ContentEncoding {
+    /// Is the content compressed?
+    #[inline]
+    pub fn is_compression(self) -> bool {
+        matches!(self, ContentEncoding::Identity | ContentEncoding::Auto)
+    }
+
+    /// Convert content encoding to string
+    #[inline]
+    pub fn as_str(self) -> &'static str {
+        match self {
+            ContentEncoding::Br => "br",
+            ContentEncoding::Gzip => "gzip",
+            ContentEncoding::Deflate => "deflate",
+            ContentEncoding::Identity | ContentEncoding::Auto => "identity",
+        }
+    }
+
+    /// Default Q-factor (quality) value.
+    #[inline]
+    pub fn quality(self) -> f64 {
+        match self {
+            ContentEncoding::Br => 1.1,
+            ContentEncoding::Gzip => 1.0,
+            ContentEncoding::Deflate => 0.9,
+            ContentEncoding::Identity | ContentEncoding::Auto => 0.1,
+        }
+    }
+}
+
+impl Default for ContentEncoding {
+    fn default() -> Self {
+        Self::Identity
+    }
+}
+
+impl FromStr for ContentEncoding {
+    type Err = Infallible;
+
+    fn from_str(val: &str) -> Result<Self, Self::Err> {
+        Ok(Self::from(val))
+    }
+}
+
+impl From<&str> for ContentEncoding {
+    fn from(val: &str) -> ContentEncoding {
+        let val = val.trim();
+
+        if val.eq_ignore_ascii_case("br") {
+            ContentEncoding::Br
+        } else if val.eq_ignore_ascii_case("gzip") {
+            ContentEncoding::Gzip
+        } else if val.eq_ignore_ascii_case("deflate") {
+            ContentEncoding::Deflate
+        } else {
+            ContentEncoding::default()
+        }
+    }
+}
+
+impl IntoHeaderValue for ContentEncoding {
+    type Error = InvalidHeaderValue;
+
+    fn try_into_value(self) -> Result<http::HeaderValue, Self::Error> {
+        Ok(HeaderValue::from_static(self.as_str()))
+    }
+}
+
+impl Header for ContentEncoding {
+    fn name() -> HeaderName {
+        header::CONTENT_ENCODING
+    }
+
+    fn parse<T: HttpMessage>(msg: &T) -> Result<Self, ParseError> {
+        from_one_raw_str(msg.headers().get(Self::name()))
+    }
+}
diff --git a/actix-http/src/header/common/content_language.rs b/actix-http/src/header/common/content_language.rs
index 838981a39..e9be67a1b 100644
--- a/actix-http/src/header/common/content_language.rs
+++ b/actix-http/src/header/common/content_language.rs
@@ -23,38 +23,31 @@ header! {
     ///
     /// # Examples
     ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// # #[macro_use] extern crate language_tags;
+    /// ```
+    /// use language_tags::langtag;
     /// use actix_http::Response;
-    /// # use actix_http::http::header::{ContentLanguage, qitem};
-    /// #
-    /// # fn main() {
+    /// use actix_http::http::header::{ContentLanguage, qitem};
+    ///
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     ContentLanguage(vec![
     ///         qitem(langtag!(en)),
     ///     ])
     /// );
-    /// # }
     /// ```
     ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// # #[macro_use] extern crate language_tags;
+    /// ```
+    /// use language_tags::langtag;
     /// use actix_http::Response;
-    /// # use actix_http::http::header::{ContentLanguage, qitem};
-    /// #
-    /// # fn main() {
+    /// use actix_http::http::header::{ContentLanguage, qitem};
     ///
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     ContentLanguage(vec![
     ///         qitem(langtag!(da)),
     ///         qitem(langtag!(en;;;GB)),
     ///     ])
     /// );
-    /// # }
     /// ```
     (ContentLanguage, CONTENT_LANGUAGE) => (QualityItem<LanguageTag>)+
 
diff --git a/actix-http/src/header/common/content_range.rs b/actix-http/src/header/common/content_range.rs
index 9a604c641..8b7552377 100644
--- a/actix-http/src/header/common/content_range.rs
+++ b/actix-http/src/header/common/content_range.rs
@@ -200,7 +200,7 @@ impl Display for ContentRangeSpec {
 impl IntoHeaderValue for ContentRangeSpec {
     type Error = InvalidHeaderValue;
 
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
         let mut writer = Writer::new();
         let _ = write!(&mut writer, "{}", self);
         HeaderValue::from_maybe_shared(writer.take())
diff --git a/actix-http/src/header/common/content_type.rs b/actix-http/src/header/common/content_type.rs
index a0baa5637..ac5c7e5b8 100644
--- a/actix-http/src/header/common/content_type.rs
+++ b/actix-http/src/header/common/content_type.rs
@@ -30,31 +30,24 @@ header! {
     ///
     /// # Examples
     ///
-    /// ```rust
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::ContentType;
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     ContentType::json()
     /// );
-    /// # }
     /// ```
     ///
-    /// ```rust
-    /// # extern crate mime;
-    /// # extern crate actix_http;
-    /// use mime::TEXT_HTML;
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::ContentType;
     ///
-    /// # fn main() {
     /// let mut builder = Response::Ok();
-    /// builder.set(
-    ///     ContentType(TEXT_HTML)
+    /// builder.insert_header(
+    ///     ContentType(mime::TEXT_HTML)
     /// );
-    /// # }
     /// ```
     (ContentType, CONTENT_TYPE) => [Mime]
 
@@ -99,6 +92,7 @@ impl ContentType {
     pub fn form_url_encoded() -> ContentType {
         ContentType(mime::APPLICATION_WWW_FORM_URLENCODED)
     }
+
     /// A constructor  to easily create a `Content-Type: image/jpeg` header.
     #[inline]
     pub fn jpeg() -> ContentType {
diff --git a/actix-http/src/header/common/date.rs b/actix-http/src/header/common/date.rs
index 784100e8d..e5ace95e6 100644
--- a/actix-http/src/header/common/date.rs
+++ b/actix-http/src/header/common/date.rs
@@ -19,13 +19,15 @@ header! {
     ///
     /// # Example
     ///
-    /// ```rust
+    /// ```
+    /// use std::time::SystemTime;
     /// use actix_http::Response;
     /// use actix_http::http::header::Date;
-    /// use std::time::SystemTime;
     ///
     /// let mut builder = Response::Ok();
-    /// builder.set(Date(SystemTime::now().into()));
+    /// builder.insert_header(
+    ///     Date(SystemTime::now().into())
+    /// );
     /// ```
     (Date, DATE) => [HttpDate]
 
diff --git a/actix-http/src/header/common/etag.rs b/actix-http/src/header/common/etag.rs
index 325b91cbf..4c1e8d262 100644
--- a/actix-http/src/header/common/etag.rs
+++ b/actix-http/src/header/common/etag.rs
@@ -27,20 +27,24 @@ header! {
     ///
     /// # Examples
     ///
-    /// ```rust
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{ETag, EntityTag};
     ///
     /// let mut builder = Response::Ok();
-    /// builder.set(ETag(EntityTag::new(false, "xyzzy".to_owned())));
+    /// builder.insert_header(
+    ///     ETag(EntityTag::new(false, "xyzzy".to_owned()))
+    /// );
     /// ```
     ///
-    /// ```rust
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{ETag, EntityTag};
     ///
     /// let mut builder = Response::Ok();
-    /// builder.set(ETag(EntityTag::new(true, "xyzzy".to_owned())));
+    /// builder.insert_header(
+    ///     ETag(EntityTag::new(true, "xyzzy".to_owned()))
+    /// );
     /// ```
     (ETag, ETAG) => [EntityTag]
 
diff --git a/actix-http/src/header/common/expires.rs b/actix-http/src/header/common/expires.rs
index 3b9a7873d..79563955d 100644
--- a/actix-http/src/header/common/expires.rs
+++ b/actix-http/src/header/common/expires.rs
@@ -21,14 +21,16 @@ header! {
     ///
     /// # Example
     ///
-    /// ```rust
+    /// ```
+    /// use std::time::{SystemTime, Duration};
     /// use actix_http::Response;
     /// use actix_http::http::header::Expires;
-    /// use std::time::{SystemTime, Duration};
     ///
     /// let mut builder = Response::Ok();
     /// let expiration = SystemTime::now() + Duration::from_secs(60 * 60 * 24);
-    /// builder.set(Expires(expiration.into()));
+    /// builder.insert_header(
+    ///     Expires(expiration.into())
+    /// );
     /// ```
     (Expires, EXPIRES) => [HttpDate]
 
diff --git a/actix-http/src/header/common/if_match.rs b/actix-http/src/header/common/if_match.rs
index 7e0e9a7e0..db255e91a 100644
--- a/actix-http/src/header/common/if_match.rs
+++ b/actix-http/src/header/common/if_match.rs
@@ -29,20 +29,20 @@ header! {
     ///
     /// # Examples
     ///
-    /// ```rust
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::IfMatch;
     ///
     /// let mut builder = Response::Ok();
-    /// builder.set(IfMatch::Any);
+    /// builder.insert_header(IfMatch::Any);
     /// ```
     ///
-    /// ```rust
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{IfMatch, EntityTag};
     ///
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     IfMatch::Items(vec![
     ///         EntityTag::new(false, "xyzzy".to_owned()),
     ///         EntityTag::new(false, "foobar".to_owned()),
diff --git a/actix-http/src/header/common/if_modified_since.rs b/actix-http/src/header/common/if_modified_since.rs
index 39aca595d..99c7e441d 100644
--- a/actix-http/src/header/common/if_modified_since.rs
+++ b/actix-http/src/header/common/if_modified_since.rs
@@ -21,14 +21,16 @@ header! {
     ///
     /// # Example
     ///
-    /// ```rust
+    /// ```
+    /// use std::time::{SystemTime, Duration};
     /// use actix_http::Response;
     /// use actix_http::http::header::IfModifiedSince;
-    /// use std::time::{SystemTime, Duration};
     ///
     /// let mut builder = Response::Ok();
     /// let modified = SystemTime::now() - Duration::from_secs(60 * 60 * 24);
-    /// builder.set(IfModifiedSince(modified.into()));
+    /// builder.insert_header(
+    ///     IfModifiedSince(modified.into())
+    /// );
     /// ```
     (IfModifiedSince, IF_MODIFIED_SINCE) => [HttpDate]
 
diff --git a/actix-http/src/header/common/if_none_match.rs b/actix-http/src/header/common/if_none_match.rs
index 7f6ccb137..464caf1ae 100644
--- a/actix-http/src/header/common/if_none_match.rs
+++ b/actix-http/src/header/common/if_none_match.rs
@@ -31,20 +31,20 @@ header! {
     ///
     /// # Examples
     ///
-    /// ```rust
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::IfNoneMatch;
     ///
     /// let mut builder = Response::Ok();
-    /// builder.set(IfNoneMatch::Any);
+    /// builder.insert_header(IfNoneMatch::Any);
     /// ```
     ///
-    /// ```rust
+    /// ```
     /// use actix_http::Response;
     /// use actix_http::http::header::{IfNoneMatch, EntityTag};
     ///
     /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
     ///     IfNoneMatch::Items(vec![
     ///         EntityTag::new(false, "xyzzy".to_owned()),
     ///         EntityTag::new(false, "foobar".to_owned()),
@@ -73,13 +73,15 @@ mod tests {
     fn test_if_none_match() {
         let mut if_none_match: Result<IfNoneMatch, _>;
 
-        let req = TestRequest::with_header(IF_NONE_MATCH, "*").finish();
+        let req = TestRequest::default()
+            .insert_header((IF_NONE_MATCH, "*"))
+            .finish();
         if_none_match = Header::parse(&req);
         assert_eq!(if_none_match.ok(), Some(IfNoneMatch::Any));
 
-        let req =
-            TestRequest::with_header(IF_NONE_MATCH, &b"\"foobar\", W/\"weak-etag\""[..])
-                .finish();
+        let req = TestRequest::default()
+            .insert_header((IF_NONE_MATCH, &b"\"foobar\", W/\"weak-etag\""[..]))
+            .finish();
 
         if_none_match = Header::parse(&req);
         let mut entities: Vec<EntityTag> = Vec::new();
diff --git a/actix-http/src/header/common/if_range.rs b/actix-http/src/header/common/if_range.rs
index b14ad0391..0a5749505 100644
--- a/actix-http/src/header/common/if_range.rs
+++ b/actix-http/src/header/common/if_range.rs
@@ -5,7 +5,7 @@ use crate::header::{
     self, from_one_raw_str, EntityTag, Header, HeaderName, HeaderValue, HttpDate,
     IntoHeaderValue, InvalidHeaderValue, Writer,
 };
-use crate::httpmessage::HttpMessage;
+use crate::HttpMessage;
 
 /// `If-Range` header, defined in [RFC7233](http://tools.ietf.org/html/rfc7233#section-3.2)
 ///
@@ -35,31 +35,34 @@ use crate::httpmessage::HttpMessage;
 ///
 /// # Examples
 ///
-/// ```rust
+/// ```
 /// use actix_http::Response;
 /// use actix_http::http::header::{EntityTag, IfRange};
 ///
 /// let mut builder = Response::Ok();
-/// builder.set(IfRange::EntityTag(EntityTag::new(
-///     false,
-///     "xyzzy".to_owned(),
-/// )));
+/// builder.insert_header(
+///     IfRange::EntityTag(
+///         EntityTag::new(false, "abc".to_owned())
+///     )
+/// );
 /// ```
 ///
-/// ```rust
-/// use actix_http::Response;
-/// use actix_http::http::header::IfRange;
+/// ```
 /// use std::time::{Duration, SystemTime};
+/// use actix_http::{http::header::IfRange, Response};
 ///
 /// let mut builder = Response::Ok();
 /// let fetched = SystemTime::now() - Duration::from_secs(60 * 60 * 24);
-/// builder.set(IfRange::Date(fetched.into()));
+/// builder.insert_header(
+///     IfRange::Date(fetched.into())
+/// );
 /// ```
 #[derive(Clone, Debug, PartialEq)]
 pub enum IfRange {
-    /// The entity-tag the client has of the resource
+    /// The entity-tag the client has of the resource.
     EntityTag(EntityTag),
-    /// The date when the client retrieved the resource
+
+    /// The date when the client retrieved the resource.
     Date(HttpDate),
 }
 
@@ -98,7 +101,7 @@ impl Display for IfRange {
 impl IntoHeaderValue for IfRange {
     type Error = InvalidHeaderValue;
 
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
         let mut writer = Writer::new();
         let _ = write!(&mut writer, "{}", self);
         HeaderValue::from_maybe_shared(writer.take())
@@ -110,7 +113,8 @@ mod test_if_range {
     use super::IfRange as HeaderField;
     use crate::header::*;
     use std::str;
+
     test_header!(test1, vec![b"Sat, 29 Oct 1994 19:43:31 GMT"]);
-    test_header!(test2, vec![b"\"xyzzy\""]);
+    test_header!(test2, vec![b"\"abc\""]);
     test_header!(test3, vec![b"this-is-invalid"], None::<IfRange>);
 }
diff --git a/actix-http/src/header/common/if_unmodified_since.rs b/actix-http/src/header/common/if_unmodified_since.rs
index d6c099e64..1c2b4af78 100644
--- a/actix-http/src/header/common/if_unmodified_since.rs
+++ b/actix-http/src/header/common/if_unmodified_since.rs
@@ -22,14 +22,16 @@ header! {
     ///
     /// # Example
     ///
-    /// ```rust
+    /// ```
+    /// use std::time::{SystemTime, Duration};
     /// use actix_http::Response;
     /// use actix_http::http::header::IfUnmodifiedSince;
-    /// use std::time::{SystemTime, Duration};
     ///
     /// let mut builder = Response::Ok();
     /// let modified = SystemTime::now() - Duration::from_secs(60 * 60 * 24);
-    /// builder.set(IfUnmodifiedSince(modified.into()));
+    /// builder.insert_header(
+    ///     IfUnmodifiedSince(modified.into())
+    /// );
     /// ```
     (IfUnmodifiedSince, IF_UNMODIFIED_SINCE) => [HttpDate]
 
diff --git a/actix-http/src/header/common/last_modified.rs b/actix-http/src/header/common/last_modified.rs
index cc888ccb0..65608d846 100644
--- a/actix-http/src/header/common/last_modified.rs
+++ b/actix-http/src/header/common/last_modified.rs
@@ -21,14 +21,16 @@ header! {
     ///
     /// # Example
     ///
-    /// ```rust
+    /// ```
+    /// use std::time::{SystemTime, Duration};
     /// use actix_http::Response;
     /// use actix_http::http::header::LastModified;
-    /// use std::time::{SystemTime, Duration};
     ///
     /// let mut builder = Response::Ok();
     /// let modified = SystemTime::now() - Duration::from_secs(60 * 60 * 24);
-    /// builder.set(LastModified(modified.into()));
+    /// builder.insert_header(
+    ///     LastModified(modified.into())
+    /// );
     /// ```
     (LastModified, LAST_MODIFIED) => [HttpDate]
 
diff --git a/actix-http/src/header/common/mod.rs b/actix-http/src/header/common/mod.rs
index 83489b864..90e0a855e 100644
--- a/actix-http/src/header/common/mod.rs
+++ b/actix-http/src/header/common/mod.rs
@@ -3,7 +3,7 @@
 //! ## Mime
 //!
 //! Several header fields use MIME values for their contents. Keeping with the
-//! strongly-typed theme, the [mime](https://docs.rs/mime) crate
+//! strongly-typed theme, the [mime] crate
 //! is used, such as `ContentType(pub Mime)`.
 #![cfg_attr(rustfmt, rustfmt_skip)]
 
@@ -18,6 +18,7 @@ pub use self::content_disposition::{
 };
 pub use self::content_language::ContentLanguage;
 pub use self::content_range::{ContentRange, ContentRangeSpec};
+pub use self::content_encoding::{ContentEncoding};
 pub use self::content_type::ContentType;
 pub use self::date::Date;
 pub use self::etag::ETag;
@@ -83,7 +84,7 @@ macro_rules! test_header {
             let a: Vec<Vec<u8>> = raw.iter().map(|x| x.to_vec()).collect();
             let mut req = test::TestRequest::default();
             for item in a {
-                req = req.header(HeaderField::name(), item).take();
+                req = req.insert_header((HeaderField::name(), item)).take();
             }
             let req = req.finish();
             let value = HeaderField::parse(&req);
@@ -110,7 +111,7 @@ macro_rules! test_header {
             let a: Vec<Vec<u8>> = $raw.iter().map(|x| x.to_vec()).collect();
             let mut req = test::TestRequest::default();
             for item in a {
-                req.header(HeaderField::name(), item);
+                req.insert_header((HeaderField::name(), item));
             }
             let req = req.finish();
             let val = HeaderField::parse(&req);
@@ -168,7 +169,7 @@ macro_rules! header {
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
-            fn try_into(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
+            fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                 use std::fmt::Write;
                 let mut writer = $crate::http::header::Writer::new();
                 let _ = write!(&mut writer, "{}", self);
@@ -204,7 +205,7 @@ macro_rules! header {
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
-            fn try_into(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
+            fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                 use std::fmt::Write;
                 let mut writer = $crate::http::header::Writer::new();
                 let _ = write!(&mut writer, "{}", self);
@@ -240,8 +241,8 @@ macro_rules! header {
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
-            fn try_into(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
-                self.0.try_into()
+            fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
+                self.0.try_into_value()
             }
         }
     };
@@ -289,7 +290,7 @@ macro_rules! header {
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
-            fn try_into(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
+            fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                 use std::fmt::Write;
                 let mut writer = $crate::http::header::Writer::new();
                 let _ = write!(&mut writer, "{}", self);
@@ -333,13 +334,14 @@ macro_rules! header {
 }
 
 mod accept_charset;
-//mod accept_encoding;
+// mod accept_encoding;
 mod accept;
 mod accept_language;
 mod allow;
 mod cache_control;
 mod content_disposition;
 mod content_language;
+mod content_encoding;
 mod content_range;
 mod content_type;
 mod date;
diff --git a/actix-http/src/header/into_pair.rs b/actix-http/src/header/into_pair.rs
new file mode 100644
index 000000000..d0d6e7324
--- /dev/null
+++ b/actix-http/src/header/into_pair.rs
@@ -0,0 +1,117 @@
+use std::convert::TryFrom;
+
+use http::{
+    header::{HeaderName, InvalidHeaderName, InvalidHeaderValue},
+    Error as HttpError, HeaderValue,
+};
+
+use super::{Header, IntoHeaderValue};
+
+/// Transforms structures into header K/V pairs for inserting into `HeaderMap`s.
+pub trait IntoHeaderPair: Sized {
+    type Error: Into<HttpError>;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error>;
+}
+
+#[derive(Debug)]
+pub enum InvalidHeaderPart {
+    Name(InvalidHeaderName),
+    Value(InvalidHeaderValue),
+}
+
+impl From<InvalidHeaderPart> for HttpError {
+    fn from(part_err: InvalidHeaderPart) -> Self {
+        match part_err {
+            InvalidHeaderPart::Name(err) => err.into(),
+            InvalidHeaderPart::Value(err) => err.into(),
+        }
+    }
+}
+
+impl<V> IntoHeaderPair for (HeaderName, V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        let value = value
+            .try_into_value()
+            .map_err(|err| InvalidHeaderPart::Value(err.into()))?;
+        Ok((name, value))
+    }
+}
+
+impl<V> IntoHeaderPair for (&HeaderName, V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        let value = value
+            .try_into_value()
+            .map_err(|err| InvalidHeaderPart::Value(err.into()))?;
+        Ok((name.clone(), value))
+    }
+}
+
+impl<V> IntoHeaderPair for (&[u8], V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        let name = HeaderName::try_from(name).map_err(InvalidHeaderPart::Name)?;
+        let value = value
+            .try_into_value()
+            .map_err(|err| InvalidHeaderPart::Value(err.into()))?;
+        Ok((name, value))
+    }
+}
+
+impl<V> IntoHeaderPair for (&str, V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        let name = HeaderName::try_from(name).map_err(InvalidHeaderPart::Name)?;
+        let value = value
+            .try_into_value()
+            .map_err(|err| InvalidHeaderPart::Value(err.into()))?;
+        Ok((name, value))
+    }
+}
+
+impl<V> IntoHeaderPair for (String, V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        (name.as_str(), value).try_into_header_pair()
+    }
+}
+
+impl<T: Header> IntoHeaderPair for T {
+    type Error = <T as IntoHeaderValue>::Error;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        Ok((T::name(), self.try_into_value()?))
+    }
+}
diff --git a/actix-http/src/header/into_value.rs b/actix-http/src/header/into_value.rs
new file mode 100644
index 000000000..4ba58e726
--- /dev/null
+++ b/actix-http/src/header/into_value.rs
@@ -0,0 +1,131 @@
+use std::convert::TryFrom;
+
+use bytes::Bytes;
+use http::{header::InvalidHeaderValue, Error as HttpError, HeaderValue};
+use mime::Mime;
+
+/// A trait for any object that can be Converted to a `HeaderValue`
+pub trait IntoHeaderValue: Sized {
+    /// The type returned in the event of a conversion error.
+    type Error: Into<HttpError>;
+
+    /// Try to convert value to a HeaderValue.
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error>;
+}
+
+impl IntoHeaderValue for HeaderValue {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        Ok(self)
+    }
+}
+
+impl IntoHeaderValue for &HeaderValue {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        Ok(self.clone())
+    }
+}
+
+impl IntoHeaderValue for &str {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        self.parse()
+    }
+}
+
+impl IntoHeaderValue for &[u8] {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::from_bytes(self)
+    }
+}
+
+impl IntoHeaderValue for Bytes {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::from_maybe_shared(self)
+    }
+}
+
+impl IntoHeaderValue for Vec<u8> {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self)
+    }
+}
+
+impl IntoHeaderValue for String {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self)
+    }
+}
+
+impl IntoHeaderValue for usize {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for i64 {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for u64 {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for i32 {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for u32 {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for Mime {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::from_str(self.as_ref())
+    }
+}
diff --git a/actix-http/src/header/map.rs b/actix-http/src/header/map.rs
index 36c050b8f..106e44edb 100644
--- a/actix-http/src/header/map.rs
+++ b/actix-http/src/header/map.rs
@@ -1,332 +1,563 @@
-use std::collections::hash_map::{self, Entry};
-use std::convert::TryFrom;
+//! A multi-value [`HeaderMap`] and its iterators.
 
-use either::Either;
-use fxhash::FxHashMap;
+use std::{borrow::Cow, collections::hash_map, ops};
+
+use ahash::AHashMap;
 use http::header::{HeaderName, HeaderValue};
+use smallvec::{smallvec, SmallVec};
 
-/// A set of HTTP headers
+use crate::header::AsHeaderName;
+
+/// A multi-map of HTTP headers.
 ///
-/// `HeaderMap` is an multi-map of [`HeaderName`] to values.
+/// `HeaderMap` is a "multi-map" of [`HeaderName`] to one or more [`HeaderValue`]s.
 ///
-/// [`HeaderName`]: struct.HeaderName.html
-#[derive(Debug, Clone)]
+/// # Examples
+/// ```
+/// use actix_http::http::{header, HeaderMap, HeaderValue};
+///
+/// let mut map = HeaderMap::new();
+///
+/// map.insert(header::CONTENT_TYPE, HeaderValue::from_static("text/plain"));
+/// map.insert(header::ORIGIN, HeaderValue::from_static("example.com"));
+///
+/// assert!(map.contains_key(header::CONTENT_TYPE));
+/// assert!(map.contains_key(header::ORIGIN));
+///
+/// let mut removed = map.remove(header::ORIGIN);
+/// assert_eq!(removed.next().unwrap(), "example.com");
+///
+/// assert!(!map.contains_key(header::ORIGIN));
+/// ```
+#[derive(Debug, Clone, Default)]
 pub struct HeaderMap {
-    pub(crate) inner: FxHashMap<HeaderName, Value>,
+    pub(crate) inner: AHashMap<HeaderName, Value>,
 }
 
+/// A bespoke non-empty list for HeaderMap values.
 #[derive(Debug, Clone)]
-pub(crate) enum Value {
-    One(HeaderValue),
-    Multi(Vec<HeaderValue>),
+pub(crate) struct Value {
+    inner: SmallVec<[HeaderValue; 4]>,
 }
 
 impl Value {
-    fn get(&self) -> &HeaderValue {
-        match self {
-            Value::One(ref val) => val,
-            Value::Multi(ref val) => &val[0],
+    fn one(val: HeaderValue) -> Self {
+        Self {
+            inner: smallvec![val],
         }
     }
 
-    fn get_mut(&mut self) -> &mut HeaderValue {
-        match self {
-            Value::One(ref mut val) => val,
-            Value::Multi(ref mut val) => &mut val[0],
-        }
+    fn first(&self) -> &HeaderValue {
+        &self.inner[0]
     }
 
-    fn append(&mut self, val: HeaderValue) {
-        match self {
-            Value::One(_) => {
-                let data = std::mem::replace(self, Value::Multi(vec![val]));
-                match data {
-                    Value::One(val) => self.append(val),
-                    Value::Multi(_) => unreachable!(),
-                }
-            }
-            Value::Multi(ref mut vec) => vec.push(val),
-        }
+    fn first_mut(&mut self) -> &mut HeaderValue {
+        &mut self.inner[0]
+    }
+
+    fn append(&mut self, new_val: HeaderValue) {
+        self.inner.push(new_val)
+    }
+}
+
+impl ops::Deref for Value {
+    type Target = SmallVec<[HeaderValue; 4]>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.inner
     }
 }
 
 impl HeaderMap {
     /// Create an empty `HeaderMap`.
     ///
-    /// The map will be created without any capacity. This function will not
-    /// allocate.
+    /// The map will be created without any capacity; this function will not allocate.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::HeaderMap;
+    /// let map = HeaderMap::new();
+    ///
+    /// assert!(map.is_empty());
+    /// assert_eq!(0, map.capacity());
+    /// ```
     pub fn new() -> Self {
-        HeaderMap {
-            inner: FxHashMap::default(),
-        }
+        HeaderMap::default()
     }
 
     /// Create an empty `HeaderMap` with the specified capacity.
     ///
-    /// The returned map will allocate internal storage in order to hold about
-    /// `capacity` elements without reallocating. However, this is a "best
-    /// effort" as there are usage patterns that could cause additional
-    /// allocations before `capacity` headers are stored in the map.
+    /// The map will be able to hold at least `capacity` elements without needing to reallocate.
+    /// If `capacity` is 0, the map will be created without allocating.
     ///
-    /// More capacity than requested may be allocated.
-    pub fn with_capacity(capacity: usize) -> HeaderMap {
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::HeaderMap;
+    /// let map = HeaderMap::with_capacity(16);
+    ///
+    /// assert!(map.is_empty());
+    /// assert!(map.capacity() >= 16);
+    /// ```
+    pub fn with_capacity(capacity: usize) -> Self {
         HeaderMap {
-            inner: FxHashMap::with_capacity_and_hasher(capacity, Default::default()),
+            inner: AHashMap::with_capacity(capacity),
         }
     }
 
-    /// Returns the number of keys stored in the map.
+    /// Create new `HeaderMap` from a `http::HeaderMap`-like drain.
+    pub(crate) fn from_drain<I>(mut drain: I) -> Self
+    where
+        I: Iterator<Item = (Option<HeaderName>, HeaderValue)>,
+    {
+        let (first_name, first_value) = match drain.next() {
+            None => return HeaderMap::new(),
+            Some((name, val)) => {
+                let name = name.expect("drained first item had no name");
+                (name, val)
+            }
+        };
+
+        let (lb, ub) = drain.size_hint();
+        let capacity = ub.unwrap_or(lb);
+
+        let mut map = HeaderMap::with_capacity(capacity);
+        map.append(first_name.clone(), first_value);
+
+        let (map, _) =
+            drain.fold((map, first_name), |(mut map, prev_name), (name, value)| {
+                let name = name.unwrap_or(prev_name);
+                map.append(name.clone(), value);
+                (map, name)
+            });
+
+        map
+    }
+
+    /// Returns the number of values stored in the map.
     ///
-    /// This number could be be less than or equal to actual headers stored in
-    /// the map.
+    /// See also: [`len_keys`](Self::len_keys).
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    /// assert_eq!(map.len(), 0);
+    ///
+    /// map.insert(header::ACCEPT, HeaderValue::from_static("text/plain"));
+    /// map.insert(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    /// assert_eq!(map.len(), 2);
+    ///
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("two=2"));
+    /// assert_eq!(map.len(), 3);
+    /// ```
     pub fn len(&self) -> usize {
+        self.inner
+            .iter()
+            .fold(0, |acc, (_, values)| acc + values.len())
+    }
+
+    /// Returns the number of _keys_ stored in the map.
+    ///
+    /// The number of values stored will be at least this number. See also: [`Self::len`].
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    /// assert_eq!(map.len_keys(), 0);
+    ///
+    /// map.insert(header::ACCEPT, HeaderValue::from_static("text/plain"));
+    /// map.insert(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    /// assert_eq!(map.len_keys(), 2);
+    ///
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("two=2"));
+    /// assert_eq!(map.len_keys(), 2);
+    /// ```
+    pub fn len_keys(&self) -> usize {
         self.inner.len()
     }
 
     /// Returns true if the map contains no elements.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    /// assert!(map.is_empty());
+    ///
+    /// map.insert(header::ACCEPT, HeaderValue::from_static("text/plain"));
+    /// assert!(!map.is_empty());
+    /// ```
     pub fn is_empty(&self) -> bool {
         self.inner.len() == 0
     }
 
-    /// Clears the map, removing all key-value pairs. Keeps the allocated memory
-    /// for reuse.
+    /// Clears the map, removing all name-value pairs.
+    ///
+    /// Keeps the allocated memory for reuse.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    ///
+    /// map.insert(header::ACCEPT, HeaderValue::from_static("text/plain"));
+    /// map.insert(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    /// assert_eq!(map.len(), 2);
+    ///
+    /// map.clear();
+    /// assert!(map.is_empty());
+    /// ```
     pub fn clear(&mut self) {
         self.inner.clear();
     }
 
-    /// Returns the number of headers the map can hold without reallocating.
+    fn get_value(&self, key: impl AsHeaderName) -> Option<&Value> {
+        match key.try_as_name().ok()? {
+            Cow::Borrowed(name) => self.inner.get(name),
+            Cow::Owned(name) => self.inner.get(&name),
+        }
+    }
+
+    /// Returns a reference to the _first_ value associated with a header name.
     ///
-    /// This number is an approximation as certain usage patterns could cause
-    /// additional allocations before the returned capacity is filled.
+    /// Returns `None` if there is no value associated with the key.
+    ///
+    /// Even when multiple values are associated with the key, the "first" one is returned but is
+    /// not guaranteed to be chosen with any particular order; though, the returned item will be
+    /// consistent for each call to `get` if the map has not changed.
+    ///
+    /// See also: [`get_all`](Self::get_all).
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    ///
+    /// map.insert(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    ///
+    /// let cookie = map.get(header::SET_COOKIE).unwrap();
+    /// assert_eq!(cookie, "one=1");
+    ///
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("two=2"));
+    /// assert_eq!(map.get(header::SET_COOKIE).unwrap(), "one=1");
+    ///
+    /// assert_eq!(map.get(header::SET_COOKIE), map.get("set-cookie"));
+    /// assert_eq!(map.get(header::SET_COOKIE), map.get("Set-Cookie"));
+    ///
+    /// assert!(map.get(header::HOST).is_none());
+    /// assert!(map.get("INVALID HEADER NAME").is_none());
+    /// ```
+    pub fn get(&self, key: impl AsHeaderName) -> Option<&HeaderValue> {
+        self.get_value(key).map(|val| val.first())
+    }
+
+    /// Returns a mutable reference to the _first_ value associated a header name.
+    ///
+    /// Returns `None` if there is no value associated with the key.
+    ///
+    /// Even when multiple values are associated with the key, the "first" one is returned but is
+    /// not guaranteed to be chosen with any particular order; though, the returned item will be
+    /// consistent for each call to `get_mut` if the map has not changed.
+    ///
+    /// See also: [`get_all`](Self::get_all).
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    ///
+    /// map.insert(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    ///
+    /// let mut cookie = map.get_mut(header::SET_COOKIE).unwrap();
+    /// assert_eq!(cookie, "one=1");
+    ///
+    /// *cookie = HeaderValue::from_static("three=3");
+    /// assert_eq!(map.get(header::SET_COOKIE).unwrap(), "three=3");
+    ///
+    /// assert!(map.get(header::HOST).is_none());
+    /// assert!(map.get("INVALID HEADER NAME").is_none());
+    /// ```
+    pub fn get_mut(&mut self, key: impl AsHeaderName) -> Option<&mut HeaderValue> {
+        match key.try_as_name().ok()? {
+            Cow::Borrowed(name) => self.inner.get_mut(name).map(|v| v.first_mut()),
+            Cow::Owned(name) => self.inner.get_mut(&name).map(|v| v.first_mut()),
+        }
+    }
+
+    /// Returns an iterator over all values associated with a header name.
+    ///
+    /// The returned iterator does not incur any allocations and will yield no items if there are no
+    /// values associated with the key. Iteration order is **not** guaranteed to be the same as
+    /// insertion order.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    ///
+    /// let mut none_iter = map.get_all(header::ORIGIN);
+    /// assert!(none_iter.next().is_none());
+    ///
+    /// map.insert(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("two=2"));
+    ///
+    /// let mut set_cookies_iter = map.get_all(header::SET_COOKIE);
+    /// assert_eq!(set_cookies_iter.next().unwrap(), "one=1");
+    /// assert_eq!(set_cookies_iter.next().unwrap(), "two=2");
+    /// assert!(set_cookies_iter.next().is_none());
+    /// ```
+    pub fn get_all(&self, key: impl AsHeaderName) -> GetAll<'_> {
+        GetAll::new(self.get_value(key))
+    }
+
+    // TODO: get_all_mut ?
+
+    /// Returns `true` if the map contains a value for the specified key.
+    ///
+    /// Invalid header names will simply return false.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    /// assert!(!map.contains_key(header::ACCEPT));
+    ///
+    /// map.insert(header::ACCEPT, HeaderValue::from_static("text/plain"));
+    /// assert!(map.contains_key(header::ACCEPT));
+    /// ```
+    pub fn contains_key(&self, key: impl AsHeaderName) -> bool {
+        match key.try_as_name() {
+            Ok(Cow::Borrowed(name)) => self.inner.contains_key(name),
+            Ok(Cow::Owned(name)) => self.inner.contains_key(&name),
+            Err(_) => false,
+        }
+    }
+
+    /// Inserts a name-value pair into the map.
+    ///
+    /// If the map already contained this key, the new value is associated with the key and all
+    /// previous values are removed and returned as a `Removed` iterator. The key is not updated;
+    /// this matters for types that can be `==` without being identical.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    ///
+    /// map.insert(header::ACCEPT, HeaderValue::from_static("text/plain"));
+    /// assert!(map.contains_key(header::ACCEPT));
+    /// assert_eq!(map.len(), 1);
+    ///
+    /// let mut removed = map.insert(header::ACCEPT, HeaderValue::from_static("text/csv"));
+    /// assert_eq!(removed.next().unwrap(), "text/plain");
+    /// assert!(removed.next().is_none());
+    ///
+    /// assert_eq!(map.len(), 1);
+    /// ```
+    pub fn insert(&mut self, key: HeaderName, val: HeaderValue) -> Removed {
+        let value = self.inner.insert(key, Value::one(val));
+        Removed::new(value)
+    }
+
+    /// Inserts a name-value pair into the map.
+    ///
+    /// If the map already contained this key, the new value is added to the list of values
+    /// currently associated with the key. The key is not updated; this matters for types that can
+    /// be `==` without being identical.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    ///
+    /// map.append(header::HOST, HeaderValue::from_static("example.com"));
+    /// assert_eq!(map.len(), 1);
+    ///
+    /// map.append(header::ACCEPT, HeaderValue::from_static("text/csv"));
+    /// assert_eq!(map.len(), 2);
+    ///
+    /// map.append(header::ACCEPT, HeaderValue::from_static("text/html"));
+    /// assert_eq!(map.len(), 3);
+    /// ```
+    pub fn append(&mut self, key: HeaderName, value: HeaderValue) {
+        match self.inner.entry(key) {
+            hash_map::Entry::Occupied(mut entry) => {
+                entry.get_mut().append(value);
+            }
+            hash_map::Entry::Vacant(entry) => {
+                entry.insert(Value::one(value));
+            }
+        };
+    }
+
+    /// Removes all headers for a particular header name from the map.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    ///
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("one=2"));
+    ///
+    /// assert_eq!(map.len(), 2);
+    ///
+    /// let mut removed = map.remove(header::SET_COOKIE);
+    /// assert_eq!(removed.next().unwrap(), "one=1");
+    /// assert_eq!(removed.next().unwrap(), "one=2");
+    /// assert!(removed.next().is_none());
+    ///
+    /// assert!(map.is_empty());
+    pub fn remove(&mut self, key: impl AsHeaderName) -> Removed {
+        let value = match key.try_as_name() {
+            Ok(Cow::Borrowed(name)) => self.inner.remove(name),
+            Ok(Cow::Owned(name)) => self.inner.remove(&name),
+            Err(_) => None,
+        };
+
+        Removed::new(value)
+    }
+
+    /// Returns the number of single-value headers the map can hold without needing to reallocate.
+    ///
+    /// Since this is a multi-value map, the actual capacity is much larger when considering
+    /// each header name can be associated with an arbitrary number of values. The effect is that
+    /// the size of `len` may be greater than `capacity` since it counts all the values.
+    /// Conversely, [`len_keys`](Self::len_keys) will never be larger than capacity.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::HeaderMap;
+    /// let map = HeaderMap::with_capacity(16);
+    ///
+    /// assert!(map.is_empty());
+    /// assert!(map.capacity() >= 16);
+    /// ```
     pub fn capacity(&self) -> usize {
         self.inner.capacity()
     }
 
-    /// Reserves capacity for at least `additional` more headers to be inserted
-    /// into the `HeaderMap`.
+    /// Reserves capacity for at least `additional` more headers to be inserted in the map.
     ///
-    /// The header map may reserve more space to avoid frequent reallocations.
-    /// Like with `with_capacity`, this will be a "best effort" to avoid
-    /// allocations until `additional` more headers are inserted. Certain usage
-    /// patterns could cause additional allocations before the number is
-    /// reached.
+    /// The header map may reserve more space to avoid frequent reallocations. Additional capacity
+    /// only considers single-value headers.
+    ///
+    /// # Panics
+    /// Panics if the new allocation size overflows usize.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::HeaderMap;
+    /// let mut map = HeaderMap::with_capacity(2);
+    /// assert!(map.capacity() >= 2);
+    ///
+    /// map.reserve(100);
+    /// assert!(map.capacity() >= 102);
+    ///
+    /// assert!(map.is_empty());
+    /// ```
     pub fn reserve(&mut self, additional: usize) {
         self.inner.reserve(additional)
     }
 
-    /// Returns a reference to the value associated with the key.
+    /// An iterator over all name-value pairs.
     ///
-    /// If there are multiple values associated with the key, then the first one
-    /// is returned. Use `get_all` to get all values associated with a given
-    /// key. Returns `None` if there are no values associated with the key.
-    pub fn get<N: AsName>(&self, name: N) -> Option<&HeaderValue> {
-        self.get2(name).map(|v| v.get())
-    }
-
-    fn get2<N: AsName>(&self, name: N) -> Option<&Value> {
-        match name.as_name() {
-            Either::Left(name) => self.inner.get(name),
-            Either::Right(s) => {
-                if let Ok(name) = HeaderName::try_from(s) {
-                    self.inner.get(&name)
-                } else {
-                    None
-                }
-            }
-        }
-    }
-
-    /// Returns a view of all values associated with a key.
+    /// Names will be yielded for each associated value. So, if a key has 3 associated values, it
+    /// will be yielded 3 times. The iteration order should be considered arbitrary.
     ///
-    /// The returned view does not incur any allocations and allows iterating
-    /// the values associated with the key.  See [`GetAll`] for more details.
-    /// Returns `None` if there are no values associated with the key.
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
     ///
-    /// [`GetAll`]: struct.GetAll.html
-    pub fn get_all<N: AsName>(&self, name: N) -> GetAll<'_> {
-        GetAll {
-            idx: 0,
-            item: self.get2(name),
-        }
-    }
-
-    /// Returns a mutable reference to the value associated with the key.
+    /// let mut iter = map.iter();
+    /// assert!(iter.next().is_none());
     ///
-    /// If there are multiple values associated with the key, then the first one
-    /// is returned. Use `entry` to get all values associated with a given
-    /// key. Returns `None` if there are no values associated with the key.
-    pub fn get_mut<N: AsName>(&mut self, name: N) -> Option<&mut HeaderValue> {
-        match name.as_name() {
-            Either::Left(name) => self.inner.get_mut(name).map(|v| v.get_mut()),
-            Either::Right(s) => {
-                if let Ok(name) = HeaderName::try_from(s) {
-                    self.inner.get_mut(&name).map(|v| v.get_mut())
-                } else {
-                    None
-                }
-            }
-        }
-    }
-
-    /// Returns true if the map contains a value for the specified key.
-    pub fn contains_key<N: AsName>(&self, key: N) -> bool {
-        match key.as_name() {
-            Either::Left(name) => self.inner.contains_key(name),
-            Either::Right(s) => {
-                if let Ok(name) = HeaderName::try_from(s) {
-                    self.inner.contains_key(&name)
-                } else {
-                    false
-                }
-            }
-        }
-    }
-
-    /// An iterator visiting all key-value pairs.
+    /// map.append(header::HOST, HeaderValue::from_static("duck.com"));
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("two=2"));
     ///
-    /// The iteration order is arbitrary, but consistent across platforms for
-    /// the same crate version. Each key will be yielded once per associated
-    /// value. So, if a key has 3 associated values, it will be yielded 3 times.
+    /// let mut iter = map.iter();
+    /// assert!(iter.next().is_some());
+    /// assert!(iter.next().is_some());
+    /// assert!(iter.next().is_some());
+    /// assert!(iter.next().is_none());
+    ///
+    /// let pairs = map.iter().collect::<Vec<_>>();
+    /// assert!(pairs.contains(&(&header::HOST, &HeaderValue::from_static("duck.com"))));
+    /// assert!(pairs.contains(&(&header::SET_COOKIE, &HeaderValue::from_static("one=1"))));
+    /// assert!(pairs.contains(&(&header::SET_COOKIE, &HeaderValue::from_static("two=2"))));
+    /// ```
     pub fn iter(&self) -> Iter<'_> {
         Iter::new(self.inner.iter())
     }
 
-    /// An iterator visiting all keys.
+    /// An iterator over all contained header names.
     ///
-    /// The iteration order is arbitrary, but consistent across platforms for
-    /// the same crate version. Each key will be yielded only once even if it
-    /// has multiple associated values.
+    /// Each name will only be yielded once even if it has multiple associated values. The iteration
+    /// order should be considered arbitrary.
+    ///
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
+    ///
+    /// let mut iter = map.keys();
+    /// assert!(iter.next().is_none());
+    ///
+    /// map.append(header::HOST, HeaderValue::from_static("duck.com"));
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("two=2"));
+    ///
+    /// let keys = map.keys().cloned().collect::<Vec<_>>();
+    /// assert_eq!(keys.len(), 2);
+    /// assert!(keys.contains(&header::HOST));
+    /// assert!(keys.contains(&header::SET_COOKIE));
+    /// ```
     pub fn keys(&self) -> Keys<'_> {
         Keys(self.inner.keys())
     }
 
-    /// Inserts a key-value pair into the map.
+    /// Clears the map, returning all name-value sets as an iterator.
     ///
-    /// If the map did not previously have this key present, then `None` is
-    /// returned.
+    /// Header names will only be yielded for the first value in each set. All items that are
+    /// yielded without a name and after an item with a name are associated with that same name.
+    /// The first item will always contain a name.
     ///
-    /// If the map did have this key present, the new value is associated with
-    /// the key and all previous values are removed. **Note** that only a single
-    /// one of the previous values is returned. If there are multiple values
-    /// that have been previously associated with the key, then the first one is
-    /// returned. See `insert_mult` on `OccupiedEntry` for an API that returns
-    /// all values.
+    /// Keeps the allocated memory for reuse.
+    /// # Examples
+    /// ```
+    /// # use actix_http::http::{header, HeaderMap, HeaderValue};
+    /// let mut map = HeaderMap::new();
     ///
-    /// The key is not updated, though; this matters for types that can be `==`
-    /// without being identical.
-    pub fn insert(&mut self, key: HeaderName, val: HeaderValue) {
-        let _ = self.inner.insert(key, Value::One(val));
-    }
-
-    /// Inserts a key-value pair into the map.
+    /// let mut iter = map.drain();
+    /// assert!(iter.next().is_none());
+    /// drop(iter);
     ///
-    /// If the map did not previously have this key present, then `false` is
-    /// returned.
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("one=1"));
+    /// map.append(header::SET_COOKIE, HeaderValue::from_static("two=2"));
     ///
-    /// If the map did have this key present, the new value is pushed to the end
-    /// of the list of values currently associated with the key. The key is not
-    /// updated, though; this matters for types that can be `==` without being
-    /// identical.
-    pub fn append(&mut self, key: HeaderName, value: HeaderValue) {
-        match self.inner.entry(key) {
-            Entry::Occupied(mut entry) => entry.get_mut().append(value),
-            Entry::Vacant(entry) => {
-                entry.insert(Value::One(value));
-            }
-        }
-    }
-
-    /// Removes all headers for a particular header name from the map.
-    pub fn remove<N: AsName>(&mut self, key: N) {
-        match key.as_name() {
-            Either::Left(name) => {
-                let _ = self.inner.remove(name);
-            }
-            Either::Right(s) => {
-                if let Ok(name) = HeaderName::try_from(s) {
-                    let _ = self.inner.remove(&name);
-                }
-            }
-        }
+    /// let mut iter = map.drain();
+    /// assert_eq!(iter.next().unwrap(), (Some(header::SET_COOKIE), HeaderValue::from_static("one=1")));
+    /// assert_eq!(iter.next().unwrap(), (None, HeaderValue::from_static("two=2")));
+    /// drop(iter);
+    ///
+    /// assert!(map.is_empty());
+    /// ```
+    pub fn drain(&mut self) -> Drain<'_> {
+        Drain::new(self.inner.drain())
     }
 }
 
-#[doc(hidden)]
-pub trait AsName {
-    fn as_name(&self) -> Either<&HeaderName, &str>;
-}
-
-impl AsName for HeaderName {
-    fn as_name(&self) -> Either<&HeaderName, &str> {
-        Either::Left(self)
-    }
-}
-
-impl<'a> AsName for &'a HeaderName {
-    fn as_name(&self) -> Either<&HeaderName, &str> {
-        Either::Left(self)
-    }
-}
-
-impl<'a> AsName for &'a str {
-    fn as_name(&self) -> Either<&HeaderName, &str> {
-        Either::Right(self)
-    }
-}
-
-impl AsName for String {
-    fn as_name(&self) -> Either<&HeaderName, &str> {
-        Either::Right(self.as_str())
-    }
-}
-
-impl<'a> AsName for &'a String {
-    fn as_name(&self) -> Either<&HeaderName, &str> {
-        Either::Right(self.as_str())
-    }
-}
-
-pub struct GetAll<'a> {
-    idx: usize,
-    item: Option<&'a Value>,
-}
-
-impl<'a> Iterator for GetAll<'a> {
-    type Item = &'a HeaderValue;
+/// Note that this implementation will clone a [HeaderName] for each value.
+impl IntoIterator for HeaderMap {
+    type Item = (HeaderName, HeaderValue);
+    type IntoIter = IntoIter;
 
     #[inline]
-    fn next(&mut self) -> Option<&'a HeaderValue> {
-        if let Some(ref val) = self.item {
-            match val {
-                Value::One(ref val) => {
-                    self.item.take();
-                    Some(val)
-                }
-                Value::Multi(ref vec) => {
-                    if self.idx < vec.len() {
-                        let item = Some(&vec[self.idx]);
-                        self.idx += 1;
-                        item
-                    } else {
-                        self.item.take();
-                        None
-                    }
-                }
-            }
-        } else {
-            None
-        }
-    }
-}
-
-pub struct Keys<'a>(hash_map::Keys<'a, HeaderName, Value>);
-
-impl<'a> Iterator for Keys<'a> {
-    type Item = &'a HeaderName;
-
-    #[inline]
-    fn next(&mut self) -> Option<&'a HeaderName> {
-        self.0.next()
+    fn into_iter(self) -> Self::IntoIter {
+        IntoIter::new(self.inner.into_iter())
     }
 }
 
@@ -334,23 +565,116 @@ impl<'a> IntoIterator for &'a HeaderMap {
     type Item = (&'a HeaderName, &'a HeaderValue);
     type IntoIter = Iter<'a>;
 
+    #[inline]
     fn into_iter(self) -> Self::IntoIter {
-        self.iter()
+        Iter::new(self.inner.iter())
     }
 }
 
-pub struct Iter<'a> {
+/// Iterator for all values with the same header name.
+///
+/// See [`HeaderMap::get_all`].
+#[derive(Debug)]
+pub struct GetAll<'a> {
     idx: usize,
-    current: Option<(&'a HeaderName, &'a Vec<HeaderValue>)>,
-    iter: hash_map::Iter<'a, HeaderName, Value>,
+    value: Option<&'a Value>,
+}
+
+impl<'a> GetAll<'a> {
+    fn new(value: Option<&'a Value>) -> Self {
+        Self { idx: 0, value }
+    }
+}
+
+impl<'a> Iterator for GetAll<'a> {
+    type Item = &'a HeaderValue;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let val = self.value?;
+
+        match val.get(self.idx) {
+            Some(val) => {
+                self.idx += 1;
+                Some(val)
+            }
+            None => {
+                // current index is none; remove value to fast-path future next calls
+                self.value = None;
+                None
+            }
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        match self.value {
+            Some(val) => (val.len(), Some(val.len())),
+            None => (0, Some(0)),
+        }
+    }
+}
+
+/// Iterator for owned [`HeaderValue`]s with the same associated [`HeaderName`] returned from methods
+/// on [`HeaderMap`] that remove or replace items.
+#[derive(Debug)]
+pub struct Removed {
+    inner: Option<smallvec::IntoIter<[HeaderValue; 4]>>,
+}
+
+impl<'a> Removed {
+    fn new(value: Option<Value>) -> Self {
+        let inner = value.map(|value| value.inner.into_iter());
+        Self { inner }
+    }
+}
+
+impl Iterator for Removed {
+    type Item = HeaderValue;
+
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.as_mut()?.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        match self.inner {
+            Some(ref iter) => iter.size_hint(),
+            None => (0, None),
+        }
+    }
+}
+
+/// Iterator over all [`HeaderName`]s in the map.
+#[derive(Debug)]
+pub struct Keys<'a>(hash_map::Keys<'a, HeaderName, Value>);
+
+impl<'a> Iterator for Keys<'a> {
+    type Item = &'a HeaderName;
+
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+        self.0.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.0.size_hint()
+    }
+}
+
+#[derive(Debug)]
+pub struct Iter<'a> {
+    inner: hash_map::Iter<'a, HeaderName, Value>,
+    multi_inner: Option<(&'a HeaderName, &'a SmallVec<[HeaderValue; 4]>)>,
+    multi_idx: usize,
 }
 
 impl<'a> Iter<'a> {
     fn new(iter: hash_map::Iter<'a, HeaderName, Value>) -> Self {
         Self {
-            iter,
-            idx: 0,
-            current: None,
+            inner: iter,
+            multi_idx: 0,
+            multi_inner: None,
         }
     }
 }
@@ -358,28 +682,272 @@ impl<'a> Iter<'a> {
 impl<'a> Iterator for Iter<'a> {
     type Item = (&'a HeaderName, &'a HeaderValue);
 
-    #[inline]
-    fn next(&mut self) -> Option<(&'a HeaderName, &'a HeaderValue)> {
-        if let Some(ref mut item) = self.current {
-            if self.idx < item.1.len() {
-                let item = (item.0, &item.1[self.idx]);
-                self.idx += 1;
-                return Some(item);
-            } else {
-                self.idx = 0;
-                self.current.take();
-            }
-        }
-        if let Some(item) = self.iter.next() {
-            match item.1 {
-                Value::One(ref value) => Some((item.0, value)),
-                Value::Multi(ref vec) => {
-                    self.current = Some((item.0, vec));
-                    self.next()
+    fn next(&mut self) -> Option<Self::Item> {
+        // handle in-progress multi value lists first
+        if let Some((ref name, ref mut vals)) = self.multi_inner {
+            match vals.get(self.multi_idx) {
+                Some(val) => {
+                    self.multi_idx += 1;
+                    return Some((name, val));
+                }
+                None => {
+                    // no more items in value list; reset state
+                    self.multi_idx = 0;
+                    self.multi_inner = None;
                 }
             }
-        } else {
-            None
+        }
+
+        let (name, value) = self.inner.next()?;
+
+        // set up new inner iter and recurse into it
+        self.multi_inner = Some((name, &value.inner));
+        self.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        // take inner lower bound
+        // make no attempt at an upper bound
+        (self.inner.size_hint().0, None)
+    }
+}
+
+/// Iterator over drained name-value pairs.
+///
+/// Iterator items are `(Option<HeaderName>, HeaderValue)` to avoid cloning.
+#[derive(Debug)]
+pub struct Drain<'a> {
+    inner: hash_map::Drain<'a, HeaderName, Value>,
+    multi_inner: Option<(Option<HeaderName>, SmallVec<[HeaderValue; 4]>)>,
+    multi_idx: usize,
+}
+
+impl<'a> Drain<'a> {
+    fn new(iter: hash_map::Drain<'a, HeaderName, Value>) -> Self {
+        Self {
+            inner: iter,
+            multi_inner: None,
+            multi_idx: 0,
         }
     }
 }
+
+impl<'a> Iterator for Drain<'a> {
+    type Item = (Option<HeaderName>, HeaderValue);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        // handle in-progress multi value iterators first
+        if let Some((ref mut name, ref mut vals)) = self.multi_inner {
+            if !vals.is_empty() {
+                // OPTIMIZE: array removals
+                return Some((name.take(), vals.remove(0)));
+            } else {
+                // no more items in value iterator; reset state
+                self.multi_inner = None;
+                self.multi_idx = 0;
+            }
+        }
+
+        let (name, value) = self.inner.next()?;
+
+        // set up new inner iter and recurse into it
+        self.multi_inner = Some((Some(name), value.inner));
+        self.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        // take inner lower bound
+        // make no attempt at an upper bound
+        (self.inner.size_hint().0, None)
+    }
+}
+
+/// Iterator over owned name-value pairs.
+///
+/// Implementation necessarily clones header names for each value.
+#[derive(Debug)]
+pub struct IntoIter {
+    inner: hash_map::IntoIter<HeaderName, Value>,
+    multi_inner: Option<(HeaderName, smallvec::IntoIter<[HeaderValue; 4]>)>,
+}
+
+impl IntoIter {
+    fn new(inner: hash_map::IntoIter<HeaderName, Value>) -> Self {
+        Self {
+            inner,
+            multi_inner: None,
+        }
+    }
+}
+
+impl Iterator for IntoIter {
+    type Item = (HeaderName, HeaderValue);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        // handle in-progress multi value iterators first
+        if let Some((ref name, ref mut vals)) = self.multi_inner {
+            match vals.next() {
+                Some(val) => {
+                    return Some((name.clone(), val));
+                }
+                None => {
+                    // no more items in value iterator; reset state
+                    self.multi_inner = None;
+                }
+            }
+        }
+
+        let (name, value) = self.inner.next()?;
+
+        // set up new inner iter and recurse into it
+        self.multi_inner = Some((name, value.inner.into_iter()));
+        self.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        // take inner lower bound
+        // make no attempt at an upper bound
+        (self.inner.size_hint().0, None)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use http::header;
+
+    use super::*;
+
+    #[test]
+    fn create() {
+        let map = HeaderMap::new();
+        assert_eq!(map.len(), 0);
+        assert_eq!(map.capacity(), 0);
+
+        let map = HeaderMap::with_capacity(16);
+        assert_eq!(map.len(), 0);
+        assert!(map.capacity() >= 16);
+    }
+
+    #[test]
+    fn insert() {
+        let mut map = HeaderMap::new();
+
+        map.insert(header::LOCATION, HeaderValue::from_static("/test"));
+        assert_eq!(map.len(), 1);
+    }
+
+    #[test]
+    fn contains() {
+        let mut map = HeaderMap::new();
+        assert!(!map.contains_key(header::LOCATION));
+
+        map.insert(header::LOCATION, HeaderValue::from_static("/test"));
+        assert!(map.contains_key(header::LOCATION));
+        assert!(map.contains_key("Location"));
+        assert!(map.contains_key("Location".to_owned()));
+        assert!(map.contains_key("location"));
+    }
+
+    #[test]
+    fn entries_iter() {
+        let mut map = HeaderMap::new();
+
+        map.append(header::HOST, HeaderValue::from_static("duck.com"));
+        map.append(header::COOKIE, HeaderValue::from_static("one=1"));
+        map.append(header::COOKIE, HeaderValue::from_static("two=2"));
+
+        let mut iter = map.iter();
+        assert!(iter.next().is_some());
+        assert!(iter.next().is_some());
+        assert!(iter.next().is_some());
+        assert!(iter.next().is_none());
+
+        let pairs = map.iter().collect::<Vec<_>>();
+        assert!(pairs.contains(&(&header::HOST, &HeaderValue::from_static("duck.com"))));
+        assert!(pairs.contains(&(&header::COOKIE, &HeaderValue::from_static("one=1"))));
+        assert!(pairs.contains(&(&header::COOKIE, &HeaderValue::from_static("two=2"))));
+    }
+
+    #[test]
+    fn drain_iter() {
+        let mut map = HeaderMap::new();
+
+        map.append(header::COOKIE, HeaderValue::from_static("one=1"));
+        map.append(header::COOKIE, HeaderValue::from_static("two=2"));
+
+        let mut vals = vec![];
+        let mut iter = map.drain();
+
+        let (name, val) = iter.next().unwrap();
+        assert_eq!(name, Some(header::COOKIE));
+        vals.push(val);
+
+        let (name, val) = iter.next().unwrap();
+        assert!(name.is_none());
+        vals.push(val);
+
+        assert!(vals.contains(&HeaderValue::from_static("one=1")));
+        assert!(vals.contains(&HeaderValue::from_static("two=2")));
+
+        assert!(iter.next().is_none());
+        drop(iter);
+
+        assert!(map.is_empty());
+    }
+
+    #[test]
+    fn entries_into_iter() {
+        let mut map = HeaderMap::new();
+
+        map.append(header::HOST, HeaderValue::from_static("duck.com"));
+        map.append(header::COOKIE, HeaderValue::from_static("one=1"));
+        map.append(header::COOKIE, HeaderValue::from_static("two=2"));
+
+        let mut iter = map.into_iter();
+        assert!(iter.next().is_some());
+        assert!(iter.next().is_some());
+        assert!(iter.next().is_some());
+        assert!(iter.next().is_none());
+    }
+
+    #[test]
+    fn iter_and_into_iter_same_order() {
+        let mut map = HeaderMap::new();
+
+        map.append(header::HOST, HeaderValue::from_static("duck.com"));
+        map.append(header::COOKIE, HeaderValue::from_static("one=1"));
+        map.append(header::COOKIE, HeaderValue::from_static("two=2"));
+
+        let mut iter = map.iter();
+        let mut into_iter = map.clone().into_iter();
+
+        assert_eq!(iter.next().map(owned_pair), into_iter.next());
+        assert_eq!(iter.next().map(owned_pair), into_iter.next());
+        assert_eq!(iter.next().map(owned_pair), into_iter.next());
+        assert_eq!(iter.next().map(owned_pair), into_iter.next());
+    }
+
+    #[test]
+    fn get_all_and_remove_same_order() {
+        let mut map = HeaderMap::new();
+
+        map.append(header::COOKIE, HeaderValue::from_static("one=1"));
+        map.append(header::COOKIE, HeaderValue::from_static("two=2"));
+
+        let mut vals = map.get_all(header::COOKIE);
+        let mut removed = map.clone().remove(header::COOKIE);
+
+        assert_eq!(vals.next(), removed.next().as_ref());
+        assert_eq!(vals.next(), removed.next().as_ref());
+        assert_eq!(vals.next(), removed.next().as_ref());
+    }
+
+    fn owned_pair<'a>(
+        (name, val): (&'a HeaderName, &'a HeaderValue),
+    ) -> (HeaderName, HeaderValue) {
+        (name.clone(), val.clone())
+    }
+}
diff --git a/actix-http/src/header/mod.rs b/actix-http/src/header/mod.rs
index 46fb31a62..1100a959d 100644
--- a/actix-http/src/header/mod.rs
+++ b/actix-http/src/header/mod.rs
@@ -1,35 +1,39 @@
-//! Various http headers
-// This is mostly copy of [hyper](https://github.com/hyperium/hyper/tree/master/src/header)
+//! Typed HTTP headers, pre-defined `HeaderName`s, traits for parsing and conversion, and other
+//! header utility methods.
 
-use std::convert::TryFrom;
-use std::{fmt, str::FromStr};
+use std::fmt;
 
 use bytes::{Bytes, BytesMut};
-use http::Error as HttpError;
-use mime::Mime;
 use percent_encoding::{AsciiSet, CONTROLS};
 
 pub use http::header::*;
 
 use crate::error::ParseError;
-use crate::httpmessage::HttpMessage;
+use crate::HttpMessage;
+
+mod as_name;
+mod into_pair;
+mod into_value;
+mod utils;
 
 mod common;
 pub(crate) mod map;
 mod shared;
+
 pub use self::common::*;
 #[doc(hidden)]
 pub use self::shared::*;
 
+pub use self::as_name::AsHeaderName;
+pub use self::into_pair::IntoHeaderPair;
+pub use self::into_value::IntoHeaderValue;
 #[doc(hidden)]
 pub use self::map::GetAll;
 pub use self::map::HeaderMap;
+pub use self::utils::*;
 
-/// A trait for any object that will represent a header field and value.
-pub trait Header
-where
-    Self: IntoHeaderValue,
-{
+/// A trait for any object that already represents a valid header field and value.
+pub trait Header: IntoHeaderValue {
     /// Returns the name of the header field
     fn name() -> HeaderName;
 
@@ -37,170 +41,16 @@ where
     fn parse<T: HttpMessage>(msg: &T) -> Result<Self, ParseError>;
 }
 
-/// A trait for any object that can be Converted to a `HeaderValue`
-pub trait IntoHeaderValue: Sized {
-    /// The type returned in the event of a conversion error.
-    type Error: Into<HttpError>;
-
-    /// Try to convert value to a Header value.
-    fn try_into(self) -> Result<HeaderValue, Self::Error>;
-}
-
-impl IntoHeaderValue for HeaderValue {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        Ok(self)
-    }
-}
-
-impl<'a> IntoHeaderValue for &'a str {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        self.parse()
-    }
-}
-
-impl<'a> IntoHeaderValue for &'a [u8] {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::from_bytes(self)
-    }
-}
-
-impl IntoHeaderValue for Bytes {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::from_maybe_shared(self)
-    }
-}
-
-impl IntoHeaderValue for Vec<u8> {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::try_from(self)
-    }
-}
-
-impl IntoHeaderValue for String {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::try_from(self)
-    }
-}
-
-impl IntoHeaderValue for usize {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        let s = format!("{}", self);
-        HeaderValue::try_from(s)
-    }
-}
-
-impl IntoHeaderValue for u64 {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        let s = format!("{}", self);
-        HeaderValue::try_from(s)
-    }
-}
-
-impl IntoHeaderValue for Mime {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::try_from(format!("{}", self))
-    }
-}
-
-/// Represents supported types of content encodings
-#[derive(Copy, Clone, PartialEq, Debug)]
-pub enum ContentEncoding {
-    /// Automatically select encoding based on encoding negotiation
-    Auto,
-    /// A format using the Brotli algorithm
-    Br,
-    /// A format using the zlib structure with deflate algorithm
-    Deflate,
-    /// Gzip algorithm
-    Gzip,
-    /// Indicates the identity function (i.e. no compression, nor modification)
-    Identity,
-}
-
-impl ContentEncoding {
-    #[inline]
-    /// Is the content compressed?
-    pub fn is_compression(self) -> bool {
-        matches!(self, ContentEncoding::Identity | ContentEncoding::Auto)
-    }
-
-    #[inline]
-    /// Convert content encoding to string
-    pub fn as_str(self) -> &'static str {
-        match self {
-            ContentEncoding::Br => "br",
-            ContentEncoding::Gzip => "gzip",
-            ContentEncoding::Deflate => "deflate",
-            ContentEncoding::Identity | ContentEncoding::Auto => "identity",
-        }
-    }
-
-    #[inline]
-    /// default quality value
-    pub fn quality(self) -> f64 {
-        match self {
-            ContentEncoding::Br => 1.1,
-            ContentEncoding::Gzip => 1.0,
-            ContentEncoding::Deflate => 0.9,
-            ContentEncoding::Identity | ContentEncoding::Auto => 0.1,
-        }
-    }
-}
-
-impl<'a> From<&'a str> for ContentEncoding {
-    fn from(s: &'a str) -> ContentEncoding {
-        let s = s.trim();
-
-        if s.eq_ignore_ascii_case("br") {
-            ContentEncoding::Br
-        } else if s.eq_ignore_ascii_case("gzip") {
-            ContentEncoding::Gzip
-        } else if s.eq_ignore_ascii_case("deflate") {
-            ContentEncoding::Deflate
-        } else {
-            ContentEncoding::Identity
-        }
-    }
-}
-
-#[doc(hidden)]
+#[derive(Debug, Default)]
 pub(crate) struct Writer {
     buf: BytesMut,
 }
 
 impl Writer {
     fn new() -> Writer {
-        Writer {
-            buf: BytesMut::new(),
-        }
+        Writer::default()
     }
+
     fn take(&mut self) -> Bytes {
         self.buf.split().freeze()
     }
@@ -219,178 +69,15 @@ impl fmt::Write for Writer {
     }
 }
 
-#[inline]
-#[doc(hidden)]
-/// Reads a comma-delimited raw header into a Vec.
-pub fn from_comma_delimited<'a, I: Iterator<Item = &'a HeaderValue> + 'a, T: FromStr>(
-    all: I,
-) -> Result<Vec<T>, ParseError> {
-    let mut result = Vec::new();
-    for h in all {
-        let s = h.to_str().map_err(|_| ParseError::Header)?;
-        result.extend(
-            s.split(',')
-                .filter_map(|x| match x.trim() {
-                    "" => None,
-                    y => Some(y),
-                })
-                .filter_map(|x| x.trim().parse().ok()),
-        )
-    }
-    Ok(result)
-}
-
-#[inline]
-#[doc(hidden)]
-/// Reads a single string when parsing a header.
-pub fn from_one_raw_str<T: FromStr>(val: Option<&HeaderValue>) -> Result<T, ParseError> {
-    if let Some(line) = val {
-        let line = line.to_str().map_err(|_| ParseError::Header)?;
-        if !line.is_empty() {
-            return T::from_str(line).or(Err(ParseError::Header));
-        }
-    }
-    Err(ParseError::Header)
-}
-
-#[inline]
-#[doc(hidden)]
-/// Format an array into a comma-delimited string.
-pub fn fmt_comma_delimited<T>(f: &mut fmt::Formatter<'_>, parts: &[T]) -> fmt::Result
-where
-    T: fmt::Display,
-{
-    let mut iter = parts.iter();
-    if let Some(part) = iter.next() {
-        fmt::Display::fmt(part, f)?;
-    }
-    for part in iter {
-        f.write_str(", ")?;
-        fmt::Display::fmt(part, f)?;
-    }
-    Ok(())
-}
-
-// From hyper v0.11.27 src/header/parsing.rs
-
-/// The value part of an extended parameter consisting of three parts:
-/// the REQUIRED character set name (`charset`), the OPTIONAL language information (`language_tag`),
-/// and a character sequence representing the actual value (`value`), separated by single quote
-/// characters. It is defined in [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
-#[derive(Clone, Debug, PartialEq)]
-pub struct ExtendedValue {
-    /// The character set that is used to encode the `value` to a string.
-    pub charset: Charset,
-    /// The human language details of the `value`, if available.
-    pub language_tag: Option<LanguageTag>,
-    /// The parameter value, as expressed in octets.
-    pub value: Vec<u8>,
-}
-
-/// Parses extended header parameter values (`ext-value`), as defined in
-/// [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
-///
-/// Extended values are denoted by parameter names that end with `*`.
-///
-/// ## ABNF
-///
-/// ```text
-/// ext-value     = charset  "'" [ language ] "'" value-chars
-///               ; like RFC 2231's <extended-initial-value>
-///               ; (see [RFC2231], Section 7)
-///
-/// charset       = "UTF-8" / "ISO-8859-1" / mime-charset
-///
-/// mime-charset  = 1*mime-charsetc
-/// mime-charsetc = ALPHA / DIGIT
-///               / "!" / "#" / "$" / "%" / "&"
-///               / "+" / "-" / "^" / "_" / "`"
-///               / "{" / "}" / "~"
-///               ; as <mime-charset> in Section 2.3 of [RFC2978]
-///               ; except that the single quote is not included
-///               ; SHOULD be registered in the IANA charset registry
-///
-/// language      = <Language-Tag, defined in [RFC5646], Section 2.1>
-///
-/// value-chars   = *( pct-encoded / attr-char )
-///
-/// pct-encoded   = "%" HEXDIG HEXDIG
-///               ; see [RFC3986], Section 2.1
-///
-/// attr-char     = ALPHA / DIGIT
-///               / "!" / "#" / "$" / "&" / "+" / "-" / "."
-///               / "^" / "_" / "`" / "|" / "~"
-///               ; token except ( "*" / "'" / "%" )
-/// ```
-pub fn parse_extended_value(
-    val: &str,
-) -> Result<ExtendedValue, crate::error::ParseError> {
-    // Break into three pieces separated by the single-quote character
-    let mut parts = val.splitn(3, '\'');
-
-    // Interpret the first piece as a Charset
-    let charset: Charset = match parts.next() {
-        None => return Err(crate::error::ParseError::Header),
-        Some(n) => FromStr::from_str(n).map_err(|_| crate::error::ParseError::Header)?,
-    };
-
-    // Interpret the second piece as a language tag
-    let language_tag: Option<LanguageTag> = match parts.next() {
-        None => return Err(crate::error::ParseError::Header),
-        Some("") => None,
-        Some(s) => match s.parse() {
-            Ok(lt) => Some(lt),
-            Err(_) => return Err(crate::error::ParseError::Header),
-        },
-    };
-
-    // Interpret the third piece as a sequence of value characters
-    let value: Vec<u8> = match parts.next() {
-        None => return Err(crate::error::ParseError::Header),
-        Some(v) => percent_encoding::percent_decode(v.as_bytes()).collect(),
-    };
-
-    Ok(ExtendedValue {
-        value,
-        charset,
-        language_tag,
-    })
-}
-
-impl fmt::Display for ExtendedValue {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let encoded_value =
-            percent_encoding::percent_encode(&self.value[..], HTTP_VALUE);
-        if let Some(ref lang) = self.language_tag {
-            write!(f, "{}'{}'{}", self.charset, lang, encoded_value)
-        } else {
-            write!(f, "{}''{}", self.charset, encoded_value)
-        }
-    }
-}
-
-/// Percent encode a sequence of bytes with a character set defined in
-/// [https://tools.ietf.org/html/rfc5987#section-3.2][url]
-///
-/// [url]: https://tools.ietf.org/html/rfc5987#section-3.2
-pub fn http_percent_encode(f: &mut fmt::Formatter<'_>, bytes: &[u8]) -> fmt::Result {
-    let encoded = percent_encoding::percent_encode(bytes, HTTP_VALUE);
-    fmt::Display::fmt(&encoded, f)
-}
-
-/// Convert http::HeaderMap to a HeaderMap
+/// Convert `http::HeaderMap` to our `HeaderMap`.
 impl From<http::HeaderMap> for HeaderMap {
-    fn from(map: http::HeaderMap) -> HeaderMap {
-        let mut new_map = HeaderMap::with_capacity(map.capacity());
-        for (h, v) in map.iter() {
-            new_map.append(h.clone(), v.clone());
-        }
-        new_map
+    fn from(mut map: http::HeaderMap) -> HeaderMap {
+        HeaderMap::from_drain(map.drain())
     }
 }
 
-// This encode set is used for HTTP header values and is defined at
-// https://tools.ietf.org/html/rfc5987#section-3.2
+/// This encode set is used for HTTP header values and is defined at
+/// https://tools.ietf.org/html/rfc5987#section-3.2.
 pub(crate) const HTTP_VALUE: &AsciiSet = &CONTROLS
     .add(b' ')
     .add(b'"')
@@ -412,91 +99,3 @@ pub(crate) const HTTP_VALUE: &AsciiSet = &CONTROLS
     .add(b']')
     .add(b'{')
     .add(b'}');
-
-#[cfg(test)]
-mod tests {
-    use super::shared::Charset;
-    use super::{parse_extended_value, ExtendedValue};
-    use language_tags::LanguageTag;
-
-    #[test]
-    fn test_parse_extended_value_with_encoding_and_language_tag() {
-        let expected_language_tag = "en".parse::<LanguageTag>().unwrap();
-        // RFC 5987, Section 3.2.2
-        // Extended notation, using the Unicode character U+00A3 (POUND SIGN)
-        let result = parse_extended_value("iso-8859-1'en'%A3%20rates");
-        assert!(result.is_ok());
-        let extended_value = result.unwrap();
-        assert_eq!(Charset::Iso_8859_1, extended_value.charset);
-        assert!(extended_value.language_tag.is_some());
-        assert_eq!(expected_language_tag, extended_value.language_tag.unwrap());
-        assert_eq!(
-            vec![163, b' ', b'r', b'a', b't', b'e', b's'],
-            extended_value.value
-        );
-    }
-
-    #[test]
-    fn test_parse_extended_value_with_encoding() {
-        // RFC 5987, Section 3.2.2
-        // Extended notation, using the Unicode characters U+00A3 (POUND SIGN)
-        // and U+20AC (EURO SIGN)
-        let result = parse_extended_value("UTF-8''%c2%a3%20and%20%e2%82%ac%20rates");
-        assert!(result.is_ok());
-        let extended_value = result.unwrap();
-        assert_eq!(Charset::Ext("UTF-8".to_string()), extended_value.charset);
-        assert!(extended_value.language_tag.is_none());
-        assert_eq!(
-            vec![
-                194, 163, b' ', b'a', b'n', b'd', b' ', 226, 130, 172, b' ', b'r', b'a',
-                b't', b'e', b's',
-            ],
-            extended_value.value
-        );
-    }
-
-    #[test]
-    fn test_parse_extended_value_missing_language_tag_and_encoding() {
-        // From: https://greenbytes.de/tech/tc2231/#attwithfn2231quot2
-        let result = parse_extended_value("foo%20bar.html");
-        assert!(result.is_err());
-    }
-
-    #[test]
-    fn test_parse_extended_value_partially_formatted() {
-        let result = parse_extended_value("UTF-8'missing third part");
-        assert!(result.is_err());
-    }
-
-    #[test]
-    fn test_parse_extended_value_partially_formatted_blank() {
-        let result = parse_extended_value("blank second part'");
-        assert!(result.is_err());
-    }
-
-    #[test]
-    fn test_fmt_extended_value_with_encoding_and_language_tag() {
-        let extended_value = ExtendedValue {
-            charset: Charset::Iso_8859_1,
-            language_tag: Some("en".parse().expect("Could not parse language tag")),
-            value: vec![163, b' ', b'r', b'a', b't', b'e', b's'],
-        };
-        assert_eq!("ISO-8859-1'en'%A3%20rates", format!("{}", extended_value));
-    }
-
-    #[test]
-    fn test_fmt_extended_value_with_encoding() {
-        let extended_value = ExtendedValue {
-            charset: Charset::Ext("UTF-8".to_string()),
-            language_tag: None,
-            value: vec![
-                194, 163, b' ', b'a', b'n', b'd', b' ', 226, 130, 172, b' ', b'r', b'a',
-                b't', b'e', b's',
-            ],
-        };
-        assert_eq!(
-            "UTF-8''%C2%A3%20and%20%E2%82%AC%20rates",
-            format!("{}", extended_value)
-        );
-    }
-}
diff --git a/actix-http/src/header/shared/charset.rs b/actix-http/src/header/shared/charset.rs
index 00e7309d4..36bdbf7e2 100644
--- a/actix-http/src/header/shared/charset.rs
+++ b/actix-http/src/header/shared/charset.rs
@@ -7,9 +7,7 @@ use self::Charset::*;
 ///
 /// The string representation is normalized to upper case.
 ///
-/// See [http://www.iana.org/assignments/character-sets/character-sets.xhtml][url].
-///
-/// [url]: http://www.iana.org/assignments/character-sets/character-sets.xhtml
+/// See <http://www.iana.org/assignments/character-sets/character-sets.xhtml>.
 #[derive(Clone, Debug, PartialEq)]
 #[allow(non_camel_case_types)]
 pub enum Charset {
diff --git a/actix-http/src/header/shared/entity.rs b/actix-http/src/header/shared/entity.rs
index 3525a19c6..eb383cd6f 100644
--- a/actix-http/src/header/shared/entity.rs
+++ b/actix-http/src/header/shared/entity.rs
@@ -7,10 +7,12 @@ use crate::header::{HeaderValue, IntoHeaderValue, InvalidHeaderValue, Writer};
 /// 1. `%x21`, or
 /// 2. in the range `%x23` to `%x7E`, or
 /// 3. above `%x80`
+fn entity_validate_char(c: u8) -> bool {
+    c == 0x21 || (0x23..=0x7e).contains(&c) || (c >= 0x80)
+}
+
 fn check_slice_validity(slice: &str) -> bool {
-    slice
-        .bytes()
-        .all(|c| c == b'\x21' || (c >= b'\x23' && c <= b'\x7e') | (c >= b'\x80'))
+    slice.bytes().all(entity_validate_char)
 }
 
 /// An entity tag, defined in [RFC7232](https://tools.ietf.org/html/rfc7232#section-2.3)
@@ -159,7 +161,7 @@ impl FromStr for EntityTag {
 impl IntoHeaderValue for EntityTag {
     type Error = InvalidHeaderValue;
 
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
         let mut wrt = Writer::new();
         write!(wrt, "{}", self).unwrap();
         HeaderValue::from_maybe_shared(wrt.take())
diff --git a/actix-http/src/header/shared/extended.rs b/actix-http/src/header/shared/extended.rs
new file mode 100644
index 000000000..6bdcb7922
--- /dev/null
+++ b/actix-http/src/header/shared/extended.rs
@@ -0,0 +1,193 @@
+use std::{fmt, str::FromStr};
+
+use language_tags::LanguageTag;
+
+use crate::header::{Charset, HTTP_VALUE};
+
+// From hyper v0.11.27 src/header/parsing.rs
+
+/// The value part of an extended parameter consisting of three parts:
+/// - The REQUIRED character set name (`charset`).
+/// - The OPTIONAL language information (`language_tag`).
+/// - A character sequence representing the actual value (`value`), separated by single quotes.
+///
+/// It is defined in [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
+#[derive(Clone, Debug, PartialEq)]
+pub struct ExtendedValue {
+    /// The character set that is used to encode the `value` to a string.
+    pub charset: Charset,
+
+    /// The human language details of the `value`, if available.
+    pub language_tag: Option<LanguageTag>,
+
+    /// The parameter value, as expressed in octets.
+    pub value: Vec<u8>,
+}
+
+/// Parses extended header parameter values (`ext-value`), as defined in
+/// [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
+///
+/// Extended values are denoted by parameter names that end with `*`.
+///
+/// ## ABNF
+///
+/// ```text
+/// ext-value     = charset  "'" [ language ] "'" value-chars
+///               ; like RFC 2231's <extended-initial-value>
+///               ; (see [RFC2231], Section 7)
+///
+/// charset       = "UTF-8" / "ISO-8859-1" / mime-charset
+///
+/// mime-charset  = 1*mime-charsetc
+/// mime-charsetc = ALPHA / DIGIT
+///               / "!" / "#" / "$" / "%" / "&"
+///               / "+" / "-" / "^" / "_" / "`"
+///               / "{" / "}" / "~"
+///               ; as <mime-charset> in Section 2.3 of [RFC2978]
+///               ; except that the single quote is not included
+///               ; SHOULD be registered in the IANA charset registry
+///
+/// language      = <Language-Tag, defined in [RFC5646], Section 2.1>
+///
+/// value-chars   = *( pct-encoded / attr-char )
+///
+/// pct-encoded   = "%" HEXDIG HEXDIG
+///               ; see [RFC3986], Section 2.1
+///
+/// attr-char     = ALPHA / DIGIT
+///               / "!" / "#" / "$" / "&" / "+" / "-" / "."
+///               / "^" / "_" / "`" / "|" / "~"
+///               ; token except ( "*" / "'" / "%" )
+/// ```
+pub fn parse_extended_value(
+    val: &str,
+) -> Result<ExtendedValue, crate::error::ParseError> {
+    // Break into three pieces separated by the single-quote character
+    let mut parts = val.splitn(3, '\'');
+
+    // Interpret the first piece as a Charset
+    let charset: Charset = match parts.next() {
+        None => return Err(crate::error::ParseError::Header),
+        Some(n) => FromStr::from_str(n).map_err(|_| crate::error::ParseError::Header)?,
+    };
+
+    // Interpret the second piece as a language tag
+    let language_tag: Option<LanguageTag> = match parts.next() {
+        None => return Err(crate::error::ParseError::Header),
+        Some("") => None,
+        Some(s) => match s.parse() {
+            Ok(lt) => Some(lt),
+            Err(_) => return Err(crate::error::ParseError::Header),
+        },
+    };
+
+    // Interpret the third piece as a sequence of value characters
+    let value: Vec<u8> = match parts.next() {
+        None => return Err(crate::error::ParseError::Header),
+        Some(v) => percent_encoding::percent_decode(v.as_bytes()).collect(),
+    };
+
+    Ok(ExtendedValue {
+        value,
+        charset,
+        language_tag,
+    })
+}
+
+impl fmt::Display for ExtendedValue {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let encoded_value =
+            percent_encoding::percent_encode(&self.value[..], HTTP_VALUE);
+        if let Some(ref lang) = self.language_tag {
+            write!(f, "{}'{}'{}", self.charset, lang, encoded_value)
+        } else {
+            write!(f, "{}''{}", self.charset, encoded_value)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_extended_value_with_encoding_and_language_tag() {
+        let expected_language_tag = "en".parse::<LanguageTag>().unwrap();
+        // RFC 5987, Section 3.2.2
+        // Extended notation, using the Unicode character U+00A3 (POUND SIGN)
+        let result = parse_extended_value("iso-8859-1'en'%A3%20rates");
+        assert!(result.is_ok());
+        let extended_value = result.unwrap();
+        assert_eq!(Charset::Iso_8859_1, extended_value.charset);
+        assert!(extended_value.language_tag.is_some());
+        assert_eq!(expected_language_tag, extended_value.language_tag.unwrap());
+        assert_eq!(
+            vec![163, b' ', b'r', b'a', b't', b'e', b's'],
+            extended_value.value
+        );
+    }
+
+    #[test]
+    fn test_parse_extended_value_with_encoding() {
+        // RFC 5987, Section 3.2.2
+        // Extended notation, using the Unicode characters U+00A3 (POUND SIGN)
+        // and U+20AC (EURO SIGN)
+        let result = parse_extended_value("UTF-8''%c2%a3%20and%20%e2%82%ac%20rates");
+        assert!(result.is_ok());
+        let extended_value = result.unwrap();
+        assert_eq!(Charset::Ext("UTF-8".to_string()), extended_value.charset);
+        assert!(extended_value.language_tag.is_none());
+        assert_eq!(
+            vec![
+                194, 163, b' ', b'a', b'n', b'd', b' ', 226, 130, 172, b' ', b'r', b'a',
+                b't', b'e', b's',
+            ],
+            extended_value.value
+        );
+    }
+
+    #[test]
+    fn test_parse_extended_value_missing_language_tag_and_encoding() {
+        // From: https://greenbytes.de/tech/tc2231/#attwithfn2231quot2
+        let result = parse_extended_value("foo%20bar.html");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_parse_extended_value_partially_formatted() {
+        let result = parse_extended_value("UTF-8'missing third part");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_parse_extended_value_partially_formatted_blank() {
+        let result = parse_extended_value("blank second part'");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_fmt_extended_value_with_encoding_and_language_tag() {
+        let extended_value = ExtendedValue {
+            charset: Charset::Iso_8859_1,
+            language_tag: Some("en".parse().expect("Could not parse language tag")),
+            value: vec![163, b' ', b'r', b'a', b't', b'e', b's'],
+        };
+        assert_eq!("ISO-8859-1'en'%A3%20rates", format!("{}", extended_value));
+    }
+
+    #[test]
+    fn test_fmt_extended_value_with_encoding() {
+        let extended_value = ExtendedValue {
+            charset: Charset::Ext("UTF-8".to_string()),
+            language_tag: None,
+            value: vec![
+                194, 163, b' ', b'a', b'n', b'd', b' ', 226, 130, 172, b' ', b'r', b'a',
+                b't', b'e', b's',
+            ],
+        };
+        assert_eq!(
+            "UTF-8''%C2%A3%20and%20%E2%82%AC%20rates",
+            format!("{}", extended_value)
+        );
+    }
+}
diff --git a/actix-http/src/header/shared/httpdate.rs b/actix-http/src/header/shared/httpdate.rs
index 81caf6d53..72a225589 100644
--- a/actix-http/src/header/shared/httpdate.rs
+++ b/actix-http/src/header/shared/httpdate.rs
@@ -3,7 +3,8 @@ use std::io::Write;
 use std::str::FromStr;
 use std::time::{SystemTime, UNIX_EPOCH};
 
-use bytes::{buf::BufMutExt, BytesMut};
+use bytes::buf::BufMut;
+use bytes::BytesMut;
 use http::header::{HeaderValue, InvalidHeaderValue};
 use time::{offset, OffsetDateTime, PrimitiveDateTime};
 
@@ -47,7 +48,7 @@ impl From<SystemTime> for HttpDate {
 impl IntoHeaderValue for HttpDate {
     type Error = InvalidHeaderValue;
 
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
         let mut wrt = BytesMut::with_capacity(29).writer();
         write!(
             wrt,
diff --git a/actix-http/src/header/shared/mod.rs b/actix-http/src/header/shared/mod.rs
index f2bc91634..72161e46b 100644
--- a/actix-http/src/header/shared/mod.rs
+++ b/actix-http/src/header/shared/mod.rs
@@ -1,14 +1,16 @@
-//! Copied for `hyper::header::shared`;
-
-pub use self::charset::Charset;
-pub use self::encoding::Encoding;
-pub use self::entity::EntityTag;
-pub use self::httpdate::HttpDate;
-pub use self::quality_item::{q, qitem, Quality, QualityItem};
-pub use language_tags::LanguageTag;
+//! Originally taken from `hyper::header::shared`.
 
 mod charset;
 mod encoding;
 mod entity;
+mod extended;
 mod httpdate;
 mod quality_item;
+
+pub use self::charset::Charset;
+pub use self::encoding::Encoding;
+pub use self::entity::EntityTag;
+pub use self::extended::{parse_extended_value, ExtendedValue};
+pub use self::httpdate::HttpDate;
+pub use self::quality_item::{q, qitem, Quality, QualityItem};
+pub use language_tags::LanguageTag;
diff --git a/actix-http/src/header/shared/quality_item.rs b/actix-http/src/header/shared/quality_item.rs
index 98230dec1..01a3b988a 100644
--- a/actix-http/src/header/shared/quality_item.rs
+++ b/actix-http/src/header/shared/quality_item.rs
@@ -1,10 +1,17 @@
-use std::{cmp, fmt, str};
+use std::{
+    cmp,
+    convert::{TryFrom, TryInto},
+    fmt, str,
+};
 
-use self::internal::IntoQuality;
+use derive_more::{Display, Error};
+
+const MAX_QUALITY: u16 = 1000;
+const MAX_FLOAT_QUALITY: f32 = 1.0;
 
 /// Represents a quality used in quality values.
 ///
-/// Can be created with the `q` function.
+/// Can be created with the [`q`] function.
 ///
 /// # Implementation notes
 ///
@@ -18,12 +25,54 @@ use self::internal::IntoQuality;
 ///
 /// [RFC7231 Section 5.3.1](https://tools.ietf.org/html/rfc7231#section-5.3.1)
 /// gives more information on quality values in HTTP header fields.
-#[derive(Copy, Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Quality(u16);
 
+impl Quality {
+    /// # Panics
+    /// Panics in debug mode when value is not in the range 0.0 <= n <= 1.0.
+    fn from_f32(value: f32) -> Self {
+        // Check that `value` is within range should be done before calling this method.
+        // Just in case, this debug_assert should catch if we were forgetful.
+        debug_assert!(
+            (0.0f32..=1.0f32).contains(&value),
+            "q value must be between 0.0 and 1.0"
+        );
+
+        Quality((value * MAX_QUALITY as f32) as u16)
+    }
+}
+
 impl Default for Quality {
     fn default() -> Quality {
-        Quality(1000)
+        Quality(MAX_QUALITY)
+    }
+}
+
+#[derive(Debug, Clone, Display, Error)]
+pub struct QualityOutOfBounds;
+
+impl TryFrom<u16> for Quality {
+    type Error = QualityOutOfBounds;
+
+    fn try_from(value: u16) -> Result<Self, Self::Error> {
+        if (0..=MAX_QUALITY).contains(&value) {
+            Ok(Quality(value))
+        } else {
+            Err(QualityOutOfBounds)
+        }
+    }
+}
+
+impl TryFrom<f32> for Quality {
+    type Error = QualityOutOfBounds;
+
+    fn try_from(value: f32) -> Result<Self, Self::Error> {
+        if (0.0..=MAX_FLOAT_QUALITY).contains(&value) {
+            Ok(Quality::from_f32(value))
+        } else {
+            Err(QualityOutOfBounds)
+        }
     }
 }
 
@@ -55,8 +104,9 @@ impl<T: PartialEq> cmp::PartialOrd for QualityItem<T> {
 impl<T: fmt::Display> fmt::Display for QualityItem<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(&self.item, f)?;
+
         match self.quality.0 {
-            1000 => Ok(()),
+            MAX_QUALITY => Ok(()),
             0 => f.write_str("; q=0"),
             x => write!(f, "; q=0.{}", format!("{:03}", x).trim_end_matches('0')),
         }
@@ -66,105 +116,79 @@ impl<T: fmt::Display> fmt::Display for QualityItem<T> {
 impl<T: str::FromStr> str::FromStr for QualityItem<T> {
     type Err = crate::error::ParseError;
 
-    fn from_str(s: &str) -> Result<QualityItem<T>, crate::error::ParseError> {
-        if !s.is_ascii() {
+    fn from_str(qitem_str: &str) -> Result<QualityItem<T>, crate::error::ParseError> {
+        if !qitem_str.is_ascii() {
             return Err(crate::error::ParseError::Header);
         }
+
         // Set defaults used if parsing fails.
-        let mut raw_item = s;
+        let mut raw_item = qitem_str;
         let mut quality = 1f32;
 
-        let parts: Vec<&str> = s.rsplitn(2, ';').map(|x| x.trim()).collect();
+        let parts: Vec<_> = qitem_str.rsplitn(2, ';').map(str::trim).collect();
+
         if parts.len() == 2 {
+            // example for item with q-factor:
+            //
+            // gzip; q=0.65
+            //       ^^^^^^  parts[0]
+            //       ^^      start
+            //         ^^^^  q_val
+            // ^^^^          parts[1]
+
             if parts[0].len() < 2 {
+                // Can't possibly be an attribute since an attribute needs at least a name followed
+                // by an equals sign. And bare identifiers are forbidden.
                 return Err(crate::error::ParseError::Header);
             }
+
             let start = &parts[0][0..2];
+
             if start == "q=" || start == "Q=" {
-                let q_part = &parts[0][2..parts[0].len()];
-                if q_part.len() > 5 {
+                let q_val = &parts[0][2..];
+                if q_val.len() > 5 {
+                    // longer than 5 indicates an over-precise q-factor
                     return Err(crate::error::ParseError::Header);
                 }
-                match q_part.parse::<f32>() {
-                    Ok(q_value) => {
-                        if 0f32 <= q_value && q_value <= 1f32 {
-                            quality = q_value;
-                            raw_item = parts[1];
-                        } else {
-                            return Err(crate::error::ParseError::Header);
-                        }
-                    }
-                    Err(_) => return Err(crate::error::ParseError::Header),
+
+                let q_value = q_val
+                    .parse::<f32>()
+                    .map_err(|_| crate::error::ParseError::Header)?;
+
+                if (0f32..=1f32).contains(&q_value) {
+                    quality = q_value;
+                    raw_item = parts[1];
+                } else {
+                    return Err(crate::error::ParseError::Header);
                 }
             }
         }
-        match raw_item.parse::<T>() {
-            // we already checked above that the quality is within range
-            Ok(item) => Ok(QualityItem::new(item, from_f32(quality))),
-            Err(_) => Err(crate::error::ParseError::Header),
-        }
-    }
-}
 
-#[inline]
-fn from_f32(f: f32) -> Quality {
-    // this function is only used internally. A check that `f` is within range
-    // should be done before calling this method. Just in case, this
-    // debug_assert should catch if we were forgetful
-    debug_assert!(
-        f >= 0f32 && f <= 1f32,
-        "q value must be between 0.0 and 1.0"
-    );
-    Quality((f * 1000f32) as u16)
+        let item = raw_item
+            .parse::<T>()
+            .map_err(|_| crate::error::ParseError::Header)?;
+
+        // we already checked above that the quality is within range
+        Ok(QualityItem::new(item, Quality::from_f32(quality)))
+    }
 }
 
 /// Convenience function to wrap a value in a `QualityItem`
 /// Sets `q` to the default 1.0
 pub fn qitem<T>(item: T) -> QualityItem<T> {
-    QualityItem::new(item, Default::default())
+    QualityItem::new(item, Quality::default())
 }
 
 /// Convenience function to create a `Quality` from a float or integer.
 ///
 /// Implemented for `u16` and `f32`. Panics if value is out of range.
-pub fn q<T: IntoQuality>(val: T) -> Quality {
-    val.into_quality()
-}
-
-mod internal {
-    use super::Quality;
-
-    // TryFrom is probably better, but it's not stable. For now, we want to
-    // keep the functionality of the `q` function, while allowing it to be
-    // generic over `f32` and `u16`.
-    //
-    // `q` would panic before, so keep that behavior. `TryFrom` can be
-    // introduced later for a non-panicking conversion.
-
-    pub trait IntoQuality: Sealed + Sized {
-        fn into_quality(self) -> Quality;
-    }
-
-    impl IntoQuality for f32 {
-        fn into_quality(self) -> Quality {
-            assert!(
-                self >= 0f32 && self <= 1f32,
-                "float must be between 0.0 and 1.0"
-            );
-            super::from_f32(self)
-        }
-    }
-
-    impl IntoQuality for u16 {
-        fn into_quality(self) -> Quality {
-            assert!(self <= 1000, "u16 must be between 0 and 1000");
-            Quality(self)
-        }
-    }
-
-    pub trait Sealed {}
-    impl Sealed for u16 {}
-    impl Sealed for f32 {}
+pub fn q<T>(val: T) -> Quality
+where
+    T: TryInto<Quality>,
+    T::Error: fmt::Debug,
+{
+    // TODO: on next breaking change, handle unwrap differently
+    val.try_into().unwrap()
 }
 
 #[cfg(test)]
@@ -270,15 +294,13 @@ mod tests {
     }
 
     #[test]
-    #[should_panic] // FIXME - 32-bit msvc unwinding broken
-    #[cfg_attr(all(target_arch = "x86", target_env = "msvc"), ignore)]
+    #[should_panic]
     fn test_quality_invalid() {
         q(-1.0);
     }
 
     #[test]
-    #[should_panic] // FIXME - 32-bit msvc unwinding broken
-    #[cfg_attr(all(target_arch = "x86", target_env = "msvc"), ignore)]
+    #[should_panic]
     fn test_quality_invalid2() {
         q(2.0);
     }
diff --git a/actix-http/src/header/utils.rs b/actix-http/src/header/utils.rs
new file mode 100644
index 000000000..e232d462f
--- /dev/null
+++ b/actix-http/src/header/utils.rs
@@ -0,0 +1,63 @@
+use std::{fmt, str::FromStr};
+
+use http::HeaderValue;
+
+use crate::{error::ParseError, header::HTTP_VALUE};
+
+/// Reads a comma-delimited raw header into a Vec.
+#[inline]
+pub fn from_comma_delimited<'a, I, T>(all: I) -> Result<Vec<T>, ParseError>
+where
+    I: Iterator<Item = &'a HeaderValue> + 'a,
+    T: FromStr,
+{
+    let mut result = Vec::new();
+    for h in all {
+        let s = h.to_str().map_err(|_| ParseError::Header)?;
+        result.extend(
+            s.split(',')
+                .filter_map(|x| match x.trim() {
+                    "" => None,
+                    y => Some(y),
+                })
+                .filter_map(|x| x.trim().parse().ok()),
+        )
+    }
+    Ok(result)
+}
+
+/// Reads a single string when parsing a header.
+#[inline]
+pub fn from_one_raw_str<T: FromStr>(val: Option<&HeaderValue>) -> Result<T, ParseError> {
+    if let Some(line) = val {
+        let line = line.to_str().map_err(|_| ParseError::Header)?;
+        if !line.is_empty() {
+            return T::from_str(line).or(Err(ParseError::Header));
+        }
+    }
+    Err(ParseError::Header)
+}
+
+/// Format an array into a comma-delimited string.
+#[inline]
+pub fn fmt_comma_delimited<T>(f: &mut fmt::Formatter<'_>, parts: &[T]) -> fmt::Result
+where
+    T: fmt::Display,
+{
+    let mut iter = parts.iter();
+    if let Some(part) = iter.next() {
+        fmt::Display::fmt(part, f)?;
+    }
+    for part in iter {
+        f.write_str(", ")?;
+        fmt::Display::fmt(part, f)?;
+    }
+    Ok(())
+}
+
+/// Percent encode a sequence of bytes with a character set defined in
+/// <https://tools.ietf.org/html/rfc5987#section-3.2>
+pub fn http_percent_encode(f: &mut fmt::Formatter<'_>, bytes: &[u8]) -> fmt::Result {
+    let encoded = percent_encoding::percent_encode(bytes, HTTP_VALUE);
+    fmt::Display::fmt(&encoded, f)
+}
diff --git a/actix-http/src/helpers.rs b/actix-http/src/helpers.rs
index bbf358b66..13195f7db 100644
--- a/actix-http/src/helpers.rs
+++ b/actix-http/src/helpers.rs
@@ -3,8 +3,6 @@ use std::io;
 use bytes::{BufMut, BytesMut};
 use http::Version;
 
-use crate::extensions::Extensions;
-
 const DIGITS_START: u8 = b'0';
 
 pub(crate) fn write_status_line(version: Version, n: u16, bytes: &mut BytesMut) {
@@ -50,23 +48,12 @@ impl<'a> io::Write for Writer<'a> {
         self.0.extend_from_slice(buf);
         Ok(buf.len())
     }
+
     fn flush(&mut self) -> io::Result<()> {
         Ok(())
     }
 }
 
-pub(crate) trait DataFactory {
-    fn set(&self, ext: &mut Extensions);
-}
-
-pub(crate) struct Data<T>(pub(crate) T);
-
-impl<T: Clone + 'static> DataFactory for Data<T> {
-    fn set(&self, ext: &mut Extensions) {
-        ext.insert(self.0.clone())
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use std::str::from_utf8;
diff --git a/actix-http/src/http_codes.rs b/actix-http/src/http_codes.rs
new file mode 100644
index 000000000..688a08be5
--- /dev/null
+++ b/actix-http/src/http_codes.rs
@@ -0,0 +1,101 @@
+//! Status code based HTTP response builders.
+
+#![allow(non_upper_case_globals)]
+
+use http::StatusCode;
+
+use crate::response::{Response, ResponseBuilder};
+
+macro_rules! static_resp {
+    ($name:ident, $status:expr) => {
+        #[allow(non_snake_case, missing_docs)]
+        pub fn $name() -> ResponseBuilder {
+            ResponseBuilder::new($status)
+        }
+    };
+}
+
+impl Response {
+    static_resp!(Continue, StatusCode::CONTINUE);
+    static_resp!(SwitchingProtocols, StatusCode::SWITCHING_PROTOCOLS);
+    static_resp!(Processing, StatusCode::PROCESSING);
+
+    static_resp!(Ok, StatusCode::OK);
+    static_resp!(Created, StatusCode::CREATED);
+    static_resp!(Accepted, StatusCode::ACCEPTED);
+    static_resp!(
+        NonAuthoritativeInformation,
+        StatusCode::NON_AUTHORITATIVE_INFORMATION
+    );
+
+    static_resp!(NoContent, StatusCode::NO_CONTENT);
+    static_resp!(ResetContent, StatusCode::RESET_CONTENT);
+    static_resp!(PartialContent, StatusCode::PARTIAL_CONTENT);
+    static_resp!(MultiStatus, StatusCode::MULTI_STATUS);
+    static_resp!(AlreadyReported, StatusCode::ALREADY_REPORTED);
+
+    static_resp!(MultipleChoices, StatusCode::MULTIPLE_CHOICES);
+    static_resp!(MovedPermanently, StatusCode::MOVED_PERMANENTLY);
+    static_resp!(Found, StatusCode::FOUND);
+    static_resp!(SeeOther, StatusCode::SEE_OTHER);
+    static_resp!(NotModified, StatusCode::NOT_MODIFIED);
+    static_resp!(UseProxy, StatusCode::USE_PROXY);
+    static_resp!(TemporaryRedirect, StatusCode::TEMPORARY_REDIRECT);
+    static_resp!(PermanentRedirect, StatusCode::PERMANENT_REDIRECT);
+
+    static_resp!(BadRequest, StatusCode::BAD_REQUEST);
+    static_resp!(NotFound, StatusCode::NOT_FOUND);
+    static_resp!(Unauthorized, StatusCode::UNAUTHORIZED);
+    static_resp!(PaymentRequired, StatusCode::PAYMENT_REQUIRED);
+    static_resp!(Forbidden, StatusCode::FORBIDDEN);
+    static_resp!(MethodNotAllowed, StatusCode::METHOD_NOT_ALLOWED);
+    static_resp!(NotAcceptable, StatusCode::NOT_ACCEPTABLE);
+    static_resp!(
+        ProxyAuthenticationRequired,
+        StatusCode::PROXY_AUTHENTICATION_REQUIRED
+    );
+    static_resp!(RequestTimeout, StatusCode::REQUEST_TIMEOUT);
+    static_resp!(Conflict, StatusCode::CONFLICT);
+    static_resp!(Gone, StatusCode::GONE);
+    static_resp!(LengthRequired, StatusCode::LENGTH_REQUIRED);
+    static_resp!(PreconditionFailed, StatusCode::PRECONDITION_FAILED);
+    static_resp!(PreconditionRequired, StatusCode::PRECONDITION_REQUIRED);
+    static_resp!(PayloadTooLarge, StatusCode::PAYLOAD_TOO_LARGE);
+    static_resp!(UriTooLong, StatusCode::URI_TOO_LONG);
+    static_resp!(UnsupportedMediaType, StatusCode::UNSUPPORTED_MEDIA_TYPE);
+    static_resp!(RangeNotSatisfiable, StatusCode::RANGE_NOT_SATISFIABLE);
+    static_resp!(ExpectationFailed, StatusCode::EXPECTATION_FAILED);
+    static_resp!(UnprocessableEntity, StatusCode::UNPROCESSABLE_ENTITY);
+    static_resp!(TooManyRequests, StatusCode::TOO_MANY_REQUESTS);
+    static_resp!(
+        RequestHeaderFieldsTooLarge,
+        StatusCode::REQUEST_HEADER_FIELDS_TOO_LARGE
+    );
+    static_resp!(
+        UnavailableForLegalReasons,
+        StatusCode::UNAVAILABLE_FOR_LEGAL_REASONS
+    );
+
+    static_resp!(InternalServerError, StatusCode::INTERNAL_SERVER_ERROR);
+    static_resp!(NotImplemented, StatusCode::NOT_IMPLEMENTED);
+    static_resp!(BadGateway, StatusCode::BAD_GATEWAY);
+    static_resp!(ServiceUnavailable, StatusCode::SERVICE_UNAVAILABLE);
+    static_resp!(GatewayTimeout, StatusCode::GATEWAY_TIMEOUT);
+    static_resp!(VersionNotSupported, StatusCode::HTTP_VERSION_NOT_SUPPORTED);
+    static_resp!(VariantAlsoNegotiates, StatusCode::VARIANT_ALSO_NEGOTIATES);
+    static_resp!(InsufficientStorage, StatusCode::INSUFFICIENT_STORAGE);
+    static_resp!(LoopDetected, StatusCode::LOOP_DETECTED);
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::body::Body;
+    use crate::response::Response;
+    use http::StatusCode;
+
+    #[test]
+    fn test_build() {
+        let resp = Response::Ok().body(Body::Empty);
+        assert_eq!(resp.status(), StatusCode::OK);
+    }
+}
diff --git a/actix-http/src/httpmessage.rs b/actix-http/src/http_message.rs
similarity index 77%
rename from actix-http/src/httpmessage.rs
rename to actix-http/src/http_message.rs
index 471fbbcdc..b1f04e50d 100644
--- a/actix-http/src/httpmessage.rs
+++ b/actix-http/src/http_message.rs
@@ -5,15 +5,17 @@ use encoding_rs::{Encoding, UTF_8};
 use http::header;
 use mime::Mime;
 
-use crate::cookie::Cookie;
-use crate::error::{ContentTypeError, CookieParseError, ParseError};
+use crate::error::{ContentTypeError, ParseError};
 use crate::extensions::Extensions;
 use crate::header::{Header, HeaderMap};
 use crate::payload::Payload;
+#[cfg(feature = "cookies")]
+use crate::{cookie::Cookie, error::CookieParseError};
 
+#[cfg(feature = "cookies")]
 struct Cookies(Vec<Cookie<'static>>);
 
-/// Trait that implements general purpose operations on http messages
+/// Trait that implements general purpose operations on HTTP messages.
 pub trait HttpMessage: Sized {
     /// Type of message payload stream
     type Stream;
@@ -30,8 +32,8 @@ pub trait HttpMessage: Sized {
     /// Mutable reference to a the request's extensions container
     fn extensions_mut(&self) -> RefMut<'_, Extensions>;
 
+    /// Get a header.
     #[doc(hidden)]
-    /// Get a header
     fn get_header<H: Header>(&self) -> Option<H>
     where
         Self: Sized,
@@ -43,8 +45,8 @@ pub trait HttpMessage: Sized {
         }
     }
 
-    /// Read the request content type. If request does not contain
-    /// *Content-Type* header, empty str get returned.
+    /// Read the request content type. If request did not contain a *Content-Type* header, an empty
+    /// string is returned.
     fn content_type(&self) -> &str {
         if let Some(content_type) = self.headers().get(header::CONTENT_TYPE) {
             if let Ok(content_type) = content_type.to_str() {
@@ -90,7 +92,7 @@ pub trait HttpMessage: Sized {
         Ok(None)
     }
 
-    /// Check if request has chunked transfer encoding
+    /// Check if request has chunked transfer encoding.
     fn chunked(&self) -> Result<bool, ParseError> {
         if let Some(encodings) = self.headers().get(header::TRANSFER_ENCODING) {
             if let Ok(s) = encodings.to_str() {
@@ -104,7 +106,7 @@ pub trait HttpMessage: Sized {
     }
 
     /// Load request cookies.
-    #[inline]
+    #[cfg(feature = "cookies")]
     fn cookies(&self) -> Result<Ref<'_, Vec<Cookie<'static>>>, CookieParseError> {
         if self.extensions().get::<Cookies>().is_none() {
             let mut cookies = Vec::new();
@@ -119,12 +121,14 @@ pub trait HttpMessage: Sized {
             }
             self.extensions_mut().insert(Cookies(cookies));
         }
+
         Ok(Ref::map(self.extensions(), |ext| {
             &ext.get::<Cookies>().unwrap().0
         }))
     }
 
     /// Return request cookie.
+    #[cfg(feature = "cookies")]
     fn cookie(&self, name: &str) -> Option<Cookie<'static>> {
         if let Ok(cookies) = self.cookies() {
             for cookie in cookies.iter() {
@@ -173,11 +177,13 @@ mod tests {
 
     #[test]
     fn test_content_type() {
-        let req = TestRequest::with_header("content-type", "text/plain").finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "text/plain"))
+            .finish();
         assert_eq!(req.content_type(), "text/plain");
-        let req =
-            TestRequest::with_header("content-type", "application/json; charset=utf=8")
-                .finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json; charset=utf=8"))
+            .finish();
         assert_eq!(req.content_type(), "application/json");
         let req = TestRequest::default().finish();
         assert_eq!(req.content_type(), "");
@@ -185,13 +191,15 @@ mod tests {
 
     #[test]
     fn test_mime_type() {
-        let req = TestRequest::with_header("content-type", "application/json").finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json"))
+            .finish();
         assert_eq!(req.mime_type().unwrap(), Some(mime::APPLICATION_JSON));
         let req = TestRequest::default().finish();
         assert_eq!(req.mime_type().unwrap(), None);
-        let req =
-            TestRequest::with_header("content-type", "application/json; charset=utf-8")
-                .finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json; charset=utf-8"))
+            .finish();
         let mt = req.mime_type().unwrap().unwrap();
         assert_eq!(mt.get_param(mime::CHARSET), Some(mime::UTF_8));
         assert_eq!(mt.type_(), mime::APPLICATION);
@@ -200,11 +208,9 @@ mod tests {
 
     #[test]
     fn test_mime_type_error() {
-        let req = TestRequest::with_header(
-            "content-type",
-            "applicationadfadsfasdflknadsfklnadsfjson",
-        )
-        .finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "applicationadfadsfasdflknadsfklnadsfjson"))
+            .finish();
         assert_eq!(Err(ContentTypeError::ParseError), req.mime_type());
     }
 
@@ -213,27 +219,27 @@ mod tests {
         let req = TestRequest::default().finish();
         assert_eq!(UTF_8.name(), req.encoding().unwrap().name());
 
-        let req = TestRequest::with_header("content-type", "application/json").finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json"))
+            .finish();
         assert_eq!(UTF_8.name(), req.encoding().unwrap().name());
 
-        let req = TestRequest::with_header(
-            "content-type",
-            "application/json; charset=ISO-8859-2",
-        )
-        .finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json; charset=ISO-8859-2"))
+            .finish();
         assert_eq!(ISO_8859_2, req.encoding().unwrap());
     }
 
     #[test]
     fn test_encoding_error() {
-        let req = TestRequest::with_header("content-type", "applicatjson").finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "applicatjson"))
+            .finish();
         assert_eq!(Some(ContentTypeError::ParseError), req.encoding().err());
 
-        let req = TestRequest::with_header(
-            "content-type",
-            "application/json; charset=kkkttktk",
-        )
-        .finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json; charset=kkkttktk"))
+            .finish();
         assert_eq!(
             Some(ContentTypeError::UnknownEncoding),
             req.encoding().err()
@@ -245,15 +251,16 @@ mod tests {
         let req = TestRequest::default().finish();
         assert!(!req.chunked().unwrap());
 
-        let req =
-            TestRequest::with_header(header::TRANSFER_ENCODING, "chunked").finish();
+        let req = TestRequest::default()
+            .insert_header((header::TRANSFER_ENCODING, "chunked"))
+            .finish();
         assert!(req.chunked().unwrap());
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::TRANSFER_ENCODING,
                 Bytes::from_static(b"some va\xadscc\xacas0xsdasdlue"),
-            )
+            ))
             .finish();
         assert!(req.chunked().is_err());
     }
diff --git a/actix-http/src/httpcodes.rs b/actix-http/src/httpcodes.rs
deleted file mode 100644
index 0c7f23fc8..000000000
--- a/actix-http/src/httpcodes.rs
+++ /dev/null
@@ -1,87 +0,0 @@
-//! Basic http responses
-#![allow(non_upper_case_globals)]
-use http::StatusCode;
-
-use crate::response::{Response, ResponseBuilder};
-
-macro_rules! STATIC_RESP {
-    ($name:ident, $status:expr) => {
-        #[allow(non_snake_case, missing_docs)]
-        pub fn $name() -> ResponseBuilder {
-            ResponseBuilder::new($status)
-        }
-    };
-}
-
-impl Response {
-    STATIC_RESP!(Ok, StatusCode::OK);
-    STATIC_RESP!(Created, StatusCode::CREATED);
-    STATIC_RESP!(Accepted, StatusCode::ACCEPTED);
-    STATIC_RESP!(
-        NonAuthoritativeInformation,
-        StatusCode::NON_AUTHORITATIVE_INFORMATION
-    );
-
-    STATIC_RESP!(NoContent, StatusCode::NO_CONTENT);
-    STATIC_RESP!(ResetContent, StatusCode::RESET_CONTENT);
-    STATIC_RESP!(PartialContent, StatusCode::PARTIAL_CONTENT);
-    STATIC_RESP!(MultiStatus, StatusCode::MULTI_STATUS);
-    STATIC_RESP!(AlreadyReported, StatusCode::ALREADY_REPORTED);
-
-    STATIC_RESP!(MultipleChoices, StatusCode::MULTIPLE_CHOICES);
-    STATIC_RESP!(MovedPermanently, StatusCode::MOVED_PERMANENTLY);
-    STATIC_RESP!(Found, StatusCode::FOUND);
-    STATIC_RESP!(SeeOther, StatusCode::SEE_OTHER);
-    STATIC_RESP!(NotModified, StatusCode::NOT_MODIFIED);
-    STATIC_RESP!(UseProxy, StatusCode::USE_PROXY);
-    STATIC_RESP!(TemporaryRedirect, StatusCode::TEMPORARY_REDIRECT);
-    STATIC_RESP!(PermanentRedirect, StatusCode::PERMANENT_REDIRECT);
-
-    STATIC_RESP!(BadRequest, StatusCode::BAD_REQUEST);
-    STATIC_RESP!(NotFound, StatusCode::NOT_FOUND);
-    STATIC_RESP!(Unauthorized, StatusCode::UNAUTHORIZED);
-    STATIC_RESP!(PaymentRequired, StatusCode::PAYMENT_REQUIRED);
-    STATIC_RESP!(Forbidden, StatusCode::FORBIDDEN);
-    STATIC_RESP!(MethodNotAllowed, StatusCode::METHOD_NOT_ALLOWED);
-    STATIC_RESP!(NotAcceptable, StatusCode::NOT_ACCEPTABLE);
-    STATIC_RESP!(
-        ProxyAuthenticationRequired,
-        StatusCode::PROXY_AUTHENTICATION_REQUIRED
-    );
-    STATIC_RESP!(RequestTimeout, StatusCode::REQUEST_TIMEOUT);
-    STATIC_RESP!(Conflict, StatusCode::CONFLICT);
-    STATIC_RESP!(Gone, StatusCode::GONE);
-    STATIC_RESP!(LengthRequired, StatusCode::LENGTH_REQUIRED);
-    STATIC_RESP!(PreconditionFailed, StatusCode::PRECONDITION_FAILED);
-    STATIC_RESP!(PreconditionRequired, StatusCode::PRECONDITION_REQUIRED);
-    STATIC_RESP!(PayloadTooLarge, StatusCode::PAYLOAD_TOO_LARGE);
-    STATIC_RESP!(UriTooLong, StatusCode::URI_TOO_LONG);
-    STATIC_RESP!(UnsupportedMediaType, StatusCode::UNSUPPORTED_MEDIA_TYPE);
-    STATIC_RESP!(RangeNotSatisfiable, StatusCode::RANGE_NOT_SATISFIABLE);
-    STATIC_RESP!(ExpectationFailed, StatusCode::EXPECTATION_FAILED);
-    STATIC_RESP!(UnprocessableEntity, StatusCode::UNPROCESSABLE_ENTITY);
-    STATIC_RESP!(TooManyRequests, StatusCode::TOO_MANY_REQUESTS);
-
-    STATIC_RESP!(InternalServerError, StatusCode::INTERNAL_SERVER_ERROR);
-    STATIC_RESP!(NotImplemented, StatusCode::NOT_IMPLEMENTED);
-    STATIC_RESP!(BadGateway, StatusCode::BAD_GATEWAY);
-    STATIC_RESP!(ServiceUnavailable, StatusCode::SERVICE_UNAVAILABLE);
-    STATIC_RESP!(GatewayTimeout, StatusCode::GATEWAY_TIMEOUT);
-    STATIC_RESP!(VersionNotSupported, StatusCode::HTTP_VERSION_NOT_SUPPORTED);
-    STATIC_RESP!(VariantAlsoNegotiates, StatusCode::VARIANT_ALSO_NEGOTIATES);
-    STATIC_RESP!(InsufficientStorage, StatusCode::INSUFFICIENT_STORAGE);
-    STATIC_RESP!(LoopDetected, StatusCode::LOOP_DETECTED);
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::body::Body;
-    use crate::response::Response;
-    use http::StatusCode;
-
-    #[test]
-    fn test_build() {
-        let resp = Response::Ok().body(Body::Empty);
-        assert_eq!(resp.status(), StatusCode::OK);
-    }
-}
diff --git a/actix-http/src/lib.rs b/actix-http/src/lib.rs
index b52e8179c..574d4ef68 100644
--- a/actix-http/src/lib.rs
+++ b/actix-http/src/lib.rs
@@ -1,12 +1,29 @@
-//! Basic http primitives for actix-net framework.
+//! HTTP primitives for the Actix ecosystem.
+//!
+//! ## Crate Features
+//! | Feature          | Functionality                                         |
+//! | ---------------- | ----------------------------------------------------- |
+//! | `openssl`        | TLS support via [OpenSSL].                            |
+//! | `rustls`         | TLS support via [rustls].                             |
+//! | `compress`       | Payload compression support. (Deflate, Gzip & Brotli) |
+//! | `cookies`        | Support for cookies backed by the [cookie] crate.     |
+//! | `secure-cookies` | Adds for secure cookies. Enables `cookies` feature.   |
+//! | `trust-dns`      | Use [trust-dns] as the client DNS resolver.           |
+//!
+//! [OpenSSL]: https://crates.io/crates/openssl
+//! [rustls]: https://crates.io/crates/rustls
+//! [cookie]: https://crates.io/crates/cookie
+//! [trust-dns]: https://crates.io/crates/trust-dns
 
-#![deny(rust_2018_idioms)]
+#![deny(rust_2018_idioms, nonstandard_style)]
 #![allow(
     clippy::type_complexity,
     clippy::too_many_arguments,
     clippy::new_without_default,
     clippy::borrow_interior_mutable_const
 )]
+#![doc(html_logo_url = "https://actix.rs/img/logo.png")]
+#![doc(html_favicon_url = "https://actix.rs/favicon.ico")]
 
 #[macro_use]
 extern crate log;
@@ -17,15 +34,14 @@ mod macros;
 pub mod body;
 mod builder;
 pub mod client;
-mod cloneable;
 mod config;
 #[cfg(feature = "compress")]
 pub mod encoding;
 mod extensions;
 mod header;
 mod helpers;
-mod httpcodes;
-pub mod httpmessage;
+mod http_codes;
+mod http_message;
 mod message;
 mod payload;
 mod request;
@@ -33,18 +49,20 @@ mod response;
 mod service;
 mod time_parser;
 
-pub use cookie;
 pub mod error;
 pub mod h1;
 pub mod h2;
 pub mod test;
 pub mod ws;
 
+#[cfg(feature = "cookies")]
+pub use cookie;
+
 pub use self::builder::HttpServiceBuilder;
 pub use self::config::{KeepAlive, ServiceConfig};
 pub use self::error::{Error, ResponseError, Result};
 pub use self::extensions::Extensions;
-pub use self::httpmessage::HttpMessage;
+pub use self::http_message::HttpMessage;
 pub use self::message::{Message, RequestHead, RequestHeadType, ResponseHead};
 pub use self::payload::{Payload, PayloadStream};
 pub use self::request::Request;
@@ -52,7 +70,7 @@ pub use self::response::{Response, ResponseBuilder};
 pub use self::service::HttpService;
 
 pub mod http {
-    //! Various HTTP related types
+    //! Various HTTP related types.
 
     // re-exports
     pub use http::header::{HeaderName, HeaderValue};
@@ -60,10 +78,11 @@ pub mod http {
     pub use http::{uri, Error, Uri};
     pub use http::{Method, StatusCode, Version};
 
+    #[cfg(feature = "cookies")]
     pub use crate::cookie::{Cookie, CookieBuilder};
     pub use crate::header::HeaderMap;
 
-    /// Various http headers
+    /// A collection of HTTP headers and helpers.
     pub mod header {
         pub use crate::header::*;
     }
@@ -71,9 +90,49 @@ pub mod http {
     pub use crate::message::ConnectionType;
 }
 
-/// Http protocol
+/// A major HTTP protocol version.
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+#[non_exhaustive]
 pub enum Protocol {
     Http1,
     Http2,
+    Http3,
+}
+
+type ConnectCallback<IO> = dyn Fn(&IO, &mut Extensions);
+
+/// Container for data that extract with ConnectCallback.
+///
+/// # Implementation Details
+/// Uses Option to reduce necessary allocations when merging with request extensions.
+pub(crate) struct OnConnectData(Option<Extensions>);
+
+impl Default for OnConnectData {
+    fn default() -> Self {
+        Self(None)
+    }
+}
+
+impl OnConnectData {
+    /// Construct by calling the on-connect callback with the underlying transport I/O.
+    pub(crate) fn from_io<T>(
+        io: &T,
+        on_connect_ext: Option<&ConnectCallback<T>>,
+    ) -> Self {
+        let ext = on_connect_ext.map(|handler| {
+            let mut extensions = Extensions::new();
+            handler(io, &mut extensions);
+            extensions
+        });
+
+        Self(ext)
+    }
+
+    /// Merge self into given request's extensions.
+    #[inline]
+    pub(crate) fn merge_into(&mut self, req: &mut Request) {
+        if let Some(ref mut ext) = self.0 {
+            req.head.extensions.get_mut().drain_from(ext);
+        }
+    }
 }
diff --git a/actix-http/src/message.rs b/actix-http/src/message.rs
index 5e53f73b6..6438ccba0 100644
--- a/actix-http/src/message.rs
+++ b/actix-http/src/message.rs
@@ -3,7 +3,6 @@ use std::net;
 use std::rc::Rc;
 
 use bitflags::bitflags;
-use copyless::BoxHelper;
 
 use crate::extensions::Extensions;
 use crate::header::HeaderMap;
@@ -14,8 +13,10 @@ use crate::http::{header, Method, StatusCode, Uri, Version};
 pub enum ConnectionType {
     /// Close connection after response
     Close,
+
     /// Keep connection alive after response
     KeepAlive,
+
     /// Connection is upgraded to different type
     Upgrade,
 }
@@ -35,7 +36,9 @@ bitflags! {
 pub trait Head: Default + 'static {
     fn clear(&mut self);
 
-    fn pool() -> &'static MessagePool<Self>;
+    fn with_pool<F, R>(f: F) -> R
+    where
+        F: FnOnce(&MessagePool<Self>) -> R;
 }
 
 #[derive(Debug)]
@@ -67,11 +70,14 @@ impl Head for RequestHead {
     fn clear(&mut self) {
         self.flags = Flags::empty();
         self.headers.clear();
-        self.extensions.borrow_mut().clear();
+        self.extensions.get_mut().clear();
     }
 
-    fn pool() -> &'static MessagePool<Self> {
-        REQUEST_POOL.with(|p| *p)
+    fn with_pool<F, R>(f: F) -> R
+    where
+        F: FnOnce(&MessagePool<Self>) -> R,
+    {
+        REQUEST_POOL.with(|p| f(p))
     }
 }
 
@@ -339,21 +345,15 @@ impl ResponseHead {
 }
 
 pub struct Message<T: Head> {
+    // Rc here should not be cloned by anyone.
+    // It's used to reuse allocation of T and no shared ownership is allowed.
     head: Rc<T>,
 }
 
 impl<T: Head> Message<T> {
     /// Get new message from the pool of objects
     pub fn new() -> Self {
-        T::pool().get_message()
-    }
-}
-
-impl<T: Head> Clone for Message<T> {
-    fn clone(&self) -> Self {
-        Message {
-            head: self.head.clone(),
-        }
+        T::with_pool(|p| p.get_message())
     }
 }
 
@@ -373,9 +373,7 @@ impl<T: Head> std::ops::DerefMut for Message<T> {
 
 impl<T: Head> Drop for Message<T> {
     fn drop(&mut self) {
-        if Rc::strong_count(&self.head) == 1 {
-            T::pool().release(self.head.clone());
-        }
+        T::with_pool(|p| p.release(self.head.clone()))
     }
 }
 
@@ -427,22 +425,23 @@ pub struct MessagePool<T: Head>(RefCell<Vec<Rc<T>>>);
 /// Request's objects pool
 pub struct BoxedResponsePool(RefCell<Vec<Box<ResponseHead>>>);
 
-thread_local!(static REQUEST_POOL: &'static MessagePool<RequestHead> = MessagePool::<RequestHead>::create());
-thread_local!(static RESPONSE_POOL: &'static BoxedResponsePool = BoxedResponsePool::create());
+thread_local!(static REQUEST_POOL: MessagePool<RequestHead> = MessagePool::<RequestHead>::create());
+thread_local!(static RESPONSE_POOL: BoxedResponsePool = BoxedResponsePool::create());
 
 impl<T: Head> MessagePool<T> {
-    fn create() -> &'static MessagePool<T> {
-        let pool = MessagePool(RefCell::new(Vec::with_capacity(128)));
-        Box::leak(Box::new(pool))
+    fn create() -> MessagePool<T> {
+        MessagePool(RefCell::new(Vec::with_capacity(128)))
     }
 
     /// Get message from the pool
     #[inline]
-    fn get_message(&'static self) -> Message<T> {
+    fn get_message(&self) -> Message<T> {
         if let Some(mut msg) = self.0.borrow_mut().pop() {
-            if let Some(r) = Rc::get_mut(&mut msg) {
-                r.clear();
-            }
+            // Message is put in pool only when it's the last copy.
+            // which means it's guaranteed to be unique when popped out.
+            Rc::get_mut(&mut msg)
+                .expect("Multiple copies exist")
+                .clear();
             Message { head: msg }
         } else {
             Message {
@@ -462,14 +461,13 @@ impl<T: Head> MessagePool<T> {
 }
 
 impl BoxedResponsePool {
-    fn create() -> &'static BoxedResponsePool {
-        let pool = BoxedResponsePool(RefCell::new(Vec::with_capacity(128)));
-        Box::leak(Box::new(pool))
+    fn create() -> BoxedResponsePool {
+        BoxedResponsePool(RefCell::new(Vec::with_capacity(128)))
     }
 
     /// Get message from the pool
     #[inline]
-    fn get_message(&'static self, status: StatusCode) -> BoxedResponseHead {
+    fn get_message(&self, status: StatusCode) -> BoxedResponseHead {
         if let Some(mut head) = self.0.borrow_mut().pop() {
             head.reason = None;
             head.status = status;
@@ -478,17 +476,17 @@ impl BoxedResponsePool {
             BoxedResponseHead { head: Some(head) }
         } else {
             BoxedResponseHead {
-                head: Some(Box::alloc().init(ResponseHead::new(status))),
+                head: Some(Box::new(ResponseHead::new(status))),
             }
         }
     }
 
     #[inline]
     /// Release request instance
-    fn release(&self, msg: Box<ResponseHead>) {
+    fn release(&self, mut msg: Box<ResponseHead>) {
         let v = &mut self.0.borrow_mut();
         if v.len() < 128 {
-            msg.extensions.borrow_mut().clear();
+            msg.extensions.get_mut().clear();
             v.push(msg);
         }
     }
diff --git a/actix-http/src/request.rs b/actix-http/src/request.rs
index 64e302441..197ec11c6 100644
--- a/actix-http/src/request.rs
+++ b/actix-http/src/request.rs
@@ -1,13 +1,17 @@
-use std::cell::{Ref, RefMut};
-use std::{fmt, net};
+//! HTTP requests.
+
+use std::{
+    cell::{Ref, RefMut},
+    fmt, net,
+};
 
 use http::{header, Method, Uri, Version};
 
 use crate::extensions::Extensions;
 use crate::header::HeaderMap;
-use crate::httpmessage::HttpMessage;
 use crate::message::{Message, RequestHead};
 use crate::payload::{Payload, PayloadStream};
+use crate::HttpMessage;
 
 /// Request
 pub struct Request<P = PayloadStream> {
@@ -23,6 +27,10 @@ impl<P> HttpMessage for Request<P> {
         &self.head().headers
     }
 
+    fn take_payload(&mut self) -> Payload<P> {
+        std::mem::replace(&mut self.payload, Payload::None)
+    }
+
     /// Request extensions
     #[inline]
     fn extensions(&self) -> Ref<'_, Extensions> {
@@ -34,10 +42,6 @@ impl<P> HttpMessage for Request<P> {
     fn extensions_mut(&self) -> RefMut<'_, Extensions> {
         self.head.extensions_mut()
     }
-
-    fn take_payload(&mut self) -> Payload<P> {
-        std::mem::replace(&mut self.payload, Payload::None)
-    }
 }
 
 impl From<Message<RequestHead>> for Request<PayloadStream> {
@@ -103,7 +107,7 @@ impl<P> Request<P> {
 
     #[inline]
     #[doc(hidden)]
-    /// Mutable reference to a http message part of the request
+    /// Mutable reference to a HTTP message part of the request
     pub fn head_mut(&mut self) -> &mut RequestHead {
         &mut *self.head
     }
@@ -154,10 +158,12 @@ impl<P> Request<P> {
         self.head().method == Method::CONNECT
     }
 
-    /// Peer socket address
+    /// Peer socket address.
     ///
-    /// Peer address is actual socket address, if proxy is used in front of
-    /// actix http server, then peer address would be address of this proxy.
+    /// Peer address is the directly connected peer's socket address. If a proxy is used in front of
+    /// the Actix Web server, then it would be address of this proxy.
+    ///
+    /// Will only return None when called in unit tests.
     #[inline]
     pub fn peer_addr(&self) -> Option<net::SocketAddr> {
         self.head().peer_addr
@@ -173,13 +179,17 @@ impl<P> fmt::Debug for Request<P> {
             self.method(),
             self.path()
         )?;
+
         if let Some(q) = self.uri().query().as_ref() {
             writeln!(f, "  query: ?{:?}", q)?;
         }
+
         writeln!(f, "  headers:")?;
-        for (key, val) in self.headers() {
+
+        for (key, val) in self.headers().iter() {
             writeln!(f, "    {:?}: {:?}", key, val)?;
         }
+
         Ok(())
     }
 }
diff --git a/actix-http/src/response.rs b/actix-http/src/response.rs
index 2def67168..471dacd28 100644
--- a/actix-http/src/response.rs
+++ b/actix-http/src/response.rs
@@ -1,23 +1,32 @@
-//! Http response
-use std::cell::{Ref, RefMut};
-use std::convert::TryFrom;
-use std::future::Future;
-use std::pin::Pin;
-use std::task::{Context, Poll};
-use std::{fmt, str};
+//! HTTP responses.
+
+use std::{
+    cell::{Ref, RefMut},
+    convert::TryInto,
+    fmt,
+    future::Future,
+    ops,
+    pin::Pin,
+    str,
+    task::{Context, Poll},
+};
 
 use bytes::{Bytes, BytesMut};
 use futures_core::Stream;
 use serde::Serialize;
 
 use crate::body::{Body, BodyStream, MessageBody, ResponseBody};
-use crate::cookie::{Cookie, CookieJar};
 use crate::error::Error;
 use crate::extensions::Extensions;
-use crate::header::{Header, IntoHeaderValue};
-use crate::http::header::{self, HeaderName, HeaderValue};
+use crate::header::{IntoHeaderPair, IntoHeaderValue};
+use crate::http::header::{self, HeaderName};
 use crate::http::{Error as HttpError, HeaderMap, StatusCode};
 use crate::message::{BoxedResponseHead, ConnectionType, ResponseHead};
+#[cfg(feature = "cookies")]
+use crate::{
+    cookie::{Cookie, CookieJar},
+    http::header::HeaderValue,
+};
 
 /// An HTTP Response
 pub struct Response<B = Body> {
@@ -27,13 +36,13 @@ pub struct Response<B = Body> {
 }
 
 impl Response<Body> {
-    /// Create http response builder with specific status.
+    /// Create HTTP response builder with specific status.
     #[inline]
     pub fn build(status: StatusCode) -> ResponseBuilder {
         ResponseBuilder::new(status)
     }
 
-    /// Create http response builder
+    /// Create HTTP response builder
     #[inline]
     pub fn build_from<T: Into<ResponseBuilder>>(source: T) -> ResponseBuilder {
         source.into()
@@ -92,7 +101,7 @@ impl<B> Response<B> {
     }
 
     #[inline]
-    /// Mutable reference to a http message part of the response
+    /// Mutable reference to a HTTP message part of the response
     pub fn head_mut(&mut self) -> &mut ResponseHead {
         &mut *self.head
     }
@@ -128,6 +137,7 @@ impl<B> Response<B> {
     }
 
     /// Get an iterator for the cookies set by this response
+    #[cfg(feature = "cookies")]
     #[inline]
     pub fn cookies(&self) -> CookieIter<'_> {
         CookieIter {
@@ -136,6 +146,7 @@ impl<B> Response<B> {
     }
 
     /// Add a cookie to this response
+    #[cfg(feature = "cookies")]
     #[inline]
     pub fn add_cookie(&mut self, cookie: &Cookie<'_>) -> Result<(), HttpError> {
         let h = &mut self.head.headers;
@@ -148,6 +159,7 @@ impl<B> Response<B> {
 
     /// Remove all cookies with the given name from this response. Returns
     /// the number of cookies removed.
+    #[cfg(feature = "cookies")]
     #[inline]
     pub fn del_cookie(&mut self, name: &str) -> usize {
         let h = &mut self.head.headers;
@@ -293,10 +305,12 @@ impl Future for Response {
     }
 }
 
+#[cfg(feature = "cookies")]
 pub struct CookieIter<'a> {
     iter: header::GetAll<'a>,
 }
 
+#[cfg(feature = "cookies")]
 impl<'a> Iterator for CookieIter<'a> {
     type Item = Cookie<'a>;
 
@@ -311,13 +325,13 @@ impl<'a> Iterator for CookieIter<'a> {
     }
 }
 
-/// An HTTP response builder
+/// An HTTP response builder.
 ///
-/// This type can be used to construct an instance of `Response` through a
-/// builder-like pattern.
+/// This type can be used to construct an instance of `Response` through a builder-like pattern.
 pub struct ResponseBuilder {
     head: Option<BoxedResponseHead>,
     err: Option<HttpError>,
+    #[cfg(feature = "cookies")]
     cookies: Option<CookieJar>,
 }
 
@@ -328,6 +342,7 @@ impl ResponseBuilder {
         ResponseBuilder {
             head: Some(BoxedResponseHead::new(status)),
             err: None,
+            #[cfg(feature = "cookies")]
             cookies: None,
         }
     }
@@ -341,93 +356,98 @@ impl ResponseBuilder {
         self
     }
 
-    /// Set a header.
+    /// Insert a header, replacing any that were set with an equivalent field name.
     ///
     /// ```rust
-    /// use actix_http::{http, Request, Response, Result};
+    /// # use actix_http::Response;
+    /// use actix_http::http::header::ContentType;
     ///
-    /// fn index(req: Request) -> Result<Response> {
-    ///     Ok(Response::Ok()
-    ///         .set(http::header::IfModifiedSince(
-    ///             "Sun, 07 Nov 1994 08:48:37 GMT".parse()?,
-    ///         ))
-    ///         .finish())
-    /// }
+    /// Response::Ok()
+    ///     .insert_header(ContentType(mime::APPLICATION_JSON))
+    ///     .insert_header(("X-TEST", "value"))
+    ///     .finish();
     /// ```
-    #[doc(hidden)]
-    pub fn set<H: Header>(&mut self, hdr: H) -> &mut Self {
+    pub fn insert_header<H>(&mut self, header: H) -> &mut Self
+    where
+        H: IntoHeaderPair,
+    {
         if let Some(parts) = parts(&mut self.head, &self.err) {
-            match hdr.try_into() {
-                Ok(value) => {
-                    parts.headers.append(H::name(), value);
+            match header.try_into_header_pair() {
+                Ok((key, value)) => {
+                    parts.headers.insert(key, value);
                 }
                 Err(e) => self.err = Some(e.into()),
-            }
+            };
         }
+
         self
     }
 
-    /// Append a header to existing headers.
+    /// Append a header, keeping any that were set with an equivalent field name.
     ///
     /// ```rust
-    /// use actix_http::{http, Request, Response};
+    /// # use actix_http::Response;
+    /// use actix_http::http::header::ContentType;
     ///
-    /// fn index(req: Request) -> Response {
-    ///     Response::Ok()
-    ///         .header("X-TEST", "value")
-    ///         .header(http::header::CONTENT_TYPE, "application/json")
-    ///         .finish()
-    /// }
+    /// Response::Ok()
+    ///     .append_header(ContentType(mime::APPLICATION_JSON))
+    ///     .append_header(("X-TEST", "value1"))
+    ///     .append_header(("X-TEST", "value2"))
+    ///     .finish();
     /// ```
-    pub fn header<K, V>(&mut self, key: K, value: V) -> &mut Self
+    pub fn append_header<H>(&mut self, header: H) -> &mut Self
     where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
+        H: IntoHeaderPair,
     {
         if let Some(parts) = parts(&mut self.head, &self.err) {
-            match HeaderName::try_from(key) {
-                Ok(key) => match value.try_into() {
-                    Ok(value) => {
-                        parts.headers.append(key, value);
-                    }
-                    Err(e) => self.err = Some(e.into()),
-                },
+            match header.try_into_header_pair() {
+                Ok((key, value)) => parts.headers.append(key, value),
                 Err(e) => self.err = Some(e.into()),
             };
         }
+
         self
     }
 
-    /// Set a header.
-    ///
-    /// ```rust
-    /// use actix_http::{http, Request, Response};
-    ///
-    /// fn index(req: Request) -> Response {
-    ///     Response::Ok()
-    ///         .set_header("X-TEST", "value")
-    ///         .set_header(http::header::CONTENT_TYPE, "application/json")
-    ///         .finish()
-    /// }
-    /// ```
+    /// Replaced with [`Self::insert_header()`].
+    #[deprecated = "Replaced with `insert_header((key, value))`."]
     pub fn set_header<K, V>(&mut self, key: K, value: V) -> &mut Self
     where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
+        K: TryInto<HeaderName>,
+        K::Error: Into<HttpError>,
         V: IntoHeaderValue,
     {
-        if let Some(parts) = parts(&mut self.head, &self.err) {
-            match HeaderName::try_from(key) {
-                Ok(key) => match value.try_into() {
-                    Ok(value) => {
-                        parts.headers.insert(key, value);
-                    }
-                    Err(e) => self.err = Some(e.into()),
-                },
-                Err(e) => self.err = Some(e.into()),
-            };
+        if self.err.is_some() {
+            return self;
         }
+
+        match (key.try_into(), value.try_into_value()) {
+            (Ok(name), Ok(value)) => return self.insert_header((name, value)),
+            (Err(err), _) => self.err = Some(err.into()),
+            (_, Err(err)) => self.err = Some(err.into()),
+        }
+
+        self
+    }
+
+    /// Replaced with [`Self::append_header()`].
+    #[deprecated = "Replaced with `append_header((key, value))`."]
+    pub fn header<K, V>(&mut self, key: K, value: V) -> &mut Self
+    where
+        K: TryInto<HeaderName>,
+        K::Error: Into<HttpError>,
+        V: IntoHeaderValue,
+    {
+        if self.err.is_some() {
+            return self;
+        }
+
+        match (key.try_into(), value.try_into_value()) {
+            (Ok(name), Ok(value)) => return self.append_header((name, value)),
+            (Err(err), _) => self.err = Some(err.into()),
+            (_, Err(err)) => self.err = Some(err.into()),
+        }
+
         self
     }
 
@@ -458,7 +478,12 @@ impl ResponseBuilder {
         if let Some(parts) = parts(&mut self.head, &self.err) {
             parts.set_connection_type(ConnectionType::Upgrade);
         }
-        self.set_header(header::UPGRADE, value)
+
+        if let Ok(value) = value.try_into_value() {
+            self.insert_header((header::UPGRADE, value));
+        }
+
+        self
     }
 
     /// Force close connection, even if it is marked as keep-alive
@@ -473,7 +498,7 @@ impl ResponseBuilder {
     /// Disable chunked transfer encoding for HTTP/1.1 streaming responses.
     #[inline]
     pub fn no_chunking(&mut self, len: u64) -> &mut Self {
-        self.header(header::CONTENT_LENGTH, len);
+        self.insert_header((header::CONTENT_LENGTH, len));
 
         if let Some(parts) = parts(&mut self.head, &self.err) {
             parts.no_chunking(true);
@@ -481,15 +506,14 @@ impl ResponseBuilder {
         self
     }
 
-    /// Set response content type
+    /// Set response content type.
     #[inline]
     pub fn content_type<V>(&mut self, value: V) -> &mut Self
     where
-        HeaderValue: TryFrom<V>,
-        <HeaderValue as TryFrom<V>>::Error: Into<HttpError>,
+        V: IntoHeaderValue,
     {
         if let Some(parts) = parts(&mut self.head, &self.err) {
-            match HeaderValue::try_from(value) {
+            match value.try_into_value() {
                 Ok(value) => {
                     parts.headers.insert(header::CONTENT_TYPE, value);
                 }
@@ -517,6 +541,7 @@ impl ResponseBuilder {
     ///         .finish()
     /// }
     /// ```
+    #[cfg(feature = "cookies")]
     pub fn cookie<'c>(&mut self, cookie: Cookie<'c>) -> &mut Self {
         if self.cookies.is_none() {
             let mut jar = CookieJar::new();
@@ -543,6 +568,7 @@ impl ResponseBuilder {
     ///     builder.finish()
     /// }
     /// ```
+    #[cfg(feature = "cookies")]
     pub fn del_cookie<'a>(&mut self, cookie: &Cookie<'a>) -> &mut Self {
         if self.cookies.is_none() {
             self.cookies = Some(CookieJar::new())
@@ -554,8 +580,9 @@ impl ResponseBuilder {
         self
     }
 
-    /// This method calls provided closure with builder reference if value is
-    /// true.
+    /// This method calls provided closure with builder reference if value is `true`.
+    #[doc(hidden)]
+    #[deprecated = "Use an if statement."]
     pub fn if_true<F>(&mut self, value: bool, f: F) -> &mut Self
     where
         F: FnOnce(&mut ResponseBuilder),
@@ -566,8 +593,9 @@ impl ResponseBuilder {
         self
     }
 
-    /// This method calls provided closure with builder reference if value is
-    /// Some.
+    /// This method calls provided closure with builder reference if value is `Some`.
+    #[doc(hidden)]
+    #[deprecated = "Use an if-let construction."]
     pub fn if_some<T, F>(&mut self, value: Option<T>, f: F) -> &mut Self
     where
         F: FnOnce(T, &mut ResponseBuilder),
@@ -608,8 +636,11 @@ impl ResponseBuilder {
             return Response::from(Error::from(e)).into_body();
         }
 
+        // allow unused mut when cookies feature is disabled
+        #[allow(unused_mut)]
         let mut response = self.head.take().expect("cannot reuse response builder");
 
+        #[cfg(feature = "cookies")]
         if let Some(ref jar) = self.cookies {
             for cookie in jar.delta() {
                 match HeaderValue::from_str(&cookie.to_string()) {
@@ -638,27 +669,24 @@ impl ResponseBuilder {
         self.body(Body::from_message(BodyStream::new(stream)))
     }
 
-    #[inline]
     /// Set a json body and generate `Response`
     ///
     /// `ResponseBuilder` can not be used after this call.
-    pub fn json<T: Serialize>(&mut self, value: T) -> Response {
-        self.json2(&value)
-    }
-
-    /// Set a json body and generate `Response`
-    ///
-    /// `ResponseBuilder` can not be used after this call.
-    pub fn json2<T: Serialize>(&mut self, value: &T) -> Response {
-        match serde_json::to_string(value) {
+    pub fn json<T>(&mut self, value: T) -> Response
+    where
+        T: ops::Deref,
+        T::Target: Serialize,
+    {
+        match serde_json::to_string(&*value) {
             Ok(body) => {
                 let contains = if let Some(parts) = parts(&mut self.head, &self.err) {
                     parts.headers.contains_key(header::CONTENT_TYPE)
                 } else {
                     true
                 };
+
                 if !contains {
-                    self.header(header::CONTENT_TYPE, "application/json");
+                    self.insert_header(header::ContentType(mime::APPLICATION_JSON));
                 }
 
                 self.body(Body::from(body))
@@ -680,6 +708,7 @@ impl ResponseBuilder {
         ResponseBuilder {
             head: self.head.take(),
             err: self.err.take(),
+            #[cfg(feature = "cookies")]
             cookies: self.cookies.take(),
         }
     }
@@ -699,21 +728,28 @@ fn parts<'a>(
 /// Convert `Response` to a `ResponseBuilder`. Body get dropped.
 impl<B> From<Response<B>> for ResponseBuilder {
     fn from(res: Response<B>) -> ResponseBuilder {
-        // If this response has cookies, load them into a jar
-        let mut jar: Option<CookieJar> = None;
-        for c in res.cookies() {
-            if let Some(ref mut j) = jar {
-                j.add_original(c.into_owned());
-            } else {
-                let mut j = CookieJar::new();
-                j.add_original(c.into_owned());
-                jar = Some(j);
+        #[cfg(feature = "cookies")]
+        let jar = {
+            // If this response has cookies, load them into a jar
+            let mut jar: Option<CookieJar> = None;
+
+            for c in res.cookies() {
+                if let Some(ref mut j) = jar {
+                    j.add_original(c.into_owned());
+                } else {
+                    let mut j = CookieJar::new();
+                    j.add_original(c.into_owned());
+                    jar = Some(j);
+                }
             }
-        }
+
+            jar
+        };
 
         ResponseBuilder {
             head: Some(res.head),
             err: None,
+            #[cfg(feature = "cookies")]
             cookies: jar,
         }
     }
@@ -722,33 +758,42 @@ impl<B> From<Response<B>> for ResponseBuilder {
 /// Convert `ResponseHead` to a `ResponseBuilder`
 impl<'a> From<&'a ResponseHead> for ResponseBuilder {
     fn from(head: &'a ResponseHead) -> ResponseBuilder {
-        // If this response has cookies, load them into a jar
-        let mut jar: Option<CookieJar> = None;
-
-        let cookies = CookieIter {
-            iter: head.headers.get_all(header::SET_COOKIE),
-        };
-        for c in cookies {
-            if let Some(ref mut j) = jar {
-                j.add_original(c.into_owned());
-            } else {
-                let mut j = CookieJar::new();
-                j.add_original(c.into_owned());
-                jar = Some(j);
-            }
-        }
-
         let mut msg = BoxedResponseHead::new(head.status);
         msg.version = head.version;
         msg.reason = head.reason;
-        for (k, v) in &head.headers {
+
+        for (k, v) in head.headers.iter() {
             msg.headers.append(k.clone(), v.clone());
         }
+
         msg.no_chunking(!head.chunked());
 
+        #[cfg(feature = "cookies")]
+        let jar = {
+            // If this response has cookies, load them into a jar
+            let mut jar: Option<CookieJar> = None;
+
+            let cookies = CookieIter {
+                iter: head.headers.get_all(header::SET_COOKIE),
+            };
+
+            for c in cookies {
+                if let Some(ref mut j) = jar {
+                    j.add_original(c.into_owned());
+                } else {
+                    let mut j = CookieJar::new();
+                    j.add_original(c.into_owned());
+                    jar = Some(j);
+                }
+            }
+
+            jar
+        };
+
         ResponseBuilder {
             head: Some(msg),
             err: None,
+            #[cfg(feature = "cookies")]
             cookies: jar,
         }
     }
@@ -800,7 +845,7 @@ impl From<ResponseBuilder> for Response {
 impl From<&'static str> for Response {
     fn from(val: &'static str) -> Self {
         Response::Ok()
-            .content_type("text/plain; charset=utf-8")
+            .content_type(mime::TEXT_PLAIN_UTF_8)
             .body(val)
     }
 }
@@ -808,7 +853,7 @@ impl From<&'static str> for Response {
 impl From<&'static [u8]> for Response {
     fn from(val: &'static [u8]) -> Self {
         Response::Ok()
-            .content_type("application/octet-stream")
+            .content_type(mime::APPLICATION_OCTET_STREAM)
             .body(val)
     }
 }
@@ -816,7 +861,7 @@ impl From<&'static [u8]> for Response {
 impl From<String> for Response {
     fn from(val: String) -> Self {
         Response::Ok()
-            .content_type("text/plain; charset=utf-8")
+            .content_type(mime::TEXT_PLAIN_UTF_8)
             .body(val)
     }
 }
@@ -824,7 +869,7 @@ impl From<String> for Response {
 impl<'a> From<&'a String> for Response {
     fn from(val: &'a String) -> Self {
         Response::Ok()
-            .content_type("text/plain; charset=utf-8")
+            .content_type(mime::TEXT_PLAIN_UTF_8)
             .body(val)
     }
 }
@@ -832,7 +877,7 @@ impl<'a> From<&'a String> for Response {
 impl From<Bytes> for Response {
     fn from(val: Bytes) -> Self {
         Response::Ok()
-            .content_type("application/octet-stream")
+            .content_type(mime::APPLICATION_OCTET_STREAM)
             .body(val)
     }
 }
@@ -840,22 +885,25 @@ impl From<Bytes> for Response {
 impl From<BytesMut> for Response {
     fn from(val: BytesMut) -> Self {
         Response::Ok()
-            .content_type("application/octet-stream")
+            .content_type(mime::APPLICATION_OCTET_STREAM)
             .body(val)
     }
 }
 
 #[cfg(test)]
 mod tests {
+    use serde_json::json;
+
     use super::*;
     use crate::body::Body;
     use crate::http::header::{HeaderValue, CONTENT_TYPE, COOKIE, SET_COOKIE};
+    use crate::HttpMessage;
 
     #[test]
     fn test_debug() {
         let resp = Response::Ok()
-            .header(COOKIE, HeaderValue::from_static("cookie1=value1; "))
-            .header(COOKIE, HeaderValue::from_static("cookie2=value2; "))
+            .append_header((COOKIE, HeaderValue::from_static("cookie1=value1; ")))
+            .append_header((COOKIE, HeaderValue::from_static("cookie2=value2; ")))
             .finish();
         let dbg = format!("{:?}", resp);
         assert!(dbg.contains("Response"));
@@ -863,11 +911,9 @@ mod tests {
 
     #[test]
     fn test_response_cookies() {
-        use crate::httpmessage::HttpMessage;
-
         let req = crate::test::TestRequest::default()
-            .header(COOKIE, "cookie1=value1")
-            .header(COOKIE, "cookie2=value2")
+            .append_header((COOKIE, "cookie1=value1"))
+            .append_header((COOKIE, "cookie2=value2"))
             .finish();
         let cookies = req.cookies().unwrap();
 
@@ -880,16 +926,20 @@ mod tests {
                     .max_age(time::Duration::days(1))
                     .finish(),
             )
-            .del_cookie(&cookies[1])
+            .del_cookie(&cookies[0])
             .finish();
 
-        let mut val: Vec<_> = resp
+        let mut val = resp
             .headers()
             .get_all(SET_COOKIE)
             .map(|v| v.to_str().unwrap().to_owned())
-            .collect();
+            .collect::<Vec<_>>();
         val.sort();
+
+        // the .del_cookie call
         assert!(val[0].starts_with("cookie1=; Max-Age=0;"));
+
+        // the .cookie call
         assert_eq!(
             val[1],
             "name=value; HttpOnly; Path=/test; Domain=www.rust-lang.org; Max-Age=86400"
@@ -914,14 +964,14 @@ mod tests {
 
         let mut iter = r.cookies();
         let v = iter.next().unwrap();
-        assert_eq!((v.name(), v.value()), ("cookie3", "val300"));
-        let v = iter.next().unwrap();
         assert_eq!((v.name(), v.value()), ("original", "val100"));
+        let v = iter.next().unwrap();
+        assert_eq!((v.name(), v.value()), ("cookie3", "val300"));
     }
 
     #[test]
     fn test_basic_builder() {
-        let resp = Response::Ok().header("X-TEST", "value").finish();
+        let resp = Response::Ok().insert_header(("X-TEST", "value")).finish();
         assert_eq!(resp.status(), StatusCode::OK);
     }
 
@@ -962,26 +1012,8 @@ mod tests {
     #[test]
     fn test_json_ct() {
         let resp = Response::build(StatusCode::OK)
-            .header(CONTENT_TYPE, "text/json")
-            .json(vec!["v1", "v2", "v3"]);
-        let ct = resp.headers().get(CONTENT_TYPE).unwrap();
-        assert_eq!(ct, HeaderValue::from_static("text/json"));
-        assert_eq!(resp.body().get_ref(), b"[\"v1\",\"v2\",\"v3\"]");
-    }
-
-    #[test]
-    fn test_json2() {
-        let resp = Response::build(StatusCode::OK).json2(&vec!["v1", "v2", "v3"]);
-        let ct = resp.headers().get(CONTENT_TYPE).unwrap();
-        assert_eq!(ct, HeaderValue::from_static("application/json"));
-        assert_eq!(resp.body().get_ref(), b"[\"v1\",\"v2\",\"v3\"]");
-    }
-
-    #[test]
-    fn test_json2_ct() {
-        let resp = Response::build(StatusCode::OK)
-            .header(CONTENT_TYPE, "text/json")
-            .json2(&vec!["v1", "v2", "v3"]);
+            .insert_header((CONTENT_TYPE, "text/json"))
+            .json(&vec!["v1", "v2", "v3"]);
         let ct = resp.headers().get(CONTENT_TYPE).unwrap();
         assert_eq!(ct, HeaderValue::from_static("text/json"));
         assert_eq!(resp.body().get_ref(), b"[\"v1\",\"v2\",\"v3\"]");
@@ -1080,4 +1112,54 @@ mod tests {
         let cookie = resp.cookies().next().unwrap();
         assert_eq!((cookie.name(), cookie.value()), ("cookie1", "val100"));
     }
+
+    #[test]
+    fn response_builder_header_insert_kv() {
+        let mut res = Response::Ok();
+        res.insert_header(("Content-Type", "application/octet-stream"));
+        let res = res.finish();
+
+        assert_eq!(
+            res.headers().get("Content-Type"),
+            Some(&HeaderValue::from_static("application/octet-stream"))
+        );
+    }
+
+    #[test]
+    fn response_builder_header_insert_typed() {
+        let mut res = Response::Ok();
+        res.insert_header(header::ContentType(mime::APPLICATION_OCTET_STREAM));
+        let res = res.finish();
+
+        assert_eq!(
+            res.headers().get("Content-Type"),
+            Some(&HeaderValue::from_static("application/octet-stream"))
+        );
+    }
+
+    #[test]
+    fn response_builder_header_append_kv() {
+        let mut res = Response::Ok();
+        res.append_header(("Content-Type", "application/octet-stream"));
+        res.append_header(("Content-Type", "application/json"));
+        let res = res.finish();
+
+        let headers: Vec<_> = res.headers().get_all("Content-Type").cloned().collect();
+        assert_eq!(headers.len(), 2);
+        assert!(headers.contains(&HeaderValue::from_static("application/octet-stream")));
+        assert!(headers.contains(&HeaderValue::from_static("application/json")));
+    }
+
+    #[test]
+    fn response_builder_header_append_typed() {
+        let mut res = Response::Ok();
+        res.append_header(header::ContentType(mime::APPLICATION_OCTET_STREAM));
+        res.append_header(header::ContentType(mime::APPLICATION_JSON));
+        let res = res.finish();
+
+        let headers: Vec<_> = res.headers().get_all("Content-Type").cloned().collect();
+        assert_eq!(headers.len(), 2);
+        assert!(headers.contains(&HeaderValue::from_static("application/octet-stream")));
+        assert!(headers.contains(&HeaderValue::from_static("application/json")));
+    }
 }
diff --git a/actix-http/src/service.rs b/actix-http/src/service.rs
index 9ee579702..fee26dcc3 100644
--- a/actix-http/src/service.rs
+++ b/actix-http/src/service.rs
@@ -1,44 +1,41 @@
 use std::marker::PhantomData;
 use std::pin::Pin;
 use std::task::{Context, Poll};
-use std::{fmt, net, rc};
+use std::{fmt, net, rc::Rc};
 
 use actix_codec::{AsyncRead, AsyncWrite, Framed};
 use actix_rt::net::TcpStream;
 use actix_service::{pipeline_factory, IntoServiceFactory, Service, ServiceFactory};
 use bytes::Bytes;
 use futures_core::{ready, Future};
-use futures_util::future::ok;
 use h2::server::{self, Handshake};
 use pin_project::pin_project;
 
 use crate::body::MessageBody;
 use crate::builder::HttpServiceBuilder;
-use crate::cloneable::CloneableService;
 use crate::config::{KeepAlive, ServiceConfig};
 use crate::error::{DispatchError, Error};
-use crate::helpers::DataFactory;
 use crate::request::Request;
 use crate::response::Response;
-use crate::{h1, h2::Dispatcher, Protocol};
+use crate::{h1, h2::Dispatcher, ConnectCallback, OnConnectData, Protocol};
 
-/// `ServiceFactory` HTTP1.1/HTTP2 transport implementation
-pub struct HttpService<T, S, B, X = h1::ExpectHandler, U = h1::UpgradeHandler<T>> {
+/// A `ServiceFactory` for HTTP/1.1 or HTTP/2 protocol.
+pub struct HttpService<T, S, B, X = h1::ExpectHandler, U = h1::UpgradeHandler> {
     srv: S,
     cfg: ServiceConfig,
     expect: X,
     upgrade: Option<U>,
-    on_connect: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    _t: PhantomData<(T, B)>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
+    _phantom: PhantomData<B>,
 }
 
 impl<T, S, B> HttpService<T, S, B>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
 {
     /// Create builder for `HttpService` instance.
@@ -49,15 +46,15 @@ where
 
 impl<T, S, B> HttpService<T, S, B>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
 {
     /// Create new `HttpService` instance.
-    pub fn new<F: IntoServiceFactory<S>>(service: F) -> Self {
+    pub fn new<F: IntoServiceFactory<S, Request>>(service: F) -> Self {
         let cfg = ServiceConfig::new(KeepAlive::Timeout(5), 5000, 0, false, None);
 
         HttpService {
@@ -65,13 +62,13 @@ where
             srv: service.into_factory(),
             expect: h1::ExpectHandler,
             upgrade: None,
-            on_connect: None,
-            _t: PhantomData,
+            on_connect_ext: None,
+            _phantom: PhantomData,
         }
     }
 
     /// Create new `HttpService` instance with config.
-    pub(crate) fn with_config<F: IntoServiceFactory<S>>(
+    pub(crate) fn with_config<F: IntoServiceFactory<S, Request>>(
         cfg: ServiceConfig,
         service: F,
     ) -> Self {
@@ -80,19 +77,19 @@ where
             srv: service.into_factory(),
             expect: h1::ExpectHandler,
             upgrade: None,
-            on_connect: None,
-            _t: PhantomData,
+            on_connect_ext: None,
+            _phantom: PhantomData,
         }
     }
 }
 
 impl<T, S, B, X, U> HttpService<T, S, B, X, U>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody,
 {
     /// Provide service for `EXPECT: 100-Continue` support.
@@ -102,18 +99,18 @@ where
     /// request will be forwarded to main service.
     pub fn expect<X1>(self, expect: X1) -> HttpService<T, S, B, X1, U>
     where
-        X1: ServiceFactory<Config = (), Request = Request, Response = Request>,
+        X1: ServiceFactory<Request, Config = (), Response = Request>,
         X1::Error: Into<Error>,
         X1::InitError: fmt::Debug,
-        <X1::Service as Service>::Future: 'static,
+        <X1::Service as Service<Request>>::Future: 'static,
     {
         HttpService {
             expect,
             cfg: self.cfg,
             srv: self.srv,
             upgrade: self.upgrade,
-            on_connect: self.on_connect,
-            _t: PhantomData,
+            on_connect_ext: self.on_connect_ext,
+            _phantom: PhantomData,
         }
     }
 
@@ -123,69 +120,62 @@ where
     /// and this service get called with original request and framed object.
     pub fn upgrade<U1>(self, upgrade: Option<U1>) -> HttpService<T, S, B, X, U1>
     where
-        U1: ServiceFactory<
-            Config = (),
-            Request = (Request, Framed<T, h1::Codec>),
-            Response = (),
-        >,
+        U1: ServiceFactory<(Request, Framed<T, h1::Codec>), Config = (), Response = ()>,
         U1::Error: fmt::Display,
         U1::InitError: fmt::Debug,
-        <U1::Service as Service>::Future: 'static,
+        <U1::Service as Service<(Request, Framed<T, h1::Codec>)>>::Future: 'static,
     {
         HttpService {
             upgrade,
             cfg: self.cfg,
             srv: self.srv,
             expect: self.expect,
-            on_connect: self.on_connect,
-            _t: PhantomData,
+            on_connect_ext: self.on_connect_ext,
+            _phantom: PhantomData,
         }
     }
 
-    /// Set on connect callback.
-    pub(crate) fn on_connect(
-        mut self,
-        f: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    ) -> Self {
-        self.on_connect = f;
+    /// Set connect callback with mutable access to request data container.
+    pub(crate) fn on_connect_ext(mut self, f: Option<Rc<ConnectCallback<T>>>) -> Self {
+        self.on_connect_ext = f;
         self
     }
 }
 
 impl<S, B, X, U> HttpService<TcpStream, S, B, X, U>
 where
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
-    X: ServiceFactory<Config = (), Request = Request, Response = Request>,
+    X: ServiceFactory<Request, Config = (), Response = Request>,
     X::Error: Into<Error>,
     X::InitError: fmt::Debug,
-    <X::Service as Service>::Future: 'static,
+    <X::Service as Service<Request>>::Future: 'static,
     U: ServiceFactory<
+        (Request, Framed<TcpStream, h1::Codec>),
         Config = (),
-        Request = (Request, Framed<TcpStream, h1::Codec>),
         Response = (),
     >,
     U::Error: fmt::Display + Into<Error>,
     U::InitError: fmt::Debug,
-    <U::Service as Service>::Future: 'static,
+    <U::Service as Service<(Request, Framed<TcpStream, h1::Codec>)>>::Future: 'static,
 {
     /// Create simple tcp stream service
     pub fn tcp(
         self,
     ) -> impl ServiceFactory<
+        TcpStream,
         Config = (),
-        Request = TcpStream,
         Response = (),
         Error = DispatchError,
         InitError = (),
     > {
-        pipeline_factory(|io: TcpStream| {
+        pipeline_factory(|io: TcpStream| async {
             let peer_addr = io.peer_addr().ok();
-            ok((io, Protocol::Http1, peer_addr))
+            Ok((io, Protocol::Http1, peer_addr))
         })
         .and_then(self)
     }
@@ -194,39 +184,40 @@ where
 #[cfg(feature = "openssl")]
 mod openssl {
     use super::*;
-    use actix_tls::openssl::{Acceptor, SslAcceptor, SslStream};
-    use actix_tls::{openssl::HandshakeError, TlsError};
+    use actix_service::ServiceFactoryExt;
+    use actix_tls::accept::openssl::{Acceptor, SslAcceptor, SslError, SslStream};
+    use actix_tls::accept::TlsError;
 
     impl<S, B, X, U> HttpService<SslStream<TcpStream>, S, B, X, U>
     where
-        S: ServiceFactory<Config = (), Request = Request>,
+        S: ServiceFactory<Request, Config = ()>,
         S::Error: Into<Error> + 'static,
         S::InitError: fmt::Debug,
         S::Response: Into<Response<B>> + 'static,
-        <S::Service as Service>::Future: 'static,
+        <S::Service as Service<Request>>::Future: 'static,
         B: MessageBody + 'static,
-        X: ServiceFactory<Config = (), Request = Request, Response = Request>,
+        X: ServiceFactory<Request, Config = (), Response = Request>,
         X::Error: Into<Error>,
         X::InitError: fmt::Debug,
-        <X::Service as Service>::Future: 'static,
+        <X::Service as Service<Request>>::Future: 'static,
         U: ServiceFactory<
+            (Request, Framed<SslStream<TcpStream>, h1::Codec>),
             Config = (),
-            Request = (Request, Framed<SslStream<TcpStream>, h1::Codec>),
             Response = (),
         >,
         U::Error: fmt::Display + Into<Error>,
         U::InitError: fmt::Debug,
-        <U::Service as Service>::Future: 'static,
+        <U::Service as Service<(Request, Framed<SslStream<TcpStream>, h1::Codec>)>>::Future: 'static,
     {
         /// Create openssl based service
         pub fn openssl(
             self,
             acceptor: SslAcceptor,
         ) -> impl ServiceFactory<
+            TcpStream,
             Config = (),
-            Request = TcpStream,
             Response = (),
-            Error = TlsError<HandshakeError<TcpStream>, DispatchError>,
+            Error = TlsError<SslError, DispatchError>,
             InitError = (),
         > {
             pipeline_factory(
@@ -234,7 +225,7 @@ mod openssl {
                     .map_err(TlsError::Tls)
                     .map_init_err(|_| panic!()),
             )
-            .and_then(|io: SslStream<TcpStream>| {
+            .and_then(|io: SslStream<TcpStream>| async {
                 let proto = if let Some(protos) = io.ssl().selected_alpn_protocol() {
                     if protos.windows(2).any(|window| window == b"h2") {
                         Protocol::Http2
@@ -245,7 +236,7 @@ mod openssl {
                     Protocol::Http1
                 };
                 let peer_addr = io.get_ref().peer_addr().ok();
-                ok((io, proto, peer_addr))
+                Ok((io, proto, peer_addr))
             })
             .and_then(self.map_err(TlsError::Service))
         }
@@ -254,39 +245,42 @@ mod openssl {
 
 #[cfg(feature = "rustls")]
 mod rustls {
-    use super::*;
-    use actix_tls::rustls::{Acceptor, ServerConfig, Session, TlsStream};
-    use actix_tls::TlsError;
     use std::io;
 
+    use actix_tls::accept::rustls::{Acceptor, ServerConfig, Session, TlsStream};
+    use actix_tls::accept::TlsError;
+
+    use super::*;
+    use actix_service::ServiceFactoryExt;
+
     impl<S, B, X, U> HttpService<TlsStream<TcpStream>, S, B, X, U>
     where
-        S: ServiceFactory<Config = (), Request = Request>,
+        S: ServiceFactory<Request, Config = ()>,
         S::Error: Into<Error> + 'static,
         S::InitError: fmt::Debug,
         S::Response: Into<Response<B>> + 'static,
-        <S::Service as Service>::Future: 'static,
+        <S::Service as Service<Request>>::Future: 'static,
         B: MessageBody + 'static,
-        X: ServiceFactory<Config = (), Request = Request, Response = Request>,
+        X: ServiceFactory<Request, Config = (), Response = Request>,
         X::Error: Into<Error>,
         X::InitError: fmt::Debug,
-        <X::Service as Service>::Future: 'static,
+        <X::Service as Service<Request>>::Future: 'static,
         U: ServiceFactory<
+            (Request, Framed<TlsStream<TcpStream>, h1::Codec>),
             Config = (),
-            Request = (Request, Framed<TlsStream<TcpStream>, h1::Codec>),
             Response = (),
         >,
         U::Error: fmt::Display + Into<Error>,
         U::InitError: fmt::Debug,
-        <U::Service as Service>::Future: 'static,
+        <U::Service as Service<(Request, Framed<TlsStream<TcpStream>, h1::Codec>)>>::Future: 'static,
     {
         /// Create openssl based service
         pub fn rustls(
             self,
             mut config: ServerConfig,
         ) -> impl ServiceFactory<
+            TcpStream,
             Config = (),
-            Request = TcpStream,
             Response = (),
             Error = TlsError<io::Error, DispatchError>,
             InitError = (),
@@ -299,7 +293,7 @@ mod rustls {
                     .map_err(TlsError::Tls)
                     .map_init_err(|_| panic!()),
             )
-            .and_then(|io: TlsStream<TcpStream>| {
+            .and_then(|io: TlsStream<TcpStream>| async {
                 let proto = if let Some(protos) = io.get_ref().1.get_alpn_protocol() {
                     if protos.windows(2).any(|window| window == b"h2") {
                         Protocol::Http2
@@ -310,41 +304,37 @@ mod rustls {
                     Protocol::Http1
                 };
                 let peer_addr = io.get_ref().0.peer_addr().ok();
-                ok((io, proto, peer_addr))
+                Ok((io, proto, peer_addr))
             })
             .and_then(self.map_err(TlsError::Service))
         }
     }
 }
 
-impl<T, S, B, X, U> ServiceFactory for HttpService<T, S, B, X, U>
+impl<T, S, B, X, U> ServiceFactory<(T, Protocol, Option<net::SocketAddr>)>
+    for HttpService<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: ServiceFactory<Config = (), Request = Request>,
+    S: ServiceFactory<Request, Config = ()>,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
-    X: ServiceFactory<Config = (), Request = Request, Response = Request>,
+    X: ServiceFactory<Request, Config = (), Response = Request>,
     X::Error: Into<Error>,
     X::InitError: fmt::Debug,
-    <X::Service as Service>::Future: 'static,
-    U: ServiceFactory<
-        Config = (),
-        Request = (Request, Framed<T, h1::Codec>),
-        Response = (),
-    >,
+    <X::Service as Service<Request>>::Future: 'static,
+    U: ServiceFactory<(Request, Framed<T, h1::Codec>), Config = (), Response = ()>,
     U::Error: fmt::Display + Into<Error>,
     U::InitError: fmt::Debug,
-    <U::Service as Service>::Future: 'static,
+    <U::Service as Service<(Request, Framed<T, h1::Codec>)>>::Future: 'static,
 {
-    type Config = ();
-    type Request = (T, Protocol, Option<net::SocketAddr>);
     type Response = ();
     type Error = DispatchError;
-    type InitError = ();
+    type Config = ();
     type Service = HttpServiceHandler<T, S::Service, B, X::Service, U::Service>;
+    type InitError = ();
     type Future = HttpServiceResponse<T, S, B, X, U>;
 
     fn new_service(&self, _: ()) -> Self::Future {
@@ -354,22 +344,21 @@ where
             fut_upg: self.upgrade.as_ref().map(|f| f.new_service(())),
             expect: None,
             upgrade: None,
-            on_connect: self.on_connect.clone(),
+            on_connect_ext: self.on_connect_ext.clone(),
             cfg: self.cfg.clone(),
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
 
 #[doc(hidden)]
 #[pin_project]
-pub struct HttpServiceResponse<
-    T,
-    S: ServiceFactory,
-    B,
-    X: ServiceFactory,
-    U: ServiceFactory,
-> {
+pub struct HttpServiceResponse<T, S, B, X, U>
+where
+    S: ServiceFactory<Request>,
+    X: ServiceFactory<Request>,
+    U: ServiceFactory<(Request, Framed<T, h1::Codec>)>,
+{
     #[pin]
     fut: S::Future,
     #[pin]
@@ -378,28 +367,28 @@ pub struct HttpServiceResponse<
     fut_upg: Option<U::Future>,
     expect: Option<X::Service>,
     upgrade: Option<U::Service>,
-    on_connect: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
     cfg: ServiceConfig,
-    _t: PhantomData<(T, B)>,
+    _phantom: PhantomData<B>,
 }
 
 impl<T, S, B, X, U> Future for HttpServiceResponse<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: ServiceFactory<Request = Request>,
+    S: ServiceFactory<Request>,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
-    X: ServiceFactory<Request = Request, Response = Request>,
+    X: ServiceFactory<Request, Response = Request>,
     X::Error: Into<Error>,
     X::InitError: fmt::Debug,
-    <X::Service as Service>::Future: 'static,
-    U: ServiceFactory<Request = (Request, Framed<T, h1::Codec>), Response = ()>,
+    <X::Service as Service<Request>>::Future: 'static,
+    U: ServiceFactory<(Request, Framed<T, h1::Codec>), Response = ()>,
     U::Error: fmt::Display,
     U::InitError: fmt::Debug,
-    <U::Service as Service>::Future: 'static,
+    <U::Service as Service<(Request, Framed<T, h1::Codec>)>>::Future: 'static,
 {
     type Output =
         Result<HttpServiceHandler<T, S::Service, B, X::Service, U::Service>, ()>;
@@ -422,13 +411,14 @@ where
                 .map_err(|e| log::error!("Init http service error: {:?}", e)))?;
             this = self.as_mut().project();
             *this.upgrade = Some(upgrade);
-            this.fut_ex.set(None);
+            this.fut_upg.set(None);
         }
 
         let result = ready!(this
             .fut
             .poll(cx)
             .map_err(|e| log::error!("Init http service error: {:?}", e)));
+
         Poll::Ready(result.map(|service| {
             let this = self.as_mut().project();
             HttpServiceHandler::new(
@@ -436,72 +426,91 @@ where
                 service,
                 this.expect.take().unwrap(),
                 this.upgrade.take(),
-                this.on_connect.clone(),
+                this.on_connect_ext.clone(),
             )
         }))
     }
 }
 
-/// `Service` implementation for http transport
-pub struct HttpServiceHandler<T, S: Service, B, X: Service, U: Service> {
-    srv: CloneableService<S>,
-    expect: CloneableService<X>,
-    upgrade: Option<CloneableService<U>>,
+/// `Service` implementation for HTTP transport
+pub struct HttpServiceHandler<T, S, B, X, U>
+where
+    S: Service<Request>,
+    X: Service<Request>,
+    U: Service<(Request, Framed<T, h1::Codec>)>,
+{
+    flow: Rc<HttpFlow<S, X, U>>,
     cfg: ServiceConfig,
-    on_connect: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
-    _t: PhantomData<(T, B, X)>,
+    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
+    _phantom: PhantomData<B>,
+}
+
+/// A collection of services that describe an HTTP request flow.
+pub(super) struct HttpFlow<S, X, U> {
+    pub(super) service: S,
+    pub(super) expect: X,
+    pub(super) upgrade: Option<U>,
+}
+
+impl<S, X, U> HttpFlow<S, X, U> {
+    pub(super) fn new(service: S, expect: X, upgrade: Option<U>) -> Rc<Self> {
+        Rc::new(Self {
+            service,
+            expect,
+            upgrade,
+        })
+    }
 }
 
 impl<T, S, B, X, U> HttpServiceHandler<T, S, B, X, U>
 where
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error> + 'static,
     S::Future: 'static,
     S::Response: Into<Response<B>> + 'static,
     B: MessageBody + 'static,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, h1::Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, h1::Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
     fn new(
         cfg: ServiceConfig,
-        srv: S,
+        service: S,
         expect: X,
         upgrade: Option<U>,
-        on_connect: Option<rc::Rc<dyn Fn(&T) -> Box<dyn DataFactory>>>,
+        on_connect_ext: Option<Rc<ConnectCallback<T>>>,
     ) -> HttpServiceHandler<T, S, B, X, U> {
         HttpServiceHandler {
             cfg,
-            on_connect,
-            srv: CloneableService::new(srv),
-            expect: CloneableService::new(expect),
-            upgrade: upgrade.map(CloneableService::new),
-            _t: PhantomData,
+            on_connect_ext,
+            flow: HttpFlow::new(service, expect, upgrade),
+            _phantom: PhantomData,
         }
     }
 }
 
-impl<T, S, B, X, U> Service for HttpServiceHandler<T, S, B, X, U>
+impl<T, S, B, X, U> Service<(T, Protocol, Option<net::SocketAddr>)>
+    for HttpServiceHandler<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error> + 'static,
     S::Future: 'static,
     S::Response: Into<Response<B>> + 'static,
     B: MessageBody + 'static,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, h1::Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, h1::Codec>), Response = ()>,
     U::Error: fmt::Display + Into<Error>,
 {
-    type Request = (T, Protocol, Option<net::SocketAddr>);
     type Response = ();
     type Error = DispatchError;
     type Future = HttpServiceHandlerResponse<T, S, B, X, U>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         let ready = self
+            .flow
             .expect
             .poll_ready(cx)
             .map_err(|e| {
@@ -512,7 +521,8 @@ where
             .is_ready();
 
         let ready = self
-            .srv
+            .flow
+            .service
             .poll_ready(cx)
             .map_err(|e| {
                 let e = e.into();
@@ -522,7 +532,7 @@ where
             .is_ready()
             && ready;
 
-        let ready = if let Some(ref mut upg) = self.upgrade {
+        let ready = if let Some(ref upg) = self.flow.upgrade {
             upg.poll_ready(cx)
                 .map_err(|e| {
                     let e = e.into();
@@ -542,34 +552,35 @@ where
         }
     }
 
-    fn call(&mut self, (io, proto, peer_addr): Self::Request) -> Self::Future {
-        let on_connect = if let Some(ref on_connect) = self.on_connect {
-            Some(on_connect(&io))
-        } else {
-            None
-        };
+    fn call(
+        &self,
+        (io, proto, peer_addr): (T, Protocol, Option<net::SocketAddr>),
+    ) -> Self::Future {
+        let on_connect_data =
+            OnConnectData::from_io(&io, self.on_connect_ext.as_deref());
 
         match proto {
             Protocol::Http2 => HttpServiceHandlerResponse {
                 state: State::H2Handshake(Some((
                     server::handshake(io),
                     self.cfg.clone(),
-                    self.srv.clone(),
-                    on_connect,
+                    self.flow.clone(),
+                    on_connect_data,
                     peer_addr,
                 ))),
             },
+
             Protocol::Http1 => HttpServiceHandlerResponse {
                 state: State::H1(h1::Dispatcher::new(
                     io,
                     self.cfg.clone(),
-                    self.srv.clone(),
-                    self.expect.clone(),
-                    self.upgrade.clone(),
-                    on_connect,
+                    self.flow.clone(),
+                    on_connect_data,
                     peer_addr,
                 )),
             },
+
+            proto => unimplemented!("Unsupported HTTP version: {:?}.", proto),
         }
     }
 }
@@ -577,24 +588,24 @@ where
 #[pin_project(project = StateProj)]
 enum State<T, S, B, X, U>
 where
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Future: 'static,
     S::Error: Into<Error>,
     T: AsyncRead + AsyncWrite + Unpin,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, h1::Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, h1::Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
     H1(#[pin] h1::Dispatcher<T, S, B, X, U>),
-    H2(#[pin] Dispatcher<T, S, B>),
+    H2(#[pin] Dispatcher<T, S, B, X, U>),
     H2Handshake(
         Option<(
             Handshake<T, Bytes>,
             ServiceConfig,
-            CloneableService<S>,
-            Option<Box<dyn DataFactory>>,
+            Rc<HttpFlow<S, X, U>>,
+            OnConnectData,
             Option<net::SocketAddr>,
         )>,
     ),
@@ -604,14 +615,14 @@ where
 pub struct HttpServiceHandlerResponse<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error> + 'static,
     S::Future: 'static,
     S::Response: Into<Response<B>> + 'static,
     B: MessageBody + 'static,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, h1::Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, h1::Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
     #[pin]
@@ -621,60 +632,42 @@ where
 impl<T, S, B, X, U> Future for HttpServiceHandlerResponse<T, S, B, X, U>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
+    S: Service<Request>,
     S::Error: Into<Error> + 'static,
     S::Future: 'static,
     S::Response: Into<Response<B>> + 'static,
     B: MessageBody,
-    X: Service<Request = Request, Response = Request>,
+    X: Service<Request, Response = Request>,
     X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, h1::Codec>), Response = ()>,
+    U: Service<(Request, Framed<T, h1::Codec>), Response = ()>,
     U::Error: fmt::Display,
 {
     type Output = Result<(), DispatchError>;
 
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        self.project().state.poll(cx)
-    }
-}
-
-impl<T, S, B, X, U> State<T, S, B, X, U>
-where
-    T: AsyncRead + AsyncWrite + Unpin,
-    S: Service<Request = Request>,
-    S::Error: Into<Error> + 'static,
-    S::Response: Into<Response<B>> + 'static,
-    B: MessageBody + 'static,
-    X: Service<Request = Request, Response = Request>,
-    X::Error: Into<Error>,
-    U: Service<Request = (Request, Framed<T, h1::Codec>), Response = ()>,
-    U::Error: fmt::Display,
-{
-    fn poll(
-        mut self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Result<(), DispatchError>> {
-        match self.as_mut().project() {
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        match self.as_mut().project().state.project() {
             StateProj::H1(disp) => disp.poll(cx),
             StateProj::H2(disp) => disp.poll(cx),
-            StateProj::H2Handshake(ref mut data) => {
-                let conn = if let Some(ref mut item) = data {
-                    match Pin::new(&mut item.0).poll(cx) {
-                        Poll::Ready(Ok(conn)) => conn,
-                        Poll::Ready(Err(err)) => {
-                            trace!("H2 handshake error: {}", err);
-                            return Poll::Ready(Err(err.into()));
-                        }
-                        Poll::Pending => return Poll::Pending,
+            StateProj::H2Handshake(data) => {
+                match ready!(Pin::new(&mut data.as_mut().unwrap().0).poll(cx)) {
+                    Ok(conn) => {
+                        let (_, cfg, srv, on_connect_data, peer_addr) =
+                            data.take().unwrap();
+                        self.as_mut().project().state.set(State::H2(Dispatcher::new(
+                            srv,
+                            conn,
+                            on_connect_data,
+                            cfg,
+                            None,
+                            peer_addr,
+                        )));
+                        self.poll(cx)
                     }
-                } else {
-                    panic!()
-                };
-                let (_, cfg, srv, on_connect, peer_addr) = data.take().unwrap();
-                self.set(State::H2(Dispatcher::new(
-                    srv, conn, on_connect, cfg, None, peer_addr,
-                )));
-                self.poll(cx)
+                    Err(err) => {
+                        trace!("H2 handshake error: {}", err);
+                        Poll::Ready(Err(err.into()))
+                    }
+                }
             }
         }
     }
diff --git a/actix-http/src/test.rs b/actix-http/src/test.rs
index b79f5a73c..870a656df 100644
--- a/actix-http/src/test.rs
+++ b/actix-http/src/test.rs
@@ -1,20 +1,28 @@
-//! Test Various helpers for Actix applications to use during testing.
-use std::convert::TryFrom;
-use std::io::{self, Read, Write};
-use std::pin::Pin;
-use std::str::FromStr;
-use std::task::{Context, Poll};
+//! Various testing helpers for use in internal and app tests.
 
-use actix_codec::{AsyncRead, AsyncWrite};
+use std::{
+    cell::{Ref, RefCell},
+    io::{self, Read, Write},
+    pin::Pin,
+    rc::Rc,
+    str::FromStr,
+    task::{Context, Poll},
+};
+
+use actix_codec::{AsyncRead, AsyncWrite, ReadBuf};
 use bytes::{Bytes, BytesMut};
-use http::header::{self, HeaderName, HeaderValue};
-use http::{Error as HttpError, Method, Uri, Version};
+use http::{Method, Uri, Version};
 
-use crate::cookie::{Cookie, CookieJar};
-use crate::header::HeaderMap;
-use crate::header::{Header, IntoHeaderValue};
-use crate::payload::Payload;
-use crate::Request;
+#[cfg(feature = "cookies")]
+use crate::{
+    cookie::{Cookie, CookieJar},
+    header::{self, HeaderValue},
+};
+use crate::{
+    header::{HeaderMap, IntoHeaderPair},
+    payload::Payload,
+    Request,
+};
 
 /// Test `Request` builder
 ///
@@ -31,7 +39,7 @@ use crate::Request;
 ///     }
 /// }
 ///
-/// let resp = TestRequest::with_header("content-type", "text/plain")
+/// let resp = TestRequest::default().insert_header("content-type", "text/plain")
 ///     .run(&index)
 ///     .unwrap();
 /// assert_eq!(resp.status(), StatusCode::OK);
@@ -46,6 +54,7 @@ struct Inner {
     method: Method,
     uri: Uri,
     headers: HeaderMap,
+    #[cfg(feature = "cookies")]
     cookies: CookieJar,
     payload: Option<Payload>,
 }
@@ -57,6 +66,7 @@ impl Default for TestRequest {
             uri: Uri::from_str("/").unwrap(),
             version: Version::HTTP_11,
             headers: HeaderMap::new(),
+            #[cfg(feature = "cookies")]
             cookies: CookieJar::new(),
             payload: None,
         }))
@@ -64,76 +74,74 @@ impl Default for TestRequest {
 }
 
 impl TestRequest {
-    /// Create TestRequest and set request uri
+    /// Create a default TestRequest and then set its URI.
     pub fn with_uri(path: &str) -> TestRequest {
         TestRequest::default().uri(path).take()
     }
 
-    /// Create TestRequest and set header
-    pub fn with_hdr<H: Header>(hdr: H) -> TestRequest {
-        TestRequest::default().set(hdr).take()
-    }
-
-    /// Create TestRequest and set header
-    pub fn with_header<K, V>(key: K, value: V) -> TestRequest
-    where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
-    {
-        TestRequest::default().header(key, value).take()
-    }
-
-    /// Set HTTP version of this request
+    /// Set HTTP version of this request.
     pub fn version(&mut self, ver: Version) -> &mut Self {
         parts(&mut self.0).version = ver;
         self
     }
 
-    /// Set HTTP method of this request
+    /// Set HTTP method of this request.
     pub fn method(&mut self, meth: Method) -> &mut Self {
         parts(&mut self.0).method = meth;
         self
     }
 
-    /// Set HTTP Uri of this request
+    /// Set URI of this request.
+    ///
+    /// # Panics
+    /// If provided URI is invalid.
     pub fn uri(&mut self, path: &str) -> &mut Self {
         parts(&mut self.0).uri = Uri::from_str(path).unwrap();
         self
     }
 
-    /// Set a header
-    pub fn set<H: Header>(&mut self, hdr: H) -> &mut Self {
-        if let Ok(value) = hdr.try_into() {
-            parts(&mut self.0).headers.append(H::name(), value);
-            return self;
-        }
-        panic!("Can not set header");
-    }
-
-    /// Set a header
-    pub fn header<K, V>(&mut self, key: K, value: V) -> &mut Self
+    /// Insert a header, replacing any that were set with an equivalent field name.
+    pub fn insert_header<H>(&mut self, header: H) -> &mut Self
     where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
+        H: IntoHeaderPair,
     {
-        if let Ok(key) = HeaderName::try_from(key) {
-            if let Ok(value) = value.try_into() {
-                parts(&mut self.0).headers.append(key, value);
-                return self;
+        match header.try_into_header_pair() {
+            Ok((key, value)) => {
+                parts(&mut self.0).headers.insert(key, value);
+            }
+            Err(err) => {
+                panic!("Error inserting test header: {}.", err.into());
             }
         }
-        panic!("Can not create header");
+
+        self
     }
 
-    /// Set cookie for this request
+    /// Append a header, keeping any that were set with an equivalent field name.
+    pub fn append_header<H>(&mut self, header: H) -> &mut Self
+    where
+        H: IntoHeaderPair,
+    {
+        match header.try_into_header_pair() {
+            Ok((key, value)) => {
+                parts(&mut self.0).headers.append(key, value);
+            }
+            Err(err) => {
+                panic!("Error inserting test header: {}.", err.into());
+            }
+        }
+
+        self
+    }
+
+    /// Set cookie for this request.
+    #[cfg(feature = "cookies")]
     pub fn cookie<'a>(&mut self, cookie: Cookie<'a>) -> &mut Self {
         parts(&mut self.0).cookies.add(cookie.into_owned());
         self
     }
 
-    /// Set request payload
+    /// Set request payload.
     pub fn set_payload<B: Into<Bytes>>(&mut self, data: B) -> &mut Self {
         let mut payload = crate::h1::Payload::empty();
         payload.unread_data(data.into());
@@ -145,7 +153,7 @@ impl TestRequest {
         TestRequest(self.0.take())
     }
 
-    /// Complete request creation and generate `Request` instance
+    /// Complete request creation and generate `Request` instance.
     pub fn finish(&mut self) -> Request {
         let inner = self.0.take().expect("cannot reuse test request builder");
 
@@ -161,17 +169,20 @@ impl TestRequest {
         head.version = inner.version;
         head.headers = inner.headers;
 
-        let cookie: String = inner
-            .cookies
-            .delta()
-            // ensure only name=value is written to cookie header
-            .map(|c| Cookie::new(c.name(), c.value()).encoded().to_string())
-            .collect::<Vec<_>>()
-            .join("; ");
+        #[cfg(feature = "cookies")]
+        {
+            let cookie: String = inner
+                .cookies
+                .delta()
+                // ensure only name=value is written to cookie header
+                .map(|c| Cookie::new(c.name(), c.value()).encoded().to_string())
+                .collect::<Vec<_>>()
+                .join("; ");
 
-        if !cookie.is_empty() {
-            head.headers
-                .insert(header::COOKIE, HeaderValue::from_str(&cookie).unwrap());
+            if !cookie.is_empty() {
+                head.headers
+                    .insert(header::COOKIE, HeaderValue::from_str(&cookie).unwrap());
+            }
         }
 
         req
@@ -183,7 +194,7 @@ fn parts(parts: &mut Option<Inner>) -> &mut Inner {
     parts.as_mut().expect("cannot reuse test request builder")
 }
 
-/// Async io buffer
+/// Async I/O test buffer.
 pub struct TestBuffer {
     pub read_buf: BytesMut,
     pub write_buf: BytesMut,
@@ -191,24 +202,24 @@ pub struct TestBuffer {
 }
 
 impl TestBuffer {
-    /// Create new TestBuffer instance
-    pub fn new<T>(data: T) -> TestBuffer
+    /// Create new `TestBuffer` instance with initial read buffer.
+    pub fn new<T>(data: T) -> Self
     where
-        BytesMut: From<T>,
+        T: Into<BytesMut>,
     {
-        TestBuffer {
-            read_buf: BytesMut::from(data),
+        Self {
+            read_buf: data.into(),
             write_buf: BytesMut::new(),
             err: None,
         }
     }
 
-    /// Create new empty TestBuffer instance
-    pub fn empty() -> TestBuffer {
-        TestBuffer::new("")
+    /// Create new empty `TestBuffer` instance.
+    pub fn empty() -> Self {
+        Self::new("")
     }
 
-    /// Add extra data to read buffer.
+    /// Add data to read buffer.
     pub fn extend_read_buf<T: AsRef<[u8]>>(&mut self, data: T) {
         self.read_buf.extend_from_slice(data.as_ref())
     }
@@ -236,6 +247,7 @@ impl io::Write for TestBuffer {
         self.write_buf.extend(buf);
         Ok(buf.len())
     }
+
     fn flush(&mut self) -> io::Result<()> {
         Ok(())
     }
@@ -245,9 +257,11 @@ impl AsyncRead for TestBuffer {
     fn poll_read(
         self: Pin<&mut Self>,
         _: &mut Context<'_>,
-        buf: &mut [u8],
-    ) -> Poll<io::Result<usize>> {
-        Poll::Ready(self.get_mut().read(buf))
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
+        let dst = buf.initialize_unfilled();
+        let res = self.get_mut().read(dst).map(|n| buf.advance(n));
+        Poll::Ready(res)
     }
 }
 
@@ -268,3 +282,117 @@ impl AsyncWrite for TestBuffer {
         Poll::Ready(Ok(()))
     }
 }
+
+/// Async I/O test buffer with ability to incrementally add to the read buffer.
+#[derive(Clone)]
+pub struct TestSeqBuffer(Rc<RefCell<TestSeqInner>>);
+
+impl TestSeqBuffer {
+    /// Create new `TestBuffer` instance with initial read buffer.
+    pub fn new<T>(data: T) -> Self
+    where
+        T: Into<BytesMut>,
+    {
+        Self(Rc::new(RefCell::new(TestSeqInner {
+            read_buf: data.into(),
+            write_buf: BytesMut::new(),
+            err: None,
+        })))
+    }
+
+    /// Create new empty `TestBuffer` instance.
+    pub fn empty() -> Self {
+        Self::new("")
+    }
+
+    pub fn read_buf(&self) -> Ref<'_, BytesMut> {
+        Ref::map(self.0.borrow(), |inner| &inner.read_buf)
+    }
+
+    pub fn write_buf(&self) -> Ref<'_, BytesMut> {
+        Ref::map(self.0.borrow(), |inner| &inner.write_buf)
+    }
+
+    pub fn err(&self) -> Ref<'_, Option<io::Error>> {
+        Ref::map(self.0.borrow(), |inner| &inner.err)
+    }
+
+    /// Add data to read buffer.
+    pub fn extend_read_buf<T: AsRef<[u8]>>(&mut self, data: T) {
+        self.0
+            .borrow_mut()
+            .read_buf
+            .extend_from_slice(data.as_ref())
+    }
+}
+
+pub struct TestSeqInner {
+    read_buf: BytesMut,
+    write_buf: BytesMut,
+    err: Option<io::Error>,
+}
+
+impl io::Read for TestSeqBuffer {
+    fn read(&mut self, dst: &mut [u8]) -> Result<usize, io::Error> {
+        if self.0.borrow().read_buf.is_empty() {
+            if self.0.borrow().err.is_some() {
+                Err(self.0.borrow_mut().err.take().unwrap())
+            } else {
+                Err(io::Error::new(io::ErrorKind::WouldBlock, ""))
+            }
+        } else {
+            let size = std::cmp::min(self.0.borrow().read_buf.len(), dst.len());
+            let b = self.0.borrow_mut().read_buf.split_to(size);
+            dst[..size].copy_from_slice(&b);
+            Ok(size)
+        }
+    }
+}
+
+impl io::Write for TestSeqBuffer {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.0.borrow_mut().write_buf.extend(buf);
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl AsyncRead for TestSeqBuffer {
+    fn poll_read(
+        self: Pin<&mut Self>,
+        _: &mut Context<'_>,
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
+        let dst = buf.initialize_unfilled();
+        let r = self.get_mut().read(dst);
+        match r {
+            Ok(n) => {
+                buf.advance(n);
+                Poll::Ready(Ok(()))
+            }
+            Err(err) if err.kind() == io::ErrorKind::WouldBlock => Poll::Pending,
+            Err(err) => Poll::Ready(Err(err)),
+        }
+    }
+}
+
+impl AsyncWrite for TestSeqBuffer {
+    fn poll_write(
+        self: Pin<&mut Self>,
+        _: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        Poll::Ready(self.get_mut().write(buf))
+    }
+
+    fn poll_flush(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Poll::Ready(Ok(()))
+    }
+
+    fn poll_shutdown(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Poll::Ready(Ok(()))
+    }
+}
diff --git a/actix-http/src/time_parser.rs b/actix-http/src/time_parser.rs
index 0d06a5867..46bf73037 100644
--- a/actix-http/src/time_parser.rs
+++ b/actix-http/src/time_parser.rs
@@ -8,35 +8,65 @@ pub fn parse_http_date(time: &str) -> Option<PrimitiveDateTime> {
 }
 
 /// Attempt to parse a `time` string as a RFC 1123 formatted date time string.
+///
+/// Eg: `Fri, 12 Feb 2021 00:14:29 GMT`
 fn try_parse_rfc_1123(time: &str) -> Option<PrimitiveDateTime> {
     time::parse(time, "%a, %d %b %Y %H:%M:%S").ok()
 }
 
 /// Attempt to parse a `time` string as a RFC 850 formatted date time string.
+///
+/// Eg: `Wednesday, 11-Jan-21 13:37:41 UTC`
 fn try_parse_rfc_850(time: &str) -> Option<PrimitiveDateTime> {
-    match PrimitiveDateTime::parse(time, "%A, %d-%b-%y %H:%M:%S") {
-        Ok(dt) => {
-            // If the `time` string contains a two-digit year, then as per RFC 2616 § 19.3,
-            // we consider the year as part of this century if it's within the next 50 years,
-            // otherwise we consider as part of the previous century.
-            let now = OffsetDateTime::now_utc();
-            let century_start_year = (now.year() / 100) * 100;
-            let mut expanded_year = century_start_year + dt.year();
+    let dt = PrimitiveDateTime::parse(time, "%A, %d-%b-%y %H:%M:%S").ok()?;
 
-            if expanded_year > now.year() + 50 {
-                expanded_year -= 100;
-            }
+    // If the `time` string contains a two-digit year, then as per RFC 2616 § 19.3,
+    // we consider the year as part of this century if it's within the next 50 years,
+    // otherwise we consider as part of the previous century.
 
-            match Date::try_from_ymd(expanded_year, dt.month(), dt.day()) {
-                Ok(date) => Some(PrimitiveDateTime::new(date, dt.time())),
-                Err(_) => None,
-            }
-        }
-        Err(_) => None,
+    let now = OffsetDateTime::now_utc();
+    let century_start_year = (now.year() / 100) * 100;
+    let mut expanded_year = century_start_year + dt.year();
+
+    if expanded_year > now.year() + 50 {
+        expanded_year -= 100;
     }
+
+    let date = Date::try_from_ymd(expanded_year, dt.month(), dt.day()).ok()?;
+    Some(PrimitiveDateTime::new(date, dt.time()))
 }
 
 /// Attempt to parse a `time` string using ANSI C's `asctime` format.
+///
+/// Eg: `Wed Feb 13 15:46:11 2013`
 fn try_parse_asctime(time: &str) -> Option<PrimitiveDateTime> {
     time::parse(time, "%a %b %_d %H:%M:%S %Y").ok()
 }
+
+#[cfg(test)]
+mod tests {
+    use time::{date, time};
+
+    use super::*;
+
+    #[test]
+    fn test_rfc_850_year_shift() {
+        let date = try_parse_rfc_850("Friday, 19-Nov-82 16:14:55 EST").unwrap();
+        assert_eq!(date, date!(1982 - 11 - 19).with_time(time!(16:14:55)));
+
+        let date = try_parse_rfc_850("Wednesday, 11-Jan-62 13:37:41 EST").unwrap();
+        assert_eq!(date, date!(2062 - 01 - 11).with_time(time!(13:37:41)));
+
+        let date = try_parse_rfc_850("Wednesday, 11-Jan-21 13:37:41 EST").unwrap();
+        assert_eq!(date, date!(2021 - 01 - 11).with_time(time!(13:37:41)));
+
+        let date = try_parse_rfc_850("Wednesday, 11-Jan-23 13:37:41 EST").unwrap();
+        assert_eq!(date, date!(2023 - 01 - 11).with_time(time!(13:37:41)));
+
+        let date = try_parse_rfc_850("Wednesday, 11-Jan-99 13:37:41 EST").unwrap();
+        assert_eq!(date, date!(1999 - 01 - 11).with_time(time!(13:37:41)));
+
+        let date = try_parse_rfc_850("Wednesday, 11-Jan-00 13:37:41 EST").unwrap();
+        assert_eq!(date, date!(2000 - 01 - 11).with_time(time!(13:37:41)));
+    }
+}
diff --git a/actix-http/src/ws/codec.rs b/actix-http/src/ws/codec.rs
index 7c9628b1a..54d850854 100644
--- a/actix-http/src/ws/codec.rs
+++ b/actix-http/src/ws/codec.rs
@@ -1,47 +1,60 @@
 use actix_codec::{Decoder, Encoder};
+use bitflags::bitflags;
 use bytes::{Bytes, BytesMut};
+use bytestring::ByteString;
 
 use super::frame::Parser;
 use super::proto::{CloseReason, OpCode};
 use super::ProtocolError;
 
-/// `WebSocket` Message
+/// A WebSocket message.
 #[derive(Debug, PartialEq)]
 pub enum Message {
-    /// Text message
-    Text(String),
-    /// Binary message
+    /// Text message.
+    Text(ByteString),
+
+    /// Binary message.
     Binary(Bytes),
-    /// Continuation
+
+    /// Continuation.
     Continuation(Item),
-    /// Ping message
+
+    /// Ping message.
     Ping(Bytes),
-    /// Pong message
+
+    /// Pong message.
     Pong(Bytes),
-    /// Close message with optional reason
+
+    /// Close message with optional reason.
     Close(Option<CloseReason>),
-    /// No-op. Useful for actix-net services
+
+    /// No-op. Useful for low-level services.
     Nop,
 }
 
-/// `WebSocket` frame
+/// A WebSocket frame.
 #[derive(Debug, PartialEq)]
 pub enum Frame {
-    /// Text frame, codec does not verify utf8 encoding
+    /// Text frame. Note that the codec does not validate UTF-8 encoding.
     Text(Bytes),
-    /// Binary frame
+
+    /// Binary frame.
     Binary(Bytes),
-    /// Continuation
+
+    /// Continuation.
     Continuation(Item),
-    /// Ping message
+
+    /// Ping message.
     Ping(Bytes),
-    /// Pong message
+
+    /// Pong message.
     Pong(Bytes),
-    /// Close message with optional reason
+
+    /// Close message with optional reason.
     Close(Option<CloseReason>),
 }
 
-/// `WebSocket` continuation item
+/// A WebSocket continuation item.
 #[derive(Debug, PartialEq)]
 pub enum Item {
     FirstText(Bytes),
@@ -51,13 +64,13 @@ pub enum Item {
 }
 
 #[derive(Debug, Copy, Clone)]
-/// WebSockets protocol codec
+/// WebSocket protocol codec.
 pub struct Codec {
     flags: Flags,
     max_size: usize,
 }
 
-bitflags::bitflags! {
+bitflags! {
     struct Flags: u8 {
         const SERVER         = 0b0000_0001;
         const CONTINUATION   = 0b0000_0010;
@@ -66,7 +79,7 @@ bitflags::bitflags! {
 }
 
 impl Codec {
-    /// Create new websocket frames decoder
+    /// Create new WebSocket frames decoder.
     pub fn new() -> Codec {
         Codec {
             max_size: 65_536,
@@ -74,9 +87,9 @@ impl Codec {
         }
     }
 
-    /// Set max frame size
+    /// Set max frame size.
     ///
-    /// By default max size is set to 64kb
+    /// By default max size is set to 64kB.
     pub fn max_size(mut self, size: usize) -> Self {
         self.max_size = size;
         self
@@ -184,7 +197,7 @@ impl Encoder<Message> for Codec {
                     }
                 }
             },
-            Message::Nop => (),
+            Message::Nop => {}
         }
         Ok(())
     }
diff --git a/actix-http/src/ws/dispatcher.rs b/actix-http/src/ws/dispatcher.rs
index b114217a0..7be7cf637 100644
--- a/actix-http/src/ws/dispatcher.rs
+++ b/actix-http/src/ws/dispatcher.rs
@@ -11,7 +11,7 @@ use super::{Codec, Frame, Message};
 #[pin_project::pin_project]
 pub struct Dispatcher<S, T>
 where
-    S: Service<Request = Frame, Response = Message> + 'static,
+    S: Service<Frame, Response = Message> + 'static,
     T: AsyncRead + AsyncWrite,
 {
     #[pin]
@@ -21,17 +21,17 @@ where
 impl<S, T> Dispatcher<S, T>
 where
     T: AsyncRead + AsyncWrite,
-    S: Service<Request = Frame, Response = Message>,
+    S: Service<Frame, Response = Message>,
     S::Future: 'static,
     S::Error: 'static,
 {
-    pub fn new<F: IntoService<S>>(io: T, service: F) -> Self {
+    pub fn new<F: IntoService<S, Frame>>(io: T, service: F) -> Self {
         Dispatcher {
             inner: InnerDispatcher::new(Framed::new(io, Codec::new()), service),
         }
     }
 
-    pub fn with<F: IntoService<S>>(framed: Framed<T, Codec>, service: F) -> Self {
+    pub fn with<F: IntoService<S, Frame>>(framed: Framed<T, Codec>, service: F) -> Self {
         Dispatcher {
             inner: InnerDispatcher::new(framed, service),
         }
@@ -41,7 +41,7 @@ where
 impl<S, T> Future for Dispatcher<S, T>
 where
     T: AsyncRead + AsyncWrite,
-    S: Service<Request = Frame, Response = Message>,
+    S: Service<Frame, Response = Message>,
     S::Future: 'static,
     S::Error: 'static,
 {
diff --git a/actix-http/src/ws/frame.rs b/actix-http/src/ws/frame.rs
index 0598a9b4e..46edf5d85 100644
--- a/actix-http/src/ws/frame.rs
+++ b/actix-http/src/ws/frame.rs
@@ -7,7 +7,7 @@ use crate::ws::mask::apply_mask;
 use crate::ws::proto::{CloseCode, CloseReason, OpCode};
 use crate::ws::ProtocolError;
 
-/// A struct representing a `WebSocket` frame.
+/// A struct representing a WebSocket frame.
 #[derive(Debug)]
 pub struct Parser;
 
@@ -16,7 +16,8 @@ impl Parser {
         src: &[u8],
         server: bool,
         max_size: usize,
-    ) -> Result<Option<(usize, bool, OpCode, usize, Option<u32>)>, ProtocolError> {
+    ) -> Result<Option<(usize, bool, OpCode, usize, Option<[u8; 4]>)>, ProtocolError>
+    {
         let chunk_len = src.len();
 
         let mut idx = 2;
@@ -77,9 +78,10 @@ impl Parser {
                 return Ok(None);
             }
 
-            let mask =
-                u32::from_le_bytes(TryFrom::try_from(&src[idx..idx + 4]).unwrap());
+            let mask = TryFrom::try_from(&src[idx..idx + 4]).unwrap();
+
             idx += 4;
+
             Some(mask)
         } else {
             None
@@ -125,7 +127,7 @@ impl Parser {
                 debug!("Received close frame with payload length exceeding 125. Morphing to protocol close frame.");
                 return Ok(Some((true, OpCode::Close, None)));
             }
-            _ => (),
+            _ => {}
         }
 
         // unmask
@@ -187,8 +189,8 @@ impl Parser {
         };
 
         if mask {
-            let mask = rand::random::<u32>();
-            dst.put_u32_le(mask);
+            let mask = rand::random::<[u8; 4]>();
+            dst.put_slice(mask.as_ref());
             dst.put_slice(payload.as_ref());
             let pos = dst.len() - payload_len;
             apply_mask(&mut dst[pos..], mask);
diff --git a/actix-http/src/ws/mask.rs b/actix-http/src/ws/mask.rs
index 726b1a4a1..276ca4a85 100644
--- a/actix-http/src/ws/mask.rs
+++ b/actix-http/src/ws/mask.rs
@@ -1,125 +1,57 @@
 //! This is code from [Tungstenite project](https://github.com/snapview/tungstenite-rs)
-#![allow(clippy::cast_ptr_alignment)]
-use std::ptr::copy_nonoverlapping;
-use std::slice;
 
-// Holds a slice guaranteed to be shorter than 8 bytes
-struct ShortSlice<'a>(&'a mut [u8]);
+/// Mask/unmask a frame.
+#[inline]
+pub fn apply_mask(buf: &mut [u8], mask: [u8; 4]) {
+    apply_mask_fast32(buf, mask)
+}
 
-impl<'a> ShortSlice<'a> {
-    /// # Safety
-    /// Given slice must be shorter than 8 bytes.
-    unsafe fn new(slice: &'a mut [u8]) -> Self {
-        // Sanity check for debug builds
-        debug_assert!(slice.len() < 8);
-        ShortSlice(slice)
-    }
-    fn len(&self) -> usize {
-        self.0.len()
+/// A safe unoptimized mask application.
+#[inline]
+fn apply_mask_fallback(buf: &mut [u8], mask: [u8; 4]) {
+    for (i, byte) in buf.iter_mut().enumerate() {
+        *byte ^= mask[i & 3];
     }
 }
 
-/// Faster version of `apply_mask()` which operates on 8-byte blocks.
+/// Faster version of `apply_mask()` which operates on 4-byte blocks.
 #[inline]
-#[allow(clippy::cast_lossless)]
-pub(crate) fn apply_mask(buf: &mut [u8], mask_u32: u32) {
-    // Extend the mask to 64 bits
-    let mut mask_u64 = ((mask_u32 as u64) << 32) | (mask_u32 as u64);
-    // Split the buffer into three segments
-    let (head, mid, tail) = align_buf(buf);
+pub fn apply_mask_fast32(buf: &mut [u8], mask: [u8; 4]) {
+    let mask_u32 = u32::from_ne_bytes(mask);
 
-    // Initial unaligned segment
-    let head_len = head.len();
-    if head_len > 0 {
-        xor_short(head, mask_u64);
+    // SAFETY:
+    //
+    // buf is a valid slice borrowed mutably from bytes::BytesMut.
+    //
+    // un aligned prefix and suffix would be mask/unmask per byte.
+    // proper aligned middle slice goes into fast path and operates on 4-byte blocks.
+    let (mut prefix, words, mut suffix) = unsafe { buf.align_to_mut::<u32>() };
+    apply_mask_fallback(&mut prefix, mask);
+    let head = prefix.len() & 3;
+    let mask_u32 = if head > 0 {
         if cfg!(target_endian = "big") {
-            mask_u64 = mask_u64.rotate_left(8 * head_len as u32);
+            mask_u32.rotate_left(8 * head as u32)
         } else {
-            mask_u64 = mask_u64.rotate_right(8 * head_len as u32);
+            mask_u32.rotate_right(8 * head as u32)
         }
-    }
-    // Aligned segment
-    for v in mid {
-        *v ^= mask_u64;
-    }
-    // Final unaligned segment
-    if tail.len() > 0 {
-        xor_short(tail, mask_u64);
-    }
-}
-
-// TODO: copy_nonoverlapping here compiles to call memcpy. While it is not so
-// inefficient, it could be done better. The compiler does not understand that
-// a `ShortSlice` must be smaller than a u64.
-#[inline]
-#[allow(clippy::needless_pass_by_value)]
-fn xor_short(buf: ShortSlice<'_>, mask: u64) {
-    // SAFETY: we know that a `ShortSlice` fits in a u64
-    unsafe {
-        let (ptr, len) = (buf.0.as_mut_ptr(), buf.0.len());
-        let mut b: u64 = 0;
-        #[allow(trivial_casts)]
-        copy_nonoverlapping(ptr, &mut b as *mut _ as *mut u8, len);
-        b ^= mask;
-        #[allow(trivial_casts)]
-        copy_nonoverlapping(&b as *const _ as *const u8, ptr, len);
-    }
-}
-
-/// # Safety
-/// Caller must ensure the buffer has the correct size and alignment.
-#[inline]
-unsafe fn cast_slice(buf: &mut [u8]) -> &mut [u64] {
-    // Assert correct size and alignment in debug builds
-    debug_assert!(buf.len().trailing_zeros() >= 3);
-    debug_assert!((buf.as_ptr() as usize).trailing_zeros() >= 3);
-
-    slice::from_raw_parts_mut(buf.as_mut_ptr() as *mut u64, buf.len() >> 3)
-}
-
-// Splits a slice into three parts: an unaligned short head and tail, plus an aligned
-// u64 mid section.
-#[inline]
-fn align_buf(buf: &mut [u8]) -> (ShortSlice<'_>, &mut [u64], ShortSlice<'_>) {
-    let start_ptr = buf.as_ptr() as usize;
-    let end_ptr = start_ptr + buf.len();
-
-    // Round *up* to next aligned boundary for start
-    let start_aligned = (start_ptr + 7) & !0x7;
-    // Round *down* to last aligned boundary for end
-    let end_aligned = end_ptr & !0x7;
-
-    if end_aligned >= start_aligned {
-        // We have our three segments (head, mid, tail)
-        let (tmp, tail) = buf.split_at_mut(end_aligned - start_ptr);
-        let (head, mid) = tmp.split_at_mut(start_aligned - start_ptr);
-
-        // SAFETY: we know the middle section is correctly aligned, and the outer
-        // sections are smaller than 8 bytes
-        unsafe { (ShortSlice::new(head), cast_slice(mid), ShortSlice(tail)) }
     } else {
-        // We didn't cross even one aligned boundary!
-
-        // SAFETY: The outer sections are smaller than 8 bytes
-        unsafe { (ShortSlice::new(buf), &mut [], ShortSlice::new(&mut [])) }
+        mask_u32
+    };
+    for word in words.iter_mut() {
+        *word ^= mask_u32;
     }
+    apply_mask_fallback(&mut suffix, mask_u32.to_ne_bytes());
 }
 
 #[cfg(test)]
 mod tests {
-    use super::apply_mask;
-
-    /// A safe unoptimized mask application.
-    fn apply_mask_fallback(buf: &mut [u8], mask: &[u8; 4]) {
-        for (i, byte) in buf.iter_mut().enumerate() {
-            *byte ^= mask[i & 3];
-        }
-    }
+    use super::*;
 
+    // legacy test from old apply mask test. kept for now for back compat test.
+    // TODO: remove it and favor the other test.
     #[test]
-    fn test_apply_mask() {
+    fn test_apply_mask_legacy() {
         let mask = [0x6d, 0xb6, 0xb2, 0x80];
-        let mask_u32 = u32::from_le_bytes(mask);
 
         let unmasked = vec![
             0xf3, 0x00, 0x01, 0x02, 0x03, 0x80, 0x81, 0x82, 0xff, 0xfe, 0x00, 0x17,
@@ -129,10 +61,10 @@ mod tests {
         // Check masking with proper alignment.
         {
             let mut masked = unmasked.clone();
-            apply_mask_fallback(&mut masked, &mask);
+            apply_mask_fallback(&mut masked, mask);
 
             let mut masked_fast = unmasked.clone();
-            apply_mask(&mut masked_fast, mask_u32);
+            apply_mask(&mut masked_fast, mask);
 
             assert_eq!(masked, masked_fast);
         }
@@ -140,12 +72,38 @@ mod tests {
         // Check masking without alignment.
         {
             let mut masked = unmasked.clone();
-            apply_mask_fallback(&mut masked[1..], &mask);
+            apply_mask_fallback(&mut masked[1..], mask);
 
             let mut masked_fast = unmasked;
-            apply_mask(&mut masked_fast[1..], mask_u32);
+            apply_mask(&mut masked_fast[1..], mask);
 
             assert_eq!(masked, masked_fast);
         }
     }
+
+    #[test]
+    fn test_apply_mask() {
+        let mask = [0x6d, 0xb6, 0xb2, 0x80];
+        let unmasked = vec![
+            0xf3, 0x00, 0x01, 0x02, 0x03, 0x80, 0x81, 0x82, 0xff, 0xfe, 0x00, 0x17,
+            0x74, 0xf9, 0x12, 0x03,
+        ];
+
+        for data_len in 0..=unmasked.len() {
+            let unmasked = &unmasked[0..data_len];
+            // Check masking with different alignment.
+            for off in 0..=3 {
+                if unmasked.len() < off {
+                    continue;
+                }
+                let mut masked = unmasked.to_vec();
+                apply_mask_fallback(&mut masked[off..], mask);
+
+                let mut masked_fast = unmasked.to_vec();
+                apply_mask_fast32(&mut masked_fast[off..], mask);
+
+                assert_eq!(masked, masked_fast);
+            }
+        }
+    }
 }
diff --git a/actix-http/src/ws/mod.rs b/actix-http/src/ws/mod.rs
index 6ffdecc35..0490163d5 100644
--- a/actix-http/src/ws/mod.rs
+++ b/actix-http/src/ws/mod.rs
@@ -1,11 +1,11 @@
-//! WebSocket protocol support.
+//! WebSocket protocol.
 //!
-//! To setup a `WebSocket`, first do web socket handshake then on success
-//! convert `Payload` into a `WsStream` stream and then use `WsWriter` to
-//! communicate with the peer.
+//! To setup a WebSocket, first perform the WebSocket handshake then on success convert `Payload` into a
+//! `WsStream` stream and then use `WsWriter` to communicate with the peer.
+
 use std::io;
 
-use derive_more::{Display, From};
+use derive_more::{Display, Error, From};
 use http::{header, Method, StatusCode};
 
 use crate::error::ResponseError;
@@ -23,86 +23,103 @@ pub use self::dispatcher::Dispatcher;
 pub use self::frame::Parser;
 pub use self::proto::{hash_key, CloseCode, CloseReason, OpCode};
 
-/// Websocket protocol errors
-#[derive(Debug, Display, From)]
+/// WebSocket protocol errors.
+#[derive(Debug, Display, From, Error)]
 pub enum ProtocolError {
-    /// Received an unmasked frame from client
-    #[display(fmt = "Received an unmasked frame from client")]
+    /// Received an unmasked frame from client.
+    #[display(fmt = "Received an unmasked frame from client.")]
     UnmaskedFrame,
-    /// Received a masked frame from server
-    #[display(fmt = "Received a masked frame from server")]
+
+    /// Received a masked frame from server.
+    #[display(fmt = "Received a masked frame from server.")]
     MaskedFrame,
-    /// Encountered invalid opcode
-    #[display(fmt = "Invalid opcode: {}", _0)]
-    InvalidOpcode(u8),
+
+    /// Encountered invalid opcode.
+    #[display(fmt = "Invalid opcode: {}.", _0)]
+    InvalidOpcode(#[error(not(source))] u8),
+
     /// Invalid control frame length
-    #[display(fmt = "Invalid control frame length: {}", _0)]
-    InvalidLength(usize),
-    /// Bad web socket op code
-    #[display(fmt = "Bad web socket op code")]
+    #[display(fmt = "Invalid control frame length: {}.", _0)]
+    InvalidLength(#[error(not(source))] usize),
+
+    /// Bad opcode.
+    #[display(fmt = "Bad opcode.")]
     BadOpCode,
+
     /// A payload reached size limit.
     #[display(fmt = "A payload reached size limit.")]
     Overflow,
-    /// Continuation is not started
+
+    /// Continuation is not started.
     #[display(fmt = "Continuation is not started.")]
     ContinuationNotStarted,
-    /// Received new continuation but it is already started
-    #[display(fmt = "Received new continuation but it is already started")]
+
+    /// Received new continuation but it is already started.
+    #[display(fmt = "Received new continuation but it is already started.")]
     ContinuationStarted,
-    /// Unknown continuation fragment
-    #[display(fmt = "Unknown continuation fragment.")]
-    ContinuationFragment(OpCode),
-    /// Io error
-    #[display(fmt = "io error: {}", _0)]
+
+    /// Unknown continuation fragment.
+    #[display(fmt = "Unknown continuation fragment: {}.", _0)]
+    ContinuationFragment(#[error(not(source))] OpCode),
+
+    /// I/O error.
+    #[display(fmt = "I/O error: {}", _0)]
     Io(io::Error),
 }
 
-impl std::error::Error for ProtocolError {}
-
 impl ResponseError for ProtocolError {}
 
-/// Websocket handshake errors
+/// WebSocket handshake errors
 #[derive(PartialEq, Debug, Display)]
 pub enum HandshakeError {
-    /// Only get method is allowed
-    #[display(fmt = "Method not allowed")]
+    /// Only get method is allowed.
+    #[display(fmt = "Method not allowed.")]
     GetMethodRequired,
-    /// Upgrade header if not set to websocket
-    #[display(fmt = "Websocket upgrade is expected")]
+
+    /// Upgrade header if not set to WebSocket.
+    #[display(fmt = "WebSocket upgrade is expected.")]
     NoWebsocketUpgrade,
-    /// Connection header is not set to upgrade
-    #[display(fmt = "Connection upgrade is expected")]
+
+    /// Connection header is not set to upgrade.
+    #[display(fmt = "Connection upgrade is expected.")]
     NoConnectionUpgrade,
-    /// Websocket version header is not set
-    #[display(fmt = "Websocket version header is required")]
+
+    /// WebSocket version header is not set.
+    #[display(fmt = "WebSocket version header is required.")]
     NoVersionHeader,
-    /// Unsupported websocket version
-    #[display(fmt = "Unsupported version")]
+
+    /// Unsupported WebSocket version.
+    #[display(fmt = "Unsupported version.")]
     UnsupportedVersion,
-    /// Websocket key is not set or wrong
-    #[display(fmt = "Unknown websocket key")]
+
+    /// WebSocket key is not set or wrong.
+    #[display(fmt = "Unknown websocket key.")]
     BadWebsocketKey,
 }
 
 impl ResponseError for HandshakeError {
     fn error_response(&self) -> Response {
-        match *self {
+        match self {
             HandshakeError::GetMethodRequired => Response::MethodNotAllowed()
-                .header(header::ALLOW, "GET")
+                .insert_header((header::ALLOW, "GET"))
                 .finish(),
+
             HandshakeError::NoWebsocketUpgrade => Response::BadRequest()
                 .reason("No WebSocket UPGRADE header found")
                 .finish(),
+
             HandshakeError::NoConnectionUpgrade => Response::BadRequest()
                 .reason("No CONNECTION upgrade")
                 .finish(),
+
             HandshakeError::NoVersionHeader => Response::BadRequest()
                 .reason("Websocket version header is required")
                 .finish(),
+
             HandshakeError::UnsupportedVersion => Response::BadRequest()
                 .reason("Unsupported version")
                 .finish(),
+
             HandshakeError::BadWebsocketKey => {
                 Response::BadRequest().reason("Handshake error").finish()
             }
@@ -110,26 +127,20 @@ impl ResponseError for HandshakeError {
     }
 }
 
-/// Verify `WebSocket` handshake request and create handshake response.
-// /// `protocols` is a sequence of known protocols. On successful handshake,
-// /// the returned response headers contain the first protocol in this list
-// /// which the server also knows.
+/// Verify WebSocket handshake request and create handshake response.
 pub fn handshake(req: &RequestHead) -> Result<ResponseBuilder, HandshakeError> {
     verify_handshake(req)?;
     Ok(handshake_response(req))
 }
 
-/// Verify `WebSocket` handshake request.
-// /// `protocols` is a sequence of known protocols. On successful handshake,
-// /// the returned response headers contain the first protocol in this list
-// /// which the server also knows.
+/// Verify WebSocket handshake request.
 pub fn verify_handshake(req: &RequestHead) -> Result<(), HandshakeError> {
     // WebSocket accepts only GET
     if req.method != Method::GET {
         return Err(HandshakeError::GetMethodRequired);
     }
 
-    // Check for "UPGRADE" to websocket header
+    // Check for "UPGRADE" to WebSocket header
     let has_hdr = if let Some(hdr) = req.headers().get(header::UPGRADE) {
         if let Ok(s) = hdr.to_str() {
             s.to_ascii_lowercase().contains("websocket")
@@ -170,7 +181,7 @@ pub fn verify_handshake(req: &RequestHead) -> Result<(), HandshakeError> {
     Ok(())
 }
 
-/// Create websocket handshake response
+/// Create WebSocket handshake response.
 ///
 /// This function returns handshake `Response`, ready to send to peer.
 pub fn handshake_response(req: &RequestHead) -> ResponseBuilder {
@@ -181,8 +192,8 @@ pub fn handshake_response(req: &RequestHead) -> ResponseBuilder {
 
     Response::build(StatusCode::SWITCHING_PROTOCOLS)
         .upgrade("websocket")
-        .header(header::TRANSFER_ENCODING, "chunked")
-        .header(header::SEC_WEBSOCKET_ACCEPT, key.as_str())
+        .insert_header((header::TRANSFER_ENCODING, "chunked"))
+        .insert_header((header::SEC_WEBSOCKET_ACCEPT, key))
         .take()
 }
 
@@ -197,104 +208,104 @@ mod tests {
         let req = TestRequest::default().method(Method::POST).finish();
         assert_eq!(
             HandshakeError::GetMethodRequired,
-            verify_handshake(req.head()).err().unwrap()
+            verify_handshake(req.head()).unwrap_err(),
         );
 
         let req = TestRequest::default().finish();
         assert_eq!(
             HandshakeError::NoWebsocketUpgrade,
-            verify_handshake(req.head()).err().unwrap()
+            verify_handshake(req.head()).unwrap_err(),
         );
 
         let req = TestRequest::default()
-            .header(header::UPGRADE, header::HeaderValue::from_static("test"))
+            .insert_header((header::UPGRADE, header::HeaderValue::from_static("test")))
             .finish();
         assert_eq!(
             HandshakeError::NoWebsocketUpgrade,
-            verify_handshake(req.head()).err().unwrap()
+            verify_handshake(req.head()).unwrap_err(),
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
+            ))
             .finish();
         assert_eq!(
             HandshakeError::NoConnectionUpgrade,
-            verify_handshake(req.head()).err().unwrap()
+            verify_handshake(req.head()).unwrap_err(),
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
+            ))
             .finish();
         assert_eq!(
             HandshakeError::NoVersionHeader,
-            verify_handshake(req.head()).err().unwrap()
+            verify_handshake(req.head()).unwrap_err(),
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_VERSION,
                 header::HeaderValue::from_static("5"),
-            )
+            ))
             .finish();
         assert_eq!(
             HandshakeError::UnsupportedVersion,
-            verify_handshake(req.head()).err().unwrap()
+            verify_handshake(req.head()).unwrap_err(),
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_VERSION,
                 header::HeaderValue::from_static("13"),
-            )
+            ))
             .finish();
         assert_eq!(
             HandshakeError::BadWebsocketKey,
-            verify_handshake(req.head()).err().unwrap()
+            verify_handshake(req.head()).unwrap_err(),
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_VERSION,
                 header::HeaderValue::from_static("13"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_KEY,
                 header::HeaderValue::from_static("13"),
-            )
+            ))
             .finish();
         assert_eq!(
             StatusCode::SWITCHING_PROTOCOLS,
diff --git a/actix-http/src/ws/proto.rs b/actix-http/src/ws/proto.rs
index fc271a8f5..1e8bf7af3 100644
--- a/actix-http/src/ws/proto.rs
+++ b/actix-http/src/ws/proto.rs
@@ -1,28 +1,34 @@
 use std::convert::{From, Into};
 use std::fmt;
 
-use self::OpCode::*;
-/// Operation codes as part of rfc6455.
+/// Operation codes as part of RFC6455.
 #[derive(Debug, Eq, PartialEq, Clone, Copy)]
 pub enum OpCode {
     /// Indicates a continuation frame of a fragmented message.
     Continue,
+
     /// Indicates a text data frame.
     Text,
+
     /// Indicates a binary data frame.
     Binary,
+
     /// Indicates a close control frame.
     Close,
+
     /// Indicates a ping control frame.
     Ping,
+
     /// Indicates a pong control frame.
     Pong,
+
     /// Indicates an invalid opcode was received.
     Bad,
 }
 
 impl fmt::Display for OpCode {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        use self::OpCode::*;
         match *self {
             Continue => write!(f, "CONTINUE"),
             Text => write!(f, "TEXT"),
@@ -35,9 +41,10 @@ impl fmt::Display for OpCode {
     }
 }
 
-impl Into<u8> for OpCode {
-    fn into(self) -> u8 {
-        match self {
+impl From<OpCode> for u8 {
+    fn from(op: OpCode) -> u8 {
+        use self::OpCode::*;
+        match op {
             Continue => 0,
             Text => 1,
             Binary => 2,
@@ -54,6 +61,7 @@ impl Into<u8> for OpCode {
 
 impl From<u8> for OpCode {
     fn from(byte: u8) -> OpCode {
+        use self::OpCode::*;
         match byte {
             0 => Continue,
             1 => Text,
@@ -66,9 +74,7 @@ impl From<u8> for OpCode {
     }
 }
 
-use self::CloseCode::*;
-/// Status code used to indicate why an endpoint is closing the `WebSocket`
-/// connection.
+/// Status code used to indicate why an endpoint is closing the WebSocket connection.
 #[derive(Debug, Eq, PartialEq, Clone, Copy)]
 pub enum CloseCode {
     /// Indicates a normal closure, meaning that the purpose for
@@ -132,9 +138,10 @@ pub enum CloseCode {
     Other(u16),
 }
 
-impl Into<u16> for CloseCode {
-    fn into(self) -> u16 {
-        match self {
+impl From<CloseCode> for u16 {
+    fn from(code: CloseCode) -> u16 {
+        use self::CloseCode::*;
+        match code {
             Normal => 1000,
             Away => 1001,
             Protocol => 1002,
@@ -155,6 +162,7 @@ impl Into<u16> for CloseCode {
 
 impl From<u16> for CloseCode {
     fn from(code: u16) -> CloseCode {
+        use self::CloseCode::*;
         match code {
             1000 => Normal,
             1001 => Away,
@@ -179,6 +187,7 @@ impl From<u16> for CloseCode {
 pub struct CloseReason {
     /// Exit code
     pub code: CloseCode,
+
     /// Optional description of the exit code
     pub description: Option<String>,
 }
@@ -222,7 +231,7 @@ mod test {
     macro_rules! opcode_into {
         ($from:expr => $opcode:pat) => {
             match OpCode::from($from) {
-                e @ $opcode => (),
+                e @ $opcode => {}
                 e => unreachable!("{:?}", e),
             }
         };
@@ -232,7 +241,7 @@ mod test {
         ($from:expr => $opcode:pat) => {
             let res: u8 = $from.into();
             match res {
-                e @ $opcode => (),
+                e @ $opcode => {}
                 e => unreachable!("{:?}", e),
             }
         };
diff --git a/actix-http/tests/test_client.rs b/actix-http/tests/test_client.rs
index 07104decc..91b2412f4 100644
--- a/actix-http/tests/test_client.rs
+++ b/actix-http/tests/test_client.rs
@@ -1,9 +1,8 @@
-use actix_service::ServiceFactory;
-use bytes::Bytes;
-use futures_util::future::{self, ok};
-
 use actix_http::{http, HttpService, Request, Response};
 use actix_http_test::test_server;
+use actix_service::ServiceFactoryExt;
+use bytes::Bytes;
+use futures_util::future::{self, ok};
 
 const STR: &str = "Hello World Hello World Hello World Hello World Hello World \
                    Hello World Hello World Hello World Hello World Hello World \
@@ -39,7 +38,7 @@ async fn test_h1_v2() {
     let response = srv.get("/").send().await.unwrap();
     assert!(response.status().is_success());
 
-    let request = srv.get("/").header("x-test", "111").send();
+    let request = srv.get("/").insert_header(("x-test", "111")).send();
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
 
diff --git a/actix-http/tests/test_openssl.rs b/actix-http/tests/test_openssl.rs
index 795deacdc..f44968baa 100644
--- a/actix-http/tests/test_openssl.rs
+++ b/actix-http/tests/test_openssl.rs
@@ -1,19 +1,24 @@
 #![cfg(feature = "openssl")]
+
+extern crate tls_openssl as openssl;
+
 use std::io;
 
-use actix_http_test::test_server;
-use actix_service::{fn_service, ServiceFactory};
-
-use bytes::{Bytes, BytesMut};
-use futures_util::future::{err, ok, ready};
-use futures_util::stream::{once, Stream, StreamExt};
-use open_ssl::ssl::{AlpnError, SslAcceptor, SslFiletype, SslMethod};
-
 use actix_http::error::{ErrorBadRequest, PayloadError};
 use actix_http::http::header::{self, HeaderName, HeaderValue};
 use actix_http::http::{Method, StatusCode, Version};
-use actix_http::httpmessage::HttpMessage;
+use actix_http::HttpMessage;
 use actix_http::{body, Error, HttpService, Request, Response};
+use actix_http_test::test_server;
+use actix_service::{fn_service, ServiceFactoryExt};
+use bytes::{Bytes, BytesMut};
+use futures_util::future::{err, ok, ready};
+use futures_util::stream::{once, Stream, StreamExt};
+use openssl::{
+    pkey::PKey,
+    ssl::{SslAcceptor, SslMethod},
+    x509::X509,
+};
 
 async fn load_body<S>(stream: S) -> Result<BytesMut, PayloadError>
 where
@@ -33,29 +38,26 @@ where
     Ok(body)
 }
 
-fn ssl_acceptor() -> SslAcceptor {
-    // load ssl keys
+fn tls_config() -> SslAcceptor {
+    let cert = rcgen::generate_simple_self_signed(vec!["localhost".to_owned()]).unwrap();
+    let cert_file = cert.serialize_pem().unwrap();
+    let key_file = cert.serialize_private_key_pem();
+    let cert = X509::from_pem(cert_file.as_bytes()).unwrap();
+    let key = PKey::private_key_from_pem(key_file.as_bytes()).unwrap();
+
     let mut builder = SslAcceptor::mozilla_intermediate(SslMethod::tls()).unwrap();
-    builder
-        .set_private_key_file("../tests/key.pem", SslFiletype::PEM)
-        .unwrap();
-    builder
-        .set_certificate_chain_file("../tests/cert.pem")
-        .unwrap();
+    builder.set_certificate(&cert).unwrap();
+    builder.set_private_key(&key).unwrap();
+
     builder.set_alpn_select_callback(|_, protos| {
         const H2: &[u8] = b"\x02h2";
-        const H11: &[u8] = b"\x08http/1.1";
         if protos.windows(3).any(|window| window == H2) {
             Ok(b"h2")
-        } else if protos.windows(9).any(|window| window == H11) {
-            Ok(b"http/1.1")
         } else {
-            Err(AlpnError::NOACK)
+            Err(openssl::ssl::AlpnError::NOACK)
         }
     });
-    builder
-        .set_alpn_protos(b"\x08http/1.1\x02h2")
-        .expect("Can not contrust SslAcceptor");
+    builder.set_alpn_protos(b"\x02h2").unwrap();
 
     builder.build()
 }
@@ -65,7 +67,7 @@ async fn test_h2() -> io::Result<()> {
     let srv = test_server(move || {
         HttpService::build()
             .h2(|_| ok::<_, Error>(Response::Ok().finish()))
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -84,7 +86,7 @@ async fn test_h2_1() -> io::Result<()> {
                 assert_eq!(req.version(), Version::HTTP_2);
                 ok::<_, Error>(Response::Ok().finish())
             })
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -103,7 +105,7 @@ async fn test_h2_body() -> io::Result<()> {
                 let body = load_body(req.take_payload()).await?;
                 Ok::<_, Error>(Response::Ok().body(body))
             })
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -132,7 +134,7 @@ async fn test_h2_content_length() {
                 ];
                 ok::<_, ()>(Response::new(statuses[indx]))
             })
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -175,8 +177,8 @@ async fn test_h2_headers() {
         HttpService::build().h2(move |_| {
             let mut builder = Response::Ok();
             for idx in 0..90 {
-                builder.header(
-                    format!("X-TEST-{}", idx).as_str(),
+                builder.insert_header(
+                    (format!("X-TEST-{}", idx).as_str(),
                     "TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
@@ -190,11 +192,11 @@ async fn test_h2_headers() {
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST ",
-                );
+                ));
             }
             ok::<_, ()>(builder.body(data.clone()))
         })
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
                     .map_err(|_| ())
     }).await;
 
@@ -233,7 +235,7 @@ async fn test_h2_body2() {
     let mut srv = test_server(move || {
         HttpService::build()
             .h2(|_| ok::<_, ()>(Response::Ok().body(STR)))
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -251,7 +253,7 @@ async fn test_h2_head_empty() {
     let mut srv = test_server(move || {
         HttpService::build()
             .finish(|_| ok::<_, ()>(Response::Ok().body(STR)))
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -275,7 +277,7 @@ async fn test_h2_head_binary() {
     let mut srv = test_server(move || {
         HttpService::build()
             .h2(|_| ok::<_, ()>(Response::Ok().body(STR)))
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -298,7 +300,7 @@ async fn test_h2_head_binary2() {
     let srv = test_server(move || {
         HttpService::build()
             .h2(|_| ok::<_, ()>(Response::Ok().body(STR)))
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -322,7 +324,7 @@ async fn test_h2_body_length() {
                     Response::Ok().body(body::SizedStream::new(STR.len() as u64, body)),
                 )
             })
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -343,11 +345,11 @@ async fn test_h2_body_chunked_explicit() {
                 let body = once(ok::<_, Error>(Bytes::from_static(STR.as_ref())));
                 ok::<_, ()>(
                     Response::Ok()
-                        .header(header::TRANSFER_ENCODING, "chunked")
+                        .insert_header((header::TRANSFER_ENCODING, "chunked"))
                         .streaming(body),
                 )
             })
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -371,11 +373,11 @@ async fn test_h2_response_http_error_handling() {
                 let broken_header = Bytes::from_static(b"\0\0\0");
                 ok::<_, ()>(
                     Response::Ok()
-                        .header(header::CONTENT_TYPE, broken_header)
+                        .insert_header((header::CONTENT_TYPE, broken_header))
                         .body(STR),
                 )
             }))
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -393,7 +395,7 @@ async fn test_h2_service_error() {
     let mut srv = test_server(move || {
         HttpService::build()
             .h2(|_| err::<Response, Error>(ErrorBadRequest("error")))
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -410,12 +412,14 @@ async fn test_h2_service_error() {
 async fn test_h2_on_connect() {
     let srv = test_server(move || {
         HttpService::build()
-            .on_connect(|_| 10usize)
+            .on_connect_ext(|_, data| {
+                data.insert(20isize);
+            })
             .h2(|req: Request| {
-                assert!(req.extensions().contains::<usize>());
+                assert!(req.extensions().contains::<isize>());
                 ok::<_, ()>(Response::Ok().finish())
             })
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
diff --git a/actix-http/tests/test_rustls.rs b/actix-http/tests/test_rustls.rs
index beae359d9..a36400910 100644
--- a/actix-http/tests/test_rustls.rs
+++ b/actix-http/tests/test_rustls.rs
@@ -1,4 +1,7 @@
 #![cfg(feature = "rustls")]
+
+extern crate tls_rustls as rustls;
+
 use actix_http::error::PayloadError;
 use actix_http::http::header::{self, HeaderName, HeaderValue};
 use actix_http::http::{Method, StatusCode, Version};
@@ -9,7 +12,7 @@ use actix_service::{fn_factory_with_config, fn_service};
 use bytes::{Bytes, BytesMut};
 use futures_util::future::{self, err, ok};
 use futures_util::stream::{once, Stream, StreamExt};
-use rust_tls::{
+use rustls::{
     internal::pemfile::{certs, pkcs8_private_keys},
     NoClientAuth, ServerConfig as RustlsServerConfig,
 };
@@ -28,14 +31,19 @@ where
     Ok(body)
 }
 
-fn ssl_acceptor() -> RustlsServerConfig {
-    // load ssl keys
+fn tls_config() -> RustlsServerConfig {
+    let cert = rcgen::generate_simple_self_signed(vec!["localhost".to_owned()]).unwrap();
+    let cert_file = cert.serialize_pem().unwrap();
+    let key_file = cert.serialize_private_key_pem();
+
     let mut config = RustlsServerConfig::new(NoClientAuth::new());
-    let cert_file = &mut BufReader::new(File::open("../tests/cert.pem").unwrap());
-    let key_file = &mut BufReader::new(File::open("../tests/key.pem").unwrap());
+    let cert_file = &mut BufReader::new(cert_file.as_bytes());
+    let key_file = &mut BufReader::new(key_file.as_bytes());
+
     let cert_chain = certs(cert_file).unwrap();
     let mut keys = pkcs8_private_keys(key_file).unwrap();
     config.set_single_cert(cert_chain, keys.remove(0)).unwrap();
+
     config
 }
 
@@ -44,7 +52,7 @@ async fn test_h1() -> io::Result<()> {
     let srv = test_server(move || {
         HttpService::build()
             .h1(|_| future::ok::<_, Error>(Response::Ok().finish()))
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -58,7 +66,7 @@ async fn test_h2() -> io::Result<()> {
     let srv = test_server(move || {
         HttpService::build()
             .h2(|_| future::ok::<_, Error>(Response::Ok().finish()))
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -76,7 +84,7 @@ async fn test_h1_1() -> io::Result<()> {
                 assert_eq!(req.version(), Version::HTTP_11);
                 future::ok::<_, Error>(Response::Ok().finish())
             })
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -94,7 +102,7 @@ async fn test_h2_1() -> io::Result<()> {
                 assert_eq!(req.version(), Version::HTTP_2);
                 future::ok::<_, Error>(Response::Ok().finish())
             })
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -112,7 +120,7 @@ async fn test_h2_body1() -> io::Result<()> {
                 let body = load_body(req.take_payload()).await?;
                 Ok::<_, Error>(Response::Ok().body(body))
             })
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -140,7 +148,7 @@ async fn test_h2_content_length() {
                 ];
                 future::ok::<_, ()>(Response::new(statuses[indx]))
             })
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -181,7 +189,7 @@ async fn test_h2_headers() {
         HttpService::build().h2(move |_| {
             let mut config = Response::Ok();
             for idx in 0..90 {
-                config.header(
+                config.insert_header((
                     format!("X-TEST-{}", idx).as_str(),
                     "TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
@@ -196,11 +204,11 @@ async fn test_h2_headers() {
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST ",
-                );
+                ));
             }
             future::ok::<_, ()>(config.body(data.clone()))
         })
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     }).await;
 
     let response = srv.sget("/").send().await.unwrap();
@@ -238,7 +246,7 @@ async fn test_h2_body2() {
     let mut srv = test_server(move || {
         HttpService::build()
             .h2(|_| future::ok::<_, ()>(Response::Ok().body(STR)))
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -255,7 +263,7 @@ async fn test_h2_head_empty() {
     let mut srv = test_server(move || {
         HttpService::build()
             .finish(|_| ok::<_, ()>(Response::Ok().body(STR)))
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -281,7 +289,7 @@ async fn test_h2_head_binary() {
     let mut srv = test_server(move || {
         HttpService::build()
             .h2(|_| ok::<_, ()>(Response::Ok().body(STR)))
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -306,7 +314,7 @@ async fn test_h2_head_binary2() {
     let srv = test_server(move || {
         HttpService::build()
             .h2(|_| ok::<_, ()>(Response::Ok().body(STR)))
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -332,7 +340,7 @@ async fn test_h2_body_length() {
                     Response::Ok().body(body::SizedStream::new(STR.len() as u64, body)),
                 )
             })
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -352,11 +360,11 @@ async fn test_h2_body_chunked_explicit() {
                 let body = once(ok::<_, Error>(Bytes::from_static(STR.as_ref())));
                 ok::<_, ()>(
                     Response::Ok()
-                        .header(header::TRANSFER_ENCODING, "chunked")
+                        .insert_header((header::TRANSFER_ENCODING, "chunked"))
                         .streaming(body),
                 )
             })
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -380,12 +388,12 @@ async fn test_h2_response_http_error_handling() {
                     let broken_header = Bytes::from_static(b"\0\0\0");
                     ok::<_, ()>(
                         Response::Ok()
-                            .header(http::header::CONTENT_TYPE, broken_header)
+                            .insert_header((http::header::CONTENT_TYPE, broken_header))
                             .body(STR),
                     )
                 }))
             }))
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -402,7 +410,7 @@ async fn test_h2_service_error() {
     let mut srv = test_server(move || {
         HttpService::build()
             .h2(|_| err::<Response, Error>(error::ErrorBadRequest("error")))
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
@@ -419,7 +427,7 @@ async fn test_h1_service_error() {
     let mut srv = test_server(move || {
         HttpService::build()
             .h1(|_| err::<Response, Error>(error::ErrorBadRequest("error")))
-            .rustls(ssl_acceptor())
+            .rustls(tls_config())
     })
     .await;
 
diff --git a/actix-http/tests/test_server.rs b/actix-http/tests/test_server.rs
index 0375b6f66..910fa81f2 100644
--- a/actix-http/tests/test_server.rs
+++ b/actix-http/tests/test_server.rs
@@ -3,14 +3,14 @@ use std::time::Duration;
 use std::{net, thread};
 
 use actix_http_test::test_server;
-use actix_rt::time::delay_for;
+use actix_rt::time::sleep;
 use actix_service::fn_service;
 use bytes::Bytes;
 use futures_util::future::{self, err, ok, ready, FutureExt};
 use futures_util::stream::{once, StreamExt};
 use regex::Regex;
 
-use actix_http::httpmessage::HttpMessage;
+use actix_http::HttpMessage;
 use actix_http::{
     body, error, http, http::header, Error, HttpService, KeepAlive, Request, Response,
 };
@@ -88,7 +88,7 @@ async fn test_expect_continue_h1() {
     let srv = test_server(|| {
         HttpService::build()
             .expect(fn_service(|req: Request| {
-                delay_for(Duration::from_millis(20)).then(move |_| {
+                sleep(Duration::from_millis(20)).then(move |_| {
                     if req.head().uri.query() == Some("yes=") {
                         ok(req)
                     } else {
@@ -392,7 +392,7 @@ async fn test_h1_headers() {
         HttpService::build().h1(move |_| {
             let mut builder = Response::Ok();
             for idx in 0..90 {
-                builder.header(
+                builder.insert_header((
                     format!("X-TEST-{}", idx).as_str(),
                     "TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
@@ -407,7 +407,7 @@ async fn test_h1_headers() {
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                         TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST ",
-                );
+                ));
             }
             future::ok::<_, ()>(builder.body(data.clone()))
         }).tcp()
@@ -561,7 +561,7 @@ async fn test_h1_body_chunked_explicit() {
                 let body = once(ok::<_, Error>(Bytes::from_static(STR.as_ref())));
                 ok::<_, ()>(
                     Response::Ok()
-                        .header(header::TRANSFER_ENCODING, "chunked")
+                        .insert_header((header::TRANSFER_ENCODING, "chunked"))
                         .streaming(body),
                 )
             })
@@ -625,7 +625,7 @@ async fn test_h1_response_http_error_handling() {
                 let broken_header = Bytes::from_static(b"\0\0\0");
                 ok::<_, ()>(
                     Response::Ok()
-                        .header(http::header::CONTENT_TYPE, broken_header)
+                        .insert_header((http::header::CONTENT_TYPE, broken_header))
                         .body(STR),
                 )
             }))
@@ -662,9 +662,11 @@ async fn test_h1_service_error() {
 async fn test_h1_on_connect() {
     let srv = test_server(|| {
         HttpService::build()
-            .on_connect(|_| 10usize)
+            .on_connect_ext(|_, data| {
+                data.insert(20isize);
+            })
             .h1(|req: Request| {
-                assert!(req.extensions().contains::<usize>());
+                assert!(req.extensions().contains::<isize>());
                 future::ok::<_, ()>(Response::Ok().finish())
             })
             .tcp()
diff --git a/actix-http/tests/test_ws.rs b/actix-http/tests/test_ws.rs
index 5d86605f4..7ed9b0df1 100644
--- a/actix-http/tests/test_ws.rs
+++ b/actix-http/tests/test_ws.rs
@@ -21,7 +21,7 @@ impl<T> WsService<T> {
         WsService(Arc::new(Mutex::new((PhantomData, Cell::new(false)))))
     }
 
-    fn set_polled(&mut self) {
+    fn set_polled(&self) {
         *self.0.lock().unwrap().1.get_mut() = true;
     }
 
@@ -36,21 +36,20 @@ impl<T> Clone for WsService<T> {
     }
 }
 
-impl<T> Service for WsService<T>
+impl<T> Service<(Request, Framed<T, h1::Codec>)> for WsService<T>
 where
     T: AsyncRead + AsyncWrite + Unpin + 'static,
 {
-    type Request = (Request, Framed<T, h1::Codec>);
     type Response = ();
     type Error = Error;
     type Future = Pin<Box<dyn Future<Output = Result<(), Error>>>>;
 
-    fn poll_ready(&mut self, _ctx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    fn poll_ready(&self, _ctx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         self.set_polled();
         Poll::Ready(Ok(()))
     }
 
-    fn call(&mut self, (req, mut framed): Self::Request) -> Self::Future {
+    fn call(&self, (req, mut framed): (Request, Framed<T, h1::Codec>)) -> Self::Future {
         let fut = async move {
             let res = ws::handshake(req.head()).unwrap().message_body(());
 
@@ -72,7 +71,7 @@ async fn service(msg: ws::Frame) -> Result<ws::Message, Error> {
     let msg = match msg {
         ws::Frame::Ping(msg) => ws::Message::Pong(msg),
         ws::Frame::Text(text) => {
-            ws::Message::Text(String::from_utf8_lossy(&text).to_string())
+            ws::Message::Text(String::from_utf8_lossy(&text).into_owned().into())
         }
         ws::Frame::Binary(bin) => ws::Message::Binary(bin),
         ws::Frame::Continuation(item) => ws::Message::Continuation(item),
@@ -99,10 +98,7 @@ async fn test_simple() {
 
     // client service
     let mut framed = srv.ws().await.unwrap();
-    framed
-        .send(ws::Message::Text("text".to_string()))
-        .await
-        .unwrap();
+    framed.send(ws::Message::Text("text".into())).await.unwrap();
     let (item, mut framed) = framed.into_future().await;
     assert_eq!(
         item.unwrap().unwrap(),
diff --git a/actix-multipart/CHANGES.md b/actix-multipart/CHANGES.md
index 446ca5ad2..2142ebf4b 100644
--- a/actix-multipart/CHANGES.md
+++ b/actix-multipart/CHANGES.md
@@ -1,14 +1,25 @@
 # Changes
 
-## Unreleased - 2020-xx-xx
-* Fix multipart consuming payload before header checks #1513
+## Unreleased - 2021-xx-xx
 
 
-## 3.0.0 - 2020-09-11
-* No significant changes from `3.0.0-beta.2`.
+## 0.4.0-beta.2 - 2021-02-10
+* No notable changes.
 
 
-## 3.0.0-beta.2 - 2020-09-10
+## 0.4.0-beta.1 - 2021-01-07
+* Fix multipart consuming payload before header checks. [#1513]
+* Update `bytes` to `1.0`. [#1813]
+
+[#1813]: https://github.com/actix/actix-web/pull/1813
+[#1513]: https://github.com/actix/actix-web/pull/1513
+
+
+## 0.3.0 - 2020-09-11
+* No significant changes from `0.3.0-beta.2`.
+
+
+## 0.3.0-beta.2 - 2020-09-10
 * Update `actix-*` dependencies to latest versions.
 
 
diff --git a/actix-multipart/Cargo.toml b/actix-multipart/Cargo.toml
index e2e9dbf14..67b2698bd 100644
--- a/actix-multipart/Cargo.toml
+++ b/actix-multipart/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "actix-multipart"
-version = "0.3.0"
+version = "0.4.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
-description = "Multipart support for actix web framework."
+description = "Multipart form support for Actix Web"
 readme = "README.md"
 keywords = ["http", "web", "framework", "async", "futures"]
 homepage = "https://actix.rs"
@@ -16,17 +16,17 @@ name = "actix_multipart"
 path = "src/lib.rs"
 
 [dependencies]
-actix-web = { version = "3.0.0", default-features = false }
-actix-service = "1.0.6"
-actix-utils = "2.0.0"
-bytes = "0.5.3"
-derive_more = "0.99.2"
+actix-web = { version = "4.0.0-beta.3", default-features = false }
+actix-utils = "3.0.0-beta.2"
+
+bytes = "1"
+derive_more = "0.99.5"
 httparse = "1.3"
-futures-util = { version = "0.3.5", default-features = false }
+futures-util = { version = "0.3.7", default-features = false }
 log = "0.4"
 mime = "0.3"
 twoway = "0.2"
 
 [dev-dependencies]
-actix-rt = "1.0.0"
-actix-http = "2.0.0"
+actix-rt = "2"
+actix-http = "3.0.0-beta.3"
diff --git a/actix-multipart/README.md b/actix-multipart/README.md
index edb2e0020..defcf7828 100644
--- a/actix-multipart/README.md
+++ b/actix-multipart/README.md
@@ -1,8 +1,18 @@
-# Multipart support for actix web framework [![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web) [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) [![crates.io](https://meritbadge.herokuapp.com/actix-multipart)](https://crates.io/crates/actix-multipart) [![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+# actix-multipart
 
-## Documentation & community resources
+> Multipart form support for Actix Web.
 
-* [API Documentation](https://docs.rs/actix-multipart/)
-* [Chat on gitter](https://gitter.im/actix/actix)
-* Cargo package: [actix-multipart](https://crates.io/crates/actix-multipart)
-* Minimum supported Rust version: 1.40 or later
+[![crates.io](https://img.shields.io/crates/v/actix-multipart?label=latest)](https://crates.io/crates/actix-multipart)
+[![Documentation](https://docs.rs/actix-multipart/badge.svg?version=0.4.0-beta.2)](https://docs.rs/actix-multipart/0.4.0-beta.2)
+[![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
+![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/actix-multipart.svg)
+<br />
+[![dependency status](https://deps.rs/crate/actix-multipart/0.4.0-beta.2/status.svg)](https://deps.rs/crate/actix-multipart/0.4.0-beta.2)
+[![Download](https://img.shields.io/crates/d/actix-multipart.svg)](https://crates.io/crates/actix-multipart)
+[![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
+## Documentation & Resources
+
+- [API Documentation](https://docs.rs/actix-multipart)
+- [Chat on Gitter](https://gitter.im/actix/actix-web)
+- Minimum Supported Rust Version (MSRV): 1.46.0
diff --git a/actix-multipart/src/lib.rs b/actix-multipart/src/lib.rs
index 46dd0ee9b..38a24e28f 100644
--- a/actix-multipart/src/lib.rs
+++ b/actix-multipart/src/lib.rs
@@ -1,4 +1,4 @@
-//! Multipart form support for Actix web.
+//! Multipart form support for Actix Web.
 
 #![deny(rust_2018_idioms)]
 #![allow(clippy::borrow_interior_mutable_const)]
diff --git a/actix-multipart/src/server.rs b/actix-multipart/src/server.rs
index b9ebf97cc..8cd1c8e0c 100644
--- a/actix-multipart/src/server.rs
+++ b/actix-multipart/src/server.rs
@@ -13,9 +13,7 @@ use futures_util::stream::{LocalBoxStream, Stream, StreamExt};
 
 use actix_utils::task::LocalWaker;
 use actix_web::error::{ParseError, PayloadError};
-use actix_web::http::header::{
-    self, ContentDisposition, HeaderMap, HeaderName, HeaderValue,
-};
+use actix_web::http::header::{self, ContentDisposition, HeaderMap, HeaderName, HeaderValue};
 
 use crate::error::MultipartError;
 
@@ -120,10 +118,7 @@ impl Multipart {
 impl Stream for Multipart {
     type Item = Result<Field, MultipartError>;
 
-    fn poll_next(
-        mut self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         if let Some(err) = self.error.take() {
             Poll::Ready(Some(Err(err)))
         } else if self.safety.current() {
@@ -142,9 +137,7 @@ impl Stream for Multipart {
 }
 
 impl InnerMultipart {
-    fn read_headers(
-        payload: &mut PayloadBuffer,
-    ) -> Result<Option<HeaderMap>, MultipartError> {
+    fn read_headers(payload: &mut PayloadBuffer) -> Result<Option<HeaderMap>, MultipartError> {
         match payload.read_until(b"\r\n\r\n")? {
             None => {
                 if payload.eof {
@@ -226,8 +219,7 @@ impl InnerMultipart {
                     if chunk.len() < boundary.len() {
                         continue;
                     }
-                    if &chunk[..2] == b"--"
-                        && &chunk[2..chunk.len() - 2] == boundary.as_bytes()
+                    if &chunk[..2] == b"--" && &chunk[2..chunk.len() - 2] == boundary.as_bytes()
                     {
                         break;
                     } else {
@@ -273,9 +265,7 @@ impl InnerMultipart {
                             match field.borrow_mut().poll(safety) {
                                 Poll::Pending => return Poll::Pending,
                                 Poll::Ready(Some(Ok(_))) => continue,
-                                Poll::Ready(Some(Err(e))) => {
-                                    return Poll::Ready(Some(Err(e)))
-                                }
+                                Poll::Ready(Some(Err(e))) => return Poll::Ready(Some(Err(e))),
                                 Poll::Ready(None) => true,
                             }
                         }
@@ -311,10 +301,7 @@ impl InnerMultipart {
                     }
                     // read boundary
                     InnerState::Boundary => {
-                        match InnerMultipart::read_boundary(
-                            &mut *payload,
-                            &self.boundary,
-                        )? {
+                        match InnerMultipart::read_boundary(&mut *payload, &self.boundary)? {
                             None => return Poll::Pending,
                             Some(eof) => {
                                 if eof {
@@ -326,7 +313,7 @@ impl InnerMultipart {
                             }
                         }
                     }
-                    _ => (),
+                    _ => {}
                 }
 
                 // read field headers for next field
@@ -418,8 +405,7 @@ impl Field {
     pub fn content_disposition(&self) -> Option<ContentDisposition> {
         // RFC 7578: 'Each part MUST contain a Content-Disposition header field
         // where the disposition type is "form-data".'
-        if let Some(content_disposition) = self.headers.get(&header::CONTENT_DISPOSITION)
-        {
+        if let Some(content_disposition) = self.headers.get(&header::CONTENT_DISPOSITION) {
             ContentDisposition::from_raw(content_disposition).ok()
         } else {
             None
@@ -430,15 +416,10 @@ impl Field {
 impl Stream for Field {
     type Item = Result<Bytes, MultipartError>;
 
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         if self.safety.current() {
             let mut inner = self.inner.borrow_mut();
-            if let Some(mut payload) =
-                inner.payload.as_ref().unwrap().get_mut(&self.safety)
-            {
+            if let Some(mut payload) = inner.payload.as_ref().unwrap().get_mut(&self.safety) {
                 payload.poll_stream(cx)?;
             }
             inner.poll(&self.safety)
@@ -607,8 +588,7 @@ impl InnerField {
             return Poll::Ready(None);
         }
 
-        let result = if let Some(mut payload) = self.payload.as_ref().unwrap().get_mut(s)
-        {
+        let result = if let Some(mut payload) = self.payload.as_ref().unwrap().get_mut(s) {
             if !self.eof {
                 let res = if let Some(ref mut len) = self.length {
                     InnerField::read_len(&mut *payload, len)
@@ -628,7 +608,9 @@ impl InnerField {
                 Ok(None) => Poll::Pending,
                 Ok(Some(line)) => {
                     if line.as_ref() != b"\r\n" {
-                        log::warn!("multipart field did not read all the data or it is malformed");
+                        log::warn!(
+                            "multipart field did not read all the data or it is malformed"
+                        );
                     }
                     Poll::Ready(None)
                 }
@@ -725,9 +707,7 @@ impl Drop for Safety {
         if Rc::strong_count(&self.payload) != self.level {
             self.clean.set(true);
         }
-        if let Some(task) = self.task.take() {
-            task.wake()
-        }
+        self.task.wake();
     }
 }
 
@@ -806,9 +786,7 @@ impl PayloadBuffer {
     /// Read bytes until new line delimiter or eof
     pub fn readline_or_eof(&mut self) -> Result<Option<Bytes>, MultipartError> {
         match self.readline() {
-            Err(MultipartError::Incomplete) if self.eof => {
-                Ok(Some(self.buf.split().freeze()))
-            }
+            Err(MultipartError::Incomplete) if self.eof => Ok(Some(self.buf.split().freeze())),
             line => line,
         }
     }
@@ -837,7 +815,7 @@ mod tests {
     async fn test_boundary() {
         let headers = HeaderMap::new();
         match Multipart::boundary(&headers) {
-            Err(MultipartError::NoContentType) => (),
+            Err(MultipartError::NoContentType) => {}
             _ => unreachable!("should not happen"),
         }
 
@@ -848,7 +826,7 @@ mod tests {
         );
 
         match Multipart::boundary(&headers) {
-            Err(MultipartError::ParseContentType) => (),
+            Err(MultipartError::ParseContentType) => {}
             _ => unreachable!("should not happen"),
         }
 
@@ -858,7 +836,7 @@ mod tests {
             header::HeaderValue::from_static("multipart/mixed"),
         );
         match Multipart::boundary(&headers) {
-            Err(MultipartError::Boundary) => (),
+            Err(MultipartError::Boundary) => {}
             _ => unreachable!("should not happen"),
         }
 
@@ -904,10 +882,7 @@ mod tests {
     impl Stream for SlowStream {
         type Item = Result<Bytes, PayloadError>;
 
-        fn poll_next(
-            self: Pin<&mut Self>,
-            cx: &mut Context<'_>,
-        ) -> Poll<Option<Self::Item>> {
+        fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
             let this = self.get_mut();
             if !this.ready {
                 this.ready = true;
@@ -958,17 +933,17 @@ mod tests {
         let mut multipart = Multipart::new(&headers, payload);
 
         match multipart.next().await.unwrap() {
-            Ok(_) => (),
+            Ok(_) => {}
             _ => unreachable!(),
         }
 
         match multipart.next().await.unwrap() {
-            Ok(_) => (),
+            Ok(_) => {}
             _ => unreachable!(),
         }
 
         match multipart.next().await {
-            None => (),
+            None => {}
             _ => unreachable!(),
         }
     }
@@ -995,7 +970,7 @@ mod tests {
                     _ => unreachable!(),
                 }
                 match field.next().await {
-                    None => (),
+                    None => {}
                     _ => unreachable!(),
                 }
             }
@@ -1012,7 +987,7 @@ mod tests {
                     _ => unreachable!(),
                 }
                 match field.next().await {
-                    None => (),
+                    None => {}
                     _ => unreachable!(),
                 }
             }
@@ -1020,7 +995,7 @@ mod tests {
         }
 
         match multipart.next().await {
-            None => (),
+            None => {}
             _ => unreachable!(),
         }
     }
@@ -1068,7 +1043,7 @@ mod tests {
         }
 
         match multipart.next().await {
-            None => (),
+            None => {}
             _ => unreachable!(),
         }
     }
diff --git a/actix-web-actors/CHANGES.md b/actix-web-actors/CHANGES.md
index 4b9381a33..acd9ceada 100644
--- a/actix-web-actors/CHANGES.md
+++ b/actix-web-actors/CHANGES.md
@@ -1,6 +1,19 @@
 # Changes
 
-## Unreleased - 2020-xx-xx
+## Unreleased - 2021-xx-xx
+
+
+## 4.0.0-beta.2 - 2021-02-10
+* No notable changes.
+
+
+## 4.0.0-beta.1 - 2021-01-07
+* Update `pin-project` to `1.0`.
+* Update `bytes` to `1.0`. [#1813]
+* `WebsocketContext::text` now takes an `Into<bytestring::ByteString>`. [#1864]
+
+[#1813]: https://github.com/actix/actix-web/pull/1813
+[#1864]: https://github.com/actix/actix-web/pull/1864
 
 
 ## 3.0.0 - 2020-09-11
diff --git a/actix-web-actors/Cargo.toml b/actix-web-actors/Cargo.toml
index 2f3c63022..698ff9420 100644
--- a/actix-web-actors/Cargo.toml
+++ b/actix-web-actors/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "actix-web-actors"
-version = "3.0.0"
+version = "4.0.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
-description = "Actix actors support for actix web framework."
+description = "Actix actors support for Actix Web"
 readme = "README.md"
 keywords = ["actix", "http", "web", "framework", "async"]
 homepage = "https://actix.rs"
@@ -16,16 +16,18 @@ name = "actix_web_actors"
 path = "src/lib.rs"
 
 [dependencies]
-actix = "0.10.0"
-actix-web = { version = "3.0.0", default-features = false }
-actix-http = "2.0.0"
-actix-codec = "0.3.0"
-bytes = "0.5.2"
-futures-channel = { version = "0.3.5", default-features = false }
-futures-core = { version = "0.3.5", default-features = false }
-pin-project = "0.4.17"
+actix = { version = "0.11.0-beta.2", default-features = false }
+actix-codec = "0.4.0-beta.1"
+actix-http = "3.0.0-beta.3"
+actix-web = { version = "4.0.0-beta.3", default-features = false }
+
+bytes = "1"
+bytestring = "1"
+futures-core = { version = "0.3.7", default-features = false }
+pin-project = "1.0.0"
+tokio = { version = "1", features = ["sync"] }
 
 [dev-dependencies]
-actix-rt = "1.1.1"
-env_logger = "0.7"
-futures-util = { version = "0.3.5", default-features = false }
+actix-rt = "2"
+env_logger = "0.8"
+futures-util = { version = "0.3.7", default-features = false }
diff --git a/actix-web-actors/README.md b/actix-web-actors/README.md
index fb8c3a621..c9b588153 100644
--- a/actix-web-actors/README.md
+++ b/actix-web-actors/README.md
@@ -1,8 +1,18 @@
-Actix actors support for actix web framework [![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web) [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) [![crates.io](https://meritbadge.herokuapp.com/actix-web-actors)](https://crates.io/crates/actix-web-actors) [![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+# actix-web-actors
 
-## Documentation & community resources
+> Actix actors support for Actix Web.
 
-* [API Documentation](https://docs.rs/actix-web-actors/)
-* [Chat on gitter](https://gitter.im/actix/actix)
-* Cargo package: [actix-web-actors](https://crates.io/crates/actix-web-actors)
-* Minimum supported Rust version: 1.40 or later
+[![crates.io](https://img.shields.io/crates/v/actix-web-actors?label=latest)](https://crates.io/crates/actix-web-actors)
+[![Documentation](https://docs.rs/actix-web-actors/badge.svg?version=0.5.0)](https://docs.rs/actix-web-actors/0.5.0)
+[![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
+![License](https://img.shields.io/crates/l/actix-web-actors.svg)
+<br />
+[![dependency status](https://deps.rs/crate/actix-web-actors/0.5.0/status.svg)](https://deps.rs/crate/actix-web-actors/0.5.0)
+[![Download](https://img.shields.io/crates/d/actix-web-actors.svg)](https://crates.io/crates/actix-web-actors)
+[![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
+## Documentation & Resources
+
+- [API Documentation](https://docs.rs/actix-web-actors)
+- [Chat on Gitter](https://gitter.im/actix/actix-web)
+- Minimum supported Rust version: 1.46 or later
diff --git a/actix-web-actors/src/context.rs b/actix-web-actors/src/context.rs
index 0839a4288..bd6635cba 100644
--- a/actix-web-actors/src/context.rs
+++ b/actix-web-actors/src/context.rs
@@ -3,19 +3,17 @@ use std::future::Future;
 use std::pin::Pin;
 use std::task::{Context, Poll};
 
-use actix::dev::{
-    AsyncContextParts, ContextFut, ContextParts, Envelope, Mailbox, ToEnvelope,
-};
+use actix::dev::{AsyncContextParts, ContextFut, ContextParts, Envelope, Mailbox, ToEnvelope};
 use actix::fut::ActorFuture;
 use actix::{
     Actor, ActorContext, ActorState, Addr, AsyncContext, Handler, Message, SpawnHandle,
 };
 use actix_web::error::Error;
 use bytes::Bytes;
-use futures_channel::oneshot::Sender;
 use futures_core::Stream;
+use tokio::sync::oneshot::Sender;
 
-/// Execution context for http actors
+/// Execution context for HTTP actors
 pub struct HttpContext<A>
 where
     A: Actor<Context = HttpContext<A>>,
@@ -165,10 +163,7 @@ where
 {
     type Item = Result<Bytes, Error>;
 
-    fn poll_next(
-        mut self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         if self.fut.alive() {
             let _ = Pin::new(&mut self.fut).poll(cx);
         }
@@ -233,14 +228,14 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_default_resource() {
-        let mut srv =
+        let srv =
             init_service(App::new().service(web::resource("/test").to(|| {
                 HttpResponse::Ok().streaming(HttpContext::create(MyActor { count: 0 }))
             })))
             .await;
 
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
         let body = read_body(resp).await;
diff --git a/actix-web-actors/src/lib.rs b/actix-web-actors/src/lib.rs
index 0421f05fb..7a4823d91 100644
--- a/actix-web-actors/src/lib.rs
+++ b/actix-web-actors/src/lib.rs
@@ -1,4 +1,4 @@
-//! Actix actors integration for Actix web framework
+//! Actix actors support for Actix Web.
 
 #![deny(rust_2018_idioms)]
 #![allow(clippy::borrow_interior_mutable_const)]
diff --git a/actix-web-actors/src/ws.rs b/actix-web-actors/src/ws.rs
index 3f5972532..1ab4cfce5 100644
--- a/actix-web-actors/src/ws.rs
+++ b/actix-web-actors/src/ws.rs
@@ -1,18 +1,18 @@
-//! Websocket integration
-use std::collections::VecDeque;
+//! Websocket integration.
+
 use std::future::Future;
 use std::io;
 use std::pin::Pin;
 use std::task::{Context, Poll};
+use std::{collections::VecDeque, convert::TryFrom};
 
 use actix::dev::{
-    AsyncContextParts, ContextFut, ContextParts, Envelope, Mailbox, StreamHandler,
-    ToEnvelope,
+    AsyncContextParts, ContextFut, ContextParts, Envelope, Mailbox, StreamHandler, ToEnvelope,
 };
 use actix::fut::ActorFuture;
 use actix::{
-    Actor, ActorContext, ActorState, Addr, AsyncContext, Handler,
-    Message as ActixMessage, SpawnHandle,
+    Actor, ActorContext, ActorState, Addr, AsyncContext, Handler, Message as ActixMessage,
+    SpawnHandle,
 };
 use actix_codec::{Decoder, Encoder};
 use actix_http::ws::{hash_key, Codec};
@@ -24,21 +24,21 @@ use actix_web::error::{Error, PayloadError};
 use actix_web::http::{header, Method, StatusCode};
 use actix_web::{HttpRequest, HttpResponse};
 use bytes::{Bytes, BytesMut};
-use futures_channel::oneshot::Sender;
+use bytestring::ByteString;
 use futures_core::Stream;
+use tokio::sync::oneshot::Sender;
 
-/// Do websocket handshake and start ws actor.
+/// Perform WebSocket handshake and start actor.
 pub fn start<A, T>(actor: A, req: &HttpRequest, stream: T) -> Result<HttpResponse, Error>
 where
-    A: Actor<Context = WebsocketContext<A>>
-        + StreamHandler<Result<Message, ProtocolError>>,
+    A: Actor<Context = WebsocketContext<A>> + StreamHandler<Result<Message, ProtocolError>>,
     T: Stream<Item = Result<Bytes, PayloadError>> + 'static,
 {
     let mut res = handshake(req)?;
     Ok(res.streaming(WebsocketContext::create(actor, stream)))
 }
 
-/// Do websocket handshake and start ws actor.
+/// Perform WebSocket handshake and start actor.
 ///
 /// `req` is an HTTP Request that should be requesting a websocket protocol
 /// change. `stream` should be a `Bytes` stream (such as
@@ -48,15 +48,14 @@ where
 ///
 /// If successful, returns a pair where the first item is an address for the
 /// created actor and the second item is the response that should be returned
-/// from the websocket request.
+/// from the WebSocket request.
 pub fn start_with_addr<A, T>(
     actor: A,
     req: &HttpRequest,
     stream: T,
 ) -> Result<(Addr<A>, HttpResponse), Error>
 where
-    A: Actor<Context = WebsocketContext<A>>
-        + StreamHandler<Result<Message, ProtocolError>>,
+    A: Actor<Context = WebsocketContext<A>> + StreamHandler<Result<Message, ProtocolError>>,
     T: Stream<Item = Result<Bytes, PayloadError>> + 'static,
 {
     let mut res = handshake(req)?;
@@ -64,7 +63,7 @@ where
     Ok((addr, res.streaming(out_stream)))
 }
 
-/// Do websocket handshake and start ws actor.
+/// Do WebSocket handshake and start ws actor.
 ///
 /// `protocols` is a sequence of known protocols.
 pub fn start_with_protocols<A, T>(
@@ -74,15 +73,14 @@ pub fn start_with_protocols<A, T>(
     stream: T,
 ) -> Result<HttpResponse, Error>
 where
-    A: Actor<Context = WebsocketContext<A>>
-        + StreamHandler<Result<Message, ProtocolError>>,
+    A: Actor<Context = WebsocketContext<A>> + StreamHandler<Result<Message, ProtocolError>>,
     T: Stream<Item = Result<Bytes, PayloadError>> + 'static,
 {
     let mut res = handshake_with_protocols(req, protocols)?;
     Ok(res.streaming(WebsocketContext::create(actor, stream)))
 }
 
-/// Prepare `WebSocket` handshake response.
+/// Prepare WebSocket handshake response.
 ///
 /// This function returns handshake `HttpResponse`, ready to send to peer.
 /// It does not perform any IO.
@@ -90,7 +88,7 @@ pub fn handshake(req: &HttpRequest) -> Result<HttpResponseBuilder, HandshakeErro
     handshake_with_protocols(req, &[])
 }
 
-/// Prepare `WebSocket` handshake response.
+/// Prepare WebSocket handshake response.
 ///
 /// This function returns handshake `HttpResponse`, ready to send to peer.
 /// It does not perform any IO.
@@ -107,7 +105,7 @@ pub fn handshake_with_protocols(
         return Err(HandshakeError::GetMethodRequired);
     }
 
-    // Check for "UPGRADE" to websocket header
+    // check for "UPGRADE" to WebSocket header
     let has_hdr = if let Some(hdr) = req.headers().get(&header::UPGRADE) {
         if let Ok(s) = hdr.to_str() {
             s.to_ascii_lowercase().contains("websocket")
@@ -164,12 +162,11 @@ pub fn handshake_with_protocols(
 
     let mut response = HttpResponse::build(StatusCode::SWITCHING_PROTOCOLS)
         .upgrade("websocket")
-        .header(header::TRANSFER_ENCODING, "chunked")
-        .header(header::SEC_WEBSOCKET_ACCEPT, key.as_str())
+        .insert_header((header::SEC_WEBSOCKET_ACCEPT, key))
         .take();
 
     if let Some(protocol) = protocol {
-        response.header(&header::SEC_WEBSOCKET_PROTOCOL, protocol);
+        response.insert_header((header::SEC_WEBSOCKET_PROTOCOL, protocol));
     }
 
     Ok(response)
@@ -300,10 +297,7 @@ where
     }
 
     /// Create a new Websocket context
-    pub fn with_factory<S, F>(
-        stream: S,
-        f: F,
-    ) -> impl Stream<Item = Result<Bytes, Error>>
+    pub fn with_factory<S, F>(stream: S, f: F) -> impl Stream<Item = Result<Bytes, Error>>
     where
         F: FnOnce(&mut Self) -> A + 'static,
         A: StreamHandler<Result<Message, ProtocolError>>,
@@ -339,13 +333,13 @@ where
 
     /// Send text frame
     #[inline]
-    pub fn text<T: Into<String>>(&mut self, text: T) {
+    pub fn text(&mut self, text: impl Into<ByteString>) {
         self.write_raw(Message::Text(text.into()));
     }
 
     /// Send binary frame
     #[inline]
-    pub fn binary<B: Into<Bytes>>(&mut self, data: B) {
+    pub fn binary(&mut self, data: impl Into<Bytes>) {
         self.write_raw(Message::Binary(data.into()));
     }
 
@@ -422,10 +416,7 @@ where
 {
     type Item = Result<Bytes, Error>;
 
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         let this = self.get_mut();
 
         if this.fut.alive() {
@@ -492,10 +483,7 @@ where
 {
     type Item = Result<Message, ProtocolError>;
 
-    fn poll_next(
-        mut self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         let mut this = self.as_mut().project();
 
         if !*this.closed {
@@ -511,9 +499,10 @@ where
                     }
                     Poll::Pending => break,
                     Poll::Ready(Some(Err(e))) => {
-                        return Poll::Ready(Some(Err(ProtocolError::Io(
-                            io::Error::new(io::ErrorKind::Other, format!("{}", e)),
-                        ))));
+                        return Poll::Ready(Some(Err(ProtocolError::Io(io::Error::new(
+                            io::ErrorKind::Other,
+                            format!("{}", e),
+                        )))));
                     }
                 }
             }
@@ -529,16 +518,14 @@ where
             }
             Some(frm) => {
                 let msg = match frm {
-                    Frame::Text(data) => Message::Text(
-                        std::str::from_utf8(&data)
-                            .map_err(|e| {
-                                ProtocolError::Io(io::Error::new(
-                                    io::ErrorKind::Other,
-                                    format!("{}", e),
-                                ))
-                            })?
-                            .to_string(),
-                    ),
+                    Frame::Text(data) => {
+                        Message::Text(ByteString::try_from(data).map_err(|e| {
+                            ProtocolError::Io(io::Error::new(
+                                io::ErrorKind::Other,
+                                format!("{}", e),
+                            ))
+                        })?)
+                    }
                     Frame::Binary(data) => Message::Binary(data),
                     Frame::Ping(s) => Message::Ping(s),
                     Frame::Pong(s) => Message::Pong(s),
@@ -574,7 +561,7 @@ mod tests {
         );
 
         let req = TestRequest::default()
-            .header(header::UPGRADE, header::HeaderValue::from_static("test"))
+            .insert_header((header::UPGRADE, header::HeaderValue::from_static("test")))
             .to_http_request();
         assert_eq!(
             HandshakeError::NoWebsocketUpgrade,
@@ -582,10 +569,10 @@ mod tests {
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
+            ))
             .to_http_request();
         assert_eq!(
             HandshakeError::NoConnectionUpgrade,
@@ -593,14 +580,14 @@ mod tests {
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
+            ))
             .to_http_request();
         assert_eq!(
             HandshakeError::NoVersionHeader,
@@ -608,18 +595,18 @@ mod tests {
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_VERSION,
                 header::HeaderValue::from_static("5"),
-            )
+            ))
             .to_http_request();
         assert_eq!(
             HandshakeError::UnsupportedVersion,
@@ -627,18 +614,18 @@ mod tests {
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_VERSION,
                 header::HeaderValue::from_static("13"),
-            )
+            ))
             .to_http_request();
         assert_eq!(
             HandshakeError::BadWebsocketKey,
@@ -646,50 +633,50 @@ mod tests {
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_VERSION,
                 header::HeaderValue::from_static("13"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_KEY,
                 header::HeaderValue::from_static("13"),
-            )
+            ))
             .to_http_request();
 
-        assert_eq!(
-            StatusCode::SWITCHING_PROTOCOLS,
-            handshake(&req).unwrap().finish().status()
-        );
+        let resp = handshake(&req).unwrap().finish();
+        assert_eq!(StatusCode::SWITCHING_PROTOCOLS, resp.status());
+        assert_eq!(None, resp.headers().get(&header::CONTENT_LENGTH));
+        assert_eq!(None, resp.headers().get(&header::TRANSFER_ENCODING));
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_VERSION,
                 header::HeaderValue::from_static("13"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_KEY,
                 header::HeaderValue::from_static("13"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_PROTOCOL,
                 header::HeaderValue::from_static("graphql"),
-            )
+            ))
             .to_http_request();
 
         let protocols = ["graphql"];
@@ -711,26 +698,26 @@ mod tests {
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_VERSION,
                 header::HeaderValue::from_static("13"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_KEY,
                 header::HeaderValue::from_static("13"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_PROTOCOL,
                 header::HeaderValue::from_static("p1, p2, p3"),
-            )
+            ))
             .to_http_request();
 
         let protocols = vec!["p3", "p2"];
@@ -752,26 +739,26 @@ mod tests {
         );
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::UPGRADE,
                 header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONNECTION,
                 header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_VERSION,
                 header::HeaderValue::from_static("13"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_KEY,
                 header::HeaderValue::from_static("13"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::SEC_WEBSOCKET_PROTOCOL,
                 header::HeaderValue::from_static("p1,p2,p3"),
-            )
+            ))
             .to_http_request();
 
         let protocols = vec!["p3", "p2"];
diff --git a/actix-web-actors/tests/test_ws.rs b/actix-web-actors/tests/test_ws.rs
index dda9f6f0b..912480ae4 100644
--- a/actix-web-actors/tests/test_ws.rs
+++ b/actix-web-actors/tests/test_ws.rs
@@ -11,17 +11,13 @@ impl Actor for Ws {
 }
 
 impl StreamHandler<Result<ws::Message, ws::ProtocolError>> for Ws {
-    fn handle(
-        &mut self,
-        msg: Result<ws::Message, ws::ProtocolError>,
-        ctx: &mut Self::Context,
-    ) {
+    fn handle(&mut self, msg: Result<ws::Message, ws::ProtocolError>, ctx: &mut Self::Context) {
         match msg.unwrap() {
             ws::Message::Ping(msg) => ctx.pong(&msg),
             ws::Message::Text(text) => ctx.text(text),
             ws::Message::Binary(bin) => ctx.binary(bin),
             ws::Message::Close(reason) => ctx.close(reason),
-            _ => (),
+            _ => {}
         }
     }
 }
@@ -30,18 +26,13 @@ impl StreamHandler<Result<ws::Message, ws::ProtocolError>> for Ws {
 async fn test_simple() {
     let mut srv = test::start(|| {
         App::new().service(web::resource("/").to(
-            |req: HttpRequest, stream: web::Payload| async move {
-                ws::start(Ws, &req, stream)
-            },
+            |req: HttpRequest, stream: web::Payload| async move { ws::start(Ws, &req, stream) },
         ))
     });
 
     // client service
     let mut framed = srv.ws().await.unwrap();
-    framed
-        .send(ws::Message::Text("text".to_string()))
-        .await
-        .unwrap();
+    framed.send(ws::Message::Text("text".into())).await.unwrap();
 
     let item = framed.next().await.unwrap().unwrap();
     assert_eq!(item, ws::Frame::Text(Bytes::from_static(b"text")));
diff --git a/actix-web-codegen/CHANGES.md b/actix-web-codegen/CHANGES.md
index ad1a22b88..2ce728aad 100644
--- a/actix-web-codegen/CHANGES.md
+++ b/actix-web-codegen/CHANGES.md
@@ -1,11 +1,15 @@
 # Changes
 
-## Unreleased - 2020-xx-xx
+## Unreleased - 2021-xx-xx
+
+
+## 0.5.0-beta.1 - 2021-02-10
+* Use new call signature for `System::new`.
 
 
 ## 0.4.0 - 2020-09-20
 * Added compile success and failure testing. [#1677]
-* Add `route` macro for supporting multiple HTTP methods guards.
+* Add `route` macro for supporting multiple HTTP methods guards. [#1674]
 
 [#1677]: https://github.com/actix/actix-web/pull/1677
 [#1674]: https://github.com/actix/actix-web/pull/1674
@@ -21,47 +25,48 @@
 [#1559]: https://github.com/actix/actix-web/pull/1559
 
 
-## [0.2.2] - 2020-05-23
+## 0.2.2 - 2020-05-23
 * Add resource middleware on actix-web-codegen [#1467]
 
 [#1467]: https://github.com/actix/actix-web/pull/1467
 
-## [0.2.1] - 2020-02-25
+
+## 0.2.1 - 2020-02-25
 * Add `#[allow(missing_docs)]` attribute to generated structs [#1368]
 * Allow the handler function to be named as `config` [#1290]
 
 [#1368]: https://github.com/actix/actix-web/issues/1368
 [#1290]: https://github.com/actix/actix-web/issues/1290
 
-## [0.2.0] - 2019-12-13
 
+## 0.2.0 - 2019-12-13
 * Generate code for actix-web 2.0
 
-## [0.1.3] - 2019-10-14
 
+## 0.1.3 - 2019-10-14
 * Bump up `syn` & `quote` to 1.0
 * Provide better error message
 
-## [0.1.2] - 2019-06-04
 
+## 0.1.2 - 2019-06-04
 * Add macros for head, options, trace, connect and patch http methods
 
-## [0.1.1] - 2019-06-01
 
+## 0.1.1 - 2019-06-01
 * Add syn "extra-traits" feature
 
-## [0.1.0] - 2019-05-18
 
+## 0.1.0 - 2019-05-18
 * Release
 
-## [0.1.0-beta.1] - 2019-04-20
 
+## 0.1.0-beta.1 - 2019-04-20
 * Gen code for actix-web 1.0.0-beta.1
 
-## [0.1.0-alpha.6] - 2019-04-14
 
+## 0.1.0-alpha.6 - 2019-04-14
 * Gen code for actix-web 1.0.0-alpha.6
 
-## [0.1.0-alpha.1] - 2019-03-28
 
+## 0.1.0-alpha.1 - 2019-03-28
 * Initial impl
diff --git a/actix-web-codegen/Cargo.toml b/actix-web-codegen/Cargo.toml
index fd99a8376..886d9ac3e 100644
--- a/actix-web-codegen/Cargo.toml
+++ b/actix-web-codegen/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "actix-web-codegen"
-version = "0.4.0"
-description = "Actix web proc macros"
+version = "0.5.0-beta.1"
+description = "Routing and runtime macros for Actix Web"
 readme = "README.md"
 homepage = "https://actix.rs"
 repository = "https://github.com/actix/actix-web"
@@ -19,8 +19,8 @@ syn = { version = "1", features = ["full", "parsing"] }
 proc-macro2 = "1"
 
 [dev-dependencies]
-actix-rt = "1.1.1"
-actix-web = "3.0.0"
-futures-util = { version = "0.3.5", default-features = false }
+actix-rt = "2"
+actix-web = "4.0.0-beta.3"
+futures-util = { version = "0.3.7", default-features = false }
 trybuild = "1"
 rustversion = "1"
diff --git a/actix-web-codegen/README.md b/actix-web-codegen/README.md
index 6eca847b8..5820bb443 100644
--- a/actix-web-codegen/README.md
+++ b/actix-web-codegen/README.md
@@ -1,22 +1,24 @@
 # actix-web-codegen
 
-> Helper and convenience macros for Actix Web
+> Routing and runtime macros for Actix Web.
 
-[![crates.io](https://meritbadge.herokuapp.com/actix-web-codegen)](https://crates.io/crates/actix-web-codegen)
-[![Documentation](https://docs.rs/actix-web-codegen/badge.svg)](https://docs.rs/actix-web)
-[![Version](https://img.shields.io/badge/rustc-1.42+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.42.html)
-[![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web)
-[![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web)
+[![crates.io](https://img.shields.io/crates/v/actix-web-codegen?label=latest)](https://crates.io/crates/actix-web-codegen)
+[![Documentation](https://docs.rs/actix-web-codegen/badge.svg?version=0.5.0-beta.1)](https://docs.rs/actix-web-codegen/0.5.0-beta.1)
+[![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
+![License](https://img.shields.io/crates/l/actix-web-codegen.svg)
+<br />
+[![dependency status](https://deps.rs/crate/actix-web-codegen/0.5.0-beta.1/status.svg)](https://deps.rs/crate/actix-web-codegen/0.5.0-beta.1)
+[![Download](https://img.shields.io/crates/d/actix-web-codegen.svg)](https://crates.io/crates/actix-web-codegen)
 [![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 ## Documentation & Resources
 
 - [API Documentation](https://docs.rs/actix-web-codegen)
 - [Chat on Gitter](https://gitter.im/actix/actix-web)
-- Cargo package: [actix-web-codegen](https://crates.io/crates/actix-web-codegen)
-- Minimum supported Rust version: 1.42 or later.
+- Minimum supported Rust version: 1.46 or later.
 
 ## Compile Testing
+
 Uses the [`trybuild`] crate. All compile fail tests should include a stderr file generated by `trybuild`. See the [workflow section](https://github.com/dtolnay/trybuild#workflow) of the trybuild docs for info on how to do this.
 
 [`trybuild`]: https://github.com/dtolnay/trybuild
diff --git a/actix-web-codegen/src/lib.rs b/actix-web-codegen/src/lib.rs
index af2bc7f18..670d82ce9 100644
--- a/actix-web-codegen/src/lib.rs
+++ b/actix-web-codegen/src/lib.rs
@@ -1,6 +1,6 @@
-//! Macros for reducing boilerplate code in Actix Web applications.
+//! Routing and runtime macros for Actix Web.
 //!
-//! ## Actix Web Re-exports
+//! # Actix Web Re-exports
 //! Actix Web re-exports a version of this crate in it's entirety so you usually don't have to
 //! specify a dependency on this crate explicitly. Sometimes, however, updates are made to this
 //! crate before the actix-web dependency is updated. Therefore, code examples here will show
@@ -8,9 +8,9 @@
 //! are re-exported.
 //!
 //! # Runtime Setup
-//! Used for setting up the actix async runtime. See [main] macro docs.
+//! Used for setting up the actix async runtime. See [macro@main] macro docs.
 //!
-//! ```rust
+//! ```
 //! #[actix_web_codegen::main] // or `#[actix_web::main]` in Actix Web apps
 //! async fn main() {
 //!     async { println!("Hello world"); }.await
@@ -23,7 +23,7 @@
 //!
 //! See docs for: [GET], [POST], [PATCH], [PUT], [DELETE], [HEAD], [CONNECT], [OPTIONS], [TRACE]
 //!
-//! ```rust
+//! ```
 //! # use actix_web::HttpResponse;
 //! # use actix_web_codegen::get;
 //! #[get("/test")]
@@ -34,9 +34,9 @@
 //!
 //! # Multiple Method Handlers
 //! Similar to the single method handler macro but takes one or more arguments for the HTTP methods
-//! it should respond to. See [route] macro docs.
+//! it should respond to. See [macro@route] macro docs.
 //!
-//! ```rust
+//! ```
 //! # use actix_web::HttpResponse;
 //! # use actix_web_codegen::route;
 //! #[route("/test", method="GET", method="HEAD")]
@@ -46,17 +46,15 @@
 //! ```
 //!
 //! [actix-web attributes docs]: https://docs.rs/actix-web/*/actix_web/#attributes
-//! [main]: attr.main.html
-//! [route]: attr.route.html
-//! [GET]: attr.get.html
-//! [POST]: attr.post.html
-//! [PUT]: attr.put.html
-//! [DELETE]: attr.delete.html
-//! [HEAD]: attr.head.html
-//! [CONNECT]: attr.connect.html
-//! [OPTIONS]: attr.options.html
-//! [TRACE]: attr.trace.html
-//! [PATCH]: attr.patch.html
+//! [GET]: macro@get
+//! [POST]: macro@post
+//! [PUT]: macro@put
+//! [HEAD]: macro@head
+//! [CONNECT]: macro@macro@connect
+//! [OPTIONS]: macro@options
+//! [TRACE]: macro@trace
+//! [PATCH]: macro@patch
+//! [DELETE]: macro@delete
 
 #![recursion_limit = "512"]
 
@@ -161,7 +159,7 @@ method_macro! {
 /// # Actix Web Re-export
 /// This macro can be applied with `#[actix_web::main]` when used in Actix Web applications.
 ///
-/// # Usage
+/// # Examples
 /// ```rust
 /// #[actix_web_codegen::main]
 /// async fn main() {
@@ -177,7 +175,6 @@ pub fn main(_: TokenStream, item: TokenStream) -> TokenStream {
     let vis = &input.vis;
     let sig = &mut input.sig;
     let body = &input.block;
-    let name = &sig.ident;
 
     if sig.asyncness.is_none() {
         return syn::Error::new_spanned(sig.fn_token, "only async fn is supported")
@@ -190,7 +187,7 @@ pub fn main(_: TokenStream, item: TokenStream) -> TokenStream {
     (quote! {
         #(#attrs)*
         #vis #sig {
-            actix_web::rt::System::new(stringify!(#name))
+            actix_web::rt::System::new()
                 .block_on(async move { #body })
         }
     })
diff --git a/actix-web-codegen/tests/test_macro.rs b/actix-web-codegen/tests/test_macro.rs
index dd2bccd7f..34cdad649 100644
--- a/actix-web-codegen/tests/test_macro.rs
+++ b/actix-web-codegen/tests/test_macro.rs
@@ -1,14 +1,11 @@
 use std::future::Future;
-use std::pin::Pin;
 use std::task::{Context, Poll};
 
 use actix_web::dev::{Service, ServiceRequest, ServiceResponse, Transform};
 use actix_web::http::header::{HeaderName, HeaderValue};
 use actix_web::{http, test, web::Path, App, Error, HttpResponse, Responder};
-use actix_web_codegen::{
-    connect, delete, get, head, options, patch, post, put, route, trace,
-};
-use futures_util::future;
+use actix_web_codegen::{connect, delete, get, head, options, patch, post, put, route, trace};
+use futures_util::future::{self, LocalBoxFuture};
 
 // Make sure that we can name function as 'config'
 #[get("/config")]
@@ -88,17 +85,16 @@ async fn route_test() -> impl Responder {
 
 pub struct ChangeStatusCode;
 
-impl<S, B> Transform<S> for ChangeStatusCode
+impl<S, B> Transform<S, ServiceRequest> for ChangeStatusCode
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
     S::Future: 'static,
     B: 'static,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<B>;
     type Error = Error;
-    type InitError = ();
     type Transform = ChangeStatusCodeMiddleware<S>;
+    type InitError = ();
     type Future = future::Ready<Result<Self::Transform, Self::InitError>>;
 
     fn new_transform(&self, service: S) -> Self::Future {
@@ -110,23 +106,21 @@ pub struct ChangeStatusCodeMiddleware<S> {
     service: S,
 }
 
-impl<S, B> Service for ChangeStatusCodeMiddleware<S>
+impl<S, B> Service<ServiceRequest> for ChangeStatusCodeMiddleware<S>
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
     S::Future: 'static,
     B: 'static,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<B>;
     type Error = Error;
-    #[allow(clippy::type_complexity)]
-    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>>>>;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         self.service.poll_ready(cx)
     }
 
-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
+    fn call(&self, req: ServiceRequest) -> Self::Future {
         let fut = self.service.call(req);
 
         Box::pin(async move {
diff --git a/actix-web-codegen/tests/trybuild.rs b/actix-web-codegen/tests/trybuild.rs
index 1bc2bd25e..d2d8a38f5 100644
--- a/actix-web-codegen/tests/trybuild.rs
+++ b/actix-web-codegen/tests/trybuild.rs
@@ -6,22 +6,15 @@ fn compile_macros() {
     t.compile_fail("tests/trybuild/simple-fail.rs");
 
     t.pass("tests/trybuild/route-ok.rs");
+    t.compile_fail("tests/trybuild/route-missing-method-fail.rs");
     t.compile_fail("tests/trybuild/route-duplicate-method-fail.rs");
     t.compile_fail("tests/trybuild/route-unexpected-method-fail.rs");
-
-    test_route_missing_method(&t)
 }
 
-#[rustversion::stable(1.42)]
-fn test_route_missing_method(t: &trybuild::TestCases) {
-    t.compile_fail("tests/trybuild/route-missing-method-fail-msrv.rs");
-}
+// #[rustversion::not(nightly)]
+// fn skip_on_nightly(t: &trybuild::TestCases) {
+//
+// }
 
-#[rustversion::not(stable(1.42))]
-#[rustversion::not(nightly)]
-fn test_route_missing_method(t: &trybuild::TestCases) {
-    t.compile_fail("tests/trybuild/route-missing-method-fail.rs");
-}
-
-#[rustversion::nightly]
-fn test_route_missing_method(_t: &trybuild::TestCases) {}
+// #[rustversion::nightly]
+// fn skip_on_nightly(_t: &trybuild::TestCases) {}
diff --git a/actix-web-codegen/tests/trybuild/route-missing-method-fail-msrv.rs b/actix-web-codegen/tests/trybuild/route-missing-method-fail-msrv.rs
deleted file mode 120000
index 70a5c0e33..000000000
--- a/actix-web-codegen/tests/trybuild/route-missing-method-fail-msrv.rs
+++ /dev/null
@@ -1 +0,0 @@
-route-missing-method-fail.rs
\ No newline at end of file
diff --git a/actix-web-codegen/tests/trybuild/route-missing-method-fail-msrv.stderr b/actix-web-codegen/tests/trybuild/route-missing-method-fail-msrv.stderr
deleted file mode 100644
index d3e2b60ae..000000000
--- a/actix-web-codegen/tests/trybuild/route-missing-method-fail-msrv.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-error: The #[route(..)] macro requires at least one `method` attribute
- --> $DIR/route-missing-method-fail-msrv.rs:3:1
-  |
-3 | #[route("/")]
-  | ^^^^^^^^^^^^^
-
-error[E0425]: cannot find value `index` in this scope
-  --> $DIR/route-missing-method-fail-msrv.rs:12:49
-   |
-12 |     let srv = test::start(|| App::new().service(index));
-   |                                                 ^^^^^ not found in this scope
diff --git a/awc/CHANGES.md b/awc/CHANGES.md
index 07a469746..e6ead2cc8 100644
--- a/awc/CHANGES.md
+++ b/awc/CHANGES.md
@@ -1,6 +1,74 @@
 # Changes
 
-## Unreleased - 2020-xx-xx
+## Unreleased - 2021-xx-xx
+### Added
+* `ClientResponse::timeout` for set the timeout of collecting response body. [#1931]
+
+### Changed
+* Feature `cookies` is now optional and enabled by default. [#1981]
+* `ClientBuilder::connector` method would take `actix_http::client::Connector<T, U>` type. [#2008]
+
+### Removed
+* `ClientBuilder::default` function [#2008]
+* `ClientBuilder::disable_redirects` and `ClientBuilder::max_redirects` method [#2008]
+
+[#1931]: https://github.com/actix/actix-web/pull/1931
+[#1981]: https://github.com/actix/actix-web/pull/1981
+[#2008]: https://github.com/actix/actix-web/pull/2008
+
+## 3.0.0-beta.2 - 2021-02-10
+### Added
+* `ClientRequest::insert_header` method which allows using typed headers. [#1869]
+* `ClientRequest::append_header` method which allows using typed headers. [#1869]
+* `trust-dns` optional feature to enable `trust-dns-resolver` as client dns resolver. [#1969]
+
+### Changed
+* Relax default timeout for `Connector` to 5 seconds(original 1 second). [#1905]
+
+### Removed
+* `ClientRequest::set`; use `ClientRequest::insert_header`. [#1869]
+* `ClientRequest::set_header`; use `ClientRequest::insert_header`. [#1869]
+* `ClientRequest::set_header_if_none`; use `ClientRequest::insert_header_if_none`. [#1869]
+* `ClientRequest::header`; use `ClientRequest::append_header`. [#1869]
+
+[#1869]: https://github.com/actix/actix-web/pull/1869
+[#1905]: https://github.com/actix/actix-web/pull/1905
+[#1969]: https://github.com/actix/actix-web/pull/1969
+
+
+## 3.0.0-beta.1 - 2021-01-07
+### Changed
+* Update `rand` to `0.8`
+* Update `bytes` to `1.0`. [#1813]
+* Update `rust-tls` to `0.19`. [#1813]
+
+[#1813]: https://github.com/actix/actix-web/pull/1813
+
+
+## 2.0.3 - 2020-11-29
+### Fixed
+* Ensure `actix-http` dependency uses same `serde_urlencoded`.
+
+
+## 2.0.2 - 2020-11-25
+### Changed
+* Upgrade `serde_urlencoded` to `0.7`. [#1773]
+
+[#1773]: https://github.com/actix/actix-web/pull/1773
+
+
+## 2.0.1 - 2020-10-30
+### Changed
+* Upgrade `base64` to `0.13`. [#1744]
+* Deprecate `ClientRequest::{if_some, if_true}`. [#1760]
+
+### Fixed
+* Use `Accept-Encoding: identity` instead of `Accept-Encoding: br` when no compression feature
+  is enabled [#1737]
+
+[#1737]: https://github.com/actix/actix-web/pull/1737
+[#1760]: https://github.com/actix/actix-web/pull/1760
+[#1744]: https://github.com/actix/actix-web/pull/1744
 
 
 ## 2.0.0 - 2020-09-11
diff --git a/awc/Cargo.toml b/awc/Cargo.toml
index c67b6ba6f..9beecc6d4 100644
--- a/awc/Cargo.toml
+++ b/awc/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "awc"
-version = "2.0.0"
+version = "3.0.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
-description = "Async HTTP client library that uses the Actix runtime."
+description = "Async HTTP and WebSocket client library built on the Actix ecosystem"
 readme = "README.md"
 keywords = ["actix", "http", "framework", "async", "web"]
 homepage = "https://actix.rs"
@@ -22,50 +22,65 @@ name = "awc"
 path = "src/lib.rs"
 
 [package.metadata.docs.rs]
-features = ["openssl", "rustls", "compress"]
+# features that docs.rs will build with
+features = ["openssl", "rustls", "compress", "cookies"]
 
 [features]
-default = ["compress"]
+default = ["compress", "cookies"]
 
 # openssl
-openssl = ["open-ssl", "actix-http/openssl"]
+openssl = ["tls-openssl", "actix-http/openssl"]
 
 # rustls
-rustls = ["rust-tls", "actix-http/rustls"]
+rustls = ["tls-rustls", "actix-http/rustls"]
 
 # content-encoding support
 compress = ["actix-http/compress"]
 
-[dependencies]
-actix-codec = "0.3.0"
-actix-service = "1.0.6"
-actix-http = "2.0.0"
-actix-rt = "1.0.0"
+# cookie parsing and cookie jar
+cookies = ["actix-http/cookies"]
 
-base64 = "0.12"
-bytes = "0.5.3"
-derive_more = "0.99.2"
-futures-core = { version = "0.3.5", default-features = false }
+# trust-dns as dns resolver
+trust-dns = ["actix-http/trust-dns"]
+
+[dependencies]
+actix-codec = "0.4.0-beta.1"
+actix-service = "2.0.0-beta.4"
+actix-http = "3.0.0-beta.3"
+actix-rt = "2"
+
+base64 = "0.13"
+bytes = "1"
+cfg-if = "1.0"
+derive_more = "0.99.5"
+futures-core = { version = "0.3.7", default-features = false }
 log =" 0.4"
 mime = "0.3"
 percent-encoding = "2.1"
-rand = "0.7"
+rand = "0.8"
 serde = "1.0"
 serde_json = "1.0"
-serde_urlencoded = "0.6.1"
-open-ssl = { version = "0.10", package = "openssl", optional = true }
-rust-tls = { version = "0.18.0", package = "rustls", optional = true, features = ["dangerous_configuration"] }
+serde_urlencoded = "0.7"
+tls-openssl = { version = "0.10.9", package = "openssl", optional = true }
+tls-rustls = { version = "0.19.0", package = "rustls", optional = true, features = ["dangerous_configuration"] }
+
+[target.'cfg(windows)'.dependencies.tls-openssl]
+version = "0.10.9"
+package = "openssl"
+features = ["vendored"]
+optional = true
 
 [dev-dependencies]
-actix-connect = { version = "2.0.0", features = ["openssl"] }
-actix-web = { version = "3.0.0", features = ["openssl"] }
-actix-http = { version = "2.0.0", features = ["openssl"] }
-actix-http-test = { version = "2.0.0", features = ["openssl"] }
-actix-utils = "2.0.0"
-actix-server = "1.0.0"
-actix-tls = { version = "2.0.0", features = ["openssl", "rustls"] }
+actix-web = { version = "4.0.0-beta.3", features = ["openssl"] }
+actix-http = { version = "3.0.0-beta.3", features = ["openssl"] }
+actix-http-test = { version = "3.0.0-beta.2", features = ["openssl"] }
+actix-utils = "3.0.0-beta.1"
+actix-server = "2.0.0-beta.3"
+actix-tls = { version = "3.0.0-beta.3", features = ["openssl", "rustls"] }
+
 brotli2 = "0.3.2"
 flate2 = "1.0.13"
-futures-util = { version = "0.3.5", default-features = false }
-env_logger = "0.7"
+futures-util = { version = "0.3.7", default-features = false }
+env_logger = "0.8"
+rcgen = "0.8"
 webpki = "0.21"
diff --git a/awc/README.md b/awc/README.md
index 2b6309c1d..043ae6a41 100644
--- a/awc/README.md
+++ b/awc/README.md
@@ -1,33 +1,36 @@
-# Actix http client [![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web) [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) [![crates.io](https://meritbadge.herokuapp.com/awc)](https://crates.io/crates/awc) [![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+# awc (Actix Web Client)
 
-An HTTP Client
+> Async HTTP and WebSocket client library.
 
-## Documentation & community resources
+[![crates.io](https://img.shields.io/crates/v/awc?label=latest)](https://crates.io/crates/awc)
+[![Documentation](https://docs.rs/awc/badge.svg?version=3.0.0-beta.2)](https://docs.rs/awc/3.0.0-beta.2)
+![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/awc)
+[![Dependency Status](https://deps.rs/crate/awc/3.0.0-beta.2/status.svg)](https://deps.rs/crate/awc/3.0.0-beta.2)
+[![Join the chat at https://gitter.im/actix/actix-web](https://badges.gitter.im/actix/actix-web.svg)](https://gitter.im/actix/actix-web?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
-* [User Guide](https://actix.rs/docs/)
-* [API Documentation](https://docs.rs/awc/)
-* [Chat on gitter](https://gitter.im/actix/actix)
-* Cargo package: [awc](https://crates.io/crates/awc)
-* Minimum supported Rust version: 1.40 or later
+## Documentation & Resources
+
+- [API Documentation](https://docs.rs/awc)
+- [Example Project](https://github.com/actix/examples/tree/HEAD/awc_https)
+- [Chat on Gitter](https://gitter.im/actix/actix-web)
+- Minimum Supported Rust Version (MSRV): 1.46.0
 
 ## Example
-
 ```rust
 use actix_rt::System;
 use awc::Client;
-use futures::future::{Future, lazy};
 
 fn main() {
-    System::new("test").block_on(lazy(|| {
-       let mut client = Client::default();
+    System::new().block_on(async {
+        let client = Client::default();
 
-       client.get("http://www.rust-lang.org") // <- Create request builder
-          .header("User-Agent", "Actix-web")
-          .send()                             // <- Send http request
-          .and_then(|response| {              // <- server http response
-               println!("Response: {:?}", response);
-               Ok(())
-          })
-    }));
+        let res = client
+            .get("http://www.rust-lang.org")    // <- Create request builder
+            .header("User-Agent", "Actix-web")
+            .send()                             // <- Send http request
+            .await;
+
+        println!("Response: {:?}", res);        // <- server http response
+    });
 }
 ```
diff --git a/awc/src/builder.rs b/awc/src/builder.rs
index 7cd659c38..4495b39fd 100644
--- a/awc/src/builder.rs
+++ b/awc/src/builder.rs
@@ -1,63 +1,82 @@
-use std::cell::RefCell;
 use std::convert::TryFrom;
 use std::fmt;
 use std::rc::Rc;
 use std::time::Duration;
 
-use actix_http::client::{Connect as HttpConnect, ConnectError, Connection, Connector};
-use actix_http::http::{self, header, Error as HttpError, HeaderMap, HeaderName};
+use actix_codec::{AsyncRead, AsyncWrite};
+use actix_http::{
+    client::{Connector, TcpConnect, TcpConnectError, TcpConnection},
+    http::{self, header, Error as HttpError, HeaderMap, HeaderName, Uri},
+};
+use actix_rt::net::TcpStream;
 use actix_service::Service;
 
-use crate::connect::{Connect, ConnectorWrapper};
+use crate::connect::ConnectorWrapper;
 use crate::{Client, ClientConfig};
 
 /// An HTTP Client builder
 ///
 /// This type can be used to construct an instance of `Client` through a
 /// builder-like pattern.
-pub struct ClientBuilder {
+pub struct ClientBuilder<T = (), U = ()> {
     default_headers: bool,
-    allow_redirects: bool,
-    max_redirects: usize,
     max_http_version: Option<http::Version>,
     stream_window_size: Option<u32>,
     conn_window_size: Option<u32>,
     headers: HeaderMap,
     timeout: Option<Duration>,
-    connector: Option<RefCell<Box<dyn Connect>>>,
-}
-
-impl Default for ClientBuilder {
-    fn default() -> Self {
-        Self::new()
-    }
+    connector: Connector<T, U>,
 }
 
 impl ClientBuilder {
-    pub fn new() -> Self {
+    #[allow(clippy::new_ret_no_self)]
+    pub fn new() -> ClientBuilder<
+        impl Service<
+                TcpConnect<Uri>,
+                Response = TcpConnection<Uri, TcpStream>,
+                Error = TcpConnectError,
+            > + Clone,
+        TcpStream,
+    > {
         ClientBuilder {
             default_headers: true,
-            allow_redirects: true,
-            max_redirects: 10,
             headers: HeaderMap::new(),
             timeout: Some(Duration::from_secs(5)),
-            connector: None,
+            connector: Connector::new(),
             max_http_version: None,
             stream_window_size: None,
             conn_window_size: None,
         }
     }
+}
 
+impl<S, Io> ClientBuilder<S, Io>
+where
+    S: Service<TcpConnect<Uri>, Response = TcpConnection<Uri, Io>, Error = TcpConnectError>
+        + Clone
+        + 'static,
+    Io: AsyncRead + AsyncWrite + Unpin + fmt::Debug + 'static,
+{
     /// Use custom connector service.
-    pub fn connector<T>(mut self, connector: T) -> Self
+    pub fn connector<S1, Io1>(self, connector: Connector<S1, Io1>) -> ClientBuilder<S1, Io1>
     where
-        T: Service<Request = HttpConnect, Error = ConnectError> + 'static,
-        T::Response: Connection,
-        <T::Response as Connection>::Future: 'static,
-        T::Future: 'static,
+        S1: Service<
+                TcpConnect<Uri>,
+                Response = TcpConnection<Uri, Io1>,
+                Error = TcpConnectError,
+            > + Clone
+            + 'static,
+        Io1: AsyncRead + AsyncWrite + Unpin + fmt::Debug + 'static,
     {
-        self.connector = Some(RefCell::new(Box::new(ConnectorWrapper(connector))));
-        self
+        ClientBuilder {
+            default_headers: self.default_headers,
+            headers: self.headers,
+            timeout: self.timeout,
+            connector,
+            max_http_version: self.max_http_version,
+            stream_window_size: self.stream_window_size,
+            conn_window_size: self.conn_window_size,
+        }
     }
 
     /// Set request timeout
@@ -75,16 +94,9 @@ impl ClientBuilder {
         self
     }
 
-    /// Do not follow redirects.
+    /// Maximum supported HTTP major version.
     ///
-    /// Redirects are allowed by default.
-    pub fn disable_redirects(mut self) -> Self {
-        self.allow_redirects = false;
-        self
-    }
-
-    /// Maximum supported http major version
-    /// Supported versions http/1.1, http/2
+    /// Supported versions are HTTP/1.1 and HTTP/2.
     pub fn max_http_version(mut self, val: http::Version) -> Self {
         self.max_http_version = Some(val);
         self
@@ -108,14 +120,6 @@ impl ClientBuilder {
         self
     }
 
-    /// Set max number of redirects.
-    ///
-    /// Max redirects is set to 10 by default.
-    pub fn max_redirects(mut self, num: usize) -> Self {
-        self.max_redirects = num;
-        self
-    }
-
     /// Do not add default request headers.
     /// By default `Date` and `User-Agent` headers are set.
     pub fn no_default_headers(mut self) -> Self {
@@ -133,7 +137,7 @@ impl ClientBuilder {
         V::Error: fmt::Debug,
     {
         match HeaderName::try_from(key) {
-            Ok(key) => match value.try_into() {
+            Ok(key) => match value.try_into_value() {
                 Ok(value) => {
                     self.headers.append(key, value);
                 }
@@ -145,9 +149,9 @@ impl ClientBuilder {
     }
 
     /// Set client wide HTTP basic authorization header
-    pub fn basic_auth<U>(self, username: U, password: Option<&str>) -> Self
+    pub fn basic_auth<N>(self, username: N, password: Option<&str>) -> Self
     where
-        U: fmt::Display,
+        N: fmt::Display,
     {
         let auth = match password {
             Some(password) => format!("{}:{}", username, password),
@@ -169,28 +173,24 @@ impl ClientBuilder {
 
     /// Finish build process and create `Client` instance.
     pub fn finish(self) -> Client {
-        let connector = if let Some(connector) = self.connector {
-            connector
-        } else {
-            let mut connector = Connector::new();
-            if let Some(val) = self.max_http_version {
-                connector = connector.max_http_version(val)
-            };
-            if let Some(val) = self.conn_window_size {
-                connector = connector.initial_connection_window_size(val)
-            };
-            if let Some(val) = self.stream_window_size {
-                connector = connector.initial_window_size(val)
-            };
-            RefCell::new(
-                Box::new(ConnectorWrapper(connector.finish())) as Box<dyn Connect>
-            )
+        let mut connector = self.connector;
+
+        if let Some(val) = self.max_http_version {
+            connector = connector.max_http_version(val);
         };
+        if let Some(val) = self.conn_window_size {
+            connector = connector.initial_connection_window_size(val)
+        };
+        if let Some(val) = self.stream_window_size {
+            connector = connector.initial_window_size(val)
+        };
+
         let config = ClientConfig {
             headers: self.headers,
             timeout: self.timeout,
-            connector,
+            connector: Box::new(ConnectorWrapper::new(connector.finish())) as _,
         };
+
         Client(Rc::new(config))
     }
 }
diff --git a/awc/src/connect.rs b/awc/src/connect.rs
index 7fbe1543a..97af2d1cc 100644
--- a/awc/src/connect.rs
+++ b/awc/src/connect.rs
@@ -1,193 +1,115 @@
-use std::future::Future;
-use std::pin::Pin;
-use std::rc::Rc;
-use std::task::{Context, Poll};
-use std::{fmt, io, mem, net};
-
-use actix_codec::{AsyncRead, AsyncWrite, Framed};
-use actix_http::body::Body;
-use actix_http::client::{
-    Connect as ClientConnect, ConnectError, Connection, SendRequestError,
+use std::{
+    fmt, io, net,
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use actix_codec::{AsyncRead, AsyncWrite, Framed, ReadBuf};
+use actix_http::{
+    body::Body,
+    client::{Connect as ClientConnect, ConnectError, Connection, SendRequestError},
+    h1::ClientCodec,
+    RequestHead, RequestHeadType, ResponseHead,
 };
-use actix_http::h1::ClientCodec;
-use actix_http::http::HeaderMap;
-use actix_http::{RequestHead, RequestHeadType, ResponseHead};
 use actix_service::Service;
+use futures_core::future::LocalBoxFuture;
 
 use crate::response::ClientResponse;
 
-pub(crate) struct ConnectorWrapper<T>(pub T);
-
-pub(crate) trait Connect {
-    fn send_request(
-        &mut self,
-        head: RequestHead,
-        body: Body,
-        addr: Option<net::SocketAddr>,
-    ) -> Pin<Box<dyn Future<Output = Result<ClientResponse, SendRequestError>>>>;
-
-    fn send_request_extra(
-        &mut self,
-        head: Rc<RequestHead>,
-        extra_headers: Option<HeaderMap>,
-        body: Body,
-        addr: Option<net::SocketAddr>,
-    ) -> Pin<Box<dyn Future<Output = Result<ClientResponse, SendRequestError>>>>;
-
-    /// Send request, returns Response and Framed
-    fn open_tunnel(
-        &mut self,
-        head: RequestHead,
-        addr: Option<net::SocketAddr>,
-    ) -> Pin<
-        Box<
-            dyn Future<
-                Output = Result<
-                    (ResponseHead, Framed<BoxedSocket, ClientCodec>),
-                    SendRequestError,
-                >,
-            >,
-        >,
-    >;
-
-    /// Send request and extra headers, returns Response and Framed
-    fn open_tunnel_extra(
-        &mut self,
-        head: Rc<RequestHead>,
-        extra_headers: Option<HeaderMap>,
-        addr: Option<net::SocketAddr>,
-    ) -> Pin<
-        Box<
-            dyn Future<
-                Output = Result<
-                    (ResponseHead, Framed<BoxedSocket, ClientCodec>),
-                    SendRequestError,
-                >,
-            >,
-        >,
-    >;
+pub(crate) struct ConnectorWrapper<T> {
+    connector: T,
 }
 
-impl<T> Connect for ConnectorWrapper<T>
+impl<T> ConnectorWrapper<T> {
+    pub(crate) fn new(connector: T) -> Self {
+        Self { connector }
+    }
+}
+
+pub type ConnectService = Box<
+    dyn Service<
+        ConnectRequest,
+        Response = ConnectResponse,
+        Error = SendRequestError,
+        Future = LocalBoxFuture<'static, Result<ConnectResponse, SendRequestError>>,
+    >,
+>;
+
+pub enum ConnectRequest {
+    Client(RequestHeadType, Body, Option<net::SocketAddr>),
+    Tunnel(RequestHead, Option<net::SocketAddr>),
+}
+
+pub enum ConnectResponse {
+    Client(ClientResponse),
+    Tunnel(ResponseHead, Framed<BoxedSocket, ClientCodec>),
+}
+
+impl ConnectResponse {
+    pub fn into_client_response(self) -> ClientResponse {
+        match self {
+            ConnectResponse::Client(res) => res,
+            _ => panic!(
+                "ClientResponse only reachable with ConnectResponse::ClientResponse variant"
+            ),
+        }
+    }
+
+    pub fn into_tunnel_response(self) -> (ResponseHead, Framed<BoxedSocket, ClientCodec>) {
+        match self {
+            ConnectResponse::Tunnel(head, framed) => (head, framed),
+            _ => panic!(
+                "TunnelResponse only reachable with ConnectResponse::TunnelResponse variant"
+            ),
+        }
+    }
+}
+
+impl<T> Service<ConnectRequest> for ConnectorWrapper<T>
 where
-    T: Service<Request = ClientConnect, Error = ConnectError>,
+    T: Service<ClientConnect, Error = ConnectError>,
     T::Response: Connection,
     <T::Response as Connection>::Io: 'static,
-    <T::Response as Connection>::Future: 'static,
-    <T::Response as Connection>::TunnelFuture: 'static,
     T::Future: 'static,
 {
-    fn send_request(
-        &mut self,
-        head: RequestHead,
-        body: Body,
-        addr: Option<net::SocketAddr>,
-    ) -> Pin<Box<dyn Future<Output = Result<ClientResponse, SendRequestError>>>> {
+    type Response = ConnectResponse;
+    type Error = SendRequestError;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
+
+    actix_service::forward_ready!(connector);
+
+    fn call(&self, req: ConnectRequest) -> Self::Future {
         // connect to the host
-        let fut = self.0.call(ClientConnect {
-            uri: head.uri.clone(),
-            addr,
-        });
+        let fut = match req {
+            ConnectRequest::Client(ref head, .., addr) => self.connector.call(ClientConnect {
+                uri: head.as_ref().uri.clone(),
+                addr,
+            }),
+            ConnectRequest::Tunnel(ref head, addr) => self.connector.call(ClientConnect {
+                uri: head.uri.clone(),
+                addr,
+            }),
+        };
 
         Box::pin(async move {
             let connection = fut.await?;
 
-            // send request
-            connection
-                .send_request(RequestHeadType::from(head), body)
-                .await
-                .map(|(head, payload)| ClientResponse::new(head, payload))
-        })
-    }
+            match req {
+                ConnectRequest::Client(head, body, ..) => {
+                    // send request
+                    let (head, payload) = connection.send_request(head, body).await?;
 
-    fn send_request_extra(
-        &mut self,
-        head: Rc<RequestHead>,
-        extra_headers: Option<HeaderMap>,
-        body: Body,
-        addr: Option<net::SocketAddr>,
-    ) -> Pin<Box<dyn Future<Output = Result<ClientResponse, SendRequestError>>>> {
-        // connect to the host
-        let fut = self.0.call(ClientConnect {
-            uri: head.uri.clone(),
-            addr,
-        });
+                    Ok(ConnectResponse::Client(ClientResponse::new(head, payload)))
+                }
+                ConnectRequest::Tunnel(head, ..) => {
+                    // send request
+                    let (head, framed) =
+                        connection.open_tunnel(RequestHeadType::from(head)).await?;
 
-        Box::pin(async move {
-            let connection = fut.await?;
-
-            // send request
-            let (head, payload) = connection
-                .send_request(RequestHeadType::Rc(head, extra_headers), body)
-                .await?;
-
-            Ok(ClientResponse::new(head, payload))
-        })
-    }
-
-    fn open_tunnel(
-        &mut self,
-        head: RequestHead,
-        addr: Option<net::SocketAddr>,
-    ) -> Pin<
-        Box<
-            dyn Future<
-                Output = Result<
-                    (ResponseHead, Framed<BoxedSocket, ClientCodec>),
-                    SendRequestError,
-                >,
-            >,
-        >,
-    > {
-        // connect to the host
-        let fut = self.0.call(ClientConnect {
-            uri: head.uri.clone(),
-            addr,
-        });
-
-        Box::pin(async move {
-            let connection = fut.await?;
-
-            // send request
-            let (head, framed) =
-                connection.open_tunnel(RequestHeadType::from(head)).await?;
-
-            let framed = framed.into_map_io(|io| BoxedSocket(Box::new(Socket(io))));
-            Ok((head, framed))
-        })
-    }
-
-    fn open_tunnel_extra(
-        &mut self,
-        head: Rc<RequestHead>,
-        extra_headers: Option<HeaderMap>,
-        addr: Option<net::SocketAddr>,
-    ) -> Pin<
-        Box<
-            dyn Future<
-                Output = Result<
-                    (ResponseHead, Framed<BoxedSocket, ClientCodec>),
-                    SendRequestError,
-                >,
-            >,
-        >,
-    > {
-        // connect to the host
-        let fut = self.0.call(ClientConnect {
-            uri: head.uri.clone(),
-            addr,
-        });
-
-        Box::pin(async move {
-            let connection = fut.await?;
-
-            // send request
-            let (head, framed) = connection
-                .open_tunnel(RequestHeadType::Rc(head, extra_headers))
-                .await?;
-
-            let framed = framed.into_map_io(|io| BoxedSocket(Box::new(Socket(io))));
-            Ok((head, framed))
+                    let framed = framed.into_map_io(|io| BoxedSocket(Box::new(Socket(io))));
+                    Ok(ConnectResponse::Tunnel(head, framed))
+                }
+            }
         })
     }
 }
@@ -221,18 +143,11 @@ impl fmt::Debug for BoxedSocket {
 }
 
 impl AsyncRead for BoxedSocket {
-    unsafe fn prepare_uninitialized_buffer(
-        &self,
-        buf: &mut [mem::MaybeUninit<u8>],
-    ) -> bool {
-        self.0.as_read().prepare_uninitialized_buffer(buf)
-    }
-
     fn poll_read(
         self: Pin<&mut Self>,
         cx: &mut Context<'_>,
-        buf: &mut [u8],
-    ) -> Poll<io::Result<usize>> {
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
         Pin::new(self.get_mut().0.as_read_mut()).poll_read(cx, buf)
     }
 }
@@ -250,10 +165,7 @@ impl AsyncWrite for BoxedSocket {
         Pin::new(self.get_mut().0.as_write()).poll_flush(cx)
     }
 
-    fn poll_shutdown(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<io::Result<()>> {
+    fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
         Pin::new(self.get_mut().0.as_write()).poll_shutdown(cx)
     }
 }
diff --git a/awc/src/error.rs b/awc/src/error.rs
index d008166d9..f86224e62 100644
--- a/awc/src/error.rs
+++ b/awc/src/error.rs
@@ -1,7 +1,6 @@
-//! Http client errors
-pub use actix_http::client::{
-    ConnectError, FreezeRequestError, InvalidUrl, SendRequestError,
-};
+//! HTTP client errors
+
+pub use actix_http::client::{ConnectError, FreezeRequestError, InvalidUrl, SendRequestError};
 pub use actix_http::error::PayloadError;
 pub use actix_http::http::Error as HttpError;
 pub use actix_http::ws::HandshakeError as WsHandshakeError;
diff --git a/awc/src/frozen.rs b/awc/src/frozen.rs
index f7098863c..46b4063a0 100644
--- a/awc/src/frozen.rs
+++ b/awc/src/frozen.rs
@@ -144,8 +144,10 @@ impl FrozenSendBuilder {
         V: IntoHeaderValue,
     {
         match HeaderName::try_from(key) {
-            Ok(key) => match value.try_into() {
-                Ok(value) => self.extra_headers.insert(key, value),
+            Ok(key) => match value.try_into_value() {
+                Ok(value) => {
+                    self.extra_headers.insert(key, value);
+                }
                 Err(e) => self.err = Some(e.into()),
             },
             Err(e) => self.err = Some(e.into()),
diff --git a/awc/src/lib.rs b/awc/src/lib.rs
index 45c52092a..66ff55402 100644
--- a/awc/src/lib.rs
+++ b/awc/src/lib.rs
@@ -1,20 +1,13 @@
-#![deny(rust_2018_idioms)]
-#![allow(
-    clippy::type_complexity,
-    clippy::borrow_interior_mutable_const,
-    clippy::needless_doctest_main
-)]
-
-//! `awc` is a HTTP and WebSocket client library built using the Actix ecosystem.
+//! `awc` is a HTTP and WebSocket client library built on the Actix ecosystem.
 //!
 //! ## Making a GET request
 //!
-//! ```rust
+//! ```no_run
 //! # #[actix_rt::main]
 //! # async fn main() -> Result<(), awc::error::SendRequestError> {
 //! let mut client = awc::Client::default();
 //! let response = client.get("http://www.rust-lang.org") // <- Create request builder
-//!     .header("User-Agent", "Actix-web")
+//!     .insert_header(("User-Agent", "Actix-web"))
 //!     .send()                                            // <- Send http request
 //!     .await?;
 //!
@@ -27,7 +20,7 @@
 //!
 //! ### Raw body contents
 //!
-//! ```rust
+//! ```no_run
 //! # #[actix_rt::main]
 //! # async fn main() -> Result<(), awc::error::SendRequestError> {
 //! let mut client = awc::Client::default();
@@ -40,7 +33,7 @@
 //!
 //! ### Forms
 //!
-//! ```rust
+//! ```no_run
 //! # #[actix_rt::main]
 //! # async fn main() -> Result<(), awc::error::SendRequestError> {
 //! let params = [("foo", "bar"), ("baz", "quux")];
@@ -55,7 +48,7 @@
 //!
 //! ### JSON
 //!
-//! ```rust
+//! ```no_run
 //! # #[actix_rt::main]
 //! # async fn main() -> Result<(), awc::error::SendRequestError> {
 //! let request = serde_json::json!({
@@ -73,7 +66,7 @@
 //!
 //! ## WebSocket support
 //!
-//! ```
+//! ```no_run
 //! # #[actix_rt::main]
 //! # async fn main() -> Result<(), Box<dyn std::error::Error>> {
 //! use futures_util::{sink::SinkExt, stream::StreamExt};
@@ -83,7 +76,7 @@
 //!     .await?;
 //!
 //! connection
-//!     .send(awc::ws::Message::Text("Echo".to_string()))
+//!     .send(awc::ws::Message::Text("Echo".into()))
 //!     .await?;
 //! let response = connection.next().await.unwrap()?;
 //! # assert_eq!(response, awc::ws::Frame::Text("Echo".as_bytes().into()));
@@ -91,15 +84,30 @@
 //! # }
 //! ```
 
-use std::cell::RefCell;
+#![deny(rust_2018_idioms)]
+#![allow(
+    clippy::type_complexity,
+    clippy::borrow_interior_mutable_const,
+    clippy::needless_doctest_main
+)]
+#![doc(html_logo_url = "https://actix.rs/img/logo.png")]
+#![doc(html_favicon_url = "https://actix.rs/favicon.ico")]
+
 use std::convert::TryFrom;
 use std::rc::Rc;
 use std::time::Duration;
 
-pub use actix_http::{client::Connector, cookie, http};
+#[cfg(feature = "cookies")]
+pub use actix_http::cookie;
+pub use actix_http::{client::Connector, http};
 
-use actix_http::http::{Error as HttpError, HeaderMap, Method, Uri};
-use actix_http::RequestHead;
+use actix_http::{
+    client::{TcpConnect, TcpConnectError, TcpConnection},
+    http::{Error as HttpError, HeaderMap, Method, Uri},
+    RequestHead,
+};
+use actix_rt::net::TcpStream;
+use actix_service::Service;
 
 mod builder;
 mod connect;
@@ -112,13 +120,13 @@ pub mod test;
 pub mod ws;
 
 pub use self::builder::ClientBuilder;
-pub use self::connect::BoxedSocket;
+pub use self::connect::{BoxedSocket, ConnectRequest, ConnectResponse, ConnectService};
 pub use self::frozen::{FrozenClientRequest, FrozenSendBuilder};
 pub use self::request::ClientRequest;
 pub use self::response::{ClientResponse, JsonBody, MessageBody};
 pub use self::sender::SendClientRequest;
 
-use self::connect::{Connect, ConnectorWrapper};
+use self::connect::ConnectorWrapper;
 
 /// An asynchronous HTTP and WebSocket client.
 ///
@@ -132,8 +140,8 @@ use self::connect::{Connect, ConnectorWrapper};
 ///     let mut client = Client::default();
 ///
 ///     let res = client.get("http://www.rust-lang.org") // <- Create request builder
-///         .header("User-Agent", "Actix-web")
-///         .send()                             // <- Send http request
+///         .insert_header(("User-Agent", "Actix-web"))
+///         .send()                             // <- Send HTTP request
 ///         .await;                             // <- send request and wait for response
 ///
 ///      println!("Response: {:?}", res);
@@ -143,7 +151,7 @@ use self::connect::{Connect, ConnectorWrapper};
 pub struct Client(Rc<ClientConfig>);
 
 pub(crate) struct ClientConfig {
-    pub(crate) connector: RefCell<Box<dyn Connect>>,
+    pub(crate) connector: ConnectService,
     pub(crate) headers: HeaderMap,
     pub(crate) timeout: Option<Duration>,
 }
@@ -151,9 +159,7 @@ pub(crate) struct ClientConfig {
 impl Default for Client {
     fn default() -> Self {
         Client(Rc::new(ClientConfig {
-            connector: RefCell::new(Box::new(ConnectorWrapper(
-                Connector::new().finish(),
-            ))),
+            connector: Box::new(ConnectorWrapper::new(Connector::new().finish())),
             headers: HeaderMap::new(),
             timeout: Some(Duration::from_secs(5)),
         }))
@@ -168,7 +174,14 @@ impl Client {
 
     /// Create `Client` builder.
     /// This function is equivalent of `ClientBuilder::new()`.
-    pub fn builder() -> ClientBuilder {
+    pub fn builder() -> ClientBuilder<
+        impl Service<
+                TcpConnect<Uri>,
+                Response = TcpConnection<Uri, TcpStream>,
+                Error = TcpConnectError,
+            > + Clone,
+        TcpStream,
+    > {
         ClientBuilder::new()
     }
 
@@ -180,8 +193,8 @@ impl Client {
     {
         let mut req = ClientRequest::new(method, url, self.0.clone());
 
-        for (key, value) in self.0.headers.iter() {
-            req = req.set_header_if_none(key.clone(), value.clone());
+        for header in self.0.headers.iter() {
+            req = req.insert_header_if_none(header);
         }
         req
     }
@@ -196,8 +209,8 @@ impl Client {
         <Uri as TryFrom<U>>::Error: Into<HttpError>,
     {
         let mut req = self.request(head.method.clone(), url);
-        for (key, value) in head.headers.iter() {
-            req = req.set_header_if_none(key.clone(), value.clone());
+        for header in head.headers.iter() {
+            req = req.insert_header_if_none(header);
         }
         req
     }
diff --git a/awc/src/request.rs b/awc/src/request.rs
index dcada2c6d..812c0e805 100644
--- a/awc/src/request.rs
+++ b/awc/src/request.rs
@@ -8,11 +8,11 @@ use futures_core::Stream;
 use serde::Serialize;
 
 use actix_http::body::Body;
+#[cfg(feature = "cookies")]
 use actix_http::cookie::{Cookie, CookieJar};
-use actix_http::http::header::{self, Header, IntoHeaderValue};
+use actix_http::http::header::{self, IntoHeaderPair};
 use actix_http::http::{
-    uri, ConnectionType, Error as HttpError, HeaderMap, HeaderName, HeaderValue, Method,
-    Uri, Version,
+    uri, ConnectionType, Error as HttpError, HeaderMap, HeaderValue, Method, Uri, Version,
 };
 use actix_http::{Error, RequestHead};
 
@@ -21,10 +21,15 @@ use crate::frozen::FrozenClientRequest;
 use crate::sender::{PrepForSendingError, RequestSender, SendClientRequest};
 use crate::ClientConfig;
 
-#[cfg(any(feature = "flate2-zlib", feature = "flate2-rust"))]
-const HTTPS_ENCODING: &str = "br, gzip, deflate";
-#[cfg(not(any(feature = "flate2-zlib", feature = "flate2-rust")))]
-const HTTPS_ENCODING: &str = "br";
+cfg_if::cfg_if! {
+    if #[cfg(any(feature = "flate2-zlib", feature = "flate2-rust"))] {
+        const HTTPS_ENCODING: &str = "br, gzip, deflate";
+    } else if #[cfg(feature = "compress")] {
+        const HTTPS_ENCODING: &str = "br";
+    } else {
+        const HTTPS_ENCODING: &str = "identity";
+    }
+}
 
 /// An HTTP Client request builder
 ///
@@ -32,17 +37,15 @@ const HTTPS_ENCODING: &str = "br";
 /// builder-like pattern.
 ///
 /// ```rust
-/// use actix_rt::System;
-///
 /// #[actix_rt::main]
 /// async fn main() {
 ///    let response = awc::Client::new()
 ///         .get("http://www.rust-lang.org") // <- Create request builder
-///         .header("User-Agent", "Actix-web")
-///         .send()                          // <- Send http request
+///         .insert_header(("User-Agent", "Actix-web"))
+///         .send()                          // <- Send HTTP request
 ///         .await;
 ///
-///    response.and_then(|response| {   // <- server http response
+///    response.and_then(|response| {   // <- server HTTP response
 ///         println!("Response: {:?}", response);
 ///         Ok(())
 ///    });
@@ -52,10 +55,12 @@ pub struct ClientRequest {
     pub(crate) head: RequestHead,
     err: Option<HttpError>,
     addr: Option<net::SocketAddr>,
-    cookies: Option<CookieJar>,
     response_decompress: bool,
     timeout: Option<Duration>,
     config: Rc<ClientConfig>,
+
+    #[cfg(feature = "cookies")]
+    cookies: Option<CookieJar>,
 }
 
 impl ClientRequest {
@@ -70,6 +75,7 @@ impl ClientRequest {
             head: RequestHead::default(),
             err: None,
             addr: None,
+            #[cfg(feature = "cookies")]
             cookies: None,
             timeout: None,
             response_decompress: true,
@@ -138,110 +144,73 @@ impl ClientRequest {
         &self.head.peer_addr
     }
 
-    #[inline]
     /// Returns request's headers.
+    #[inline]
     pub fn headers(&self) -> &HeaderMap {
         &self.head.headers
     }
 
-    #[inline]
     /// Returns request's mutable headers.
+    #[inline]
     pub fn headers_mut(&mut self) -> &mut HeaderMap {
         &mut self.head.headers
     }
 
-    /// Set a header.
-    ///
-    /// ```rust
-    /// fn main() {
-    /// # actix_rt::System::new("test").block_on(futures_util::future::lazy(|_| {
-    ///     let req = awc::Client::new()
-    ///         .get("http://www.rust-lang.org")
-    ///         .set(awc::http::header::Date::now())
-    ///         .set(awc::http::header::ContentType(mime::TEXT_HTML));
-    /// #   Ok::<_, ()>(())
-    /// # }));
-    /// }
-    /// ```
-    pub fn set<H: Header>(mut self, hdr: H) -> Self {
-        match hdr.try_into() {
-            Ok(value) => {
-                self.head.headers.insert(H::name(), value);
+    /// Insert a header, replacing any that were set with an equivalent field name.
+    pub fn insert_header<H>(mut self, header: H) -> Self
+    where
+        H: IntoHeaderPair,
+    {
+        match header.try_into_header_pair() {
+            Ok((key, value)) => {
+                self.head.headers.insert(key, value);
             }
             Err(e) => self.err = Some(e.into()),
-        }
-        self
-    }
+        };
 
-    /// Append a header.
-    ///
-    /// Header gets appended to existing header.
-    /// To override header use `set_header()` method.
-    ///
-    /// ```rust
-    /// use awc::{http, Client};
-    ///
-    /// fn main() {
-    /// # actix_rt::System::new("test").block_on(async {
-    ///     let req = Client::new()
-    ///         .get("http://www.rust-lang.org")
-    ///         .header("X-TEST", "value")
-    ///         .header(http::header::CONTENT_TYPE, "application/json");
-    /// #   Ok::<_, ()>(())
-    /// # });
-    /// }
-    /// ```
-    pub fn header<K, V>(mut self, key: K, value: V) -> Self
-    where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
-    {
-        match HeaderName::try_from(key) {
-            Ok(key) => match value.try_into() {
-                Ok(value) => self.head.headers.append(key, value),
-                Err(e) => self.err = Some(e.into()),
-            },
-            Err(e) => self.err = Some(e.into()),
-        }
-        self
-    }
-
-    /// Insert a header, replaces existing header.
-    pub fn set_header<K, V>(mut self, key: K, value: V) -> Self
-    where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
-    {
-        match HeaderName::try_from(key) {
-            Ok(key) => match value.try_into() {
-                Ok(value) => self.head.headers.insert(key, value),
-                Err(e) => self.err = Some(e.into()),
-            },
-            Err(e) => self.err = Some(e.into()),
-        }
         self
     }
 
     /// Insert a header only if it is not yet set.
-    pub fn set_header_if_none<K, V>(mut self, key: K, value: V) -> Self
+    pub fn insert_header_if_none<H>(mut self, header: H) -> Self
     where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
+        H: IntoHeaderPair,
     {
-        match HeaderName::try_from(key) {
-            Ok(key) => {
+        match header.try_into_header_pair() {
+            Ok((key, value)) => {
                 if !self.head.headers.contains_key(&key) {
-                    match value.try_into() {
-                        Ok(value) => self.head.headers.insert(key, value),
-                        Err(e) => self.err = Some(e.into()),
-                    }
+                    self.head.headers.insert(key, value);
                 }
             }
             Err(e) => self.err = Some(e.into()),
-        }
+        };
+
+        self
+    }
+
+    /// Append a header, keeping any that were set with an equivalent field name.
+    ///
+    /// ```rust
+    /// # #[actix_rt::main]
+    /// # async fn main() {
+    /// # use awc::Client;
+    /// use awc::http::header::ContentType;
+    ///
+    /// Client::new()
+    ///     .get("http://www.rust-lang.org")
+    ///     .insert_header(("X-TEST", "value"))
+    ///     .insert_header(ContentType(mime::APPLICATION_JSON));
+    /// # }
+    /// ```
+    pub fn append_header<H>(mut self, header: H) -> Self
+    where
+        H: IntoHeaderPair,
+    {
+        match header.try_into_header_pair() {
+            Ok((key, value)) => self.head.headers.append(key, value),
+            Err(e) => self.err = Some(e.into()),
+        };
+
         self
     }
 
@@ -253,7 +222,7 @@ impl ClientRequest {
     }
 
     /// Force close connection instead of returning it back to connections pool.
-    /// This setting affect only http/1 connections.
+    /// This setting affect only HTTP/1 connections.
     #[inline]
     pub fn force_close(mut self) -> Self {
         self.head.set_connection_type(ConnectionType::Close);
@@ -268,7 +237,9 @@ impl ClientRequest {
         <HeaderValue as TryFrom<V>>::Error: Into<HttpError>,
     {
         match HeaderValue::try_from(value) {
-            Ok(value) => self.head.headers.insert(header::CONTENT_TYPE, value),
+            Ok(value) => {
+                self.head.headers.insert(header::CONTENT_TYPE, value);
+            }
             Err(e) => self.err = Some(e.into()),
         }
         self
@@ -277,7 +248,7 @@ impl ClientRequest {
     /// Set content length
     #[inline]
     pub fn content_length(self, len: u64) -> Self {
-        self.header(header::CONTENT_LENGTH, len)
+        self.append_header((header::CONTENT_LENGTH, len))
     }
 
     /// Set HTTP basic authorization header
@@ -289,10 +260,10 @@ impl ClientRequest {
             Some(password) => format!("{}:{}", username, password),
             None => format!("{}:", username),
         };
-        self.header(
+        self.append_header((
             header::AUTHORIZATION,
             format!("Basic {}", base64::encode(&auth)),
-        )
+        ))
     }
 
     /// Set HTTP bearer authentication header
@@ -300,7 +271,7 @@ impl ClientRequest {
     where
         T: fmt::Display,
     {
-        self.header(header::AUTHORIZATION, format!("Bearer {}", token))
+        self.append_header((header::AUTHORIZATION, format!("Bearer {}", token)))
     }
 
     /// Set a cookie
@@ -323,6 +294,7 @@ impl ClientRequest {
     ///     println!("Response: {:?}", resp);
     /// }
     /// ```
+    #[cfg(feature = "cookies")]
     pub fn cookie(mut self, cookie: Cookie<'_>) -> Self {
         if self.cookies.is_none() {
             let mut jar = CookieJar::new();
@@ -349,8 +321,9 @@ impl ClientRequest {
         self
     }
 
-    /// This method calls provided closure with builder reference if
-    /// value is `true`.
+    /// This method calls provided closure with builder reference if value is `true`.
+    #[doc(hidden)]
+    #[deprecated = "Use an if statement."]
     pub fn if_true<F>(self, value: bool, f: F) -> Self
     where
         F: FnOnce(ClientRequest) -> ClientRequest,
@@ -362,8 +335,9 @@ impl ClientRequest {
         }
     }
 
-    /// This method calls provided closure with builder reference if
-    /// value is `Some`.
+    /// This method calls provided closure with builder reference if value is `Some`.
+    #[doc(hidden)]
+    #[deprecated = "Use an if-let construction."]
     pub fn if_some<T, F>(self, value: Option<T>, f: F) -> Self
     where
         F: FnOnce(T, ClientRequest) -> ClientRequest,
@@ -503,7 +477,8 @@ impl ClientRequest {
         )
     }
 
-    fn prep_for_sending(mut self) -> Result<Self, PrepForSendingError> {
+    // allow unused mut when cookies feature is disabled
+    fn prep_for_sending(#[allow(unused_mut)] mut self) -> Result<Self, PrepForSendingError> {
         if let Some(e) = self.err {
             return Err(e.into());
         }
@@ -516,7 +491,7 @@ impl ClientRequest {
             return Err(InvalidUrl::MissingScheme.into());
         } else if let Some(scheme) = uri.scheme() {
             match scheme.as_str() {
-                "http" | "ws" | "https" | "wss" => (),
+                "http" | "ws" | "https" | "wss" => {}
                 _ => return Err(InvalidUrl::UnknownScheme.into()),
             }
         } else {
@@ -524,6 +499,7 @@ impl ClientRequest {
         }
 
         // set cookies
+        #[cfg(feature = "cookies")]
         if let Some(ref mut jar) = self.cookies {
             let cookie: String = jar
                 .delta()
@@ -550,12 +526,11 @@ impl ClientRequest {
                 .unwrap_or(true);
 
             if https {
-                slf = slf.set_header_if_none(header::ACCEPT_ENCODING, HTTPS_ENCODING)
+                slf = slf.insert_header_if_none((header::ACCEPT_ENCODING, HTTPS_ENCODING))
             } else {
                 #[cfg(any(feature = "flate2-zlib", feature = "flate2-rust"))]
                 {
-                    slf =
-                        slf.set_header_if_none(header::ACCEPT_ENCODING, "gzip, deflate")
+                    slf = slf.insert_header_if_none((header::ACCEPT_ENCODING, "gzip, deflate"))
                 }
             };
         }
@@ -588,7 +563,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_debug() {
-        let request = Client::new().get("/").header("x-test", "111");
+        let request = Client::new().get("/").append_header(("x-test", "111"));
         let repr = format!("{:?}", request);
         assert!(repr.contains("ClientRequest"));
         assert!(repr.contains("x-test"));
@@ -596,20 +571,27 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_basics() {
-        let mut req = Client::new()
+        let req = Client::new()
             .put("/")
             .version(Version::HTTP_2)
-            .set(header::Date(SystemTime::now().into()))
+            .insert_header(header::Date(SystemTime::now().into()))
             .content_type("plain/text")
-            .if_true(true, |req| req.header(header::SERVER, "awc"))
-            .if_true(false, |req| req.header(header::EXPECT, "awc"))
-            .if_some(Some("server"), |val, req| {
-                req.header(header::USER_AGENT, val)
-            })
-            .if_some(Option::<&str>::None, |_, req| {
-                req.header(header::ALLOW, "1")
-            })
-            .content_length(100);
+            .append_header((header::SERVER, "awc"));
+
+        let req = if let Some(val) = Some("server") {
+            req.append_header((header::USER_AGENT, val))
+        } else {
+            req
+        };
+
+        let req = if let Some(_val) = Option::<&str>::None {
+            req.append_header((header::ALLOW, "1"))
+        } else {
+            req
+        };
+
+        let mut req = req.content_length(100);
+
         assert!(req.headers().contains_key(header::CONTENT_TYPE));
         assert!(req.headers().contains_key(header::DATE));
         assert!(req.headers().contains_key(header::SERVER));
@@ -617,6 +599,7 @@ mod tests {
         assert!(!req.headers().contains_key(header::ALLOW));
         assert!(!req.headers().contains_key(header::EXPECT));
         assert_eq!(req.head.version, Version::HTTP_2);
+
         let _ = req.headers_mut();
         let _ = req.send_body("");
     }
@@ -645,7 +628,7 @@ mod tests {
             .header(header::CONTENT_TYPE, "111")
             .finish()
             .get("/")
-            .set_header(header::CONTENT_TYPE, "222");
+            .insert_header((header::CONTENT_TYPE, "222"));
 
         assert_eq!(
             req.head
diff --git a/awc/src/response.rs b/awc/src/response.rs
index 8364aa556..514b8a90b 100644
--- a/awc/src/response.rs
+++ b/awc/src/response.rs
@@ -1,26 +1,65 @@
-use std::cell::{Ref, RefMut};
-use std::fmt;
-use std::future::Future;
-use std::marker::PhantomData;
-use std::pin::Pin;
-use std::task::{Context, Poll};
+use std::{
+    cell::{Ref, RefMut},
+    fmt,
+    future::Future,
+    io,
+    marker::PhantomData,
+    pin::Pin,
+    task::{Context, Poll},
+    time::{Duration, Instant},
+};
 
+use actix_http::{
+    error::PayloadError,
+    http::{header, HeaderMap, StatusCode, Version},
+    Extensions, HttpMessage, Payload, PayloadStream, ResponseHead,
+};
+use actix_rt::time::{sleep, Sleep};
 use bytes::{Bytes, BytesMut};
 use futures_core::{ready, Stream};
-
-use actix_http::cookie::Cookie;
-use actix_http::error::{CookieParseError, PayloadError};
-use actix_http::http::header::{CONTENT_LENGTH, SET_COOKIE};
-use actix_http::http::{HeaderMap, StatusCode, Version};
-use actix_http::{Extensions, HttpMessage, Payload, PayloadStream, ResponseHead};
 use serde::de::DeserializeOwned;
 
+#[cfg(feature = "cookies")]
+use actix_http::{cookie::Cookie, error::CookieParseError};
+
 use crate::error::JsonPayloadError;
 
 /// Client Response
 pub struct ClientResponse<S = PayloadStream> {
     pub(crate) head: ResponseHead,
     pub(crate) payload: Payload<S>,
+    pub(crate) timeout: ResponseTimeout,
+}
+
+/// helper enum with reusable sleep passed from `SendClientResponse`.
+/// See `ClientResponse::_timeout` for reason.
+pub(crate) enum ResponseTimeout {
+    Disabled(Option<Pin<Box<Sleep>>>),
+    Enabled(Pin<Box<Sleep>>),
+}
+
+impl Default for ResponseTimeout {
+    fn default() -> Self {
+        Self::Disabled(None)
+    }
+}
+
+impl ResponseTimeout {
+    fn poll_timeout(&mut self, cx: &mut Context<'_>) -> Result<(), PayloadError> {
+        match *self {
+            Self::Enabled(ref mut timeout) => {
+                if timeout.as_mut().poll(cx).is_ready() {
+                    Err(PayloadError::Io(io::Error::new(
+                        io::ErrorKind::TimedOut,
+                        "Response Payload IO timed out",
+                    )))
+                } else {
+                    Ok(())
+                }
+            }
+            Self::Disabled(_) => Ok(()),
+        }
+    }
 }
 
 impl<S> HttpMessage for ClientResponse<S> {
@@ -30,6 +69,10 @@ impl<S> HttpMessage for ClientResponse<S> {
         &self.head.headers
     }
 
+    fn take_payload(&mut self) -> Payload<S> {
+        std::mem::replace(&mut self.payload, Payload::None)
+    }
+
     fn extensions(&self) -> Ref<'_, Extensions> {
         self.head.extensions()
     }
@@ -38,20 +81,15 @@ impl<S> HttpMessage for ClientResponse<S> {
         self.head.extensions_mut()
     }
 
-    fn take_payload(&mut self) -> Payload<S> {
-        std::mem::replace(&mut self.payload, Payload::None)
-    }
-
     /// Load request cookies.
-    #[inline]
+    #[cfg(feature = "cookies")]
     fn cookies(&self) -> Result<Ref<'_, Vec<Cookie<'static>>>, CookieParseError> {
         struct Cookies(Vec<Cookie<'static>>);
 
         if self.extensions().get::<Cookies>().is_none() {
             let mut cookies = Vec::new();
-            for hdr in self.headers().get_all(&SET_COOKIE) {
-                let s = std::str::from_utf8(hdr.as_bytes())
-                    .map_err(CookieParseError::from)?;
+            for hdr in self.headers().get_all(&header::SET_COOKIE) {
+                let s = std::str::from_utf8(hdr.as_bytes()).map_err(CookieParseError::from)?;
                 cookies.push(Cookie::parse_encoded(s)?.into_owned());
             }
             self.extensions_mut().insert(Cookies(cookies));
@@ -65,7 +103,11 @@ impl<S> HttpMessage for ClientResponse<S> {
 impl<S> ClientResponse<S> {
     /// Create new Request instance
     pub(crate) fn new(head: ResponseHead, payload: Payload<S>) -> Self {
-        ClientResponse { head, payload }
+        ClientResponse {
+            head,
+            payload,
+            timeout: ResponseTimeout::default(),
+        }
     }
 
     #[inline]
@@ -101,15 +143,50 @@ impl<S> ClientResponse<S> {
         ClientResponse {
             payload,
             head: self.head,
+            timeout: self.timeout,
         }
     }
+
+    /// Set a timeout duration for [`ClientResponse`](self::ClientResponse).
+    ///
+    /// This duration covers the duration of processing the response body stream
+    /// and would end it as timeout error when deadline met.
+    ///
+    /// Disabled by default.
+    pub fn timeout(self, dur: Duration) -> Self {
+        let timeout = match self.timeout {
+            ResponseTimeout::Disabled(Some(mut timeout))
+            | ResponseTimeout::Enabled(mut timeout) => match Instant::now().checked_add(dur) {
+                Some(deadline) => {
+                    timeout.as_mut().reset(deadline.into());
+                    ResponseTimeout::Enabled(timeout)
+                }
+                None => ResponseTimeout::Enabled(Box::pin(sleep(dur))),
+            },
+            _ => ResponseTimeout::Enabled(Box::pin(sleep(dur))),
+        };
+
+        Self {
+            payload: self.payload,
+            head: self.head,
+            timeout,
+        }
+    }
+
+    /// This method does not enable timeout. It's used to pass the boxed `Sleep` from
+    /// `SendClientRequest` and reuse it's heap allocation together with it's slot in
+    /// timer wheel.
+    pub(crate) fn _timeout(mut self, timeout: Option<Pin<Box<Sleep>>>) -> Self {
+        self.timeout = ResponseTimeout::Disabled(timeout);
+        self
+    }
 }
 
 impl<S> ClientResponse<S>
 where
     S: Stream<Item = Result<Bytes, PayloadError>>,
 {
-    /// Loads http response's body.
+    /// Loads HTTP response's body.
     pub fn body(&mut self) -> MessageBody<S> {
         MessageBody::new(self)
     }
@@ -132,11 +209,11 @@ where
 {
     type Item = Result<Bytes, PayloadError>;
 
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
-        Pin::new(&mut self.get_mut().payload).poll_next(cx)
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        let this = self.get_mut();
+        this.timeout.poll_timeout(cx)?;
+
+        Pin::new(&mut this.payload).poll_next(cx)
     }
 }
 
@@ -151,10 +228,11 @@ impl<S> fmt::Debug for ClientResponse<S> {
     }
 }
 
-/// Future that resolves to a complete http message body.
+/// Future that resolves to a complete HTTP message body.
 pub struct MessageBody<S> {
     length: Option<usize>,
     err: Option<PayloadError>,
+    timeout: ResponseTimeout,
     fut: Option<ReadBody<S>>,
 }
 
@@ -165,7 +243,7 @@ where
     /// Create `MessageBody` for request.
     pub fn new(res: &mut ClientResponse<S>) -> MessageBody<S> {
         let mut len = None;
-        if let Some(l) = res.headers().get(&CONTENT_LENGTH) {
+        if let Some(l) = res.headers().get(&header::CONTENT_LENGTH) {
             if let Ok(s) = l.to_str() {
                 if let Ok(l) = s.parse::<usize>() {
                     len = Some(l)
@@ -180,11 +258,12 @@ where
         MessageBody {
             length: len,
             err: None,
+            timeout: std::mem::take(&mut res.timeout),
             fut: Some(ReadBody::new(res.take_payload(), 262_144)),
         }
     }
 
-    /// Change max size of payload. By default max size is 256Kb
+    /// Change max size of payload. By default max size is 256kB
     pub fn limit(mut self, limit: usize) -> Self {
         if let Some(ref mut fut) = self.fut {
             fut.limit = limit;
@@ -197,6 +276,7 @@ where
             fut: None,
             err: Some(e),
             length: None,
+            timeout: ResponseTimeout::default(),
         }
     }
 }
@@ -220,6 +300,8 @@ where
             }
         }
 
+        this.timeout.poll_timeout(cx)?;
+
         Pin::new(&mut this.fut.as_mut().unwrap()).poll(cx)
     }
 }
@@ -233,8 +315,9 @@ where
 pub struct JsonBody<S, U> {
     length: Option<usize>,
     err: Option<JsonPayloadError>,
+    timeout: ResponseTimeout,
     fut: Option<ReadBody<S>>,
-    _t: PhantomData<U>,
+    _phantom: PhantomData<U>,
 }
 
 impl<S, U> JsonBody<S, U>
@@ -243,9 +326,9 @@ where
     U: DeserializeOwned,
 {
     /// Create `JsonBody` for request.
-    pub fn new(req: &mut ClientResponse<S>) -> Self {
+    pub fn new(res: &mut ClientResponse<S>) -> Self {
         // check content-type
-        let json = if let Ok(Some(mime)) = req.mime_type() {
+        let json = if let Ok(Some(mime)) = res.mime_type() {
             mime.subtype() == mime::JSON || mime.suffix() == Some(mime::JSON)
         } else {
             false
@@ -254,13 +337,15 @@ where
             return JsonBody {
                 length: None,
                 fut: None,
+                timeout: ResponseTimeout::default(),
                 err: Some(JsonPayloadError::ContentType),
-                _t: PhantomData,
+                _phantom: PhantomData,
             };
         }
 
         let mut len = None;
-        if let Some(l) = req.headers().get(&CONTENT_LENGTH) {
+
+        if let Some(l) = res.headers().get(&header::CONTENT_LENGTH) {
             if let Ok(s) = l.to_str() {
                 if let Ok(l) = s.parse::<usize>() {
                     len = Some(l)
@@ -271,12 +356,13 @@ where
         JsonBody {
             length: len,
             err: None,
-            fut: Some(ReadBody::new(req.take_payload(), 65536)),
-            _t: PhantomData,
+            timeout: std::mem::take(&mut res.timeout),
+            fut: Some(ReadBody::new(res.take_payload(), 65536)),
+            _phantom: PhantomData,
         }
     }
 
-    /// Change max size of payload. By default max size is 64Kb
+    /// Change max size of payload. By default max size is 64kB
     pub fn limit(mut self, limit: usize) -> Self {
         if let Some(ref mut fut) = self.fut {
             fut.limit = limit;
@@ -306,12 +392,14 @@ where
 
         if let Some(len) = self.length.take() {
             if len > self.fut.as_ref().unwrap().limit {
-                return Poll::Ready(Err(JsonPayloadError::Payload(
-                    PayloadError::Overflow,
-                )));
+                return Poll::Ready(Err(JsonPayloadError::Payload(PayloadError::Overflow)));
             }
         }
 
+        self.timeout
+            .poll_timeout(cx)
+            .map_err(JsonPayloadError::Payload)?;
+
         let body = ready!(Pin::new(&mut self.get_mut().fut.as_mut().unwrap()).poll(cx))?;
         Poll::Ready(serde_json::from_slice::<U>(&body).map_err(JsonPayloadError::from))
     }
@@ -370,14 +458,13 @@ mod tests {
     async fn test_body() {
         let mut req = TestResponse::with_header(header::CONTENT_LENGTH, "xxxx").finish();
         match req.body().await.err().unwrap() {
-            PayloadError::UnknownLength => (),
+            PayloadError::UnknownLength => {}
             _ => unreachable!("error"),
         }
 
-        let mut req =
-            TestResponse::with_header(header::CONTENT_LENGTH, "1000000").finish();
+        let mut req = TestResponse::with_header(header::CONTENT_LENGTH, "1000000").finish();
         match req.body().await.err().unwrap() {
-            PayloadError::Overflow => (),
+            PayloadError::Overflow => {}
             _ => unreachable!("error"),
         }
 
@@ -390,7 +477,7 @@ mod tests {
             .set_payload(Bytes::from_static(b"11111111111111"))
             .finish();
         match req.body().limit(5).await.err().unwrap() {
-            PayloadError::Overflow => (),
+            PayloadError::Overflow => {}
             _ => unreachable!("error"),
         }
     }
diff --git a/awc/src/sender.rs b/awc/src/sender.rs
index 0bcdf4307..1170c69a0 100644
--- a/awc/src/sender.rs
+++ b/awc/src/sender.rs
@@ -1,28 +1,30 @@
-use std::future::Future;
-use std::net;
-use std::pin::Pin;
-use std::rc::Rc;
-use std::task::{Context, Poll};
-use std::time::Duration;
+use std::{
+    future::Future,
+    net,
+    pin::Pin,
+    rc::Rc,
+    task::{Context, Poll},
+    time::Duration,
+};
 
-use actix_rt::time::{delay_for, Delay};
+use actix_http::{
+    body::{Body, BodyStream},
+    http::{
+        header::{self, HeaderMap, HeaderName, IntoHeaderValue},
+        Error as HttpError,
+    },
+    Error, RequestHead, RequestHeadType,
+};
+use actix_rt::time::{sleep, Sleep};
 use bytes::Bytes;
 use derive_more::From;
 use futures_core::Stream;
 use serde::Serialize;
 
-use actix_http::body::{Body, BodyStream};
-use actix_http::http::header::{self, IntoHeaderValue};
-use actix_http::http::{Error as HttpError, HeaderMap, HeaderName};
-use actix_http::{Error, RequestHead};
-
-#[cfg(feature = "compress")]
-use actix_http::encoding::Decoder;
-#[cfg(feature = "compress")]
-use actix_http::http::header::ContentEncoding;
-#[cfg(feature = "compress")]
-use actix_http::{Payload, PayloadStream};
+#[cfg(feature = "compress")]
+use actix_http::{encoding::Decoder, http::header::ContentEncoding, Payload, PayloadStream};
 
+use crate::connect::{ConnectRequest, ConnectResponse};
 use crate::error::{FreezeRequestError, InvalidUrl, SendRequestError};
 use crate::response::ClientResponse;
 use crate::ClientConfig;
@@ -33,18 +35,18 @@ pub(crate) enum PrepForSendingError {
     Http(HttpError),
 }
 
-impl Into<FreezeRequestError> for PrepForSendingError {
-    fn into(self) -> FreezeRequestError {
-        match self {
+impl From<PrepForSendingError> for FreezeRequestError {
+    fn from(err: PrepForSendingError) -> FreezeRequestError {
+        match err {
             PrepForSendingError::Url(e) => FreezeRequestError::Url(e),
             PrepForSendingError::Http(e) => FreezeRequestError::Http(e),
         }
     }
 }
 
-impl Into<SendRequestError> for PrepForSendingError {
-    fn into(self) -> SendRequestError {
-        match self {
+impl From<PrepForSendingError> for SendRequestError {
+    fn from(err: PrepForSendingError) -> SendRequestError {
+        match err {
             PrepForSendingError::Url(e) => SendRequestError::Url(e),
             PrepForSendingError::Http(e) => SendRequestError::Http(e),
         }
@@ -55,8 +57,9 @@ impl Into<SendRequestError> for PrepForSendingError {
 #[must_use = "futures do nothing unless polled"]
 pub enum SendClientRequest {
     Fut(
-        Pin<Box<dyn Future<Output = Result<ClientResponse, SendRequestError>>>>,
-        Option<Delay>,
+        Pin<Box<dyn Future<Output = Result<ConnectResponse, SendRequestError>>>>,
+        // FIXME: use a pinned Sleep instead of box.
+        Option<Pin<Box<Sleep>>>,
         bool,
     ),
     Err(Option<SendRequestError>),
@@ -64,46 +67,43 @@ pub enum SendClientRequest {
 
 impl SendClientRequest {
     pub(crate) fn new(
-        send: Pin<Box<dyn Future<Output = Result<ClientResponse, SendRequestError>>>>,
+        send: Pin<Box<dyn Future<Output = Result<ConnectResponse, SendRequestError>>>>,
         response_decompress: bool,
         timeout: Option<Duration>,
     ) -> SendClientRequest {
-        let delay = timeout.map(delay_for);
+        let delay = timeout.map(|d| Box::pin(sleep(d)));
         SendClientRequest::Fut(send, delay, response_decompress)
     }
 }
 
 #[cfg(feature = "compress")]
 impl Future for SendClientRequest {
-    type Output =
-        Result<ClientResponse<Decoder<Payload<PayloadStream>>>, SendRequestError>;
+    type Output = Result<ClientResponse<Decoder<Payload<PayloadStream>>>, SendRequestError>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let this = self.get_mut();
 
         match this {
             SendClientRequest::Fut(send, delay, response_decompress) => {
-                if delay.is_some() {
-                    match Pin::new(delay.as_mut().unwrap()).poll(cx) {
-                        Poll::Pending => (),
-                        _ => return Poll::Ready(Err(SendRequestError::Timeout)),
+                if let Some(delay) = delay {
+                    if delay.as_mut().poll(cx).is_ready() {
+                        return Poll::Ready(Err(SendRequestError::Timeout));
                     }
                 }
 
-                let res = futures_core::ready!(Pin::new(send).poll(cx)).map(|res| {
-                    res.map_body(|head, payload| {
-                        if *response_decompress {
-                            Payload::Stream(Decoder::from_headers(
-                                payload,
-                                &head.headers,
-                            ))
-                        } else {
-                            Payload::Stream(Decoder::new(
-                                payload,
-                                ContentEncoding::Identity,
-                            ))
-                        }
-                    })
+                let res = futures_core::ready!(send.as_mut().poll(cx)).map(|res| {
+                    res.into_client_response()._timeout(delay.take()).map_body(
+                        |head, payload| {
+                            if *response_decompress {
+                                Payload::Stream(Decoder::from_headers(payload, &head.headers))
+                            } else {
+                                Payload::Stream(Decoder::new(
+                                    payload,
+                                    ContentEncoding::Identity,
+                                ))
+                            }
+                        },
+                    )
                 });
 
                 Poll::Ready(res)
@@ -124,13 +124,14 @@ impl Future for SendClientRequest {
         let this = self.get_mut();
         match this {
             SendClientRequest::Fut(send, delay, _) => {
-                if delay.is_some() {
-                    match Pin::new(delay.as_mut().unwrap()).poll(cx) {
-                        Poll::Pending => (),
-                        _ => return Poll::Ready(Err(SendRequestError::Timeout)),
+                if let Some(delay) = delay {
+                    if delay.as_mut().poll(cx).is_ready() {
+                        return Poll::Ready(Err(SendRequestError::Timeout));
                     }
                 }
-                Pin::new(send).poll(cx)
+                send.as_mut()
+                    .poll(cx)
+                    .map_ok(|res| res.into_client_response()._timeout(delay.take()))
             }
             SendClientRequest::Err(ref mut e) => match e.take() {
                 Some(e) => Poll::Ready(Err(e)),
@@ -182,17 +183,19 @@ impl RequestSender {
     where
         B: Into<Body>,
     {
-        let mut connector = config.connector.borrow_mut();
-
-        let fut = match self {
+        let req = match self {
             RequestSender::Owned(head) => {
-                connector.send_request(head, body.into(), addr)
-            }
-            RequestSender::Rc(head, extra_headers) => {
-                connector.send_request_extra(head, extra_headers, body.into(), addr)
+                ConnectRequest::Client(RequestHeadType::Owned(head), body.into(), addr)
             }
+            RequestSender::Rc(head, extra_headers) => ConnectRequest::Client(
+                RequestHeadType::Rc(head, extra_headers),
+                body.into(),
+                addr,
+            ),
         };
 
+        let fut = config.connector.call(req);
+
         SendClientRequest::new(fut, response_decompress, timeout.or(config.timeout))
     }
 
@@ -209,8 +212,7 @@ impl RequestSender {
             Err(e) => return Error::from(e).into(),
         };
 
-        if let Err(e) = self.set_header_if_none(header::CONTENT_TYPE, "application/json")
-        {
+        if let Err(e) = self.set_header_if_none(header::CONTENT_TYPE, "application/json") {
             return e.into();
         }
 
@@ -237,10 +239,9 @@ impl RequestSender {
         };
 
         // set content-type
-        if let Err(e) = self.set_header_if_none(
-            header::CONTENT_TYPE,
-            "application/x-www-form-urlencoded",
-        ) {
+        if let Err(e) =
+            self.set_header_if_none(header::CONTENT_TYPE, "application/x-www-form-urlencoded")
+        {
             return e.into();
         }
 
@@ -284,19 +285,17 @@ impl RequestSender {
         self.send_body(addr, response_decompress, timeout, config, Body::Empty)
     }
 
-    fn set_header_if_none<V>(
-        &mut self,
-        key: HeaderName,
-        value: V,
-    ) -> Result<(), HttpError>
+    fn set_header_if_none<V>(&mut self, key: HeaderName, value: V) -> Result<(), HttpError>
     where
         V: IntoHeaderValue,
     {
         match self {
             RequestSender::Owned(head) => {
                 if !head.headers.contains_key(&key) {
-                    match value.try_into() {
-                        Ok(value) => head.headers.insert(key, value),
+                    match value.try_into_value() {
+                        Ok(value) => {
+                            head.headers.insert(key, value);
+                        }
                         Err(e) => return Err(e.into()),
                     }
                 }
@@ -305,7 +304,7 @@ impl RequestSender {
                 if !head.headers.contains_key(&key)
                     && !extra_headers.iter().any(|h| h.contains_key(&key))
                 {
-                    match value.try_into() {
+                    match value.try_into_value() {
                         Ok(v) => {
                             let h = extra_headers.get_or_insert(HeaderMap::new());
                             h.insert(key, v)
diff --git a/awc/src/test.rs b/awc/src/test.rs
index 68e5c9dc5..97bbb9c3d 100644
--- a/awc/src/test.rs
+++ b/awc/src/test.rs
@@ -1,9 +1,13 @@
 //! Test helpers for actix http client to use during testing.
 use std::convert::TryFrom;
 
-use actix_http::cookie::{Cookie, CookieJar};
-use actix_http::http::header::{self, Header, HeaderValue, IntoHeaderValue};
+use actix_http::http::header::{Header, IntoHeaderValue};
 use actix_http::http::{Error as HttpError, HeaderName, StatusCode, Version};
+#[cfg(feature = "cookies")]
+use actix_http::{
+    cookie::{Cookie, CookieJar},
+    http::header::{self, HeaderValue},
+};
 use actix_http::{h1, Payload, ResponseHead};
 use bytes::Bytes;
 
@@ -12,6 +16,7 @@ use crate::ClientResponse;
 /// Test `ClientResponse` builder
 pub struct TestResponse {
     head: ResponseHead,
+    #[cfg(feature = "cookies")]
     cookies: CookieJar,
     payload: Option<Payload>,
 }
@@ -20,6 +25,7 @@ impl Default for TestResponse {
     fn default() -> TestResponse {
         TestResponse {
             head: ResponseHead::new(StatusCode::OK),
+            #[cfg(feature = "cookies")]
             cookies: CookieJar::new(),
             payload: None,
         }
@@ -45,7 +51,7 @@ impl TestResponse {
 
     /// Set a header
     pub fn set<H: Header>(mut self, hdr: H) -> Self {
-        if let Ok(value) = hdr.try_into() {
+        if let Ok(value) = hdr.try_into_value() {
             self.head.headers.append(H::name(), value);
             return self;
         }
@@ -60,7 +66,7 @@ impl TestResponse {
         V: IntoHeaderValue,
     {
         if let Ok(key) = HeaderName::try_from(key) {
-            if let Ok(value) = value.try_into() {
+            if let Ok(value) = value.try_into_value() {
                 self.head.headers.append(key, value);
                 return self;
             }
@@ -69,6 +75,7 @@ impl TestResponse {
     }
 
     /// Set cookie for this response
+    #[cfg(feature = "cookies")]
     pub fn cookie(mut self, cookie: Cookie<'_>) -> Self {
         self.cookies.add(cookie.into_owned());
         self
@@ -84,8 +91,11 @@ impl TestResponse {
 
     /// Complete response creation and generate `ClientResponse` instance
     pub fn finish(self) -> ClientResponse {
+        // allow unused mut when cookies feature is disabled
+        #[allow(unused_mut)]
         let mut head = self.head;
 
+        #[cfg(feature = "cookies")]
         for cookie in self.cookies.delta() {
             head.headers.insert(
                 header::SET_COOKIE,
diff --git a/awc/src/ws.rs b/awc/src/ws.rs
index 57e80bd46..5f4570963 100644
--- a/awc/src/ws.rs
+++ b/awc/src/ws.rs
@@ -1,10 +1,10 @@
 //! Websockets client
 //!
-//! Type definitions required to use [`awc::Client`](../struct.Client.html) as a WebSocket client.
+//! Type definitions required to use [`awc::Client`](super::Client) as a WebSocket client.
 //!
 //! # Example
 //!
-//! ```
+//! ```no_run
 //! use awc::{Client, ws};
 //! use futures_util::{sink::SinkExt, stream::StreamExt};
 //!
@@ -17,7 +17,7 @@
 //!         .unwrap();
 //!
 //!     connection
-//!         .send(ws::Message::Text("Echo".to_string()))
+//!         .send(ws::Message::Text("Echo".into()))
 //!         .await
 //!         .unwrap();
 //!     let response = connection.next().await.unwrap().unwrap();
@@ -32,24 +32,22 @@ use std::rc::Rc;
 use std::{fmt, str};
 
 use actix_codec::Framed;
+#[cfg(feature = "cookies")]
 use actix_http::cookie::{Cookie, CookieJar};
 use actix_http::{ws, Payload, RequestHead};
 use actix_rt::time::timeout;
+use actix_service::Service;
 
 pub use actix_http::ws::{CloseCode, CloseReason, Codec, Frame, Message};
 
-use crate::connect::BoxedSocket;
+use crate::connect::{BoxedSocket, ConnectRequest};
 use crate::error::{InvalidUrl, SendRequestError, WsClientError};
-use crate::http::header::{
-    self, HeaderName, HeaderValue, IntoHeaderValue, AUTHORIZATION,
-};
-use crate::http::{
-    ConnectionType, Error as HttpError, Method, StatusCode, Uri, Version,
-};
+use crate::http::header::{self, HeaderName, HeaderValue, IntoHeaderValue, AUTHORIZATION};
+use crate::http::{ConnectionType, Error as HttpError, Method, StatusCode, Uri, Version};
 use crate::response::ClientResponse;
 use crate::ClientConfig;
 
-/// `WebSocket` connection
+/// WebSocket connection.
 pub struct WebsocketsRequest {
     pub(crate) head: RequestHead,
     err: Option<HttpError>,
@@ -58,21 +56,28 @@ pub struct WebsocketsRequest {
     addr: Option<SocketAddr>,
     max_size: usize,
     server_mode: bool,
-    cookies: Option<CookieJar>,
     config: Rc<ClientConfig>,
+
+    #[cfg(feature = "cookies")]
+    cookies: Option<CookieJar>,
 }
 
 impl WebsocketsRequest {
-    /// Create new websocket connection
+    /// Create new WebSocket connection
     pub(crate) fn new<U>(uri: U, config: Rc<ClientConfig>) -> Self
     where
         Uri: TryFrom<U>,
         <Uri as TryFrom<U>>::Error: Into<HttpError>,
     {
         let mut err = None;
-        let mut head = RequestHead::default();
-        head.method = Method::GET;
-        head.version = Version::HTTP_11;
+
+        #[allow(clippy::field_reassign_with_default)]
+        let mut head = {
+            let mut head = RequestHead::default();
+            head.method = Method::GET;
+            head.version = Version::HTTP_11;
+            head
+        };
 
         match Uri::try_from(uri) {
             Ok(uri) => head.uri = uri,
@@ -88,6 +93,7 @@ impl WebsocketsRequest {
             protocols: None,
             max_size: 65_536,
             server_mode: false,
+            #[cfg(feature = "cookies")]
             cookies: None,
         }
     }
@@ -101,7 +107,7 @@ impl WebsocketsRequest {
         self
     }
 
-    /// Set supported websocket protocols
+    /// Set supported WebSocket protocols
     pub fn protocols<U, V>(mut self, protos: U) -> Self
     where
         U: IntoIterator<Item = V>,
@@ -116,6 +122,7 @@ impl WebsocketsRequest {
     }
 
     /// Set a cookie
+    #[cfg(feature = "cookies")]
     pub fn cookie(mut self, cookie: Cookie<'_>) -> Self {
         if self.cookies.is_none() {
             let mut jar = CookieJar::new();
@@ -142,7 +149,7 @@ impl WebsocketsRequest {
 
     /// Set max frame size
     ///
-    /// By default max size is set to 64kb
+    /// By default max size is set to 64kB
     pub fn max_frame_size(mut self, size: usize) -> Self {
         self.max_size = size;
         self
@@ -165,7 +172,7 @@ impl WebsocketsRequest {
         V: IntoHeaderValue,
     {
         match HeaderName::try_from(key) {
-            Ok(key) => match value.try_into() {
+            Ok(key) => match value.try_into_value() {
                 Ok(value) => {
                     self.head.headers.append(key, value);
                 }
@@ -184,7 +191,7 @@ impl WebsocketsRequest {
         V: IntoHeaderValue,
     {
         match HeaderName::try_from(key) {
-            Ok(key) => match value.try_into() {
+            Ok(key) => match value.try_into_value() {
                 Ok(value) => {
                     self.head.headers.insert(key, value);
                 }
@@ -205,7 +212,7 @@ impl WebsocketsRequest {
         match HeaderName::try_from(key) {
             Ok(key) => {
                 if !self.head.headers.contains_key(&key) {
-                    match value.try_into() {
+                    match value.try_into_value() {
                         Ok(value) => {
                             self.head.headers.insert(key, value);
                         }
@@ -238,7 +245,7 @@ impl WebsocketsRequest {
         self.header(AUTHORIZATION, format!("Bearer {}", token))
     }
 
-    /// Complete request construction and connect to a websockets server.
+    /// Complete request construction and connect to a WebSocket server.
     pub async fn connect(
         mut self,
     ) -> Result<(ClientResponse, Framed<BoxedSocket, Codec>), WsClientError> {
@@ -254,7 +261,7 @@ impl WebsocketsRequest {
             return Err(InvalidUrl::MissingScheme.into());
         } else if let Some(scheme) = uri.scheme() {
             match scheme.as_str() {
-                "http" | "ws" | "https" | "wss" => (),
+                "http" | "ws" | "https" | "wss" => {}
                 _ => return Err(InvalidUrl::UnknownScheme.into()),
             }
         } else {
@@ -269,6 +276,7 @@ impl WebsocketsRequest {
         }
 
         // set cookies
+        #[cfg(feature = "cookies")]
         if let Some(ref mut jar) = self.cookies {
             let cookie: String = jar
                 .delta()
@@ -320,28 +328,27 @@ impl WebsocketsRequest {
         let max_size = self.max_size;
         let server_mode = self.server_mode;
 
-        let fut = self
-            .config
-            .connector
-            .borrow_mut()
-            .open_tunnel(head, self.addr);
+        let req = ConnectRequest::Tunnel(head, self.addr);
+
+        let fut = self.config.connector.call(req);
 
         // set request timeout
-        let (head, framed) = if let Some(to) = self.config.timeout {
+        let res = if let Some(to) = self.config.timeout {
             timeout(to, fut)
                 .await
-                .map_err(|_| SendRequestError::Timeout)
-                .and_then(|res| res)?
+                .map_err(|_| SendRequestError::Timeout)??
         } else {
             fut.await?
         };
 
+        let (head, framed) = res.into_tunnel_response();
+
         // verify response
         if head.status != StatusCode::SWITCHING_PROTOCOLS {
             return Err(WsClientError::InvalidResponseStatus(head.status));
         }
 
-        // Check for "UPGRADE" to websocket header
+        // check for "UPGRADE" to WebSocket header
         let has_hdr = if let Some(hdr) = head.headers.get(&header::UPGRADE) {
             if let Ok(s) = hdr.to_str() {
                 s.to_ascii_lowercase().contains("websocket")
diff --git a/awc/tests/test_client.rs b/awc/tests/test_client.rs
index a9552d0d5..a41a8dac3 100644
--- a/awc/tests/test_client.rs
+++ b/awc/tests/test_client.rs
@@ -9,19 +9,22 @@ use bytes::Bytes;
 use flate2::read::GzDecoder;
 use flate2::write::GzEncoder;
 use flate2::Compression;
-use futures_util::future::ok;
+use futures_util::{future::ok, stream};
 use rand::Rng;
 
-use actix_http::HttpService;
+use actix_http::{
+    http::{self, StatusCode},
+    HttpService,
+};
 use actix_http_test::test_server;
 use actix_service::{map_config, pipeline_factory};
-use actix_web::dev::{AppConfig, BodyEncoding};
-use actix_web::http::Cookie;
-use actix_web::middleware::Compress;
 use actix_web::{
-    http::header, test, web, App, Error, HttpMessage, HttpRequest, HttpResponse,
+    dev::{AppConfig, BodyEncoding},
+    http::{header, Cookie},
+    middleware::Compress,
+    test, web, App, Error, HttpMessage, HttpRequest, HttpResponse,
 };
-use awc::error::SendRequestError;
+use awc::error::{JsonPayloadError, PayloadError, SendRequestError};
 
 const STR: &str = "Hello World Hello World Hello World Hello World Hello World \
                    Hello World Hello World Hello World Hello World Hello World \
@@ -48,11 +51,10 @@ const STR: &str = "Hello World Hello World Hello World Hello World Hello World \
 #[actix_rt::test]
 async fn test_simple() {
     let srv = test::start(|| {
-        App::new()
-            .service(web::resource("/").route(web::to(|| HttpResponse::Ok().body(STR))))
+        App::new().service(web::resource("/").route(web::to(|| HttpResponse::Ok().body(STR))))
     });
 
-    let request = srv.get("/").header("x-test", "111").send();
+    let request = srv.get("/").insert_header(("x-test", "111")).send();
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
 
@@ -82,7 +84,7 @@ async fn test_json() {
 
     let request = srv
         .get("/")
-        .header("x-test", "111")
+        .insert_header(("x-test", "111"))
         .send_json(&"TEST".to_string());
     let response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -99,7 +101,10 @@ async fn test_form() {
     let mut data = HashMap::new();
     let _ = data.insert("key".to_string(), "TEST".to_string());
 
-    let request = srv.get("/").header("x-test", "111").send_form(&data);
+    let request = srv
+        .get("/")
+        .append_header(("x-test", "111"))
+        .send_form(&data);
     let response = request.await.unwrap();
     assert!(response.status().is_success());
 }
@@ -108,17 +113,14 @@ async fn test_form() {
 async fn test_timeout() {
     let srv = test::start(|| {
         App::new().service(web::resource("/").route(web::to(|| async {
-            actix_rt::time::delay_for(Duration::from_millis(200)).await;
+            actix_rt::time::sleep(Duration::from_millis(200)).await;
             Ok::<_, Error>(HttpResponse::Ok().body(STR))
         })))
     });
 
     let connector = awc::Connector::new()
-        .connector(actix_connect::new_connector(
-            actix_connect::start_default_resolver().await.unwrap(),
-        ))
-        .timeout(Duration::from_secs(15))
-        .finish();
+        .connector(actix_tls::connect::default_connector())
+        .timeout(Duration::from_secs(15));
 
     let client = awc::Client::builder()
         .connector(connector)
@@ -127,7 +129,7 @@ async fn test_timeout() {
 
     let request = client.get(srv.url("/")).send();
     match request.await {
-        Err(SendRequestError::Timeout) => (),
+        Err(SendRequestError::Timeout) => {}
         _ => panic!(),
     }
 }
@@ -136,7 +138,7 @@ async fn test_timeout() {
 async fn test_timeout_override() {
     let srv = test::start(|| {
         App::new().service(web::resource("/").route(web::to(|| async {
-            actix_rt::time::delay_for(Duration::from_millis(200)).await;
+            actix_rt::time::sleep(Duration::from_millis(200)).await;
             Ok::<_, Error>(HttpResponse::Ok().body(STR))
         })))
     });
@@ -149,11 +151,84 @@ async fn test_timeout_override() {
         .timeout(Duration::from_millis(50))
         .send();
     match request.await {
-        Err(SendRequestError::Timeout) => (),
+        Err(SendRequestError::Timeout) => {}
         _ => panic!(),
     }
 }
 
+#[actix_rt::test]
+async fn test_response_timeout() {
+    use futures_util::stream::{once, StreamExt};
+
+    let srv = test::start(|| {
+        App::new().service(web::resource("/").route(web::to(|| async {
+            Ok::<_, Error>(
+                HttpResponse::Ok()
+                    .content_type("application/json")
+                    .streaming(Box::pin(once(async {
+                        actix_rt::time::sleep(Duration::from_millis(200)).await;
+                        Ok::<_, Error>(Bytes::from(STR))
+                    }))),
+            )
+        })))
+    });
+
+    let client = awc::Client::new();
+
+    let res = client
+        .get(srv.url("/"))
+        .send()
+        .await
+        .unwrap()
+        .timeout(Duration::from_millis(500))
+        .body()
+        .await
+        .unwrap();
+    assert_eq!(std::str::from_utf8(res.as_ref()).unwrap(), STR);
+
+    let res = client
+        .get(srv.url("/"))
+        .send()
+        .await
+        .unwrap()
+        .timeout(Duration::from_millis(100))
+        .next()
+        .await
+        .unwrap();
+    match res {
+        Err(PayloadError::Io(e)) => assert_eq!(e.kind(), std::io::ErrorKind::TimedOut),
+        _ => panic!("Response error type is not matched"),
+    }
+
+    let res = client
+        .get(srv.url("/"))
+        .send()
+        .await
+        .unwrap()
+        .timeout(Duration::from_millis(100))
+        .body()
+        .await;
+    match res {
+        Err(PayloadError::Io(e)) => assert_eq!(e.kind(), std::io::ErrorKind::TimedOut),
+        _ => panic!("Response error type is not matched"),
+    }
+
+    let res = client
+        .get(srv.url("/"))
+        .send()
+        .await
+        .unwrap()
+        .timeout(Duration::from_millis(100))
+        .json::<HashMap<String, String>>()
+        .await;
+    match res {
+        Err(JsonPayloadError::Payload(PayloadError::Io(e))) => {
+            assert_eq!(e.kind(), std::io::ErrorKind::TimedOut)
+        }
+        _ => panic!("Response error type is not matched"),
+    }
+}
+
 #[actix_rt::test]
 async fn test_connection_reuse() {
     let num = Arc::new(AtomicUsize::new(0));
@@ -292,7 +367,7 @@ async fn test_connection_wait_queue() {
     .await;
 
     let client = awc::Client::builder()
-        .connector(awc::Connector::new().limit(1).finish())
+        .connector(awc::Connector::new().limit(1))
         .finish();
 
     // req 1
@@ -341,7 +416,7 @@ async fn test_connection_wait_queue_force_close() {
     .await;
 
     let client = awc::Client::builder()
-        .connector(awc::Connector::new().limit(1).finish())
+        .connector(awc::Connector::new().limit(1))
         .finish();
 
     // req 1
@@ -438,7 +513,7 @@ async fn test_client_gzip_encoding() {
             let data = e.finish().unwrap();
 
             HttpResponse::Ok()
-                .header("content-encoding", "gzip")
+                .insert_header(("content-encoding", "gzip"))
                 .body(data)
         })))
     });
@@ -461,7 +536,7 @@ async fn test_client_gzip_encoding_large() {
             let data = e.finish().unwrap();
 
             HttpResponse::Ok()
-                .header("content-encoding", "gzip")
+                .insert_header(("content-encoding", "gzip"))
                 .body(data)
         })))
     });
@@ -480,6 +555,7 @@ async fn test_client_gzip_encoding_large_random() {
     let data = rand::thread_rng()
         .sample_iter(&rand::distributions::Alphanumeric)
         .take(100_000)
+        .map(char::from)
         .collect::<String>();
 
     let srv = test::start(|| {
@@ -488,7 +564,7 @@ async fn test_client_gzip_encoding_large_random() {
             e.write_all(&data).unwrap();
             let data = e.finish().unwrap();
             HttpResponse::Ok()
-                .header("content-encoding", "gzip")
+                .insert_header(("content-encoding", "gzip"))
                 .body(data)
         })))
     });
@@ -510,7 +586,7 @@ async fn test_client_brotli_encoding() {
             e.write_all(&data).unwrap();
             let data = e.finish().unwrap();
             HttpResponse::Ok()
-                .header("content-encoding", "br")
+                .insert_header(("content-encoding", "br"))
                 .body(data)
         })))
     });
@@ -529,6 +605,7 @@ async fn test_client_brotli_encoding_large_random() {
     let data = rand::thread_rng()
         .sample_iter(&rand::distributions::Alphanumeric)
         .take(70_000)
+        .map(char::from)
         .collect::<String>();
 
     let srv = test::start(|| {
@@ -537,7 +614,7 @@ async fn test_client_brotli_encoding_large_random() {
             e.write_all(&data).unwrap();
             let data = e.finish().unwrap();
             HttpResponse::Ok()
-                .header("content-encoding", "br")
+                .insert_header(("content-encoding", "br"))
                 .body(data)
         })))
     });
@@ -552,113 +629,93 @@ async fn test_client_brotli_encoding_large_random() {
     assert_eq!(bytes, Bytes::from(data));
 }
 
-// #[actix_rt::test]
-// async fn test_client_deflate_encoding() {
-//     let srv = test::TestServer::start(|app| {
-//         app.handler(|req: &HttpRequest| {
-//             req.body()
-//                 .and_then(|bytes: Bytes| {
-//                     Ok(HttpResponse::Ok()
-//                         .content_encoding(http::ContentEncoding::Br)
-//                         .body(bytes))
-//                 })
-//                 .responder()
-//         })
-//     });
+#[actix_rt::test]
+async fn test_client_deflate_encoding() {
+    let srv = test::start(|| {
+        App::new().default_service(web::to(|body: Bytes| {
+            HttpResponse::Ok()
+                .encoding(http::ContentEncoding::Br)
+                .body(body)
+        }))
+    });
 
-//     // client request
-//     let request = srv
-//         .post()
-//         .content_encoding(http::ContentEncoding::Deflate)
-//         .body(STR)
-//         .unwrap();
-//     let response = srv.execute(request.send()).unwrap();
-//     assert!(response.status().is_success());
+    let req = srv.post("/").send_body(STR);
 
-//     // read response
-//     let bytes = srv.execute(response.body()).unwrap();
-//     assert_eq!(bytes, Bytes::from_static(STR.as_ref()));
-// }
+    let mut res = req.await.unwrap();
+    assert_eq!(res.status(), StatusCode::OK);
 
-// #[actix_rt::test]
-// async fn test_client_deflate_encoding_large_random() {
-//     let data = rand::thread_rng()
-//         .sample_iter(&rand::distributions::Alphanumeric)
-//         .take(70_000)
-//         .collect::<String>();
+    let bytes = res.body().await.unwrap();
+    assert_eq!(bytes, Bytes::from_static(STR.as_ref()));
+}
 
-//     let srv = test::TestServer::start(|app| {
-//         app.handler(|req: &HttpRequest| {
-//             req.body()
-//                 .and_then(|bytes: Bytes| {
-//                     Ok(HttpResponse::Ok()
-//                         .content_encoding(http::ContentEncoding::Br)
-//                         .body(bytes))
-//                 })
-//                 .responder()
-//         })
-//     });
+#[actix_rt::test]
+async fn test_client_deflate_encoding_large_random() {
+    let data = rand::thread_rng()
+        .sample_iter(rand::distributions::Alphanumeric)
+        .map(char::from)
+        .take(70_000)
+        .collect::<String>();
 
-//     // client request
-//     let request = srv
-//         .post()
-//         .content_encoding(http::ContentEncoding::Deflate)
-//         .body(data.clone())
-//         .unwrap();
-//     let response = srv.execute(request.send()).unwrap();
-//     assert!(response.status().is_success());
+    let srv = test::start(|| {
+        App::new().default_service(web::to(|body: Bytes| {
+            HttpResponse::Ok()
+                .encoding(http::ContentEncoding::Br)
+                .body(body)
+        }))
+    });
 
-//     // read response
-//     let bytes = srv.execute(response.body()).unwrap();
-//     assert_eq!(bytes, Bytes::from(data));
-// }
+    let req = srv.post("/").send_body(data.clone());
 
-// #[actix_rt::test]
-// async fn test_client_streaming_explicit() {
-//     let srv = test::TestServer::start(|app| {
-//         app.handler(|req: &HttpRequest| {
-//             req.body()
-//                 .map_err(Error::from)
-//                 .and_then(|body| {
-//                     Ok(HttpResponse::Ok()
-//                         .chunked()
-//                         .content_encoding(http::ContentEncoding::Identity)
-//                         .body(body))
-//                 })
-//                 .responder()
-//         })
-//     });
+    let mut res = req.await.unwrap();
+    let bytes = res.body().await.unwrap();
 
-//     let body = once(Ok(Bytes::from_static(STR.as_ref())));
+    assert_eq!(res.status(), StatusCode::OK);
+    assert_eq!(bytes, Bytes::from(data));
+}
 
-//     let request = srv.get("/").body(Body::Streaming(Box::new(body))).unwrap();
-//     let response = srv.execute(request.send()).unwrap();
-//     assert!(response.status().is_success());
+#[actix_rt::test]
+async fn test_client_streaming_explicit() {
+    let srv = test::start(|| {
+        App::new().default_service(web::to(|body: web::Payload| {
+            HttpResponse::Ok()
+                .encoding(http::ContentEncoding::Identity)
+                .streaming(body)
+        }))
+    });
 
-//     // read response
-//     let bytes = srv.execute(response.body()).unwrap();
-//     assert_eq!(bytes, Bytes::from_static(STR.as_ref()));
-// }
+    let body =
+        stream::once(async { Ok::<_, actix_http::Error>(Bytes::from_static(STR.as_bytes())) });
+    let req = srv.post("/").send_stream(Box::pin(body));
 
-// #[actix_rt::test]
-// async fn test_body_streaming_implicit() {
-//     let srv = test::TestServer::start(|app| {
-//         app.handler(|_| {
-//             let body = once(Ok(Bytes::from_static(STR.as_ref())));
-//             HttpResponse::Ok()
-//                 .content_encoding(http::ContentEncoding::Gzip)
-//                 .body(Body::Streaming(Box::new(body)))
-//         })
-//     });
+    let mut res = req.await.unwrap();
+    assert!(res.status().is_success());
 
-//     let request = srv.get("/").finish().unwrap();
-//     let response = srv.execute(request.send()).unwrap();
-//     assert!(response.status().is_success());
+    let bytes = res.body().await.unwrap();
+    assert_eq!(bytes, Bytes::from_static(STR.as_ref()));
+}
 
-//     // read response
-//     let bytes = srv.execute(response.body()).unwrap();
-//     assert_eq!(bytes, Bytes::from_static(STR.as_ref()));
-// }
+#[actix_rt::test]
+async fn test_body_streaming_implicit() {
+    let srv = test::start(|| {
+        App::new().default_service(web::to(|| {
+            let body = stream::once(async {
+                Ok::<_, actix_http::Error>(Bytes::from_static(STR.as_bytes()))
+            });
+
+            HttpResponse::Ok()
+                .encoding(http::ContentEncoding::Gzip)
+                .streaming(Box::pin(body))
+        }))
+    });
+
+    let req = srv.get("/").send();
+
+    let mut res = req.await.unwrap();
+    assert!(res.status().is_success());
+
+    let bytes = res.body().await.unwrap();
+    assert_eq!(bytes, Bytes::from_static(STR.as_ref()));
+}
 
 #[actix_rt::test]
 async fn test_client_cookie_handling() {
@@ -729,35 +786,35 @@ async fn test_client_cookie_handling() {
     assert_eq!(c2, cookie2);
 }
 
-// #[actix_rt::test]
-// fn client_read_until_eof() {
-//     let addr = test::TestServer::unused_addr();
+#[actix_rt::test]
+async fn client_unread_response() {
+    let addr = test::unused_addr();
 
-//     thread::spawn(move || {
-//         let lst = net::TcpListener::bind(addr).unwrap();
+    let lst = std::net::TcpListener::bind(addr).unwrap();
 
-//         for stream in lst.incoming() {
-//             let mut stream = stream.unwrap();
-//             let mut b = [0; 1000];
-//             let _ = stream.read(&mut b).unwrap();
-//             let _ = stream
-//                 .write_all(b"HTTP/1.1 200 OK\r\nconnection: close\r\n\r\nwelcome!");
-//         }
-//     });
+    std::thread::spawn(move || {
+        for stream in lst.incoming() {
+            let mut stream = stream.unwrap();
+            let mut b = [0; 1000];
+            let _ = stream.read(&mut b).unwrap();
+            let _ = stream.write_all(
+                b"HTTP/1.1 200 OK\r\n\
+                connection: close\r\n\
+                \r\n\
+                welcome!",
+            );
+        }
+    });
 
-//     let mut sys = actix::System::new("test");
+    // client request
+    let req = awc::Client::new().get(format!("http://{}/", addr).as_str());
+    let mut res = req.send().await.unwrap();
+    assert!(res.status().is_success());
 
-//     // client request
-//     let req = client::ClientRequest::get(format!("http://{}/", addr).as_str())
-//         .finish()
-//         .unwrap();
-//     let response = req.send().await.unwrap();
-//     assert!(response.status().is_success());
-
-//     // read response
-//     let bytes = response.body().await.unwrap();
-//     assert_eq!(bytes, Bytes::from_static(b"welcome!"));
-// }
+    // awc does not read all bytes unless content-length is specified
+    let bytes = res.body().await.unwrap();
+    assert_eq!(bytes, Bytes::from_static(b""));
+}
 
 #[actix_rt::test]
 async fn client_basic_auth() {
diff --git a/awc/tests/test_connector.rs b/awc/tests/test_connector.rs
index 888f7a900..632f68b72 100644
--- a/awc/tests/test_connector.rs
+++ b/awc/tests/test_connector.rs
@@ -1,29 +1,39 @@
 #![cfg(feature = "openssl")]
+
+extern crate tls_openssl as openssl;
+
 use actix_http::HttpService;
 use actix_http_test::test_server;
-use actix_service::{map_config, ServiceFactory};
+use actix_service::{map_config, ServiceFactoryExt};
 use actix_web::http::Version;
 use actix_web::{dev::AppConfig, web, App, HttpResponse};
-use open_ssl::ssl::{SslAcceptor, SslConnector, SslFiletype, SslMethod, SslVerifyMode};
+use openssl::{
+    pkey::PKey,
+    ssl::{SslAcceptor, SslConnector, SslMethod, SslVerifyMode},
+    x509::X509,
+};
+
+fn tls_config() -> SslAcceptor {
+    let cert = rcgen::generate_simple_self_signed(vec!["localhost".to_owned()]).unwrap();
+    let cert_file = cert.serialize_pem().unwrap();
+    let key_file = cert.serialize_private_key_pem();
+    let cert = X509::from_pem(cert_file.as_bytes()).unwrap();
+    let key = PKey::private_key_from_pem(key_file.as_bytes()).unwrap();
 
-fn ssl_acceptor() -> SslAcceptor {
-    // load ssl keys
     let mut builder = SslAcceptor::mozilla_intermediate(SslMethod::tls()).unwrap();
-    builder
-        .set_private_key_file("../tests/key.pem", SslFiletype::PEM)
-        .unwrap();
-    builder
-        .set_certificate_chain_file("../tests/cert.pem")
-        .unwrap();
+    builder.set_certificate(&cert).unwrap();
+    builder.set_private_key(&key).unwrap();
+
     builder.set_alpn_select_callback(|_, protos| {
         const H2: &[u8] = b"\x02h2";
         if protos.windows(3).any(|window| window == H2) {
             Ok(b"h2")
         } else {
-            Err(open_ssl::ssl::AlpnError::NOACK)
+            Err(openssl::ssl::AlpnError::NOACK)
         }
     });
     builder.set_alpn_protos(b"\x02h2").unwrap();
+
     builder.build()
 }
 
@@ -35,7 +45,7 @@ async fn test_connection_window_size() {
                 App::new().service(web::resource("/").route(web::to(HttpResponse::Ok))),
                 |_| AppConfig::default(),
             ))
-            .openssl(ssl_acceptor())
+            .openssl(tls_config())
             .map_err(|_| ())
     })
     .await;
@@ -48,7 +58,7 @@ async fn test_connection_window_size() {
         .map_err(|e| log::error!("Can not set alpn protocol: {:?}", e));
 
     let client = awc::Client::builder()
-        .connector(awc::Connector::new().ssl(builder.build()).finish())
+        .connector(awc::Connector::new().ssl(builder.build()))
         .initial_window_size(100)
         .initial_connection_window_size(100)
         .finish();
diff --git a/awc/tests/test_rustls_client.rs b/awc/tests/test_rustls_client.rs
index 0df6b154c..464edfe89 100644
--- a/awc/tests/test_rustls_client.rs
+++ b/awc/tests/test_rustls_client.rs
@@ -1,57 +1,57 @@
 #![cfg(feature = "rustls")]
-use std::sync::atomic::{AtomicUsize, Ordering};
-use std::sync::Arc;
+
+extern crate tls_rustls as rustls;
+
+use std::{
+    io::BufReader,
+    sync::{
+        atomic::{AtomicUsize, Ordering},
+        Arc,
+    },
+};
 
 use actix_http::HttpService;
 use actix_http_test::test_server;
-use actix_service::{map_config, pipeline_factory, ServiceFactory};
-use actix_web::http::Version;
-use actix_web::{dev::AppConfig, web, App, HttpResponse};
+use actix_service::{map_config, pipeline_factory, ServiceFactoryExt};
+use actix_web::{dev::AppConfig, http::Version, web, App, HttpResponse};
 use futures_util::future::ok;
-use open_ssl::ssl::{SslAcceptor, SslFiletype, SslMethod, SslVerifyMode};
-use rust_tls::ClientConfig;
+use rustls::internal::pemfile::{certs, pkcs8_private_keys};
+use rustls::{ClientConfig, NoClientAuth, ServerConfig};
 
-#[allow(unused)]
-fn ssl_acceptor() -> SslAcceptor {
-    // load ssl keys
-    let mut builder = SslAcceptor::mozilla_intermediate(SslMethod::tls()).unwrap();
-    builder.set_verify_callback(SslVerifyMode::NONE, |_, _| true);
-    builder
-        .set_private_key_file("../tests/key.pem", SslFiletype::PEM)
-        .unwrap();
-    builder
-        .set_certificate_chain_file("../tests/cert.pem")
-        .unwrap();
-    builder.set_alpn_select_callback(|_, protos| {
-        const H2: &[u8] = b"\x02h2";
-        if protos.windows(3).any(|window| window == H2) {
-            Ok(b"h2")
-        } else {
-            Err(open_ssl::ssl::AlpnError::NOACK)
-        }
-    });
-    builder.set_alpn_protos(b"\x02h2").unwrap();
-    builder.build()
+fn tls_config() -> ServerConfig {
+    let cert = rcgen::generate_simple_self_signed(vec!["localhost".to_owned()]).unwrap();
+    let cert_file = cert.serialize_pem().unwrap();
+    let key_file = cert.serialize_private_key_pem();
+
+    let mut config = ServerConfig::new(NoClientAuth::new());
+    let cert_file = &mut BufReader::new(cert_file.as_bytes());
+    let key_file = &mut BufReader::new(key_file.as_bytes());
+
+    let cert_chain = certs(cert_file).unwrap();
+    let mut keys = pkcs8_private_keys(key_file).unwrap();
+    config.set_single_cert(cert_chain, keys.remove(0)).unwrap();
+
+    config
 }
 
 mod danger {
-    pub struct NoCertificateVerification {}
+    pub struct NoCertificateVerification;
 
-    impl rust_tls::ServerCertVerifier for NoCertificateVerification {
+    impl rustls::ServerCertVerifier for NoCertificateVerification {
         fn verify_server_cert(
             &self,
-            _roots: &rust_tls::RootCertStore,
-            _presented_certs: &[rust_tls::Certificate],
+            _roots: &rustls::RootCertStore,
+            _presented_certs: &[rustls::Certificate],
             _dns_name: webpki::DNSNameRef<'_>,
             _ocsp: &[u8],
-        ) -> Result<rust_tls::ServerCertVerified, rust_tls::TLSError> {
-            Ok(rust_tls::ServerCertVerified::assertion())
+        ) -> Result<rustls::ServerCertVerified, rustls::TLSError> {
+            Ok(rustls::ServerCertVerified::assertion())
         }
     }
 }
 
-// #[actix_rt::test]
-async fn _test_connection_reuse_h2() {
+#[actix_rt::test]
+async fn test_connection_reuse_h2() {
     let num = Arc::new(AtomicUsize::new(0));
     let num2 = num.clone();
 
@@ -64,26 +64,25 @@ async fn _test_connection_reuse_h2() {
         .and_then(
             HttpService::build()
                 .h2(map_config(
-                    App::new()
-                        .service(web::resource("/").route(web::to(HttpResponse::Ok))),
+                    App::new().service(web::resource("/").route(web::to(HttpResponse::Ok))),
                     |_| AppConfig::default(),
                 ))
-                .openssl(ssl_acceptor())
+                .rustls(tls_config())
                 .map_err(|_| ()),
         )
     })
     .await;
 
-    // disable ssl verification
+    // disable TLS verification
     let mut config = ClientConfig::new();
     let protos = vec![b"h2".to_vec(), b"http/1.1".to_vec()];
     config.set_protocols(&protos);
     config
         .dangerous()
-        .set_certificate_verifier(Arc::new(danger::NoCertificateVerification {}));
+        .set_certificate_verifier(Arc::new(danger::NoCertificateVerification));
 
     let client = awc::Client::builder()
-        .connector(awc::Connector::new().rustls(Arc::new(config)).finish())
+        .connector(awc::Connector::new().rustls(Arc::new(config)))
         .finish();
 
     // req 1
diff --git a/awc/tests/test_ssl_client.rs b/awc/tests/test_ssl_client.rs
index eced5f14b..3079aaf5e 100644
--- a/awc/tests/test_ssl_client.rs
+++ b/awc/tests/test_ssl_client.rs
@@ -1,33 +1,43 @@
 #![cfg(feature = "openssl")]
+
+extern crate tls_openssl as openssl;
+
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;
 
 use actix_http::HttpService;
 use actix_http_test::test_server;
-use actix_service::{map_config, pipeline_factory, ServiceFactory};
+use actix_service::{map_config, pipeline_factory, ServiceFactoryExt};
 use actix_web::http::Version;
 use actix_web::{dev::AppConfig, web, App, HttpResponse};
 use futures_util::future::ok;
-use open_ssl::ssl::{SslAcceptor, SslConnector, SslFiletype, SslMethod, SslVerifyMode};
+use openssl::{
+    pkey::PKey,
+    ssl::{SslAcceptor, SslConnector, SslMethod, SslVerifyMode},
+    x509::X509,
+};
+
+fn tls_config() -> SslAcceptor {
+    let cert = rcgen::generate_simple_self_signed(vec!["localhost".to_owned()]).unwrap();
+    let cert_file = cert.serialize_pem().unwrap();
+    let key_file = cert.serialize_private_key_pem();
+    let cert = X509::from_pem(cert_file.as_bytes()).unwrap();
+    let key = PKey::private_key_from_pem(key_file.as_bytes()).unwrap();
 
-fn ssl_acceptor() -> SslAcceptor {
-    // load ssl keys
     let mut builder = SslAcceptor::mozilla_intermediate(SslMethod::tls()).unwrap();
-    builder
-        .set_private_key_file("../tests/key.pem", SslFiletype::PEM)
-        .unwrap();
-    builder
-        .set_certificate_chain_file("../tests/cert.pem")
-        .unwrap();
+    builder.set_certificate(&cert).unwrap();
+    builder.set_private_key(&key).unwrap();
+
     builder.set_alpn_select_callback(|_, protos| {
         const H2: &[u8] = b"\x02h2";
         if protos.windows(3).any(|window| window == H2) {
             Ok(b"h2")
         } else {
-            Err(open_ssl::ssl::AlpnError::NOACK)
+            Err(openssl::ssl::AlpnError::NOACK)
         }
     });
     builder.set_alpn_protos(b"\x02h2").unwrap();
+
     builder.build()
 }
 
@@ -45,11 +55,10 @@ async fn test_connection_reuse_h2() {
         .and_then(
             HttpService::build()
                 .h2(map_config(
-                    App::new()
-                        .service(web::resource("/").route(web::to(HttpResponse::Ok))),
+                    App::new().service(web::resource("/").route(web::to(HttpResponse::Ok))),
                     |_| AppConfig::default(),
                 ))
-                .openssl(ssl_acceptor())
+                .openssl(tls_config())
                 .map_err(|_| ()),
         )
     })
@@ -63,7 +72,7 @@ async fn test_connection_reuse_h2() {
         .map_err(|e| log::error!("Can not set alpn protocol: {:?}", e));
 
     let client = awc::Client::builder()
-        .connector(awc::Connector::new().ssl(builder.build()).finish())
+        .connector(awc::Connector::new().ssl(builder.build()))
         .finish();
 
     // req 1
diff --git a/awc/tests/test_ws.rs b/awc/tests/test_ws.rs
index 1c1068668..1b3f780dc 100644
--- a/awc/tests/test_ws.rs
+++ b/awc/tests/test_ws.rs
@@ -11,7 +11,7 @@ async fn ws_service(req: ws::Frame) -> Result<ws::Message, io::Error> {
     match req {
         ws::Frame::Ping(msg) => Ok(ws::Message::Pong(msg)),
         ws::Frame::Text(text) => Ok(ws::Message::Text(
-            String::from_utf8(Vec::from(text.as_ref())).unwrap(),
+            String::from_utf8(Vec::from(text.as_ref())).unwrap().into(),
         )),
         ws::Frame::Binary(bin) => Ok(ws::Message::Binary(bin)),
         ws::Frame::Close(reason) => Ok(ws::Message::Close(reason)),
@@ -31,7 +31,7 @@ async fn test_simple() {
                         .send(h1::Message::Item((res.drop_body(), BodySize::None)))
                         .await?;
 
-                    // start websocket service
+                    // start WebSocket service
                     let framed = framed.replace_codec(ws::Codec::new());
                     ws::Dispatcher::with(framed, ws_service).await
                 }
@@ -43,10 +43,7 @@ async fn test_simple() {
 
     // client service
     let mut framed = srv.ws().await.unwrap();
-    framed
-        .send(ws::Message::Text("text".to_string()))
-        .await
-        .unwrap();
+    framed.send(ws::Message::Text("text".into())).await.unwrap();
     let item = framed.next().await.unwrap().unwrap();
     assert_eq!(item, ws::Frame::Text(Bytes::from_static(b"text")));
 
diff --git a/benches/responder.rs b/benches/responder.rs
new file mode 100644
index 000000000..8cfdbd3ea
--- /dev/null
+++ b/benches/responder.rs
@@ -0,0 +1,113 @@
+use std::future::Future;
+use std::time::Instant;
+
+use actix_http::Response;
+use actix_web::http::StatusCode;
+use actix_web::test::TestRequest;
+use actix_web::{error, Error, HttpRequest, HttpResponse, Responder};
+use criterion::{criterion_group, criterion_main, Criterion};
+use futures_util::future::{ready, Either, Ready};
+
+// responder simulate the old responder trait.
+trait FutureResponder {
+    type Error;
+    type Future: Future<Output = Result<HttpResponse, Self::Error>>;
+
+    fn future_respond_to(self, req: &HttpRequest) -> Self::Future;
+}
+
+// a simple option responder type.
+struct OptionResponder<T>(Option<T>);
+
+// a simple wrapper type around string
+struct StringResponder(String);
+
+impl FutureResponder for StringResponder {
+    type Error = Error;
+    type Future = Ready<Result<Response, Self::Error>>;
+
+    fn future_respond_to(self, _: &HttpRequest) -> Self::Future {
+        // this is default builder for string response in both new and old responder trait.
+        ready(Ok(Response::build(StatusCode::OK)
+            .content_type("text/plain; charset=utf-8")
+            .body(self.0)))
+    }
+}
+
+impl<T> FutureResponder for OptionResponder<T>
+where
+    T: FutureResponder,
+    T::Future: Future<Output = Result<Response, Error>>,
+{
+    type Error = Error;
+    type Future = Either<T::Future, Ready<Result<HttpResponse, Self::Error>>>;
+
+    fn future_respond_to(self, req: &HttpRequest) -> Self::Future {
+        match self.0 {
+            Some(t) => Either::Left(t.future_respond_to(req)),
+            None => Either::Right(ready(Err(error::ErrorInternalServerError("err")))),
+        }
+    }
+}
+
+impl Responder for StringResponder {
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        Response::build(StatusCode::OK)
+            .content_type("text/plain; charset=utf-8")
+            .body(self.0)
+    }
+}
+
+impl<T: Responder> Responder for OptionResponder<T> {
+    fn respond_to(self, req: &HttpRequest) -> HttpResponse {
+        match self.0 {
+            Some(t) => t.respond_to(req),
+            None => Response::from_error(error::ErrorInternalServerError("err")),
+        }
+    }
+}
+
+fn future_responder(c: &mut Criterion) {
+    let rt = actix_rt::System::new();
+    let req = TestRequest::default().to_http_request();
+
+    c.bench_function("future_responder", move |b| {
+        b.iter_custom(|_| {
+            let futs = (0..100_000).map(|_| async {
+                StringResponder(String::from("Hello World!!"))
+                    .future_respond_to(&req)
+                    .await
+            });
+
+            let futs = futures_util::future::join_all(futs);
+
+            let start = Instant::now();
+
+            let _res = rt.block_on(async { futs.await });
+
+            start.elapsed()
+        })
+    });
+}
+
+fn responder(c: &mut Criterion) {
+    let rt = actix_rt::System::new();
+    let req = TestRequest::default().to_http_request();
+    c.bench_function("responder", move |b| {
+        b.iter_custom(|_| {
+            let responders =
+                (0..100_000).map(|_| StringResponder(String::from("Hello World!!")));
+
+            let start = Instant::now();
+            let _res = rt.block_on(async {
+                // don't need runtime block on but to be fair.
+                responders.map(|r| r.respond_to(&req)).collect::<Vec<_>>()
+            });
+
+            start.elapsed()
+        })
+    });
+}
+
+criterion_group!(responder_bench, future_responder, responder);
+criterion_main!(responder_bench);
diff --git a/benches/server.rs b/benches/server.rs
index 041d0fa57..9dd540a73 100644
--- a/benches/server.rs
+++ b/benches/server.rs
@@ -29,34 +29,38 @@ const STR: &str = "Hello World Hello World Hello World Hello World Hello World \
 fn bench_async_burst(c: &mut Criterion) {
     // We are using System here, since Runtime requires preinitialized tokio
     // Maybe add to actix_rt docs
-    let mut rt = actix_rt::System::new("test");
+    let rt = actix_rt::System::new();
 
-    let srv = test::start(|| {
-        App::new()
-            .service(web::resource("/").route(web::to(|| HttpResponse::Ok().body(STR))))
+    let srv = rt.block_on(async {
+        test::start(|| {
+            App::new()
+                .service(web::resource("/").route(web::to(|| HttpResponse::Ok().body(STR))))
+        })
     });
 
     let url = srv.url("/");
 
     c.bench_function("get_body_async_burst", move |b| {
         b.iter_custom(|iters| {
-            let client = Client::new().get(url.clone()).freeze().unwrap();
+            rt.block_on(async {
+                let client = Client::new().get(url.clone()).freeze().unwrap();
+
+                let start = std::time::Instant::now();
+                // benchmark body
 
-            let start = std::time::Instant::now();
-            // benchmark body
-            let resps = rt.block_on(async move {
                 let burst = (0..iters).map(|_| client.send());
-                join_all(burst).await
-            });
-            let elapsed = start.elapsed();
+                let resps = join_all(burst).await;
 
-            // if there are failed requests that might be an issue
-            let failed = resps.iter().filter(|r| r.is_err()).count();
-            if failed > 0 {
-                eprintln!("failed {} requests (might be bench timeout)", failed);
-            };
+                let elapsed = start.elapsed();
 
-            elapsed
+                // if there are failed requests that might be an issue
+                let failed = resps.iter().filter(|r| r.is_err()).count();
+                if failed > 0 {
+                    eprintln!("failed {} requests (might be bench timeout)", failed);
+                };
+
+                elapsed
+            })
         })
     });
 }
diff --git a/benches/service.rs b/benches/service.rs
index 8adbc8a0c..0d3264857 100644
--- a/benches/service.rs
+++ b/benches/service.rs
@@ -23,10 +23,9 @@ use actix_web::test::{init_service, ok_service, TestRequest};
 /// async_service_direct    time:   [1.0908 us 1.1656 us 1.2613 us]
 pub fn bench_async_service<S>(c: &mut Criterion, srv: S, name: &str)
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse, Error = Error>
-        + 'static,
+    S: Service<ServiceRequest, Response = ServiceResponse, Error = Error> + 'static,
 {
-    let mut rt = actix_rt::System::new("test");
+    let rt = actix_rt::System::new();
     let srv = Rc::new(RefCell::new(srv));
 
     let req = TestRequest::default().to_srv_request();
@@ -41,14 +40,15 @@ where
         b.iter_custom(|iters| {
             let srv = srv.clone();
             // exclude request generation, it appears it takes significant time vs call (3us vs 1us)
-            let reqs: Vec<_> = (0..iters)
+            let futs = (0..iters)
                 .map(|_| TestRequest::default().to_srv_request())
-                .collect();
+                .map(|req| srv.borrow_mut().call(req));
+
             let start = std::time::Instant::now();
             // benchmark body
             rt.block_on(async move {
-                for req in reqs {
-                    srv.borrow_mut().call(req).await.unwrap();
+                for fut in futs {
+                    fut.await.unwrap();
                 }
             });
             let elapsed = start.elapsed();
@@ -67,7 +67,7 @@ async fn index(req: ServiceRequest) -> Result<ServiceResponse, Error> {
 // Sample results on MacBook Pro '14
 // time:   [2.0724 us 2.1345 us 2.2074 us]
 fn async_web_service(c: &mut Criterion) {
-    let mut rt = actix_rt::System::new("test");
+    let rt = actix_rt::System::new();
     let srv = Rc::new(RefCell::new(rt.block_on(init_service(
         App::new().service(web::service("/").finish(index)),
     ))));
@@ -83,13 +83,14 @@ fn async_web_service(c: &mut Criterion) {
     c.bench_function("async_web_service_direct", move |b| {
         b.iter_custom(|iters| {
             let srv = srv.clone();
-            let reqs = (0..iters).map(|_| TestRequest::get().uri("/").to_request());
-
+            let futs = (0..iters)
+                .map(|_| TestRequest::get().uri("/").to_request())
+                .map(|req| srv.borrow_mut().call(req));
             let start = std::time::Instant::now();
             // benchmark body
             rt.block_on(async move {
-                for req in reqs {
-                    srv.borrow_mut().call(req).await.unwrap();
+                for fut in futs {
+                    fut.await.unwrap();
                 }
             });
             let elapsed = start.elapsed();
diff --git a/codecov.yml b/codecov.yml
index 90cdfab47..e6bc40203 100644
--- a/codecov.yml
+++ b/codecov.yml
@@ -1,4 +1,15 @@
-ignore: # ignore codecoverage on following paths
+comment: false
+
+coverage:
+  status:
+    project:
+      default:
+        threshold: 10% # make CI green
+    patch:
+      default:
+        threshold: 10% # make CI green
+
+ignore: # ignore code coverage on following paths
   - "**/tests"
   - "test-server"
   - "**/benches"
diff --git a/docs/graphs/net-only.dot b/docs/graphs/net-only.dot
index 0eebf2a6f..9488f3fe7 100644
--- a/docs/graphs/net-only.dot
+++ b/docs/graphs/net-only.dot
@@ -2,12 +2,10 @@ digraph {
     subgraph cluster_net {
         label="actix/actix-net";
         "actix-codec"
-        "actix-connect"
         "actix-macros"
         "actix-rt"
         "actix-server"
         "actix-service"
-        "actix-testing"
         "actix-threadpool"
         "actix-tls"
         "actix-tracing"
@@ -17,9 +15,7 @@ digraph {
 
     "actix-utils" -> { "actix-service" "actix-rt" "actix-codec" }
     "actix-tracing" -> { "actix-service" }
-    "actix-tls" -> { "actix-service" "actix-codec" "actix-utils" }
-    "actix-testing" -> { "actix-rt" "actix-macros" "actix-server" "actix-service" }
+    "actix-tls" -> { "actix-service" "actix-codec" "actix-utils" "actix-rt" }
     "actix-server" -> { "actix-service" "actix-rt" "actix-codec" "actix-utils" }
     "actix-rt" -> { "actix-macros" "actix-threadpool" }
-    "actix-connect" -> { "actix-service" "actix-codec" "actix-utils" "actix-rt" }
 }
diff --git a/docs/graphs/web-focus.dot b/docs/graphs/web-focus.dot
index 7abd51268..ec0f7a946 100644
--- a/docs/graphs/web-focus.dot
+++ b/docs/graphs/web-focus.dot
@@ -1,6 +1,7 @@
 digraph {
     subgraph cluster_web {
         label="actix/actix-web"
+
         "awc"
         "actix-web"
         "actix-files"
@@ -8,23 +9,27 @@ digraph {
         "actix-multipart"
         "actix-web-actors"
         "actix-web-codegen"
+        "actix-http-test"
     }
 
-    "actix-web" -> { "actix-codec" "actix-service" "actix-utils" "actix-router" "actix-rt" "actix-server" "actix-testing" "actix-macros" "actix-threadpool" "actix-tls" "actix-web-codegen" "actix-http" "awc" }
+    "actix-web" -> { "actix-codec" "actix-service" "actix-utils" "actix-router" "actix-rt" "actix-server" "macros" "threadpool" "actix-tls" "actix-web-codegen" "actix-http" "awc" }
     "awc" -> { "actix-codec" "actix-service" "actix-http" "actix-rt" }
     "actix-web-actors" -> { "actix" "actix-web" "actix-http" "actix-codec" }
     "actix-multipart" -> { "actix-web" "actix-service" "actix-utils" }
-    "actix-http" -> { "actix-service" "actix-codec" "actix-connect" "actix-utils" "actix-rt" "actix-threadpool" }
-    "actix-http" -> { "actix" "actix-tls" }[color=blue] // optional
-    "actix-files" -> { "actix-web" "actix-http" }
+    "actix-http" -> { "actix-service" "actix-codec" "actix-tls" "actix-utils" "actix-rt" "threadpool" }
+    "actix-http" -> { "actix-tls" }[color=blue] // optional
+    "actix-files" -> { "actix-web" }
+    "actix-http-test" -> { "actix-service" "actix-codec" "actix-tls" "actix-utils" "actix-rt" "actix-server" "awc" }
 
     // net
 
     "actix-utils" -> { "actix-service" "actix-rt" "actix-codec" }
     "actix-tracing" -> { "actix-service" }
     "actix-tls" -> { "actix-service" "actix-codec" "actix-utils" }
-    "actix-testing" -> { "actix-rt" "actix-macros" "actix-server" "actix-service" }
     "actix-server" -> { "actix-service" "actix-rt" "actix-codec" "actix-utils" }
-    "actix-rt" -> { "actix-macros" "actix-threadpool" }
-    "actix-connect" -> { "actix-service" "actix-codec" "actix-utils" "actix-rt" }
+    "actix-rt" -> { "macros" "threadpool" }
+
+    // actix
+
+    "actix" -> { "actix-rt" }
 }
diff --git a/docs/graphs/web-only.dot b/docs/graphs/web-only.dot
index 6e41fdc27..6f8292a3a 100644
--- a/docs/graphs/web-only.dot
+++ b/docs/graphs/web-only.dot
@@ -8,12 +8,13 @@ digraph {
         "actix-multipart"
         "actix-web-actors"
         "actix-web-codegen"
+        "actix-http-test"
     }
 
-    "actix-web" -> {  "actix-web-codegen" "actix-http" "awc" }
+    "actix-web" -> { "actix-web-codegen" "actix-http" "awc" }
     "awc" -> { "actix-http" }
     "actix-web-actors" -> { "actix" "actix-web" "actix-http" }
     "actix-multipart" -> { "actix-web" }
-    "actix-http" -> { "actix" }[color=blue] // optional
-    "actix-files" -> { "actix-web" "actix-http" }
+    "actix-files" -> { "actix-web" }
+    "actix-http-test" -> { "awc" }
 }
diff --git a/examples/basic.rs b/examples/basic.rs
index 8b2bf2319..99eef3ee1 100644
--- a/examples/basic.rs
+++ b/examples/basic.rs
@@ -18,8 +18,7 @@ async fn no_params() -> &'static str {
 
 #[actix_web::main]
 async fn main() -> std::io::Result<()> {
-    std::env::set_var("RUST_LOG", "actix_server=info,actix_web=info");
-    env_logger::init();
+    env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
 
     HttpServer::new(|| {
         App::new()
@@ -30,12 +29,8 @@ async fn main() -> std::io::Result<()> {
             .service(no_params)
             .service(
                 web::resource("/resource2/index.html")
-                    .wrap(
-                        middleware::DefaultHeaders::new().header("X-Version-R2", "0.3"),
-                    )
-                    .default_service(
-                        web::route().to(|| HttpResponse::MethodNotAllowed()),
-                    )
+                    .wrap(middleware::DefaultHeaders::new().header("X-Version-R2", "0.3"))
+                    .default_service(web::route().to(|| HttpResponse::MethodNotAllowed()))
                     .route(web::get().to(index_async)),
             )
             .service(web::resource("/test1.html").to(|| async { "Test\r\n" }))
diff --git a/examples/client.rs b/examples/client.rs
index 15cf24fa8..b9574590d 100644
--- a/examples/client.rs
+++ b/examples/client.rs
@@ -10,7 +10,7 @@ async fn main() -> Result<(), Error> {
     // Create request builder, configure request and send
     let mut response = client
         .get("https://www.rust-lang.org/")
-        .header("User-Agent", "Actix-web")
+        .append_header(("User-Agent", "Actix-web"))
         .send()
         .await?;
 
diff --git a/examples/on_connect.rs b/examples/on_connect.rs
new file mode 100644
index 000000000..ba5a18f3f
--- /dev/null
+++ b/examples/on_connect.rs
@@ -0,0 +1,47 @@
+//! This example shows how to use `actix_web::HttpServer::on_connect` to access a lower-level socket
+//! properties and pass them to a handler through request-local data.
+//!
+//! For an example of extracting a client TLS certificate, see:
+//! <https://github.com/actix/examples/tree/HEAD/rustls-client-cert>
+
+use std::{any::Any, io, net::SocketAddr};
+
+use actix_web::{dev::Extensions, rt::net::TcpStream, web, App, HttpServer};
+
+#[derive(Debug, Clone)]
+struct ConnectionInfo {
+    bind: SocketAddr,
+    peer: SocketAddr,
+    ttl: Option<u32>,
+}
+
+async fn route_whoami(conn_info: web::ReqData<ConnectionInfo>) -> String {
+    format!(
+        "Here is some info about your connection:\n\n{:#?}",
+        conn_info
+    )
+}
+
+fn get_conn_info(connection: &dyn Any, data: &mut Extensions) {
+    if let Some(sock) = connection.downcast_ref::<TcpStream>() {
+        data.insert(ConnectionInfo {
+            bind: sock.local_addr().unwrap(),
+            peer: sock.peer_addr().unwrap(),
+            ttl: sock.ttl().ok(),
+        });
+    } else {
+        unreachable!("connection should only be plaintext since no TLS is set up");
+    }
+}
+
+#[actix_web::main]
+async fn main() -> io::Result<()> {
+    env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
+
+    HttpServer::new(|| App::new().default_service(web::to(route_whoami)))
+        .on_connect(get_conn_info)
+        .bind(("127.0.0.1", 8080))?
+        .workers(1)
+        .run()
+        .await
+}
diff --git a/examples/uds.rs b/examples/uds.rs
index e34fa5ac9..096781984 100644
--- a/examples/uds.rs
+++ b/examples/uds.rs
@@ -22,8 +22,7 @@ async fn no_params() -> &'static str {
 #[cfg(unix)]
 #[actix_web::main]
 async fn main() -> std::io::Result<()> {
-    std::env::set_var("RUST_LOG", "actix_server=info,actix_web=info");
-    env_logger::init();
+    env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
 
     HttpServer::new(|| {
         App::new()
@@ -34,12 +33,8 @@ async fn main() -> std::io::Result<()> {
             .service(no_params)
             .service(
                 web::resource("/resource2/index.html")
-                    .wrap(
-                        middleware::DefaultHeaders::new().header("X-Version-R2", "0.3"),
-                    )
-                    .default_service(
-                        web::route().to(|| HttpResponse::MethodNotAllowed()),
-                    )
+                    .wrap(middleware::DefaultHeaders::new().header("X-Version-R2", "0.3"))
+                    .default_service(web::route().to(|| HttpResponse::MethodNotAllowed()))
                     .route(web::get().to(index_async)),
             )
             .service(web::resource("/test1.html").to(|| async { "Test\r\n" }))
diff --git a/rust-toolchain b/rust-toolchain
deleted file mode 100644
index a50908ca3..000000000
--- a/rust-toolchain
+++ /dev/null
@@ -1 +0,0 @@
-1.42.0
diff --git a/rustfmt.toml b/rustfmt.toml
index 94bd11d51..973e002c0 100644
--- a/rustfmt.toml
+++ b/rustfmt.toml
@@ -1,2 +1,2 @@
-max_width = 89
+max_width = 96
 reorder_imports = true
diff --git a/src/app.rs b/src/app.rs
index fdedb0a75..7a26a3a89 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -5,10 +5,10 @@ use std::marker::PhantomData;
 use std::rc::Rc;
 
 use actix_http::body::{Body, MessageBody};
-use actix_http::Extensions;
+use actix_http::{Extensions, Request};
 use actix_service::boxed::{self, BoxServiceFactory};
 use actix_service::{
-    apply, apply_fn_factory, IntoServiceFactory, ServiceFactory, Transform,
+    apply, apply_fn_factory, IntoServiceFactory, ServiceFactory, ServiceFactoryExt, Transform,
 };
 use futures_util::future::FutureExt;
 
@@ -33,11 +33,10 @@ pub struct App<T, B> {
     services: Vec<Box<dyn AppServiceFactory>>,
     default: Option<Rc<HttpNewService>>,
     factory_ref: Rc<RefCell<Option<AppRoutingFactory>>>,
-    data: Vec<Box<dyn DataFactory>>,
     data_factories: Vec<FnDataFactory>,
     external: Vec<ResourceDef>,
     extensions: Extensions,
-    _t: PhantomData<B>,
+    _phantom: PhantomData<B>,
 }
 
 impl App<AppEntry, Body> {
@@ -47,14 +46,13 @@ impl App<AppEntry, Body> {
         let fref = Rc::new(RefCell::new(None));
         App {
             endpoint: AppEntry::new(fref.clone()),
-            data: Vec::new(),
             data_factories: Vec::new(),
             services: Vec::new(),
             default: None,
             factory_ref: fref,
             external: Vec::new(),
             extensions: Extensions::new(),
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
@@ -63,8 +61,8 @@ impl<T, B> App<T, B>
 where
     B: MessageBody,
     T: ServiceFactory<
+        ServiceRequest,
         Config = (),
-        Request = ServiceRequest,
         Response = ServiceResponse<B>,
         Error = Error,
         InitError = (),
@@ -73,7 +71,7 @@ where
     /// Set application data. Application data could be accessed
     /// by using `Data<T>` extractor where `T` is data type.
     ///
-    /// **Note**: http server accepts an application factory rather than
+    /// **Note**: HTTP server accepts an application factory rather than
     /// an application instance. Http server constructs an application
     /// instance for each thread, thus application data must be constructed
     /// multiple times. If you want to share data between different
@@ -100,9 +98,8 @@ where
     ///         web::resource("/index.html").route(
     ///             web::get().to(index)));
     /// ```
-    pub fn data<U: 'static>(mut self, data: U) -> Self {
-        self.data.push(Box::new(Data::new(data)));
-        self
+    pub fn data<U: 'static>(self, data: U) -> Self {
+        self.app_data(Data::new(data))
     }
 
     /// Set application data factory. This function is
@@ -156,8 +153,7 @@ where
     /// some of the resource's configuration could be moved to different module.
     ///
     /// ```rust
-    /// # extern crate actix_web;
-    /// use actix_web::{web, middleware, App, HttpResponse};
+    /// use actix_web::{web, App, HttpResponse};
     ///
     /// // this function could be located in different module
     /// fn config(cfg: &mut web::ServiceConfig) {
@@ -167,12 +163,9 @@ where
     ///     );
     /// }
     ///
-    /// fn main() {
-    ///     let app = App::new()
-    ///         .wrap(middleware::Logger::default())
-    ///         .configure(config)  // <- register resources
-    ///         .route("/index.html", web::get().to(|| HttpResponse::Ok()));
-    /// }
+    /// App::new()
+    ///     .configure(config)  // <- register resources
+    ///     .route("/index.html", web::get().to(|| HttpResponse::Ok()));
     /// ```
     pub fn configure<F>(mut self, f: F) -> Self
     where
@@ -180,9 +173,9 @@ where
     {
         let mut cfg = ServiceConfig::new();
         f(&mut cfg);
-        self.data.extend(cfg.data);
         self.services.extend(cfg.services);
         self.external.extend(cfg.external);
+        self.extensions.extend(cfg.app_data);
         self
     }
 
@@ -213,11 +206,11 @@ where
         )
     }
 
-    /// Register http service.
+    /// Register HTTP service.
     ///
     /// Http service is any type that implements `HttpServiceFactory` trait.
     ///
-    /// Actix web provides several services implementations:
+    /// Actix Web provides several services implementations:
     ///
     /// * *Resource* is an entry in resource table which corresponds to requested URL.
     /// * *Scope* is a set of resources with common root path.
@@ -267,10 +260,10 @@ where
     /// ```
     pub fn default_service<F, U>(mut self, f: F) -> Self
     where
-        F: IntoServiceFactory<U>,
+        F: IntoServiceFactory<U, ServiceRequest>,
         U: ServiceFactory<
+                ServiceRequest,
                 Config = (),
-                Request = ServiceRequest,
                 Response = ServiceResponse,
                 Error = Error,
             > + 'static,
@@ -352,8 +345,8 @@ where
         mw: M,
     ) -> App<
         impl ServiceFactory<
+            ServiceRequest,
             Config = (),
-            Request = ServiceRequest,
             Response = ServiceResponse<B1>,
             Error = Error,
             InitError = (),
@@ -363,7 +356,7 @@ where
     where
         M: Transform<
             T::Service,
-            Request = ServiceRequest,
+            ServiceRequest,
             Response = ServiceResponse<B1>,
             Error = Error,
             InitError = (),
@@ -372,14 +365,13 @@ where
     {
         App {
             endpoint: apply(mw, self.endpoint),
-            data: self.data,
             data_factories: self.data_factories,
             services: self.services,
             default: self.default,
             factory_ref: self.factory_ref,
             external: self.external,
             extensions: self.extensions,
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 
@@ -419,8 +411,8 @@ where
         mw: F,
     ) -> App<
         impl ServiceFactory<
+            ServiceRequest,
             Config = (),
-            Request = ServiceRequest,
             Response = ServiceResponse<B1>,
             Error = Error,
             InitError = (),
@@ -429,38 +421,37 @@ where
     >
     where
         B1: MessageBody,
-        F: FnMut(ServiceRequest, &mut T::Service) -> R + Clone,
+        F: Fn(ServiceRequest, &T::Service) -> R + Clone,
         R: Future<Output = Result<ServiceResponse<B1>, Error>>,
     {
         App {
             endpoint: apply_fn_factory(self.endpoint, mw),
-            data: self.data,
             data_factories: self.data_factories,
             services: self.services,
             default: self.default,
             factory_ref: self.factory_ref,
             external: self.external,
             extensions: self.extensions,
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
 
-impl<T, B> IntoServiceFactory<AppInit<T, B>> for App<T, B>
+impl<T, B> IntoServiceFactory<AppInit<T, B>, Request> for App<T, B>
 where
     B: MessageBody,
     T: ServiceFactory<
+        ServiceRequest,
         Config = (),
-        Request = ServiceRequest,
         Response = ServiceResponse<B>,
         Error = Error,
         InitError = (),
     >,
+    T::Future: 'static,
 {
     fn into_factory(self) -> AppInit<T, B> {
         AppInit {
-            data: Rc::new(self.data),
-            data_factories: Rc::new(self.data_factories),
+            async_data_factories: self.data_factories.into_boxed_slice().into(),
             endpoint: self.endpoint,
             services: Rc::new(RefCell::new(self.services)),
             external: RefCell::new(self.external),
@@ -481,17 +472,13 @@ mod tests {
     use crate::http::{header, HeaderValue, Method, StatusCode};
     use crate::middleware::DefaultHeaders;
     use crate::service::ServiceRequest;
-    use crate::test::{
-        call_service, init_service, read_body, try_init_service, TestRequest,
-    };
+    use crate::test::{call_service, init_service, read_body, try_init_service, TestRequest};
     use crate::{web, HttpRequest, HttpResponse};
 
     #[actix_rt::test]
     async fn test_default_resource() {
-        let mut srv = init_service(
-            App::new().service(web::resource("/test").to(HttpResponse::Ok)),
-        )
-        .await;
+        let srv =
+            init_service(App::new().service(web::resource("/test").to(HttpResponse::Ok))).await;
         let req = TestRequest::with_uri("/test").to_request();
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::OK);
@@ -500,7 +487,7 @@ mod tests {
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::NOT_FOUND);
 
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .service(web::resource("/test").to(HttpResponse::Ok))
                 .service(
@@ -533,20 +520,22 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_data_factory() {
-        let mut srv =
-            init_service(App::new().data_factory(|| ok::<_, ()>(10usize)).service(
-                web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok()),
-            ))
-            .await;
+        let srv = init_service(
+            App::new()
+                .data_factory(|| ok::<_, ()>(10usize))
+                .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok())),
+        )
+        .await;
         let req = TestRequest::default().to_request();
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::OK);
 
-        let mut srv =
-            init_service(App::new().data_factory(|| ok::<_, ()>(10u32)).service(
-                web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok()),
-            ))
-            .await;
+        let srv = init_service(
+            App::new()
+                .data_factory(|| ok::<_, ()>(10u32))
+                .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok())),
+        )
+        .await;
         let req = TestRequest::default().to_request();
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR);
@@ -554,23 +543,24 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_data_factory_errors() {
-        let srv =
-            try_init_service(App::new().data_factory(|| err::<u32, _>(())).service(
-                web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok()),
-            ))
-            .await;
+        let srv = try_init_service(
+            App::new()
+                .data_factory(|| err::<u32, _>(()))
+                .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok())),
+        )
+        .await;
 
         assert!(srv.is_err());
     }
 
     #[actix_rt::test]
     async fn test_extension() {
-        let mut srv = init_service(App::new().app_data(10usize).service(
-            web::resource("/").to(|req: HttpRequest| {
+        let srv = init_service(App::new().app_data(10usize).service(web::resource("/").to(
+            |req: HttpRequest| {
                 assert_eq!(*req.app_data::<usize>().unwrap(), 10);
                 HttpResponse::Ok()
-            }),
-        ))
+            },
+        )))
         .await;
         let req = TestRequest::default().to_request();
         let resp = srv.call(req).await.unwrap();
@@ -579,7 +569,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_wrap() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .wrap(
                     DefaultHeaders::new()
@@ -589,7 +579,7 @@ mod tests {
         )
         .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
@@ -599,7 +589,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_router_wrap() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .route("/test", web::get().to(HttpResponse::Ok))
                 .wrap(
@@ -609,7 +599,7 @@ mod tests {
         )
         .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
@@ -619,16 +609,14 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_wrap_fn() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .wrap_fn(|req, srv| {
                     let fut = srv.call(req);
                     async move {
                         let mut res = fut.await?;
-                        res.headers_mut().insert(
-                            header::CONTENT_TYPE,
-                            HeaderValue::from_static("0001"),
-                        );
+                        res.headers_mut()
+                            .insert(header::CONTENT_TYPE, HeaderValue::from_static("0001"));
                         Ok(res)
                     }
                 })
@@ -636,7 +624,7 @@ mod tests {
         )
         .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
@@ -646,24 +634,22 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_router_wrap_fn() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .route("/test", web::get().to(HttpResponse::Ok))
                 .wrap_fn(|req, srv| {
                     let fut = srv.call(req);
                     async {
                         let mut res = fut.await?;
-                        res.headers_mut().insert(
-                            header::CONTENT_TYPE,
-                            HeaderValue::from_static("0001"),
-                        );
+                        res.headers_mut()
+                            .insert(header::CONTENT_TYPE, HeaderValue::from_static("0001"));
                         Ok(res)
                     }
                 }),
         )
         .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
@@ -673,21 +659,20 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_external_resource() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .external_resource("youtube", "https://youtube.com/watch/{video_id}")
                 .route(
                     "/test",
                     web::get().to(|req: HttpRequest| {
-                        HttpResponse::Ok().body(
-                            req.url_for("youtube", &["12345"]).unwrap().to_string(),
-                        )
+                        HttpResponse::Ok()
+                            .body(req.url_for("youtube", &["12345"]).unwrap().to_string())
                     }),
                 ),
         )
         .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         let body = read_body(resp).await;
         assert_eq!(body, Bytes::from_static(b"https://youtube.com/watch/12345"));
diff --git a/src/app_service.rs b/src/app_service.rs
index 98d8c8a8d..9b4ae3354 100644
--- a/src/app_service.rs
+++ b/src/app_service.rs
@@ -1,19 +1,16 @@
 use std::cell::RefCell;
-use std::future::Future;
-use std::marker::PhantomData;
-use std::pin::Pin;
 use std::rc::Rc;
-use std::task::{Context, Poll};
+use std::task::Poll;
 
 use actix_http::{Extensions, Request, Response};
-use actix_router::{Path, ResourceDef, ResourceInfo, Router, Url};
+use actix_router::{Path, ResourceDef, Router, Url};
 use actix_service::boxed::{self, BoxService, BoxServiceFactory};
 use actix_service::{fn_service, Service, ServiceFactory};
-use futures_util::future::{join_all, ok, FutureExt, LocalBoxFuture};
-use tinyvec::tiny_vec;
+use futures_core::future::LocalBoxFuture;
+use futures_util::future::join_all;
 
 use crate::config::{AppConfig, AppService};
-use crate::data::{DataFactory, FnDataFactory};
+use crate::data::FnDataFactory;
 use crate::error::Error;
 use crate::guard::Guard;
 use crate::request::{HttpRequest, HttpRequestPool};
@@ -23,15 +20,14 @@ use crate::service::{AppServiceFactory, ServiceRequest, ServiceResponse};
 type Guards = Vec<Box<dyn Guard>>;
 type HttpService = BoxService<ServiceRequest, ServiceResponse, Error>;
 type HttpNewService = BoxServiceFactory<(), ServiceRequest, ServiceResponse, Error, ()>;
-type BoxResponse = LocalBoxFuture<'static, Result<ServiceResponse, Error>>;
 
 /// Service factory to convert `Request` to a `ServiceRequest<S>`.
 /// It also executes data factories.
 pub struct AppInit<T, B>
 where
     T: ServiceFactory<
+        ServiceRequest,
         Config = (),
-        Request = ServiceRequest,
         Response = ServiceResponse<B>,
         Error = Error,
         InitError = (),
@@ -39,42 +35,42 @@ where
 {
     pub(crate) endpoint: T,
     pub(crate) extensions: RefCell<Option<Extensions>>,
-    pub(crate) data: Rc<Vec<Box<dyn DataFactory>>>,
-    pub(crate) data_factories: Rc<Vec<FnDataFactory>>,
+    pub(crate) async_data_factories: Rc<[FnDataFactory]>,
     pub(crate) services: Rc<RefCell<Vec<Box<dyn AppServiceFactory>>>>,
     pub(crate) default: Option<Rc<HttpNewService>>,
     pub(crate) factory_ref: Rc<RefCell<Option<AppRoutingFactory>>>,
     pub(crate) external: RefCell<Vec<ResourceDef>>,
 }
 
-impl<T, B> ServiceFactory for AppInit<T, B>
+impl<T, B> ServiceFactory<Request> for AppInit<T, B>
 where
     T: ServiceFactory<
+        ServiceRequest,
         Config = (),
-        Request = ServiceRequest,
         Response = ServiceResponse<B>,
         Error = Error,
         InitError = (),
     >,
+    T::Future: 'static,
 {
-    type Config = AppConfig;
-    type Request = Request;
     type Response = ServiceResponse<B>;
     type Error = T::Error;
-    type InitError = T::InitError;
+    type Config = AppConfig;
     type Service = AppInitService<T::Service, B>;
-    type Future = AppInitResult<T, B>;
+    type InitError = T::InitError;
+    type Future = LocalBoxFuture<'static, Result<Self::Service, Self::InitError>>;
 
     fn new_service(&self, config: AppConfig) -> Self::Future {
-        // update resource default service
+        // set AppService's default service to 404 NotFound
+        // if no user defined default service exists.
         let default = self.default.clone().unwrap_or_else(|| {
-            Rc::new(boxed::factory(fn_service(|req: ServiceRequest| {
-                ok(req.into_response(Response::NotFound().finish()))
+            Rc::new(boxed::factory(fn_service(|req: ServiceRequest| async {
+                Ok(req.into_response(Response::NotFound().finish()))
             })))
         });
 
         // App config
-        let mut config = AppService::new(config, default.clone(), self.data.clone());
+        let mut config = AppService::new(config, default.clone());
 
         // register services
         std::mem::take(&mut *self.services.borrow_mut())
@@ -85,18 +81,18 @@ where
 
         let (config, services) = config.into_services();
 
-        // complete pipeline creation
+        // complete pipeline creation.
         *self.factory_ref.borrow_mut() = Some(AppRoutingFactory {
             default,
-            services: Rc::new(
-                services
-                    .into_iter()
-                    .map(|(mut rdef, srv, guards, nested)| {
-                        rmap.add(&mut rdef, nested);
-                        (rdef, srv, RefCell::new(guards))
-                    })
-                    .collect(),
-            ),
+            services: services
+                .into_iter()
+                .map(|(mut rdef, srv, guards, nested)| {
+                    rmap.add(&mut rdef, nested);
+                    (rdef, srv, RefCell::new(guards))
+                })
+                .collect::<Vec<_>>()
+                .into_boxed_slice()
+                .into(),
         });
 
         // external resources
@@ -108,302 +104,190 @@ where
         let rmap = Rc::new(rmap);
         rmap.finish(rmap.clone());
 
-        // start all data factory futures
-        let factory_futs = join_all(self.data_factories.iter().map(|f| f()));
+        // construct all async data factory futures
+        let factory_futs = join_all(self.async_data_factories.iter().map(|f| f()));
 
-        AppInitResult {
-            endpoint: None,
-            endpoint_fut: self.endpoint.new_service(()),
-            data: self.data.clone(),
-            data_factories: None,
-            data_factories_fut: factory_futs.boxed_local(),
-            extensions: Some(
-                self.extensions
-                    .borrow_mut()
-                    .take()
-                    .unwrap_or_else(Extensions::new),
-            ),
-            config,
-            rmap,
-            _t: PhantomData,
-        }
+        // construct app service and middleware service factory future.
+        let endpoint_fut = self.endpoint.new_service(());
+
+        // take extensions or create new one as app data container.
+        let mut app_data = self
+            .extensions
+            .borrow_mut()
+            .take()
+            .unwrap_or_else(Extensions::new);
+
+        Box::pin(async move {
+            // async data factories
+            let async_data_factories = factory_futs
+                .await
+                .into_iter()
+                .collect::<Result<Vec<_>, _>>()
+                .map_err(|_| ())?;
+
+            // app service and middleware
+            let service = endpoint_fut.await?;
+
+            // populate app data container from (async) data factories.
+            async_data_factories.iter().for_each(|factory| {
+                factory.create(&mut app_data);
+            });
+
+            Ok(AppInitService {
+                service,
+                app_data: Rc::new(app_data),
+                app_state: AppInitServiceState::new(rmap, config),
+            })
+        })
     }
 }
 
-#[pin_project::pin_project]
-pub struct AppInitResult<T, B>
-where
-    T: ServiceFactory,
-{
-    #[pin]
-    endpoint_fut: T::Future,
-    // a Some signals completion of endpoint creation
-    endpoint: Option<T::Service>,
-
-    #[pin]
-    data_factories_fut: LocalBoxFuture<'static, Vec<Result<Box<dyn DataFactory>, ()>>>,
-    // a Some signals completion of factory futures
-    data_factories: Option<Vec<Box<dyn DataFactory>>>,
-
-    rmap: Rc<ResourceMap>,
-    config: AppConfig,
-    data: Rc<Vec<Box<dyn DataFactory>>>,
-    extensions: Option<Extensions>,
-
-    _t: PhantomData<B>,
-}
-
-impl<T, B> Future for AppInitResult<T, B>
-where
-    T: ServiceFactory<
-        Config = (),
-        Request = ServiceRequest,
-        Response = ServiceResponse<B>,
-        Error = Error,
-        InitError = (),
-    >,
-{
-    type Output = Result<AppInitService<T::Service, B>, ()>;
-
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.project();
-
-        // async data factories
-        if let Poll::Ready(factories) = this.data_factories_fut.poll(cx) {
-            let factories: Result<Vec<_>, ()> = factories.into_iter().collect();
-
-            if let Ok(factories) = factories {
-                this.data_factories.replace(factories);
-            } else {
-                return Poll::Ready(Err(()));
-            }
-        }
-
-        // app service and middleware
-        if this.endpoint.is_none() {
-            if let Poll::Ready(srv) = this.endpoint_fut.poll(cx)? {
-                *this.endpoint = Some(srv);
-            }
-        }
-
-        // not using if let so condition only needs shared ref
-        if this.endpoint.is_some() && this.data_factories.is_some() {
-            // create app data container
-            let mut data = this.extensions.take().unwrap();
-
-            for f in this.data.iter() {
-                f.create(&mut data);
-            }
-
-            for f in this.data_factories.take().unwrap().iter() {
-                f.create(&mut data);
-            }
-
-            return Poll::Ready(Ok(AppInitService {
-                service: this.endpoint.take().unwrap(),
-                rmap: this.rmap.clone(),
-                config: this.config.clone(),
-                data: Rc::new(data),
-                pool: HttpRequestPool::create(),
-            }));
-        }
-
-        Poll::Pending
-    }
-}
-
-/// Service to convert `Request` to a `ServiceRequest<S>`
+/// Service that takes a [`Request`] and delegates to a service that take a [`ServiceRequest`].
 pub struct AppInitService<T, B>
 where
-    T: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    T: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
 {
     service: T,
-    rmap: Rc<ResourceMap>,
-    config: AppConfig,
-    data: Rc<Extensions>,
-    pool: &'static HttpRequestPool,
+    app_data: Rc<Extensions>,
+    app_state: Rc<AppInitServiceState>,
 }
 
-impl<T, B> Service for AppInitService<T, B>
+/// A collection of [`AppInitService`] state that shared across `HttpRequest`s.
+pub(crate) struct AppInitServiceState {
+    rmap: Rc<ResourceMap>,
+    config: AppConfig,
+    pool: HttpRequestPool,
+}
+
+impl AppInitServiceState {
+    pub(crate) fn new(rmap: Rc<ResourceMap>, config: AppConfig) -> Rc<Self> {
+        Rc::new(AppInitServiceState {
+            rmap,
+            config,
+            // TODO: AppConfig can be used to pass user defined HttpRequestPool
+            // capacity.
+            pool: HttpRequestPool::default(),
+        })
+    }
+
+    #[inline]
+    pub(crate) fn rmap(&self) -> &ResourceMap {
+        &*self.rmap
+    }
+
+    #[inline]
+    pub(crate) fn config(&self) -> &AppConfig {
+        &self.config
+    }
+
+    #[inline]
+    pub(crate) fn pool(&self) -> &HttpRequestPool {
+        &self.pool
+    }
+}
+
+impl<T, B> Service<Request> for AppInitService<T, B>
 where
-    T: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    T: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
 {
-    type Request = Request;
     type Response = ServiceResponse<B>;
     type Error = T::Error;
     type Future = T::Future;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.service.poll_ready(cx)
-    }
+    actix_service::forward_ready!(service);
 
-    fn call(&mut self, req: Request) -> Self::Future {
+    fn call(&self, req: Request) -> Self::Future {
         let (head, payload) = req.into_parts();
 
-        let req = if let Some(mut req) = self.pool.get_request() {
-            let inner = Rc::get_mut(&mut req.0).unwrap();
+        let req = if let Some(mut req) = self.app_state.pool().pop() {
+            let inner = Rc::get_mut(&mut req.inner).unwrap();
             inner.path.get_mut().update(&head.uri);
             inner.path.reset();
             inner.head = head;
-            inner.payload = payload;
-            inner.app_data = tiny_vec![self.data.clone()];
             req
         } else {
             HttpRequest::new(
                 Path::new(Url::new(head.uri.clone())),
                 head,
-                payload,
-                self.rmap.clone(),
-                self.config.clone(),
-                self.data.clone(),
-                self.pool,
+                self.app_state.clone(),
+                self.app_data.clone(),
             )
         };
-        self.service.call(ServiceRequest::new(req))
+        self.service.call(ServiceRequest::new(req, payload))
     }
 }
 
 impl<T, B> Drop for AppInitService<T, B>
 where
-    T: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    T: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
 {
     fn drop(&mut self) {
-        self.pool.clear();
+        self.app_state.pool().clear();
     }
 }
 
 pub struct AppRoutingFactory {
-    services: Rc<Vec<(ResourceDef, HttpNewService, RefCell<Option<Guards>>)>>,
+    services: Rc<[(ResourceDef, HttpNewService, RefCell<Option<Guards>>)]>,
     default: Rc<HttpNewService>,
 }
 
-impl ServiceFactory for AppRoutingFactory {
-    type Config = ();
-    type Request = ServiceRequest;
+impl ServiceFactory<ServiceRequest> for AppRoutingFactory {
     type Response = ServiceResponse;
     type Error = Error;
-    type InitError = ();
+    type Config = ();
     type Service = AppRouting;
-    type Future = AppRoutingFactoryResponse;
+    type InitError = ();
+    type Future = LocalBoxFuture<'static, Result<Self::Service, Self::InitError>>;
 
     fn new_service(&self, _: ()) -> Self::Future {
-        AppRoutingFactoryResponse {
-            fut: self
-                .services
-                .iter()
-                .map(|(path, service, guards)| {
-                    CreateAppRoutingItem::Future(
-                        Some(path.clone()),
-                        guards.borrow_mut().take(),
-                        service.new_service(()).boxed_local(),
-                    )
-                })
-                .collect(),
-            default: None,
-            default_fut: Some(self.default.new_service(())),
-        }
-    }
-}
-
-type HttpServiceFut = LocalBoxFuture<'static, Result<HttpService, ()>>;
-
-/// Create app service
-#[doc(hidden)]
-pub struct AppRoutingFactoryResponse {
-    fut: Vec<CreateAppRoutingItem>,
-    default: Option<HttpService>,
-    default_fut: Option<LocalBoxFuture<'static, Result<HttpService, ()>>>,
-}
-
-enum CreateAppRoutingItem {
-    Future(Option<ResourceDef>, Option<Guards>, HttpServiceFut),
-    Service(ResourceDef, Option<Guards>, HttpService),
-}
-
-impl Future for AppRoutingFactoryResponse {
-    type Output = Result<AppRouting, ()>;
-
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let mut done = true;
-
-        if let Some(ref mut fut) = self.default_fut {
-            match Pin::new(fut).poll(cx)? {
-                Poll::Ready(default) => self.default = Some(default),
-                Poll::Pending => done = false,
+        // construct all services factory future with it's resource def and guards.
+        let factory_fut = join_all(self.services.iter().map(|(path, factory, guards)| {
+            let path = path.clone();
+            let guards = guards.borrow_mut().take();
+            let factory_fut = factory.new_service(());
+            async move {
+                let service = factory_fut.await?;
+                Ok((path, guards, service))
             }
-        }
+        }));
 
-        // poll http services
-        for item in &mut self.fut {
-            let res = match item {
-                CreateAppRoutingItem::Future(
-                    ref mut path,
-                    ref mut guards,
-                    ref mut fut,
-                ) => match Pin::new(fut).poll(cx) {
-                    Poll::Ready(Ok(service)) => {
-                        Some((path.take().unwrap(), guards.take(), service))
-                    }
-                    Poll::Ready(Err(_)) => return Poll::Ready(Err(())),
-                    Poll::Pending => {
-                        done = false;
-                        None
-                    }
-                },
-                CreateAppRoutingItem::Service(_, _, _) => continue,
-            };
+        // construct default service factory future
+        let default_fut = self.default.new_service(());
 
-            if let Some((path, guards, service)) = res {
-                *item = CreateAppRoutingItem::Service(path, guards, service);
-            }
-        }
+        Box::pin(async move {
+            let default = default_fut.await?;
 
-        if done {
-            let router = self
-                .fut
+            // build router from the factory future result.
+            let router = factory_fut
+                .await
+                .into_iter()
+                .collect::<Result<Vec<_>, _>>()?
                 .drain(..)
-                .fold(Router::build(), |mut router, item| {
-                    match item {
-                        CreateAppRoutingItem::Service(path, guards, service) => {
-                            router.rdef(path, service).2 = guards;
-                        }
-                        CreateAppRoutingItem::Future(_, _, _) => unreachable!(),
-                    }
+                .fold(Router::build(), |mut router, (path, guards, service)| {
+                    router.rdef(path, service).2 = guards;
                     router
-                });
-            Poll::Ready(Ok(AppRouting {
-                ready: None,
-                router: router.finish(),
-                default: self.default.take(),
-            }))
-        } else {
-            Poll::Pending
-        }
+                })
+                .finish();
+
+            Ok(AppRouting { router, default })
+        })
     }
 }
 
 pub struct AppRouting {
     router: Router<HttpService, Guards>,
-    ready: Option<(ServiceRequest, ResourceInfo)>,
-    default: Option<HttpService>,
+    default: HttpService,
 }
 
-impl Service for AppRouting {
-    type Request = ServiceRequest;
+impl Service<ServiceRequest> for AppRouting {
     type Response = ServiceResponse;
     type Error = Error;
-    type Future = BoxResponse;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        if self.ready.is_none() {
-            Poll::Ready(Ok(()))
-        } else {
-            Poll::Pending
-        }
-    }
+    actix_service::always_ready!();
 
-    fn call(&mut self, mut req: ServiceRequest) -> Self::Future {
-        let res = self.router.recognize_mut_checked(&mut req, |req, guards| {
+    fn call(&self, mut req: ServiceRequest) -> Self::Future {
+        let res = self.router.recognize_checked(&mut req, |req, guards| {
             if let Some(ref guards) = guards {
                 for f in guards {
                     if !f.check(req.head()) {
@@ -416,11 +300,8 @@ impl Service for AppRouting {
 
         if let Some((srv, _info)) = res {
             srv.call(req)
-        } else if let Some(ref mut default) = self.default {
-            default.call(req)
         } else {
-            let req = req.into_parts().0;
-            ok(ServiceResponse::new(req, Response::NotFound().finish())).boxed_local()
+            self.default.call(req)
         }
     }
 }
@@ -436,14 +317,13 @@ impl AppEntry {
     }
 }
 
-impl ServiceFactory for AppEntry {
-    type Config = ();
-    type Request = ServiceRequest;
+impl ServiceFactory<ServiceRequest> for AppEntry {
     type Response = ServiceResponse;
     type Error = Error;
-    type InitError = ();
+    type Config = ();
     type Service = AppRouting;
-    type Future = AppRoutingFactoryResponse;
+    type InitError = ();
+    type Future = LocalBoxFuture<'static, Result<Self::Service, Self::InitError>>;
 
     fn new_service(&self, _: ()) -> Self::Future {
         self.factory.borrow_mut().as_mut().unwrap().new_service(())
@@ -455,9 +335,10 @@ mod tests {
     use std::sync::atomic::{AtomicBool, Ordering};
     use std::sync::Arc;
 
+    use actix_service::Service;
+
     use crate::test::{init_service, TestRequest};
     use crate::{web, App, HttpResponse};
-    use actix_service::Service;
 
     struct DropData(Arc<AtomicBool>);
 
@@ -472,7 +353,7 @@ mod tests {
         let data = Arc::new(AtomicBool::new(false));
 
         {
-            let mut app = init_service(
+            let app = init_service(
                 App::new()
                     .data(DropData(data.clone()))
                     .service(web::resource("/test").to(HttpResponse::Ok)),
diff --git a/src/config.rs b/src/config.rs
index 0f49288ec..bd9a25c6f 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -5,7 +5,7 @@ use actix_http::Extensions;
 use actix_router::ResourceDef;
 use actix_service::{boxed, IntoServiceFactory, ServiceFactory};
 
-use crate::data::{Data, DataFactory};
+use crate::data::Data;
 use crate::error::Error;
 use crate::guard::Guard;
 use crate::resource::Resource;
@@ -17,8 +17,7 @@ use crate::service::{
 };
 
 type Guards = Vec<Box<dyn Guard>>;
-type HttpNewService =
-    boxed::BoxServiceFactory<(), ServiceRequest, ServiceResponse, Error, ()>;
+type HttpNewService = boxed::BoxServiceFactory<(), ServiceRequest, ServiceResponse, Error, ()>;
 
 /// Application configuration
 pub struct AppService {
@@ -31,20 +30,14 @@ pub struct AppService {
         Option<Guards>,
         Option<Rc<ResourceMap>>,
     )>,
-    service_data: Rc<Vec<Box<dyn DataFactory>>>,
 }
 
 impl AppService {
-    /// Crate server settings instance
-    pub(crate) fn new(
-        config: AppConfig,
-        default: Rc<HttpNewService>,
-        service_data: Rc<Vec<Box<dyn DataFactory>>>,
-    ) -> Self {
+    /// Crate server settings instance.
+    pub(crate) fn new(config: AppConfig, default: Rc<HttpNewService>) -> Self {
         AppService {
             config,
             default,
-            service_data,
             root: true,
             services: Vec::new(),
         }
@@ -75,7 +68,6 @@ impl AppService {
             default: self.default.clone(),
             services: Vec::new(),
             root: false,
-            service_data: self.service_data.clone(),
         }
     }
 
@@ -89,15 +81,7 @@ impl AppService {
         self.default.clone()
     }
 
-    /// Set global route data
-    pub fn set_service_data(&self, extensions: &mut Extensions) -> bool {
-        for f in self.service_data.iter() {
-            f.create(extensions);
-        }
-        !self.service_data.is_empty()
-    }
-
-    /// Register http service
+    /// Register HTTP service.
     pub fn register_service<F, S>(
         &mut self,
         rdef: ResourceDef,
@@ -105,29 +89,23 @@ impl AppService {
         factory: F,
         nested: Option<Rc<ResourceMap>>,
     ) where
-        F: IntoServiceFactory<S>,
+        F: IntoServiceFactory<S, ServiceRequest>,
         S: ServiceFactory<
+                ServiceRequest,
                 Config = (),
-                Request = ServiceRequest,
                 Response = ServiceResponse,
                 Error = Error,
                 InitError = (),
             > + 'static,
     {
-        self.services.push((
-            rdef,
-            boxed::factory(factory.into_factory()),
-            guards,
-            nested,
-        ));
+        self.services
+            .push((rdef, boxed::factory(factory.into_factory()), guards, nested));
     }
 }
 
 /// Application connection config
 #[derive(Clone)]
-pub struct AppConfig(Rc<AppConfigInner>);
-
-struct AppConfigInner {
+pub struct AppConfig {
     secure: bool,
     host: String,
     addr: SocketAddr,
@@ -135,28 +113,28 @@ struct AppConfigInner {
 
 impl AppConfig {
     pub(crate) fn new(secure: bool, addr: SocketAddr, host: String) -> Self {
-        AppConfig(Rc::new(AppConfigInner { secure, addr, host }))
+        AppConfig { secure, addr, host }
     }
 
     /// Server host name.
     ///
     /// Host name is used by application router as a hostname for url generation.
-    /// Check [ConnectionInfo](./struct.ConnectionInfo.html#method.host)
+    /// Check [ConnectionInfo](super::dev::ConnectionInfo::host())
     /// documentation for more information.
     ///
     /// By default host name is set to a "localhost" value.
     pub fn host(&self) -> &str {
-        &self.0.host
+        &self.host
     }
 
     /// Returns true if connection is secure(https)
     pub fn secure(&self) -> bool {
-        self.0.secure
+        self.secure
     }
 
     /// Returns the socket address of the local half of this TCP connection
     pub fn local_addr(&self) -> SocketAddr {
-        self.0.addr
+        self.addr
     }
 }
 
@@ -170,37 +148,60 @@ impl Default for AppConfig {
     }
 }
 
-/// Service config is used for external configuration.
-/// Part of application configuration could be offloaded
-/// to set of external methods. This could help with
-/// modularization of big application configuration.
+/// Enables parts of app configuration to be declared separately from the app itself. Helpful for
+/// modularizing large applications.
+///
+/// Merge a `ServiceConfig` into an app using [`App::configure`](crate::App::configure). Scope and
+/// resources services have similar methods.
+///
+/// ```
+/// use actix_web::{web, App, HttpResponse};
+///
+/// // this function could be located in different module
+/// fn config(cfg: &mut web::ServiceConfig) {
+///     cfg.service(web::resource("/test")
+///         .route(web::get().to(|| HttpResponse::Ok()))
+///         .route(web::head().to(|| HttpResponse::MethodNotAllowed()))
+///     );
+/// }
+///
+/// // merge `/test` routes from config function to App
+/// App::new().configure(config);
+/// ```
 pub struct ServiceConfig {
     pub(crate) services: Vec<Box<dyn AppServiceFactory>>,
-    pub(crate) data: Vec<Box<dyn DataFactory>>,
     pub(crate) external: Vec<ResourceDef>,
+    pub(crate) app_data: Extensions,
 }
 
 impl ServiceConfig {
     pub(crate) fn new() -> Self {
         Self {
             services: Vec::new(),
-            data: Vec::new(),
             external: Vec::new(),
+            app_data: Extensions::new(),
         }
     }
 
-    /// Set application data. Application data could be accessed
-    /// by using `Data<T>` extractor where `T` is data type.
+    /// Add shared app data item.
     ///
-    /// This is same as `App::data()` method.
-    pub fn data<S: 'static>(&mut self, data: S) -> &mut Self {
-        self.data.push(Box::new(Data::new(data)));
+    /// Counterpart to [`App::data()`](crate::App::data).
+    pub fn data<U: 'static>(&mut self, data: U) -> &mut Self {
+        self.app_data(Data::new(data));
+        self
+    }
+
+    /// Add arbitrary app data item.
+    ///
+    /// Counterpart to [`App::app_data()`](crate::App::app_data).
+    pub fn app_data<U: 'static>(&mut self, ext: U) -> &mut Self {
+        self.app_data.insert(ext);
         self
     }
 
     /// Configure route for a specific path.
     ///
-    /// This is same as `App::route()` method.
+    /// Counterpart to [`App::route()`](crate::App::route).
     pub fn route(&mut self, path: &str, mut route: Route) -> &mut Self {
         self.service(
             Resource::new(path)
@@ -209,9 +210,9 @@ impl ServiceConfig {
         )
     }
 
-    /// Register http service.
+    /// Register HTTP service factory.
     ///
-    /// This is same as `App::service()` method.
+    /// Counterpart to [`App::service()`](crate::App::service).
     pub fn service<F>(&mut self, factory: F) -> &mut Self
     where
         F: HttpServiceFactory + 'static,
@@ -223,11 +224,11 @@ impl ServiceConfig {
 
     /// Register an external resource.
     ///
-    /// External resources are useful for URL generation purposes only
-    /// and are never considered for matching at request time. Calls to
-    /// `HttpRequest::url_for()` will work as expected.
+    /// External resources are useful for URL generation purposes only and are never considered for
+    /// matching at request time. Calls to [`HttpRequest::url_for()`](crate::HttpRequest::url_for)
+    /// will work as expected.
     ///
-    /// This is same as `App::external_service()` method.
+    /// Counterpart to [`App::external_resource()`](crate::App::external_resource).
     pub fn external_resource<N, U>(&mut self, name: N, url: U) -> &mut Self
     where
         N: AsRef<str>,
@@ -254,13 +255,16 @@ mod tests {
     async fn test_data() {
         let cfg = |cfg: &mut ServiceConfig| {
             cfg.data(10usize);
+            cfg.app_data(15u8);
         };
 
-        let mut srv =
-            init_service(App::new().configure(cfg).service(
-                web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok()),
-            ))
-            .await;
+        let srv = init_service(App::new().configure(cfg).service(web::resource("/").to(
+            |_: web::Data<usize>, req: HttpRequest| {
+                assert_eq!(*req.app_data::<u8>().unwrap(), 15u8);
+                HttpResponse::Ok()
+            },
+        )))
+        .await;
         let req = TestRequest::default().to_request();
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::OK);
@@ -277,7 +281,7 @@ mod tests {
     //         });
     //     };
 
-    //     let mut srv =
+    //     let srv =
     //         init_service(App::new().configure(cfg).service(
     //             web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok()),
     //         ));
@@ -288,7 +292,7 @@ mod tests {
     //     let cfg2 = |cfg: &mut ServiceConfig| {
     //         cfg.data_factory(|| Ok::<_, ()>(10u32));
     //     };
-    //     let mut srv = init_service(
+    //     let srv = init_service(
     //         App::new()
     //             .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok()))
     //             .configure(cfg2),
@@ -300,26 +304,22 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_external_resource() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .configure(|cfg| {
-                    cfg.external_resource(
-                        "youtube",
-                        "https://youtube.com/watch/{video_id}",
-                    );
+                    cfg.external_resource("youtube", "https://youtube.com/watch/{video_id}");
                 })
                 .route(
                     "/test",
                     web::get().to(|req: HttpRequest| {
-                        HttpResponse::Ok().body(
-                            req.url_for("youtube", &["12345"]).unwrap().to_string(),
-                        )
+                        HttpResponse::Ok()
+                            .body(req.url_for("youtube", &["12345"]).unwrap().to_string())
                     }),
                 ),
         )
         .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         let body = read_body(resp).await;
         assert_eq!(body, Bytes::from_static(b"https://youtube.com/watch/12345"));
@@ -327,24 +327,22 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_service() {
-        let mut srv = init_service(App::new().configure(|cfg| {
-            cfg.service(
-                web::resource("/test").route(web::get().to(HttpResponse::Created)),
-            )
-            .route("/index.html", web::get().to(HttpResponse::Ok));
+        let srv = init_service(App::new().configure(|cfg| {
+            cfg.service(web::resource("/test").route(web::get().to(HttpResponse::Created)))
+                .route("/index.html", web::get().to(HttpResponse::Ok));
         }))
         .await;
 
         let req = TestRequest::with_uri("/test")
             .method(Method::GET)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::CREATED);
 
         let req = TestRequest::with_uri("/index.html")
             .method(Method::GET)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 }
diff --git a/src/data.rs b/src/data.rs
index 6405fd901..133248212 100644
--- a/src/data.rs
+++ b/src/data.rs
@@ -1,3 +1,4 @@
+use std::any::type_name;
 use std::ops::Deref;
 use std::sync::Arc;
 
@@ -9,8 +10,9 @@ use crate::dev::Payload;
 use crate::extract::FromRequest;
 use crate::request::HttpRequest;
 
-/// Application data factory
+/// Data factory.
 pub(crate) trait DataFactory {
+    /// Return true if modifications were made to extensions map.
     fn create(&self, extensions: &mut Extensions) -> bool;
 }
 
@@ -19,25 +21,20 @@ pub(crate) type FnDataFactory =
 
 /// Application data.
 ///
-/// Application data is an arbitrary data attached to the app.
-/// Application data is available to all routes and could be added
-/// during application configuration process
-/// with `App::data()` method.
+/// Application level data is a piece of arbitrary data attached to the app, scope, or resource.
+/// Application data is available to all routes and can be added during the application
+/// configuration process via `App::data()`.
 ///
-/// Application data could be accessed by using `Data<T>`
-/// extractor where `T` is data type.
+/// Application data can be accessed by using `Data<T>` extractor where `T` is data type.
 ///
-/// **Note**: http server accepts an application factory rather than
-/// an application instance. Http server constructs an application
-/// instance for each thread, thus application data must be constructed
-/// multiple times. If you want to share data between different
-/// threads, a shareable object should be used, e.g. `Send + Sync`. Application
-/// data does not need to be `Send` or `Sync`. Internally `Data` type
-/// uses `Arc`. if your data implements `Send` + `Sync` traits you can
-/// use `web::Data::new()` and avoid double `Arc`.
+/// **Note**: HTTP server accepts an application factory rather than an application instance. HTTP
+/// server constructs an application instance for each thread, thus application data must be
+/// constructed multiple times. If you want to share data between different threads, a shareable
+/// object should be used, e.g. `Send + Sync`. Application data does not need to be `Send`
+/// or `Sync`. Internally `Data` uses `Arc`.
 ///
-/// If route data is not set for a handler, using `Data<T>` extractor would
-/// cause *Internal Server Error* response.
+/// If route data is not set for a handler, using `Data<T>` extractor would cause *Internal
+/// Server Error* response.
 ///
 /// ```rust
 /// use std::sync::Mutex;
@@ -47,7 +44,7 @@ pub(crate) type FnDataFactory =
 ///     counter: usize,
 /// }
 ///
-/// /// Use `Data<T>` extractor to access data in handler.
+/// /// Use the `Data<T>` extractor to access data in a handler.
 /// async fn index(data: web::Data<Mutex<MyData>>) -> impl Responder {
 ///     let mut data = data.lock().unwrap();
 ///     data.counter += 1;
@@ -70,10 +67,6 @@ pub struct Data<T: ?Sized>(Arc<T>);
 
 impl<T> Data<T> {
     /// Create new `Data` instance.
-    ///
-    /// Internally `Data` type uses `Arc`. if your data implements
-    /// `Send` + `Sync` traits you can use `web::Data::new()` and
-    /// avoid double `Arc`.
     pub fn new(state: T) -> Data<T> {
         Data(Arc::new(state))
     }
@@ -121,8 +114,9 @@ impl<T: ?Sized + 'static> FromRequest for Data<T> {
         } else {
             log::debug!(
                 "Failed to construct App-level Data extractor. \
-                 Request path: {:?}",
-                req.path()
+                 Request path: {:?} (type: {})",
+                req.path(),
+                type_name::<T>(),
             );
             err(ErrorInternalServerError(
                 "App data is not configured, to configure use App::data()",
@@ -133,12 +127,8 @@ impl<T: ?Sized + 'static> FromRequest for Data<T> {
 
 impl<T: ?Sized + 'static> DataFactory for Data<T> {
     fn create(&self, extensions: &mut Extensions) -> bool {
-        if !extensions.contains::<Data<T>>() {
-            extensions.insert(Data(self.0.clone()));
-            true
-        } else {
-            false
-        }
+        extensions.insert(Data(self.0.clone()));
+        true
     }
 }
 
@@ -154,7 +144,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_data_extractor() {
-        let mut srv = init_service(App::new().data("TEST".to_string()).service(
+        let srv = init_service(App::new().data("TEST".to_string()).service(
             web::resource("/").to(|data: web::Data<String>| {
                 assert_eq!(data.to_lowercase(), "test");
                 HttpResponse::Ok()
@@ -166,33 +156,54 @@ mod tests {
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::OK);
 
-        let mut srv =
-            init_service(App::new().data(10u32).service(
-                web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok()),
-            ))
-            .await;
+        let srv = init_service(
+            App::new()
+                .data(10u32)
+                .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok())),
+        )
+        .await;
         let req = TestRequest::default().to_request();
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR);
+
+        let srv = init_service(
+            App::new()
+                .data(10u32)
+                .data(13u32)
+                .app_data(12u64)
+                .app_data(15u64)
+                .default_service(web::to(|n: web::Data<u32>, req: HttpRequest| {
+                    // in each case, the latter insertion should be preserved
+                    assert_eq!(*req.app_data::<u64>().unwrap(), 15);
+                    assert_eq!(*n.into_inner(), 13);
+                    HttpResponse::Ok()
+                })),
+        )
+        .await;
+        let req = TestRequest::default().to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
     }
 
     #[actix_rt::test]
     async fn test_app_data_extractor() {
-        let mut srv =
-            init_service(App::new().app_data(Data::new(10usize)).service(
-                web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok()),
-            ))
-            .await;
+        let srv = init_service(
+            App::new()
+                .app_data(Data::new(10usize))
+                .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok())),
+        )
+        .await;
 
         let req = TestRequest::default().to_request();
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::OK);
 
-        let mut srv =
-            init_service(App::new().app_data(Data::new(10u32)).service(
-                web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok()),
-            ))
-            .await;
+        let srv = init_service(
+            App::new()
+                .app_data(Data::new(10u32))
+                .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok())),
+        )
+        .await;
         let req = TestRequest::default().to_request();
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR);
@@ -200,7 +211,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_route_data_extractor() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::resource("/")
                     .data(10usize)
@@ -214,7 +225,7 @@ mod tests {
         assert_eq!(resp.status(), StatusCode::OK);
 
         // different type
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::resource("/")
                     .data(10u32)
@@ -229,15 +240,16 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_override_data() {
-        let mut srv = init_service(App::new().data(1usize).service(
-            web::resource("/").data(10usize).route(web::get().to(
-                |data: web::Data<usize>| {
-                    assert_eq!(**data, 10);
-                    HttpResponse::Ok()
-                },
-            )),
-        ))
-        .await;
+        let srv =
+            init_service(App::new().data(1usize).service(
+                web::resource("/").data(10usize).route(web::get().to(
+                    |data: web::Data<usize>| {
+                        assert_eq!(**data, 10);
+                        HttpResponse::Ok()
+                    },
+                )),
+            ))
+            .await;
 
         let req = TestRequest::default().to_request();
         let resp = srv.call(req).await.unwrap();
diff --git a/src/error.rs b/src/error.rs
index 659ba05fd..0865257d3 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -1,11 +1,11 @@
 //! Error and Result module
+
 pub use actix_http::error::*;
-use derive_more::{Display, From};
+use derive_more::{Display, Error, From};
 use serde_json::error::Error as JsonError;
 use url::ParseError as UrlParseError;
 
-use crate::http::StatusCode;
-use crate::HttpResponse;
+use crate::{http::StatusCode, HttpResponse};
 
 /// Errors which can occur when attempting to generate resource uri.
 #[derive(Debug, PartialEq, Display, From)]
@@ -13,9 +13,11 @@ pub enum UrlGenerationError {
     /// Resource not found
     #[display(fmt = "Resource not found")]
     ResourceNotFound,
+
     /// Not all path pattern covered
     #[display(fmt = "Not all path pattern covered")]
     NotEnoughElements,
+
     /// URL parse error
     #[display(fmt = "{}", _0)]
     ParseError(UrlParseError),
@@ -27,34 +29,37 @@ impl std::error::Error for UrlGenerationError {}
 impl ResponseError for UrlGenerationError {}
 
 /// A set of errors that can occur during parsing urlencoded payloads
-#[derive(Debug, Display, From)]
+#[derive(Debug, Display, Error, From)]
 pub enum UrlencodedError {
-    /// Can not decode chunked transfer encoding
-    #[display(fmt = "Can not decode chunked transfer encoding")]
+    /// Can not decode chunked transfer encoding.
+    #[display(fmt = "Can not decode chunked transfer encoding.")]
     Chunked,
-    /// Payload size is bigger than allowed. (default: 256kB)
+
+    /// Payload size is larger than allowed. (default limit: 256kB).
     #[display(
-        fmt = "Urlencoded payload size is bigger ({} bytes) than allowed (default: {} bytes)",
+        fmt = "URL encoded payload is larger ({} bytes) than allowed (limit: {} bytes).",
         size,
         limit
     )]
     Overflow { size: usize, limit: usize },
-    /// Payload size is now known
-    #[display(fmt = "Payload size is now known")]
+
+    /// Payload size is now known.
+    #[display(fmt = "Payload size is now known.")]
     UnknownLength,
-    /// Content type error
-    #[display(fmt = "Content type error")]
+
+    /// Content type error.
+    #[display(fmt = "Content type error.")]
     ContentType,
-    /// Parse error
-    #[display(fmt = "Parse error")]
+
+    /// Parse error.
+    #[display(fmt = "Parse error.")]
     Parse,
-    /// Payload error
-    #[display(fmt = "Error that occur during reading payload: {}", _0)]
+
+    /// Payload error.
+    #[display(fmt = "Error that occur during reading payload: {}.", _0)]
     Payload(PayloadError),
 }
 
-impl std::error::Error for UrlencodedError {}
-
 /// Return `BadRequest` for `UrlencodedError`
 impl ResponseError for UrlencodedError {
     fn status_code(&self) -> StatusCode {
@@ -89,9 +94,7 @@ impl std::error::Error for JsonPayloadError {}
 impl ResponseError for JsonPayloadError {
     fn error_response(&self) -> HttpResponse {
         match *self {
-            JsonPayloadError::Overflow => {
-                HttpResponse::new(StatusCode::PAYLOAD_TOO_LARGE)
-            }
+            JsonPayloadError::Overflow => HttpResponse::new(StatusCode::PAYLOAD_TOO_LARGE),
             _ => HttpResponse::new(StatusCode::BAD_REQUEST),
         }
     }
@@ -114,16 +117,14 @@ impl ResponseError for PathError {
     }
 }
 
-/// A set of errors that can occur during parsing query strings
-#[derive(Debug, Display, From)]
+/// A set of errors that can occur during parsing query strings.
+#[derive(Debug, Display, Error, From)]
 pub enum QueryPayloadError {
-    /// Deserialize error
+    /// Query deserialize error.
     #[display(fmt = "Query deserialize error: {}", _0)]
     Deserialize(serde::de::value::Error),
 }
 
-impl std::error::Error for QueryPayloadError {}
-
 /// Return `BadRequest` for `QueryPayloadError`
 impl ResponseError for QueryPayloadError {
     fn status_code(&self) -> StatusCode {
diff --git a/src/extract.rs b/src/extract.rs
index df9c34cb3..7a677bca4 100644
--- a/src/extract.rs
+++ b/src/extract.rs
@@ -1,33 +1,37 @@
 //! Request extractors
-use std::future::Future;
-use std::pin::Pin;
-use std::task::{Context, Poll};
 
-use actix_http::error::Error;
-use futures_util::future::{ok, FutureExt, LocalBoxFuture, Ready};
+use std::{
+    future::Future,
+    pin::Pin,
+    task::{Context, Poll},
+};
 
-use crate::dev::Payload;
-use crate::request::HttpRequest;
+use futures_util::{
+    future::{ready, Ready},
+    ready,
+};
+
+use crate::{dev::Payload, Error, HttpRequest};
 
 /// Trait implemented by types that can be extracted from request.
 ///
 /// Types that implement this trait can be used with `Route` handlers.
 pub trait FromRequest: Sized {
+    /// Configuration for this extractor.
+    type Config: Default + 'static;
+
     /// The associated error which can be returned.
     type Error: Into<Error>;
 
-    /// Future that resolves to a Self
+    /// Future that resolves to a Self.
     type Future: Future<Output = Result<Self, Self::Error>>;
 
-    /// Configuration for this extractor
-    type Config: Default + 'static;
-
-    /// Convert request to a Self
+    /// Create a Self from request parts asynchronously.
     fn from_request(req: &HttpRequest, payload: &mut Payload) -> Self::Future;
 
-    /// Convert request to a Self
+    /// Create a Self from request head asynchronously.
     ///
-    /// This method uses `Payload::None` as payload stream.
+    /// This method is short for `T::from_request(req, &mut Payload::None)`.
     fn extract(req: &HttpRequest) -> Self::Future {
         Self::from_request(req, &mut Payload::None)
     }
@@ -95,21 +99,41 @@ where
     T: FromRequest,
     T::Future: 'static,
 {
-    type Config = T::Config;
     type Error = Error;
-    type Future = LocalBoxFuture<'static, Result<Option<T>, Error>>;
+    type Future = FromRequestOptFuture<T::Future>;
+    type Config = T::Config;
 
     #[inline]
     fn from_request(req: &HttpRequest, payload: &mut Payload) -> Self::Future {
-        T::from_request(req, payload)
-            .then(|r| match r {
-                Ok(v) => ok(Some(v)),
-                Err(e) => {
-                    log::debug!("Error for Option<T> extractor: {}", e.into());
-                    ok(None)
-                }
-            })
-            .boxed_local()
+        FromRequestOptFuture {
+            fut: T::from_request(req, payload),
+        }
+    }
+}
+
+#[pin_project::pin_project]
+pub struct FromRequestOptFuture<Fut> {
+    #[pin]
+    fut: Fut,
+}
+
+impl<Fut, T, E> Future for FromRequestOptFuture<Fut>
+where
+    Fut: Future<Output = Result<T, E>>,
+    E: Into<Error>,
+{
+    type Output = Result<Option<T>, Error>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.project();
+        let res = ready!(this.fut.poll(cx));
+        match res {
+            Ok(t) => Poll::Ready(Ok(Some(t))),
+            Err(e) => {
+                log::debug!("Error for Option<T> extractor: {}", e.into());
+                Poll::Ready(Ok(None))
+            }
+        }
     }
 }
 
@@ -165,29 +189,45 @@ where
     T::Error: 'static,
     T::Future: 'static,
 {
-    type Config = T::Config;
     type Error = Error;
-    type Future = LocalBoxFuture<'static, Result<Result<T, T::Error>, Error>>;
+    type Future = FromRequestResFuture<T::Future>;
+    type Config = T::Config;
 
     #[inline]
     fn from_request(req: &HttpRequest, payload: &mut Payload) -> Self::Future {
-        T::from_request(req, payload)
-            .then(|res| match res {
-                Ok(v) => ok(Ok(v)),
-                Err(e) => ok(Err(e)),
-            })
-            .boxed_local()
+        FromRequestResFuture {
+            fut: T::from_request(req, payload),
+        }
+    }
+}
+
+#[pin_project::pin_project]
+pub struct FromRequestResFuture<Fut> {
+    #[pin]
+    fut: Fut,
+}
+
+impl<Fut, T, E> Future for FromRequestResFuture<Fut>
+where
+    Fut: Future<Output = Result<T, E>>,
+{
+    type Output = Result<Result<T, E>, Error>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.project();
+        let res = ready!(this.fut.poll(cx));
+        Poll::Ready(Ok(res))
     }
 }
 
 #[doc(hidden)]
 impl FromRequest for () {
-    type Config = ();
     type Error = Error;
     type Future = Ready<Result<(), Error>>;
+    type Config = ();
 
     fn from_request(_: &HttpRequest, _: &mut Payload) -> Self::Future {
-        ok(())
+        ready(Ok(()))
     }
 }
 
@@ -307,25 +347,21 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_option() {
-        let (req, mut pl) = TestRequest::with_header(
-            header::CONTENT_TYPE,
-            "application/x-www-form-urlencoded",
-        )
-        .data(FormConfig::default().limit(4096))
-        .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((header::CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .data(FormConfig::default().limit(4096))
+            .to_http_parts();
 
         let r = Option::<Form<Info>>::from_request(&req, &mut pl)
             .await
             .unwrap();
         assert_eq!(r, None);
 
-        let (req, mut pl) = TestRequest::with_header(
-            header::CONTENT_TYPE,
-            "application/x-www-form-urlencoded",
-        )
-        .header(header::CONTENT_LENGTH, "9")
-        .set_payload(Bytes::from_static(b"hello=world"))
-        .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((header::CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .insert_header((header::CONTENT_LENGTH, "9"))
+            .set_payload(Bytes::from_static(b"hello=world"))
+            .to_http_parts();
 
         let r = Option::<Form<Info>>::from_request(&req, &mut pl)
             .await
@@ -337,13 +373,11 @@ mod tests {
             }))
         );
 
-        let (req, mut pl) = TestRequest::with_header(
-            header::CONTENT_TYPE,
-            "application/x-www-form-urlencoded",
-        )
-        .header(header::CONTENT_LENGTH, "9")
-        .set_payload(Bytes::from_static(b"bye=world"))
-        .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((header::CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .insert_header((header::CONTENT_LENGTH, "9"))
+            .set_payload(Bytes::from_static(b"bye=world"))
+            .to_http_parts();
 
         let r = Option::<Form<Info>>::from_request(&req, &mut pl)
             .await
@@ -353,13 +387,11 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_result() {
-        let (req, mut pl) = TestRequest::with_header(
-            header::CONTENT_TYPE,
-            "application/x-www-form-urlencoded",
-        )
-        .header(header::CONTENT_LENGTH, "11")
-        .set_payload(Bytes::from_static(b"hello=world"))
-        .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((header::CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .insert_header((header::CONTENT_LENGTH, "11"))
+            .set_payload(Bytes::from_static(b"hello=world"))
+            .to_http_parts();
 
         let r = Result::<Form<Info>, Error>::from_request(&req, &mut pl)
             .await
@@ -372,13 +404,11 @@ mod tests {
             })
         );
 
-        let (req, mut pl) = TestRequest::with_header(
-            header::CONTENT_TYPE,
-            "application/x-www-form-urlencoded",
-        )
-        .header(header::CONTENT_LENGTH, "9")
-        .set_payload(Bytes::from_static(b"bye=world"))
-        .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((header::CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .insert_header((header::CONTENT_LENGTH, 9))
+            .set_payload(Bytes::from_static(b"bye=world"))
+            .to_http_parts();
 
         let r = Result::<Form<Info>, Error>::from_request(&req, &mut pl)
             .await
diff --git a/src/guard.rs b/src/guard.rs
index 25284236a..5d0de58c2 100644
--- a/src/guard.rs
+++ b/src/guard.rs
@@ -176,7 +176,7 @@ impl Guard for NotGuard {
     }
 }
 
-/// Http method guard
+/// HTTP method guard.
 #[doc(hidden)]
 pub struct MethodGuard(http::Method);
 
@@ -186,52 +186,52 @@ impl Guard for MethodGuard {
     }
 }
 
-/// Guard to match *GET* http method
+/// Guard to match *GET* HTTP method.
 pub fn Get() -> MethodGuard {
     MethodGuard(http::Method::GET)
 }
 
-/// Predicate to match *POST* http method
+/// Predicate to match *POST* HTTP method.
 pub fn Post() -> MethodGuard {
     MethodGuard(http::Method::POST)
 }
 
-/// Predicate to match *PUT* http method
+/// Predicate to match *PUT* HTTP method.
 pub fn Put() -> MethodGuard {
     MethodGuard(http::Method::PUT)
 }
 
-/// Predicate to match *DELETE* http method
+/// Predicate to match *DELETE* HTTP method.
 pub fn Delete() -> MethodGuard {
     MethodGuard(http::Method::DELETE)
 }
 
-/// Predicate to match *HEAD* http method
+/// Predicate to match *HEAD* HTTP method.
 pub fn Head() -> MethodGuard {
     MethodGuard(http::Method::HEAD)
 }
 
-/// Predicate to match *OPTIONS* http method
+/// Predicate to match *OPTIONS* HTTP method.
 pub fn Options() -> MethodGuard {
     MethodGuard(http::Method::OPTIONS)
 }
 
-/// Predicate to match *CONNECT* http method
+/// Predicate to match *CONNECT* HTTP method.
 pub fn Connect() -> MethodGuard {
     MethodGuard(http::Method::CONNECT)
 }
 
-/// Predicate to match *PATCH* http method
+/// Predicate to match *PATCH* HTTP method.
 pub fn Patch() -> MethodGuard {
     MethodGuard(http::Method::PATCH)
 }
 
-/// Predicate to match *TRACE* http method
+/// Predicate to match *TRACE* HTTP method.
 pub fn Trace() -> MethodGuard {
     MethodGuard(http::Method::TRACE)
 }
 
-/// Predicate to match specified http method
+/// Predicate to match specified HTTP method.
 pub fn Method(method: http::Method) -> MethodGuard {
     MethodGuard(method)
 }
@@ -330,7 +330,8 @@ mod tests {
 
     #[test]
     fn test_header() {
-        let req = TestRequest::with_header(header::TRANSFER_ENCODING, "chunked")
+        let req = TestRequest::default()
+            .insert_header((header::TRANSFER_ENCODING, "chunked"))
             .to_http_request();
 
         let pred = Header("transfer-encoding", "chunked");
@@ -346,10 +347,10 @@ mod tests {
     #[test]
     fn test_host() {
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::HOST,
                 header::HeaderValue::from_static("www.rust-lang.org"),
-            )
+            ))
             .to_http_request();
 
         let pred = Host("www.rust-lang.org");
@@ -374,10 +375,10 @@ mod tests {
     #[test]
     fn test_host_scheme() {
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::HOST,
                 header::HeaderValue::from_static("https://www.rust-lang.org"),
-            )
+            ))
             .to_http_request();
 
         let pred = Host("www.rust-lang.org").scheme("https");
diff --git a/src/handler.rs b/src/handler.rs
index 669512ab3..0016b741e 100644
--- a/src/handler.rs
+++ b/src/handler.rs
@@ -1,4 +1,3 @@
-use std::convert::Infallible;
 use std::future::Future;
 use std::marker::PhantomData;
 use std::pin::Pin;
@@ -6,7 +5,7 @@ use std::task::{Context, Poll};
 
 use actix_http::{Error, Response};
 use actix_service::{Service, ServiceFactory};
-use futures_util::future::{ok, Ready};
+use futures_util::future::{ready, Ready};
 use futures_util::ready;
 use pin_project::pin_project;
 
@@ -15,20 +14,25 @@ use crate::request::HttpRequest;
 use crate::responder::Responder;
 use crate::service::{ServiceRequest, ServiceResponse};
 
-/// Async handler converter factory
-pub trait Factory<T, R, O>: Clone + 'static
+///  A request handler is an async function that accepts zero or more parameters that can be
+///  extracted from a request (ie, [`impl FromRequest`](crate::FromRequest)) and returns a type that can be converted into
+///  an [`HttpResponse`](crate::HttpResponse) (ie, [`impl Responder`](crate::Responder)).
+///
+/// If you got the error `the trait Handler<_, _, _> is not implemented`, then your function is not
+/// a valid handler. See [Request Handlers](https://actix.rs/docs/handlers/) for more information.
+pub trait Handler<T, R>: Clone + 'static
 where
-    R: Future<Output = O>,
-    O: Responder,
+    R: Future,
+    R::Output: Responder,
 {
     fn call(&self, param: T) -> R;
 }
 
-impl<F, R, O> Factory<(), R, O> for F
+impl<F, R> Handler<(), R> for F
 where
     F: Fn() -> R + Clone + 'static,
-    R: Future<Output = O>,
-    O: Responder,
+    R: Future,
+    R::Output: Responder,
 {
     fn call(&self, _: ()) -> R {
         (self)()
@@ -36,226 +40,137 @@ where
 }
 
 #[doc(hidden)]
-pub struct Handler<F, T, R, O>
+/// Extract arguments from request, run factory function and make response.
+pub struct HandlerService<F, T, R>
 where
-    F: Factory<T, R, O>,
-    R: Future<Output = O>,
-    O: Responder,
+    F: Handler<T, R>,
+    T: FromRequest,
+    R: Future,
+    R::Output: Responder,
 {
     hnd: F,
-    _t: PhantomData<(T, R, O)>,
+    _phantom: PhantomData<(T, R)>,
 }
 
-impl<F, T, R, O> Handler<F, T, R, O>
+impl<F, T, R> HandlerService<F, T, R>
 where
-    F: Factory<T, R, O>,
-    R: Future<Output = O>,
-    O: Responder,
+    F: Handler<T, R>,
+    T: FromRequest,
+    R: Future,
+    R::Output: Responder,
 {
     pub fn new(hnd: F) -> Self {
-        Handler {
+        Self {
             hnd,
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
 
-impl<F, T, R, O> Clone for Handler<F, T, R, O>
+impl<F, T, R> Clone for HandlerService<F, T, R>
 where
-    F: Factory<T, R, O>,
-    R: Future<Output = O>,
-    O: Responder,
+    F: Handler<T, R>,
+    T: FromRequest,
+    R: Future,
+    R::Output: Responder,
 {
     fn clone(&self) -> Self {
-        Handler {
+        Self {
             hnd: self.hnd.clone(),
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
 
-impl<F, T, R, O> Service for Handler<F, T, R, O>
+impl<F, T, R> ServiceFactory<ServiceRequest> for HandlerService<F, T, R>
 where
-    F: Factory<T, R, O>,
-    R: Future<Output = O>,
-    O: Responder,
+    F: Handler<T, R>,
+    T: FromRequest,
+    R: Future,
+    R::Output: Responder,
 {
-    type Request = (T, HttpRequest);
     type Response = ServiceResponse;
-    type Error = Infallible;
-    type Future = HandlerServiceResponse<R, O>;
+    type Error = Error;
+    type Config = ();
+    type Service = Self;
+    type InitError = ();
+    type Future = Ready<Result<Self::Service, ()>>;
 
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    fn new_service(&self, _: ()) -> Self::Future {
+        ready(Ok(self.clone()))
+    }
+}
+
+/// HandlerService is both it's ServiceFactory and Service Type.
+impl<F, T, R> Service<ServiceRequest> for HandlerService<F, T, R>
+where
+    F: Handler<T, R>,
+    T: FromRequest,
+    R: Future,
+    R::Output: Responder,
+{
+    type Response = ServiceResponse;
+    type Error = Error;
+    type Future = HandlerServiceFuture<F, T, R>;
+
+    fn poll_ready(&self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         Poll::Ready(Ok(()))
     }
 
-    fn call(&mut self, (param, req): (T, HttpRequest)) -> Self::Future {
-        HandlerServiceResponse {
-            fut: self.hnd.call(param),
-            fut2: None,
-            req: Some(req),
-        }
+    fn call(&self, req: ServiceRequest) -> Self::Future {
+        let (req, mut payload) = req.into_parts();
+        let fut = T::from_request(&req, &mut payload);
+        HandlerServiceFuture::Extract(fut, Some(req), self.hnd.clone())
     }
 }
 
 #[doc(hidden)]
-#[pin_project]
-pub struct HandlerServiceResponse<T, R>
+#[pin_project(project = HandlerProj)]
+pub enum HandlerServiceFuture<F, T, R>
 where
-    T: Future<Output = R>,
-    R: Responder,
+    F: Handler<T, R>,
+    T: FromRequest,
+    R: Future,
+    R::Output: Responder,
 {
-    #[pin]
-    fut: T,
-    #[pin]
-    fut2: Option<R::Future>,
-    req: Option<HttpRequest>,
+    Extract(#[pin] T::Future, Option<HttpRequest>, F),
+    Handle(#[pin] R, Option<HttpRequest>),
 }
 
-impl<T, R> Future for HandlerServiceResponse<T, R>
+impl<F, T, R> Future for HandlerServiceFuture<F, T, R>
 where
-    T: Future<Output = R>,
-    R: Responder,
+    F: Handler<T, R>,
+    T: FromRequest,
+    R: Future,
+    R::Output: Responder,
 {
-    type Output = Result<ServiceResponse, Infallible>;
+    // Error type in this future is a placeholder type.
+    // all instances of error must be converted to ServiceResponse and return in Ok.
+    type Output = Result<ServiceResponse, Error>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.as_mut().project();
-
-        if let Some(fut) = this.fut2.as_pin_mut() {
-            return match fut.poll(cx) {
-                Poll::Ready(Ok(res)) => {
-                    Poll::Ready(Ok(ServiceResponse::new(this.req.take().unwrap(), res)))
+        loop {
+            match self.as_mut().project() {
+                HandlerProj::Extract(fut, req, handle) => {
+                    match ready!(fut.poll(cx)) {
+                        Ok(item) => {
+                            let fut = handle.call(item);
+                            let state = HandlerServiceFuture::Handle(fut, req.take());
+                            self.as_mut().set(state);
+                        }
+                        Err(e) => {
+                            let res: Response = e.into().into();
+                            let req = req.take().unwrap();
+                            return Poll::Ready(Ok(ServiceResponse::new(req, res)));
+                        }
+                    };
                 }
-                Poll::Pending => Poll::Pending,
-                Poll::Ready(Err(e)) => {
-                    let res: Response = e.into().into();
-                    Poll::Ready(Ok(ServiceResponse::new(this.req.take().unwrap(), res)))
+                HandlerProj::Handle(fut, req) => {
+                    let res = ready!(fut.poll(cx));
+                    let req = req.take().unwrap();
+                    let res = res.respond_to(&req);
+                    return Poll::Ready(Ok(ServiceResponse::new(req, res)));
                 }
-            };
-        }
-
-        match this.fut.poll(cx) {
-            Poll::Ready(res) => {
-                let fut = res.respond_to(this.req.as_ref().unwrap());
-                self.as_mut().project().fut2.set(Some(fut));
-                self.poll(cx)
-            }
-            Poll::Pending => Poll::Pending,
-        }
-    }
-}
-
-/// Extract arguments from request
-pub struct Extract<T: FromRequest, S> {
-    service: S,
-    _t: PhantomData<T>,
-}
-
-impl<T: FromRequest, S> Extract<T, S> {
-    pub fn new(service: S) -> Self {
-        Extract {
-            service,
-            _t: PhantomData,
-        }
-    }
-}
-
-impl<T: FromRequest, S> ServiceFactory for Extract<T, S>
-where
-    S: Service<
-            Request = (T, HttpRequest),
-            Response = ServiceResponse,
-            Error = Infallible,
-        > + Clone,
-{
-    type Config = ();
-    type Request = ServiceRequest;
-    type Response = ServiceResponse;
-    type Error = (Error, ServiceRequest);
-    type InitError = ();
-    type Service = ExtractService<T, S>;
-    type Future = Ready<Result<Self::Service, ()>>;
-
-    fn new_service(&self, _: ()) -> Self::Future {
-        ok(ExtractService {
-            _t: PhantomData,
-            service: self.service.clone(),
-        })
-    }
-}
-
-pub struct ExtractService<T: FromRequest, S> {
-    service: S,
-    _t: PhantomData<T>,
-}
-
-impl<T: FromRequest, S> Service for ExtractService<T, S>
-where
-    S: Service<
-            Request = (T, HttpRequest),
-            Response = ServiceResponse,
-            Error = Infallible,
-        > + Clone,
-{
-    type Request = ServiceRequest;
-    type Response = ServiceResponse;
-    type Error = (Error, ServiceRequest);
-    type Future = ExtractResponse<T, S>;
-
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
-
-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
-        let (req, mut payload) = req.into_parts();
-        let fut = T::from_request(&req, &mut payload);
-
-        ExtractResponse {
-            fut,
-            req,
-            fut_s: None,
-            service: self.service.clone(),
-        }
-    }
-}
-
-#[pin_project]
-pub struct ExtractResponse<T: FromRequest, S: Service> {
-    req: HttpRequest,
-    service: S,
-    #[pin]
-    fut: T::Future,
-    #[pin]
-    fut_s: Option<S::Future>,
-}
-
-impl<T: FromRequest, S> Future for ExtractResponse<T, S>
-where
-    S: Service<
-        Request = (T, HttpRequest),
-        Response = ServiceResponse,
-        Error = Infallible,
-    >,
-{
-    type Output = Result<ServiceResponse, (Error, ServiceRequest)>;
-
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.as_mut().project();
-
-        if let Some(fut) = this.fut_s.as_pin_mut() {
-            return fut.poll(cx).map_err(|_| panic!());
-        }
-
-        match ready!(this.fut.poll(cx)) {
-            Err(e) => {
-                let req = ServiceRequest::new(this.req.clone());
-                Poll::Ready(Err((e.into(), req)))
-            }
-            Ok(item) => {
-                let fut = Some(this.service.call((item, this.req.clone())));
-                self.as_mut().project().fut_s.set(fut);
-                self.poll(cx)
             }
         }
     }
@@ -263,10 +178,10 @@ where
 
 /// FromRequest trait impl for tuples
 macro_rules! factory_tuple ({ $(($n:tt, $T:ident)),+} => {
-    impl<Func, $($T,)+ Res, O> Factory<($($T,)+), Res, O> for Func
+    impl<Func, $($T,)+ Res> Handler<($($T,)+), Res> for Func
     where Func: Fn($($T,)+) -> Res + Clone + 'static,
-          Res: Future<Output = O>,
-          O: Responder,
+          Res: Future,
+          Res::Output: Responder,
     {
         fn call(&self, param: ($($T,)+)) -> Res {
             (self)($(param.$n,)+)
@@ -278,14 +193,14 @@ macro_rules! factory_tuple ({ $(($n:tt, $T:ident)),+} => {
 mod m {
     use super::*;
 
-factory_tuple!((0, A));
-factory_tuple!((0, A), (1, B));
-factory_tuple!((0, A), (1, B), (2, C));
-factory_tuple!((0, A), (1, B), (2, C), (3, D));
-factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E));
-factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F));
-factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G));
-factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H));
-factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H), (8, I));
-factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H), (8, I), (9, J));
+    factory_tuple!((0, A));
+    factory_tuple!((0, A), (1, B));
+    factory_tuple!((0, A), (1, B), (2, C));
+    factory_tuple!((0, A), (1, B), (2, C), (3, D));
+    factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E));
+    factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F));
+    factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G));
+    factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H));
+    factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H), (8, I));
+    factory_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H), (8, I), (9, J));
 }
diff --git a/src/info.rs b/src/info.rs
index 1d9b402a7..c9ddf6ec4 100644
--- a/src/info.rs
+++ b/src/info.rs
@@ -55,7 +55,7 @@ impl ConnectionInfo {
                                             host = Some(val.trim());
                                         }
                                     }
-                                    _ => (),
+                                    _ => {}
                                 }
                             }
                         }
@@ -174,7 +174,7 @@ impl ConnectionInfo {
     /// Do not use this function for security purposes, unless you can ensure the Forwarded and
     /// X-Forwarded-For headers cannot be spoofed by the client. If you want the client's socket
     /// address explicitly, use
-    /// [`HttpRequest::peer_addr()`](../web/struct.HttpRequest.html#method.peer_addr) instead.
+    /// [`HttpRequest::peer_addr()`](super::web::HttpRequest::peer_addr()) instead.
     #[inline]
     pub fn realip_remote_addr(&self) -> Option<&str> {
         if let Some(ref r) = self.realip_remote_addr {
@@ -200,10 +200,10 @@ mod tests {
         assert_eq!(info.host(), "localhost:8080");
 
         let req = TestRequest::default()
-            .header(
+            .insert_header((
                 header::FORWARDED,
                 "for=192.0.2.60; proto=https; by=203.0.113.43; host=rust-lang.org",
-            )
+            ))
             .to_http_request();
 
         let info = req.connection_info();
@@ -212,7 +212,7 @@ mod tests {
         assert_eq!(info.realip_remote_addr(), Some("192.0.2.60"));
 
         let req = TestRequest::default()
-            .header(header::HOST, "rust-lang.org")
+            .insert_header((header::HOST, "rust-lang.org"))
             .to_http_request();
 
         let info = req.connection_info();
@@ -221,20 +221,20 @@ mod tests {
         assert_eq!(info.realip_remote_addr(), None);
 
         let req = TestRequest::default()
-            .header(X_FORWARDED_FOR, "192.0.2.60")
+            .insert_header((X_FORWARDED_FOR, "192.0.2.60"))
             .to_http_request();
         let info = req.connection_info();
         assert_eq!(info.realip_remote_addr(), Some("192.0.2.60"));
 
         let req = TestRequest::default()
-            .header(X_FORWARDED_HOST, "192.0.2.60")
+            .insert_header((X_FORWARDED_HOST, "192.0.2.60"))
             .to_http_request();
         let info = req.connection_info();
         assert_eq!(info.host(), "192.0.2.60");
         assert_eq!(info.realip_remote_addr(), None);
 
         let req = TestRequest::default()
-            .header(X_FORWARDED_PROTO, "https")
+            .insert_header((X_FORWARDED_PROTO, "https"))
             .to_http_request();
         let info = req.connection_info();
         assert_eq!(info.scheme(), "https");
diff --git a/src/lib.rs b/src/lib.rs
index 327cba954..16b2ab186 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-//! Actix web is a powerful, pragmatic, and extremely fast web framework for Rust.
+//! Actix Web is a powerful, pragmatic, and extremely fast web framework for Rust.
 //!
 //! ## Example
 //!
@@ -6,7 +6,8 @@
 //! use actix_web::{get, web, App, HttpServer, Responder};
 //!
 //! #[get("/{id}/{name}/index.html")]
-//! async fn index(web::Path((id, name)): web::Path<(u32, String)>) -> impl Responder {
+//! async fn index(path: web::Path<(u32, String)>) -> impl Responder {
+//!     let (id, name) = path.into_inner();
 //!     format!("Hello {}! id:{}", name, id)
 //! }
 //!
@@ -29,16 +30,16 @@
 //!
 //! To get started navigating the API docs, you may consider looking at the following pages first:
 //!
-//! * [App](struct.App.html): This struct represents an Actix web application and is used to
+//! * [App]: This struct represents an Actix Web application and is used to
 //!   configure routes and other common application settings.
 //!
-//! * [HttpServer](struct.HttpServer.html): This struct represents an HTTP server instance and is
+//! * [HttpServer]: This struct represents an HTTP server instance and is
 //!   used to instantiate and configure servers.
 //!
-//! * [web](web/index.html): This module provides essential types for route registration as well as
+//! * [web]: This module provides essential types for route registration as well as
 //!   common utilities for request handlers.
 //!
-//! * [HttpRequest](struct.HttpRequest.html) and [HttpResponse](struct.HttpResponse.html): These
+//! * [HttpRequest] and [HttpResponse]: These
 //!   structs represent HTTP requests and responses and expose methods for creating, inspecting,
 //!   and otherwise utilizing them.
 //!
@@ -55,21 +56,26 @@
 //! * SSL support using OpenSSL or Rustls
 //! * Middlewares ([Logger, Session, CORS, etc](https://actix.rs/docs/middleware/))
 //! * Includes an async [HTTP client](https://actix.rs/actix-web/actix_web/client/index.html)
-//! * Supports [Actix actor framework](https://github.com/actix/actix)
-//! * Runs on stable Rust 1.42+
+//! * Runs on stable Rust 1.46+
 //!
 //! ## Crate Features
 //!
 //! * `compress` - content encoding compression support (enabled by default)
+//! * `cookies` - cookies support (enabled by default)
 //! * `openssl` - HTTPS support via `openssl` crate, supports `HTTP/2`
 //! * `rustls` - HTTPS support via `rustls` crate, supports `HTTP/2`
 //! * `secure-cookies` - secure cookies support
 
-#![deny(rust_2018_idioms)]
+#![deny(rust_2018_idioms, nonstandard_style)]
 #![allow(clippy::needless_doctest_main, clippy::type_complexity)]
 #![doc(html_logo_url = "https://actix.rs/img/logo.png")]
 #![doc(html_favicon_url = "https://actix.rs/favicon.ico")]
 
+#[cfg(feature = "openssl")]
+extern crate tls_openssl as openssl;
+#[cfg(feature = "rustls")]
+extern crate tls_rustls as rustls;
+
 mod app;
 mod app_service;
 mod config;
@@ -81,6 +87,7 @@ mod handler;
 mod info;
 pub mod middleware;
 mod request;
+mod request_data;
 mod resource;
 mod responder;
 mod rmap;
@@ -89,11 +96,13 @@ mod scope;
 mod server;
 mod service;
 pub mod test;
-mod types;
+pub(crate) mod types;
 pub mod web;
 
+#[cfg(feature = "cookies")]
+pub use actix_http::cookie;
 pub use actix_http::Response as HttpResponse;
-pub use actix_http::{body, cookie, http, Error, HttpMessage, ResponseError, Result};
+pub use actix_http::{body, http, Error, HttpMessage, ResponseError, Result};
 pub use actix_rt as rt;
 pub use actix_web_codegen::*;
 
@@ -101,10 +110,12 @@ pub use crate::app::App;
 pub use crate::extract::FromRequest;
 pub use crate::request::HttpRequest;
 pub use crate::resource::Resource;
-pub use crate::responder::{Either, Responder};
+pub use crate::responder::Responder;
 pub use crate::route::Route;
 pub use crate::scope::Scope;
 pub use crate::server::HttpServer;
+// TODO: is exposing the error directly really needed
+pub use crate::types::{Either, EitherExtractError};
 
 pub mod dev {
     //! The `actix-web` prelude for library developers
@@ -119,12 +130,10 @@ pub mod dev {
 
     pub use crate::config::{AppConfig, AppService};
     #[doc(hidden)]
-    pub use crate::handler::Factory;
+    pub use crate::handler::Handler;
     pub use crate::info::ConnectionInfo;
     pub use crate::rmap::ResourceMap;
-    pub use crate::service::{
-        HttpServiceFactory, ServiceRequest, ServiceResponse, WebService,
-    };
+    pub use crate::service::{HttpServiceFactory, ServiceRequest, ServiceResponse, WebService};
 
     pub use crate::types::form::UrlEncoded;
     pub use crate::types::json::JsonBody;
@@ -134,9 +143,7 @@ pub mod dev {
     #[cfg(feature = "compress")]
     pub use actix_http::encoding::Decoder as Decompress;
     pub use actix_http::ResponseBuilder as HttpResponseBuilder;
-    pub use actix_http::{
-        Extensions, Payload, PayloadStream, RequestHead, ResponseHead,
-    };
+    pub use actix_http::{Extensions, Payload, PayloadStream, RequestHead, ResponseHead};
     pub use actix_router::{Path, ResourceDef, ResourcePath, Url};
     pub use actix_server::Server;
     pub use actix_service::{Service, Transform};
@@ -194,29 +201,3 @@ pub mod dev {
         }
     }
 }
-
-pub mod client {
-    //! Actix web async HTTP client.
-    //!
-    //! ```rust
-    //! use actix_web::client::Client;
-    //!
-    //! #[actix_web::main]
-    //! async fn main() {
-    //!    let mut client = Client::default();
-    //!
-    //!    // Create request builder and send request
-    //!    let response = client.get("http://www.rust-lang.org")
-    //!       .header("User-Agent", "actix-web/3.0")
-    //!       .send()     // <- Send request
-    //!       .await;     // <- Wait for response
-    //!
-    //!    println!("Response: {:?}", response);
-    //! }
-    //! ```
-
-    pub use awc::error::*;
-    pub use awc::{
-        test, Client, ClientBuilder, ClientRequest, ClientResponse, Connector,
-    };
-}
diff --git a/src/middleware/compat.rs b/src/middleware/compat.rs
new file mode 100644
index 000000000..6f60264b1
--- /dev/null
+++ b/src/middleware/compat.rs
@@ -0,0 +1,202 @@
+//! For middleware documentation, see [`Compat`].
+
+use std::{
+    future::Future,
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use actix_http::body::{Body, MessageBody, ResponseBody};
+use actix_service::{Service, Transform};
+use futures_core::{future::LocalBoxFuture, ready};
+
+use crate::{error::Error, service::ServiceResponse};
+
+/// Middleware for enabling any middleware to be used in [`Resource::wrap`](crate::Resource::wrap),
+/// [`Scope::wrap`](crate::Scope::wrap) and [`Condition`](super::Condition).
+///
+/// # Examples
+/// ```rust
+/// use actix_web::middleware::{Logger, Compat};
+/// use actix_web::{App, web};
+///
+/// let logger = Logger::default();
+///
+/// // this would not compile because of incompatible body types
+/// // let app = App::new()
+/// //     .service(web::scope("scoped").wrap(logger));
+///
+/// // by using this middleware we can use the logger on a scope
+/// let app = App::new()
+///     .service(web::scope("scoped").wrap(Compat::new(logger)));
+/// ```
+pub struct Compat<T> {
+    transform: T,
+}
+
+impl<T> Compat<T> {
+    /// Wrap a middleware to give it broader compatibility.
+    pub fn new(middleware: T) -> Self {
+        Self {
+            transform: middleware,
+        }
+    }
+}
+
+impl<S, T, Req> Transform<S, Req> for Compat<T>
+where
+    S: Service<Req>,
+    T: Transform<S, Req>,
+    T::Future: 'static,
+    T::Response: MapServiceResponseBody,
+    Error: From<T::Error>,
+{
+    type Response = ServiceResponse;
+    type Error = Error;
+    type Transform = CompatMiddleware<T::Transform>;
+    type InitError = T::InitError;
+    type Future = LocalBoxFuture<'static, Result<Self::Transform, Self::InitError>>;
+
+    fn new_transform(&self, service: S) -> Self::Future {
+        let fut = self.transform.new_transform(service);
+        Box::pin(async move {
+            let service = fut.await?;
+            Ok(CompatMiddleware { service })
+        })
+    }
+}
+
+pub struct CompatMiddleware<S> {
+    service: S,
+}
+
+impl<S, Req> Service<Req> for CompatMiddleware<S>
+where
+    S: Service<Req>,
+    S::Response: MapServiceResponseBody,
+    Error: From<S::Error>,
+{
+    type Response = ServiceResponse;
+    type Error = Error;
+    type Future = CompatMiddlewareFuture<S::Future>;
+
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        self.service.poll_ready(cx).map_err(From::from)
+    }
+
+    fn call(&self, req: Req) -> Self::Future {
+        let fut = self.service.call(req);
+        CompatMiddlewareFuture { fut }
+    }
+}
+
+#[pin_project::pin_project]
+pub struct CompatMiddlewareFuture<Fut> {
+    #[pin]
+    fut: Fut,
+}
+
+impl<Fut, T, E> Future for CompatMiddlewareFuture<Fut>
+where
+    Fut: Future<Output = Result<T, E>>,
+    T: MapServiceResponseBody,
+    Error: From<E>,
+{
+    type Output = Result<ServiceResponse, Error>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let res = ready!(self.project().fut.poll(cx))?;
+        Poll::Ready(Ok(res.map_body()))
+    }
+}
+
+/// Convert `ServiceResponse`'s `ResponseBody<B>` generic type to `ResponseBody<Body>`.
+pub trait MapServiceResponseBody {
+    fn map_body(self) -> ServiceResponse;
+}
+
+impl<B: MessageBody + Unpin + 'static> MapServiceResponseBody for ServiceResponse<B> {
+    fn map_body(self) -> ServiceResponse {
+        self.map_body(|_, body| ResponseBody::Other(Body::from_message(body)))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    // easier to code when cookies feature is disabled
+    #![allow(unused_imports)]
+
+    use super::*;
+
+    use actix_service::IntoService;
+
+    use crate::dev::ServiceRequest;
+    use crate::http::StatusCode;
+    use crate::middleware::{self, Condition, Logger};
+    use crate::test::{call_service, init_service, TestRequest};
+    use crate::{web, App, HttpResponse};
+
+    #[actix_rt::test]
+    #[cfg(feature = "cookies")]
+    async fn test_scope_middleware() {
+        use crate::middleware::Compress;
+
+        let logger = Logger::default();
+        let compress = Compress::default();
+
+        let srv = init_service(
+            App::new().service(
+                web::scope("app")
+                    .wrap(Compat::new(logger))
+                    .wrap(Compat::new(compress))
+                    .service(web::resource("/test").route(web::get().to(HttpResponse::Ok))),
+            ),
+        )
+        .await;
+
+        let req = TestRequest::with_uri("/app/test").to_request();
+        let resp = call_service(&srv, req).await;
+        assert_eq!(resp.status(), StatusCode::OK);
+    }
+
+    #[actix_rt::test]
+    #[cfg(feature = "cookies")]
+    async fn test_resource_scope_middleware() {
+        use crate::middleware::Compress;
+
+        let logger = Logger::default();
+        let compress = Compress::default();
+
+        let srv = init_service(
+            App::new().service(
+                web::resource("app/test")
+                    .wrap(Compat::new(logger))
+                    .wrap(Compat::new(compress))
+                    .route(web::get().to(HttpResponse::Ok)),
+            ),
+        )
+        .await;
+
+        let req = TestRequest::with_uri("/app/test").to_request();
+        let resp = call_service(&srv, req).await;
+        assert_eq!(resp.status(), StatusCode::OK);
+    }
+
+    #[actix_rt::test]
+    async fn test_condition_scope_middleware() {
+        let srv = |req: ServiceRequest| {
+            Box::pin(async move {
+                Ok(req.into_response(HttpResponse::InternalServerError().finish()))
+            })
+        };
+
+        let logger = Logger::default();
+
+        let mw = Condition::new(true, Compat::new(logger))
+            .new_transform(srv.into_service())
+            .await
+            .unwrap();
+        let resp = call_service(&mw, TestRequest::default().to_srv_request()).await;
+        assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR);
+    }
+}
diff --git a/src/middleware/compress.rs b/src/middleware/compress.rs
index fe3ba841c..698ba768e 100644
--- a/src/middleware/compress.rs
+++ b/src/middleware/compress.rs
@@ -1,45 +1,48 @@
-//! `Middleware` for compressing response body.
-use std::cmp;
-use std::future::Future;
-use std::marker::PhantomData;
-use std::pin::Pin;
-use std::str::FromStr;
-use std::task::{Context, Poll};
+//! For middleware documentation, see [`Compress`].
 
-use actix_http::body::MessageBody;
-use actix_http::encoding::Encoder;
-use actix_http::http::header::{ContentEncoding, ACCEPT_ENCODING};
-use actix_http::Error;
+use std::{
+    cmp,
+    future::Future,
+    marker::PhantomData,
+    pin::Pin,
+    str::FromStr,
+    task::{Context, Poll},
+};
+
+use actix_http::{
+    body::MessageBody,
+    encoding::Encoder,
+    http::header::{ContentEncoding, ACCEPT_ENCODING},
+    Error,
+};
 use actix_service::{Service, Transform};
+use futures_core::ready;
 use futures_util::future::{ok, Ready};
 use pin_project::pin_project;
 
-use crate::dev::BodyEncoding;
-use crate::service::{ServiceRequest, ServiceResponse};
+use crate::{
+    dev::BodyEncoding,
+    service::{ServiceRequest, ServiceResponse},
+};
 
-#[derive(Debug, Clone)]
-/// `Middleware` for compressing response body.
+/// Middleware for compressing response payloads.
 ///
-/// Use `BodyEncoding` trait for overriding response compression.
-/// To disable compression set encoding to `ContentEncoding::Identity` value.
+/// Use `BodyEncoding` trait for overriding response compression. To disable compression set
+/// encoding to `ContentEncoding::Identity`.
 ///
+/// # Examples
 /// ```rust
 /// use actix_web::{web, middleware, App, HttpResponse};
 ///
-/// fn main() {
-///     let app = App::new()
-///         .wrap(middleware::Compress::default())
-///         .service(
-///             web::resource("/test")
-///                 .route(web::get().to(|| HttpResponse::Ok()))
-///                 .route(web::head().to(|| HttpResponse::MethodNotAllowed()))
-///         );
-/// }
+/// let app = App::new()
+///     .wrap(middleware::Compress::default())
+///     .default_service(web::to(|| HttpResponse::NotFound()));
 /// ```
+#[derive(Debug, Clone)]
 pub struct Compress(ContentEncoding);
 
 impl Compress {
-    /// Create new `Compress` middleware with default encoding.
+    /// Create new `Compress` middleware with the specified encoding.
     pub fn new(encoding: ContentEncoding) -> Self {
         Compress(encoding)
     }
@@ -51,16 +54,15 @@ impl Default for Compress {
     }
 }
 
-impl<S, B> Transform<S> for Compress
+impl<S, B> Transform<S, ServiceRequest> for Compress
 where
     B: MessageBody,
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<Encoder<B>>;
     type Error = Error;
-    type InitError = ();
     type Transform = CompressMiddleware<S>;
+    type InitError = ();
     type Future = Ready<Result<Self::Transform, Self::InitError>>;
 
     fn new_transform(&self, service: S) -> Self::Future {
@@ -76,22 +78,19 @@ pub struct CompressMiddleware<S> {
     encoding: ContentEncoding,
 }
 
-impl<S, B> Service for CompressMiddleware<S>
+impl<S, B> Service<ServiceRequest> for CompressMiddleware<S>
 where
     B: MessageBody,
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<Encoder<B>>;
     type Error = Error;
     type Future = CompressResponse<S, B>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.service.poll_ready(cx)
-    }
+    actix_service::forward_ready!(service);
 
     #[allow(clippy::borrow_interior_mutable_const)]
-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
+    fn call(&self, req: ServiceRequest) -> Self::Future {
         // negotiate content-encoding
         let encoding = if let Some(val) = req.headers().get(&ACCEPT_ENCODING) {
             if let Ok(enc) = val.to_str() {
@@ -106,35 +105,34 @@ where
         CompressResponse {
             encoding,
             fut: self.service.call(req),
-            _t: PhantomData,
+            _phantom: PhantomData,
         }
     }
 }
 
-#[doc(hidden)]
 #[pin_project]
 pub struct CompressResponse<S, B>
 where
-    S: Service,
+    S: Service<ServiceRequest>,
     B: MessageBody,
 {
     #[pin]
     fut: S::Future,
     encoding: ContentEncoding,
-    _t: PhantomData<B>,
+    _phantom: PhantomData<B>,
 }
 
 impl<S, B> Future for CompressResponse<S, B>
 where
     B: MessageBody,
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
 {
     type Output = Result<ServiceResponse<Encoder<B>>, Error>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let this = self.project();
 
-        match futures_util::ready!(this.fut.poll(cx)) {
+        match ready!(this.fut.poll(cx)) {
             Ok(resp) => {
                 let enc = if let Some(enc) = resp.response().get_encoding() {
                     enc
@@ -192,10 +190,7 @@ impl AcceptEncoding {
         };
         let quality = match parts.len() {
             1 => encoding.quality(),
-            _ => match f64::from_str(parts[1]) {
-                Ok(q) => q,
-                Err(_) => 0.0,
-            },
+            _ => f64::from_str(parts[1]).unwrap_or(0.0),
         };
         Some(AcceptEncoding { encoding, quality })
     }
diff --git a/src/middleware/condition.rs b/src/middleware/condition.rs
index ab1c69746..f0c344062 100644
--- a/src/middleware/condition.rs
+++ b/src/middleware/condition.rs
@@ -1,63 +1,64 @@
-//! `Middleware` for conditionally enables another middleware.
+//! For middleware documentation, see [`Condition`].
+
 use std::task::{Context, Poll};
 
 use actix_service::{Service, Transform};
-use futures_util::future::{ok, Either, FutureExt, LocalBoxFuture};
+use futures_util::future::{Either, FutureExt, LocalBoxFuture};
 
-/// `Middleware` for conditionally enables another middleware.
-/// The controlled middleware must not change the `Service` interfaces.
-/// This means you cannot control such middlewares like `Logger` or `Compress`.
+/// Middleware for conditionally enabling other middleware.
 ///
-/// ## Usage
+/// The controlled middleware must not change the `Service` interfaces. This means you cannot
+/// control such middlewares like `Logger` or `Compress` directly. See the [`Compat`](super::Compat)
+/// middleware for a workaround.
 ///
+/// # Examples
 /// ```rust
 /// use actix_web::middleware::{Condition, NormalizePath};
 /// use actix_web::App;
 ///
-/// # fn main() {
-/// let enable_normalize = std::env::var("NORMALIZE_PATH") == Ok("true".into());
+/// let enable_normalize = std::env::var("NORMALIZE_PATH").is_ok();
 /// let app = App::new()
 ///     .wrap(Condition::new(enable_normalize, NormalizePath::default()));
-/// # }
 /// ```
 pub struct Condition<T> {
-    trans: T,
+    transformer: T,
     enable: bool,
 }
 
 impl<T> Condition<T> {
-    pub fn new(enable: bool, trans: T) -> Self {
-        Self { trans, enable }
+    pub fn new(enable: bool, transformer: T) -> Self {
+        Self {
+            transformer,
+            enable,
+        }
     }
 }
 
-impl<S, T> Transform<S> for Condition<T>
+impl<S, T, Req> Transform<S, Req> for Condition<T>
 where
-    S: Service + 'static,
-    T: Transform<S, Request = S::Request, Response = S::Response, Error = S::Error>,
+    S: Service<Req> + 'static,
+    T: Transform<S, Req, Response = S::Response, Error = S::Error>,
     T::Future: 'static,
     T::InitError: 'static,
     T::Transform: 'static,
 {
-    type Request = S::Request;
     type Response = S::Response;
     type Error = S::Error;
-    type InitError = T::InitError;
     type Transform = ConditionMiddleware<T::Transform, S>;
+    type InitError = T::InitError;
     type Future = LocalBoxFuture<'static, Result<Self::Transform, Self::InitError>>;
 
     fn new_transform(&self, service: S) -> Self::Future {
         if self.enable {
-            let f = self.trans.new_transform(service).map(|res| {
-                res.map(
-                    ConditionMiddleware::Enable as fn(T::Transform) -> Self::Transform,
-                )
-            });
-            Either::Left(f)
+            let fut = self.transformer.new_transform(service);
+            async move {
+                let wrapped_svc = fut.await?;
+                Ok(ConditionMiddleware::Enable(wrapped_svc))
+            }
+            .boxed_local()
         } else {
-            Either::Right(ok(ConditionMiddleware::Disable(service)))
+            async move { Ok(ConditionMiddleware::Disable(service)) }.boxed_local()
         }
-        .boxed_local()
     }
 }
 
@@ -66,29 +67,26 @@ pub enum ConditionMiddleware<E, D> {
     Disable(D),
 }
 
-impl<E, D> Service for ConditionMiddleware<E, D>
+impl<E, D, Req> Service<Req> for ConditionMiddleware<E, D>
 where
-    E: Service,
-    D: Service<Request = E::Request, Response = E::Response, Error = E::Error>,
+    E: Service<Req>,
+    D: Service<Req, Response = E::Response, Error = E::Error>,
 {
-    type Request = E::Request;
     type Response = E::Response;
     type Error = E::Error;
     type Future = Either<E::Future, D::Future>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        use ConditionMiddleware::*;
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         match self {
-            Enable(service) => service.poll_ready(cx),
-            Disable(service) => service.poll_ready(cx),
+            ConditionMiddleware::Enable(service) => service.poll_ready(cx),
+            ConditionMiddleware::Disable(service) => service.poll_ready(cx),
         }
     }
 
-    fn call(&mut self, req: E::Request) -> Self::Future {
-        use ConditionMiddleware::*;
+    fn call(&self, req: Req) -> Self::Future {
         match self {
-            Enable(service) => Either::Left(service.call(req)),
-            Disable(service) => Either::Right(service.call(req)),
+            ConditionMiddleware::Enable(service) => Either::Left(service.call(req)),
+            ConditionMiddleware::Disable(service) => Either::Right(service.call(req)),
         }
     }
 }
@@ -96,14 +94,17 @@ where
 #[cfg(test)]
 mod tests {
     use actix_service::IntoService;
+    use futures_util::future::ok;
 
     use super::*;
-    use crate::dev::{ServiceRequest, ServiceResponse};
-    use crate::error::Result;
-    use crate::http::{header::CONTENT_TYPE, HeaderValue, StatusCode};
-    use crate::middleware::errhandlers::*;
-    use crate::test::{self, TestRequest};
-    use crate::HttpResponse;
+    use crate::{
+        dev::{ServiceRequest, ServiceResponse},
+        error::Result,
+        http::{header::CONTENT_TYPE, HeaderValue, StatusCode},
+        middleware::err_handlers::*,
+        test::{self, TestRequest},
+        HttpResponse,
+    };
 
     fn render_500<B>(mut res: ServiceResponse<B>) -> Result<ErrorHandlerResponse<B>> {
         res.response_mut()
@@ -118,15 +119,13 @@ mod tests {
             ok(req.into_response(HttpResponse::InternalServerError().finish()))
         };
 
-        let mw =
-            ErrorHandlers::new().handler(StatusCode::INTERNAL_SERVER_ERROR, render_500);
+        let mw = ErrorHandlers::new().handler(StatusCode::INTERNAL_SERVER_ERROR, render_500);
 
-        let mut mw = Condition::new(true, mw)
+        let mw = Condition::new(true, mw)
             .new_transform(srv.into_service())
             .await
             .unwrap();
-        let resp =
-            test::call_service(&mut mw, TestRequest::default().to_srv_request()).await;
+        let resp = test::call_service(&mw, TestRequest::default().to_srv_request()).await;
         assert_eq!(resp.headers().get(CONTENT_TYPE).unwrap(), "0001");
     }
 
@@ -136,16 +135,14 @@ mod tests {
             ok(req.into_response(HttpResponse::InternalServerError().finish()))
         };
 
-        let mw =
-            ErrorHandlers::new().handler(StatusCode::INTERNAL_SERVER_ERROR, render_500);
+        let mw = ErrorHandlers::new().handler(StatusCode::INTERNAL_SERVER_ERROR, render_500);
 
-        let mut mw = Condition::new(false, mw)
+        let mw = Condition::new(false, mw)
             .new_transform(srv.into_service())
             .await
             .unwrap();
 
-        let resp =
-            test::call_service(&mut mw, TestRequest::default().to_srv_request()).await;
+        let resp = test::call_service(&mw, TestRequest::default().to_srv_request()).await;
         assert_eq!(resp.headers().get(CONTENT_TYPE), None);
     }
 }
diff --git a/src/middleware/defaultheaders.rs b/src/middleware/default_headers.rs
similarity index 54%
rename from src/middleware/defaultheaders.rs
rename to src/middleware/default_headers.rs
index 6d43aba95..a36cc2f29 100644
--- a/src/middleware/defaultheaders.rs
+++ b/src/middleware/default_headers.rs
@@ -1,20 +1,34 @@
-//! Middleware for setting default response headers
-use std::convert::TryFrom;
-use std::rc::Rc;
-use std::task::{Context, Poll};
+//! For middleware documentation, see [`DefaultHeaders`].
 
-use actix_service::{Service, Transform};
-use futures_util::future::{ok, FutureExt, LocalBoxFuture, Ready};
+use std::{
+    convert::TryFrom,
+    future::Future,
+    marker::PhantomData,
+    pin::Pin,
+    rc::Rc,
+    task::{Context, Poll},
+};
 
-use crate::http::header::{HeaderName, HeaderValue, CONTENT_TYPE};
-use crate::http::{Error as HttpError, HeaderMap};
-use crate::service::{ServiceRequest, ServiceResponse};
-use crate::Error;
+use futures_util::{
+    future::{ready, Ready},
+    ready,
+};
 
-/// `Middleware` for setting default response headers.
+use crate::{
+    dev::{Service, Transform},
+    http::{
+        header::{HeaderName, HeaderValue, CONTENT_TYPE},
+        Error as HttpError, HeaderMap,
+    },
+    service::{ServiceRequest, ServiceResponse},
+    Error,
+};
+
+/// Middleware for setting default response headers.
 ///
-/// This middleware does not set header if response headers already contains it.
+/// Headers with the same key that are already set in a response will *not* be overwritten.
 ///
+/// # Examples
 /// ```rust
 /// use actix_web::{web, http, middleware, App, HttpResponse};
 ///
@@ -34,7 +48,6 @@ pub struct DefaultHeaders {
 }
 
 struct Inner {
-    ct: bool,
     headers: HeaderMap,
 }
 
@@ -42,7 +55,6 @@ impl Default for DefaultHeaders {
     fn default() -> Self {
         DefaultHeaders {
             inner: Rc::new(Inner {
-                ct: false,
                 headers: HeaderMap::new(),
             }),
         }
@@ -50,12 +62,12 @@ impl Default for DefaultHeaders {
 }
 
 impl DefaultHeaders {
-    /// Construct `DefaultHeaders` middleware.
+    /// Constructs an empty `DefaultHeaders` middleware.
     pub fn new() -> DefaultHeaders {
         DefaultHeaders::default()
     }
 
-    /// Set a header.
+    /// Adds a header to the default set.
     #[inline]
     pub fn header<K, V>(mut self, key: K, value: V) -> Self
     where
@@ -80,32 +92,38 @@ impl DefaultHeaders {
         self
     }
 
-    /// Set *CONTENT-TYPE* header if response does not contain this header.
-    pub fn content_type(mut self) -> Self {
+    /// Adds a default *Content-Type* header if response does not contain one.
+    ///
+    /// Default is `application/octet-stream`.
+    pub fn add_content_type(mut self) -> Self {
         Rc::get_mut(&mut self.inner)
-            .expect("Multiple copies exist")
-            .ct = true;
+            .expect("Multiple `Inner` copies exist.")
+            .headers
+            .insert(
+                CONTENT_TYPE,
+                HeaderValue::from_static("application/octet-stream"),
+            );
+
         self
     }
 }
 
-impl<S, B> Transform<S> for DefaultHeaders
+impl<S, B> Transform<S, ServiceRequest> for DefaultHeaders
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
     S::Future: 'static,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<B>;
     type Error = Error;
-    type InitError = ();
     type Transform = DefaultHeadersMiddleware<S>;
+    type InitError = ();
     type Future = Ready<Result<Self::Transform, Self::InitError>>;
 
     fn new_transform(&self, service: S) -> Self::Future {
-        ok(DefaultHeadersMiddleware {
+        ready(Ok(DefaultHeadersMiddleware {
             service,
             inner: self.inner.clone(),
-        })
+        }))
     }
 }
 
@@ -114,44 +132,56 @@ pub struct DefaultHeadersMiddleware<S> {
     inner: Rc<Inner>,
 }
 
-impl<S, B> Service for DefaultHeadersMiddleware<S>
+impl<S, B> Service<ServiceRequest> for DefaultHeadersMiddleware<S>
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
     S::Future: 'static,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<B>;
     type Error = Error;
-    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
+    type Future = DefaultHeaderFuture<S, B>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.service.poll_ready(cx)
-    }
+    actix_service::forward_ready!(service);
 
-    #[allow(clippy::borrow_interior_mutable_const)]
-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
+    fn call(&self, req: ServiceRequest) -> Self::Future {
         let inner = self.inner.clone();
         let fut = self.service.call(req);
 
-        async move {
-            let mut res = fut.await?;
-
-            // set response headers
-            for (key, value) in inner.headers.iter() {
-                if !res.headers().contains_key(key) {
-                    res.headers_mut().insert(key.clone(), value.clone());
-                }
-            }
-            // default content-type
-            if inner.ct && !res.headers().contains_key(&CONTENT_TYPE) {
-                res.headers_mut().insert(
-                    CONTENT_TYPE,
-                    HeaderValue::from_static("application/octet-stream"),
-                );
-            }
-            Ok(res)
+        DefaultHeaderFuture {
+            fut,
+            inner,
+            _body: PhantomData,
         }
-        .boxed_local()
+    }
+}
+
+#[pin_project::pin_project]
+pub struct DefaultHeaderFuture<S: Service<ServiceRequest>, B> {
+    #[pin]
+    fut: S::Future,
+    inner: Rc<Inner>,
+    _body: PhantomData<B>,
+}
+
+impl<S, B> Future for DefaultHeaderFuture<S, B>
+where
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+{
+    type Output = <S::Future as Future>::Output;
+
+    #[allow(clippy::borrow_interior_mutable_const)]
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.project();
+        let mut res = ready!(this.fut.poll(cx))?;
+
+        // set response headers
+        for (key, value) in this.inner.headers.iter() {
+            if !res.headers().contains_key(key) {
+                res.headers_mut().insert(key.clone(), value.clone());
+            }
+        }
+
+        Poll::Ready(Ok(res))
     }
 }
 
@@ -161,14 +191,16 @@ mod tests {
     use futures_util::future::ok;
 
     use super::*;
-    use crate::dev::ServiceRequest;
-    use crate::http::header::CONTENT_TYPE;
-    use crate::test::{ok_service, TestRequest};
-    use crate::HttpResponse;
+    use crate::{
+        dev::ServiceRequest,
+        http::header::CONTENT_TYPE,
+        test::{ok_service, TestRequest},
+        HttpResponse,
+    };
 
     #[actix_rt::test]
     async fn test_default_headers() {
-        let mut mw = DefaultHeaders::new()
+        let mw = DefaultHeaders::new()
             .header(CONTENT_TYPE, "0001")
             .new_transform(ok_service())
             .await
@@ -180,10 +212,13 @@ mod tests {
 
         let req = TestRequest::default().to_srv_request();
         let srv = |req: ServiceRequest| {
-            ok(req
-                .into_response(HttpResponse::Ok().header(CONTENT_TYPE, "0002").finish()))
+            ok(req.into_response(
+                HttpResponse::Ok()
+                    .insert_header((CONTENT_TYPE, "0002"))
+                    .finish(),
+            ))
         };
-        let mut mw = DefaultHeaders::new()
+        let mw = DefaultHeaders::new()
             .header(CONTENT_TYPE, "0001")
             .new_transform(srv.into_service())
             .await
@@ -194,10 +229,9 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_content_type() {
-        let srv =
-            |req: ServiceRequest| ok(req.into_response(HttpResponse::Ok().finish()));
-        let mut mw = DefaultHeaders::new()
-            .content_type()
+        let srv = |req: ServiceRequest| ok(req.into_response(HttpResponse::Ok().finish()));
+        let mw = DefaultHeaders::new()
+            .add_content_type()
             .new_transform(srv.into_service())
             .await
             .unwrap();
diff --git a/src/middleware/errhandlers.rs b/src/middleware/err_handlers.rs
similarity index 53%
rename from src/middleware/errhandlers.rs
rename to src/middleware/err_handlers.rs
index 93a5d3f22..4673ed4ce 100644
--- a/src/middleware/errhandlers.rs
+++ b/src/middleware/err_handlers.rs
@@ -1,35 +1,41 @@
-//! Custom handlers service for responses.
-use std::rc::Rc;
-use std::task::{Context, Poll};
+//! For middleware documentation, see [`ErrorHandlers`].
+
+use std::{
+    future::Future,
+    pin::Pin,
+    rc::Rc,
+    task::{Context, Poll},
+};
 
 use actix_service::{Service, Transform};
-use futures_util::future::{ok, FutureExt, LocalBoxFuture, Ready};
-use fxhash::FxHashMap;
+use ahash::AHashMap;
+use futures_core::{future::LocalBoxFuture, ready};
 
-use crate::dev::{ServiceRequest, ServiceResponse};
-use crate::error::{Error, Result};
-use crate::http::StatusCode;
+use crate::{
+    dev::{ServiceRequest, ServiceResponse},
+    error::{Error, Result},
+    http::StatusCode,
+};
 
-/// Error handler response
+/// Return type for [`ErrorHandlers`] custom handlers.
 pub enum ErrorHandlerResponse<B> {
-    /// New http response got generated
+    /// Immediate HTTP response.
     Response(ServiceResponse<B>),
-    /// Result is a future that resolves to a new http response
+
+    /// A future that resolves to an HTTP response.
     Future(LocalBoxFuture<'static, Result<ServiceResponse<B>, Error>>),
 }
 
 type ErrorHandler<B> = dyn Fn(ServiceResponse<B>) -> Result<ErrorHandlerResponse<B>>;
 
-/// `Middleware` for allowing custom handlers for responses.
+/// Middleware for registering custom status code based error handlers.
 ///
-/// You can use `ErrorHandlers::handler()` method  to register a custom error
-/// handler for specific status code. You can modify existing response or
-/// create completely new one.
-///
-/// ## Example
+/// Register handlers with the `ErrorHandlers::handler()` method to register a custom error handler
+/// for a given status code. Handlers can modify existing responses or create completely new ones.
 ///
+/// # Examples
 /// ```rust
-/// use actix_web::middleware::errhandlers::{ErrorHandlers, ErrorHandlerResponse};
+/// use actix_web::middleware::{ErrorHandlers, ErrorHandlerResponse};
 /// use actix_web::{web, http, dev, App, HttpRequest, HttpResponse, Result};
 ///
 /// fn render_500<B>(mut res: dev::ServiceResponse<B>) -> Result<ErrorHandlerResponse<B>> {
@@ -39,7 +45,6 @@ type ErrorHandler<B> = dyn Fn(ServiceResponse<B>) -> Result<ErrorHandlerResponse
 ///     Ok(ErrorHandlerResponse::Response(res))
 /// }
 ///
-/// # fn main() {
 /// let app = App::new()
 ///     .wrap(
 ///         ErrorHandlers::new()
@@ -49,27 +54,28 @@ type ErrorHandler<B> = dyn Fn(ServiceResponse<B>) -> Result<ErrorHandlerResponse
 ///         .route(web::get().to(|| HttpResponse::Ok()))
 ///         .route(web::head().to(|| HttpResponse::MethodNotAllowed())
 ///     ));
-/// # }
 /// ```
 pub struct ErrorHandlers<B> {
-    handlers: Rc<FxHashMap<StatusCode, Box<ErrorHandler<B>>>>,
+    handlers: Handlers<B>,
 }
 
+type Handlers<B> = Rc<AHashMap<StatusCode, Box<ErrorHandler<B>>>>;
+
 impl<B> Default for ErrorHandlers<B> {
     fn default() -> Self {
         ErrorHandlers {
-            handlers: Rc::new(FxHashMap::default()),
+            handlers: Rc::new(AHashMap::default()),
         }
     }
 }
 
 impl<B> ErrorHandlers<B> {
-    /// Construct new `ErrorHandlers` instance
+    /// Construct new `ErrorHandlers` instance.
     pub fn new() -> Self {
         ErrorHandlers::default()
     }
 
-    /// Register error handler for specified status code
+    /// Register error handler for specified status code.
     pub fn handler<F>(mut self, status: StatusCode, handler: F) -> Self
     where
         F: Fn(ServiceResponse<B>) -> Result<ErrorHandlerResponse<B>> + 'static,
@@ -81,73 +87,95 @@ impl<B> ErrorHandlers<B> {
     }
 }
 
-impl<S, B> Transform<S> for ErrorHandlers<B>
+impl<S, B> Transform<S, ServiceRequest> for ErrorHandlers<B>
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error> + 'static,
     S::Future: 'static,
     B: 'static,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<B>;
     type Error = Error;
-    type InitError = ();
     type Transform = ErrorHandlersMiddleware<S, B>;
-    type Future = Ready<Result<Self::Transform, Self::InitError>>;
+    type InitError = ();
+    type Future = LocalBoxFuture<'static, Result<Self::Transform, Self::InitError>>;
 
     fn new_transform(&self, service: S) -> Self::Future {
-        ok(ErrorHandlersMiddleware {
-            service,
-            handlers: self.handlers.clone(),
-        })
+        let handlers = self.handlers.clone();
+        Box::pin(async move { Ok(ErrorHandlersMiddleware { service, handlers }) })
     }
 }
 
 #[doc(hidden)]
 pub struct ErrorHandlersMiddleware<S, B> {
     service: S,
-    handlers: Rc<FxHashMap<StatusCode, Box<ErrorHandler<B>>>>,
+    handlers: Handlers<B>,
 }
 
-impl<S, B> Service for ErrorHandlersMiddleware<S, B>
+impl<S, B> Service<ServiceRequest> for ErrorHandlersMiddleware<S, B>
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
     S::Future: 'static,
     B: 'static,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<B>;
     type Error = Error;
-    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
+    type Future = ErrorHandlersFuture<S::Future, B>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.service.poll_ready(cx)
-    }
+    actix_service::forward_ready!(service);
 
-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
+    fn call(&self, req: ServiceRequest) -> Self::Future {
         let handlers = self.handlers.clone();
         let fut = self.service.call(req);
+        ErrorHandlersFuture::ServiceFuture { fut, handlers }
+    }
+}
 
-        async move {
-            let res = fut.await?;
+#[pin_project::pin_project(project = ErrorHandlersProj)]
+pub enum ErrorHandlersFuture<Fut, B>
+where
+    Fut: Future,
+{
+    ServiceFuture {
+        #[pin]
+        fut: Fut,
+        handlers: Handlers<B>,
+    },
+    HandlerFuture {
+        fut: LocalBoxFuture<'static, Fut::Output>,
+    },
+}
 
-            if let Some(handler) = handlers.get(&res.status()) {
-                match handler(res) {
-                    Ok(ErrorHandlerResponse::Response(res)) => Ok(res),
-                    Ok(ErrorHandlerResponse::Future(fut)) => fut.await,
-                    Err(e) => Err(e),
+impl<Fut, B> Future for ErrorHandlersFuture<Fut, B>
+where
+    Fut: Future<Output = Result<ServiceResponse<B>, Error>>,
+{
+    type Output = Fut::Output;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        match self.as_mut().project() {
+            ErrorHandlersProj::ServiceFuture { fut, handlers } => {
+                let res = ready!(fut.poll(cx))?;
+                match handlers.get(&res.status()) {
+                    Some(handler) => match handler(res)? {
+                        ErrorHandlerResponse::Response(res) => Poll::Ready(Ok(res)),
+                        ErrorHandlerResponse::Future(fut) => {
+                            self.as_mut()
+                                .set(ErrorHandlersFuture::HandlerFuture { fut });
+                            self.poll(cx)
+                        }
+                    },
+                    None => Poll::Ready(Ok(res)),
                 }
-            } else {
-                Ok(res)
             }
+            ErrorHandlersProj::HandlerFuture { fut } => fut.as_mut().poll(cx),
         }
-        .boxed_local()
     }
 }
 
 #[cfg(test)]
 mod tests {
     use actix_service::IntoService;
-    use futures_util::future::ok;
+    use futures_util::future::{ok, FutureExt};
 
     use super::*;
     use crate::http::{header::CONTENT_TYPE, HeaderValue, StatusCode};
@@ -167,14 +195,13 @@ mod tests {
             ok(req.into_response(HttpResponse::InternalServerError().finish()))
         };
 
-        let mut mw = ErrorHandlers::new()
+        let mw = ErrorHandlers::new()
             .handler(StatusCode::INTERNAL_SERVER_ERROR, render_500)
             .new_transform(srv.into_service())
             .await
             .unwrap();
 
-        let resp =
-            test::call_service(&mut mw, TestRequest::default().to_srv_request()).await;
+        let resp = test::call_service(&mw, TestRequest::default().to_srv_request()).await;
         assert_eq!(resp.headers().get(CONTENT_TYPE).unwrap(), "0001");
     }
 
@@ -193,14 +220,13 @@ mod tests {
             ok(req.into_response(HttpResponse::InternalServerError().finish()))
         };
 
-        let mut mw = ErrorHandlers::new()
+        let mw = ErrorHandlers::new()
             .handler(StatusCode::INTERNAL_SERVER_ERROR, render_500_async)
             .new_transform(srv.into_service())
             .await
             .unwrap();
 
-        let resp =
-            test::call_service(&mut mw, TestRequest::default().to_srv_request()).await;
+        let resp = test::call_service(&mw, TestRequest::default().to_srv_request()).await;
         assert_eq!(resp.headers().get(CONTENT_TYPE).unwrap(), "0001");
     }
 }
diff --git a/src/middleware/logger.rs b/src/middleware/logger.rs
index 51d4722d7..5b5b5577c 100644
--- a/src/middleware/logger.rs
+++ b/src/middleware/logger.rs
@@ -1,97 +1,91 @@
-//! Request logging middleware
-use std::collections::HashSet;
-use std::convert::TryFrom;
-use std::env;
-use std::fmt::{self, Display, Formatter};
-use std::future::Future;
-use std::marker::PhantomData;
-use std::pin::Pin;
-use std::rc::Rc;
-use std::task::{Context, Poll};
+//! For middleware documentation, see [`Logger`].
+
+use std::{
+    collections::HashSet,
+    convert::TryFrom,
+    env,
+    fmt::{self, Display as _},
+    future::Future,
+    marker::PhantomData,
+    pin::Pin,
+    rc::Rc,
+    task::{Context, Poll},
+};
 
 use actix_service::{Service, Transform};
 use bytes::Bytes;
 use futures_util::future::{ok, Ready};
-use log::debug;
-use regex::Regex;
+use log::{debug, warn};
+use regex::{Regex, RegexSet};
 use time::OffsetDateTime;
 
-use crate::dev::{BodySize, MessageBody, ResponseBody};
-use crate::error::{Error, Result};
-use crate::http::{HeaderName, StatusCode};
-use crate::service::{ServiceRequest, ServiceResponse};
-use crate::HttpResponse;
+use crate::{
+    dev::{BodySize, MessageBody, ResponseBody},
+    error::{Error, Result},
+    http::{HeaderName, StatusCode},
+    service::{ServiceRequest, ServiceResponse},
+    HttpResponse,
+};
 
-/// `Middleware` for logging request and response info to the terminal.
+/// Middleware for logging request and response summaries to the terminal.
 ///
-/// `Logger` middleware uses standard log crate to log information. You should
-/// enable logger for `actix_web` package to see access log.
-/// ([`env_logger`](https://docs.rs/env_logger/*/env_logger/) or similar)
+/// This middleware uses the `log` crate to output information. Enable `log`'s output for the
+/// "actix_web" scope using [`env_logger`](https://docs.rs/env_logger) or similar crate.
 ///
-/// ## Usage
+/// # Default Format
+/// The [`default`](Logger::default) Logger uses the following format:
 ///
-/// Create `Logger` middleware with the specified `format`.
-/// Default `Logger` could be created with `default` method, it uses the
-/// default format:
+/// ```plain
+/// %a "%r" %s %b "%{Referer}i" "%{User-Agent}i" %T
 ///
-/// ```ignore
-///  %a "%r" %s %b "%{Referer}i" "%{User-Agent}i" %T
+/// Example Output:
+/// 127.0.0.1:54278 "GET /test HTTP/1.1" 404 20 "-" "HTTPie/2.2.0" 0.001074
 /// ```
+///
+/// # Examples
 /// ```rust
-/// use actix_web::middleware::Logger;
-/// use actix_web::App;
+/// use actix_web::{middleware::Logger, App};
 ///
-/// fn main() {
-///     std::env::set_var("RUST_LOG", "actix_web=info");
-///     env_logger::init();
+/// // access logs are printed with the INFO level so ensure it is enabled by default
+/// env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
 ///
-///     let app = App::new()
-///         .wrap(Logger::default())
-///         .wrap(Logger::new("%a %{User-Agent}i"));
-/// }
+/// let app = App::new()
+///     // .wrap(Logger::default())
+///     .wrap(Logger::new("%a %{User-Agent}i"));
 /// ```
 ///
-/// ## Format
-///
-/// `%%`  The percent sign
-///
-/// `%a`  Remote IP-address (IP-address of proxy if using reverse proxy)
-///
-/// `%t`  Time when the request was started to process (in rfc3339 format)
-///
-/// `%r`  First line of request
-///
-/// `%s`  Response status code
-///
-/// `%b`  Size of response in bytes, including HTTP headers
-///
-/// `%T` Time taken to serve the request, in seconds with floating fraction in
-/// .06f format
-///
-/// `%D`  Time taken to serve the request, in milliseconds
-///
-/// `%U`  Request URL
-///
-/// `%{r}a`  Real IP remote address **\***
-///
-/// `%{FOO}i`  request.headers['FOO']
-///
-/// `%{FOO}o`  response.headers['FOO']
-///
-/// `%{FOO}e`  os.environ['FOO']
+/// # Format
+/// Variable | Description
+/// -------- | -----------
+/// `%%` | The percent sign
+/// `%a` | Peer IP address (or IP address of reverse proxy if used)
+/// `%t` | Time when the request started processing (in RFC 3339 format)
+/// `%r` | First line of request (Example: `GET /test HTTP/1.1`)
+/// `%s` | Response status code
+/// `%b` | Size of response in bytes, including HTTP headers
+/// `%T` | Time taken to serve the request, in seconds to 6 decimal places
+/// `%D` | Time taken to serve the request, in milliseconds
+/// `%U` | Request URL
+/// `%{r}a` | "Real IP" remote address **\***
+/// `%{FOO}i` |  `request.headers["FOO"]`
+/// `%{FOO}o` | `response.headers["FOO"]`
+/// `%{FOO}e` | `env_var["FOO"]`
+/// `%{FOO}xi` | [Custom request replacement](Logger::custom_request_replace) labelled "FOO"
 ///
 /// # Security
-///  **\*** It is calculated using
-///  [`ConnectionInfo::realip_remote_addr()`](../dev/struct.ConnectionInfo.html#method.realip_remote_addr)
-///
-///  If you use this value ensure that all requests come from trusted hosts, since it is trivial
-///  for the remote client to simulate being another client.
+/// **\*** "Real IP" remote address is calculated using
+/// [`ConnectionInfo::realip_remote_addr()`](crate::dev::ConnectionInfo::realip_remote_addr())
 ///
+/// If you use this value, ensure that all requests come from trusted hosts. Otherwise, it is
+/// trivial for the remote client to falsify their source IP address.
+#[derive(Debug)]
 pub struct Logger(Rc<Inner>);
 
+#[derive(Debug, Clone)]
 struct Inner {
     format: Format,
     exclude: HashSet<String>,
+    exclude_regex: RegexSet,
 }
 
 impl Logger {
@@ -100,6 +94,7 @@ impl Logger {
         Logger(Rc::new(Inner {
             format: Format::new(format),
             exclude: HashSet::new(),
+            exclude_regex: RegexSet::empty(),
         }))
     }
 
@@ -111,28 +106,78 @@ impl Logger {
             .insert(path.into());
         self
     }
+
+    /// Ignore and do not log access info for paths that match regex.
+    pub fn exclude_regex<T: Into<String>>(mut self, path: T) -> Self {
+        let inner = Rc::get_mut(&mut self.0).unwrap();
+        let mut patterns = inner.exclude_regex.patterns().to_vec();
+        patterns.push(path.into());
+        let regex_set = RegexSet::new(patterns).unwrap();
+        inner.exclude_regex = regex_set;
+        self
+    }
+
+    /// Register a function that receives a ServiceRequest and returns a String for use in the
+    /// log line. The label passed as the first argument should match a replacement substring in
+    /// the logger format like `%{label}xi`.
+    ///
+    /// It is convention to print "-" to indicate no output instead of an empty string.
+    ///
+    /// # Example
+    /// ```rust
+    /// # use actix_web::{http::HeaderValue, middleware::Logger};
+    /// # fn parse_jwt_id (_req: Option<&HeaderValue>) -> String { "jwt_uid".to_owned() }
+    /// Logger::new("example %{JWT_ID}xi")
+    ///     .custom_request_replace("JWT_ID", |req| parse_jwt_id(req.headers().get("Authorization")));
+    /// ```
+    pub fn custom_request_replace(
+        mut self,
+        label: &str,
+        f: impl Fn(&ServiceRequest) -> String + 'static,
+    ) -> Self {
+        let inner = Rc::get_mut(&mut self.0).unwrap();
+
+        let ft = inner.format.0.iter_mut().find(
+            |ft| matches!(ft, FormatText::CustomRequest(unit_label, _) if label == unit_label),
+        );
+
+        if let Some(FormatText::CustomRequest(_, request_fn)) = ft {
+            // replace into None or previously registered fn using same label
+            request_fn.replace(CustomRequestFn {
+                inner_fn: Rc::new(f),
+            });
+        } else {
+            // non-printed request replacement function diagnostic
+            debug!(
+                "Attempted to register custom request logging function for nonexistent label: {}",
+                label
+            );
+        }
+
+        self
+    }
 }
 
 impl Default for Logger {
     /// Create `Logger` middleware with format:
     ///
-    /// ```ignore
+    /// ```plain
     /// %a "%r" %s %b "%{Referer}i" "%{User-Agent}i" %T
     /// ```
     fn default() -> Logger {
         Logger(Rc::new(Inner {
             format: Format::default(),
             exclude: HashSet::new(),
+            exclude_regex: RegexSet::empty(),
         }))
     }
 }
 
-impl<S, B> Transform<S> for Logger
+impl<S, B> Transform<S, ServiceRequest> for Logger
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
     B: MessageBody,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<StreamLog<B>>;
     type Error = Error;
     type InitError = ();
@@ -140,6 +185,16 @@ where
     type Future = Ready<Result<Self::Transform, Self::InitError>>;
 
     fn new_transform(&self, service: S) -> Self::Future {
+        for unit in &self.0.format.0 {
+            // missing request replacement function diagnostic
+            if let FormatText::CustomRequest(label, None) = unit {
+                warn!(
+                    "No custom request replacement function was registered for label \"{}\".",
+                    label
+                );
+            }
+        }
+
         ok(LoggerMiddleware {
             service,
             inner: self.0.clone(),
@@ -147,33 +202,32 @@ where
     }
 }
 
-/// Logger middleware
+/// Logger middleware service.
 pub struct LoggerMiddleware<S> {
     inner: Rc<Inner>,
     service: S,
 }
 
-impl<S, B> Service for LoggerMiddleware<S>
+impl<S, B> Service<ServiceRequest> for LoggerMiddleware<S>
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
     B: MessageBody,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<StreamLog<B>>;
     type Error = Error;
     type Future = LoggerResponse<S, B>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.service.poll_ready(cx)
-    }
+    actix_service::forward_ready!(service);
 
-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
-        if self.inner.exclude.contains(req.path()) {
+    fn call(&self, req: ServiceRequest) -> Self::Future {
+        if self.inner.exclude.contains(req.path())
+            || self.inner.exclude_regex.is_match(req.path())
+        {
             LoggerResponse {
                 fut: self.service.call(req),
                 format: None,
                 time: OffsetDateTime::now_utc(),
-                _t: PhantomData,
+                _phantom: PhantomData,
             }
         } else {
             let now = OffsetDateTime::now_utc();
@@ -186,30 +240,29 @@ where
                 fut: self.service.call(req),
                 format: Some(format),
                 time: now,
-                _t: PhantomData,
+                _phantom: PhantomData,
             }
         }
     }
 }
 
-#[doc(hidden)]
 #[pin_project::pin_project]
 pub struct LoggerResponse<S, B>
 where
     B: MessageBody,
-    S: Service,
+    S: Service<ServiceRequest>,
 {
     #[pin]
     fut: S::Future,
     time: OffsetDateTime,
     format: Option<Format>,
-    _t: PhantomData<(B,)>,
+    _phantom: PhantomData<B>,
 }
 
 impl<S, B> Future for LoggerResponse<S, B>
 where
     B: MessageBody,
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
 {
     type Output = Result<ServiceResponse<StreamLog<B>>, Error>;
 
@@ -262,7 +315,7 @@ pub struct StreamLog<B> {
 impl<B> PinnedDrop for StreamLog<B> {
     fn drop(self: Pin<&mut Self>) {
         if let Some(ref format) = self.format {
-            let render = |fmt: &mut Formatter<'_>| {
+            let render = |fmt: &mut fmt::Formatter<'_>| {
                 for unit in &format.0 {
                     unit.render(fmt, self.size, self.time)?;
                 }
@@ -293,10 +346,8 @@ impl<B: MessageBody> MessageBody for StreamLog<B> {
     }
 }
 
-/// A formatting style for the `Logger`, consisting of multiple
-/// `FormatText`s concatenated into one line.
-#[derive(Clone)]
-#[doc(hidden)]
+/// A formatting style for the `Logger` consisting of multiple concatenated `FormatText` items.
+#[derive(Debug, Clone)]
 struct Format(Vec<FormatText>);
 
 impl Default for Format {
@@ -312,7 +363,7 @@ impl Format {
     /// Returns `None` if the format string syntax is incorrect.
     pub fn new(s: &str) -> Format {
         log::trace!("Access log format: {}", s);
-        let fmt = Regex::new(r"%(\{([A-Za-z0-9\-_]+)\}([aioe])|[atPrUsbTD]?)").unwrap();
+        let fmt = Regex::new(r"%(\{([A-Za-z0-9\-_]+)\}([aioe]|xi)|[atPrUsbTD]?)").unwrap();
 
         let mut idx = 0;
         let mut results = Vec::new();
@@ -333,13 +384,14 @@ impl Format {
                             unreachable!()
                         }
                     }
-                    "i" => FormatText::RequestHeader(
-                        HeaderName::try_from(key.as_str()).unwrap(),
-                    ),
-                    "o" => FormatText::ResponseHeader(
-                        HeaderName::try_from(key.as_str()).unwrap(),
-                    ),
+                    "i" => {
+                        FormatText::RequestHeader(HeaderName::try_from(key.as_str()).unwrap())
+                    }
+                    "o" => {
+                        FormatText::ResponseHeader(HeaderName::try_from(key.as_str()).unwrap())
+                    }
                     "e" => FormatText::EnvironHeader(key.as_str().to_owned()),
+                    "xi" => FormatText::CustomRequest(key.as_str().to_owned(), None),
                     _ => unreachable!(),
                 })
             } else {
@@ -366,11 +418,12 @@ impl Format {
     }
 }
 
-/// A string of text to be logged. This is either one of the data
-/// fields supported by the `Logger`, or a custom `String`.
-#[doc(hidden)]
+/// A string of text to be logged.
+///
+/// This is either one of the data fields supported by the `Logger`, or a custom `String`.
+#[non_exhaustive]
 #[derive(Debug, Clone)]
-pub enum FormatText {
+enum FormatText {
     Str(String),
     Percent,
     RequestLine,
@@ -385,16 +438,34 @@ pub enum FormatText {
     RequestHeader(HeaderName),
     ResponseHeader(HeaderName),
     EnvironHeader(String),
+    CustomRequest(String, Option<CustomRequestFn>),
+}
+
+#[derive(Clone)]
+struct CustomRequestFn {
+    inner_fn: Rc<dyn Fn(&ServiceRequest) -> String>,
+}
+
+impl CustomRequestFn {
+    fn call(&self, req: &ServiceRequest) -> String {
+        (self.inner_fn)(req)
+    }
+}
+
+impl fmt::Debug for CustomRequestFn {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str("custom_request_fn")
+    }
 }
 
 impl FormatText {
     fn render(
         &self,
-        fmt: &mut Formatter<'_>,
+        fmt: &mut fmt::Formatter<'_>,
         size: usize,
         entry_time: OffsetDateTime,
     ) -> Result<(), fmt::Error> {
-        match *self {
+        match self {
             FormatText::Str(ref string) => fmt.write_str(string),
             FormatText::Percent => "%".fmt(fmt),
             FormatText::ResponseSize => size.fmt(fmt),
@@ -420,7 +491,7 @@ impl FormatText {
     }
 
     fn render_response<B>(&mut self, res: &HttpResponse<B>) {
-        match *self {
+        match self {
             FormatText::ResponseStatus => {
                 *self = FormatText::Str(format!("{}", res.status().as_u16()))
             }
@@ -436,12 +507,12 @@ impl FormatText {
                 };
                 *self = FormatText::Str(s.to_string())
             }
-            _ => (),
+            _ => {}
         }
     }
 
     fn render_request(&mut self, now: OffsetDateTime, req: &ServiceRequest) {
-        match *self {
+        match self {
             FormatText::RequestLine => {
                 *self = if req.query_string().is_empty() {
                     FormatText::Str(format!(
@@ -461,9 +532,7 @@ impl FormatText {
                 };
             }
             FormatText::UrlPath => *self = FormatText::Str(req.path().to_string()),
-            FormatText::RequestTime => {
-                *self = FormatText::Str(now.format("%Y-%m-%dT%H:%M:%S"))
-            }
+            FormatText::RequestTime => *self = FormatText::Str(now.format("%Y-%m-%dT%H:%M:%S")),
             FormatText::RequestHeader(ref name) => {
                 let s = if let Some(val) = req.headers().get(name) {
                     if let Ok(s) = val.to_str() {
@@ -485,25 +554,33 @@ impl FormatText {
                 *self = s;
             }
             FormatText::RealIPRemoteAddr => {
-                let s = if let Some(remote) = req.connection_info().realip_remote_addr()
-                {
+                let s = if let Some(remote) = req.connection_info().realip_remote_addr() {
                     FormatText::Str(remote.to_string())
                 } else {
                     FormatText::Str("-".to_string())
                 };
                 *self = s;
             }
-            _ => (),
+            FormatText::CustomRequest(_, request_fn) => {
+                let s = match request_fn {
+                    Some(f) => FormatText::Str(f.call(req)),
+                    None => FormatText::Str("-".to_owned()),
+                };
+
+                *self = s;
+            }
+            _ => {}
         }
     }
 }
 
+/// Converter to get a String from something that writes to a Formatter.
 pub(crate) struct FormatDisplay<'a>(
-    &'a dyn Fn(&mut Formatter<'_>) -> Result<(), fmt::Error>,
+    &'a dyn Fn(&mut fmt::Formatter<'_>) -> Result<(), fmt::Error>,
 );
 
 impl<'a> fmt::Display for FormatDisplay<'a> {
-    fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), fmt::Error> {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
         (self.0)(fmt)
     }
 }
@@ -515,38 +592,63 @@ mod tests {
 
     use super::*;
     use crate::http::{header, StatusCode};
-    use crate::test::TestRequest;
+    use crate::test::{self, TestRequest};
 
     #[actix_rt::test]
     async fn test_logger() {
         let srv = |req: ServiceRequest| {
             ok(req.into_response(
                 HttpResponse::build(StatusCode::OK)
-                    .header("X-Test", "ttt")
+                    .insert_header(("X-Test", "ttt"))
                     .finish(),
             ))
         };
         let logger = Logger::new("%% %{User-Agent}i %{X-Test}o %{HOME}e %D test");
 
-        let mut srv = logger.new_transform(srv.into_service()).await.unwrap();
+        let srv = logger.new_transform(srv.into_service()).await.unwrap();
 
-        let req = TestRequest::with_header(
-            header::USER_AGENT,
-            header::HeaderValue::from_static("ACTIX-WEB"),
-        )
-        .to_srv_request();
+        let req = TestRequest::default()
+            .insert_header((
+                header::USER_AGENT,
+                header::HeaderValue::from_static("ACTIX-WEB"),
+            ))
+            .to_srv_request();
         let _res = srv.call(req).await;
     }
 
+    #[actix_rt::test]
+    async fn test_logger_exclude_regex() {
+        let srv = |req: ServiceRequest| {
+            ok(req.into_response(
+                HttpResponse::build(StatusCode::OK)
+                    .insert_header(("X-Test", "ttt"))
+                    .finish(),
+            ))
+        };
+        let logger =
+            Logger::new("%% %{User-Agent}i %{X-Test}o %{HOME}e %D test").exclude_regex("\\w");
+
+        let srv = logger.new_transform(srv.into_service()).await.unwrap();
+
+        let req = TestRequest::default()
+            .insert_header((
+                header::USER_AGENT,
+                header::HeaderValue::from_static("ACTIX-WEB"),
+            ))
+            .to_srv_request();
+        let _res = srv.call(req).await.unwrap();
+    }
+
     #[actix_rt::test]
     async fn test_url_path() {
         let mut format = Format::new("%T %U");
-        let req = TestRequest::with_header(
-            header::USER_AGENT,
-            header::HeaderValue::from_static("ACTIX-WEB"),
-        )
-        .uri("/test/route/yeah")
-        .to_srv_request();
+        let req = TestRequest::default()
+            .insert_header((
+                header::USER_AGENT,
+                header::HeaderValue::from_static("ACTIX-WEB"),
+            ))
+            .uri("/test/route/yeah")
+            .to_srv_request();
 
         let now = OffsetDateTime::now_utc();
         for unit in &mut format.0 {
@@ -558,7 +660,7 @@ mod tests {
             unit.render_response(&resp);
         }
 
-        let render = |fmt: &mut Formatter<'_>| {
+        let render = |fmt: &mut fmt::Formatter<'_>| {
             for unit in &format.0 {
                 unit.render(fmt, 1024, now)?;
             }
@@ -573,12 +675,13 @@ mod tests {
     async fn test_default_format() {
         let mut format = Format::default();
 
-        let req = TestRequest::with_header(
-            header::USER_AGENT,
-            header::HeaderValue::from_static("ACTIX-WEB"),
-        )
-        .peer_addr("127.0.0.1:8081".parse().unwrap())
-        .to_srv_request();
+        let req = TestRequest::default()
+            .insert_header((
+                header::USER_AGENT,
+                header::HeaderValue::from_static("ACTIX-WEB"),
+            ))
+            .peer_addr("127.0.0.1:8081".parse().unwrap())
+            .to_srv_request();
 
         let now = OffsetDateTime::now_utc();
         for unit in &mut format.0 {
@@ -591,7 +694,7 @@ mod tests {
         }
 
         let entry_time = OffsetDateTime::now_utc();
-        let render = |fmt: &mut Formatter<'_>| {
+        let render = |fmt: &mut fmt::Formatter<'_>| {
             for unit in &format.0 {
                 unit.render(fmt, 1024, entry_time)?;
             }
@@ -619,7 +722,7 @@ mod tests {
             unit.render_response(&resp);
         }
 
-        let render = |fmt: &mut Formatter<'_>| {
+        let render = |fmt: &mut fmt::Formatter<'_>| {
             for unit in &format.0 {
                 unit.render(fmt, 1024, now)?;
             }
@@ -633,13 +736,12 @@ mod tests {
     async fn test_remote_addr_format() {
         let mut format = Format::new("%{r}a");
 
-        let req = TestRequest::with_header(
-            header::FORWARDED,
-            header::HeaderValue::from_static(
-                "for=192.0.2.60;proto=http;by=203.0.113.43",
-            ),
-        )
-        .to_srv_request();
+        let req = TestRequest::default()
+            .insert_header((
+                header::FORWARDED,
+                header::HeaderValue::from_static("for=192.0.2.60;proto=http;by=203.0.113.43"),
+            ))
+            .to_srv_request();
 
         let now = OffsetDateTime::now_utc();
         for unit in &mut format.0 {
@@ -652,7 +754,7 @@ mod tests {
         }
 
         let entry_time = OffsetDateTime::now_utc();
-        let render = |fmt: &mut Formatter<'_>| {
+        let render = |fmt: &mut fmt::Formatter<'_>| {
             for unit in &format.0 {
                 unit.render(fmt, 1024, entry_time)?;
             }
@@ -662,4 +764,45 @@ mod tests {
         println!("{}", s);
         assert!(s.contains("192.0.2.60"));
     }
+
+    #[actix_rt::test]
+    async fn test_custom_closure_log() {
+        let mut logger = Logger::new("test %{CUSTOM}xi")
+            .custom_request_replace("CUSTOM", |_req: &ServiceRequest| -> String {
+                String::from("custom_log")
+            });
+        let mut unit = Rc::get_mut(&mut logger.0).unwrap().format.0[1].clone();
+
+        let label = match &unit {
+            FormatText::CustomRequest(label, _) => label,
+            ft => panic!("expected CustomRequest, found {:?}", ft),
+        };
+
+        assert_eq!(label, "CUSTOM");
+
+        let req = TestRequest::default().to_srv_request();
+        let now = OffsetDateTime::now_utc();
+
+        unit.render_request(now, &req);
+
+        let render = |fmt: &mut fmt::Formatter<'_>| unit.render(fmt, 1024, now);
+
+        let log_output = FormatDisplay(&render).to_string();
+        assert_eq!(log_output, "custom_log");
+    }
+
+    #[actix_rt::test]
+    async fn test_closure_logger_in_middleware() {
+        let captured = "custom log replacement";
+
+        let logger = Logger::new("%{CUSTOM}xi")
+            .custom_request_replace("CUSTOM", move |_req: &ServiceRequest| -> String {
+                captured.to_owned()
+            });
+
+        let srv = logger.new_transform(test::ok_service()).await.unwrap();
+
+        let req = TestRequest::default().to_srv_request();
+        srv.call(req).await.unwrap();
+    }
 }
diff --git a/src/middleware/mod.rs b/src/middleware/mod.rs
index 12c12a98c..e24782f07 100644
--- a/src/middleware/mod.rs
+++ b/src/middleware/mod.rs
@@ -1,17 +1,20 @@
-//! Middlewares
+//! Commonly used middleware.
+
+mod compat;
+mod condition;
+mod default_headers;
+mod err_handlers;
+mod logger;
+mod normalize;
+
+pub use self::compat::Compat;
+pub use self::condition::Condition;
+pub use self::default_headers::DefaultHeaders;
+pub use self::err_handlers::{ErrorHandlerResponse, ErrorHandlers};
+pub use self::logger::Logger;
+pub use self::normalize::{NormalizePath, TrailingSlash};
 
 #[cfg(feature = "compress")]
 mod compress;
 #[cfg(feature = "compress")]
 pub use self::compress::Compress;
-
-mod condition;
-mod defaultheaders;
-pub mod errhandlers;
-mod logger;
-pub mod normalize;
-
-pub use self::condition::Condition;
-pub use self::defaultheaders::DefaultHeaders;
-pub use self::logger::Logger;
-pub use self::normalize::NormalizePath;
diff --git a/src/middleware/normalize.rs b/src/middleware/normalize.rs
index e0ecd90dc..ea21a7215 100644
--- a/src/middleware/normalize.rs
+++ b/src/middleware/normalize.rs
@@ -1,59 +1,91 @@
-//! `Middleware` to normalize request's URI
-use std::task::{Context, Poll};
+//! For middleware documentation, see [`NormalizePath`].
 
 use actix_http::http::{PathAndQuery, Uri};
 use actix_service::{Service, Transform};
 use bytes::Bytes;
-use futures_util::future::{ok, Ready};
+use futures_util::future::{ready, Ready};
 use regex::Regex;
 
-use crate::service::{ServiceRequest, ServiceResponse};
-use crate::Error;
+use crate::{
+    service::{ServiceRequest, ServiceResponse},
+    Error,
+};
 
-/// To be used when constructing `NormalizePath` to define it's behavior.
+/// Determines the behavior of the [`NormalizePath`] middleware.
+///
+/// The default is `TrailingSlash::Trim`.
 #[non_exhaustive]
-#[derive(Clone, Copy)]
+#[derive(Debug, Clone, Copy)]
 pub enum TrailingSlash {
-    /// Always add a trailing slash to the end of the path.
-    /// This will require all routes to end in a trailing slash for them to be accessible.
-    Always,
+    /// Trim trailing slashes from the end of the path.
+    ///
+    /// Using this will require all routes to omit trailing slashes for them to be accessible.
+    Trim,
+
     /// Only merge any present multiple trailing slashes.
     ///
-    /// Note: This option provides the best compatibility with the v2 version of this middlware.
+    /// This option provides the best compatibility with behavior in actix-web v2.0.
     MergeOnly,
-    /// Trim trailing slashes from the end of the path.
-    Trim,
+
+    /// Always add a trailing slash to the end of the path.
+    ///
+    /// Using this will require all routes have a trailing slash for them to be accessible.
+    Always,
 }
 
 impl Default for TrailingSlash {
     fn default() -> Self {
-        TrailingSlash::Always
+        TrailingSlash::Trim
     }
 }
 
-#[derive(Default, Clone, Copy)]
-/// `Middleware` to normalize request's URI in place
+/// Middleware for normalizing a request's path so that routes can be matched more flexibly.
 ///
-/// Performs following:
-///
-/// - Merges multiple slashes into one.
+/// # Normalization Steps
+/// - Merges consecutive slashes into one. (For example, `/path//one` always becomes `/path/one`.)
 /// - Appends a trailing slash if one is not present, removes one if present, or keeps trailing
-///   slashes as-is, depending on the supplied `TrailingSlash` variant.
+///   slashes as-is, depending on which [`TrailingSlash`] variant is supplied
+///   to [`new`](NormalizePath::new()).
 ///
+/// # Default Behavior
+/// The default constructor chooses to strip trailing slashes from the end of paths with them
+/// ([`TrailingSlash::Trim`]). The implication is that route definitions should be defined without
+/// trailing slashes or else they will be inaccessible (or vice versa when using the
+/// `TrailingSlash::Always` behavior), as shown in the example tests below.
+///
+/// # Examples
 /// ```rust
-/// use actix_web::{web, http, middleware, App, HttpResponse};
+/// use actix_web::{web, middleware, App};
 ///
-/// # fn main() {
+/// # actix_web::rt::System::new().block_on(async {
 /// let app = App::new()
 ///     .wrap(middleware::NormalizePath::default())
-///     .service(
-///         web::resource("/test")
-///             .route(web::get().to(|| HttpResponse::Ok()))
-///             .route(web::method(http::Method::HEAD).to(|| HttpResponse::MethodNotAllowed()))
-///     );
-/// # }
+///     .route("/test", web::get().to(|| async { "test" }))
+///     .route("/unmatchable/", web::get().to(|| async { "unmatchable" }));
+///
+/// use actix_web::http::StatusCode;
+/// use actix_web::test::{call_service, init_service, TestRequest};
+///
+/// let app = init_service(app).await;
+///
+/// let req = TestRequest::with_uri("/test").to_request();
+/// let res = call_service(&app, req).await;
+/// assert_eq!(res.status(), StatusCode::OK);
+///
+/// let req = TestRequest::with_uri("/test/").to_request();
+/// let res = call_service(&app, req).await;
+/// assert_eq!(res.status(), StatusCode::OK);
+///
+/// let req = TestRequest::with_uri("/unmatchable").to_request();
+/// let res = call_service(&app, req).await;
+/// assert_eq!(res.status(), StatusCode::NOT_FOUND);
+///
+/// let req = TestRequest::with_uri("/unmatchable/").to_request();
+/// let res = call_service(&app, req).await;
+/// assert_eq!(res.status(), StatusCode::NOT_FOUND);
+/// # })
 /// ```
-
+#[derive(Debug, Clone, Copy, Default)]
 pub struct NormalizePath(TrailingSlash);
 
 impl NormalizePath {
@@ -63,49 +95,44 @@ impl NormalizePath {
     }
 }
 
-impl<S, B> Transform<S> for NormalizePath
+impl<S, B> Transform<S, ServiceRequest> for NormalizePath
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
     S::Future: 'static,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<B>;
     type Error = Error;
-    type InitError = ();
     type Transform = NormalizePathNormalization<S>;
+    type InitError = ();
     type Future = Ready<Result<Self::Transform, Self::InitError>>;
 
     fn new_transform(&self, service: S) -> Self::Future {
-        ok(NormalizePathNormalization {
+        ready(Ok(NormalizePathNormalization {
             service,
             merge_slash: Regex::new("//+").unwrap(),
             trailing_slash_behavior: self.0,
-        })
+        }))
     }
 }
 
-#[doc(hidden)]
 pub struct NormalizePathNormalization<S> {
     service: S,
     merge_slash: Regex,
     trailing_slash_behavior: TrailingSlash,
 }
 
-impl<S, B> Service for NormalizePathNormalization<S>
+impl<S, B> Service<ServiceRequest> for NormalizePathNormalization<S>
 where
-    S: Service<Request = ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
     S::Future: 'static,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse<B>;
     type Error = Error;
     type Future = S::Future;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.service.poll_ready(cx)
-    }
+    actix_service::forward_ready!(service);
 
-    fn call(&mut self, mut req: ServiceRequest) -> Self::Future {
+    fn call(&self, mut req: ServiceRequest) -> Self::Future {
         let head = req.head_mut();
 
         let original_path = head.uri.path();
@@ -137,9 +164,9 @@ where
         // so the change can not be deduced from the length comparison
         if path != original_path {
             let mut parts = head.uri.clone().into_parts();
-            let pq = parts.path_and_query.as_ref().unwrap();
+            let query = parts.path_and_query.as_ref().and_then(|pq| pq.query());
 
-            let path = if let Some(q) = pq.query() {
+            let path = if let Some(q) = query {
                 Bytes::from(format!("{}?{}", path, q))
             } else {
                 Bytes::copy_from_slice(path.as_bytes())
@@ -160,52 +187,54 @@ mod tests {
     use actix_service::IntoService;
 
     use super::*;
-    use crate::dev::ServiceRequest;
-    use crate::test::{call_service, init_service, TestRequest};
-    use crate::{web, App, HttpResponse};
+    use crate::{
+        dev::ServiceRequest,
+        test::{call_service, init_service, TestRequest},
+        web, App, HttpResponse,
+    };
 
     #[actix_rt::test]
     async fn test_wrap() {
-        let mut app = init_service(
+        let app = init_service(
             App::new()
                 .wrap(NormalizePath::default())
                 .service(web::resource("/").to(HttpResponse::Ok))
-                .service(web::resource("/v1/something/").to(HttpResponse::Ok)),
+                .service(web::resource("/v1/something").to(HttpResponse::Ok)),
         )
         .await;
 
         let req = TestRequest::with_uri("/").to_request();
-        let res = call_service(&mut app, req).await;
+        let res = call_service(&app, req).await;
         assert!(res.status().is_success());
 
         let req = TestRequest::with_uri("/?query=test").to_request();
-        let res = call_service(&mut app, req).await;
+        let res = call_service(&app, req).await;
         assert!(res.status().is_success());
 
         let req = TestRequest::with_uri("///").to_request();
-        let res = call_service(&mut app, req).await;
+        let res = call_service(&app, req).await;
         assert!(res.status().is_success());
 
         let req = TestRequest::with_uri("/v1//something////").to_request();
-        let res = call_service(&mut app, req).await;
+        let res = call_service(&app, req).await;
         assert!(res.status().is_success());
 
         let req2 = TestRequest::with_uri("//v1/something").to_request();
-        let res2 = call_service(&mut app, req2).await;
+        let res2 = call_service(&app, req2).await;
         assert!(res2.status().is_success());
 
         let req3 = TestRequest::with_uri("//v1//////something").to_request();
-        let res3 = call_service(&mut app, req3).await;
+        let res3 = call_service(&app, req3).await;
         assert!(res3.status().is_success());
 
         let req4 = TestRequest::with_uri("/v1//something").to_request();
-        let res4 = call_service(&mut app, req4).await;
+        let res4 = call_service(&app, req4).await;
         assert!(res4.status().is_success());
     }
 
     #[actix_rt::test]
     async fn trim_trailing_slashes() {
-        let mut app = init_service(
+        let app = init_service(
             App::new()
                 .wrap(NormalizePath(TrailingSlash::Trim))
                 .service(web::resource("/").to(HttpResponse::Ok))
@@ -215,37 +244,37 @@ mod tests {
 
         // root paths should still work
         let req = TestRequest::with_uri("/").to_request();
-        let res = call_service(&mut app, req).await;
+        let res = call_service(&app, req).await;
         assert!(res.status().is_success());
 
         let req = TestRequest::with_uri("/?query=test").to_request();
-        let res = call_service(&mut app, req).await;
+        let res = call_service(&app, req).await;
         assert!(res.status().is_success());
 
         let req = TestRequest::with_uri("///").to_request();
-        let res = call_service(&mut app, req).await;
+        let res = call_service(&app, req).await;
         assert!(res.status().is_success());
 
         let req = TestRequest::with_uri("/v1/something////").to_request();
-        let res = call_service(&mut app, req).await;
+        let res = call_service(&app, req).await;
         assert!(res.status().is_success());
 
         let req2 = TestRequest::with_uri("/v1/something/").to_request();
-        let res2 = call_service(&mut app, req2).await;
+        let res2 = call_service(&app, req2).await;
         assert!(res2.status().is_success());
 
         let req3 = TestRequest::with_uri("//v1//something//").to_request();
-        let res3 = call_service(&mut app, req3).await;
+        let res3 = call_service(&app, req3).await;
         assert!(res3.status().is_success());
 
         let req4 = TestRequest::with_uri("//v1//something").to_request();
-        let res4 = call_service(&mut app, req4).await;
+        let res4 = call_service(&app, req4).await;
         assert!(res4.status().is_success());
     }
 
     #[actix_rt::test]
-    async fn keep_trailing_slash_unchange() {
-        let mut app = init_service(
+    async fn keep_trailing_slash_unchanged() {
+        let app = init_service(
             App::new()
                 .wrap(NormalizePath(TrailingSlash::MergeOnly))
                 .service(web::resource("/").to(HttpResponse::Ok))
@@ -270,7 +299,7 @@ mod tests {
 
         for (path, success) in tests {
             let req = TestRequest::with_uri(path).to_request();
-            let res = call_service(&mut app, req).await;
+            let res = call_service(&app, req).await;
             assert_eq!(res.status().is_success(), success);
         }
     }
@@ -278,11 +307,11 @@ mod tests {
     #[actix_rt::test]
     async fn test_in_place_normalization() {
         let srv = |req: ServiceRequest| {
-            assert_eq!("/v1/something/", req.path());
-            ok(req.into_response(HttpResponse::Ok().finish()))
+            assert_eq!("/v1/something", req.path());
+            ready(Ok(req.into_response(HttpResponse::Ok().finish())))
         };
 
-        let mut normalize = NormalizePath::default()
+        let normalize = NormalizePath::default()
             .new_transform(srv.into_service())
             .await
             .unwrap();
@@ -306,14 +335,14 @@ mod tests {
 
     #[actix_rt::test]
     async fn should_normalize_nothing() {
-        const URI: &str = "/v1/something/";
+        const URI: &str = "/v1/something";
 
         let srv = |req: ServiceRequest| {
             assert_eq!(URI, req.path());
-            ok(req.into_response(HttpResponse::Ok().finish()))
+            ready(Ok(req.into_response(HttpResponse::Ok().finish())))
         };
 
-        let mut normalize = NormalizePath::default()
+        let normalize = NormalizePath::default()
             .new_transform(srv.into_service())
             .await
             .unwrap();
@@ -324,20 +353,18 @@ mod tests {
     }
 
     #[actix_rt::test]
-    async fn should_normalize_notrail() {
-        const URI: &str = "/v1/something";
-
+    async fn should_normalize_no_trail() {
         let srv = |req: ServiceRequest| {
-            assert_eq!(URI.to_string() + "/", req.path());
-            ok(req.into_response(HttpResponse::Ok().finish()))
+            assert_eq!("/v1/something", req.path());
+            ready(Ok(req.into_response(HttpResponse::Ok().finish())))
         };
 
-        let mut normalize = NormalizePath::default()
+        let normalize = NormalizePath::default()
             .new_transform(srv.into_service())
             .await
             .unwrap();
 
-        let req = TestRequest::with_uri(URI).to_srv_request();
+        let req = TestRequest::with_uri("/v1/something/").to_srv_request();
         let res = normalize.call(req).await.unwrap();
         assert!(res.status().is_success());
     }
diff --git a/src/request.rs b/src/request.rs
index a1b42f926..514b7466e 100644
--- a/src/request.rs
+++ b/src/request.rs
@@ -6,8 +6,9 @@ use actix_http::http::{HeaderMap, Method, Uri, Version};
 use actix_http::{Error, Extensions, HttpMessage, Message, Payload, RequestHead};
 use actix_router::{Path, Url};
 use futures_util::future::{ok, Ready};
-use tinyvec::TinyVec;
+use smallvec::SmallVec;
 
+use crate::app_service::AppInitServiceState;
 use crate::config::AppConfig;
 use crate::error::UrlGenerationError;
 use crate::extract::FromRequest;
@@ -16,16 +17,19 @@ use crate::rmap::ResourceMap;
 
 #[derive(Clone)]
 /// An HTTP Request
-pub struct HttpRequest(pub(crate) Rc<HttpRequestInner>);
+pub struct HttpRequest {
+    /// # Panics
+    /// `Rc<HttpRequestInner>` is used exclusively and NO `Weak<HttpRequestInner>`
+    /// is allowed anywhere in the code. Weak pointer is purposely ignored when
+    /// doing `Rc`'s ref counter check. Expect panics if this invariant is violated.
+    pub(crate) inner: Rc<HttpRequestInner>,
+}
 
 pub(crate) struct HttpRequestInner {
     pub(crate) head: Message<RequestHead>,
     pub(crate) path: Path<Url>,
-    pub(crate) payload: Payload,
-    pub(crate) app_data: TinyVec<[Rc<Extensions>; 4]>,
-    rmap: Rc<ResourceMap>,
-    config: AppConfig,
-    pool: &'static HttpRequestPool,
+    pub(crate) app_data: SmallVec<[Rc<Extensions>; 4]>,
+    app_state: Rc<AppInitServiceState>,
 }
 
 impl HttpRequest {
@@ -33,24 +37,20 @@ impl HttpRequest {
     pub(crate) fn new(
         path: Path<Url>,
         head: Message<RequestHead>,
-        payload: Payload,
-        rmap: Rc<ResourceMap>,
-        config: AppConfig,
+        app_state: Rc<AppInitServiceState>,
         app_data: Rc<Extensions>,
-        pool: &'static HttpRequestPool,
     ) -> HttpRequest {
-        let mut data = TinyVec::<[Rc<Extensions>; 4]>::new();
+        let mut data = SmallVec::<[Rc<Extensions>; 4]>::new();
         data.push(app_data);
 
-        HttpRequest(Rc::new(HttpRequestInner {
-            head,
-            path,
-            payload,
-            rmap,
-            config,
-            app_data: data,
-            pool,
-        }))
+        HttpRequest {
+            inner: Rc::new(HttpRequestInner {
+                head,
+                path,
+                app_state,
+                app_data: data,
+            }),
+        }
     }
 }
 
@@ -58,14 +58,14 @@ impl HttpRequest {
     /// This method returns reference to the request head
     #[inline]
     pub fn head(&self) -> &RequestHead {
-        &self.0.head
+        &self.inner.head
     }
 
     /// This method returns mutable reference to the request head.
-    /// panics if multiple references of http request exists.
+    /// panics if multiple references of HTTP request exists.
     #[inline]
     pub(crate) fn head_mut(&mut self) -> &mut RequestHead {
-        &mut Rc::get_mut(&mut self.0).unwrap().head
+        &mut Rc::get_mut(&mut self.inner).unwrap().head
     }
 
     /// Request's uri.
@@ -118,12 +118,12 @@ impl HttpRequest {
     /// access the matched value for that segment.
     #[inline]
     pub fn match_info(&self) -> &Path<Url> {
-        &self.0.path
+        &self.inner.path
     }
 
     #[inline]
     pub(crate) fn match_info_mut(&mut self) -> &mut Path<Url> {
-        &mut Rc::get_mut(&mut self.0).unwrap().path
+        &mut Rc::get_mut(&mut self.inner).unwrap().path
     }
 
     /// The resource definition pattern that matched the path. Useful for logging and metrics.
@@ -134,7 +134,7 @@ impl HttpRequest {
     /// Returns a None when no resource is fully matched, including default services.
     #[inline]
     pub fn match_pattern(&self) -> Option<String> {
-        self.0.rmap.match_pattern(self.path())
+        self.resource_map().match_pattern(self.path())
     }
 
     /// The resource name that matched the path. Useful for logging and metrics.
@@ -142,7 +142,7 @@ impl HttpRequest {
     /// Returns a None when no resource is fully matched, including default services.
     #[inline]
     pub fn match_name(&self) -> Option<&str> {
-        self.0.rmap.match_name(self.path())
+        self.resource_map().match_name(self.path())
     }
 
     /// Request extensions
@@ -175,16 +175,12 @@ impl HttpRequest {
     ///         );
     /// }
     /// ```
-    pub fn url_for<U, I>(
-        &self,
-        name: &str,
-        elements: U,
-    ) -> Result<url::Url, UrlGenerationError>
+    pub fn url_for<U, I>(&self, name: &str, elements: U) -> Result<url::Url, UrlGenerationError>
     where
         U: IntoIterator<Item = I>,
         I: AsRef<str>,
     {
-        self.0.rmap.url_for(&self, name, elements)
+        self.resource_map().url_for(&self, name, elements)
     }
 
     /// Generate url for named resource
@@ -199,15 +195,17 @@ impl HttpRequest {
     #[inline]
     /// Get a reference to a `ResourceMap` of current application.
     pub fn resource_map(&self) -> &ResourceMap {
-        &self.0.rmap
+        &self.app_state().rmap()
     }
 
-    /// Peer socket address
+    /// Peer socket address.
     ///
-    /// Peer address is actual socket address, if proxy is used in front of
-    /// actix http server, then peer address would be address of this proxy.
+    /// Peer address is the directly connected peer's socket address. If a proxy is used in front of
+    /// the Actix Web server, then it would be address of this proxy.
     ///
     /// To get client connection information `.connection_info()` should be used.
+    ///
+    /// Will only return None when called in unit tests.
     #[inline]
     pub fn peer_addr(&self) -> Option<net::SocketAddr> {
         self.head().peer_addr
@@ -219,13 +217,13 @@ impl HttpRequest {
     /// borrowed.
     #[inline]
     pub fn connection_info(&self) -> Ref<'_, ConnectionInfo> {
-        ConnectionInfo::get(self.head(), &*self.app_config())
+        ConnectionInfo::get(self.head(), self.app_config())
     }
 
     /// App config
     #[inline]
     pub fn app_config(&self) -> &AppConfig {
-        &self.0.config
+        self.app_state().config()
     }
 
     /// Get an application data object stored with `App::data` or `App::app_data`
@@ -237,7 +235,7 @@ impl HttpRequest {
     /// let opt_t = req.app_data::<Data<T>>();
     /// ```
     pub fn app_data<T: 'static>(&self) -> Option<&T> {
-        for container in self.0.app_data.iter().rev() {
+        for container in self.inner.app_data.iter().rev() {
             if let Some(data) = container.get::<T>() {
                 return Some(data);
             }
@@ -245,6 +243,11 @@ impl HttpRequest {
 
         None
     }
+
+    #[inline]
+    fn app_state(&self) -> &AppInitServiceState {
+        &*self.inner.app_state
+    }
 }
 
 impl HttpMessage for HttpRequest {
@@ -259,13 +262,13 @@ impl HttpMessage for HttpRequest {
     /// Request extensions
     #[inline]
     fn extensions(&self) -> Ref<'_, Extensions> {
-        self.0.head.extensions()
+        self.inner.head.extensions()
     }
 
     /// Mutable reference to a the request's extensions
     #[inline]
     fn extensions_mut(&self) -> RefMut<'_, Extensions> {
-        self.0.head.extensions_mut()
+        self.inner.head.extensions_mut()
     }
 
     #[inline]
@@ -277,11 +280,19 @@ impl HttpMessage for HttpRequest {
 impl Drop for HttpRequest {
     fn drop(&mut self) {
         // if possible, contribute to current worker's HttpRequest allocation pool
-        if Rc::strong_count(&self.0) == 1 {
-            let v = &mut self.0.pool.0.borrow_mut();
-            if v.len() < 128 {
-                self.extensions_mut().clear();
-                v.push(self.0.clone());
+
+        // This relies on no Weak<HttpRequestInner> exists anywhere.(There is none)
+        if let Some(inner) = Rc::get_mut(&mut self.inner) {
+            if inner.app_state.pool().is_available() {
+                // clear additional app_data and keep the root one for reuse.
+                inner.app_data.truncate(1);
+                // inner is borrowed mut here. get head's Extension mutably
+                // to reduce borrow check
+                inner.head.extensions.get_mut().clear();
+
+                // a re-borrow of pool is necessary here.
+                let req = self.inner.clone();
+                self.app_state().pool().push(req);
             }
         }
     }
@@ -323,8 +334,8 @@ impl fmt::Debug for HttpRequest {
         writeln!(
             f,
             "\nHttpRequest {:?} {}:{}",
-            self.0.head.version,
-            self.0.head.method,
+            self.inner.head.version,
+            self.inner.head.method,
             self.path()
         )?;
         if !self.query_string().is_empty() {
@@ -350,25 +361,50 @@ impl fmt::Debug for HttpRequest {
 /// Request objects are added when they are dropped (see `<HttpRequest as Drop>::drop`) and re-used
 /// in `<AppInitService as Service>::call` when there are available objects in the list.
 ///
-/// The pool's initial capacity is 128 items.
-pub(crate) struct HttpRequestPool(RefCell<Vec<Rc<HttpRequestInner>>>);
+/// The pool's default capacity is 128 items.
+pub(crate) struct HttpRequestPool {
+    inner: RefCell<Vec<Rc<HttpRequestInner>>>,
+    cap: usize,
+}
+
+impl Default for HttpRequestPool {
+    fn default() -> Self {
+        Self::with_capacity(128)
+    }
+}
 
 impl HttpRequestPool {
-    /// Allocates a slab of memory for pool use.
-    pub(crate) fn create() -> &'static HttpRequestPool {
-        let pool = HttpRequestPool(RefCell::new(Vec::with_capacity(128)));
-        Box::leak(Box::new(pool))
+    pub(crate) fn with_capacity(cap: usize) -> Self {
+        HttpRequestPool {
+            inner: RefCell::new(Vec::with_capacity(cap)),
+            cap,
+        }
     }
 
     /// Re-use a previously allocated (but now completed/discarded) HttpRequest object.
     #[inline]
-    pub(crate) fn get_request(&self) -> Option<HttpRequest> {
-        self.0.borrow_mut().pop().map(HttpRequest)
+    pub(crate) fn pop(&self) -> Option<HttpRequest> {
+        self.inner
+            .borrow_mut()
+            .pop()
+            .map(|inner| HttpRequest { inner })
+    }
+
+    /// Check if the pool still has capacity for request storage.
+    #[inline]
+    pub(crate) fn is_available(&self) -> bool {
+        self.inner.borrow_mut().len() < self.cap
+    }
+
+    /// Push a request to pool.
+    #[inline]
+    pub(crate) fn push(&self, req: Rc<HttpRequestInner>) {
+        self.inner.borrow_mut().push(req);
     }
 
     /// Clears all allocated HttpRequest objects.
     pub(crate) fn clear(&self) {
-        self.0.borrow_mut().clear()
+        self.inner.borrow_mut().clear()
     }
 }
 
@@ -385,31 +421,34 @@ mod tests {
 
     #[test]
     fn test_debug() {
-        let req =
-            TestRequest::with_header("content-type", "text/plain").to_http_request();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "text/plain"))
+            .to_http_request();
         let dbg = format!("{:?}", req);
         assert!(dbg.contains("HttpRequest"));
     }
 
     #[test]
+    #[cfg(feature = "cookies")]
     fn test_no_request_cookies() {
         let req = TestRequest::default().to_http_request();
         assert!(req.cookies().unwrap().is_empty());
     }
 
     #[test]
+    #[cfg(feature = "cookies")]
     fn test_request_cookies() {
         let req = TestRequest::default()
-            .header(header::COOKIE, "cookie1=value1")
-            .header(header::COOKIE, "cookie2=value2")
+            .append_header((header::COOKIE, "cookie1=value1"))
+            .append_header((header::COOKIE, "cookie2=value2"))
             .to_http_request();
         {
             let cookies = req.cookies().unwrap();
             assert_eq!(cookies.len(), 2);
-            assert_eq!(cookies[0].name(), "cookie2");
-            assert_eq!(cookies[0].value(), "value2");
-            assert_eq!(cookies[1].name(), "cookie1");
-            assert_eq!(cookies[1].value(), "value1");
+            assert_eq!(cookies[0].name(), "cookie1");
+            assert_eq!(cookies[0].value(), "value1");
+            assert_eq!(cookies[1].name(), "cookie2");
+            assert_eq!(cookies[1].value(), "value2");
         }
 
         let cookie = req.cookie("cookie1");
@@ -438,7 +477,8 @@ mod tests {
         assert!(rmap.has_resource("/user/test.html"));
         assert!(!rmap.has_resource("/test/unknown"));
 
-        let req = TestRequest::with_header(header::HOST, "www.rust-lang.org")
+        let req = TestRequest::default()
+            .insert_header((header::HOST, "www.rust-lang.org"))
             .rmap(rmap)
             .to_http_request();
 
@@ -468,7 +508,7 @@ mod tests {
         assert!(rmap.has_resource("/index.html"));
 
         let req = TestRequest::with_uri("/test")
-            .header(header::HOST, "www.rust-lang.org")
+            .insert_header((header::HOST, "www.rust-lang.org"))
             .rmap(rmap)
             .to_http_request();
         let url = req.url_for_static("index");
@@ -514,36 +554,55 @@ mod tests {
         );
     }
 
+    #[actix_rt::test]
+    async fn test_drop_http_request_pool() {
+        let srv = init_service(App::new().service(web::resource("/").to(
+            |req: HttpRequest| {
+                HttpResponse::Ok()
+                    .insert_header(("pool_cap", req.app_state().pool().cap))
+                    .finish()
+            },
+        )))
+        .await;
+
+        let req = TestRequest::default().to_request();
+        let resp = call_service(&srv, req).await;
+
+        drop(srv);
+
+        assert_eq!(resp.headers().get("pool_cap").unwrap(), "128");
+    }
+
     #[actix_rt::test]
     async fn test_data() {
-        let mut srv = init_service(App::new().app_data(10usize).service(
-            web::resource("/").to(|req: HttpRequest| {
+        let srv = init_service(App::new().app_data(10usize).service(web::resource("/").to(
+            |req: HttpRequest| {
                 if req.app_data::<usize>().is_some() {
                     HttpResponse::Ok()
                 } else {
                     HttpResponse::BadRequest()
                 }
-            }),
-        ))
+            },
+        )))
         .await;
 
         let req = TestRequest::default().to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
-        let mut srv = init_service(App::new().app_data(10u32).service(
-            web::resource("/").to(|req: HttpRequest| {
+        let srv = init_service(App::new().app_data(10u32).service(web::resource("/").to(
+            |req: HttpRequest| {
                 if req.app_data::<usize>().is_some() {
                     HttpResponse::Ok()
                 } else {
                     HttpResponse::BadRequest()
                 }
-            }),
-        ))
+            },
+        )))
         .await;
 
         let req = TestRequest::default().to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
     }
 
@@ -555,7 +614,7 @@ mod tests {
             HttpResponse::Ok().body(num.to_string())
         }
 
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .app_data(88usize)
                 .service(web::resource("/").route(web::get().to(echo_usize)))
@@ -586,7 +645,7 @@ mod tests {
             HttpResponse::Ok().body(num.to_string())
         }
 
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .app_data(88usize)
                 .service(web::resource("/").route(web::get().to(echo_usize)))
@@ -626,18 +685,18 @@ mod tests {
         let tracker = Rc::new(RefCell::new(Tracker { dropped: false }));
         {
             let tracker2 = Rc::clone(&tracker);
-            let mut srv = init_service(App::new().data(10u32).service(
-                web::resource("/").to(move |req: HttpRequest| {
+            let srv = init_service(App::new().data(10u32).service(web::resource("/").to(
+                move |req: HttpRequest| {
                     req.extensions_mut().insert(Foo {
                         tracker: Rc::clone(&tracker2),
                     });
                     HttpResponse::Ok()
-                }),
-            ))
+                },
+            )))
             .await;
 
             let req = TestRequest::default().to_request();
-            let resp = call_service(&mut srv, req).await;
+            let resp = call_service(&srv, req).await;
             assert_eq!(resp.status(), StatusCode::OK);
         }
 
@@ -646,7 +705,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn extract_path_pattern() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("/user/{id}")
                     .service(web::resource("/profile").route(web::get().to(
@@ -668,11 +727,47 @@ mod tests {
         .await;
 
         let req = TestRequest::get().uri("/user/22/profile").to_request();
-        let res = call_service(&mut srv, req).await;
+        let res = call_service(&srv, req).await;
         assert_eq!(res.status(), StatusCode::OK);
 
         let req = TestRequest::get().uri("/user/22/not-exist").to_request();
-        let res = call_service(&mut srv, req).await;
+        let res = call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::OK);
+    }
+
+    #[actix_rt::test]
+    async fn extract_path_pattern_complex() {
+        let srv = init_service(
+            App::new()
+                .service(web::scope("/user").service(web::scope("/{id}").service(
+                    web::resource("").to(move |req: HttpRequest| {
+                        assert_eq!(req.match_pattern(), Some("/user/{id}".to_owned()));
+
+                        HttpResponse::Ok().finish()
+                    }),
+                )))
+                .service(web::resource("/").to(move |req: HttpRequest| {
+                    assert_eq!(req.match_pattern(), Some("/".to_owned()));
+
+                    HttpResponse::Ok().finish()
+                }))
+                .default_service(web::to(move |req: HttpRequest| {
+                    assert!(req.match_pattern().is_none());
+                    HttpResponse::Ok().finish()
+                })),
+        )
+        .await;
+
+        let req = TestRequest::get().uri("/user/test").to_request();
+        let res = call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::OK);
+
+        let req = TestRequest::get().uri("/").to_request();
+        let res = call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::OK);
+
+        let req = TestRequest::get().uri("/not-exist").to_request();
+        let res = call_service(&srv, req).await;
         assert_eq!(res.status(), StatusCode::OK);
     }
 }
diff --git a/src/request_data.rs b/src/request_data.rs
new file mode 100644
index 000000000..beee8ac12
--- /dev/null
+++ b/src/request_data.rs
@@ -0,0 +1,175 @@
+use std::{any::type_name, ops::Deref};
+
+use actix_http::error::{Error, ErrorInternalServerError};
+use futures_util::future;
+
+use crate::{dev::Payload, FromRequest, HttpRequest};
+
+/// Request-local data extractor.
+///
+/// Request-local data is arbitrary data attached to an individual request, usually
+/// by middleware. It can be set via `extensions_mut` on [`HttpRequest`][htr_ext_mut]
+/// or [`ServiceRequest`][srv_ext_mut].
+///
+/// Unlike app data, request data is dropped when the request has finished processing. This makes it
+/// useful as a kind of messaging system between middleware and request handlers. It uses the same
+/// types-as-keys storage system as app data.
+///
+/// # Mutating Request Data
+/// Note that since extractors must output owned data, only types that `impl Clone` can use this
+/// extractor. A clone is taken of the required request data and can, therefore, not be directly
+/// mutated in-place. To mutate request data, continue to use [`HttpRequest::extensions_mut`] or
+/// re-insert the cloned data back into the extensions map. A `DerefMut` impl is intentionally not
+/// provided to make this potential foot-gun more obvious.
+///
+/// # Example
+/// ```rust,no_run
+/// # use actix_web::{web, HttpResponse, HttpRequest, Responder};
+///
+/// #[derive(Debug, Clone, PartialEq)]
+/// struct FlagFromMiddleware(String);
+///
+/// /// Use the `ReqData<T>` extractor to access request data in a handler.
+/// async fn handler(
+///     req: HttpRequest,
+///     opt_flag: Option<web::ReqData<FlagFromMiddleware>>,
+/// ) -> impl Responder {
+///     // use an optional extractor if the middleware is
+///     // not guaranteed to add this type of requests data
+///     if let Some(flag) = opt_flag {
+///         assert_eq!(&flag.into_inner(), req.extensions().get::<FlagFromMiddleware>().unwrap());
+///     }
+///     
+///     HttpResponse::Ok()
+/// }
+/// ```
+///
+/// [htr_ext_mut]: crate::HttpRequest::extensions_mut
+/// [srv_ext_mut]: crate::dev::ServiceRequest::extensions_mut
+#[derive(Debug, Clone)]
+pub struct ReqData<T: Clone + 'static>(T);
+
+impl<T: Clone + 'static> ReqData<T> {
+    /// Consumes the `ReqData`, returning its wrapped data.
+    pub fn into_inner(self) -> T {
+        self.0
+    }
+}
+
+impl<T: Clone + 'static> Deref for ReqData<T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        &self.0
+    }
+}
+
+impl<T: Clone + 'static> FromRequest for ReqData<T> {
+    type Config = ();
+    type Error = Error;
+    type Future = future::Ready<Result<Self, Error>>;
+
+    fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
+        if let Some(st) = req.extensions().get::<T>() {
+            future::ok(ReqData(st.clone()))
+        } else {
+            log::debug!(
+                "Failed to construct App-level ReqData extractor. \
+                 Request path: {:?} (type: {})",
+                req.path(),
+                type_name::<T>(),
+            );
+            future::err(ErrorInternalServerError(
+                "Missing expected request extension data",
+            ))
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::{cell::RefCell, rc::Rc};
+
+    use futures_util::TryFutureExt as _;
+
+    use super::*;
+    use crate::{
+        dev::Service,
+        http::{Method, StatusCode},
+        test::{init_service, TestRequest},
+        web, App, HttpMessage, HttpResponse,
+    };
+
+    #[actix_rt::test]
+    async fn req_data_extractor() {
+        let srv = init_service(
+            App::new()
+                .wrap_fn(|req, srv| {
+                    if req.method() == Method::POST {
+                        req.extensions_mut().insert(42u32);
+                    }
+
+                    srv.call(req)
+                })
+                .service(web::resource("/test").to(
+                    |req: HttpRequest, data: Option<ReqData<u32>>| {
+                        if req.method() != Method::POST {
+                            assert!(data.is_none());
+                        }
+
+                        if let Some(data) = data {
+                            assert_eq!(*data, 42);
+                            assert_eq!(
+                                Some(data.into_inner()),
+                                req.extensions().get::<u32>().copied()
+                            );
+                        }
+
+                        HttpResponse::Ok()
+                    },
+                )),
+        )
+        .await;
+
+        let req = TestRequest::get().uri("/test").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
+
+        let req = TestRequest::post().uri("/test").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
+    }
+
+    #[actix_rt::test]
+    async fn req_data_internal_mutability() {
+        let srv = init_service(
+            App::new()
+                .wrap_fn(|req, srv| {
+                    let data_before = Rc::new(RefCell::new(42u32));
+                    req.extensions_mut().insert(data_before);
+
+                    srv.call(req).map_ok(|res| {
+                        {
+                            let ext = res.request().extensions();
+                            let data_after = ext.get::<Rc<RefCell<u32>>>().unwrap();
+                            assert_eq!(*data_after.borrow(), 53u32);
+                        }
+
+                        res
+                    })
+                })
+                .default_service(web::to(|data: ReqData<Rc<RefCell<u32>>>| {
+                    assert_eq!(*data.borrow(), 42);
+                    *data.borrow_mut() += 11;
+                    assert_eq!(*data.borrow(), 53);
+
+                    HttpResponse::Ok()
+                })),
+        )
+        .await;
+
+        let req = TestRequest::get().uri("/test").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
+    }
+}
diff --git a/src/resource.rs b/src/resource.rs
index dd9b23012..944beeefa 100644
--- a/src/resource.rs
+++ b/src/resource.rs
@@ -1,25 +1,26 @@
 use std::cell::RefCell;
 use std::fmt;
 use std::future::Future;
-use std::pin::Pin;
 use std::rc::Rc;
-use std::task::{Context, Poll};
+use std::task::Poll;
 
 use actix_http::{Error, Extensions, Response};
 use actix_router::IntoPattern;
 use actix_service::boxed::{self, BoxService, BoxServiceFactory};
 use actix_service::{
-    apply, apply_fn_factory, IntoServiceFactory, Service, ServiceFactory, Transform,
+    apply, apply_fn_factory, fn_service, IntoServiceFactory, Service, ServiceFactory,
+    ServiceFactoryExt, Transform,
 };
-use futures_util::future::{ok, Either, LocalBoxFuture, Ready};
+use futures_core::future::LocalBoxFuture;
+use futures_util::future::join_all;
 
 use crate::data::Data;
 use crate::dev::{insert_slash, AppService, HttpServiceFactory, ResourceDef};
 use crate::extract::FromRequest;
 use crate::guard::Guard;
-use crate::handler::Factory;
+use crate::handler::Handler;
 use crate::responder::Responder;
-use crate::route::{CreateRouteService, Route, RouteService};
+use crate::route::{Route, RouteService};
 use crate::service::{ServiceRequest, ServiceResponse};
 
 type HttpService = BoxService<ServiceRequest, ServiceResponse, Error>;
@@ -52,9 +53,9 @@ pub struct Resource<T = ResourceEndpoint> {
     rdef: Vec<String>,
     name: Option<String>,
     routes: Vec<Route>,
-    data: Option<Extensions>,
+    app_data: Option<Extensions>,
     guards: Vec<Box<dyn Guard>>,
-    default: Rc<RefCell<Option<Rc<HttpNewService>>>>,
+    default: HttpNewService,
     factory_ref: Rc<RefCell<Option<ResourceFactory>>>,
 }
 
@@ -69,8 +70,10 @@ impl Resource {
             endpoint: ResourceEndpoint::new(fref.clone()),
             factory_ref: fref,
             guards: Vec::new(),
-            data: None,
-            default: Rc::new(RefCell::new(None)),
+            app_data: None,
+            default: boxed::factory(fn_service(|req: ServiceRequest| async {
+                Ok(req.into_response(Response::MethodNotAllowed().finish()))
+            })),
         }
     }
 }
@@ -78,8 +81,8 @@ impl Resource {
 impl<T> Resource<T>
 where
     T: ServiceFactory<
+        ServiceRequest,
         Config = (),
-        Request = ServiceRequest,
         Response = ServiceResponse,
         Error = Error,
         InitError = (),
@@ -200,10 +203,10 @@ where
     ///
     /// Data of different types from parent contexts will still be accessible.
     pub fn app_data<U: 'static>(mut self, data: U) -> Self {
-        if self.data.is_none() {
-            self.data = Some(Extensions::new());
-        }
-        self.data.as_mut().unwrap().insert(data);
+        self.app_data
+            .get_or_insert_with(Extensions::new)
+            .insert(data);
+
         self
     }
 
@@ -227,12 +230,12 @@ where
     /// # fn index(req: HttpRequest) -> HttpResponse { unimplemented!() }
     /// App::new().service(web::resource("/").route(web::route().to(index)));
     /// ```
-    pub fn to<F, I, R, U>(mut self, handler: F) -> Self
+    pub fn to<F, I, R>(mut self, handler: F) -> Self
     where
-        F: Factory<I, R, U>,
+        F: Handler<I, R>,
         I: FromRequest + 'static,
-        R: Future<Output = U> + 'static,
-        U: Responder + 'static,
+        R: Future + 'static,
+        R::Output: Responder + 'static,
     {
         self.routes.push(Route::new().to(handler));
         self
@@ -250,8 +253,8 @@ where
         mw: M,
     ) -> Resource<
         impl ServiceFactory<
+            ServiceRequest,
             Config = (),
-            Request = ServiceRequest,
             Response = ServiceResponse,
             Error = Error,
             InitError = (),
@@ -260,7 +263,7 @@ where
     where
         M: Transform<
             T::Service,
-            Request = ServiceRequest,
+            ServiceRequest,
             Response = ServiceResponse,
             Error = Error,
             InitError = (),
@@ -273,7 +276,7 @@ where
             guards: self.guards,
             routes: self.routes,
             default: self.default,
-            data: self.data,
+            app_data: self.app_data,
             factory_ref: self.factory_ref,
         }
     }
@@ -317,15 +320,15 @@ where
         mw: F,
     ) -> Resource<
         impl ServiceFactory<
+            ServiceRequest,
             Config = (),
-            Request = ServiceRequest,
             Response = ServiceResponse,
             Error = Error,
             InitError = (),
         >,
     >
     where
-        F: FnMut(ServiceRequest, &mut T::Service) -> R + Clone,
+        F: Fn(ServiceRequest, &T::Service) -> R + Clone,
         R: Future<Output = Result<ServiceResponse, Error>>,
     {
         Resource {
@@ -335,7 +338,7 @@ where
             guards: self.guards,
             routes: self.routes,
             default: self.default,
-            data: self.data,
+            app_data: self.app_data,
             factory_ref: self.factory_ref,
         }
     }
@@ -345,21 +348,20 @@ where
     /// default handler from `App` or `Scope`.
     pub fn default_service<F, U>(mut self, f: F) -> Self
     where
-        F: IntoServiceFactory<U>,
+        F: IntoServiceFactory<U, ServiceRequest>,
         U: ServiceFactory<
+                ServiceRequest,
                 Config = (),
-                Request = ServiceRequest,
                 Response = ServiceResponse,
                 Error = Error,
             > + 'static,
         U::InitError: fmt::Debug,
     {
         // create and configure default resource
-        self.default = Rc::new(RefCell::new(Some(Rc::new(boxed::factory(
-            f.into_factory().map_init_err(|e| {
-                log::error!("Can not construct default service: {:?}", e)
-            }),
-        )))));
+        self.default = boxed::factory(
+            f.into_factory()
+                .map_init_err(|e| log::error!("Can not construct default service: {:?}", e)),
+        );
 
         self
     }
@@ -368,8 +370,8 @@ where
 impl<T> HttpServiceFactory for Resource<T>
 where
     T: ServiceFactory<
+            ServiceRequest,
             Config = (),
-            Request = ServiceRequest,
             Response = ServiceResponse,
             Error = Error,
             InitError = (),
@@ -381,28 +383,26 @@ where
         } else {
             Some(std::mem::take(&mut self.guards))
         };
+
         let mut rdef = if config.is_root() || !self.rdef.is_empty() {
             ResourceDef::new(insert_slash(self.rdef.clone()))
         } else {
             ResourceDef::new(self.rdef.clone())
         };
+
         if let Some(ref name) = self.name {
             *rdef.name_mut() = name.clone();
         }
-        // custom app data storage
-        if let Some(ref mut ext) = self.data {
-            config.set_service_data(ext);
-        }
 
         config.register_service(rdef, guards, self, None)
     }
 }
 
-impl<T> IntoServiceFactory<T> for Resource<T>
+impl<T> IntoServiceFactory<T, ServiceRequest> for Resource<T>
 where
     T: ServiceFactory<
+        ServiceRequest,
         Config = (),
-        Request = ServiceRequest,
         Response = ServiceResponse,
         Error = Error,
         InitError = (),
@@ -411,7 +411,7 @@ where
     fn into_factory(self) -> T {
         *self.factory_ref.borrow_mut() = Some(ResourceFactory {
             routes: self.routes,
-            data: self.data.map(Rc::new),
+            app_data: self.app_data.map(Rc::new),
             default: self.default,
         });
 
@@ -421,139 +421,72 @@ where
 
 pub struct ResourceFactory {
     routes: Vec<Route>,
-    data: Option<Rc<Extensions>>,
-    default: Rc<RefCell<Option<Rc<HttpNewService>>>>,
+    app_data: Option<Rc<Extensions>>,
+    default: HttpNewService,
 }
 
-impl ServiceFactory for ResourceFactory {
-    type Config = ();
-    type Request = ServiceRequest;
+impl ServiceFactory<ServiceRequest> for ResourceFactory {
     type Response = ServiceResponse;
     type Error = Error;
-    type InitError = ();
+    type Config = ();
     type Service = ResourceService;
-    type Future = CreateResourceService;
+    type InitError = ();
+    type Future = LocalBoxFuture<'static, Result<Self::Service, Self::InitError>>;
 
     fn new_service(&self, _: ()) -> Self::Future {
-        let default_fut = if let Some(ref default) = *self.default.borrow() {
-            Some(default.new_service(()))
-        } else {
-            None
-        };
+        // construct default service factory future.
+        let default_fut = self.default.new_service(());
 
-        CreateResourceService {
-            fut: self
-                .routes
-                .iter()
-                .map(|route| CreateRouteServiceItem::Future(route.new_service(())))
-                .collect(),
-            data: self.data.clone(),
-            default: None,
-            default_fut,
-        }
-    }
-}
+        // construct route service factory futures
+        let factory_fut = join_all(self.routes.iter().map(|route| route.new_service(())));
 
-enum CreateRouteServiceItem {
-    Future(CreateRouteService),
-    Service(RouteService),
-}
+        let app_data = self.app_data.clone();
 
-pub struct CreateResourceService {
-    fut: Vec<CreateRouteServiceItem>,
-    data: Option<Rc<Extensions>>,
-    default: Option<HttpService>,
-    default_fut: Option<LocalBoxFuture<'static, Result<HttpService, ()>>>,
-}
+        Box::pin(async move {
+            let default = default_fut.await?;
+            let routes = factory_fut
+                .await
+                .into_iter()
+                .collect::<Result<Vec<_>, _>>()?;
 
-impl Future for CreateResourceService {
-    type Output = Result<ResourceService, ()>;
-
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let mut done = true;
-
-        if let Some(ref mut fut) = self.default_fut {
-            match Pin::new(fut).poll(cx)? {
-                Poll::Ready(default) => self.default = Some(default),
-                Poll::Pending => done = false,
-            }
-        }
-
-        // poll http services
-        for item in &mut self.fut {
-            match item {
-                CreateRouteServiceItem::Future(ref mut fut) => match Pin::new(fut)
-                    .poll(cx)?
-                {
-                    Poll::Ready(route) => *item = CreateRouteServiceItem::Service(route),
-                    Poll::Pending => {
-                        done = false;
-                    }
-                },
-                CreateRouteServiceItem::Service(_) => continue,
-            };
-        }
-
-        if done {
-            let routes = self
-                .fut
-                .drain(..)
-                .map(|item| match item {
-                    CreateRouteServiceItem::Service(service) => service,
-                    CreateRouteServiceItem::Future(_) => unreachable!(),
-                })
-                .collect();
-            Poll::Ready(Ok(ResourceService {
+            Ok(ResourceService {
+                app_data,
+                default,
                 routes,
-                data: self.data.clone(),
-                default: self.default.take(),
-            }))
-        } else {
-            Poll::Pending
-        }
+            })
+        })
     }
 }
 
 pub struct ResourceService {
     routes: Vec<RouteService>,
-    data: Option<Rc<Extensions>>,
-    default: Option<HttpService>,
+    app_data: Option<Rc<Extensions>>,
+    default: HttpService,
 }
 
-impl Service for ResourceService {
-    type Request = ServiceRequest;
+impl Service<ServiceRequest> for ResourceService {
     type Response = ServiceResponse;
     type Error = Error;
-    type Future = Either<
-        Ready<Result<ServiceResponse, Error>>,
-        LocalBoxFuture<'static, Result<ServiceResponse, Error>>,
-    >;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
+    actix_service::always_ready!();
 
-    fn call(&mut self, mut req: ServiceRequest) -> Self::Future {
-        for route in self.routes.iter_mut() {
+    fn call(&self, mut req: ServiceRequest) -> Self::Future {
+        for route in self.routes.iter() {
             if route.check(&mut req) {
-                if let Some(ref data) = self.data {
-                    req.add_data_container(data.clone());
+                if let Some(ref app_data) = self.app_data {
+                    req.add_data_container(app_data.clone());
                 }
-                return Either::Right(route.call(req));
+
+                return route.call(req);
             }
         }
-        if let Some(ref mut default) = self.default {
-            if let Some(ref data) = self.data {
-                req.add_data_container(data.clone());
-            }
-            Either::Right(default.call(req))
-        } else {
-            let req = req.into_parts().0;
-            Either::Left(ok(ServiceResponse::new(
-                req,
-                Response::MethodNotAllowed().finish(),
-            )))
+
+        if let Some(ref app_data) = self.app_data {
+            req.add_data_container(app_data.clone());
         }
+
+        self.default.call(req)
     }
 }
 
@@ -568,17 +501,16 @@ impl ResourceEndpoint {
     }
 }
 
-impl ServiceFactory for ResourceEndpoint {
-    type Config = ();
-    type Request = ServiceRequest;
+impl ServiceFactory<ServiceRequest> for ResourceEndpoint {
     type Response = ServiceResponse;
     type Error = Error;
-    type InitError = ();
+    type Config = ();
     type Service = ResourceService;
-    type Future = CreateResourceService;
+    type InitError = ();
+    type Future = LocalBoxFuture<'static, Result<Self::Service, Self::InitError>>;
 
     fn new_service(&self, _: ()) -> Self::Future {
-        self.factory.borrow_mut().as_mut().unwrap().new_service(())
+        self.factory.borrow().as_ref().unwrap().new_service(())
     }
 }
 
@@ -586,7 +518,7 @@ impl ServiceFactory for ResourceEndpoint {
 mod tests {
     use std::time::Duration;
 
-    use actix_rt::time::delay_for;
+    use actix_rt::time::sleep;
     use actix_service::Service;
     use futures_util::future::ok;
 
@@ -598,21 +530,20 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_middleware() {
-        let mut srv =
-            init_service(
-                App::new().service(
-                    web::resource("/test")
-                        .name("test")
-                        .wrap(DefaultHeaders::new().header(
-                            header::CONTENT_TYPE,
-                            HeaderValue::from_static("0001"),
-                        ))
-                        .route(web::get().to(HttpResponse::Ok)),
-                ),
-            )
-            .await;
+        let srv = init_service(
+            App::new().service(
+                web::resource("/test")
+                    .name("test")
+                    .wrap(
+                        DefaultHeaders::new()
+                            .header(header::CONTENT_TYPE, HeaderValue::from_static("0001")),
+                    )
+                    .route(web::get().to(HttpResponse::Ok)),
+            ),
+        )
+        .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
@@ -622,7 +553,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_middleware_fn() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::resource("/test")
                     .wrap_fn(|req, srv| {
@@ -642,7 +573,7 @@ mod tests {
         )
         .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
@@ -652,20 +583,19 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_to() {
-        let mut srv =
-            init_service(App::new().service(web::resource("/test").to(|| async {
-                delay_for(Duration::from_millis(100)).await;
-                Ok::<_, Error>(HttpResponse::Ok())
-            })))
-            .await;
+        let srv = init_service(App::new().service(web::resource("/test").to(|| async {
+            sleep(Duration::from_millis(100)).await;
+            Ok::<_, Error>(HttpResponse::Ok())
+        })))
+        .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 
     #[actix_rt::test]
     async fn test_pattern() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::resource(["/test", "/test2"])
                     .to(|| async { Ok::<_, Error>(HttpResponse::Ok()) }),
@@ -673,16 +603,16 @@ mod tests {
         )
         .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         let req = TestRequest::with_uri("/test2").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 
     #[actix_rt::test]
     async fn test_default_resource() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .service(web::resource("/test").route(web::get().to(HttpResponse::Ok)))
                 .default_service(|r: ServiceRequest| {
@@ -691,16 +621,16 @@ mod tests {
         )
         .await;
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
         let req = TestRequest::with_uri("/test")
             .method(Method::POST)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::METHOD_NOT_ALLOWED);
 
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::resource("/test")
                     .route(web::get().to(HttpResponse::Ok))
@@ -712,19 +642,19 @@ mod tests {
         .await;
 
         let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
         let req = TestRequest::with_uri("/test")
             .method(Method::POST)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
     }
 
     #[actix_rt::test]
     async fn test_resource_guards() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .service(
                     web::resource("/test/{p}")
@@ -747,25 +677,25 @@ mod tests {
         let req = TestRequest::with_uri("/test/it")
             .method(Method::GET)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
         let req = TestRequest::with_uri("/test/it")
             .method(Method::PUT)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::CREATED);
 
         let req = TestRequest::with_uri("/test/it")
             .method(Method::DELETE)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::NO_CONTENT);
     }
 
     #[actix_rt::test]
     async fn test_data() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .data(1.0f64)
                 .data(1usize)
@@ -791,13 +721,13 @@ mod tests {
         .await;
 
         let req = TestRequest::get().uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 
     #[actix_rt::test]
     async fn test_data_default_service() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().data(1usize).service(
                 web::resource("/test")
                     .data(10usize)
@@ -810,7 +740,7 @@ mod tests {
         .await;
 
         let req = TestRequest::get().uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 }
diff --git a/src/responder.rs b/src/responder.rs
index fc80831b8..92945cdaa 100644
--- a/src/responder.rs
+++ b/src/responder.rs
@@ -1,43 +1,29 @@
-use std::convert::TryFrom;
-use std::future::Future;
-use std::marker::PhantomData;
-use std::pin::Pin;
-use std::task::{Context, Poll};
+use std::fmt;
 
-use actix_http::error::InternalError;
-use actix_http::http::{
-    header::IntoHeaderValue, Error as HttpError, HeaderMap, HeaderName, StatusCode,
+use actix_http::{
+    error::InternalError,
+    http::{header::IntoHeaderPair, Error as HttpError, HeaderMap, StatusCode},
+    ResponseBuilder,
 };
-use actix_http::{Error, Response, ResponseBuilder};
 use bytes::{Bytes, BytesMut};
-use futures_util::future::{err, ok, Either as EitherFuture, Ready};
-use futures_util::ready;
-use pin_project::pin_project;
 
-use crate::request::HttpRequest;
+use crate::{Error, HttpRequest, HttpResponse};
 
-/// Trait implemented by types that can be converted to a http response.
+/// Trait implemented by types that can be converted to an HTTP response.
 ///
-/// Types that implement this trait can be used as the return type of a handler.
+/// Any types that implement this trait can be used in the return type of a handler.
 pub trait Responder {
-    /// The associated error which can be returned.
-    type Error: Into<Error>;
-
-    /// The future response value.
-    type Future: Future<Output = Result<Response, Self::Error>>;
-
-    /// Convert itself to `AsyncResult` or `Error`.
-    fn respond_to(self, req: &HttpRequest) -> Self::Future;
+    /// Convert self to `HttpResponse`.
+    fn respond_to(self, req: &HttpRequest) -> HttpResponse;
 
     /// Override a status code for a Responder.
     ///
     /// ```rust
-    /// use actix_web::{HttpRequest, Responder, http::StatusCode};
+    /// use actix_web::{http::StatusCode, HttpRequest, Responder};
     ///
     /// fn index(req: HttpRequest) -> impl Responder {
     ///     "Welcome!".with_status(StatusCode::OK)
     /// }
-    /// # fn main() {}
     /// ```
     fn with_status(self, status: StatusCode) -> CustomResponder<Self>
     where
@@ -46,7 +32,9 @@ pub trait Responder {
         CustomResponder::new(self).with_status(status)
     }
 
-    /// Add header to the Responder's response.
+    /// Insert header to the final response.
+    ///
+    /// Overrides other headers with the same name.
     ///
     /// ```rust
     /// use actix_web::{web, HttpRequest, Responder};
@@ -58,47 +46,31 @@ pub trait Responder {
     /// }
     ///
     /// fn index(req: HttpRequest) -> impl Responder {
-    ///     web::Json(
-    ///         MyObj{name: "Name".to_string()}
-    ///     )
-    ///     .with_header("x-version", "1.2.3")
+    ///     web::Json(MyObj { name: "Name".to_owned() })
+    ///         .with_header(("x-version", "1.2.3"))
     /// }
-    /// # fn main() {}
     /// ```
-    fn with_header<K, V>(self, key: K, value: V) -> CustomResponder<Self>
+    fn with_header<H>(self, header: H) -> CustomResponder<Self>
     where
         Self: Sized,
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
+        H: IntoHeaderPair,
     {
-        CustomResponder::new(self).with_header(key, value)
+        CustomResponder::new(self).with_header(header)
     }
 }
 
-impl Responder for Response {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
+impl Responder for HttpResponse {
     #[inline]
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        ok(self)
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        self
     }
 }
 
-impl<T> Responder for Option<T>
-where
-    T: Responder,
-{
-    type Error = T::Error;
-    type Future = EitherFuture<T::Future, Ready<Result<Response, T::Error>>>;
-
-    fn respond_to(self, req: &HttpRequest) -> Self::Future {
+impl<T: Responder> Responder for Option<T> {
+    fn respond_to(self, req: &HttpRequest) -> HttpResponse {
         match self {
-            Some(t) => EitherFuture::Left(t.respond_to(req)),
-            None => {
-                EitherFuture::Right(ok(Response::build(StatusCode::NOT_FOUND).finish()))
-            }
+            Some(t) => t.respond_to(req),
+            None => HttpResponse::build(StatusCode::NOT_FOUND).finish(),
         }
     }
 }
@@ -108,113 +80,78 @@ where
     T: Responder,
     E: Into<Error>,
 {
-    type Error = Error;
-    type Future = EitherFuture<
-        ResponseFuture<T::Future, T::Error>,
-        Ready<Result<Response, Error>>,
-    >;
-
-    fn respond_to(self, req: &HttpRequest) -> Self::Future {
+    fn respond_to(self, req: &HttpRequest) -> HttpResponse {
         match self {
-            Ok(val) => EitherFuture::Left(ResponseFuture::new(val.respond_to(req))),
-            Err(e) => EitherFuture::Right(err(e.into())),
+            Ok(val) => val.respond_to(req),
+            Err(e) => HttpResponse::from_error(e.into()),
         }
     }
 }
 
 impl Responder for ResponseBuilder {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
     #[inline]
-    fn respond_to(mut self, _: &HttpRequest) -> Self::Future {
-        ok(self.finish())
+    fn respond_to(mut self, _: &HttpRequest) -> HttpResponse {
+        self.finish()
     }
 }
 
-impl<T> Responder for (T, StatusCode)
-where
-    T: Responder,
-{
-    type Error = T::Error;
-    type Future = CustomResponderFut<T>;
-
-    fn respond_to(self, req: &HttpRequest) -> Self::Future {
-        CustomResponderFut {
-            fut: self.0.respond_to(req),
-            status: Some(self.1),
-            headers: None,
-        }
+impl<T: Responder> Responder for (T, StatusCode) {
+    fn respond_to(self, req: &HttpRequest) -> HttpResponse {
+        let mut res = self.0.respond_to(req);
+        *res.status_mut() = self.1;
+        res
     }
 }
 
 impl Responder for &'static str {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        ok(Response::build(StatusCode::OK)
-            .content_type("text/plain; charset=utf-8")
-            .body(self))
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        HttpResponse::Ok()
+            .content_type(mime::TEXT_PLAIN_UTF_8)
+            .body(self)
     }
 }
 
 impl Responder for &'static [u8] {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        ok(Response::build(StatusCode::OK)
-            .content_type("application/octet-stream")
-            .body(self))
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        HttpResponse::Ok()
+            .content_type(mime::APPLICATION_OCTET_STREAM)
+            .body(self)
     }
 }
 
 impl Responder for String {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        ok(Response::build(StatusCode::OK)
-            .content_type("text/plain; charset=utf-8")
-            .body(self))
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        HttpResponse::Ok()
+            .content_type(mime::TEXT_PLAIN_UTF_8)
+            .body(self)
     }
 }
 
 impl<'a> Responder for &'a String {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        ok(Response::build(StatusCode::OK)
-            .content_type("text/plain; charset=utf-8")
-            .body(self))
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        HttpResponse::Ok()
+            .content_type(mime::TEXT_PLAIN_UTF_8)
+            .body(self)
     }
 }
 
 impl Responder for Bytes {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        ok(Response::build(StatusCode::OK)
-            .content_type("application/octet-stream")
-            .body(self))
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        HttpResponse::Ok()
+            .content_type(mime::APPLICATION_OCTET_STREAM)
+            .body(self)
     }
 }
 
 impl Responder for BytesMut {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        ok(Response::build(StatusCode::OK)
-            .content_type("application/octet-stream")
-            .body(self))
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        HttpResponse::Ok()
+            .content_type(mime::APPLICATION_OCTET_STREAM)
+            .body(self)
     }
 }
 
-/// Allows to override status code and headers for a responder.
+/// Allows overriding status code and headers for a responder.
 pub struct CustomResponder<T> {
     responder: T,
     status: Option<StatusCode>,
@@ -240,14 +177,15 @@ impl<T: Responder> CustomResponder<T> {
     /// fn index(req: HttpRequest) -> impl Responder {
     ///     "Welcome!".with_status(StatusCode::OK)
     /// }
-    /// # fn main() {}
     /// ```
     pub fn with_status(mut self, status: StatusCode) -> Self {
         self.status = Some(status);
         self
     }
 
-    /// Add header to the Responder's response.
+    /// Insert header to the final response.
+    ///
+    /// Overrides other headers with the same name.
     ///
     /// ```rust
     /// use actix_web::{web, HttpRequest, Responder};
@@ -259,193 +197,53 @@ impl<T: Responder> CustomResponder<T> {
     /// }
     ///
     /// fn index(req: HttpRequest) -> impl Responder {
-    ///     web::Json(
-    ///         MyObj{name: "Name".to_string()}
-    ///     )
-    ///     .with_header("x-version", "1.2.3")
+    ///     web::Json(MyObj { name: "Name".to_string() })
+    ///         .with_header(("x-version", "1.2.3"))
+    ///         .with_header(("x-version", "1.2.3"))
     /// }
-    /// # fn main() {}
     /// ```
-    pub fn with_header<K, V>(mut self, key: K, value: V) -> Self
+    pub fn with_header<H>(mut self, header: H) -> Self
     where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
+        H: IntoHeaderPair,
     {
         if self.headers.is_none() {
             self.headers = Some(HeaderMap::new());
         }
 
-        match HeaderName::try_from(key) {
-            Ok(key) => match value.try_into() {
-                Ok(value) => {
-                    self.headers.as_mut().unwrap().append(key, value);
-                }
-                Err(e) => self.error = Some(e.into()),
-            },
+        match header.try_into_header_pair() {
+            Ok((key, value)) => self.headers.as_mut().unwrap().append(key, value),
             Err(e) => self.error = Some(e.into()),
         };
+
         self
     }
 }
 
 impl<T: Responder> Responder for CustomResponder<T> {
-    type Error = T::Error;
-    type Future = CustomResponderFut<T>;
+    fn respond_to(self, req: &HttpRequest) -> HttpResponse {
+        let mut res = self.responder.respond_to(req);
 
-    fn respond_to(self, req: &HttpRequest) -> Self::Future {
-        CustomResponderFut {
-            fut: self.responder.respond_to(req),
-            status: self.status,
-            headers: self.headers,
-        }
-    }
-}
-
-#[pin_project]
-pub struct CustomResponderFut<T: Responder> {
-    #[pin]
-    fut: T::Future,
-    status: Option<StatusCode>,
-    headers: Option<HeaderMap>,
-}
-
-impl<T: Responder> Future for CustomResponderFut<T> {
-    type Output = Result<Response, T::Error>;
-
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.project();
-
-        let mut res = match ready!(this.fut.poll(cx)) {
-            Ok(res) => res,
-            Err(e) => return Poll::Ready(Err(e)),
-        };
-        if let Some(status) = this.status.take() {
+        if let Some(status) = self.status {
             *res.status_mut() = status;
         }
-        if let Some(ref headers) = this.headers {
+
+        if let Some(ref headers) = self.headers {
             for (k, v) in headers {
+                // TODO: before v4, decide if this should be append instead
                 res.headers_mut().insert(k.clone(), v.clone());
             }
         }
-        Poll::Ready(Ok(res))
-    }
-}
 
-/// Combines two different responder types into a single type
-///
-/// ```rust
-/// use actix_web::{Either, Error, HttpResponse};
-///
-/// type RegisterResult = Either<HttpResponse, Result<HttpResponse, Error>>;
-///
-/// fn index() -> RegisterResult {
-///     if is_a_variant() {
-///         // <- choose left variant
-///         Either::A(HttpResponse::BadRequest().body("Bad data"))
-///     } else {
-///         Either::B(
-///             // <- Right variant
-///             Ok(HttpResponse::Ok()
-///                 .content_type("text/html")
-///                 .body("Hello!"))
-///         )
-///     }
-/// }
-/// # fn is_a_variant() -> bool { true }
-/// # fn main() {}
-/// ```
-#[derive(Debug, PartialEq)]
-pub enum Either<A, B> {
-    /// First branch of the type
-    A(A),
-    /// Second branch of the type
-    B(B),
-}
-
-impl<A, B> Responder for Either<A, B>
-where
-    A: Responder,
-    B: Responder,
-{
-    type Error = Error;
-    type Future = EitherResponder<A, B>;
-
-    fn respond_to(self, req: &HttpRequest) -> Self::Future {
-        match self {
-            Either::A(a) => EitherResponder::A(a.respond_to(req)),
-            Either::B(b) => EitherResponder::B(b.respond_to(req)),
-        }
-    }
-}
-
-#[pin_project(project = EitherResponderProj)]
-pub enum EitherResponder<A, B>
-where
-    A: Responder,
-    B: Responder,
-{
-    A(#[pin] A::Future),
-    B(#[pin] B::Future),
-}
-
-impl<A, B> Future for EitherResponder<A, B>
-where
-    A: Responder,
-    B: Responder,
-{
-    type Output = Result<Response, Error>;
-
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        match self.project() {
-            EitherResponderProj::A(fut) => {
-                Poll::Ready(ready!(fut.poll(cx)).map_err(|e| e.into()))
-            }
-            EitherResponderProj::B(fut) => {
-                Poll::Ready(ready!(fut.poll(cx).map_err(|e| e.into())))
-            }
-        }
+        res
     }
 }
 
 impl<T> Responder for InternalError<T>
 where
-    T: std::fmt::Debug + std::fmt::Display + 'static,
+    T: fmt::Debug + fmt::Display + 'static,
 {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        let err: Error = self.into();
-        ok(err.into())
-    }
-}
-
-#[pin_project]
-pub struct ResponseFuture<T, E> {
-    #[pin]
-    fut: T,
-    _t: PhantomData<E>,
-}
-
-impl<T, E> ResponseFuture<T, E> {
-    pub fn new(fut: T) -> Self {
-        ResponseFuture {
-            fut,
-            _t: PhantomData,
-        }
-    }
-}
-
-impl<T, E> Future for ResponseFuture<T, E>
-where
-    T: Future<Output = Result<Response, E>>,
-    E: Into<Error>,
-{
-    type Output = Result<Response, Error>;
-
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        Poll::Ready(ready!(self.project().fut.poll(cx)).map_err(|e| e.into()))
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        HttpResponse::from_error(self.into())
     }
 }
 
@@ -458,15 +256,13 @@ pub(crate) mod tests {
     use crate::dev::{Body, ResponseBody};
     use crate::http::{header::CONTENT_TYPE, HeaderValue, StatusCode};
     use crate::test::{init_service, TestRequest};
-    use crate::{error, web, App, HttpResponse};
+    use crate::{error, web, App};
 
     #[actix_rt::test]
     async fn test_option_responder() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
-                .service(
-                    web::resource("/none").to(|| async { Option::<&'static str>::None }),
-                )
+                .service(web::resource("/none").to(|| async { Option::<&'static str>::None }))
                 .service(web::resource("/some").to(|| async { Some("some") })),
         )
         .await;
@@ -517,7 +313,7 @@ pub(crate) mod tests {
     async fn test_responder() {
         let req = TestRequest::default().to_http_request();
 
-        let resp: HttpResponse = "test".respond_to(&req).await.unwrap();
+        let resp = "test".respond_to(&req);
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(resp.body().bin_ref(), b"test");
         assert_eq!(
@@ -525,7 +321,7 @@ pub(crate) mod tests {
             HeaderValue::from_static("text/plain; charset=utf-8")
         );
 
-        let resp: HttpResponse = b"test".respond_to(&req).await.unwrap();
+        let resp = b"test".respond_to(&req);
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(resp.body().bin_ref(), b"test");
         assert_eq!(
@@ -533,7 +329,7 @@ pub(crate) mod tests {
             HeaderValue::from_static("application/octet-stream")
         );
 
-        let resp: HttpResponse = "test".to_string().respond_to(&req).await.unwrap();
+        let resp = "test".to_string().respond_to(&req);
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(resp.body().bin_ref(), b"test");
         assert_eq!(
@@ -541,7 +337,7 @@ pub(crate) mod tests {
             HeaderValue::from_static("text/plain; charset=utf-8")
         );
 
-        let resp: HttpResponse = (&"test".to_string()).respond_to(&req).await.unwrap();
+        let resp = (&"test".to_string()).respond_to(&req);
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(resp.body().bin_ref(), b"test");
         assert_eq!(
@@ -549,8 +345,7 @@ pub(crate) mod tests {
             HeaderValue::from_static("text/plain; charset=utf-8")
         );
 
-        let resp: HttpResponse =
-            Bytes::from_static(b"test").respond_to(&req).await.unwrap();
+        let resp = Bytes::from_static(b"test").respond_to(&req);
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(resp.body().bin_ref(), b"test");
         assert_eq!(
@@ -558,10 +353,7 @@ pub(crate) mod tests {
             HeaderValue::from_static("application/octet-stream")
         );
 
-        let resp: HttpResponse = BytesMut::from(b"test".as_ref())
-            .respond_to(&req)
-            .await
-            .unwrap();
+        let resp = BytesMut::from(b"test".as_ref()).respond_to(&req);
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(resp.body().bin_ref(), b"test");
         assert_eq!(
@@ -570,11 +362,7 @@ pub(crate) mod tests {
         );
 
         // InternalError
-        let resp: HttpResponse =
-            error::InternalError::new("err", StatusCode::BAD_REQUEST)
-                .respond_to(&req)
-                .await
-                .unwrap();
+        let resp = error::InternalError::new("err", StatusCode::BAD_REQUEST).respond_to(&req);
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
     }
 
@@ -583,10 +371,7 @@ pub(crate) mod tests {
         let req = TestRequest::default().to_http_request();
 
         // Result<I, E>
-        let resp: HttpResponse = Ok::<_, Error>("test".to_string())
-            .respond_to(&req)
-            .await
-            .unwrap();
+        let resp = Ok::<_, Error>("test".to_string()).respond_to(&req);
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(resp.body().bin_ref(), b"test");
         assert_eq!(
@@ -594,11 +379,10 @@ pub(crate) mod tests {
             HeaderValue::from_static("text/plain; charset=utf-8")
         );
 
-        let res =
-            Err::<String, _>(error::InternalError::new("err", StatusCode::BAD_REQUEST))
-                .respond_to(&req)
-                .await;
-        assert!(res.is_err());
+        let res = Err::<String, _>(error::InternalError::new("err", StatusCode::BAD_REQUEST))
+            .respond_to(&req);
+
+        assert_eq!(res.status(), StatusCode::BAD_REQUEST);
     }
 
     #[actix_rt::test]
@@ -607,18 +391,15 @@ pub(crate) mod tests {
         let res = "test"
             .to_string()
             .with_status(StatusCode::BAD_REQUEST)
-            .respond_to(&req)
-            .await
-            .unwrap();
+            .respond_to(&req);
+
         assert_eq!(res.status(), StatusCode::BAD_REQUEST);
         assert_eq!(res.body().bin_ref(), b"test");
 
         let res = "test"
             .to_string()
-            .with_header("content-type", "json")
-            .respond_to(&req)
-            .await
-            .unwrap();
+            .with_header(("content-type", "json"))
+            .respond_to(&req);
 
         assert_eq!(res.status(), StatusCode::OK);
         assert_eq!(res.body().bin_ref(), b"test");
@@ -631,24 +412,19 @@ pub(crate) mod tests {
     #[actix_rt::test]
     async fn test_tuple_responder_with_status_code() {
         let req = TestRequest::default().to_http_request();
-        let res = ("test".to_string(), StatusCode::BAD_REQUEST)
-            .respond_to(&req)
-            .await
-            .unwrap();
+        let res = ("test".to_string(), StatusCode::BAD_REQUEST).respond_to(&req);
         assert_eq!(res.status(), StatusCode::BAD_REQUEST);
         assert_eq!(res.body().bin_ref(), b"test");
 
         let req = TestRequest::default().to_http_request();
         let res = ("test".to_string(), StatusCode::OK)
-            .with_header("content-type", "json")
-            .respond_to(&req)
-            .await
-            .unwrap();
+            .with_header((CONTENT_TYPE, mime::APPLICATION_JSON))
+            .respond_to(&req);
         assert_eq!(res.status(), StatusCode::OK);
         assert_eq!(res.body().bin_ref(), b"test");
         assert_eq!(
             res.headers().get(CONTENT_TYPE).unwrap(),
-            HeaderValue::from_static("json")
+            HeaderValue::from_static("application/json")
         );
     }
 }
diff --git a/src/rmap.rs b/src/rmap.rs
index 05c1f3f15..3c8805d57 100644
--- a/src/rmap.rs
+++ b/src/rmap.rs
@@ -2,7 +2,7 @@ use std::cell::RefCell;
 use std::rc::{Rc, Weak};
 
 use actix_router::ResourceDef;
-use fxhash::FxHashMap;
+use ahash::AHashMap;
 use url::Url;
 
 use crate::error::UrlGenerationError;
@@ -12,7 +12,7 @@ use crate::request::HttpRequest;
 pub struct ResourceMap {
     root: ResourceDef,
     parent: RefCell<Weak<ResourceMap>>,
-    named: FxHashMap<String, ResourceDef>,
+    named: AHashMap<String, ResourceDef>,
     patterns: Vec<(ResourceDef, Option<Rc<ResourceMap>>)>,
 }
 
@@ -21,7 +21,7 @@ impl ResourceMap {
         ResourceMap {
             root,
             parent: RefCell::new(Weak::new()),
-            named: FxHashMap::default(),
+            named: AHashMap::default(),
             patterns: Vec::new(),
         }
     }
@@ -86,7 +86,7 @@ impl ResourceMap {
                 if let Some(plen) = pattern.is_prefix_match(path) {
                     return rmap.has_resource(&path[plen..]);
                 }
-            } else if pattern.is_match(path) {
+            } else if pattern.is_match(path) || pattern.pattern() == "" && path == "/" {
                 return true;
             }
         }
diff --git a/src/route.rs b/src/route.rs
index 129a67332..b6b2482cd 100644
--- a/src/route.rs
+++ b/src/route.rs
@@ -1,3 +1,5 @@
+#![allow(clippy::rc_buffer)] // inner value is mutated before being shared (`Rc::get_mut`)
+
 use std::future::Future;
 use std::pin::Pin;
 use std::rc::Rc;
@@ -9,29 +11,29 @@ use futures_util::future::{ready, FutureExt, LocalBoxFuture};
 
 use crate::extract::FromRequest;
 use crate::guard::{self, Guard};
-use crate::handler::{Extract, Factory, Handler};
+use crate::handler::{Handler, HandlerService};
 use crate::responder::Responder;
 use crate::service::{ServiceRequest, ServiceResponse};
 use crate::HttpResponse;
 
-type BoxedRouteService<Req, Res> = Box<
+type BoxedRouteService = Box<
     dyn Service<
-        Request = Req,
-        Response = Res,
+        ServiceRequest,
+        Response = ServiceResponse,
         Error = Error,
-        Future = LocalBoxFuture<'static, Result<Res, Error>>,
+        Future = LocalBoxFuture<'static, Result<ServiceResponse, Error>>,
     >,
 >;
 
-type BoxedRouteNewService<Req, Res> = Box<
+type BoxedRouteNewService = Box<
     dyn ServiceFactory<
+        ServiceRequest,
         Config = (),
-        Request = Req,
-        Response = Res,
+        Response = ServiceResponse,
         Error = Error,
         InitError = (),
-        Service = BoxedRouteService<Req, Res>,
-        Future = LocalBoxFuture<'static, Result<BoxedRouteService<Req, Res>, ()>>,
+        Service = BoxedRouteService,
+        Future = LocalBoxFuture<'static, Result<BoxedRouteService, ()>>,
     >,
 >;
 
@@ -40,7 +42,7 @@ type BoxedRouteNewService<Req, Res> = Box<
 /// Route uses builder-like pattern for configuration.
 /// If handler is not explicitly set, default *404 Not Found* handler is used.
 pub struct Route {
-    service: BoxedRouteNewService<ServiceRequest, ServiceResponse>,
+    service: BoxedRouteNewService,
     guards: Rc<Vec<Box<dyn Guard>>>,
 }
 
@@ -49,9 +51,9 @@ impl Route {
     #[allow(clippy::new_without_default)]
     pub fn new() -> Route {
         Route {
-            service: Box::new(RouteNewService::new(Extract::new(Handler::new(|| {
+            service: Box::new(RouteNewService::new(HandlerService::new(|| {
                 ready(HttpResponse::NotFound())
-            })))),
+            }))),
             guards: Rc::new(Vec::new()),
         }
     }
@@ -61,9 +63,8 @@ impl Route {
     }
 }
 
-impl ServiceFactory for Route {
+impl ServiceFactory<ServiceRequest> for Route {
     type Config = ();
-    type Request = ServiceRequest;
     type Response = ServiceResponse;
     type Error = Error;
     type InitError = ();
@@ -78,15 +79,8 @@ impl ServiceFactory for Route {
     }
 }
 
-type RouteFuture = LocalBoxFuture<
-    'static,
-    Result<BoxedRouteService<ServiceRequest, ServiceResponse>, ()>,
->;
-
-#[pin_project::pin_project]
 pub struct CreateRouteService {
-    #[pin]
-    fut: RouteFuture,
+    fut: LocalBoxFuture<'static, Result<BoxedRouteService, ()>>,
     guards: Rc<Vec<Box<dyn Guard>>>,
 }
 
@@ -94,9 +88,9 @@ impl Future for CreateRouteService {
     type Output = Result<RouteService, ()>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.project();
+        let this = self.get_mut();
 
-        match this.fut.poll(cx)? {
+        match this.fut.as_mut().poll(cx)? {
             Poll::Ready(service) => Poll::Ready(Ok(RouteService {
                 service,
                 guards: this.guards.clone(),
@@ -107,7 +101,7 @@ impl Future for CreateRouteService {
 }
 
 pub struct RouteService {
-    service: BoxedRouteService<ServiceRequest, ServiceResponse>,
+    service: BoxedRouteService,
     guards: Rc<Vec<Box<dyn Guard>>>,
 }
 
@@ -122,18 +116,17 @@ impl RouteService {
     }
 }
 
-impl Service for RouteService {
-    type Request = ServiceRequest;
+impl Service<ServiceRequest> for RouteService {
     type Response = ServiceResponse;
     type Error = Error;
     type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         self.service.poll_ready(cx)
     }
 
-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
-        self.service.call(req).boxed_local()
+    fn call(&self, req: ServiceRequest) -> Self::Future {
+        self.service.call(req)
     }
 }
 
@@ -224,61 +217,49 @@ impl Route {
     ///     );
     /// }
     /// ```
-    pub fn to<F, T, R, U>(mut self, handler: F) -> Self
+    pub fn to<F, T, R>(mut self, handler: F) -> Self
     where
-        F: Factory<T, R, U>,
+        F: Handler<T, R>,
         T: FromRequest + 'static,
-        R: Future<Output = U> + 'static,
-        U: Responder + 'static,
+        R: Future + 'static,
+        R::Output: Responder + 'static,
     {
-        self.service =
-            Box::new(RouteNewService::new(Extract::new(Handler::new(handler))));
+        self.service = Box::new(RouteNewService::new(HandlerService::new(handler)));
         self
     }
 }
 
 struct RouteNewService<T>
 where
-    T: ServiceFactory<Request = ServiceRequest, Error = (Error, ServiceRequest)>,
+    T: ServiceFactory<ServiceRequest, Error = Error>,
 {
     service: T,
 }
 
 impl<T> RouteNewService<T>
 where
-    T: ServiceFactory<
-        Config = (),
-        Request = ServiceRequest,
-        Response = ServiceResponse,
-        Error = (Error, ServiceRequest),
-    >,
+    T: ServiceFactory<ServiceRequest, Config = (), Response = ServiceResponse, Error = Error>,
     T::Future: 'static,
     T::Service: 'static,
-    <T::Service as Service>::Future: 'static,
+    <T::Service as Service<ServiceRequest>>::Future: 'static,
 {
     pub fn new(service: T) -> Self {
         RouteNewService { service }
     }
 }
 
-impl<T> ServiceFactory for RouteNewService<T>
+impl<T> ServiceFactory<ServiceRequest> for RouteNewService<T>
 where
-    T: ServiceFactory<
-        Config = (),
-        Request = ServiceRequest,
-        Response = ServiceResponse,
-        Error = (Error, ServiceRequest),
-    >,
+    T: ServiceFactory<ServiceRequest, Config = (), Response = ServiceResponse, Error = Error>,
     T::Future: 'static,
     T::Service: 'static,
-    <T::Service as Service>::Future: 'static,
+    <T::Service as Service<ServiceRequest>>::Future: 'static,
 {
-    type Config = ();
-    type Request = ServiceRequest;
     type Response = ServiceResponse;
     type Error = Error;
+    type Config = ();
+    type Service = BoxedRouteService;
     type InitError = ();
-    type Service = BoxedRouteService<ServiceRequest, Self::Response>;
     type Future = LocalBoxFuture<'static, Result<Self::Service, Self::InitError>>;
 
     fn new_service(&self, _: ()) -> Self::Future {
@@ -286,8 +267,7 @@ where
             .new_service(())
             .map(|result| match result {
                 Ok(service) => {
-                    let service: BoxedRouteService<_, _> =
-                        Box::new(RouteServiceWrapper { service });
+                    let service = Box::new(RouteServiceWrapper { service }) as _;
                     Ok(service)
                 }
                 Err(_) => Err(()),
@@ -296,46 +276,25 @@ where
     }
 }
 
-struct RouteServiceWrapper<T: Service> {
+struct RouteServiceWrapper<T: Service<ServiceRequest>> {
     service: T,
 }
 
-impl<T> Service for RouteServiceWrapper<T>
+impl<T> Service<ServiceRequest> for RouteServiceWrapper<T>
 where
     T::Future: 'static,
-    T: Service<
-        Request = ServiceRequest,
-        Response = ServiceResponse,
-        Error = (Error, ServiceRequest),
-    >,
+    T: Service<ServiceRequest, Response = ServiceResponse, Error = Error>,
 {
-    type Request = ServiceRequest;
     type Response = ServiceResponse;
     type Error = Error;
     type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.service.poll_ready(cx).map_err(|(e, _)| e)
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        self.service.poll_ready(cx)
     }
 
-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
-        // let mut fut = self.service.call(req);
-        self.service
-            .call(req)
-            .map(|res| match res {
-                Ok(res) => Ok(res),
-                Err((err, req)) => Ok(req.error_response(err)),
-            })
-            .boxed_local()
-
-        // match fut.poll() {
-        //     Poll::Ready(Ok(res)) => Either::Left(ok(res)),
-        //     Poll::Ready(Err((e, req))) => Either::Left(ok(req.error_response(e))),
-        //     Poll::Pending => Either::Right(Box::new(fut.then(|res| match res {
-        //         Ok(res) => Ok(res),
-        //         Err((err, req)) => Ok(req.error_response(err)),
-        //     }))),
-        // }
+    fn call(&self, req: ServiceRequest) -> Self::Future {
+        Box::pin(self.service.call(req))
     }
 }
 
@@ -343,7 +302,7 @@ where
 mod tests {
     use std::time::Duration;
 
-    use actix_rt::time::delay_for;
+    use actix_rt::time::sleep;
     use bytes::Bytes;
     use serde_derive::Serialize;
 
@@ -358,7 +317,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_route() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .service(
                     web::resource("/test")
@@ -367,16 +326,16 @@ mod tests {
                             Err::<HttpResponse, _>(error::ErrorBadRequest("err"))
                         }))
                         .route(web::post().to(|| async {
-                            delay_for(Duration::from_millis(100)).await;
+                            sleep(Duration::from_millis(100)).await;
                             Ok::<_, ()>(HttpResponse::Created())
                         }))
                         .route(web::delete().to(|| async {
-                            delay_for(Duration::from_millis(100)).await;
+                            sleep(Duration::from_millis(100)).await;
                             Err::<HttpResponse, _>(error::ErrorBadRequest("err"))
                         })),
                 )
                 .service(web::resource("/json").route(web::get().to(|| async {
-                    delay_for(Duration::from_millis(25)).await;
+                    sleep(Duration::from_millis(25)).await;
                     web::Json(MyObject {
                         name: "test".to_string(),
                     })
@@ -387,35 +346,35 @@ mod tests {
         let req = TestRequest::with_uri("/test")
             .method(Method::GET)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
         let req = TestRequest::with_uri("/test")
             .method(Method::POST)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::CREATED);
 
         let req = TestRequest::with_uri("/test")
             .method(Method::PUT)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
 
         let req = TestRequest::with_uri("/test")
             .method(Method::DELETE)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
 
         let req = TestRequest::with_uri("/test")
             .method(Method::HEAD)
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::METHOD_NOT_ALLOWED);
 
         let req = TestRequest::with_uri("/json").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
         let body = read_body(resp).await;
diff --git a/src/scope.rs b/src/scope.rs
index 25b5366d8..dd02501b0 100644
--- a/src/scope.rs
+++ b/src/scope.rs
@@ -1,17 +1,18 @@
 use std::cell::RefCell;
 use std::fmt;
 use std::future::Future;
-use std::pin::Pin;
 use std::rc::Rc;
-use std::task::{Context, Poll};
+use std::task::Poll;
 
-use actix_http::{Extensions, Response};
-use actix_router::{ResourceDef, ResourceInfo, Router};
+use actix_http::Extensions;
+use actix_router::{ResourceDef, Router};
 use actix_service::boxed::{self, BoxService, BoxServiceFactory};
 use actix_service::{
-    apply, apply_fn_factory, IntoServiceFactory, Service, ServiceFactory, Transform,
+    apply, apply_fn_factory, IntoServiceFactory, Service, ServiceFactory, ServiceFactoryExt,
+    Transform,
 };
-use futures_util::future::{ok, Either, LocalBoxFuture, Ready};
+use futures_core::future::LocalBoxFuture;
+use futures_util::future::join_all;
 
 use crate::config::ServiceConfig;
 use crate::data::Data;
@@ -28,7 +29,6 @@ use crate::service::{
 type Guards = Vec<Box<dyn Guard>>;
 type HttpService = BoxService<ServiceRequest, ServiceResponse, Error>;
 type HttpNewService = BoxServiceFactory<(), ServiceRequest, ServiceResponse, Error, ()>;
-type BoxedResponse = LocalBoxFuture<'static, Result<ServiceResponse, Error>>;
 
 /// Resources scope.
 ///
@@ -58,14 +58,13 @@ type BoxedResponse = LocalBoxFuture<'static, Result<ServiceResponse, Error>>;
 ///  * /{project_id}/path1 - responds to all http method
 ///  * /{project_id}/path2 - `GET` requests
 ///  * /{project_id}/path3 - `HEAD` requests
-///
 pub struct Scope<T = ScopeEndpoint> {
     endpoint: T,
     rdef: String,
-    data: Option<Extensions>,
+    app_data: Option<Extensions>,
     services: Vec<Box<dyn AppServiceFactory>>,
     guards: Vec<Box<dyn Guard>>,
-    default: Rc<RefCell<Option<Rc<HttpNewService>>>>,
+    default: Option<Rc<HttpNewService>>,
     external: Vec<ResourceDef>,
     factory_ref: Rc<RefCell<Option<ScopeFactory>>>,
 }
@@ -77,10 +76,10 @@ impl Scope {
         Scope {
             endpoint: ScopeEndpoint::new(fref.clone()),
             rdef: path.to_string(),
-            data: None,
+            app_data: None,
             guards: Vec::new(),
             services: Vec::new(),
-            default: Rc::new(RefCell::new(None)),
+            default: None,
             external: Vec::new(),
             factory_ref: fref,
         }
@@ -90,8 +89,8 @@ impl Scope {
 impl<T> Scope<T>
 where
     T: ServiceFactory<
+        ServiceRequest,
         Config = (),
-        Request = ServiceRequest,
         Response = ServiceResponse,
         Error = Error,
         InitError = (),
@@ -156,10 +155,10 @@ where
     ///
     /// Data of different types from parent contexts will still be accessible.
     pub fn app_data<U: 'static>(mut self, data: U) -> Self {
-        if self.data.is_none() {
-            self.data = Some(Extensions::new());
-        }
-        self.data.as_mut().unwrap().insert(data);
+        self.app_data
+            .get_or_insert_with(Extensions::new)
+            .insert(data);
+
         self
     }
 
@@ -201,23 +200,17 @@ where
         self.services.extend(cfg.services);
         self.external.extend(cfg.external);
 
-        if !cfg.data.is_empty() {
-            let mut data = self.data.unwrap_or_else(Extensions::new);
-
-            for value in cfg.data.iter() {
-                value.create(&mut data);
-            }
-
-            self.data = Some(data);
-        }
+        self.app_data
+            .get_or_insert_with(Extensions::new)
+            .extend(cfg.app_data);
         self
     }
 
-    /// Register http service.
+    /// Register HTTP service.
     ///
     /// This is similar to `App's` service registration.
     ///
-    /// Actix web provides several services implementations:
+    /// Actix Web provides several services implementations:
     ///
     /// * *Resource* is an entry in resource table which corresponds to requested URL.
     /// * *Scope* is a set of resources with common root path.
@@ -283,21 +276,19 @@ where
     /// If default resource is not registered, app's default resource is being used.
     pub fn default_service<F, U>(mut self, f: F) -> Self
     where
-        F: IntoServiceFactory<U>,
+        F: IntoServiceFactory<U, ServiceRequest>,
         U: ServiceFactory<
+                ServiceRequest,
                 Config = (),
-                Request = ServiceRequest,
                 Response = ServiceResponse,
                 Error = Error,
             > + 'static,
         U::InitError: fmt::Debug,
     {
         // create and configure default resource
-        self.default = Rc::new(RefCell::new(Some(Rc::new(boxed::factory(
-            f.into_factory().map_init_err(|e| {
-                log::error!("Can not construct default service: {:?}", e)
-            }),
-        )))));
+        self.default = Some(Rc::new(boxed::factory(f.into_factory().map_init_err(
+            |e| log::error!("Can not construct default service: {:?}", e),
+        ))));
 
         self
     }
@@ -316,8 +307,8 @@ where
         mw: M,
     ) -> Scope<
         impl ServiceFactory<
+            ServiceRequest,
             Config = (),
-            Request = ServiceRequest,
             Response = ServiceResponse,
             Error = Error,
             InitError = (),
@@ -326,7 +317,7 @@ where
     where
         M: Transform<
             T::Service,
-            Request = ServiceRequest,
+            ServiceRequest,
             Response = ServiceResponse,
             Error = Error,
             InitError = (),
@@ -335,7 +326,7 @@ where
         Scope {
             endpoint: apply(mw, self.endpoint),
             rdef: self.rdef,
-            data: self.data,
+            app_data: self.app_data,
             guards: self.guards,
             services: self.services,
             default: self.default,
@@ -381,21 +372,21 @@ where
         mw: F,
     ) -> Scope<
         impl ServiceFactory<
+            ServiceRequest,
             Config = (),
-            Request = ServiceRequest,
             Response = ServiceResponse,
             Error = Error,
             InitError = (),
         >,
     >
     where
-        F: FnMut(ServiceRequest, &mut T::Service) -> R + Clone,
+        F: Fn(ServiceRequest, &T::Service) -> R + Clone,
         R: Future<Output = Result<ServiceResponse, Error>>,
     {
         Scope {
             endpoint: apply_fn_factory(self.endpoint, mw),
             rdef: self.rdef,
-            data: self.data,
+            app_data: self.app_data,
             guards: self.guards,
             services: self.services,
             default: self.default,
@@ -408,8 +399,8 @@ where
 impl<T> HttpServiceFactory for Scope<T>
 where
     T: ServiceFactory<
+            ServiceRequest,
             Config = (),
-            Request = ServiceRequest,
             Response = ServiceResponse,
             Error = Error,
             InitError = (),
@@ -417,9 +408,7 @@ where
 {
     fn register(mut self, config: &mut AppService) {
         // update default resource if needed
-        if self.default.borrow().is_none() {
-            *self.default.borrow_mut() = Some(config.default_service());
-        }
+        let default = self.default.unwrap_or_else(|| config.default_service());
 
         // register nested services
         let mut cfg = config.clone_config();
@@ -434,25 +423,21 @@ where
             rmap.add(&mut rdef, None);
         }
 
-        // custom app data storage
-        if let Some(ref mut ext) = self.data {
-            config.set_service_data(ext);
-        }
-
         // complete scope pipeline creation
         *self.factory_ref.borrow_mut() = Some(ScopeFactory {
-            data: self.data.take().map(Rc::new),
-            default: self.default.clone(),
-            services: Rc::new(
-                cfg.into_services()
-                    .1
-                    .into_iter()
-                    .map(|(mut rdef, srv, guards, nested)| {
-                        rmap.add(&mut rdef, nested);
-                        (rdef, srv, RefCell::new(guards))
-                    })
-                    .collect(),
-            ),
+            app_data: self.app_data.take().map(Rc::new),
+            default,
+            services: cfg
+                .into_services()
+                .1
+                .into_iter()
+                .map(|(mut rdef, srv, guards, nested)| {
+                    rmap.add(&mut rdef, nested);
+                    (rdef, srv, RefCell::new(guards))
+                })
+                .collect::<Vec<_>>()
+                .into_boxed_slice()
+                .into(),
         });
 
         // get guards
@@ -473,144 +458,75 @@ where
 }
 
 pub struct ScopeFactory {
-    data: Option<Rc<Extensions>>,
-    services: Rc<Vec<(ResourceDef, HttpNewService, RefCell<Option<Guards>>)>>,
-    default: Rc<RefCell<Option<Rc<HttpNewService>>>>,
+    app_data: Option<Rc<Extensions>>,
+    services: Rc<[(ResourceDef, HttpNewService, RefCell<Option<Guards>>)]>,
+    default: Rc<HttpNewService>,
 }
 
-impl ServiceFactory for ScopeFactory {
-    type Config = ();
-    type Request = ServiceRequest;
+impl ServiceFactory<ServiceRequest> for ScopeFactory {
     type Response = ServiceResponse;
     type Error = Error;
-    type InitError = ();
+    type Config = ();
     type Service = ScopeService;
-    type Future = ScopeFactoryResponse;
+    type InitError = ();
+    type Future = LocalBoxFuture<'static, Result<Self::Service, Self::InitError>>;
 
     fn new_service(&self, _: ()) -> Self::Future {
-        let default_fut = if let Some(ref default) = *self.default.borrow() {
-            Some(default.new_service(()))
-        } else {
-            None
-        };
+        // construct default service factory future
+        let default_fut = self.default.new_service(());
 
-        ScopeFactoryResponse {
-            fut: self
-                .services
-                .iter()
-                .map(|(path, service, guards)| {
-                    CreateScopeServiceItem::Future(
-                        Some(path.clone()),
-                        guards.borrow_mut().take(),
-                        service.new_service(()),
-                    )
-                })
-                .collect(),
-            default: None,
-            data: self.data.clone(),
-            default_fut,
-        }
-    }
-}
-
-/// Create scope service
-#[doc(hidden)]
-#[pin_project::pin_project]
-pub struct ScopeFactoryResponse {
-    fut: Vec<CreateScopeServiceItem>,
-    data: Option<Rc<Extensions>>,
-    default: Option<HttpService>,
-    default_fut: Option<LocalBoxFuture<'static, Result<HttpService, ()>>>,
-}
-
-type HttpServiceFut = LocalBoxFuture<'static, Result<HttpService, ()>>;
-
-enum CreateScopeServiceItem {
-    Future(Option<ResourceDef>, Option<Guards>, HttpServiceFut),
-    Service(ResourceDef, Option<Guards>, HttpService),
-}
-
-impl Future for ScopeFactoryResponse {
-    type Output = Result<ScopeService, ()>;
-
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let mut done = true;
-
-        if let Some(ref mut fut) = self.default_fut {
-            match Pin::new(fut).poll(cx)? {
-                Poll::Ready(default) => self.default = Some(default),
-                Poll::Pending => done = false,
+        // construct all services factory future with it's resource def and guards.
+        let factory_fut = join_all(self.services.iter().map(|(path, factory, guards)| {
+            let path = path.clone();
+            let guards = guards.borrow_mut().take();
+            let factory_fut = factory.new_service(());
+            async move {
+                let service = factory_fut.await?;
+                Ok((path, guards, service))
             }
-        }
+        }));
 
-        // poll http services
-        for item in &mut self.fut {
-            let res = match item {
-                CreateScopeServiceItem::Future(
-                    ref mut path,
-                    ref mut guards,
-                    ref mut fut,
-                ) => match Pin::new(fut).poll(cx)? {
-                    Poll::Ready(service) => {
-                        Some((path.take().unwrap(), guards.take(), service))
-                    }
-                    Poll::Pending => {
-                        done = false;
-                        None
-                    }
-                },
-                CreateScopeServiceItem::Service(_, _, _) => continue,
-            };
+        let app_data = self.app_data.clone();
 
-            if let Some((path, guards, service)) = res {
-                *item = CreateScopeServiceItem::Service(path, guards, service);
-            }
-        }
+        Box::pin(async move {
+            let default = default_fut.await?;
 
-        if done {
-            let router = self
-                .fut
+            // build router from the factory future result.
+            let router = factory_fut
+                .await
+                .into_iter()
+                .collect::<Result<Vec<_>, _>>()?
                 .drain(..)
-                .fold(Router::build(), |mut router, item| {
-                    match item {
-                        CreateScopeServiceItem::Service(path, guards, service) => {
-                            router.rdef(path, service).2 = guards;
-                        }
-                        CreateScopeServiceItem::Future(_, _, _) => unreachable!(),
-                    }
+                .fold(Router::build(), |mut router, (path, guards, service)| {
+                    router.rdef(path, service).2 = guards;
                     router
-                });
-            Poll::Ready(Ok(ScopeService {
-                data: self.data.clone(),
-                router: router.finish(),
-                default: self.default.take(),
-                _ready: None,
-            }))
-        } else {
-            Poll::Pending
-        }
+                })
+                .finish();
+
+            Ok(ScopeService {
+                app_data,
+                router,
+                default,
+            })
+        })
     }
 }
 
 pub struct ScopeService {
-    data: Option<Rc<Extensions>>,
+    app_data: Option<Rc<Extensions>>,
     router: Router<HttpService, Vec<Box<dyn Guard>>>,
-    default: Option<HttpService>,
-    _ready: Option<(ServiceRequest, ResourceInfo)>,
+    default: HttpService,
 }
 
-impl Service for ScopeService {
-    type Request = ServiceRequest;
+impl Service<ServiceRequest> for ScopeService {
     type Response = ServiceResponse;
     type Error = Error;
-    type Future = Either<BoxedResponse, Ready<Result<Self::Response, Self::Error>>>;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
+    actix_service::always_ready!();
 
-    fn call(&mut self, mut req: ServiceRequest) -> Self::Future {
-        let res = self.router.recognize_mut_checked(&mut req, |req, guards| {
+    fn call(&self, mut req: ServiceRequest) -> Self::Future {
+        let res = self.router.recognize_checked(&mut req, |req, guards| {
             if let Some(ref guards) = guards {
                 for f in guards {
                     if !f.check(req.head()) {
@@ -621,19 +537,14 @@ impl Service for ScopeService {
             true
         });
 
+        if let Some(ref app_data) = self.app_data {
+            req.add_data_container(app_data.clone());
+        }
+
         if let Some((srv, _info)) = res {
-            if let Some(ref data) = self.data {
-                req.add_data_container(data.clone());
-            }
-            Either::Left(srv.call(req))
-        } else if let Some(ref mut default) = self.default {
-            if let Some(ref data) = self.data {
-                req.add_data_container(data.clone());
-            }
-            Either::Left(default.call(req))
+            srv.call(req)
         } else {
-            let req = req.into_parts().0;
-            Either::Right(ok(ServiceResponse::new(req, Response::NotFound().finish())))
+            self.default.call(req)
         }
     }
 }
@@ -649,14 +560,13 @@ impl ScopeEndpoint {
     }
 }
 
-impl ServiceFactory for ScopeEndpoint {
-    type Config = ();
-    type Request = ServiceRequest;
+impl ServiceFactory<ServiceRequest> for ScopeEndpoint {
     type Response = ServiceResponse;
     type Error = Error;
-    type InitError = ();
+    type Config = ();
     type Service = ScopeService;
-    type Future = ScopeFactoryResponse;
+    type InitError = ();
+    type Future = LocalBoxFuture<'static, Result<Self::Service, Self::InitError>>;
 
     fn new_service(&self, _: ()) -> Self::Future {
         self.factory.borrow_mut().as_mut().unwrap().new_service(())
@@ -678,10 +588,11 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_scope() {
-        let mut srv = init_service(App::new().service(
-            web::scope("/app").service(web::resource("/path1").to(HttpResponse::Ok)),
-        ))
-        .await;
+        let srv =
+            init_service(App::new().service(
+                web::scope("/app").service(web::resource("/path1").to(HttpResponse::Ok)),
+            ))
+            .await;
 
         let req = TestRequest::with_uri("/app/path1").to_request();
         let resp = srv.call(req).await.unwrap();
@@ -690,7 +601,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_scope_root() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("/app")
                     .service(web::resource("").to(HttpResponse::Ok))
@@ -710,9 +621,10 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_scope_root2() {
-        let mut srv = init_service(App::new().service(
-            web::scope("/app/").service(web::resource("").to(HttpResponse::Ok)),
-        ))
+        let srv = init_service(
+            App::new()
+                .service(web::scope("/app/").service(web::resource("").to(HttpResponse::Ok))),
+        )
         .await;
 
         let req = TestRequest::with_uri("/app").to_request();
@@ -726,9 +638,10 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_scope_root3() {
-        let mut srv = init_service(App::new().service(
-            web::scope("/app/").service(web::resource("/").to(HttpResponse::Ok)),
-        ))
+        let srv = init_service(
+            App::new()
+                .service(web::scope("/app/").service(web::resource("/").to(HttpResponse::Ok))),
+        )
         .await;
 
         let req = TestRequest::with_uri("/app").to_request();
@@ -742,7 +655,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_scope_route() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("app")
                     .route("/path1", web::get().to(HttpResponse::Ok))
@@ -770,7 +683,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_scope_route_without_leading_slash() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("app").service(
                     web::resource("path1")
@@ -800,7 +713,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_scope_guard() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("/app")
                     .guard(guard::Get())
@@ -824,14 +737,12 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_scope_variable_segment() {
-        let mut srv =
-            init_service(App::new().service(web::scope("/ab-{project}").service(
-                web::resource("/path1").to(|r: HttpRequest| {
-                    HttpResponse::Ok()
-                        .body(format!("project: {}", &r.match_info()["project"]))
-                }),
-            )))
-            .await;
+        let srv = init_service(App::new().service(web::scope("/ab-{project}").service(
+            web::resource("/path1").to(|r: HttpRequest| {
+                HttpResponse::Ok().body(format!("project: {}", &r.match_info()["project"]))
+            }),
+        )))
+        .await;
 
         let req = TestRequest::with_uri("/ab-project1/path1").to_request();
         let resp = srv.call(req).await.unwrap();
@@ -852,7 +763,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_nested_scope() {
-        let mut srv = init_service(App::new().service(web::scope("/app").service(
+        let srv = init_service(App::new().service(web::scope("/app").service(
             web::scope("/t1").service(web::resource("/path1").to(HttpResponse::Created)),
         )))
         .await;
@@ -864,7 +775,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_nested_scope_no_slash() {
-        let mut srv = init_service(App::new().service(web::scope("/app").service(
+        let srv = init_service(App::new().service(web::scope("/app").service(
             web::scope("t1").service(web::resource("/path1").to(HttpResponse::Created)),
         )))
         .await;
@@ -876,7 +787,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_nested_scope_root() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("/app").service(
                     web::scope("/t1")
@@ -898,7 +809,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_nested_scope_filter() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("/app").service(
                     web::scope("/t1")
@@ -924,7 +835,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_nested_scope_with_variable_segment() {
-        let mut srv = init_service(App::new().service(web::scope("/app").service(
+        let srv = init_service(App::new().service(web::scope("/app").service(
             web::scope("/{project_id}").service(web::resource("/path1").to(
                 |r: HttpRequest| {
                     HttpResponse::Created()
@@ -949,7 +860,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_nested2_scope_with_variable_segment() {
-        let mut srv = init_service(App::new().service(web::scope("/app").service(
+        let srv = init_service(App::new().service(web::scope("/app").service(
             web::scope("/{project}").service(web::scope("/{id}").service(
                 web::resource("/path1").to(|r: HttpRequest| {
                     HttpResponse::Created().body(format!(
@@ -981,7 +892,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_default_resource() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("/app")
                     .service(web::resource("/path1").to(HttpResponse::Ok))
@@ -1003,7 +914,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_default_resource_propagation() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .service(
                     web::scope("/app1")
@@ -1031,24 +942,20 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_middleware() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("app")
                     .wrap(
-                        DefaultHeaders::new().header(
-                            header::CONTENT_TYPE,
-                            HeaderValue::from_static("0001"),
-                        ),
+                        DefaultHeaders::new()
+                            .header(header::CONTENT_TYPE, HeaderValue::from_static("0001")),
                     )
-                    .service(
-                        web::resource("/test").route(web::get().to(HttpResponse::Ok)),
-                    ),
+                    .service(web::resource("/test").route(web::get().to(HttpResponse::Ok))),
             ),
         )
         .await;
 
         let req = TestRequest::with_uri("/app/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
@@ -1058,17 +965,15 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_middleware_fn() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(
                 web::scope("app")
                     .wrap_fn(|req, srv| {
                         let fut = srv.call(req);
                         async move {
                             let mut res = fut.await?;
-                            res.headers_mut().insert(
-                                header::CONTENT_TYPE,
-                                HeaderValue::from_static("0001"),
-                            );
+                            res.headers_mut()
+                                .insert(header::CONTENT_TYPE, HeaderValue::from_static("0001"));
                             Ok(res)
                         }
                     })
@@ -1078,7 +983,7 @@ mod tests {
         .await;
 
         let req = TestRequest::with_uri("/app/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
@@ -1088,7 +993,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_override_data() {
-        let mut srv = init_service(App::new().data(1usize).service(
+        let srv = init_service(App::new().data(1usize).service(
             web::scope("app").data(10usize).route(
                 "/t",
                 web::get().to(|data: web::Data<usize>| {
@@ -1100,13 +1005,13 @@ mod tests {
         .await;
 
         let req = TestRequest::with_uri("/app/t").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 
     #[actix_rt::test]
     async fn test_override_data_default_service() {
-        let mut srv = init_service(App::new().data(1usize).service(
+        let srv = init_service(App::new().data(1usize).service(
             web::scope("app").data(10usize).default_service(web::to(
                 |data: web::Data<usize>| {
                     assert_eq!(**data, 10);
@@ -1117,13 +1022,13 @@ mod tests {
         .await;
 
         let req = TestRequest::with_uri("/app/t").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 
     #[actix_rt::test]
     async fn test_override_app_data() {
-        let mut srv = init_service(App::new().app_data(web::Data::new(1usize)).service(
+        let srv = init_service(App::new().app_data(web::Data::new(1usize)).service(
             web::scope("app").app_data(web::Data::new(10usize)).route(
                 "/t",
                 web::get().to(|data: web::Data<usize>| {
@@ -1135,17 +1040,16 @@ mod tests {
         .await;
 
         let req = TestRequest::with_uri("/app/t").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 
     #[actix_rt::test]
     async fn test_scope_config() {
-        let mut srv =
-            init_service(App::new().service(web::scope("/app").configure(|s| {
-                s.route("/path1", web::get().to(HttpResponse::Ok));
-            })))
-            .await;
+        let srv = init_service(App::new().service(web::scope("/app").configure(|s| {
+            s.route("/path1", web::get().to(HttpResponse::Ok));
+        })))
+        .await;
 
         let req = TestRequest::with_uri("/app/path1").to_request();
         let resp = srv.call(req).await.unwrap();
@@ -1154,13 +1058,12 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_scope_config_2() {
-        let mut srv =
-            init_service(App::new().service(web::scope("/app").configure(|s| {
-                s.service(web::scope("/v1").configure(|s| {
-                    s.route("/", web::get().to(HttpResponse::Ok));
-                }));
-            })))
-            .await;
+        let srv = init_service(App::new().service(web::scope("/app").configure(|s| {
+            s.service(web::scope("/v1").configure(|s| {
+                s.route("/", web::get().to(HttpResponse::Ok));
+            }));
+        })))
+        .await;
 
         let req = TestRequest::with_uri("/app/v1/").to_request();
         let resp = srv.call(req).await.unwrap();
@@ -1169,24 +1072,19 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_url_for_external() {
-        let mut srv =
-            init_service(App::new().service(web::scope("/app").configure(|s| {
-                s.service(web::scope("/v1").configure(|s| {
-                    s.external_resource(
-                        "youtube",
-                        "https://youtube.com/watch/{video_id}",
-                    );
-                    s.route(
-                        "/",
-                        web::get().to(|req: HttpRequest| {
-                            HttpResponse::Ok().body(
-                                req.url_for("youtube", &["xxxxxx"]).unwrap().to_string(),
-                            )
-                        }),
-                    );
-                }));
-            })))
-            .await;
+        let srv = init_service(App::new().service(web::scope("/app").configure(|s| {
+            s.service(web::scope("/v1").configure(|s| {
+                s.external_resource("youtube", "https://youtube.com/watch/{video_id}");
+                s.route(
+                    "/",
+                    web::get().to(|req: HttpRequest| {
+                        HttpResponse::Ok()
+                            .body(req.url_for("youtube", &["xxxxxx"]).unwrap().to_string())
+                    }),
+                );
+            }));
+        })))
+        .await;
 
         let req = TestRequest::with_uri("/app/v1/").to_request();
         let resp = srv.call(req).await.unwrap();
@@ -1197,7 +1095,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_url_for_nested() {
-        let mut srv = init_service(App::new().service(web::scope("/a").service(
+        let srv = init_service(App::new().service(web::scope("/a").service(
             web::scope("/b").service(web::resource("/c/{stuff}").name("c").route(
                 web::get().to(|req: HttpRequest| {
                     HttpResponse::Ok()
@@ -1208,7 +1106,7 @@ mod tests {
         .await;
 
         let req = TestRequest::with_uri("/a/b/c/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
         let body = read_body(resp).await;
         assert_eq!(
diff --git a/src/server.rs b/src/server.rs
index 2b86f7416..d69d6570d 100644
--- a/src/server.rs
+++ b/src/server.rs
@@ -1,8 +1,14 @@
-use std::marker::PhantomData;
-use std::sync::{Arc, Mutex};
-use std::{fmt, io, net};
+use std::{
+    any::Any,
+    cmp, fmt, io,
+    marker::PhantomData,
+    net,
+    sync::{Arc, Mutex},
+};
 
-use actix_http::{body::MessageBody, Error, HttpService, KeepAlive, Request, Response};
+use actix_http::{
+    body::MessageBody, Error, Extensions, HttpService, KeepAlive, Request, Response,
+};
 use actix_server::{Server, ServerBuilder};
 use actix_service::{map_config, IntoServiceFactory, Service, ServiceFactory};
 
@@ -14,9 +20,9 @@ use actix_service::pipeline_factory;
 use futures_util::future::ok;
 
 #[cfg(feature = "openssl")]
-use actix_tls::openssl::{AlpnError, SslAcceptor, SslAcceptorBuilder};
+use actix_tls::accept::openssl::{AlpnError, SslAcceptor, SslAcceptorBuilder};
 #[cfg(feature = "rustls")]
-use actix_tls::rustls::ServerConfig as RustlsServerConfig;
+use actix_tls::accept::rustls::ServerConfig as RustlsServerConfig;
 
 use crate::config::AppConfig;
 
@@ -34,7 +40,7 @@ struct Config {
 
 /// An HTTP Server.
 ///
-/// Create new http server with application factory.
+/// Create new HTTP server with application factory.
 ///
 /// ```rust,no_run
 /// use actix_web::{web, App, HttpResponse, HttpServer};
@@ -52,8 +58,8 @@ struct Config {
 pub struct HttpServer<F, I, S, B>
 where
     F: Fn() -> I + Send + Clone + 'static,
-    I: IntoServiceFactory<S>,
-    S: ServiceFactory<Config = AppConfig, Request = Request>,
+    I: IntoServiceFactory<S, Request>,
+    S: ServiceFactory<Request, Config = AppConfig>,
     S::Error: Into<Error>,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>>,
@@ -61,24 +67,26 @@ where
 {
     pub(super) factory: F,
     config: Arc<Mutex<Config>>,
-    backlog: i32,
+    backlog: u32,
     sockets: Vec<Socket>,
     builder: ServerBuilder,
-    _t: PhantomData<(S, B)>,
+    on_connect_fn: Option<Arc<dyn Fn(&dyn Any, &mut Extensions) + Send + Sync>>,
+    _phantom: PhantomData<(S, B)>,
 }
 
 impl<F, I, S, B> HttpServer<F, I, S, B>
 where
     F: Fn() -> I + Send + Clone + 'static,
-    I: IntoServiceFactory<S>,
-    S: ServiceFactory<Config = AppConfig, Request = Request>,
+    I: IntoServiceFactory<S, Request>,
+    S: ServiceFactory<Request, Config = AppConfig> + 'static,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
+    S::Service: 'static,
     B: MessageBody + 'static,
 {
-    /// Create new http server with application factory
+    /// Create new HTTP server with application factory
     pub fn new(factory: F) -> Self {
         HttpServer {
             factory,
@@ -91,14 +99,39 @@ where
             backlog: 1024,
             sockets: Vec::new(),
             builder: ServerBuilder::default(),
-            _t: PhantomData,
+            on_connect_fn: None,
+            _phantom: PhantomData,
+        }
+    }
+
+    /// Sets function that will be called once before each connection is handled.
+    /// It will receive a `&std::any::Any`, which contains underlying connection type and an
+    /// [Extensions] container so that request-local data can be passed to middleware and handlers.
+    ///
+    /// For example:
+    /// - `actix_tls::openssl::SslStream<actix_web::rt::net::TcpStream>` when using openssl.
+    /// - `actix_tls::rustls::TlsStream<actix_web::rt::net::TcpStream>` when using rustls.
+    /// - `actix_web::rt::net::TcpStream` when no encryption is used.
+    ///
+    /// See `on_connect` example for additional details.
+    pub fn on_connect<CB>(self, f: CB) -> HttpServer<F, I, S, B>
+    where
+        CB: Fn(&dyn Any, &mut Extensions) + Send + Sync + 'static,
+    {
+        HttpServer {
+            factory: self.factory,
+            config: self.config,
+            backlog: self.backlog,
+            sockets: self.sockets,
+            builder: self.builder,
+            on_connect_fn: Some(Arc::new(f)),
+            _phantom: PhantomData,
         }
     }
 
     /// Set number of workers to start.
     ///
-    /// By default http server uses number of available logical cpu as threads
-    /// count.
+    /// By default, server uses number of available logical CPU as thread count.
     pub fn workers(mut self, num: usize) -> Self {
         self.builder = self.builder.workers(num);
         self
@@ -114,7 +147,7 @@ where
     /// Generally set in the 64-2048 range. Default value is 2048.
     ///
     /// This method should be called before `bind()` method call.
-    pub fn backlog(mut self, backlog: i32) -> Self {
+    pub fn backlog(mut self, backlog: u32) -> Self {
         self.backlog = backlog;
         self.builder = self.builder.backlog(backlog);
         self
@@ -137,8 +170,10 @@ where
     /// limit the global TLS CPU usage.
     ///
     /// By default max connections is set to a 256.
+    #[allow(unused_variables)]
     pub fn max_connection_rate(self, num: usize) -> Self {
-        actix_tls::max_concurrent_tls_connect(num);
+        #[cfg(any(feature = "rustls", feature = "openssl"))]
+        actix_tls::accept::max_concurrent_tls_connect(num);
         self
     }
 
@@ -180,7 +215,7 @@ where
     /// Set server host name.
     ///
     /// Host name is used by application router as a hostname for url generation.
-    /// Check [ConnectionInfo](./dev/struct.ConnectionInfo.html#method.host)
+    /// Check [ConnectionInfo](super::dev::ConnectionInfo::host())
     /// documentation for more information.
     ///
     /// By default host name is set to a "localhost" value.
@@ -221,7 +256,7 @@ where
     /// Get addresses of bound sockets and the scheme for it.
     ///
     /// This is useful when the server is bound from different sources
-    /// with some sockets listening on http and some listening on https
+    /// with some sockets listening on HTTP and some listening on HTTPS
     /// and the user should be presented with an enumeration of which
     /// socket requires which protocol.
     pub fn addrs_with_scheme(&self) -> Vec<(net::SocketAddr, &str)> {
@@ -240,26 +275,30 @@ where
             addr,
             scheme: "http",
         });
+        let on_connect_fn = self.on_connect_fn.clone();
 
-        self.builder = self.builder.listen(
-            format!("actix-web-service-{}", addr),
-            lst,
-            move || {
-                let c = cfg.lock().unwrap();
-                let cfg = AppConfig::new(
-                    false,
-                    addr,
-                    c.host.clone().unwrap_or_else(|| format!("{}", addr)),
-                );
+        self.builder =
+            self.builder
+                .listen(format!("actix-web-service-{}", addr), lst, move || {
+                    let c = cfg.lock().unwrap();
+                    let host = c.host.clone().unwrap_or_else(|| format!("{}", addr));
 
-                HttpService::build()
-                    .keep_alive(c.keep_alive)
-                    .client_timeout(c.client_timeout)
-                    .local_addr(addr)
-                    .finish(map_config(factory(), move |_| cfg.clone()))
+                    let svc = HttpService::build()
+                        .keep_alive(c.keep_alive)
+                        .client_timeout(c.client_timeout)
+                        .local_addr(addr);
+
+                    let svc = if let Some(handler) = on_connect_fn.clone() {
+                        svc.on_connect_ext(move |io: &_, ext: _| (handler)(io as &dyn Any, ext))
+                    } else {
+                        svc
+                    };
+
+                    svc.finish(map_config(factory(), move |_| {
+                        AppConfig::new(false, addr, host.clone())
+                    }))
                     .tcp()
-            },
-        )?;
+                })?;
         Ok(self)
     }
 
@@ -289,24 +328,32 @@ where
             scheme: "https",
         });
 
-        self.builder = self.builder.listen(
-            format!("actix-web-service-{}", addr),
-            lst,
-            move || {
-                let c = cfg.lock().unwrap();
-                let cfg = AppConfig::new(
-                    true,
-                    addr,
-                    c.host.clone().unwrap_or_else(|| format!("{}", addr)),
-                );
-                HttpService::build()
-                    .keep_alive(c.keep_alive)
-                    .client_timeout(c.client_timeout)
-                    .client_disconnect(c.client_shutdown)
-                    .finish(map_config(factory(), move |_| cfg.clone()))
+        let on_connect_fn = self.on_connect_fn.clone();
+
+        self.builder =
+            self.builder
+                .listen(format!("actix-web-service-{}", addr), lst, move || {
+                    let c = cfg.lock().unwrap();
+                    let host = c.host.clone().unwrap_or_else(|| format!("{}", addr));
+
+                    let svc = HttpService::build()
+                        .keep_alive(c.keep_alive)
+                        .client_timeout(c.client_timeout)
+                        .client_disconnect(c.client_shutdown);
+
+                    let svc = if let Some(handler) = on_connect_fn.clone() {
+                        svc.on_connect_ext(move |io: &_, ext: _| {
+                            (&*handler)(io as &dyn Any, ext)
+                        })
+                    } else {
+                        svc
+                    };
+
+                    svc.finish(map_config(factory(), move |_| {
+                        AppConfig::new(true, addr, host.clone())
+                    }))
                     .openssl(acceptor.clone())
-            },
-        )?;
+                })?;
         Ok(self)
     }
 
@@ -336,24 +383,30 @@ where
             scheme: "https",
         });
 
-        self.builder = self.builder.listen(
-            format!("actix-web-service-{}", addr),
-            lst,
-            move || {
-                let c = cfg.lock().unwrap();
-                let cfg = AppConfig::new(
-                    true,
-                    addr,
-                    c.host.clone().unwrap_or_else(|| format!("{}", addr)),
-                );
-                HttpService::build()
-                    .keep_alive(c.keep_alive)
-                    .client_timeout(c.client_timeout)
-                    .client_disconnect(c.client_shutdown)
-                    .finish(map_config(factory(), move |_| cfg.clone()))
+        let on_connect_fn = self.on_connect_fn.clone();
+
+        self.builder =
+            self.builder
+                .listen(format!("actix-web-service-{}", addr), lst, move || {
+                    let c = cfg.lock().unwrap();
+                    let host = c.host.clone().unwrap_or_else(|| format!("{}", addr));
+
+                    let svc = HttpService::build()
+                        .keep_alive(c.keep_alive)
+                        .client_timeout(c.client_timeout)
+                        .client_disconnect(c.client_shutdown);
+
+                    let svc = if let Some(handler) = on_connect_fn.clone() {
+                        svc.on_connect_ext(move |io: &_, ext: _| (handler)(io as &dyn Any, ext))
+                    } else {
+                        svc
+                    };
+
+                    svc.finish(map_config(factory(), move |_| {
+                        AppConfig::new(true, addr, host.clone())
+                    }))
                     .rustls(config.clone())
-            },
-        )?;
+                })?;
         Ok(self)
     }
 
@@ -370,10 +423,7 @@ where
         Ok(self)
     }
 
-    fn bind2<A: net::ToSocketAddrs>(
-        &self,
-        addr: A,
-    ) -> io::Result<Vec<net::TcpListener>> {
+    fn bind2<A: net::ToSocketAddrs>(&self, addr: A) -> io::Result<Vec<net::TcpListener>> {
         let mut err = None;
         let mut success = false;
         let mut sockets = Vec::new();
@@ -406,11 +456,7 @@ where
     /// Start listening for incoming tls connections.
     ///
     /// This method sets alpn protocols to "h2" and "http/1.1"
-    pub fn bind_openssl<A>(
-        mut self,
-        addr: A,
-        builder: SslAcceptorBuilder,
-    ) -> io::Result<Self>
+    pub fn bind_openssl<A>(mut self, addr: A, builder: SslAcceptorBuilder) -> io::Result<Self>
     where
         A: net::ToSocketAddrs,
     {
@@ -441,25 +487,21 @@ where
     }
 
     #[cfg(unix)]
-    /// Start listening for unix domain connections on existing listener.
-    pub fn listen_uds(
-        mut self,
-        lst: std::os::unix::net::UnixListener,
-    ) -> io::Result<Self> {
+    /// Start listening for unix domain (UDS) connections on existing listener.
+    pub fn listen_uds(mut self, lst: std::os::unix::net::UnixListener) -> io::Result<Self> {
         use actix_rt::net::UnixStream;
 
         let cfg = self.config.clone();
         let factory = self.factory.clone();
-        let socket_addr = net::SocketAddr::new(
-            net::IpAddr::V4(net::Ipv4Addr::new(127, 0, 0, 1)),
-            8080,
-        );
+        let socket_addr =
+            net::SocketAddr::new(net::IpAddr::V4(net::Ipv4Addr::new(127, 0, 0, 1)), 8080);
         self.sockets.push(Socket {
             scheme: "http",
             addr: socket_addr,
         });
 
         let addr = format!("actix-web-service-{:?}", lst.local_addr()?);
+        let on_connect_fn = self.on_connect_fn.clone();
 
         self.builder = self.builder.listen_uds(addr, lst, move || {
             let c = cfg.lock().unwrap();
@@ -468,12 +510,20 @@ where
                 socket_addr,
                 c.host.clone().unwrap_or_else(|| format!("{}", socket_addr)),
             );
-            pipeline_factory(|io: UnixStream| ok((io, Protocol::Http1, None))).and_then(
-                HttpService::build()
+
+            pipeline_factory(|io: UnixStream| ok((io, Protocol::Http1, None))).and_then({
+                let svc = HttpService::build()
                     .keep_alive(c.keep_alive)
-                    .client_timeout(c.client_timeout)
-                    .finish(map_config(factory(), move |_| config.clone())),
-            )
+                    .client_timeout(c.client_timeout);
+
+                let svc = if let Some(handler) = on_connect_fn.clone() {
+                    svc.on_connect_ext(move |io: &_, ext: _| (&*handler)(io as &dyn Any, ext))
+                } else {
+                    svc
+                };
+
+                svc.finish(map_config(factory(), move |_| config.clone()))
+            })
         })?;
         Ok(self)
     }
@@ -488,10 +538,8 @@ where
 
         let cfg = self.config.clone();
         let factory = self.factory.clone();
-        let socket_addr = net::SocketAddr::new(
-            net::IpAddr::V4(net::Ipv4Addr::new(127, 0, 0, 1)),
-            8080,
-        );
+        let socket_addr =
+            net::SocketAddr::new(net::IpAddr::V4(net::Ipv4Addr::new(127, 0, 0, 1)), 8080);
         self.sockets.push(Socket {
             scheme: "http",
             addr: socket_addr,
@@ -507,13 +555,12 @@ where
                     socket_addr,
                     c.host.clone().unwrap_or_else(|| format!("{}", socket_addr)),
                 );
-                pipeline_factory(|io: UnixStream| ok((io, Protocol::Http1, None)))
-                    .and_then(
-                        HttpService::build()
-                            .keep_alive(c.keep_alive)
-                            .client_timeout(c.client_timeout)
-                            .finish(map_config(factory(), move |_| config.clone())),
-                    )
+                pipeline_factory(|io: UnixStream| ok((io, Protocol::Http1, None))).and_then(
+                    HttpService::build()
+                        .keep_alive(c.keep_alive)
+                        .client_timeout(c.client_timeout)
+                        .finish(map_config(factory(), move |_| config.clone())),
+                )
             },
         )?;
         Ok(self)
@@ -523,8 +570,8 @@ where
 impl<F, I, S, B> HttpServer<F, I, S, B>
 where
     F: Fn() -> I + Send + Clone + 'static,
-    I: IntoServiceFactory<S>,
-    S: ServiceFactory<Config = AppConfig, Request = Request>,
+    I: IntoServiceFactory<S, Request>,
+    S: ServiceFactory<Request, Config = AppConfig>,
     S::Error: Into<Error>,
     S::InitError: fmt::Debug,
     S::Response: Into<Response<B>>,
@@ -533,7 +580,7 @@ where
 {
     /// Start listening for incoming connections.
     ///
-    /// This method starts number of http workers in separate threads.
+    /// This method starts number of HTTP workers in separate threads.
     /// For each address this method starts separate thread which does
     /// `accept()` in a loop.
     ///
@@ -553,14 +600,11 @@ where
     /// }
     /// ```
     pub fn run(self) -> Server {
-        self.builder.start()
+        self.builder.run()
     }
 }
 
-fn create_tcp_listener(
-    addr: net::SocketAddr,
-    backlog: i32,
-) -> io::Result<net::TcpListener> {
+fn create_tcp_listener(addr: net::SocketAddr, backlog: u32) -> io::Result<net::TcpListener> {
     use socket2::{Domain, Protocol, Socket, Type};
     let domain = match addr {
         net::SocketAddr::V4(_) => Domain::ipv4(),
@@ -569,6 +613,8 @@ fn create_tcp_listener(
     let socket = Socket::new(domain, Type::stream(), Some(Protocol::tcp()))?;
     socket.set_reuse_address(true)?;
     socket.bind(&addr.into())?;
+    // clamp backlog to max u32 that fits in i32 range
+    let backlog = cmp::min(backlog, i32::MAX as u32) as i32;
     socket.listen(backlog)?;
     Ok(socket.into_tcp_listener())
 }
diff --git a/src/service.rs b/src/service.rs
index a861ba38c..fcbe61a02 100644
--- a/src/service.rs
+++ b/src/service.rs
@@ -5,8 +5,7 @@ use std::{fmt, net};
 use actix_http::body::{Body, MessageBody, ResponseBody};
 use actix_http::http::{HeaderMap, Method, StatusCode, Uri, Version};
 use actix_http::{
-    Error, Extensions, HttpMessage, Payload, PayloadStream, RequestHead, Response,
-    ResponseHead,
+    Error, Extensions, HttpMessage, Payload, PayloadStream, RequestHead, Response, ResponseHead,
 };
 use actix_router::{IntoPattern, Path, Resource, ResourceDef, Url};
 use actix_service::{IntoServiceFactory, ServiceFactory};
@@ -22,6 +21,13 @@ pub trait HttpServiceFactory {
     fn register(self, config: &mut AppService);
 }
 
+impl<T: HttpServiceFactory> HttpServiceFactory for Vec<T> {
+    fn register(self, config: &mut AppService) {
+        self.into_iter()
+            .for_each(|factory| factory.register(config));
+    }
+}
+
 pub(crate) trait AppServiceFactory {
     fn register(&mut self, config: &mut AppService);
 }
@@ -52,71 +58,61 @@ where
 /// An service http request
 ///
 /// ServiceRequest allows mutable access to request's internal structures
-pub struct ServiceRequest(HttpRequest);
+pub struct ServiceRequest {
+    req: HttpRequest,
+    payload: Payload,
+}
 
 impl ServiceRequest {
     /// Construct service request
-    pub(crate) fn new(req: HttpRequest) -> Self {
-        ServiceRequest(req)
+    pub(crate) fn new(req: HttpRequest, payload: Payload) -> Self {
+        Self { req, payload }
     }
 
     /// Deconstruct request into parts
-    pub fn into_parts(mut self) -> (HttpRequest, Payload) {
-        let pl = Rc::get_mut(&mut (self.0).0).unwrap().payload.take();
-        (self.0, pl)
+    #[inline]
+    pub fn into_parts(self) -> (HttpRequest, Payload) {
+        (self.req, self.payload)
     }
 
     /// Construct request from parts.
-    ///
-    /// `ServiceRequest` can be re-constructed only if `req` hasn't been cloned.
-    pub fn from_parts(
-        mut req: HttpRequest,
-        pl: Payload,
-    ) -> Result<Self, (HttpRequest, Payload)> {
-        if Rc::strong_count(&req.0) == 1 && Rc::weak_count(&req.0) == 0 {
-            Rc::get_mut(&mut req.0).unwrap().payload = pl;
-            Ok(ServiceRequest(req))
-        } else {
-            Err((req, pl))
-        }
+    pub fn from_parts(req: HttpRequest, payload: Payload) -> Self {
+        Self { req, payload }
     }
 
     /// Construct request from request.
     ///
-    /// `HttpRequest` implements `Clone` trait via `Rc` type. `ServiceRequest`
-    /// can be re-constructed only if rc's strong pointers count eq 1 and
-    /// weak pointers count is 0.
-    pub fn from_request(req: HttpRequest) -> Result<Self, HttpRequest> {
-        if Rc::strong_count(&req.0) == 1 && Rc::weak_count(&req.0) == 0 {
-            Ok(ServiceRequest(req))
-        } else {
-            Err(req)
+    /// The returned `ServiceRequest` would have no payload.
+    pub fn from_request(req: HttpRequest) -> Self {
+        ServiceRequest {
+            req,
+            payload: Payload::None,
         }
     }
 
     /// Create service response
     #[inline]
     pub fn into_response<B, R: Into<Response<B>>>(self, res: R) -> ServiceResponse<B> {
-        ServiceResponse::new(self.0, res.into())
+        ServiceResponse::new(self.req, res.into())
     }
 
     /// Create service response for error
     #[inline]
     pub fn error_response<B, E: Into<Error>>(self, err: E) -> ServiceResponse<B> {
         let res: Response = err.into().into();
-        ServiceResponse::new(self.0, res.into_body())
+        ServiceResponse::new(self.req, res.into_body())
     }
 
     /// This method returns reference to the request head
     #[inline]
     pub fn head(&self) -> &RequestHead {
-        &self.0.head()
+        &self.req.head()
     }
 
     /// This method returns reference to the request head
     #[inline]
     pub fn head_mut(&mut self) -> &mut RequestHead {
-        self.0.head_mut()
+        self.req.head_mut()
     }
 
     /// Request's uri.
@@ -167,12 +163,14 @@ impl ServiceRequest {
         }
     }
 
-    /// Peer socket address
+    /// Peer socket address.
     ///
-    /// Peer address is actual socket address, if proxy is used in front of
-    /// actix http server, then peer address would be address of this proxy.
+    /// Peer address is the directly connected peer's socket address. If a proxy is used in front of
+    /// the Actix Web server, then it would be address of this proxy.
     ///
     /// To get client connection information `ConnectionInfo` should be used.
+    ///
+    /// Will only return None when called in unit tests.
     #[inline]
     pub fn peer_addr(&self) -> Option<net::SocketAddr> {
         self.head().peer_addr
@@ -192,42 +190,42 @@ impl ServiceRequest {
     /// access the matched value for that segment.
     #[inline]
     pub fn match_info(&self) -> &Path<Url> {
-        self.0.match_info()
+        self.req.match_info()
     }
 
-    /// Counterpart to [`HttpRequest::match_name`](../struct.HttpRequest.html#method.match_name).
+    /// Counterpart to [`HttpRequest::match_name`](super::HttpRequest::match_name()).
     #[inline]
     pub fn match_name(&self) -> Option<&str> {
-        self.0.match_name()
+        self.req.match_name()
     }
 
-    /// Counterpart to [`HttpRequest::match_pattern`](../struct.HttpRequest.html#method.match_pattern).
+    /// Counterpart to [`HttpRequest::match_pattern`](super::HttpRequest::match_pattern()).
     #[inline]
     pub fn match_pattern(&self) -> Option<String> {
-        self.0.match_pattern()
+        self.req.match_pattern()
     }
 
     #[inline]
     /// Get a mutable reference to the Path parameters.
     pub fn match_info_mut(&mut self) -> &mut Path<Url> {
-        self.0.match_info_mut()
+        self.req.match_info_mut()
     }
 
     #[inline]
     /// Get a reference to a `ResourceMap` of current application.
     pub fn resource_map(&self) -> &ResourceMap {
-        self.0.resource_map()
+        self.req.resource_map()
     }
 
     /// Service configuration
     #[inline]
     pub fn app_config(&self) -> &AppConfig {
-        self.0.app_config()
+        self.req.app_config()
     }
 
-    /// Counterpart to [`HttpRequest::app_data`](../struct.HttpRequest.html#method.app_data).
+    /// Counterpart to [`HttpRequest::app_data`](super::HttpRequest::app_data()).
     pub fn app_data<T: 'static>(&self) -> Option<&T> {
-        for container in (self.0).0.app_data.iter().rev() {
+        for container in self.req.inner.app_data.iter().rev() {
             if let Some(data) = container.get::<T>() {
                 return Some(data);
             }
@@ -238,13 +236,15 @@ impl ServiceRequest {
 
     /// Set request payload.
     pub fn set_payload(&mut self, payload: Payload) {
-        Rc::get_mut(&mut (self.0).0).unwrap().payload = payload;
+        self.payload = payload;
     }
 
-    #[doc(hidden)]
-    /// Add app data container to request's resolution set.
+    /// Add data container to request's resolution set.
+    ///
+    /// In middleware, prefer [`extensions_mut`](ServiceRequest::extensions_mut) for request-local
+    /// data since it is assumed that the same app data is presented for every request.
     pub fn add_data_container(&mut self, extensions: Rc<Extensions>) {
-        Rc::get_mut(&mut (self.0).0)
+        Rc::get_mut(&mut (self.req).inner)
             .unwrap()
             .app_data
             .push(extensions);
@@ -269,18 +269,18 @@ impl HttpMessage for ServiceRequest {
     /// Request extensions
     #[inline]
     fn extensions(&self) -> Ref<'_, Extensions> {
-        self.0.extensions()
+        self.req.extensions()
     }
 
     /// Mutable reference to a the request's extensions
     #[inline]
     fn extensions_mut(&self) -> RefMut<'_, Extensions> {
-        self.0.extensions_mut()
+        self.req.extensions_mut()
     }
 
     #[inline]
     fn take_payload(&mut self) -> Payload<Self::Stream> {
-        Rc::get_mut(&mut (self.0).0).unwrap().payload.take()
+        self.payload.take()
     }
 }
 
@@ -412,9 +412,9 @@ impl<B> ServiceResponse<B> {
     }
 }
 
-impl<B> Into<Response<B>> for ServiceResponse<B> {
-    fn into(self) -> Response<B> {
-        self.response
+impl<B> From<ServiceResponse<B>> for Response<B> {
+    fn from(res: ServiceResponse<B>) -> Response<B> {
+        res.response
     }
 }
 
@@ -486,10 +486,10 @@ impl WebService {
     /// Set a service factory implementation and generate web service.
     pub fn finish<T, F>(self, service: F) -> impl HttpServiceFactory
     where
-        F: IntoServiceFactory<T>,
+        F: IntoServiceFactory<T, ServiceRequest>,
         T: ServiceFactory<
+                ServiceRequest,
                 Config = (),
-                Request = ServiceRequest,
                 Response = ServiceResponse,
                 Error = Error,
                 InitError = (),
@@ -514,8 +514,8 @@ struct WebServiceImpl<T> {
 impl<T> HttpServiceFactory for WebServiceImpl<T>
 where
     T: ServiceFactory<
+            ServiceRequest,
             Config = (),
-            Request = ServiceRequest,
             Response = ServiceResponse,
             Error = Error,
             InitError = (),
@@ -540,6 +540,65 @@ where
     }
 }
 
+/// Macro helping register different types of services at the sametime.
+///
+/// The service type must be implementing [`HttpServiceFactory`](self::HttpServiceFactory) trait.
+///
+/// The max number of services can be grouped together is 12.
+///
+/// # Examples
+///
+/// ```
+/// use actix_web::{services, web, App};
+///
+/// let services = services![
+///     web::resource("/test2").to(|| async { "test2" }),
+///     web::scope("/test3").route("/", web::get().to(|| async { "test3" }))
+/// ];
+///
+/// let app = App::new().service(services);
+///
+/// // services macro just convert multiple services to a tuple.
+/// // below would also work without importing the macro.
+/// let app = App::new().service((
+///     web::resource("/test2").to(|| async { "test2" }),
+///     web::scope("/test3").route("/", web::get().to(|| async { "test3" }))
+/// ));
+/// ```
+#[macro_export]
+macro_rules! services {
+    ($($x:expr),+ $(,)?) => {
+        ($($x,)+)
+    }
+}
+
+/// HttpServiceFactory trait impl for tuples
+macro_rules! service_tuple ({ $(($n:tt, $T:ident)),+} => {
+    impl<$($T: HttpServiceFactory),+> HttpServiceFactory for ($($T,)+) {
+        fn register(self, config: &mut AppService) {
+            $(self.$n.register(config);)+
+        }
+    }
+});
+
+#[rustfmt::skip]
+mod m {
+    use super::*;
+
+    service_tuple!((0, A));
+    service_tuple!((0, A), (1, B));
+    service_tuple!((0, A), (1, B), (2, C));
+    service_tuple!((0, A), (1, B), (2, C), (3, D));
+    service_tuple!((0, A), (1, B), (2, C), (3, D), (4, E));
+    service_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F));
+    service_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G));
+    service_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H));
+    service_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H), (8, I));
+    service_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H), (8, I), (9, J));
+    service_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H), (8, I), (9, J), (10, K));
+    service_tuple!((0, A), (1, B), (2, C), (3, D), (4, E), (5, F), (6, G), (7, H), (8, I), (9, J), (10, K), (11, L));
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -548,30 +607,9 @@ mod tests {
     use actix_service::Service;
     use futures_util::future::ok;
 
-    #[test]
-    fn test_service_request() {
-        let req = TestRequest::default().to_srv_request();
-        let (r, pl) = req.into_parts();
-        assert!(ServiceRequest::from_parts(r, pl).is_ok());
-
-        let req = TestRequest::default().to_srv_request();
-        let (r, pl) = req.into_parts();
-        let _r2 = r.clone();
-        assert!(ServiceRequest::from_parts(r, pl).is_err());
-
-        let req = TestRequest::default().to_srv_request();
-        let (r, _pl) = req.into_parts();
-        assert!(ServiceRequest::from_request(r).is_ok());
-
-        let req = TestRequest::default().to_srv_request();
-        let (r, _pl) = req.into_parts();
-        let _r2 = r.clone();
-        assert!(ServiceRequest::from_request(r).is_err());
-    }
-
     #[actix_rt::test]
     async fn test_service() {
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(web::service("/test").name("test").finish(
                 |req: ServiceRequest| ok(req.into_response(HttpResponse::Ok().finish())),
             )),
@@ -581,7 +619,7 @@ mod tests {
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), http::StatusCode::OK);
 
-        let mut srv = init_service(
+        let srv = init_service(
             App::new().service(web::service("/test").guard(guard::Get()).finish(
                 |req: ServiceRequest| ok(req.into_response(HttpResponse::Ok().finish())),
             )),
@@ -596,20 +634,18 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_service_data() {
-        let mut srv = init_service(
-            App::new()
-                .data(42u32)
-                .service(web::service("/test").name("test").finish(
-                    |req: ServiceRequest| {
-                        assert_eq!(
-                            req.app_data::<web::Data<u32>>().unwrap().as_ref(),
-                            &42
-                        );
-                        ok(req.into_response(HttpResponse::Ok().finish()))
-                    },
-                )),
-        )
-        .await;
+        let srv =
+            init_service(
+                App::new()
+                    .data(42u32)
+                    .service(web::service("/test").name("test").finish(
+                        |req: ServiceRequest| {
+                            assert_eq!(req.app_data::<web::Data<u32>>().unwrap().as_ref(), &42);
+                            ok(req.into_response(HttpResponse::Ok().finish()))
+                        },
+                    )),
+            )
+            .await;
         let req = TestRequest::with_uri("/test").to_request();
         let resp = srv.call(req).await.unwrap();
         assert_eq!(resp.status(), http::StatusCode::OK);
@@ -619,14 +655,14 @@ mod tests {
     fn test_fmt_debug() {
         let req = TestRequest::get()
             .uri("/index.html?test=1")
-            .header("x-test", "111")
+            .insert_header(("x-test", "111"))
             .to_srv_request();
         let s = format!("{:?}", req);
         assert!(s.contains("ServiceRequest"));
         assert!(s.contains("test=1"));
         assert!(s.contains("x-test"));
 
-        let res = HttpResponse::Ok().header("x-test", "111").finish();
+        let res = HttpResponse::Ok().insert_header(("x-test", "111")).finish();
         let res = TestRequest::post()
             .uri("/index.html?test=1")
             .to_srv_response(res);
@@ -635,4 +671,80 @@ mod tests {
         assert!(s.contains("ServiceResponse"));
         assert!(s.contains("x-test"));
     }
+
+    #[actix_rt::test]
+    async fn test_services_macro() {
+        let scoped = services![
+            web::service("/scoped_test1").name("scoped_test1").finish(
+                |req: ServiceRequest| async {
+                    Ok(req.into_response(HttpResponse::Ok().finish()))
+                }
+            ),
+            web::resource("/scoped_test2").to(|| async { "test2" }),
+        ];
+
+        let services = services![
+            web::service("/test1")
+                .name("test")
+                .finish(|req: ServiceRequest| async {
+                    Ok(req.into_response(HttpResponse::Ok().finish()))
+                }),
+            web::resource("/test2").to(|| async { "test2" }),
+            web::scope("/test3").service(scoped)
+        ];
+
+        let srv = init_service(App::new().service(services)).await;
+
+        let req = TestRequest::with_uri("/test1").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), http::StatusCode::OK);
+
+        let req = TestRequest::with_uri("/test2").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), http::StatusCode::OK);
+
+        let req = TestRequest::with_uri("/test3/scoped_test1").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), http::StatusCode::OK);
+
+        let req = TestRequest::with_uri("/test3/scoped_test2").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), http::StatusCode::OK);
+    }
+
+    #[actix_rt::test]
+    async fn test_services_vec() {
+        let services = vec![
+            web::resource("/test1").to(|| async { "test1" }),
+            web::resource("/test2").to(|| async { "test2" }),
+        ];
+
+        let scoped = vec![
+            web::resource("/scoped_test1").to(|| async { "test1" }),
+            web::resource("/scoped_test2").to(|| async { "test2" }),
+        ];
+
+        let srv = init_service(
+            App::new()
+                .service(services)
+                .service(web::scope("/test3").service(scoped)),
+        )
+        .await;
+
+        let req = TestRequest::with_uri("/test1").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), http::StatusCode::OK);
+
+        let req = TestRequest::with_uri("/test2").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), http::StatusCode::OK);
+
+        let req = TestRequest::with_uri("/test3/scoped_test1").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), http::StatusCode::OK);
+
+        let req = TestRequest::with_uri("/test3/scoped_test2").to_request();
+        let resp = srv.call(req).await.unwrap();
+        assert_eq!(resp.status(), http::StatusCode::OK);
+    }
 }
diff --git a/src/test.rs b/src/test.rs
index ee51b71ee..dd2426fec 100644
--- a/src/test.rs
+++ b/src/test.rs
@@ -1,20 +1,20 @@
 //! Various helpers for Actix applications to use during testing.
-use std::convert::TryFrom;
+
 use std::net::SocketAddr;
 use std::rc::Rc;
 use std::sync::mpsc;
 use std::{fmt, net, thread, time};
 
 use actix_codec::{AsyncRead, AsyncWrite, Framed};
-use actix_http::http::header::{ContentType, Header, HeaderName, IntoHeaderValue};
-use actix_http::http::{Error as HttpError, Method, StatusCode, Uri, Version};
+#[cfg(feature = "cookies")]
+use actix_http::cookie::Cookie;
+use actix_http::http::header::{ContentType, IntoHeaderPair};
+use actix_http::http::{Method, StatusCode, Uri, Version};
 use actix_http::test::TestRequest as HttpTestRequest;
-use actix_http::{cookie::Cookie, ws, Extensions, HttpService, Request};
+use actix_http::{ws, Extensions, HttpService, Request};
 use actix_router::{Path, ResourceDef, Url};
-use actix_rt::{time::delay_for, System};
-use actix_service::{
-    map_config, IntoService, IntoServiceFactory, Service, ServiceFactory,
-};
+use actix_rt::{time::sleep, System};
+use actix_service::{map_config, IntoService, IntoServiceFactory, Service, ServiceFactory};
 use awc::error::PayloadError;
 use awc::{Client, ClientRequest, ClientResponse, Connector};
 use bytes::{Bytes, BytesMut};
@@ -27,26 +27,24 @@ use socket2::{Domain, Protocol, Socket, Type};
 
 pub use actix_http::test::TestBuffer;
 
+use crate::app_service::AppInitServiceState;
 use crate::config::AppConfig;
 use crate::data::Data;
 use crate::dev::{Body, MessageBody, Payload, Server};
-use crate::request::HttpRequestPool;
 use crate::rmap::ResourceMap;
 use crate::service::{ServiceRequest, ServiceResponse};
 use crate::{Error, HttpRequest, HttpResponse};
 
 /// Create service that always responds with `HttpResponse::Ok()`
 pub fn ok_service(
-) -> impl Service<Request = ServiceRequest, Response = ServiceResponse<Body>, Error = Error>
-{
+) -> impl Service<ServiceRequest, Response = ServiceResponse<Body>, Error = Error> {
     default_service(StatusCode::OK)
 }
 
 /// Create service that responds with response with specified status code
 pub fn default_service(
     status_code: StatusCode,
-) -> impl Service<Request = ServiceRequest, Response = ServiceResponse<Body>, Error = Error>
-{
+) -> impl Service<ServiceRequest, Response = ServiceResponse<Body>, Error = Error> {
     (move |req: ServiceRequest| {
         ok(req.into_response(HttpResponse::build(status_code).finish()))
     })
@@ -62,7 +60,7 @@ pub fn default_service(
 ///
 /// #[actix_rt::test]
 /// async fn test_init_service() {
-///     let mut app = test::init_service(
+///     let app = test::init_service(
 ///         App::new()
 ///             .service(web::resource("/test").to(|| async { HttpResponse::Ok() }))
 ///     ).await;
@@ -77,15 +75,10 @@ pub fn default_service(
 /// ```
 pub async fn init_service<R, S, B, E>(
     app: R,
-) -> impl Service<Request = Request, Response = ServiceResponse<B>, Error = E>
+) -> impl Service<Request, Response = ServiceResponse<B>, Error = E>
 where
-    R: IntoServiceFactory<S>,
-    S: ServiceFactory<
-        Config = AppConfig,
-        Request = Request,
-        Response = ServiceResponse<B>,
-        Error = E,
-    >,
+    R: IntoServiceFactory<S, Request>,
+    S: ServiceFactory<Request, Config = AppConfig, Response = ServiceResponse<B>, Error = E>,
     S::InitError: std::fmt::Debug,
 {
     try_init_service(app)
@@ -96,18 +89,10 @@ where
 /// Fallible version of init_service that allows testing data factory errors.
 pub(crate) async fn try_init_service<R, S, B, E>(
     app: R,
-) -> Result<
-    impl Service<Request = Request, Response = ServiceResponse<B>, Error = E>,
-    S::InitError,
->
+) -> Result<impl Service<Request, Response = ServiceResponse<B>, Error = E>, S::InitError>
 where
-    R: IntoServiceFactory<S>,
-    S: ServiceFactory<
-        Config = AppConfig,
-        Request = Request,
-        Response = ServiceResponse<B>,
-        Error = E,
-    >,
+    R: IntoServiceFactory<S, Request>,
+    S: ServiceFactory<Request, Config = AppConfig, Response = ServiceResponse<B>, Error = E>,
     S::InitError: std::fmt::Debug,
 {
     let srv = app.into_factory();
@@ -121,7 +106,7 @@ where
 ///
 /// #[actix_rt::test]
 /// async fn test_response() {
-///     let mut app = test::init_service(
+///     let app = test::init_service(
 ///         App::new()
 ///             .service(web::resource("/test").to(|| async {
 ///                 HttpResponse::Ok()
@@ -132,13 +117,13 @@ where
 ///     let req = test::TestRequest::with_uri("/test").to_request();
 ///
 ///     // Call application
-///     let resp = test::call_service(&mut app, req).await;
+///     let resp = test::call_service(&app, req).await;
 ///     assert_eq!(resp.status(), StatusCode::OK);
 /// }
 /// ```
-pub async fn call_service<S, R, B, E>(app: &mut S, req: R) -> S::Response
+pub async fn call_service<S, R, B, E>(app: &S, req: R) -> S::Response
 where
-    S: Service<Request = R, Response = ServiceResponse<B>, Error = E>,
+    S: Service<R, Response = ServiceResponse<B>, Error = E>,
     E: std::fmt::Debug,
 {
     app.call(req).await.unwrap()
@@ -152,7 +137,7 @@ where
 ///
 /// #[actix_rt::test]
 /// async fn test_index() {
-///     let mut app = test::init_service(
+///     let app = test::init_service(
 ///         App::new().service(
 ///             web::resource("/index.html")
 ///                 .route(web::post().to(|| async {
@@ -165,13 +150,13 @@ where
 ///         .header(header::CONTENT_TYPE, "application/json")
 ///         .to_request();
 ///
-///     let result = test::read_response(&mut app, req).await;
+///     let result = test::read_response(&app, req).await;
 ///     assert_eq!(result, Bytes::from_static(b"welcome!"));
 /// }
 /// ```
-pub async fn read_response<S, B>(app: &mut S, req: Request) -> Bytes
+pub async fn read_response<S, B>(app: &S, req: Request) -> Bytes
 where
-    S: Service<Request = Request, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<Request, Response = ServiceResponse<B>, Error = Error>,
     B: MessageBody + Unpin,
 {
     let mut resp = app
@@ -195,7 +180,7 @@ where
 ///
 /// #[actix_rt::test]
 /// async fn test_index() {
-///     let mut app = test::init_service(
+///     let app = test::init_service(
 ///         App::new().service(
 ///             web::resource("/index.html")
 ///                 .route(web::post().to(|| async {
@@ -208,7 +193,7 @@ where
 ///         .header(header::CONTENT_TYPE, "application/json")
 ///         .to_request();
 ///
-///     let resp = test::call_service(&mut app, req).await;
+///     let resp = test::call_service(&app, req).await;
 ///     let result = test::read_body(resp).await;
 ///     assert_eq!(result, Bytes::from_static(b"welcome!"));
 /// }
@@ -239,12 +224,12 @@ where
 ///
 /// #[actix_rt::test]
 /// async fn test_post_person() {
-///     let mut app = test::init_service(
+///     let app = test::init_service(
 ///         App::new().service(
 ///             web::resource("/people")
 ///                 .route(web::post().to(|person: web::Json<Person>| async {
 ///                     HttpResponse::Ok()
-///                         .json(person.into_inner())})
+///                         .json(person)})
 ///                     ))
 ///     ).await;
 ///
@@ -270,7 +255,7 @@ where
     let body = read_body(res).await;
 
     serde_json::from_slice(&body)
-        .unwrap_or_else(|_| panic!("read_response_json failed during deserialization"))
+        .unwrap_or_else(|e| panic!("read_response_json failed during deserialization: {}", e))
 }
 
 pub async fn load_stream<S>(mut stream: S) -> Result<Bytes, Error>
@@ -298,12 +283,12 @@ where
 ///
 /// #[actix_rt::test]
 /// async fn test_add_person() {
-///     let mut app = test::init_service(
+///     let app = test::init_service(
 ///         App::new().service(
 ///             web::resource("/people")
 ///                 .route(web::post().to(|person: web::Json<Person>| async {
 ///                     HttpResponse::Ok()
-///                         .json(person.into_inner())})
+///                         .json(person)})
 ///                     ))
 ///     ).await;
 ///
@@ -318,9 +303,9 @@ where
 ///     let result: Person = test::read_response_json(&mut app, req).await;
 /// }
 /// ```
-pub async fn read_response_json<S, B, T>(app: &mut S, req: Request) -> T
+pub async fn read_response_json<S, B, T>(app: &S, req: Request) -> T
 where
-    S: Service<Request = Request, Response = ServiceResponse<B>, Error = Error>,
+    S: Service<Request, Response = ServiceResponse<B>, Error = Error>,
     B: MessageBody + Unpin,
     T: DeserializeOwned,
 {
@@ -353,7 +338,7 @@ where
 ///
 /// #[test]
 /// fn test_index() {
-///     let req = test::TestRequest::with_header("content-type", "text/plain")
+///     let req = test::TestRequest::default().insert_header("content-type", "text/plain")
 ///         .to_http_request();
 ///
 ///     let resp = index(req).await.unwrap();
@@ -393,21 +378,6 @@ impl TestRequest {
         TestRequest::default().uri(path)
     }
 
-    /// Create TestRequest and set header
-    pub fn with_hdr<H: Header>(hdr: H) -> TestRequest {
-        TestRequest::default().set(hdr)
-    }
-
-    /// Create TestRequest and set header
-    pub fn with_header<K, V>(key: K, value: V) -> TestRequest
-    where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
-    {
-        TestRequest::default().header(key, value)
-    }
-
     /// Create TestRequest and set method to `Method::GET`
     pub fn get() -> TestRequest {
         TestRequest::default().method(Method::GET)
@@ -451,24 +421,26 @@ impl TestRequest {
         self
     }
 
-    /// Set a header
-    pub fn set<H: Header>(mut self, hdr: H) -> Self {
-        self.req.set(hdr);
-        self
-    }
-
-    /// Set a header
-    pub fn header<K, V>(mut self, key: K, value: V) -> Self
+    /// Insert a header, replacing any that were set with an equivalent field name.
+    pub fn insert_header<H>(mut self, header: H) -> Self
     where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
+        H: IntoHeaderPair,
     {
-        self.req.header(key, value);
+        self.req.insert_header(header);
         self
     }
 
-    /// Set cookie for this request
+    /// Append a header, keeping any that were set with an equivalent field name.
+    pub fn append_header<H>(mut self, header: H) -> Self
+    where
+        H: IntoHeaderPair,
+    {
+        self.req.append_header(header);
+        self
+    }
+
+    /// Set cookie for this request.
+    #[cfg(feature = "cookies")]
     pub fn cookie(mut self, cookie: Cookie<'_>) -> Self {
         self.req.cookie(cookie);
         self
@@ -498,17 +470,16 @@ impl TestRequest {
         let bytes = serde_urlencoded::to_string(data)
             .expect("Failed to serialize test data as a urlencoded form");
         self.req.set_payload(bytes);
-        self.req.set(ContentType::form_url_encoded());
+        self.req.insert_header(ContentType::form_url_encoded());
         self
     }
 
     /// Serialize `data` to JSON and set it as the request payload. The `Content-Type` header is
     /// set to `application/json`.
     pub fn set_json<T: Serialize>(mut self, data: &T) -> Self {
-        let bytes =
-            serde_json::to_string(data).expect("Failed to serialize test data to json");
+        let bytes = serde_json::to_string(data).expect("Failed to serialize test data to json");
         self.req.set_payload(bytes);
-        self.req.set(ContentType::json());
+        self.req.insert_header(ContentType::json());
         self
     }
 
@@ -546,15 +517,12 @@ impl TestRequest {
         head.peer_addr = self.peer_addr;
         self.path.get_mut().update(&head.uri);
 
-        ServiceRequest::new(HttpRequest::new(
-            self.path,
-            head,
+        let app_state = AppInitServiceState::new(Rc::new(self.rmap), self.config.clone());
+
+        ServiceRequest::new(
+            HttpRequest::new(self.path, head, app_state, Rc::new(self.app_data)),
             payload,
-            Rc::new(self.rmap),
-            self.config.clone(),
-            Rc::new(self.app_data),
-            HttpRequestPool::create(),
-        ))
+        )
     }
 
     /// Complete request creation and generate `ServiceResponse` instance
@@ -564,19 +532,13 @@ impl TestRequest {
 
     /// Complete request creation and generate `HttpRequest` instance
     pub fn to_http_request(mut self) -> HttpRequest {
-        let (mut head, payload) = self.req.finish().into_parts();
+        let (mut head, _) = self.req.finish().into_parts();
         head.peer_addr = self.peer_addr;
         self.path.get_mut().update(&head.uri);
 
-        HttpRequest::new(
-            self.path,
-            head,
-            payload,
-            Rc::new(self.rmap),
-            self.config.clone(),
-            Rc::new(self.app_data),
-            HttpRequestPool::create(),
-        )
+        let app_state = AppInitServiceState::new(Rc::new(self.rmap), self.config.clone());
+
+        HttpRequest::new(self.path, head, app_state, Rc::new(self.app_data))
     }
 
     /// Complete request creation and generate `HttpRequest` and `Payload` instances
@@ -585,23 +547,17 @@ impl TestRequest {
         head.peer_addr = self.peer_addr;
         self.path.get_mut().update(&head.uri);
 
-        let req = HttpRequest::new(
-            self.path,
-            head,
-            Payload::None,
-            Rc::new(self.rmap),
-            self.config.clone(),
-            Rc::new(self.app_data),
-            HttpRequestPool::create(),
-        );
+        let app_state = AppInitServiceState::new(Rc::new(self.rmap), self.config.clone());
+
+        let req = HttpRequest::new(self.path, head, app_state, Rc::new(self.app_data));
 
         (req, payload)
     }
 
     /// Complete request creation, calls service and waits for response future completion.
-    pub async fn send_request<S, B, E>(self, app: &mut S) -> S::Response
+    pub async fn send_request<S, B, E>(self, app: &S) -> S::Response
     where
-        S: Service<Request = Request, Response = ServiceResponse<B>, Error = E>,
+        S: Service<Request, Response = ServiceResponse<B>, Error = E>,
         E: std::fmt::Debug,
     {
         let req = self.to_request();
@@ -625,7 +581,7 @@ impl TestRequest {
 ///
 /// #[actix_rt::test]
 /// async fn test_example() {
-///     let mut srv = test::start(
+///     let srv = test::start(
 ///         || App::new().service(
 ///                 web::resource("/").to(my_handler))
 ///     );
@@ -638,12 +594,12 @@ impl TestRequest {
 pub fn start<F, I, S, B>(factory: F) -> TestServer
 where
     F: Fn() -> I + Send + Clone + 'static,
-    I: IntoServiceFactory<S>,
-    S: ServiceFactory<Config = AppConfig, Request = Request> + 'static,
+    I: IntoServiceFactory<S, Request>,
+    S: ServiceFactory<Request, Config = AppConfig> + 'static,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
     S::Response: Into<HttpResponse<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
 {
     start_with(TestServerConfig::default(), factory)
@@ -665,7 +621,7 @@ where
 ///
 /// #[actix_rt::test]
 /// async fn test_example() {
-///     let mut srv = test::start_with(test::config().h1(), ||
+///     let srv = test::start_with(test::config().h1(), ||
 ///         App::new().service(web::resource("/").to(my_handler))
 ///     );
 ///
@@ -677,12 +633,12 @@ where
 pub fn start_with<F, I, S, B>(cfg: TestServerConfig, factory: F) -> TestServer
 where
     F: Fn() -> I + Send + Clone + 'static,
-    I: IntoServiceFactory<S>,
-    S: ServiceFactory<Config = AppConfig, Request = Request> + 'static,
+    I: IntoServiceFactory<S, Request>,
+    S: ServiceFactory<Request, Config = AppConfig> + 'static,
     S::Error: Into<Error> + 'static,
     S::InitError: fmt::Debug,
     S::Response: Into<HttpResponse<B>> + 'static,
-    <S::Service as Service>::Future: 'static,
+    <S::Service as Service<Request>>::Future: 'static,
     B: MessageBody + 'static,
 {
     let (tx, rx) = mpsc::channel();
@@ -697,7 +653,7 @@ where
 
     // run server in separate thread
     thread::spawn(move || {
-        let sys = System::new("actix-test-server");
+        let sys = System::new();
         let tcp = net::TcpListener::bind("127.0.0.1:0").unwrap();
         let local_addr = tcp.local_addr().unwrap();
         let factory = factory.clone();
@@ -708,24 +664,21 @@ where
         let srv = match cfg.stream {
             StreamType::Tcp => match cfg.tp {
                 HttpVer::Http1 => builder.listen("test", tcp, move || {
-                    let cfg =
-                        AppConfig::new(false, local_addr, format!("{}", local_addr));
+                    let cfg = AppConfig::new(false, local_addr, format!("{}", local_addr));
                     HttpService::build()
                         .client_timeout(ctimeout)
                         .h1(map_config(factory(), move |_| cfg.clone()))
                         .tcp()
                 }),
                 HttpVer::Http2 => builder.listen("test", tcp, move || {
-                    let cfg =
-                        AppConfig::new(false, local_addr, format!("{}", local_addr));
+                    let cfg = AppConfig::new(false, local_addr, format!("{}", local_addr));
                     HttpService::build()
                         .client_timeout(ctimeout)
                         .h2(map_config(factory(), move |_| cfg.clone()))
                         .tcp()
                 }),
                 HttpVer::Both => builder.listen("test", tcp, move || {
-                    let cfg =
-                        AppConfig::new(false, local_addr, format!("{}", local_addr));
+                    let cfg = AppConfig::new(false, local_addr, format!("{}", local_addr));
                     HttpService::build()
                         .client_timeout(ctimeout)
                         .finish(map_config(factory(), move |_| cfg.clone()))
@@ -735,24 +688,21 @@ where
             #[cfg(feature = "openssl")]
             StreamType::Openssl(acceptor) => match cfg.tp {
                 HttpVer::Http1 => builder.listen("test", tcp, move || {
-                    let cfg =
-                        AppConfig::new(true, local_addr, format!("{}", local_addr));
+                    let cfg = AppConfig::new(true, local_addr, format!("{}", local_addr));
                     HttpService::build()
                         .client_timeout(ctimeout)
                         .h1(map_config(factory(), move |_| cfg.clone()))
                         .openssl(acceptor.clone())
                 }),
                 HttpVer::Http2 => builder.listen("test", tcp, move || {
-                    let cfg =
-                        AppConfig::new(true, local_addr, format!("{}", local_addr));
+                    let cfg = AppConfig::new(true, local_addr, format!("{}", local_addr));
                     HttpService::build()
                         .client_timeout(ctimeout)
                         .h2(map_config(factory(), move |_| cfg.clone()))
                         .openssl(acceptor.clone())
                 }),
                 HttpVer::Both => builder.listen("test", tcp, move || {
-                    let cfg =
-                        AppConfig::new(true, local_addr, format!("{}", local_addr));
+                    let cfg = AppConfig::new(true, local_addr, format!("{}", local_addr));
                     HttpService::build()
                         .client_timeout(ctimeout)
                         .finish(map_config(factory(), move |_| cfg.clone()))
@@ -762,24 +712,21 @@ where
             #[cfg(feature = "rustls")]
             StreamType::Rustls(config) => match cfg.tp {
                 HttpVer::Http1 => builder.listen("test", tcp, move || {
-                    let cfg =
-                        AppConfig::new(true, local_addr, format!("{}", local_addr));
+                    let cfg = AppConfig::new(true, local_addr, format!("{}", local_addr));
                     HttpService::build()
                         .client_timeout(ctimeout)
                         .h1(map_config(factory(), move |_| cfg.clone()))
                         .rustls(config.clone())
                 }),
                 HttpVer::Http2 => builder.listen("test", tcp, move || {
-                    let cfg =
-                        AppConfig::new(true, local_addr, format!("{}", local_addr));
+                    let cfg = AppConfig::new(true, local_addr, format!("{}", local_addr));
                     HttpService::build()
                         .client_timeout(ctimeout)
                         .h2(map_config(factory(), move |_| cfg.clone()))
                         .rustls(config.clone())
                 }),
                 HttpVer::Both => builder.listen("test", tcp, move || {
-                    let cfg =
-                        AppConfig::new(true, local_addr, format!("{}", local_addr));
+                    let cfg = AppConfig::new(true, local_addr, format!("{}", local_addr));
                     HttpService::build()
                         .client_timeout(ctimeout)
                         .finish(map_config(factory(), move |_| cfg.clone()))
@@ -787,10 +734,13 @@ where
                 }),
             },
         }
-        .unwrap()
-        .start();
+        .unwrap();
+
+        sys.block_on(async {
+            let srv = srv.run();
+            tx.send((System::current(), srv, local_addr)).unwrap();
+        });
 
-        tx.send((System::current(), srv, local_addr)).unwrap();
         sys.run()
     });
 
@@ -800,7 +750,7 @@ where
         let connector = {
             #[cfg(feature = "openssl")]
             {
-                use open_ssl::ssl::{SslConnector, SslMethod, SslVerifyMode};
+                use openssl::ssl::{SslConnector, SslMethod, SslVerifyMode};
 
                 let mut builder = SslConnector::builder(SslMethod::tls()).unwrap();
                 builder.set_verify(SslVerifyMode::NONE);
@@ -811,14 +761,12 @@ where
                     .conn_lifetime(time::Duration::from_secs(0))
                     .timeout(time::Duration::from_millis(30000))
                     .ssl(builder.build())
-                    .finish()
             }
             #[cfg(not(feature = "openssl"))]
             {
                 Connector::new()
                     .conn_lifetime(time::Duration::from_secs(0))
                     .timeout(time::Duration::from_millis(30000))
-                    .finish()
             }
         };
 
@@ -852,9 +800,9 @@ enum HttpVer {
 enum StreamType {
     Tcp,
     #[cfg(feature = "openssl")]
-    Openssl(open_ssl::ssl::SslAcceptor),
+    Openssl(openssl::ssl::SslAcceptor),
     #[cfg(feature = "rustls")]
-    Rustls(rust_tls::ServerConfig),
+    Rustls(rustls::ServerConfig),
 }
 
 impl Default for TestServerConfig {
@@ -878,13 +826,13 @@ impl TestServerConfig {
         }
     }
 
-    /// Start http/1.1 server only
+    /// Start HTTP/1.1 server only
     pub fn h1(mut self) -> Self {
         self.tp = HttpVer::Http1;
         self
     }
 
-    /// Start http/2 server only
+    /// Start HTTP/2 server only
     pub fn h2(mut self) -> Self {
         self.tp = HttpVer::Http2;
         self
@@ -892,14 +840,14 @@ impl TestServerConfig {
 
     /// Start openssl server
     #[cfg(feature = "openssl")]
-    pub fn openssl(mut self, acceptor: open_ssl::ssl::SslAcceptor) -> Self {
+    pub fn openssl(mut self, acceptor: openssl::ssl::SslAcceptor) -> Self {
         self.stream = StreamType::Openssl(acceptor);
         self
     }
 
     /// Start rustls server
     #[cfg(feature = "rustls")]
-    pub fn rustls(mut self, config: rust_tls::ServerConfig) -> Self {
+    pub fn rustls(mut self, config: rustls::ServerConfig) -> Self {
         self.stream = StreamType::Rustls(config);
         self
     }
@@ -914,8 +862,7 @@ impl TestServerConfig {
 /// Get first available unused address
 pub fn unused_addr() -> net::SocketAddr {
     let addr: net::SocketAddr = "127.0.0.1:0".parse().unwrap();
-    let socket =
-        Socket::new(Domain::ipv4(), Type::stream(), Some(Protocol::tcp())).unwrap();
+    let socket = Socket::new(Domain::ipv4(), Type::stream(), Some(Protocol::tcp())).unwrap();
     socket.bind(&addr.into()).unwrap();
     socket.set_reuse_address(true).unwrap();
     let tcp = socket.into_tcp_listener();
@@ -983,7 +930,7 @@ impl TestServer {
         self.client.options(self.url(path.as_ref()).as_str())
     }
 
-    /// Connect to test http server
+    /// Connect to test HTTP server
     pub fn request<S: AsRef<str>>(&self, method: Method, path: S) -> ClientRequest {
         self.client.request(method, path.as_ref())
     }
@@ -998,30 +945,28 @@ impl TestServer {
         response.body().limit(10_485_760).await
     }
 
-    /// Connect to websocket server at a given path
+    /// Connect to WebSocket server at a given path.
     pub async fn ws_at(
         &mut self,
         path: &str,
-    ) -> Result<Framed<impl AsyncRead + AsyncWrite, ws::Codec>, awc::error::WsClientError>
-    {
+    ) -> Result<Framed<impl AsyncRead + AsyncWrite, ws::Codec>, awc::error::WsClientError> {
         let url = self.url(path);
         let connect = self.client.ws(url).connect();
         connect.await.map(|(_, framed)| framed)
     }
 
-    /// Connect to a websocket server
+    /// Connect to a WebSocket server.
     pub async fn ws(
         &mut self,
-    ) -> Result<Framed<impl AsyncRead + AsyncWrite, ws::Codec>, awc::error::WsClientError>
-    {
+    ) -> Result<Framed<impl AsyncRead + AsyncWrite, ws::Codec>, awc::error::WsClientError> {
         self.ws_at("/").await
     }
 
-    /// Gracefully stop http server
+    /// Gracefully stop HTTP server
     pub async fn stop(self) {
         self.server.stop(true).await;
         self.system.stop();
-        delay_for(time::Duration::from_millis(100)).await;
+        sleep(time::Duration::from_millis(100)).await;
     }
 }
 
@@ -1033,7 +978,7 @@ impl Drop for TestServer {
 
 #[cfg(test)]
 mod tests {
-    use actix_http::httpmessage::HttpMessage;
+    use actix_http::HttpMessage;
     use serde::{Deserialize, Serialize};
     use std::time::SystemTime;
 
@@ -1042,9 +987,10 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_basics() {
-        let req = TestRequest::with_hdr(header::ContentType::json())
+        let req = TestRequest::default()
             .version(Version::HTTP_2)
-            .set(header::Date(SystemTime::now().into()))
+            .insert_header(header::ContentType::json())
+            .insert_header(header::Date(SystemTime::now().into()))
             .param("test", "123")
             .data(10u32)
             .app_data(20u64)
@@ -1069,7 +1015,7 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_request_methods() {
-        let mut app = init_service(
+        let app = init_service(
             App::new().service(
                 web::resource("/index.html")
                     .route(web::put().to(|| HttpResponse::Ok().body("put!")))
@@ -1081,28 +1027,28 @@ mod tests {
 
         let put_req = TestRequest::put()
             .uri("/index.html")
-            .header(header::CONTENT_TYPE, "application/json")
+            .insert_header((header::CONTENT_TYPE, "application/json"))
             .to_request();
 
-        let result = read_response(&mut app, put_req).await;
+        let result = read_response(&app, put_req).await;
         assert_eq!(result, Bytes::from_static(b"put!"));
 
         let patch_req = TestRequest::patch()
             .uri("/index.html")
-            .header(header::CONTENT_TYPE, "application/json")
+            .insert_header((header::CONTENT_TYPE, "application/json"))
             .to_request();
 
-        let result = read_response(&mut app, patch_req).await;
+        let result = read_response(&app, patch_req).await;
         assert_eq!(result, Bytes::from_static(b"patch!"));
 
         let delete_req = TestRequest::delete().uri("/index.html").to_request();
-        let result = read_response(&mut app, delete_req).await;
+        let result = read_response(&app, delete_req).await;
         assert_eq!(result, Bytes::from_static(b"delete!"));
     }
 
     #[actix_rt::test]
     async fn test_response() {
-        let mut app = init_service(
+        let app = init_service(
             App::new().service(
                 web::resource("/index.html")
                     .route(web::post().to(|| HttpResponse::Ok().body("welcome!"))),
@@ -1112,16 +1058,16 @@ mod tests {
 
         let req = TestRequest::post()
             .uri("/index.html")
-            .header(header::CONTENT_TYPE, "application/json")
+            .insert_header((header::CONTENT_TYPE, "application/json"))
             .to_request();
 
-        let result = read_response(&mut app, req).await;
+        let result = read_response(&app, req).await;
         assert_eq!(result, Bytes::from_static(b"welcome!"));
     }
 
     #[actix_rt::test]
     async fn test_send_request() {
-        let mut app = init_service(
+        let app = init_service(
             App::new().service(
                 web::resource("/index.html")
                     .route(web::get().to(|| HttpResponse::Ok().body("welcome!"))),
@@ -1131,7 +1077,7 @@ mod tests {
 
         let resp = TestRequest::get()
             .uri("/index.html")
-            .send_request(&mut app)
+            .send_request(&app)
             .await;
 
         let result = read_body(resp).await;
@@ -1146,10 +1092,8 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_response_json() {
-        let mut app = init_service(App::new().service(web::resource("/people").route(
-            web::post().to(|person: web::Json<Person>| {
-                HttpResponse::Ok().json(person.into_inner())
-            }),
+        let app = init_service(App::new().service(web::resource("/people").route(
+            web::post().to(|person: web::Json<Person>| HttpResponse::Ok().json(person)),
         )))
         .await;
 
@@ -1157,20 +1101,18 @@ mod tests {
 
         let req = TestRequest::post()
             .uri("/people")
-            .header(header::CONTENT_TYPE, "application/json")
+            .insert_header((header::CONTENT_TYPE, "application/json"))
             .set_payload(payload)
             .to_request();
 
-        let result: Person = read_response_json(&mut app, req).await;
+        let result: Person = read_response_json(&app, req).await;
         assert_eq!(&result.id, "12345");
     }
 
     #[actix_rt::test]
     async fn test_body_json() {
-        let mut app = init_service(App::new().service(web::resource("/people").route(
-            web::post().to(|person: web::Json<Person>| {
-                HttpResponse::Ok().json(person.into_inner())
-            }),
+        let app = init_service(App::new().service(web::resource("/people").route(
+            web::post().to(|person: web::Json<Person>| HttpResponse::Ok().json(person)),
         )))
         .await;
 
@@ -1178,9 +1120,9 @@ mod tests {
 
         let resp = TestRequest::post()
             .uri("/people")
-            .header(header::CONTENT_TYPE, "application/json")
+            .insert_header((header::CONTENT_TYPE, "application/json"))
             .set_payload(payload)
-            .send_request(&mut app)
+            .send_request(&app)
             .await;
 
         let result: Person = read_body_json(resp).await;
@@ -1189,10 +1131,8 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_request_response_form() {
-        let mut app = init_service(App::new().service(web::resource("/people").route(
-            web::post().to(|person: web::Form<Person>| {
-                HttpResponse::Ok().json(person.into_inner())
-            }),
+        let app = init_service(App::new().service(web::resource("/people").route(
+            web::post().to(|person: web::Form<Person>| HttpResponse::Ok().json(person)),
         )))
         .await;
 
@@ -1208,17 +1148,15 @@ mod tests {
 
         assert_eq!(req.content_type(), "application/x-www-form-urlencoded");
 
-        let result: Person = read_response_json(&mut app, req).await;
+        let result: Person = read_response_json(&app, req).await;
         assert_eq!(&result.id, "12345");
         assert_eq!(&result.name, "User name");
     }
 
     #[actix_rt::test]
     async fn test_request_response_json() {
-        let mut app = init_service(App::new().service(web::resource("/people").route(
-            web::post().to(|person: web::Json<Person>| {
-                HttpResponse::Ok().json(person.into_inner())
-            }),
+        let app = init_service(App::new().service(web::resource("/people").route(
+            web::post().to(|person: web::Json<Person>| HttpResponse::Ok().json(person)),
         )))
         .await;
 
@@ -1234,7 +1172,7 @@ mod tests {
 
         assert_eq!(req.content_type(), "application/json");
 
-        let result: Person = read_response_json(&mut app, req).await;
+        let result: Person = read_response_json(&app, req).await;
         assert_eq!(&result.id, "12345");
         assert_eq!(&result.name, "User name");
     }
@@ -1247,15 +1185,14 @@ mod tests {
             match res {
                 Ok(value) => Ok(HttpResponse::Ok()
                     .content_type("text/plain")
-                    .body(format!("Async with block value: {}", value))),
+                    .body(format!("Async with block value: {:?}", value))),
                 Err(_) => panic!("Unexpected"),
             }
         }
 
-        let mut app = init_service(
-            App::new().service(web::resource("/index.html").to(async_with_block)),
-        )
-        .await;
+        let app =
+            init_service(App::new().service(web::resource("/index.html").to(async_with_block)))
+                .await;
 
         let req = TestRequest::post().uri("/index.html").to_request();
         let res = app.call(req).await.unwrap();
@@ -1269,7 +1206,7 @@ mod tests {
             HttpResponse::Ok()
         }
 
-        let mut app = init_service(
+        let app = init_service(
             App::new()
                 .data(10usize)
                 .service(web::resource("/index.html").to(handler)),
@@ -1280,55 +1217,4 @@ mod tests {
         let res = app.call(req).await.unwrap();
         assert!(res.status().is_success());
     }
-
-    #[actix_rt::test]
-    async fn test_actor() {
-        use crate::Error;
-        use actix::prelude::*;
-
-        struct MyActor;
-
-        impl Actor for MyActor {
-            type Context = Context<Self>;
-        }
-
-        struct Num(usize);
-
-        impl Message for Num {
-            type Result = usize;
-        }
-
-        impl Handler<Num> for MyActor {
-            type Result = usize;
-
-            fn handle(&mut self, msg: Num, _: &mut Self::Context) -> Self::Result {
-                msg.0
-            }
-        }
-
-        let addr = MyActor.start();
-
-        async fn actor_handler(
-            addr: Data<Addr<MyActor>>,
-        ) -> Result<impl Responder, Error> {
-            // `?` operator tests "actors" feature flag on actix-http
-            let res = addr.send(Num(1)).await?;
-
-            if res == 1 {
-                Ok(HttpResponse::Ok())
-            } else {
-                Ok(HttpResponse::BadRequest())
-            }
-        }
-
-        let srv = App::new()
-            .data(addr.clone())
-            .service(web::resource("/").to(actor_handler));
-
-        let mut app = init_service(srv).await;
-
-        let req = TestRequest::post().uri("/").to_request();
-        let res = app.call(req).await.unwrap();
-        assert!(res.status().is_success());
-    }
 }
diff --git a/src/types/either.rs b/src/types/either.rs
new file mode 100644
index 000000000..bbab48dec
--- /dev/null
+++ b/src/types/either.rs
@@ -0,0 +1,306 @@
+//! For either helper, see [`Either`].
+
+use bytes::Bytes;
+use futures_util::{future::LocalBoxFuture, FutureExt, TryFutureExt};
+
+use crate::{
+    dev,
+    web::{Form, Json},
+    Error, FromRequest, HttpRequest, HttpResponse, Responder,
+};
+
+/// Combines two extractor or responder types into a single type.
+///
+/// Can be converted to and from an [`either::Either`].
+///
+/// # Extractor
+/// Provides a mechanism for trying two extractors, a primary and a fallback. Useful for
+/// "polymorphic payloads" where, for example, a form might be JSON or URL encoded.
+///
+/// It is important to note that this extractor, by necessity, buffers the entire request payload
+/// as part of its implementation. Though, it does respect any `PayloadConfig` maximum size limits.
+///
+/// ```
+/// use actix_web::{post, web, Either};
+/// use serde::Deserialize;
+///
+/// #[derive(Deserialize)]
+/// struct Info {
+///     name: String,
+/// }
+///
+/// // handler that accepts form as JSON or form-urlencoded.
+/// #[post("/")]
+/// async fn index(form: Either<web::Json<Info>, web::Form<Info>>) -> String {
+///     let name: String = match form {
+///         Either::Left(json) => json.name.to_owned(),
+///         Either::Right(form) => form.name.to_owned(),
+///     };
+///
+///     format!("Welcome {}!", name)
+/// }
+/// ```
+///
+/// # Responder
+/// It may be desireable to use a concrete type for a response with multiple branches. As long as
+/// both types implement `Responder`, so will the `Either` type, enabling it to be used as a
+/// handler's return type.
+///
+/// All properties of a response are determined by the Responder branch returned.
+///
+/// ```
+/// use actix_web::{get, Either, Error, HttpResponse};
+///
+/// #[get("/")]
+/// async fn index() -> Either<&'static str, Result<HttpResponse, Error>> {
+///     if 1 == 2 {
+///         // respond with Left variant
+///         Either::Left("Bad data")
+///     } else {
+///         // respond with Right variant
+///         Either::Right(
+///             Ok(HttpResponse::Ok()
+///                 .content_type(mime::TEXT_HTML)
+///                 .body("<p>Hello!</p>"))
+///         )
+///     }
+/// }
+/// ```
+#[derive(Debug, PartialEq)]
+pub enum Either<L, R> {
+    /// A value of type `L`.
+    Left(L),
+
+    /// A value of type `R`.
+    Right(R),
+}
+
+impl<T> Either<Form<T>, Json<T>> {
+    pub fn into_inner(self) -> T {
+        match self {
+            Either::Left(form) => form.into_inner(),
+            Either::Right(form) => form.into_inner(),
+        }
+    }
+}
+
+impl<T> Either<Json<T>, Form<T>> {
+    pub fn into_inner(self) -> T {
+        match self {
+            Either::Left(form) => form.into_inner(),
+            Either::Right(form) => form.into_inner(),
+        }
+    }
+}
+
+impl<L, R> From<either::Either<L, R>> for Either<L, R> {
+    fn from(val: either::Either<L, R>) -> Self {
+        match val {
+            either::Either::Left(l) => Either::Left(l),
+            either::Either::Right(r) => Either::Right(r),
+        }
+    }
+}
+
+impl<L, R> From<Either<L, R>> for either::Either<L, R> {
+    fn from(val: Either<L, R>) -> Self {
+        match val {
+            Either::Left(l) => either::Either::Left(l),
+            Either::Right(r) => either::Either::Right(r),
+        }
+    }
+}
+
+#[cfg(test)]
+impl<L, R> Either<L, R> {
+    pub(self) fn unwrap_left(self) -> L {
+        match self {
+            Either::Left(data) => data,
+            Either::Right(_) => {
+                panic!("Cannot unwrap Left branch. Either contains an `R` type.")
+            }
+        }
+    }
+
+    pub(self) fn unwrap_right(self) -> R {
+        match self {
+            Either::Left(_) => {
+                panic!("Cannot unwrap Right branch. Either contains an `L` type.")
+            }
+            Either::Right(data) => data,
+        }
+    }
+}
+
+/// See [here](#responder) for example of usage as a handler return type.
+impl<L, R> Responder for Either<L, R>
+where
+    L: Responder,
+    R: Responder,
+{
+    fn respond_to(self, req: &HttpRequest) -> HttpResponse {
+        match self {
+            Either::Left(a) => a.respond_to(req),
+            Either::Right(b) => b.respond_to(req),
+        }
+    }
+}
+
+/// A composite error resulting from failure to extract an `Either<L, R>`.
+///
+/// The implementation of `Into<actix_web::Error>` will return the payload buffering error or the
+/// error from the primary extractor. To access the fallback error, use a match clause.
+#[derive(Debug)]
+pub enum EitherExtractError<L, R> {
+    /// Error from payload buffering, such as exceeding payload max size limit.
+    Bytes(Error),
+
+    /// Error from primary extractor.
+    Extract(L, R),
+}
+
+impl<L, R> From<EitherExtractError<L, R>> for Error
+where
+    L: Into<Error>,
+    R: Into<Error>,
+{
+    fn from(err: EitherExtractError<L, R>) -> Error {
+        match err {
+            EitherExtractError::Bytes(err) => err,
+            EitherExtractError::Extract(a_err, _b_err) => a_err.into(),
+        }
+    }
+}
+
+/// See [here](#extractor) for example of usage as an extractor.
+impl<L, R> FromRequest for Either<L, R>
+where
+    L: FromRequest + 'static,
+    R: FromRequest + 'static,
+{
+    type Error = EitherExtractError<L::Error, R::Error>;
+    type Future = LocalBoxFuture<'static, Result<Self, Self::Error>>;
+    type Config = ();
+
+    fn from_request(req: &HttpRequest, payload: &mut dev::Payload) -> Self::Future {
+        let req2 = req.clone();
+
+        Bytes::from_request(req, payload)
+            .map_err(EitherExtractError::Bytes)
+            .and_then(|bytes| bytes_to_l_or_r(req2, bytes))
+            .boxed_local()
+    }
+}
+
+async fn bytes_to_l_or_r<L, R>(
+    req: HttpRequest,
+    bytes: Bytes,
+) -> Result<Either<L, R>, EitherExtractError<L::Error, R::Error>>
+where
+    L: FromRequest + 'static,
+    R: FromRequest + 'static,
+{
+    let fallback = bytes.clone();
+    let a_err;
+
+    let mut pl = payload_from_bytes(bytes);
+    match L::from_request(&req, &mut pl).await {
+        Ok(a_data) => return Ok(Either::Left(a_data)),
+        // store A's error for returning if B also fails
+        Err(err) => a_err = err,
+    };
+
+    let mut pl = payload_from_bytes(fallback);
+    match R::from_request(&req, &mut pl).await {
+        Ok(b_data) => return Ok(Either::Right(b_data)),
+        Err(b_err) => Err(EitherExtractError::Extract(a_err, b_err)),
+    }
+}
+
+fn payload_from_bytes(bytes: Bytes) -> dev::Payload {
+    let (_, mut h1_payload) = actix_http::h1::Payload::create(true);
+    h1_payload.unread_data(bytes);
+    dev::Payload::from(h1_payload)
+}
+
+#[cfg(test)]
+mod tests {
+    use serde::{Deserialize, Serialize};
+
+    use super::*;
+    use crate::{
+        test::TestRequest,
+        web::{Form, Json},
+    };
+
+    #[derive(Debug, Clone, Serialize, Deserialize)]
+    struct TestForm {
+        hello: String,
+    }
+
+    #[actix_rt::test]
+    async fn test_either_extract_first_try() {
+        let (req, mut pl) = TestRequest::default()
+            .set_form(&TestForm {
+                hello: "world".to_owned(),
+            })
+            .to_http_parts();
+
+        let form = Either::<Form<TestForm>, Json<TestForm>>::from_request(&req, &mut pl)
+            .await
+            .unwrap()
+            .unwrap_left()
+            .into_inner();
+        assert_eq!(&form.hello, "world");
+    }
+
+    #[actix_rt::test]
+    async fn test_either_extract_fallback() {
+        let (req, mut pl) = TestRequest::default()
+            .set_json(&TestForm {
+                hello: "world".to_owned(),
+            })
+            .to_http_parts();
+
+        let form = Either::<Form<TestForm>, Json<TestForm>>::from_request(&req, &mut pl)
+            .await
+            .unwrap()
+            .unwrap_right()
+            .into_inner();
+        assert_eq!(&form.hello, "world");
+    }
+
+    #[actix_rt::test]
+    async fn test_either_extract_recursive_fallback() {
+        let (req, mut pl) = TestRequest::default()
+            .set_payload(Bytes::from_static(b"!@$%^&*()"))
+            .to_http_parts();
+
+        let payload = Either::<Either<Form<TestForm>, Json<TestForm>>, Bytes>::from_request(
+            &req, &mut pl,
+        )
+        .await
+        .unwrap()
+        .unwrap_right();
+        assert_eq!(&payload.as_ref(), &b"!@$%^&*()");
+    }
+
+    #[actix_rt::test]
+    async fn test_either_extract_recursive_fallback_inner() {
+        let (req, mut pl) = TestRequest::default()
+            .set_json(&TestForm {
+                hello: "world".to_owned(),
+            })
+            .to_http_parts();
+
+        let form = Either::<Either<Form<TestForm>, Json<TestForm>>, Bytes>::from_request(
+            &req, &mut pl,
+        )
+        .await
+        .unwrap()
+        .unwrap_left()
+        .unwrap_right()
+        .into_inner();
+        assert_eq!(&form.hello, "world");
+    }
+}
diff --git a/src/types/form.rs b/src/types/form.rs
index 2a7101287..0b5c3c1b4 100644
--- a/src/types/form.rs
+++ b/src/types/form.rs
@@ -1,72 +1,68 @@
-//! Form extractor
+//! For URL encoded form helper documentation, see [`Form`].
 
-use std::future::Future;
-use std::pin::Pin;
-use std::rc::Rc;
-use std::task::{Context, Poll};
-use std::{fmt, ops};
+use std::{
+    fmt,
+    future::Future,
+    ops,
+    pin::Pin,
+    rc::Rc,
+    task::{Context, Poll},
+};
 
-use actix_http::{Error, HttpMessage, Payload, Response};
+use actix_http::Payload;
 use bytes::BytesMut;
 use encoding_rs::{Encoding, UTF_8};
-use futures_util::future::{err, ok, FutureExt, LocalBoxFuture, Ready};
-use futures_util::StreamExt;
-use serde::de::DeserializeOwned;
-use serde::Serialize;
+use futures_util::{
+    future::{FutureExt, LocalBoxFuture},
+    StreamExt,
+};
+use serde::{de::DeserializeOwned, Serialize};
 
 #[cfg(feature = "compress")]
 use crate::dev::Decompress;
-use crate::error::UrlencodedError;
-use crate::extract::FromRequest;
-use crate::http::{
-    header::{ContentType, CONTENT_LENGTH},
-    StatusCode,
+use crate::{
+    error::UrlencodedError, extract::FromRequest, http::header::CONTENT_LENGTH, web, Error,
+    HttpMessage, HttpRequest, HttpResponse, Responder,
 };
-use crate::request::HttpRequest;
-use crate::{responder::Responder, web};
 
-/// Form data helper (`application/x-www-form-urlencoded`)
+/// URL encoded payload extractor and responder.
 ///
-/// Can be use to extract url-encoded data from the request body,
-/// or send url-encoded data as the response.
+/// `Form` has two uses: URL encoded responses, and extracting typed data from URL request payloads.
 ///
-/// ## Extract
+/// # Extractor
+/// To extract typed data from a request body, the inner type `T` must implement the
+/// [`serde::Deserialize`] trait.
 ///
-/// To extract typed information from request's body, the type `T` must
-/// implement the `Deserialize` trait from *serde*.
+/// Use [`FormConfig`] to configure extraction process.
 ///
-/// [**FormConfig**](struct.FormConfig.html) allows to configure extraction
-/// process.
-///
-/// ### Example
-/// ```rust
-/// use actix_web::web;
-/// use serde_derive::Deserialize;
+/// ```
+/// use actix_web::{post, web};
+/// use serde::Deserialize;
 ///
 /// #[derive(Deserialize)]
-/// struct FormData {
-///     username: String,
+/// struct Info {
+///     name: String,
 /// }
 ///
-/// /// Extract form data using serde.
-/// /// This handler get called only if content type is *x-www-form-urlencoded*
-/// /// and content of the request could be deserialized to a `FormData` struct
-/// fn index(form: web::Form<FormData>) -> String {
-///     format!("Welcome {}!", form.username)
+/// // This handler is only called if:
+/// // - request headers declare the content type as `application/x-www-form-urlencoded`
+/// // - request payload is deserialized into a `Info` struct from the URL encoded format
+/// #[post("/")]
+/// async fn index(form: web::Form<Info>) -> String {
+///     format!("Welcome {}!", form.name)
 /// }
-/// # fn main() {}
 /// ```
 ///
-/// ## Respond
+/// # Responder
+/// The `Form` type also allows you to create URL encoded responses:
+/// simply return a value of type Form<T> where T is the type to be URL encoded.
+/// The type  must implement [`serde::Serialize`].
 ///
-/// The `Form` type also allows you to respond with well-formed url-encoded data:
-/// simply return a value of type Form<T> where T is the type to be url-encoded.
-/// The type  must implement `serde::Serialize`;
+/// Responses use
 ///
-/// ### Example
-/// ```rust
-/// use actix_web::*;
-/// use serde_derive::Serialize;
+/// ```
+/// use actix_web::{get, web};
+/// use serde::Serialize;
 ///
 /// #[derive(Serialize)]
 /// struct SomeForm {
@@ -74,22 +70,23 @@ use crate::{responder::Responder, web};
 ///     age: u8
 /// }
 ///
-/// // Will return a 200 response with header
-/// // `Content-Type: application/x-www-form-urlencoded`
-/// // and body "name=actix&age=123"
-/// fn index() -> web::Form<SomeForm> {
+/// // Response will have:
+/// // - status: 200 OK
+/// // - header: `Content-Type: application/x-www-form-urlencoded`
+/// // - body: `name=actix&age=123`
+/// #[get("/")]
+/// async fn index() -> web::Form<SomeForm> {
 ///     web::Form(SomeForm {
 ///         name: "actix".into(),
 ///         age: 123
 ///     })
 /// }
-/// # fn main() {}
 /// ```
 #[derive(PartialEq, Eq, PartialOrd, Ord)]
 pub struct Form<T>(pub T);
 
 impl<T> Form<T> {
-    /// Deconstruct to an inner value
+    /// Unwrap into inner `T` value.
     pub fn into_inner(self) -> T {
         self.0
     }
@@ -109,6 +106,7 @@ impl<T> ops::DerefMut for Form<T> {
     }
 }
 
+/// See [here](#extractor) for example of usage as an extractor.
 impl<T> FromRequest for Form<T>
 where
     T: DeserializeOwned + 'static,
@@ -120,7 +118,7 @@ where
     #[inline]
     fn from_request(req: &HttpRequest, payload: &mut Payload) -> Self::Future {
         let req2 = req.clone();
-        let (limit, err) = req
+        let (limit, err_handler) = req
             .app_data::<Self::Config>()
             .or_else(|| {
                 req.app_data::<web::Data<Self::Config>>()
@@ -132,13 +130,10 @@ where
         UrlEncoded::new(req, payload)
             .limit(limit)
             .map(move |res| match res {
-                Err(e) => {
-                    if let Some(err) = err {
-                        Err((*err)(e, &req2))
-                    } else {
-                        Err(e.into())
-                    }
-                }
+                Err(err) => match err_handler {
+                    Some(err_handler) => Err((err_handler)(err, &req2)),
+                    None => Err(err.into()),
+                },
                 Ok(item) => Ok(Form(item)),
             })
             .boxed_local()
@@ -157,49 +152,39 @@ impl<T: fmt::Display> fmt::Display for Form<T> {
     }
 }
 
+/// See [here](#responder) for example of usage as a handler return type.
 impl<T: Serialize> Responder for Form<T> {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        let body = match serde_urlencoded::to_string(&self.0) {
-            Ok(body) => body,
-            Err(e) => return err(e.into()),
-        };
-
-        ok(Response::build(StatusCode::OK)
-            .set(ContentType::form_url_encoded())
-            .body(body))
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        match serde_urlencoded::to_string(&self.0) {
+            Ok(body) => HttpResponse::Ok()
+                .content_type(mime::APPLICATION_WWW_FORM_URLENCODED)
+                .body(body),
+            Err(err) => HttpResponse::from_error(err.into()),
+        }
     }
 }
 
-/// Form extractor configuration
+/// [`Form`] extractor configuration.
 ///
-/// ```rust
-/// use actix_web::{web, App, FromRequest, Result};
-/// use serde_derive::Deserialize;
+/// ```
+/// use actix_web::{post, web, App, FromRequest, Result};
+/// use serde::Deserialize;
 ///
 /// #[derive(Deserialize)]
-/// struct FormData {
+/// struct Info {
 ///     username: String,
 /// }
 ///
-/// /// Extract form data using serde.
-/// /// Custom configuration is used for this handler, max payload size is 4k
-/// async fn index(form: web::Form<FormData>) -> Result<String> {
+/// // Custom `FormConfig` is applied to App.
+/// // Max payload size for URL encoded forms is set to 4kB.
+/// #[post("/")]
+/// async fn index(form: web::Form<Info>) -> Result<String> {
 ///     Ok(format!("Welcome {}!", form.username))
 /// }
 ///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/index.html")
-///             // change `Form` extractor configuration
-///             .app_data(
-///                 web::FormConfig::default().limit(4097)
-///             )
-///             .route(web::get().to(index))
-///     );
-/// }
+/// App::new()
+///     .app_data(web::FormConfig::default().limit(4096))
+///     .service(index);
 /// ```
 #[derive(Clone)]
 pub struct FormConfig {
@@ -208,7 +193,7 @@ pub struct FormConfig {
 }
 
 impl FormConfig {
-    /// Change max size of payload. By default max size is 16Kb
+    /// Set maximum accepted payload size. By default this limit is 16kB.
     pub fn limit(mut self, limit: usize) -> Self {
         self.limit = limit;
         self
@@ -233,33 +218,30 @@ impl Default for FormConfig {
     }
 }
 
-/// Future that resolves to a parsed urlencoded values.
+/// Future that resolves to some `T` when parsed from a URL encoded payload.
 ///
-/// Parse `application/x-www-form-urlencoded` encoded request's body.
-/// Return `UrlEncoded` future. Form can be deserialized to any type that
-/// implements `Deserialize` trait from *serde*.
+/// Form can be deserialized from any type `T` that implements [`serde::Deserialize`].
 ///
-/// Returns error:
-///
-/// * content type is not `application/x-www-form-urlencoded`
-/// * content-length is greater than 32k
-///
-pub struct UrlEncoded<U> {
+/// Returns error if:
+/// - content type is not `application/x-www-form-urlencoded`
+/// - content length is greater than [limit](UrlEncoded::limit())
+pub struct UrlEncoded<T> {
     #[cfg(feature = "compress")]
     stream: Option<Decompress<Payload>>,
     #[cfg(not(feature = "compress"))]
     stream: Option<Payload>,
+
     limit: usize,
     length: Option<usize>,
     encoding: &'static Encoding,
     err: Option<UrlencodedError>,
-    fut: Option<LocalBoxFuture<'static, Result<U, UrlencodedError>>>,
+    fut: Option<LocalBoxFuture<'static, Result<T, UrlencodedError>>>,
 }
 
 #[allow(clippy::borrow_interior_mutable_const)]
-impl<U> UrlEncoded<U> {
-    /// Create a new future to URL encode a request
-    pub fn new(req: &HttpRequest, payload: &mut Payload) -> UrlEncoded<U> {
+impl<T> UrlEncoded<T> {
+    /// Create a new future to decode a URL encoded request payload.
+    pub fn new(req: &HttpRequest, payload: &mut Payload) -> Self {
         // check content type
         if req.content_type().to_lowercase() != "application/x-www-form-urlencoded" {
             return Self::err(UrlencodedError::ContentType);
@@ -297,29 +279,29 @@ impl<U> UrlEncoded<U> {
         }
     }
 
-    fn err(e: UrlencodedError) -> Self {
+    fn err(err: UrlencodedError) -> Self {
         UrlEncoded {
             stream: None,
             limit: 32_768,
             fut: None,
-            err: Some(e),
+            err: Some(err),
             length: None,
             encoding: UTF_8,
         }
     }
 
-    /// Change max size of payload. By default max size is 256Kb
+    /// Set maximum accepted payload size. The default limit is 256kB.
     pub fn limit(mut self, limit: usize) -> Self {
         self.limit = limit;
         self
     }
 }
 
-impl<U> Future for UrlEncoded<U>
+impl<T> Future for UrlEncoded<T>
 where
-    U: DeserializeOwned + 'static,
+    T: DeserializeOwned + 'static,
 {
-    type Output = Result<U, UrlencodedError>;
+    type Output = Result<T, UrlencodedError>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         if let Some(ref mut fut) = self.fut {
@@ -348,6 +330,7 @@ where
 
                 while let Some(item) = stream.next().await {
                     let chunk = item?;
+
                     if (body.len() + chunk.len()) > limit {
                         return Err(UrlencodedError::Overflow {
                             size: body.len() + chunk.len(),
@@ -359,19 +342,19 @@ where
                 }
 
                 if encoding == UTF_8 {
-                    serde_urlencoded::from_bytes::<U>(&body)
-                        .map_err(|_| UrlencodedError::Parse)
+                    serde_urlencoded::from_bytes::<T>(&body).map_err(|_| UrlencodedError::Parse)
                 } else {
                     let body = encoding
                         .decode_without_bom_handling_and_without_replacement(&body)
                         .map(|s| s.into_owned())
                         .ok_or(UrlencodedError::Parse)?;
-                    serde_urlencoded::from_str::<U>(&body)
-                        .map_err(|_| UrlencodedError::Parse)
+
+                    serde_urlencoded::from_str::<T>(&body).map_err(|_| UrlencodedError::Parse)
                 }
             }
             .boxed_local(),
         );
+
         self.poll(cx)
     }
 }
@@ -382,7 +365,10 @@ mod tests {
     use serde::{Deserialize, Serialize};
 
     use super::*;
-    use crate::http::header::{HeaderValue, CONTENT_LENGTH, CONTENT_TYPE};
+    use crate::http::{
+        header::{HeaderValue, CONTENT_LENGTH, CONTENT_TYPE},
+        StatusCode,
+    };
     use crate::test::TestRequest;
 
     #[derive(Deserialize, Serialize, Debug, PartialEq)]
@@ -393,11 +379,11 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_form() {
-        let (req, mut pl) =
-            TestRequest::with_header(CONTENT_TYPE, "application/x-www-form-urlencoded")
-                .header(CONTENT_LENGTH, "11")
-                .set_payload(Bytes::from_static(b"hello=world&counter=123"))
-                .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .insert_header((CONTENT_LENGTH, 11))
+            .set_payload(Bytes::from_static(b"hello=world&counter=123"))
+            .to_http_parts();
 
         let Form(s) = Form::<Info>::from_request(&req, &mut pl).await.unwrap();
         assert_eq!(
@@ -426,25 +412,26 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_urlencoded_error() {
-        let (req, mut pl) =
-            TestRequest::with_header(CONTENT_TYPE, "application/x-www-form-urlencoded")
-                .header(CONTENT_LENGTH, "xxxx")
-                .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .insert_header((CONTENT_LENGTH, "xxxx"))
+            .to_http_parts();
         let info = UrlEncoded::<Info>::new(&req, &mut pl).await;
         assert!(eq(info.err().unwrap(), UrlencodedError::UnknownLength));
 
-        let (req, mut pl) =
-            TestRequest::with_header(CONTENT_TYPE, "application/x-www-form-urlencoded")
-                .header(CONTENT_LENGTH, "1000000")
-                .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .insert_header((CONTENT_LENGTH, "1000000"))
+            .to_http_parts();
         let info = UrlEncoded::<Info>::new(&req, &mut pl).await;
         assert!(eq(
             info.err().unwrap(),
             UrlencodedError::Overflow { size: 0, limit: 0 }
         ));
 
-        let (req, mut pl) = TestRequest::with_header(CONTENT_TYPE, "text/plain")
-            .header(CONTENT_LENGTH, "10")
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((CONTENT_TYPE, "text/plain"))
+            .insert_header((CONTENT_LENGTH, 10))
             .to_http_parts();
         let info = UrlEncoded::<Info>::new(&req, &mut pl).await;
         assert!(eq(info.err().unwrap(), UrlencodedError::ContentType));
@@ -452,11 +439,11 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_urlencoded() {
-        let (req, mut pl) =
-            TestRequest::with_header(CONTENT_TYPE, "application/x-www-form-urlencoded")
-                .header(CONTENT_LENGTH, "11")
-                .set_payload(Bytes::from_static(b"hello=world&counter=123"))
-                .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .insert_header((CONTENT_LENGTH, 11))
+            .set_payload(Bytes::from_static(b"hello=world&counter=123"))
+            .to_http_parts();
 
         let info = UrlEncoded::<Info>::new(&req, &mut pl).await.unwrap();
         assert_eq!(
@@ -467,13 +454,14 @@ mod tests {
             }
         );
 
-        let (req, mut pl) = TestRequest::with_header(
-            CONTENT_TYPE,
-            "application/x-www-form-urlencoded; charset=utf-8",
-        )
-        .header(CONTENT_LENGTH, "11")
-        .set_payload(Bytes::from_static(b"hello=world&counter=123"))
-        .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((
+                CONTENT_TYPE,
+                "application/x-www-form-urlencoded; charset=utf-8",
+            ))
+            .insert_header((CONTENT_LENGTH, 11))
+            .set_payload(Bytes::from_static(b"hello=world&counter=123"))
+            .to_http_parts();
 
         let info = UrlEncoded::<Info>::new(&req, &mut pl).await.unwrap();
         assert_eq!(
@@ -493,7 +481,7 @@ mod tests {
             hello: "world".to_string(),
             counter: 123,
         });
-        let resp = form.respond_to(&req).await.unwrap();
+        let resp = form.respond_to(&req);
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(CONTENT_TYPE).unwrap(),
@@ -509,8 +497,8 @@ mod tests {
         let ctype = HeaderValue::from_static("application/x-www-form-urlencoded");
 
         let (req, mut pl) = TestRequest::default()
-            .header(CONTENT_TYPE, ctype)
-            .header(CONTENT_LENGTH, HeaderValue::from_static("20"))
+            .insert_header((CONTENT_TYPE, ctype))
+            .insert_header((CONTENT_LENGTH, HeaderValue::from_static("20")))
             .set_payload(Bytes::from_static(b"hello=test&counter=4"))
             .app_data(web::Data::new(FormConfig::default().limit(10)))
             .to_http_parts();
@@ -519,6 +507,6 @@ mod tests {
         assert!(s.is_err());
 
         let err_str = s.err().unwrap().to_string();
-        assert!(err_str.contains("Urlencoded payload size is bigger"));
+        assert!(err_str.starts_with("URL encoded payload is larger"));
     }
 }
diff --git a/src/types/json.rs b/src/types/json.rs
index 8da5a3bdb..31ff680f4 100644
--- a/src/types/json.rs
+++ b/src/types/json.rs
@@ -1,44 +1,44 @@
-//! Json extractor/responder
+//! For JSON helper documentation, see [`Json`].
 
-use std::future::Future;
-use std::pin::Pin;
-use std::sync::Arc;
-use std::task::{Context, Poll};
-use std::{fmt, ops};
+use std::{
+    fmt,
+    future::Future,
+    marker::PhantomData,
+    ops,
+    pin::Pin,
+    sync::Arc,
+    task::{Context, Poll},
+};
 
 use bytes::BytesMut;
-use futures_util::future::{err, ok, FutureExt, LocalBoxFuture, Ready};
-use futures_util::StreamExt;
-use serde::de::DeserializeOwned;
-use serde::Serialize;
+use futures_util::{ready, stream::Stream};
+use serde::{de::DeserializeOwned, Serialize};
 
-use actix_http::http::{header::CONTENT_LENGTH, StatusCode};
-use actix_http::{HttpMessage, Payload, Response};
+use actix_http::Payload;
 
 #[cfg(feature = "compress")]
 use crate::dev::Decompress;
-use crate::error::{Error, JsonPayloadError};
-use crate::extract::FromRequest;
-use crate::request::HttpRequest;
-use crate::{responder::Responder, web};
+use crate::{
+    error::{Error, JsonPayloadError},
+    extract::FromRequest,
+    http::header::CONTENT_LENGTH,
+    request::HttpRequest,
+    web, HttpMessage, HttpResponse, Responder,
+};
 
-/// Json helper
+/// JSON extractor and responder.
 ///
-/// Json can be used for two different purpose. First is for json response
-/// generation and second is for extracting typed information from request's
-/// payload.
+/// `Json` has two uses: JSON responses, and extracting typed data from JSON request payloads.
 ///
-/// To extract typed information from request's body, the type `T` must
-/// implement the `Deserialize` trait from *serde*.
+/// # Extractor
+/// To extract typed data from a request body, the inner type `T` must implement the
+/// [`serde::Deserialize`] trait.
 ///
-/// [**JsonConfig**](struct.JsonConfig.html) allows to configure extraction
-/// process.
+/// Use [`JsonConfig`] to configure extraction process.
 ///
-/// ## Example
-///
-/// ```rust
-/// use actix_web::{web, App};
-/// use serde_derive::Deserialize;
+/// ```
+/// use actix_web::{post, web, App};
+/// use serde::Deserialize;
 ///
 /// #[derive(Deserialize)]
 /// struct Info {
@@ -46,43 +46,37 @@ use crate::{responder::Responder, web};
 /// }
 ///
 /// /// deserialize `Info` from request's body
+/// #[post("/")]
 /// async fn index(info: web::Json<Info>) -> String {
 ///     format!("Welcome {}!", info.username)
 /// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///        web::resource("/index.html").route(
-///            web::post().to(index))
-///     );
-/// }
 /// ```
 ///
-/// The `Json` type allows you to respond with well-formed JSON data: simply
-/// return a value of type Json<T> where T is the type of a structure
-/// to serialize into *JSON*. The type `T` must implement the `Serialize`
-/// trait from *serde*.
+/// # Responder
+/// The `Json` type  JSON formatted responses. A handler may return a value of type
+/// `Json<T>` where `T` is the type of a structure to serialize into JSON. The type `T` must
+/// implement [`serde::Serialize`].
 ///
-/// ```rust
-/// use actix_web::*;
-/// use serde_derive::Serialize;
+/// ```
+/// use actix_web::{post, web, HttpRequest};
+/// use serde::Serialize;
 ///
 /// #[derive(Serialize)]
-/// struct MyObj {
+/// struct Info {
 ///     name: String,
 /// }
 ///
-/// fn index(req: HttpRequest) -> Result<web::Json<MyObj>> {
-///     Ok(web::Json(MyObj {
-///         name: req.match_info().get("name").unwrap().to_string(),
-///     }))
+/// #[post("/{name}")]
+/// async fn index(req: HttpRequest) -> web::Json<Info> {
+///     web::Json(Info {
+///         name: req.match_info().get("name").unwrap().to_owned(),
+///     })
 /// }
-/// # fn main() {}
 /// ```
 pub struct Json<T>(pub T);
 
 impl<T> Json<T> {
-    /// Deconstruct to an inner value
+    /// Unwrap into inner `T` value.
     pub fn into_inner(self) -> T {
         self.0
     }
@@ -120,147 +114,135 @@ where
     }
 }
 
+/// Creates response with OK status code, correct content type header, and serialized JSON payload.
+///
+/// If serialization failed
 impl<T: Serialize> Responder for Json<T> {
-    type Error = Error;
-    type Future = Ready<Result<Response, Error>>;
-
-    fn respond_to(self, _: &HttpRequest) -> Self::Future {
-        let body = match serde_json::to_string(&self.0) {
-            Ok(body) => body,
-            Err(e) => return err(e.into()),
-        };
-
-        ok(Response::build(StatusCode::OK)
-            .content_type("application/json")
-            .body(body))
+    fn respond_to(self, _: &HttpRequest) -> HttpResponse {
+        match serde_json::to_string(&self.0) {
+            Ok(body) => HttpResponse::Ok()
+                .content_type(mime::APPLICATION_JSON)
+                .body(body),
+            Err(err) => HttpResponse::from_error(err.into()),
+        }
     }
 }
 
-/// Json extractor. Allow to extract typed information from request's
-/// payload.
-///
-/// To extract typed information from request's body, the type `T` must
-/// implement the `Deserialize` trait from *serde*.
-///
-/// [**JsonConfig**](struct.JsonConfig.html) allows to configure extraction
-/// process.
-///
-/// ## Example
-///
-/// ```rust
-/// use actix_web::{web, App};
-/// use serde_derive::Deserialize;
-///
-/// #[derive(Deserialize)]
-/// struct Info {
-///     username: String,
-/// }
-///
-/// /// deserialize `Info` from request's body
-/// async fn index(info: web::Json<Info>) -> String {
-///     format!("Welcome {}!", info.username)
-/// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/index.html").route(
-///            web::post().to(index))
-///     );
-/// }
-/// ```
+/// See [here](#extractor) for example of usage as an extractor.
 impl<T> FromRequest for Json<T>
 where
     T: DeserializeOwned + 'static,
 {
     type Error = Error;
-    type Future = LocalBoxFuture<'static, Result<Self, Error>>;
+    type Future = JsonExtractFut<T>;
     type Config = JsonConfig;
 
     #[inline]
     fn from_request(req: &HttpRequest, payload: &mut Payload) -> Self::Future {
-        let req2 = req.clone();
         let config = JsonConfig::from_req(req);
 
         let limit = config.limit;
-        let ctype = config.content_type.clone();
+        let ctype = config.content_type.as_deref();
         let err_handler = config.err_handler.clone();
 
-        JsonBody::new(req, payload, ctype)
-            .limit(limit)
-            .map(move |res| match res {
-                Err(e) => {
-                    log::debug!(
-                        "Failed to deserialize Json from payload. \
-                         Request path: {}",
-                        req2.path()
-                    );
-
-                    if let Some(err) = err_handler {
-                        Err((*err)(e, &req2))
-                    } else {
-                        Err(e.into())
-                    }
-                }
-                Ok(data) => Ok(Json(data)),
-            })
-            .boxed_local()
+        JsonExtractFut {
+            req: Some(req.clone()),
+            fut: JsonBody::new(req, payload, ctype).limit(limit),
+            err_handler,
+        }
     }
 }
 
-/// Json extractor configuration
+type JsonErrorHandler =
+    Option<Arc<dyn Fn(JsonPayloadError, &HttpRequest) -> Error + Send + Sync>>;
+
+pub struct JsonExtractFut<T> {
+    req: Option<HttpRequest>,
+    fut: JsonBody<T>,
+    err_handler: JsonErrorHandler,
+}
+
+impl<T> Future for JsonExtractFut<T>
+where
+    T: DeserializeOwned + 'static,
+{
+    type Output = Result<Json<T>, Error>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.get_mut();
+
+        let res = ready!(Pin::new(&mut this.fut).poll(cx));
+
+        let res = match res {
+            Err(err) => {
+                let req = this.req.take().unwrap();
+                log::debug!(
+                    "Failed to deserialize Json from payload. \
+                         Request path: {}",
+                    req.path()
+                );
+
+                if let Some(err_handler) = this.err_handler.as_ref() {
+                    Err((*err_handler)(err, &req))
+                } else {
+                    Err(err.into())
+                }
+            }
+            Ok(data) => Ok(Json(data)),
+        };
+
+        Poll::Ready(res)
+    }
+}
+
+/// `Json` extractor configuration.
 ///
-/// # Example
-///
-/// ```rust
-/// use actix_web::{error, web, App, FromRequest, HttpResponse};
-/// use serde_derive::Deserialize;
+/// # Examples
+/// ```
+/// use actix_web::{error, post, web, App, FromRequest, HttpResponse};
+/// use serde::Deserialize;
 ///
 /// #[derive(Deserialize)]
 /// struct Info {
-///     username: String,
+///     name: String,
 /// }
 ///
-/// /// deserialize `Info` from request's body, max payload size is 4kb
+/// // `Json` extraction is bound by custom `JsonConfig` applied to App.
+/// #[post("/")]
 /// async fn index(info: web::Json<Info>) -> String {
-///     format!("Welcome {}!", info.username)
+///     format!("Welcome {}!", info.name)
 /// }
 ///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/index.html")
-///             .app_data(
-///                 // Json extractor configuration for this resource.
-///                 web::JsonConfig::default()
-///                     .limit(4096) // Limit request payload size
-///                     .content_type(|mime| {  // <- accept text/plain content type
-///                         mime.type_() == mime::TEXT && mime.subtype() == mime::PLAIN
-///                     })
-///                     .error_handler(|err, req| {  // <- create custom error response
-///                        error::InternalError::from_response(
-///                            err, HttpResponse::Conflict().finish()).into()
-///                     })
-///             )
-///             .route(web::post().to(index))
-///     );
-/// }
+/// // custom `Json` extractor configuration
+/// let json_cfg = web::JsonConfig::default()
+///     // limit request payload size
+///     .limit(4096)
+///     // only accept text/plain content type
+///     .content_type(|mime| mime == mime::TEXT_PLAIN)
+///     // use custom error handler
+///     .error_handler(|err, req| {
+///         error::InternalError::from_response(err, HttpResponse::Conflict().finish()).into()
+///     });
+///
+/// App::new()
+///     .app_data(json_cfg)
+///     .service(index);
 /// ```
-///
 #[derive(Clone)]
 pub struct JsonConfig {
     limit: usize,
-    err_handler:
-        Option<Arc<dyn Fn(JsonPayloadError, &HttpRequest) -> Error + Send + Sync>>,
+    err_handler: JsonErrorHandler,
     content_type: Option<Arc<dyn Fn(mime::Mime) -> bool + Send + Sync>>,
 }
 
 impl JsonConfig {
-    /// Change max size of payload. By default max size is 32Kb
+    /// Set maximum accepted payload size. By default this limit is 32kB.
     pub fn limit(mut self, limit: usize) -> Self {
         self.limit = limit;
         self
     }
 
-    /// Set custom error handler
+    /// Set custom error handler.
     pub fn error_handler<F>(mut self, f: F) -> Self
     where
         F: Fn(JsonPayloadError, &HttpRequest) -> Error + Send + Sync + 'static,
@@ -269,7 +251,7 @@ impl JsonConfig {
         self
     }
 
-    /// Set predicate for allowed content types
+    /// Set predicate for allowed content types.
     pub fn content_type<F>(mut self, predicate: F) -> Self
     where
         F: Fn(mime::Mime) -> bool + Send + Sync + 'static,
@@ -283,11 +265,11 @@ impl JsonConfig {
     fn from_req(req: &HttpRequest) -> &Self {
         req.app_data::<Self>()
             .or_else(|| req.app_data::<web::Data<Self>>().map(|d| d.as_ref()))
-            .unwrap_or_else(|| &DEFAULT_CONFIG)
+            .unwrap_or(&DEFAULT_CONFIG)
     }
 }
 
-// Allow shared refs to default.
+/// Allow shared refs used as default.
 const DEFAULT_CONFIG: JsonConfig = JsonConfig {
     limit: 32_768, // 2^15 bytes, (~32kB)
     err_handler: None,
@@ -300,136 +282,156 @@ impl Default for JsonConfig {
     }
 }
 
-/// Request's payload json parser, it resolves to a deserialized `T` value.
-/// This future could be used with `ServiceRequest` and `ServiceFromRequest`.
+/// Future that resolves to some `T` when parsed from a JSON payload.
 ///
-/// Returns error:
+/// Form can be deserialized from any type `T` that implements [`serde::Deserialize`].
 ///
-/// * content type is not `application/json`
-///   (unless specified in [`JsonConfig`](struct.JsonConfig.html))
-/// * content length is greater than 256k
-pub struct JsonBody<U> {
-    limit: usize,
-    length: Option<usize>,
-    #[cfg(feature = "compress")]
-    stream: Option<Decompress<Payload>>,
-    #[cfg(not(feature = "compress"))]
-    stream: Option<Payload>,
-    err: Option<JsonPayloadError>,
-    fut: Option<LocalBoxFuture<'static, Result<U, JsonPayloadError>>>,
+/// Returns error if:
+/// - content type is not `application/json`
+/// - content length is greater than [limit](JsonBody::limit())
+pub enum JsonBody<T> {
+    Error(Option<JsonPayloadError>),
+    Body {
+        limit: usize,
+        length: Option<usize>,
+        #[cfg(feature = "compress")]
+        payload: Decompress<Payload>,
+        #[cfg(not(feature = "compress"))]
+        payload: Payload,
+        buf: BytesMut,
+        _res: PhantomData<T>,
+    },
 }
 
-impl<U> JsonBody<U>
+impl<T> Unpin for JsonBody<T> {}
+
+impl<T> JsonBody<T>
 where
-    U: DeserializeOwned + 'static,
+    T: DeserializeOwned + 'static,
 {
-    /// Create `JsonBody` for request.
+    /// Create a new future to decode a JSON request payload.
     #[allow(clippy::borrow_interior_mutable_const)]
     pub fn new(
         req: &HttpRequest,
         payload: &mut Payload,
-        ctype: Option<Arc<dyn Fn(mime::Mime) -> bool + Send + Sync>>,
+        ctype: Option<&(dyn Fn(mime::Mime) -> bool + Send + Sync)>,
     ) -> Self {
         // check content-type
         let json = if let Ok(Some(mime)) = req.mime_type() {
             mime.subtype() == mime::JSON
                 || mime.suffix() == Some(mime::JSON)
-                || ctype.as_ref().map_or(false, |predicate| predicate(mime))
+                || ctype.map_or(false, |predicate| predicate(mime))
         } else {
             false
         };
 
         if !json {
-            return JsonBody {
-                limit: 262_144,
-                length: None,
-                stream: None,
-                fut: None,
-                err: Some(JsonPayloadError::ContentType),
-            };
+            return JsonBody::Error(Some(JsonPayloadError::ContentType));
         }
 
-        let len = req
+        let length = req
             .headers()
             .get(&CONTENT_LENGTH)
             .and_then(|l| l.to_str().ok())
             .and_then(|s| s.parse::<usize>().ok());
 
+        // Notice the content_length is not checked against limit of json config here.
+        // As the internal usage always call JsonBody::limit after JsonBody::new.
+        // And limit check to return an error variant of JsonBody happens there.
+
         #[cfg(feature = "compress")]
         let payload = Decompress::from_headers(payload.take(), req.headers());
         #[cfg(not(feature = "compress"))]
         let payload = payload.take();
 
-        JsonBody {
-            limit: 262_144,
-            length: len,
-            stream: Some(payload),
-            fut: None,
-            err: None,
+        JsonBody::Body {
+            limit: 32_768,
+            length,
+            payload,
+            buf: BytesMut::with_capacity(8192),
+            _res: PhantomData,
         }
     }
 
-    /// Change max size of payload. By default max size is 256Kb
-    pub fn limit(mut self, limit: usize) -> Self {
-        self.limit = limit;
-        self
+    /// Set maximum accepted payload size. The default limit is 32kB.
+    pub fn limit(self, limit: usize) -> Self {
+        match self {
+            JsonBody::Body {
+                length,
+                payload,
+                buf,
+                ..
+            } => {
+                if let Some(len) = length {
+                    if len > limit {
+                        return JsonBody::Error(Some(JsonPayloadError::Overflow));
+                    }
+                }
+
+                JsonBody::Body {
+                    limit,
+                    length,
+                    payload,
+                    buf,
+                    _res: PhantomData,
+                }
+            }
+            JsonBody::Error(e) => JsonBody::Error(e),
+        }
     }
 }
 
-impl<U> Future for JsonBody<U>
+impl<T> Future for JsonBody<T>
 where
-    U: DeserializeOwned + 'static,
+    T: DeserializeOwned + 'static,
 {
-    type Output = Result<U, JsonPayloadError>;
+    type Output = Result<T, JsonPayloadError>;
 
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        if let Some(ref mut fut) = self.fut {
-            return Pin::new(fut).poll(cx);
-        }
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.get_mut();
 
-        if let Some(err) = self.err.take() {
-            return Poll::Ready(Err(err));
-        }
-
-        let limit = self.limit;
-        if let Some(len) = self.length.take() {
-            if len > limit {
-                return Poll::Ready(Err(JsonPayloadError::Overflow));
-            }
-        }
-        let mut stream = self.stream.take().unwrap();
-
-        self.fut = Some(
-            async move {
-                let mut body = BytesMut::with_capacity(8192);
-
-                while let Some(item) = stream.next().await {
-                    let chunk = item?;
-                    if (body.len() + chunk.len()) > limit {
-                        return Err(JsonPayloadError::Overflow);
-                    } else {
-                        body.extend_from_slice(&chunk);
+        match this {
+            JsonBody::Body {
+                limit,
+                buf,
+                payload,
+                ..
+            } => loop {
+                let res = ready!(Pin::new(&mut *payload).poll_next(cx));
+                match res {
+                    Some(chunk) => {
+                        let chunk = chunk?;
+                        if (buf.len() + chunk.len()) > *limit {
+                            return Poll::Ready(Err(JsonPayloadError::Overflow));
+                        } else {
+                            buf.extend_from_slice(&chunk);
+                        }
+                    }
+                    None => {
+                        let json = serde_json::from_slice::<T>(&buf)?;
+                        return Poll::Ready(Ok(json));
                     }
                 }
-                Ok(serde_json::from_slice::<U>(&body)?)
-            }
-            .boxed_local(),
-        );
-
-        self.poll(cx)
+            },
+            JsonBody::Error(e) => Poll::Ready(Err(e.take().unwrap())),
+        }
     }
 }
 
 #[cfg(test)]
 mod tests {
     use bytes::Bytes;
-    use serde_derive::{Deserialize, Serialize};
+    use serde::{Deserialize, Serialize};
 
     use super::*;
-    use crate::error::InternalError;
-    use crate::http::header::{self, HeaderValue, CONTENT_LENGTH, CONTENT_TYPE};
-    use crate::test::{load_stream, TestRequest};
-    use crate::HttpResponse;
+    use crate::{
+        error::InternalError,
+        http::{
+            header::{self, CONTENT_LENGTH, CONTENT_TYPE},
+            StatusCode,
+        },
+        test::{load_stream, TestRequest},
+    };
 
     #[derive(Serialize, Deserialize, PartialEq, Debug)]
     struct MyObject {
@@ -453,7 +455,7 @@ mod tests {
         let j = Json(MyObject {
             name: "test".to_string(),
         });
-        let resp = j.respond_to(&req).await.unwrap();
+        let resp = j.respond_to(&req);
         assert_eq!(resp.status(), StatusCode::OK);
         assert_eq!(
             resp.headers().get(header::CONTENT_TYPE).unwrap(),
@@ -467,27 +469,27 @@ mod tests {
     #[actix_rt::test]
     async fn test_custom_error_responder() {
         let (req, mut pl) = TestRequest::default()
-            .header(
+            .insert_header((
                 header::CONTENT_TYPE,
                 header::HeaderValue::from_static("application/json"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONTENT_LENGTH,
                 header::HeaderValue::from_static("16"),
-            )
+            ))
             .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
             .app_data(JsonConfig::default().limit(10).error_handler(|err, _| {
                 let msg = MyObject {
                     name: "invalid request".to_string(),
                 };
-                let resp = HttpResponse::BadRequest()
-                    .body(serde_json::to_string(&msg).unwrap());
+                let resp =
+                    HttpResponse::BadRequest().body(serde_json::to_string(&msg).unwrap());
                 InternalError::from_response(err, resp).into()
             }))
             .to_http_parts();
 
         let s = Json::<MyObject>::from_request(&req, &mut pl).await;
-        let mut resp = Response::from_error(s.err().unwrap());
+        let mut resp = HttpResponse::from_error(s.err().unwrap());
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
 
         let body = load_stream(resp.take_body()).await.unwrap();
@@ -498,14 +500,14 @@ mod tests {
     #[actix_rt::test]
     async fn test_extract() {
         let (req, mut pl) = TestRequest::default()
-            .header(
+            .insert_header((
                 header::CONTENT_TYPE,
                 header::HeaderValue::from_static("application/json"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONTENT_LENGTH,
                 header::HeaderValue::from_static("16"),
-            )
+            ))
             .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
             .to_http_parts();
 
@@ -519,14 +521,14 @@ mod tests {
         );
 
         let (req, mut pl) = TestRequest::default()
-            .header(
+            .insert_header((
                 header::CONTENT_TYPE,
                 header::HeaderValue::from_static("application/json"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONTENT_LENGTH,
                 header::HeaderValue::from_static("16"),
-            )
+            ))
             .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
             .app_data(JsonConfig::default().limit(10))
             .to_http_parts();
@@ -536,14 +538,14 @@ mod tests {
             .contains("Json payload size is bigger than allowed"));
 
         let (req, mut pl) = TestRequest::default()
-            .header(
+            .insert_header((
                 header::CONTENT_TYPE,
                 header::HeaderValue::from_static("application/json"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONTENT_LENGTH,
                 header::HeaderValue::from_static("16"),
-            )
+            ))
             .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
             .app_data(
                 JsonConfig::default()
@@ -562,23 +564,23 @@ mod tests {
         assert!(json_eq(json.err().unwrap(), JsonPayloadError::ContentType));
 
         let (req, mut pl) = TestRequest::default()
-            .header(
+            .insert_header((
                 header::CONTENT_TYPE,
                 header::HeaderValue::from_static("application/text"),
-            )
+            ))
             .to_http_parts();
         let json = JsonBody::<MyObject>::new(&req, &mut pl, None).await;
         assert!(json_eq(json.err().unwrap(), JsonPayloadError::ContentType));
 
         let (req, mut pl) = TestRequest::default()
-            .header(
+            .insert_header((
                 header::CONTENT_TYPE,
                 header::HeaderValue::from_static("application/json"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONTENT_LENGTH,
                 header::HeaderValue::from_static("10000"),
-            )
+            ))
             .to_http_parts();
 
         let json = JsonBody::<MyObject>::new(&req, &mut pl, None)
@@ -587,14 +589,14 @@ mod tests {
         assert!(json_eq(json.err().unwrap(), JsonPayloadError::Overflow));
 
         let (req, mut pl) = TestRequest::default()
-            .header(
+            .insert_header((
                 header::CONTENT_TYPE,
                 header::HeaderValue::from_static("application/json"),
-            )
-            .header(
+            ))
+            .insert_header((
                 header::CONTENT_LENGTH,
                 header::HeaderValue::from_static("16"),
-            )
+            ))
             .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
             .to_http_parts();
 
@@ -609,17 +611,18 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_with_json_and_bad_content_type() {
-        let (req, mut pl) = TestRequest::with_header(
-            header::CONTENT_TYPE,
-            header::HeaderValue::from_static("text/plain"),
-        )
-        .header(
-            header::CONTENT_LENGTH,
-            header::HeaderValue::from_static("16"),
-        )
-        .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
-        .app_data(JsonConfig::default().limit(4096))
-        .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((
+                header::CONTENT_TYPE,
+                header::HeaderValue::from_static("text/plain"),
+            ))
+            .insert_header((
+                header::CONTENT_LENGTH,
+                header::HeaderValue::from_static("16"),
+            ))
+            .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
+            .app_data(JsonConfig::default().limit(4096))
+            .to_http_parts();
 
         let s = Json::<MyObject>::from_request(&req, &mut pl).await;
         assert!(s.is_err())
@@ -627,19 +630,20 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_with_json_and_good_custom_content_type() {
-        let (req, mut pl) = TestRequest::with_header(
-            header::CONTENT_TYPE,
-            header::HeaderValue::from_static("text/plain"),
-        )
-        .header(
-            header::CONTENT_LENGTH,
-            header::HeaderValue::from_static("16"),
-        )
-        .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
-        .app_data(JsonConfig::default().content_type(|mime: mime::Mime| {
-            mime.type_() == mime::TEXT && mime.subtype() == mime::PLAIN
-        }))
-        .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((
+                header::CONTENT_TYPE,
+                header::HeaderValue::from_static("text/plain"),
+            ))
+            .insert_header((
+                header::CONTENT_LENGTH,
+                header::HeaderValue::from_static("16"),
+            ))
+            .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
+            .app_data(JsonConfig::default().content_type(|mime: mime::Mime| {
+                mime.type_() == mime::TEXT && mime.subtype() == mime::PLAIN
+            }))
+            .to_http_parts();
 
         let s = Json::<MyObject>::from_request(&req, &mut pl).await;
         assert!(s.is_ok())
@@ -647,19 +651,20 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_with_json_and_bad_custom_content_type() {
-        let (req, mut pl) = TestRequest::with_header(
-            header::CONTENT_TYPE,
-            header::HeaderValue::from_static("text/html"),
-        )
-        .header(
-            header::CONTENT_LENGTH,
-            header::HeaderValue::from_static("16"),
-        )
-        .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
-        .app_data(JsonConfig::default().content_type(|mime: mime::Mime| {
-            mime.type_() == mime::TEXT && mime.subtype() == mime::PLAIN
-        }))
-        .to_http_parts();
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((
+                header::CONTENT_TYPE,
+                header::HeaderValue::from_static("text/html"),
+            ))
+            .insert_header((
+                header::CONTENT_LENGTH,
+                header::HeaderValue::from_static("16"),
+            ))
+            .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
+            .app_data(JsonConfig::default().content_type(|mime: mime::Mime| {
+                mime.type_() == mime::TEXT && mime.subtype() == mime::PLAIN
+            }))
+            .to_http_parts();
 
         let s = Json::<MyObject>::from_request(&req, &mut pl).await;
         assert!(s.is_err())
@@ -668,8 +673,8 @@ mod tests {
     #[actix_rt::test]
     async fn test_with_config_in_data_wrapper() {
         let (req, mut pl) = TestRequest::default()
-            .header(CONTENT_TYPE, HeaderValue::from_static("application/json"))
-            .header(CONTENT_LENGTH, HeaderValue::from_static("16"))
+            .insert_header((CONTENT_TYPE, mime::APPLICATION_JSON))
+            .insert_header((CONTENT_LENGTH, 16))
             .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
             .app_data(web::Data::new(JsonConfig::default().limit(10)))
             .to_http_parts();
diff --git a/src/types/mod.rs b/src/types/mod.rs
index b32711e2a..a062c351e 100644
--- a/src/types/mod.rs
+++ b/src/types/mod.rs
@@ -1,5 +1,7 @@
-//! Helper types
+//! Common extractors and responders.
 
+// TODO: review visibility
+mod either;
 pub(crate) mod form;
 pub(crate) mod json;
 mod path;
@@ -7,6 +9,7 @@ pub(crate) mod payload;
 mod query;
 pub(crate) mod readlines;
 
+pub use self::either::{Either, EitherExtractError};
 pub use self::form::{Form, FormConfig};
 pub use self::json::{Json, JsonConfig};
 pub use self::path::{Path, PathConfig};
diff --git a/src/types/path.rs b/src/types/path.rs
index dbb5f3ee0..4ab124d53 100644
--- a/src/types/path.rs
+++ b/src/types/path.rs
@@ -1,70 +1,55 @@
-//! Path extractor
-use std::sync::Arc;
-use std::{fmt, ops};
+//! For path segment extractor documentation, see [`Path`].
+
+use std::{fmt, ops, sync::Arc};
 
 use actix_http::error::{Error, ErrorNotFound};
 use actix_router::PathDeserializer;
 use futures_util::future::{ready, Ready};
 use serde::de;
 
-use crate::dev::Payload;
-use crate::error::PathError;
-use crate::request::HttpRequest;
-use crate::FromRequest;
+use crate::{dev::Payload, error::PathError, FromRequest, HttpRequest};
 
-#[derive(PartialEq, Eq, PartialOrd, Ord)]
-/// Extract typed information from the request's path.
+/// Extract typed data from request path segments.
 ///
-/// [**PathConfig**](struct.PathConfig.html) allows to configure extraction process.
+/// Use [`PathConfig`] to configure extraction process.
 ///
-/// ## Example
+/// # Examples
+/// ```
+/// use actix_web::{get, web};
 ///
-/// ```rust
-/// use actix_web::{web, App};
-///
-/// /// extract path info from "/{username}/{count}/index.html" url
-/// /// {username} - deserializes to a String
-/// /// {count} -  - deserializes to a u32
-/// async fn index(web::Path((username, count)): web::Path<(String, u32)>) -> String {
-///     format!("Welcome {}! {}", username, count)
-/// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/{username}/{count}/index.html") // <- define path parameters
-///              .route(web::get().to(index))               // <- register handler with `Path` extractor
-///     );
+/// // extract path info from "/{name}/{count}/index.html" into tuple
+/// // {name}  - deserialize a String
+/// // {count} - deserialize a u32
+/// #[get("/")]
+/// async fn index(path: web::Path<(String, u32)>) -> String {
+///     let (name, count) = path.into_inner();
+///     format!("Welcome {}! {}", name, count)
 /// }
 /// ```
 ///
-/// It is possible to extract path information to a specific type that
-/// implements `Deserialize` trait from *serde*.
+/// Path segments also can be deserialized into any type that implements [`serde::Deserialize`].
+/// Path segment labels will be matched with struct field names.
 ///
-/// ```rust
-/// use actix_web::{web, App, Error};
-/// use serde_derive::Deserialize;
+/// ```
+/// use actix_web::{get, web};
+/// use serde::Deserialize;
 ///
 /// #[derive(Deserialize)]
 /// struct Info {
-///     username: String,
+///     name: String,
 /// }
 ///
-/// /// extract `Info` from a path using serde
-/// async fn index(info: web::Path<Info>) -> Result<String, Error> {
-///     Ok(format!("Welcome {}!", info.username))
-/// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/{username}/index.html") // <- define path parameters
-///              .route(web::get().to(index)) // <- use handler with Path` extractor
-///     );
+/// // extract `Info` from a path using serde
+/// #[get("/")]
+/// async fn index(info: web::Path<Info>) -> String {
+///     format!("Welcome {}!", info.name)
 /// }
 /// ```
-pub struct Path<T>(pub T);
+#[derive(PartialEq, Eq, PartialOrd, Ord)]
+pub struct Path<T>(T);
 
 impl<T> Path<T> {
-    /// Deconstruct to an inner value
+    /// Unwrap into inner `T` value.
     pub fn into_inner(self) -> T {
         self.0
     }
@@ -108,52 +93,7 @@ impl<T: fmt::Display> fmt::Display for Path<T> {
     }
 }
 
-/// Extract typed information from the request's path.
-///
-/// ## Example
-///
-/// ```rust
-/// use actix_web::{web, App};
-///
-/// /// extract path info from "/{username}/{count}/index.html" url
-/// /// {username} - deserializes to a String
-/// /// {count} -  - deserializes to a u32
-/// async fn index(web::Path((username, count)): web::Path<(String, u32)>) -> String {
-///     format!("Welcome {}! {}", username, count)
-/// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/{username}/{count}/index.html") // <- define path parameters
-///              .route(web::get().to(index)) // <- register handler with `Path` extractor
-///     );
-/// }
-/// ```
-///
-/// It is possible to extract path information to a specific type that
-/// implements `Deserialize` trait from *serde*.
-///
-/// ```rust
-/// use actix_web::{web, App, Error};
-/// use serde_derive::Deserialize;
-///
-/// #[derive(Deserialize)]
-/// struct Info {
-///     username: String,
-/// }
-///
-/// /// extract `Info` from a path using serde
-/// async fn index(info: web::Path<Info>) -> Result<String, Error> {
-///     Ok(format!("Welcome {}!", info.username))
-/// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/{username}/index.html") // <- define path parameters
-///              .route(web::get().to(index)) // <- use handler with Path` extractor
-///     );
-/// }
-/// ```
+/// See [here](#usage) for example of usage as an extractor.
 impl<T> FromRequest for Path<T>
 where
     T: de::DeserializeOwned,
@@ -191,10 +131,10 @@ where
 
 /// Path extractor configuration
 ///
-/// ```rust
+/// ```
 /// use actix_web::web::PathConfig;
 /// use actix_web::{error, web, App, FromRequest, HttpResponse};
-/// use serde_derive::Deserialize;
+/// use serde::Deserialize;
 ///
 /// #[derive(Deserialize, Debug)]
 /// enum Folder {
@@ -249,7 +189,7 @@ impl Default for PathConfig {
 mod tests {
     use actix_router::ResourceDef;
     use derive_more::Display;
-    use serde_derive::Deserialize;
+    use serde::Deserialize;
 
     use super::*;
     use crate::test::TestRequest;
@@ -295,11 +235,9 @@ mod tests {
         assert_eq!(res.1, "user1");
 
         let (Path(a), Path(b)) =
-            <(Path<(String, String)>, Path<(String, String)>)>::from_request(
-                &req, &mut pl,
-            )
-            .await
-            .unwrap();
+            <(Path<(String, String)>, Path<(String, String)>)>::from_request(&req, &mut pl)
+                .await
+                .unwrap();
         assert_eq!(a.0, "name");
         assert_eq!(a.1, "user1");
         assert_eq!(b.0, "name");
@@ -360,11 +298,8 @@ mod tests {
     async fn test_custom_err_handler() {
         let (req, mut pl) = TestRequest::with_uri("/name/user1/")
             .app_data(PathConfig::default().error_handler(|err, _| {
-                error::InternalError::from_response(
-                    err,
-                    HttpResponse::Conflict().finish(),
-                )
-                .into()
+                error::InternalError::from_response(err, HttpResponse::Conflict().finish())
+                    .into()
             }))
             .to_http_parts();
 
diff --git a/src/types/payload.rs b/src/types/payload.rs
index bbdd89525..781347b84 100644
--- a/src/types/payload.rs
+++ b/src/types/payload.rs
@@ -1,55 +1,51 @@
-//! Payload/Bytes/String extractors
-use std::future::Future;
-use std::pin::Pin;
-use std::str;
-use std::task::{Context, Poll};
+//! Basic binary and string payload extractors.
 
-use actix_http::error::{Error, ErrorBadRequest, PayloadError};
-use actix_http::HttpMessage;
+use std::{
+    future::Future,
+    pin::Pin,
+    str,
+    task::{Context, Poll},
+};
+
+use actix_http::error::{ErrorBadRequest, PayloadError};
 use bytes::{Bytes, BytesMut};
-use encoding_rs::UTF_8;
+use encoding_rs::{Encoding, UTF_8};
 use futures_core::stream::Stream;
-use futures_util::future::{err, ok, Either, FutureExt, LocalBoxFuture, Ready};
-use futures_util::StreamExt;
+use futures_util::{
+    future::{ready, Either, ErrInto, Ready, TryFutureExt as _},
+    ready,
+};
 use mime::Mime;
 
-use crate::extract::FromRequest;
-use crate::http::header;
-use crate::request::HttpRequest;
-use crate::{dev, web};
+use crate::{dev, http::header, web, Error, FromRequest, HttpMessage, HttpRequest};
 
-/// Payload extractor returns request 's payload stream.
+/// Extract a request's raw payload stream.
 ///
-/// ## Example
+/// See [`PayloadConfig`] for important notes when using this advanced extractor.
 ///
-/// ```rust
-/// use actix_web::{web, error, App, Error, HttpResponse};
+/// # Examples
+/// ```
 /// use std::future::Future;
-/// use futures_core::stream::Stream;
-/// use futures_util::StreamExt;
-/// /// extract binary data from request
-/// async fn index(mut body: web::Payload) -> Result<HttpResponse, Error>
-/// {
+/// use futures_util::stream::{Stream, StreamExt};
+/// use actix_web::{post, web};
+///
+/// // `body: web::Payload` parameter extracts raw payload stream from request
+/// #[post("/")]
+/// async fn index(mut body: web::Payload) -> actix_web::Result<String> {
+///     // for demonstration only; in a normal case use the `Bytes` extractor
+///     // collect payload stream into a bytes object
 ///     let mut bytes = web::BytesMut::new();
 ///     while let Some(item) = body.next().await {
 ///         bytes.extend_from_slice(&item?);
 ///     }
 ///
-///     format!("Body {:?}!", bytes);
-///     Ok(HttpResponse::Ok().finish())
-/// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/index.html").route(
-///             web::get().to(index))
-///     );
+///     Ok(format!("Request Body Bytes:\n{:?}", bytes))
 /// }
 /// ```
 pub struct Payload(pub crate::dev::Payload);
 
 impl Payload {
-    /// Deconstruct to a inner value
+    /// Unwrap to inner Payload type.
     pub fn into_inner(self) -> crate::dev::Payload {
         self.0
     }
@@ -59,43 +55,12 @@ impl Stream for Payload {
     type Item = Result<Bytes, PayloadError>;
 
     #[inline]
-    fn poll_next(
-        mut self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         Pin::new(&mut self.0).poll_next(cx)
     }
 }
 
-/// Get request's payload stream
-///
-/// ## Example
-///
-/// ```rust
-/// use actix_web::{web, error, App, Error, HttpResponse};
-/// use std::future::Future;
-/// use futures_core::stream::Stream;
-/// use futures_util::StreamExt;
-///
-/// /// extract binary data from request
-/// async fn index(mut body: web::Payload) -> Result<HttpResponse, Error>
-/// {
-///     let mut bytes = web::BytesMut::new();
-///     while let Some(item) = body.next().await {
-///         bytes.extend_from_slice(&item?);
-///     }
-///
-///     format!("Body {:?}!", bytes);
-///     Ok(HttpResponse::Ok().finish())
-/// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/index.html").route(
-///             web::get().to(index))
-///     );
-/// }
-/// ```
+/// See [here](#usage) for example of usage as an extractor.
 impl FromRequest for Payload {
     type Config = PayloadConfig;
     type Error = Error;
@@ -103,55 +68,43 @@ impl FromRequest for Payload {
 
     #[inline]
     fn from_request(_: &HttpRequest, payload: &mut dev::Payload) -> Self::Future {
-        ok(Payload(payload.take()))
+        ready(Ok(Payload(payload.take())))
     }
 }
 
-/// Request binary data from a request's payload.
+/// Extract binary data from a request's payload.
 ///
-/// Loads request's payload and construct Bytes instance.
+/// Collects request payload stream into a [Bytes] instance.
 ///
-/// [**PayloadConfig**](struct.PayloadConfig.html) allows to configure
-/// extraction process.
+/// Use [`PayloadConfig`] to configure extraction process.
 ///
-/// ## Example
-///
-/// ```rust
-/// use bytes::Bytes;
-/// use actix_web::{web, App};
+/// # Examples
+/// ```
+/// use actix_web::{post, web};
 ///
 /// /// extract binary data from request
-/// async fn index(body: Bytes) -> String {
+/// #[post("/")]
+/// async fn index(body: web::Bytes) -> String {
 ///     format!("Body {:?}!", body)
 /// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/index.html").route(
-///             web::get().to(index))
-///     );
-/// }
 /// ```
 impl FromRequest for Bytes {
     type Config = PayloadConfig;
     type Error = Error;
-    type Future = Either<
-        LocalBoxFuture<'static, Result<Bytes, Error>>,
-        Ready<Result<Bytes, Error>>,
-    >;
+    type Future = Either<ErrInto<HttpMessageBody, Error>, Ready<Result<Bytes, Error>>>;
 
     #[inline]
     fn from_request(req: &HttpRequest, payload: &mut dev::Payload) -> Self::Future {
         // allow both Config and Data<Config>
         let cfg = PayloadConfig::from_req(req);
 
-        if let Err(e) = cfg.check_mimetype(req) {
-            return Either::Right(err(e));
+        if let Err(err) = cfg.check_mimetype(req) {
+            return Either::Right(ready(Err(err)));
         }
 
         let limit = cfg.limit;
         let fut = HttpMessageBody::new(req, payload).limit(limit);
-        Either::Left(async move { Ok(fut.await?) }.boxed_local())
+        Either::Left(fut.err_into())
     }
 }
 
@@ -159,79 +112,85 @@ impl FromRequest for Bytes {
 ///
 /// Text extractor automatically decode body according to the request's charset.
 ///
-/// [**PayloadConfig**](struct.PayloadConfig.html) allows to configure
+/// [**PayloadConfig**](PayloadConfig) allows to configure
 /// extraction process.
 ///
-/// ## Example
+/// # Examples
+/// ```
+/// use actix_web::{post, web, FromRequest};
 ///
-/// ```rust
-/// use actix_web::{web, App, FromRequest};
-///
-/// /// extract text data from request
+/// // extract text data from request
+/// #[post("/")]
 /// async fn index(text: String) -> String {
 ///     format!("Body {}!", text)
 /// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/index.html")
-///             .app_data(String::configure(|cfg| {  // <- limit size of the payload
-///                 cfg.limit(4096)
-///             }))
-///             .route(web::get().to(index))  // <- register handler with extractor params
-///     );
-/// }
-/// ```
 impl FromRequest for String {
     type Config = PayloadConfig;
     type Error = Error;
-    type Future = Either<
-        LocalBoxFuture<'static, Result<String, Error>>,
-        Ready<Result<String, Error>>,
-    >;
+    type Future = Either<StringExtractFut, Ready<Result<String, Error>>>;
 
     #[inline]
     fn from_request(req: &HttpRequest, payload: &mut dev::Payload) -> Self::Future {
         let cfg = PayloadConfig::from_req(req);
 
         // check content-type
-        if let Err(e) = cfg.check_mimetype(req) {
-            return Either::Right(err(e));
+        if let Err(err) = cfg.check_mimetype(req) {
+            return Either::Right(ready(Err(err)));
         }
 
         // check charset
         let encoding = match req.encoding() {
             Ok(enc) => enc,
-            Err(e) => return Either::Right(err(e.into())),
+            Err(err) => return Either::Right(ready(Err(err.into()))),
         };
         let limit = cfg.limit;
-        let fut = HttpMessageBody::new(req, payload).limit(limit);
+        let body_fut = HttpMessageBody::new(req, payload).limit(limit);
 
-        Either::Left(
-            async move {
-                let body = fut.await?;
-
-                if encoding == UTF_8 {
-                    Ok(str::from_utf8(body.as_ref())
-                        .map_err(|_| ErrorBadRequest("Can not decode body"))?
-                        .to_owned())
-                } else {
-                    Ok(encoding
-                        .decode_without_bom_handling_and_without_replacement(&body)
-                        .map(|s| s.into_owned())
-                        .ok_or_else(|| ErrorBadRequest("Can not decode body"))?)
-                }
-            }
-            .boxed_local(),
-        )
+        Either::Left(StringExtractFut { body_fut, encoding })
     }
 }
 
-/// Configuration for request's payload.
+pub struct StringExtractFut {
+    body_fut: HttpMessageBody,
+    encoding: &'static Encoding,
+}
+
+impl<'a> Future for StringExtractFut {
+    type Output = Result<String, Error>;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let encoding = self.encoding;
+
+        Pin::new(&mut self.body_fut).poll(cx).map(|out| {
+            let body = out?;
+            bytes_to_string(body, encoding)
+        })
+    }
+}
+
+fn bytes_to_string(body: Bytes, encoding: &'static Encoding) -> Result<String, Error> {
+    if encoding == UTF_8 {
+        Ok(str::from_utf8(body.as_ref())
+            .map_err(|_| ErrorBadRequest("Can not decode body"))?
+            .to_owned())
+    } else {
+        Ok(encoding
+            .decode_without_bom_handling_and_without_replacement(&body)
+            .map(|s| s.into_owned())
+            .ok_or_else(|| ErrorBadRequest("Can not decode body"))?)
+    }
+}
+
+/// Configuration for request payloads.
 ///
-/// Applies to the built-in `Bytes` and `String` extractors. Note that the Payload extractor does
+/// Applies to the built-in `Bytes` and `String` extractors. Note that the `Payload` extractor does
 /// not automatically check conformance with this configuration to allow more flexibility when
 /// building extractors on top of `Payload`.
+///
+/// By default, the payload size limit is 256kB and there is no mime type condition.
+///
+/// To use this, add an instance of it to your app or service through one of the
+/// `.app_data()` methods.
 #[derive(Clone)]
 pub struct PayloadConfig {
     limit: usize,
@@ -239,21 +198,21 @@ pub struct PayloadConfig {
 }
 
 impl PayloadConfig {
-    /// Create `PayloadConfig` instance and set max size of payload.
+    /// Create new instance with a size limit (in bytes) and no mime type condition.
     pub fn new(limit: usize) -> Self {
-        let mut cfg = Self::default();
-        cfg.limit = limit;
-        cfg
+        Self {
+            limit,
+            ..Default::default()
+        }
     }
 
-    /// Change max size of payload. By default max size is 256Kb
+    /// Set maximum accepted payload size in bytes. The default limit is 256kB.
     pub fn limit(mut self, limit: usize) -> Self {
         self.limit = limit;
         self
     }
 
-    /// Set required mime-type of the request. By default mime type is not
-    /// enforced.
+    /// Set required mime type of the request. By default mime type is not enforced.
     pub fn mimetype(mut self, mt: Mime) -> Self {
         self.mimetype = Some(mt);
         self
@@ -280,130 +239,117 @@ impl PayloadConfig {
     }
 
     /// Extract payload config from app data. Check both `T` and `Data<T>`, in that order, and fall
-    /// back to the default payload config.
+    /// back to the default payload config if neither is found.
     fn from_req(req: &HttpRequest) -> &Self {
         req.app_data::<Self>()
             .or_else(|| req.app_data::<web::Data<Self>>().map(|d| d.as_ref()))
-            .unwrap_or_else(|| &DEFAULT_CONFIG)
+            .unwrap_or(&DEFAULT_CONFIG)
     }
 }
 
-// Allow shared refs to default.
+/// Allow shared refs used as defaults.
 const DEFAULT_CONFIG: PayloadConfig = PayloadConfig {
-    limit: 262_144, // 2^18 bytes (~256kB)
+    limit: DEFAULT_CONFIG_LIMIT,
     mimetype: None,
 };
 
+const DEFAULT_CONFIG_LIMIT: usize = 262_144; // 2^18 bytes (~256kB)
+
 impl Default for PayloadConfig {
     fn default() -> Self {
         DEFAULT_CONFIG.clone()
     }
 }
 
-/// Future that resolves to a complete http message body.
+/// Future that resolves to a complete HTTP body payload.
 ///
-/// Load http message body.
-///
-/// By default only 256Kb payload reads to a memory, then
-/// `PayloadError::Overflow` get returned. Use `MessageBody::limit()`
-/// method to change upper limit.
+/// By default only 256kB payload is accepted before `PayloadError::Overflow` is returned.
+/// Use `MessageBody::limit()` method to change upper limit.
 pub struct HttpMessageBody {
     limit: usize,
     length: Option<usize>,
     #[cfg(feature = "compress")]
-    stream: Option<dev::Decompress<dev::Payload>>,
+    stream: dev::Decompress<dev::Payload>,
     #[cfg(not(feature = "compress"))]
-    stream: Option<dev::Payload>,
+    stream: dev::Payload,
+    buf: BytesMut,
     err: Option<PayloadError>,
-    fut: Option<LocalBoxFuture<'static, Result<Bytes, PayloadError>>>,
 }
 
 impl HttpMessageBody {
     /// Create `MessageBody` for request.
     #[allow(clippy::borrow_interior_mutable_const)]
     pub fn new(req: &HttpRequest, payload: &mut dev::Payload) -> HttpMessageBody {
-        let mut len = None;
+        let mut length = None;
+        let mut err = None;
+
         if let Some(l) = req.headers().get(&header::CONTENT_LENGTH) {
-            if let Ok(s) = l.to_str() {
-                if let Ok(l) = s.parse::<usize>() {
-                    len = Some(l)
-                } else {
-                    return Self::err(PayloadError::UnknownLength);
-                }
-            } else {
-                return Self::err(PayloadError::UnknownLength);
+            match l.to_str() {
+                Ok(s) => match s.parse::<usize>() {
+                    Ok(l) => {
+                        if l > DEFAULT_CONFIG_LIMIT {
+                            err = Some(PayloadError::Overflow);
+                        }
+                        length = Some(l)
+                    }
+                    Err(_) => err = Some(PayloadError::UnknownLength),
+                },
+                Err(_) => err = Some(PayloadError::UnknownLength),
             }
         }
 
         #[cfg(feature = "compress")]
-        let stream = Some(dev::Decompress::from_headers(payload.take(), req.headers()));
+        let stream = dev::Decompress::from_headers(payload.take(), req.headers());
         #[cfg(not(feature = "compress"))]
-        let stream = Some(payload.take());
+        let stream = payload.take();
 
         HttpMessageBody {
             stream,
-            limit: 262_144,
-            length: len,
-            fut: None,
-            err: None,
+            limit: DEFAULT_CONFIG_LIMIT,
+            length,
+            buf: BytesMut::with_capacity(8192),
+            err,
         }
     }
 
-    /// Change max size of payload. By default max size is 256Kb
+    /// Change max size of payload. By default max size is 256kB
     pub fn limit(mut self, limit: usize) -> Self {
+        if let Some(l) = self.length {
+            self.err = if l > limit {
+                Some(PayloadError::Overflow)
+            } else {
+                None
+            };
+        }
         self.limit = limit;
         self
     }
-
-    fn err(e: PayloadError) -> Self {
-        HttpMessageBody {
-            stream: None,
-            limit: 262_144,
-            fut: None,
-            err: Some(e),
-            length: None,
-        }
-    }
 }
 
 impl Future for HttpMessageBody {
     type Output = Result<Bytes, PayloadError>;
 
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        if let Some(ref mut fut) = self.fut {
-            return Pin::new(fut).poll(cx);
-        }
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.get_mut();
 
-        if let Some(err) = self.err.take() {
+        if let Some(err) = this.err.take() {
             return Poll::Ready(Err(err));
         }
 
-        if let Some(len) = self.length.take() {
-            if len > self.limit {
-                return Poll::Ready(Err(PayloadError::Overflow));
-            }
-        }
-
-        // future
-        let limit = self.limit;
-        let mut stream = self.stream.take().unwrap();
-        self.fut = Some(
-            async move {
-                let mut body = BytesMut::with_capacity(8192);
-
-                while let Some(item) = stream.next().await {
-                    let chunk = item?;
-                    if body.len() + chunk.len() > limit {
-                        return Err(PayloadError::Overflow);
+        loop {
+            let res = ready!(Pin::new(&mut this.stream).poll_next(cx));
+            match res {
+                Some(chunk) => {
+                    let chunk = chunk?;
+                    if this.buf.len() + chunk.len() > this.limit {
+                        return Poll::Ready(Err(PayloadError::Overflow));
                     } else {
-                        body.extend_from_slice(&chunk);
+                        this.buf.extend_from_slice(&chunk);
                     }
                 }
-                Ok(body.freeze())
+                None => return Poll::Ready(Ok(this.buf.split().freeze())),
             }
-            .boxed_local(),
-        );
-        self.poll(cx)
+        }
     }
 }
 
@@ -422,14 +368,13 @@ mod tests {
         let cfg = PayloadConfig::default().mimetype(mime::APPLICATION_JSON);
         assert!(cfg.check_mimetype(&req).is_err());
 
-        let req = TestRequest::with_header(
-            header::CONTENT_TYPE,
-            "application/x-www-form-urlencoded",
-        )
-        .to_http_request();
+        let req = TestRequest::default()
+            .insert_header((header::CONTENT_TYPE, "application/x-www-form-urlencoded"))
+            .to_http_request();
         assert!(cfg.check_mimetype(&req).is_err());
 
-        let req = TestRequest::with_header(header::CONTENT_TYPE, "application/json")
+        let req = TestRequest::default()
+            .insert_header((header::CONTENT_TYPE, "application/json"))
             .to_http_request();
         assert!(cfg.check_mimetype(&req).is_ok());
     }
@@ -444,13 +389,11 @@ mod tests {
             "payload is probably json string"
         }
 
-        let mut srv = init_service(
+        let srv = init_service(
             App::new()
                 .service(
                     web::resource("/bytes-app-data")
-                        .app_data(
-                            PayloadConfig::default().mimetype(mime::APPLICATION_JSON),
-                        )
+                        .app_data(PayloadConfig::default().mimetype(mime::APPLICATION_JSON))
                         .route(web::get().to(bytes_handler)),
                 )
                 .service(
@@ -460,9 +403,7 @@ mod tests {
                 )
                 .service(
                     web::resource("/string-app-data")
-                        .app_data(
-                            PayloadConfig::default().mimetype(mime::APPLICATION_JSON),
-                        )
+                        .app_data(PayloadConfig::default().mimetype(mime::APPLICATION_JSON))
                         .route(web::get().to(string_handler)),
                 )
                 .service(
@@ -474,49 +415,50 @@ mod tests {
         .await;
 
         let req = TestRequest::with_uri("/bytes-app-data").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
 
         let req = TestRequest::with_uri("/bytes-data").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
 
         let req = TestRequest::with_uri("/string-app-data").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
 
         let req = TestRequest::with_uri("/string-data").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
 
         let req = TestRequest::with_uri("/bytes-app-data")
-            .header(header::CONTENT_TYPE, mime::APPLICATION_JSON)
+            .insert_header(header::ContentType(mime::APPLICATION_JSON))
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
         let req = TestRequest::with_uri("/bytes-data")
-            .header(header::CONTENT_TYPE, mime::APPLICATION_JSON)
+            .insert_header(header::ContentType(mime::APPLICATION_JSON))
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
         let req = TestRequest::with_uri("/string-app-data")
-            .header(header::CONTENT_TYPE, mime::APPLICATION_JSON)
+            .insert_header(header::ContentType(mime::APPLICATION_JSON))
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
 
         let req = TestRequest::with_uri("/string-data")
-            .header(header::CONTENT_TYPE, mime::APPLICATION_JSON)
+            .insert_header(header::ContentType(mime::APPLICATION_JSON))
             .to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
         assert_eq!(resp.status(), StatusCode::OK);
     }
 
     #[actix_rt::test]
     async fn test_bytes() {
-        let (req, mut pl) = TestRequest::with_header(header::CONTENT_LENGTH, "11")
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((header::CONTENT_LENGTH, "11"))
             .set_payload(Bytes::from_static(b"hello=world"))
             .to_http_parts();
 
@@ -526,7 +468,8 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_string() {
-        let (req, mut pl) = TestRequest::with_header(header::CONTENT_LENGTH, "11")
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((header::CONTENT_LENGTH, "11"))
             .set_payload(Bytes::from_static(b"hello=world"))
             .to_http_parts();
 
@@ -536,21 +479,23 @@ mod tests {
 
     #[actix_rt::test]
     async fn test_message_body() {
-        let (req, mut pl) = TestRequest::with_header(header::CONTENT_LENGTH, "xxxx")
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((header::CONTENT_LENGTH, "xxxx"))
             .to_srv_request()
             .into_parts();
         let res = HttpMessageBody::new(&req, &mut pl).await;
         match res.err().unwrap() {
-            PayloadError::UnknownLength => (),
+            PayloadError::UnknownLength => {}
             _ => unreachable!("error"),
         }
 
-        let (req, mut pl) = TestRequest::with_header(header::CONTENT_LENGTH, "1000000")
+        let (req, mut pl) = TestRequest::default()
+            .insert_header((header::CONTENT_LENGTH, "1000000"))
             .to_srv_request()
             .into_parts();
         let res = HttpMessageBody::new(&req, &mut pl).await;
         match res.err().unwrap() {
-            PayloadError::Overflow => (),
+            PayloadError::Overflow => {}
             _ => unreachable!("error"),
         }
 
@@ -565,7 +510,7 @@ mod tests {
             .to_http_parts();
         let res = HttpMessageBody::new(&req, &mut pl).limit(5).await;
         match res.err().unwrap() {
-            PayloadError::Overflow => (),
+            PayloadError::Overflow => {}
             _ => unreachable!("error"),
         }
     }
diff --git a/src/types/query.rs b/src/types/query.rs
index f9440e1b4..691a4792b 100644
--- a/src/types/query.rs
+++ b/src/types/query.rs
@@ -1,30 +1,27 @@
-//! Query extractor
+//! For query parameter extractor documentation, see [`Query`].
 
-use std::sync::Arc;
-use std::{fmt, ops};
+use std::{fmt, ops, sync::Arc};
 
-use actix_http::error::Error;
 use futures_util::future::{err, ok, Ready};
 use serde::de;
 
-use crate::dev::Payload;
-use crate::error::QueryPayloadError;
-use crate::extract::FromRequest;
-use crate::request::HttpRequest;
+use crate::{dev::Payload, error::QueryPayloadError, Error, FromRequest, HttpRequest};
 
 /// Extract typed information from the request's query.
 ///
-/// **Note**: A query string consists of unordered `key=value` pairs, therefore it cannot
-/// be decoded into any type which depends upon data ordering e.g. tuples or tuple-structs.
-/// Attempts to do so will *fail at runtime*.
+/// To extract typed data from the URL query string, the inner type `T` must implement the
+/// [`serde::Deserialize`] trait.
 ///
-/// [**QueryConfig**](struct.QueryConfig.html) allows to configure extraction process.
+/// Use [`QueryConfig`] to configure extraction process.
 ///
-/// ## Example
+/// # Panics
+/// A query string consists of unordered `key=value` pairs, therefore it cannot be decoded into any
+/// type which depends upon data ordering (eg. tuples). Trying to do so will result in a panic.
 ///
-/// ```rust
-/// use actix_web::{web, App};
-/// use serde_derive::Deserialize;
+/// # Examples
+/// ```
+/// use actix_web::{get, web};
+/// use serde::Deserialize;
 ///
 /// #[derive(Debug, Deserialize)]
 /// pub enum ResponseType {
@@ -38,35 +35,40 @@ use crate::request::HttpRequest;
 ///    response_type: ResponseType,
 /// }
 ///
-/// // Use `Query` extractor for query information (and destructure it within the signature).
-/// // This handler gets called only if the request's query string contains a `username` field.
-/// // The correct request for this handler would be `/index.html?id=64&response_type=Code"`.
-/// async fn index(web::Query(info): web::Query<AuthRequest>) -> String {
-///     format!("Authorization request for client with id={} and type={:?}!", info.id, info.response_type)
-/// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///        web::resource("/index.html").route(web::get().to(index))); // <- use `Query` extractor
+/// // Deserialize `AuthRequest` struct from query string.
+/// // This handler gets called only if the request's query parameters contain both fields.
+/// // A valid request path for this handler would be `/?id=64&response_type=Code"`.
+/// #[get("/")]
+/// async fn index(info: web::Query<AuthRequest>) -> String {
+///     format!("Authorization request for id={} and type={:?}!", info.id, info.response_type)
 /// }
 /// ```
-#[derive(PartialEq, Eq, PartialOrd, Ord)]
-pub struct Query<T>(pub T);
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Query<T>(T);
 
 impl<T> Query<T> {
-    /// Deconstruct to a inner value
+    /// Unwrap into inner `T` value.
     pub fn into_inner(self) -> T {
         self.0
     }
 
-    /// Get query parameters from the path
+    /// Deserialize `T` from a URL encoded query parameter string.
+    ///
+    /// ```
+    /// # use std::collections::HashMap;
+    /// # use actix_web::web::Query;
+    /// let numbers = Query::<HashMap<String, u32>>::from_query("one=1&two=2").unwrap();
+    /// assert_eq!(numbers.get("one"), Some(&1));
+    /// assert_eq!(numbers.get("two"), Some(&2));
+    /// assert!(numbers.get("three").is_none());
+    /// ```
     pub fn from_query(query_str: &str) -> Result<Self, QueryPayloadError>
     where
         T: de::DeserializeOwned,
     {
         serde_urlencoded::from_str::<T>(query_str)
-            .map(|val| Ok(Query(val)))
-            .unwrap_or_else(move |e| Err(QueryPayloadError::Deserialize(e)))
+            .map(Self)
+            .map_err(QueryPayloadError::Deserialize)
     }
 }
 
@@ -96,39 +98,7 @@ impl<T: fmt::Display> fmt::Display for Query<T> {
     }
 }
 
-/// Extract typed information from the request's query.
-///
-/// ## Example
-///
-/// ```rust
-/// use actix_web::{web, App};
-/// use serde_derive::Deserialize;
-///
-/// #[derive(Debug, Deserialize)]
-/// pub enum ResponseType {
-///    Token,
-///    Code
-/// }
-///
-/// #[derive(Deserialize)]
-/// pub struct AuthRequest {
-///    id: u64,
-///    response_type: ResponseType,
-/// }
-///
-/// // Use `Query` extractor for query information.
-/// // This handler get called only if request's query contains `username` field
-/// // The correct request for this handler would be `/index.html?id=64&response_type=Code"`
-/// async fn index(info: web::Query<AuthRequest>) -> String {
-///     format!("Authorization request for client with id={} and type={:?}!", info.id, info.response_type)
-/// }
-///
-/// fn main() {
-///     let app = App::new().service(
-///        web::resource("/index.html")
-///            .route(web::get().to(index))); // <- use `Query` extractor
-/// }
-/// ```
+/// See [here](#usage) for example of usage as an extractor.
 impl<T> FromRequest for Query<T>
 where
     T: de::DeserializeOwned,
@@ -141,7 +111,7 @@ where
     fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
         let error_handler = req
             .app_data::<Self::Config>()
-            .map(|c| c.ehandler.clone())
+            .map(|c| c.err_handler.clone())
             .unwrap_or(None);
 
         serde_urlencoded::from_str::<T>(req.query_string())
@@ -166,13 +136,12 @@ where
     }
 }
 
-/// Query extractor configuration
+/// Query extractor configuration.
 ///
-/// ## Example
-///
-/// ```rust
-/// use actix_web::{error, web, App, FromRequest, HttpResponse};
-/// use serde_derive::Deserialize;
+/// # Examples
+/// ```
+/// use actix_web::{error, get, web, App, FromRequest, HttpResponse};
+/// use serde::Deserialize;
 ///
 /// #[derive(Deserialize)]
 /// struct Info {
@@ -180,28 +149,25 @@ where
 /// }
 ///
 /// /// deserialize `Info` from request's querystring
+/// #[get("/")]
 /// async fn index(info: web::Query<Info>) -> String {
 ///     format!("Welcome {}!", info.username)
 /// }
 ///
-/// fn main() {
-///     let app = App::new().service(
-///         web::resource("/index.html").app_data(
-///             // change query extractor configuration
-///             web::QueryConfig::default()
-///                 .error_handler(|err, req| {  // <- create custom error response
-///                     error::InternalError::from_response(
-///                         err, HttpResponse::Conflict().finish()).into()
-///                 })
-///             )
-///             .route(web::post().to(index))
-///     );
-/// }
+/// // custom `Query` extractor configuration
+/// let query_cfg = web::QueryConfig::default()
+///     // use custom error handler
+///     .error_handler(|err, req| {
+///         error::InternalError::from_response(err, HttpResponse::Conflict().finish()).into()
+///     });
+///
+/// App::new()
+///     .app_data(query_cfg)
+///     .service(index);
 /// ```
 #[derive(Clone)]
 pub struct QueryConfig {
-    ehandler:
-        Option<Arc<dyn Fn(QueryPayloadError, &HttpRequest) -> Error + Send + Sync>>,
+    err_handler: Option<Arc<dyn Fn(QueryPayloadError, &HttpRequest) -> Error + Send + Sync>>,
 }
 
 impl QueryConfig {
@@ -210,14 +176,14 @@ impl QueryConfig {
     where
         F: Fn(QueryPayloadError, &HttpRequest) -> Error + Send + Sync + 'static,
     {
-        self.ehandler = Some(Arc::new(f));
+        self.err_handler = Some(Arc::new(f));
         self
     }
 }
 
 impl Default for QueryConfig {
     fn default() -> Self {
-        QueryConfig { ehandler: None }
+        QueryConfig { err_handler: None }
     }
 }
 
@@ -225,7 +191,7 @@ impl Default for QueryConfig {
 mod tests {
     use actix_http::http::StatusCode;
     use derive_more::Display;
-    use serde_derive::Deserialize;
+    use serde::Deserialize;
 
     use super::*;
     use crate::error::InternalError;
@@ -271,6 +237,17 @@ mod tests {
         assert_eq!(s.id, "test1");
     }
 
+    #[actix_rt::test]
+    #[should_panic]
+    async fn test_tuple_panic() {
+        let req = TestRequest::with_uri("/?one=1&two=2").to_srv_request();
+        let (req, mut pl) = req.into_parts();
+
+        Query::<(u32, u32)>::from_request(&req, &mut pl)
+            .await
+            .unwrap();
+    }
+
     #[actix_rt::test]
     async fn test_custom_error_responder() {
         let req = TestRequest::with_uri("/name/user1/")
diff --git a/src/types/readlines.rs b/src/types/readlines.rs
index f03235377..b8bdcc504 100644
--- a/src/types/readlines.rs
+++ b/src/types/readlines.rs
@@ -1,17 +1,23 @@
-use std::borrow::Cow;
-use std::pin::Pin;
-use std::str;
-use std::task::{Context, Poll};
+//! For request line reader documentation, see [`Readlines`].
+
+use std::{
+    borrow::Cow,
+    pin::Pin,
+    str,
+    task::{Context, Poll},
+};
 
 use bytes::{Bytes, BytesMut};
 use encoding_rs::{Encoding, UTF_8};
-use futures_util::stream::Stream;
+use futures_core::{ready, stream::Stream};
 
-use crate::dev::Payload;
-use crate::error::{PayloadError, ReadlinesError};
-use crate::HttpMessage;
+use crate::{
+    dev::Payload,
+    error::{PayloadError, ReadlinesError},
+    HttpMessage,
+};
 
-/// Stream to read request line by line.
+/// Stream that reads request line by line.
 pub struct Readlines<T: HttpMessage> {
     stream: Payload<T::Stream>,
     buff: BytesMut,
@@ -43,7 +49,7 @@ where
         }
     }
 
-    /// Change max line size. By default max size is 256Kb
+    /// Set maximum accepted payload size. The default limit is 256kB.
     pub fn limit(mut self, limit: usize) -> Self {
         self.limit = limit;
         self
@@ -68,10 +74,7 @@ where
 {
     type Item = Result<String, ReadlinesError>;
 
-    fn poll_next(
-        self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         let this = self.get_mut();
 
         if let Some(err) = this.err.take() {
@@ -108,9 +111,10 @@ where
             }
             this.checked_buff = true;
         }
+
         // poll req for more bytes
-        match Pin::new(&mut this.stream).poll_next(cx) {
-            Poll::Ready(Some(Ok(mut bytes))) => {
+        match ready!(Pin::new(&mut this.stream).poll_next(cx)) {
+            Some(Ok(mut bytes)) => {
                 // check if there is a newline in bytes
                 let mut found: Option<usize> = None;
                 for (ind, b) in bytes.iter().enumerate() {
@@ -144,8 +148,8 @@ where
                 this.buff.extend_from_slice(&bytes);
                 Poll::Pending
             }
-            Poll::Pending => Poll::Pending,
-            Poll::Ready(None) => {
+
+            None => {
                 if this.buff.is_empty() {
                     return Poll::Ready(None);
                 }
@@ -165,7 +169,8 @@ where
                 this.buff.clear();
                 Poll::Ready(Some(Ok(line)))
             }
-            Poll::Ready(Some(Err(e))) => Poll::Ready(Some(Err(ReadlinesError::from(e)))),
+
+            Some(Err(err)) => Poll::Ready(Some(Err(ReadlinesError::from(err)))),
         }
     }
 }
diff --git a/src/web.rs b/src/web.rs
index 1d1174f41..1cef37109 100644
--- a/src/web.rs
+++ b/src/web.rs
@@ -1,15 +1,15 @@
 //! Essentials helper functions and types for application registration.
+
 use actix_http::http::Method;
 use actix_router::IntoPattern;
 use std::future::Future;
 
 pub use actix_http::Response as HttpResponse;
-pub use bytes::{Bytes, BytesMut};
-pub use futures_channel::oneshot::Canceled;
+pub use bytes::{Buf, BufMut, Bytes, BytesMut};
 
 use crate::error::BlockingError;
 use crate::extract::FromRequest;
-use crate::handler::Factory;
+use crate::handler::Handler;
 use crate::resource::Resource;
 use crate::responder::Responder;
 use crate::route::Route;
@@ -19,6 +19,7 @@ use crate::service::WebService;
 pub use crate::config::ServiceConfig;
 pub use crate::data::Data;
 pub use crate::request::HttpRequest;
+pub use crate::request_data::ReqData;
 pub use crate::types::*;
 
 /// Create resource for a specific path.
@@ -243,12 +244,12 @@ pub fn method(method: Method) -> Route {
 ///         web::to(index))
 /// );
 /// ```
-pub fn to<F, I, R, U>(handler: F) -> Route
+pub fn to<F, I, R>(handler: F) -> Route
 where
-    F: Factory<I, R, U>,
+    F: Handler<I, R>,
     I: FromRequest + 'static,
-    R: Future<Output = U> + 'static,
-    U: Responder + 'static,
+    R: Future + 'static,
+    R::Output: Responder + 'static,
 {
     Route::new().to(handler)
 }
@@ -274,11 +275,11 @@ pub fn service<T: IntoPattern>(path: T) -> WebService {
 
 /// Execute blocking function on a thread pool, returns future that resolves
 /// to result of the function execution.
-pub async fn block<F, I, E>(f: F) -> Result<I, BlockingError<E>>
+pub fn block<F, R>(f: F) -> impl Future<Output = Result<R, BlockingError>>
 where
-    F: FnOnce() -> Result<I, E> + Send + 'static,
-    I: Send + 'static,
-    E: Send + std::fmt::Debug + 'static,
+    F: FnOnce() -> R + Send + 'static,
+    R: Send + 'static,
 {
-    actix_threadpool::run(f).await
+    let fut = actix_rt::task::spawn_blocking(f);
+    async { fut.await.map_err(|_| BlockingError) }
 }
diff --git a/test-server/Cargo.toml b/test-server/Cargo.toml
deleted file mode 100644
index d06bd5dec..000000000
--- a/test-server/Cargo.toml
+++ /dev/null
@@ -1,56 +0,0 @@
-[package]
-name = "actix-http-test"
-version = "2.0.0"
-authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
-description = "Actix HTTP test server"
-readme = "README.md"
-keywords = ["http", "web", "framework", "async", "futures"]
-homepage = "https://actix.rs"
-repository = "https://github.com/actix/actix-web.git"
-documentation = "https://docs.rs/actix-http-test/"
-categories = ["network-programming", "asynchronous",
-              "web-programming::http-server",
-              "web-programming::websocket"]
-license = "MIT OR Apache-2.0"
-exclude = [".gitignore", ".cargo/config"]
-edition = "2018"
-
-[package.metadata.docs.rs]
-features = []
-
-[lib]
-name = "actix_http_test"
-path = "src/lib.rs"
-
-[features]
-default = []
-
-# openssl
-openssl = ["open-ssl", "awc/openssl"]
-
-[dependencies]
-actix-service = "1.0.6"
-actix-codec = "0.3.0"
-actix-connect = "2.0.0"
-actix-utils = "2.0.0"
-actix-rt = "1.1.1"
-actix-server = "1.0.0"
-actix-testing = "1.0.0"
-awc = "2.0.0"
-
-base64 = "0.12"
-bytes = "0.5.3"
-futures-core = { version = "0.3.5", default-features = false }
-http = "0.2.0"
-log = "0.4"
-socket2 = "0.3"
-serde = "1.0"
-serde_json = "1.0"
-slab = "0.4"
-serde_urlencoded = "0.6.1"
-time = { version = "0.2.7", default-features = false, features = ["std"] }
-open-ssl = { version = "0.10", package = "openssl", optional = true }
-
-[dev-dependencies]
-actix-web = "3.0.0"
-actix-http = "2.0.0"
diff --git a/test-server/README.md b/test-server/README.md
deleted file mode 100644
index db0791db7..000000000
--- a/test-server/README.md
+++ /dev/null
@@ -1,9 +0,0 @@
-# Actix http test server [![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web) [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) [![crates.io](https://meritbadge.herokuapp.com/actix-http-test)](https://crates.io/crates/actix-http-test) [![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-
-## Documentation & community resources
-
-* [User Guide](https://actix.rs/docs/)
-* [API Documentation](https://docs.rs/actix-http-test/)
-* [Chat on gitter](https://gitter.im/actix/actix)
-* Cargo package: [actix-http-test](https://crates.io/crates/actix-http-test)
-* Minimum supported Rust version: 1.40 or later
diff --git a/tests/cert.pem b/tests/cert.pem
deleted file mode 100644
index 0eeb6721d..000000000
--- a/tests/cert.pem
+++ /dev/null
@@ -1,19 +0,0 @@
------BEGIN CERTIFICATE-----
-MIIDEDCCAfgCCQCQdmIZc/Ib/jANBgkqhkiG9w0BAQsFADBKMQswCQYDVQQGEwJ1
-czELMAkGA1UECAwCY2ExCzAJBgNVBAcMAnNmMSEwHwYJKoZIhvcNAQkBFhJmYWZo
-cmQ5MUBnbWFpbC5jb20wHhcNMTkxMTE5MTEwNjU1WhcNMjkxMTE2MTEwNjU1WjBK
-MQswCQYDVQQGEwJ1czELMAkGA1UECAwCY2ExCzAJBgNVBAcMAnNmMSEwHwYJKoZI
-hvcNAQkBFhJmYWZocmQ5MUBnbWFpbC5jb20wggEiMA0GCSqGSIb3DQEBAQUAA4IB
-DwAwggEKAoIBAQDcnaz12CKzUL7248V7Axhms/O9UQXfAdw0yolEfC3P5jADa/1C
-+kLWKjAc2coqDSbGsrsR6KiH2g06Kunx+tSGqUO+Sct7HEehmxndiSwx/hfMWezy
-XRe/olcHFTeCk/Tllz4xGEplhPua6GLhJygLOhAMiV8cwCYrgyPqsDduExLDFCqc
-K2xntIPreumXpiE3QY4+MWyteiJko4IWDFf/UwwsdCY5MlFfw1F/Uv9vz7FfOfvu
-GccHd/ex8cOwotUqd6emZb+0bVE24Sv8U+yLnHIVx/tOkxgMAnJEpAnf2G3Wp3zU
-b2GJosbmfGaf+xTfnGGhTLLL7kCtva+NvZr5AgMBAAEwDQYJKoZIhvcNAQELBQAD
-ggEBANftoL8zDGrjCwWvct8kOOqset2ukK8vjIGwfm88CKsy0IfSochNz2qeIu9R
-ZuO7c0pfjmRkir9ZQdq9vXgG3ccL9UstFsferPH9W3YJ83kgXg3fa0EmCiN/0hwz
-6Ij1ZBiN1j3+d6+PJPgyYFNu2nGwox5mJ9+aRAGe0/9c63PEOY8P2TI4HsiPmYSl
-fFR8k/03vr6e+rTKW85BgctjvYKe/TnFxeCQ7dZ+na7vlEtch4tNmy6O/vEk2kCt
-5jW0DUxhmRsv2wGmfFRI0+LotHjoXQQZi6nN5aGL3odaGF3gYwIVlZNd3AdkwDQz
-BzG0ZwXuDDV9bSs3MfWEWcy4xuU=
------END CERTIFICATE-----
diff --git a/tests/key.pem b/tests/key.pem
deleted file mode 100644
index a6d308168..000000000
--- a/tests/key.pem
+++ /dev/null
@@ -1,28 +0,0 @@
------BEGIN PRIVATE KEY-----
-MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQDcnaz12CKzUL72
-48V7Axhms/O9UQXfAdw0yolEfC3P5jADa/1C+kLWKjAc2coqDSbGsrsR6KiH2g06
-Kunx+tSGqUO+Sct7HEehmxndiSwx/hfMWezyXRe/olcHFTeCk/Tllz4xGEplhPua
-6GLhJygLOhAMiV8cwCYrgyPqsDduExLDFCqcK2xntIPreumXpiE3QY4+MWyteiJk
-o4IWDFf/UwwsdCY5MlFfw1F/Uv9vz7FfOfvuGccHd/ex8cOwotUqd6emZb+0bVE2
-4Sv8U+yLnHIVx/tOkxgMAnJEpAnf2G3Wp3zUb2GJosbmfGaf+xTfnGGhTLLL7kCt
-va+NvZr5AgMBAAECggEBAKoU0UwzVgVCQgca8Jt2dnBvWYDhnxIfYAI/BvaKedMm
-1ms87OKfB7oOiksjyI0E2JklH72dzZf2jm4CuZt5UjGC+xwPzlTaJ4s6hQVbBHyC
-NRyxU1BCXtW5tThbrhD4OjxqjmLRJEIB9OunLtwAEQoeuFLB8Va7+HFhR+Zd9k3f
-7aVA93pC5A50NRbZlke4miJ3Q8n7ZF0+UmxkBfm3fbqLk7aMWkoEKwLLTadjRlu1
-bBp0YDStX66I/p1kujqBOdh6VpPvxFOa1sV9pq0jeiGc9YfSkzRSKzIn8GoyviFB
-fHeszQdNlcnrSDSNnMABAw+ZpxUO7SCaftjwejEmKZUCgYEA+TY43VpmV95eY7eo
-WKwGepiHE0fwQLuKGELmZdZI80tFi73oZMuiB5WzwmkaKGcJmm7KGE9KEvHQCo9j
-xvmktBR0VEZH8pmVfun+4h6+0H7m/NKMBBeOyv/IK8jBgHjkkB6e6nmeR7CqTxCw
-tf9tbajl1QN8gNzXZSjBDT/lanMCgYEA4qANOKOSiEARtgwyXQeeSJcM2uPv6zF3
-ffM7vjSedtuEOHUSVeyBP/W8KDt7zyPppO/WNbURHS+HV0maS9yyj6zpVS2HGmbs
-3fetswsQ+zYVdokW89x4oc2z4XOGHd1LcSlyhRwPt0u2g1E9L0irwTQLWU0npFmG
-PRf7sN9+LeMCgYAGkDUDL2ROoB6gRa/7Vdx90hKMoXJkYgwLA4gJ2pDlR3A3c/Lw
-5KQJyxmG3zm/IqeQF6be6QesZA30mT4peV2rGHbP2WH/s6fKReNelSy1VQJEWk8x
-tGUgV4gwDwN5nLV4TjYlOrq+bJqvpmLhCC8bmj0jVQosYqSRl3cuICasnQKBgGlV
-VO/Xb1su1EyWPK5qxRIeSxZOTYw2sMB01nbgxCqge0M2fvA6/hQ5ZlwY0cIEgits
-YlcSMsMq/TAAANxz1vbaupUhlSMbZcsBvNV0Nk9c4vr2Wxm7hsJF9u66IEMvQUp2
-pkjiMxfR9CHzF4orr9EcHI5EQ0Grbq5kwFKEfoRbAoGAcWoFPILeJOlp2yW/Ds3E
-g2fQdI9BAamtEZEaslJmZMmsDTg5ACPcDkOSFEQIaJ7wLPXeZy74FVk/NrY5F8Gz
-bjX9OD/xzwp852yW5L9r62vYJakAlXef5jI6CFdYKDDCcarU0S7W5k6kq9n+wrBR
-i1NklYmUAMr2q59uJA5zsic=
------END PRIVATE KEY-----
diff --git a/tests/test_httpserver.rs b/tests/test_httpserver.rs
index 118640aca..043159376 100644
--- a/tests/test_httpserver.rs
+++ b/tests/test_httpserver.rs
@@ -2,7 +2,12 @@ use std::sync::mpsc;
 use std::{thread, time::Duration};
 
 #[cfg(feature = "openssl")]
-use open_ssl::ssl::SslAcceptorBuilder;
+extern crate tls_openssl as openssl;
+#[cfg(feature = "rustls")]
+extern crate tls_rustls as rustls;
+
+#[cfg(feature = "openssl")]
+use openssl::ssl::SslAcceptorBuilder;
 
 use actix_web::{test, web, App, HttpResponse, HttpServer};
 
@@ -13,28 +18,31 @@ async fn test_start() {
     let (tx, rx) = mpsc::channel();
 
     thread::spawn(move || {
-        let sys = actix_rt::System::new("test");
+        let sys = actix_rt::System::new();
 
-        let srv = HttpServer::new(|| {
-            App::new().service(
-                web::resource("/").route(web::to(|| HttpResponse::Ok().body("test"))),
-            )
-        })
-        .workers(1)
-        .backlog(1)
-        .max_connections(10)
-        .max_connection_rate(10)
-        .keep_alive(10)
-        .client_timeout(5000)
-        .client_shutdown(0)
-        .server_hostname("localhost")
-        .system_exit()
-        .disable_signals()
-        .bind(format!("{}", addr))
-        .unwrap()
-        .run();
+        sys.block_on(async {
+            let srv = HttpServer::new(|| {
+                App::new().service(
+                    web::resource("/").route(web::to(|| HttpResponse::Ok().body("test"))),
+                )
+            })
+            .workers(1)
+            .backlog(1)
+            .max_connections(10)
+            .max_connection_rate(10)
+            .keep_alive(10)
+            .client_timeout(5000)
+            .client_shutdown(0)
+            .server_hostname("localhost")
+            .system_exit()
+            .disable_signals()
+            .bind(format!("{}", addr))
+            .unwrap()
+            .run();
+
+            let _ = tx.send((srv, actix_rt::System::current()));
+        });
 
-        let _ = tx.send((srv, actix_rt::System::current()));
         let _ = sys.run();
     });
     let (srv, sys) = rx.recv().unwrap();
@@ -65,15 +73,22 @@ async fn test_start() {
 
 #[cfg(feature = "openssl")]
 fn ssl_acceptor() -> std::io::Result<SslAcceptorBuilder> {
-    use open_ssl::ssl::{SslAcceptor, SslFiletype, SslMethod};
-    // load ssl keys
+    use openssl::{
+        pkey::PKey,
+        ssl::{SslAcceptor, SslMethod},
+        x509::X509,
+    };
+
+    let cert = rcgen::generate_simple_self_signed(vec!["localhost".to_owned()]).unwrap();
+    let cert_file = cert.serialize_pem().unwrap();
+    let key_file = cert.serialize_private_key_pem();
+    let cert = X509::from_pem(cert_file.as_bytes()).unwrap();
+    let key = PKey::private_key_from_pem(key_file.as_bytes()).unwrap();
+
     let mut builder = SslAcceptor::mozilla_intermediate(SslMethod::tls()).unwrap();
-    builder
-        .set_private_key_file("tests/key.pem", SslFiletype::PEM)
-        .unwrap();
-    builder
-        .set_certificate_chain_file("tests/cert.pem")
-        .unwrap();
+    builder.set_certificate(&cert).unwrap();
+    builder.set_private_key(&key).unwrap();
+
     Ok(builder)
 }
 
@@ -86,7 +101,7 @@ async fn test_start_ssl() {
     let (tx, rx) = mpsc::channel();
 
     thread::spawn(move || {
-        let sys = actix_rt::System::new("test");
+        let sys = actix_rt::System::new();
         let builder = ssl_acceptor().unwrap();
 
         let srv = HttpServer::new(|| {
@@ -100,15 +115,18 @@ async fn test_start_ssl() {
         .system_exit()
         .disable_signals()
         .bind_openssl(format!("{}", addr), builder)
-        .unwrap()
-        .run();
+        .unwrap();
+
+        sys.block_on(async {
+            let srv = srv.run();
+            let _ = tx.send((srv, actix_rt::System::current()));
+        });
 
-        let _ = tx.send((srv, actix_rt::System::current()));
         let _ = sys.run();
     });
     let (srv, sys) = rx.recv().unwrap();
 
-    use open_ssl::ssl::{SslConnector, SslMethod, SslVerifyMode};
+    use openssl::ssl::{SslConnector, SslMethod, SslVerifyMode};
     let mut builder = SslConnector::builder(SslMethod::tls()).unwrap();
     builder.set_verify(SslVerifyMode::NONE);
     let _ = builder
@@ -119,8 +137,7 @@ async fn test_start_ssl() {
         .connector(
             awc::Connector::new()
                 .ssl(builder.build())
-                .timeout(Duration::from_millis(100))
-                .finish(),
+                .timeout(Duration::from_millis(100)),
         )
         .finish();
 
diff --git a/tests/test_server.rs b/tests/test_server.rs
index f8a9ab86d..2466730f9 100644
--- a/tests/test_server.rs
+++ b/tests/test_server.rs
@@ -1,23 +1,35 @@
-use std::future::Future;
-use std::io::{Read, Write};
-use std::pin::Pin;
-use std::task::{Context, Poll};
+#[cfg(feature = "openssl")]
+extern crate tls_openssl as openssl;
+#[cfg(feature = "rustls")]
+extern crate tls_rustls as rustls;
+
+use std::{
+    future::Future,
+    io::{Read, Write},
+    pin::Pin,
+    task::{Context, Poll},
+};
 
 use actix_http::http::header::{
-    ContentEncoding, ACCEPT_ENCODING, CONTENT_ENCODING, CONTENT_LENGTH,
-    TRANSFER_ENCODING,
+    ContentEncoding, ACCEPT_ENCODING, CONTENT_ENCODING, CONTENT_LENGTH, TRANSFER_ENCODING,
 };
 use brotli2::write::{BrotliDecoder, BrotliEncoder};
 use bytes::Bytes;
-use flate2::read::GzDecoder;
-use flate2::write::{GzEncoder, ZlibDecoder, ZlibEncoder};
-use flate2::Compression;
+use flate2::{
+    read::GzDecoder,
+    write::{GzEncoder, ZlibDecoder, ZlibEncoder},
+    Compression,
+};
 use futures_util::ready;
+use openssl::{
+    pkey::PKey,
+    ssl::{SslAcceptor, SslMethod},
+    x509::X509,
+};
 use rand::{distributions::Alphanumeric, Rng};
 
 use actix_web::dev::BodyEncoding;
-use actix_web::middleware::normalize::TrailingSlash;
-use actix_web::middleware::{Compress, NormalizePath};
+use actix_web::middleware::{Compress, NormalizePath, TrailingSlash};
 use actix_web::{dev, test, web, App, Error, HttpResponse};
 
 const STR: &str = "Hello World Hello World Hello World Hello World Hello World \
@@ -42,10 +54,34 @@ const STR: &str = "Hello World Hello World Hello World Hello World Hello World \
                    Hello World Hello World Hello World Hello World Hello World \
                    Hello World Hello World Hello World Hello World Hello World";
 
+fn openssl_config() -> SslAcceptor {
+    let cert = rcgen::generate_simple_self_signed(vec!["localhost".to_owned()]).unwrap();
+    let cert_file = cert.serialize_pem().unwrap();
+    let key_file = cert.serialize_private_key_pem();
+    let cert = X509::from_pem(cert_file.as_bytes()).unwrap();
+    let key = PKey::private_key_from_pem(key_file.as_bytes()).unwrap();
+
+    let mut builder = SslAcceptor::mozilla_intermediate(SslMethod::tls()).unwrap();
+    builder.set_certificate(&cert).unwrap();
+    builder.set_private_key(&key).unwrap();
+
+    builder.set_alpn_select_callback(|_, protos| {
+        const H2: &[u8] = b"\x02h2";
+        if protos.windows(3).any(|window| window == H2) {
+            Ok(b"h2")
+        } else {
+            Err(openssl::ssl::AlpnError::NOACK)
+        }
+    });
+    builder.set_alpn_protos(b"\x02h2").unwrap();
+
+    builder.build()
+}
+
 struct TestBody {
     data: Bytes,
     chunk_size: usize,
-    delay: actix_rt::time::Delay,
+    delay: Pin<Box<actix_rt::time::Sleep>>,
 }
 
 impl TestBody {
@@ -53,7 +89,7 @@ impl TestBody {
         TestBody {
             data,
             chunk_size,
-            delay: actix_rt::time::delay_for(std::time::Duration::from_millis(10)),
+            delay: Box::pin(actix_rt::time::sleep(std::time::Duration::from_millis(10))),
         }
     }
 }
@@ -61,13 +97,10 @@ impl TestBody {
 impl futures_core::stream::Stream for TestBody {
     type Item = Result<Bytes, Error>;
 
-    fn poll_next(
-        mut self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         ready!(Pin::new(&mut self.delay).poll(cx));
 
-        self.delay = actix_rt::time::delay_for(std::time::Duration::from_millis(10));
+        self.delay = Box::pin(actix_rt::time::sleep(std::time::Duration::from_millis(10)));
         let chunk_size = std::cmp::min(self.chunk_size, self.data.len());
         let chunk = self.data.split_to(chunk_size);
         if chunk.is_empty() {
@@ -81,8 +114,7 @@ impl futures_core::stream::Stream for TestBody {
 #[actix_rt::test]
 async fn test_body() {
     let srv = test::start(|| {
-        App::new()
-            .service(web::resource("/").route(web::to(|| HttpResponse::Ok().body(STR))))
+        App::new().service(web::resource("/").route(web::to(|| HttpResponse::Ok().body(STR))))
     });
 
     let mut response = srv.get("/").send().await.unwrap();
@@ -104,7 +136,7 @@ async fn test_body_gzip() {
     let mut response = srv
         .get("/")
         .no_decompress()
-        .header(ACCEPT_ENCODING, "gzip")
+        .append_header((ACCEPT_ENCODING, "gzip"))
         .send()
         .await
         .unwrap();
@@ -133,7 +165,7 @@ async fn test_body_gzip2() {
     let mut response = srv
         .get("/")
         .no_decompress()
-        .header(ACCEPT_ENCODING, "gzip")
+        .append_header((ACCEPT_ENCODING, "gzip"))
         .send()
         .await
         .unwrap();
@@ -174,7 +206,7 @@ async fn test_body_encoding_override() {
     let mut response = srv
         .get("/")
         .no_decompress()
-        .header(ACCEPT_ENCODING, "deflate")
+        .append_header((ACCEPT_ENCODING, "deflate"))
         .send()
         .await
         .unwrap();
@@ -193,7 +225,7 @@ async fn test_body_encoding_override() {
     let mut response = srv
         .request(actix_web::http::Method::GET, srv.url("/raw"))
         .no_decompress()
-        .header(ACCEPT_ENCODING, "deflate")
+        .append_header((ACCEPT_ENCODING, "deflate"))
         .send()
         .await
         .unwrap();
@@ -227,7 +259,7 @@ async fn test_body_gzip_large() {
     let mut response = srv
         .get("/")
         .no_decompress()
-        .header(ACCEPT_ENCODING, "gzip")
+        .append_header((ACCEPT_ENCODING, "gzip"))
         .send()
         .await
         .unwrap();
@@ -248,6 +280,7 @@ async fn test_body_gzip_large_random() {
     let data = rand::thread_rng()
         .sample_iter(&Alphanumeric)
         .take(70_000)
+        .map(char::from)
         .collect::<String>();
     let srv_data = data.clone();
 
@@ -264,7 +297,7 @@ async fn test_body_gzip_large_random() {
     let mut response = srv
         .get("/")
         .no_decompress()
-        .header(ACCEPT_ENCODING, "gzip")
+        .append_header((ACCEPT_ENCODING, "gzip"))
         .send()
         .await
         .unwrap();
@@ -295,7 +328,7 @@ async fn test_body_chunked_implicit() {
     let mut response = srv
         .get("/")
         .no_decompress()
-        .header(ACCEPT_ENCODING, "gzip")
+        .append_header((ACCEPT_ENCODING, "gzip"))
         .send()
         .await
         .unwrap();
@@ -318,17 +351,17 @@ async fn test_body_chunked_implicit() {
 #[actix_rt::test]
 async fn test_body_br_streaming() {
     let srv = test::start_with(test::config().h1(), || {
-        App::new().wrap(Compress::new(ContentEncoding::Br)).service(
-            web::resource("/").route(web::to(move || {
+        App::new()
+            .wrap(Compress::new(ContentEncoding::Br))
+            .service(web::resource("/").route(web::to(move || {
                 HttpResponse::Ok()
                     .streaming(TestBody::new(Bytes::from_static(STR.as_ref()), 24))
-            })),
-        )
+            })))
     });
 
     let mut response = srv
         .get("/")
-        .header(ACCEPT_ENCODING, "br")
+        .append_header((ACCEPT_ENCODING, "br"))
         .no_decompress()
         .send()
         .await
@@ -351,8 +384,7 @@ async fn test_body_br_streaming() {
 async fn test_head_binary() {
     let srv = test::start_with(test::config().h1(), || {
         App::new().service(
-            web::resource("/")
-                .route(web::head().to(move || HttpResponse::Ok().body(STR))),
+            web::resource("/").route(web::head().to(move || HttpResponse::Ok().body(STR))),
         )
     });
 
@@ -393,15 +425,13 @@ async fn test_body_deflate() {
     let srv = test::start_with(test::config().h1(), || {
         App::new()
             .wrap(Compress::new(ContentEncoding::Deflate))
-            .service(
-                web::resource("/").route(web::to(move || HttpResponse::Ok().body(STR))),
-            )
+            .service(web::resource("/").route(web::to(move || HttpResponse::Ok().body(STR))))
     });
 
     // client request
     let mut response = srv
         .get("/")
-        .header(ACCEPT_ENCODING, "deflate")
+        .append_header((ACCEPT_ENCODING, "deflate"))
         .no_decompress()
         .send()
         .await
@@ -420,15 +450,15 @@ async fn test_body_deflate() {
 #[actix_rt::test]
 async fn test_body_brotli() {
     let srv = test::start_with(test::config().h1(), || {
-        App::new().wrap(Compress::new(ContentEncoding::Br)).service(
-            web::resource("/").route(web::to(move || HttpResponse::Ok().body(STR))),
-        )
+        App::new()
+            .wrap(Compress::new(ContentEncoding::Br))
+            .service(web::resource("/").route(web::to(move || HttpResponse::Ok().body(STR))))
     });
 
     // client request
     let mut response = srv
         .get("/")
-        .header(ACCEPT_ENCODING, "br")
+        .append_header((ACCEPT_ENCODING, "br"))
         .no_decompress()
         .send()
         .await
@@ -449,8 +479,7 @@ async fn test_body_brotli() {
 async fn test_encoding() {
     let srv = test::start_with(test::config().h1(), || {
         App::new().wrap(Compress::default()).service(
-            web::resource("/")
-                .route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
+            web::resource("/").route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
         )
     });
 
@@ -461,7 +490,7 @@ async fn test_encoding() {
 
     let request = srv
         .post("/")
-        .header(CONTENT_ENCODING, "gzip")
+        .insert_header((CONTENT_ENCODING, "gzip"))
         .send_body(enc.clone());
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -475,8 +504,7 @@ async fn test_encoding() {
 async fn test_gzip_encoding() {
     let srv = test::start_with(test::config().h1(), || {
         App::new().service(
-            web::resource("/")
-                .route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
+            web::resource("/").route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
         )
     });
 
@@ -487,7 +515,7 @@ async fn test_gzip_encoding() {
 
     let request = srv
         .post("/")
-        .header(CONTENT_ENCODING, "gzip")
+        .append_header((CONTENT_ENCODING, "gzip"))
         .send_body(enc.clone());
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -502,8 +530,7 @@ async fn test_gzip_encoding_large() {
     let data = STR.repeat(10);
     let srv = test::start_with(test::config().h1(), || {
         App::new().service(
-            web::resource("/")
-                .route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
+            web::resource("/").route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
         )
     });
 
@@ -514,7 +541,7 @@ async fn test_gzip_encoding_large() {
 
     let request = srv
         .post("/")
-        .header(CONTENT_ENCODING, "gzip")
+        .append_header((CONTENT_ENCODING, "gzip"))
         .send_body(enc.clone());
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -529,12 +556,12 @@ async fn test_reading_gzip_encoding_large_random() {
     let data = rand::thread_rng()
         .sample_iter(&Alphanumeric)
         .take(60_000)
+        .map(char::from)
         .collect::<String>();
 
     let srv = test::start_with(test::config().h1(), || {
         App::new().service(
-            web::resource("/")
-                .route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
+            web::resource("/").route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
         )
     });
 
@@ -545,7 +572,7 @@ async fn test_reading_gzip_encoding_large_random() {
 
     let request = srv
         .post("/")
-        .header(CONTENT_ENCODING, "gzip")
+        .append_header((CONTENT_ENCODING, "gzip"))
         .send_body(enc.clone());
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -560,8 +587,7 @@ async fn test_reading_gzip_encoding_large_random() {
 async fn test_reading_deflate_encoding() {
     let srv = test::start_with(test::config().h1(), || {
         App::new().service(
-            web::resource("/")
-                .route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
+            web::resource("/").route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
         )
     });
 
@@ -572,7 +598,7 @@ async fn test_reading_deflate_encoding() {
     // client request
     let request = srv
         .post("/")
-        .header(CONTENT_ENCODING, "deflate")
+        .append_header((CONTENT_ENCODING, "deflate"))
         .send_body(enc.clone());
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -587,8 +613,7 @@ async fn test_reading_deflate_encoding_large() {
     let data = STR.repeat(10);
     let srv = test::start_with(test::config().h1(), || {
         App::new().service(
-            web::resource("/")
-                .route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
+            web::resource("/").route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
         )
     });
 
@@ -599,7 +624,7 @@ async fn test_reading_deflate_encoding_large() {
     // client request
     let request = srv
         .post("/")
-        .header(CONTENT_ENCODING, "deflate")
+        .append_header((CONTENT_ENCODING, "deflate"))
         .send_body(enc.clone());
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -614,12 +639,12 @@ async fn test_reading_deflate_encoding_large_random() {
     let data = rand::thread_rng()
         .sample_iter(&Alphanumeric)
         .take(160_000)
+        .map(char::from)
         .collect::<String>();
 
     let srv = test::start_with(test::config().h1(), || {
         App::new().service(
-            web::resource("/")
-                .route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
+            web::resource("/").route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
         )
     });
 
@@ -630,7 +655,7 @@ async fn test_reading_deflate_encoding_large_random() {
     // client request
     let request = srv
         .post("/")
-        .header(CONTENT_ENCODING, "deflate")
+        .append_header((CONTENT_ENCODING, "deflate"))
         .send_body(enc.clone());
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -645,8 +670,7 @@ async fn test_reading_deflate_encoding_large_random() {
 async fn test_brotli_encoding() {
     let srv = test::start_with(test::config().h1(), || {
         App::new().service(
-            web::resource("/")
-                .route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
+            web::resource("/").route(web::to(move |body: Bytes| HttpResponse::Ok().body(body))),
         )
     });
 
@@ -657,7 +681,7 @@ async fn test_brotli_encoding() {
     // client request
     let request = srv
         .post("/")
-        .header(CONTENT_ENCODING, "br")
+        .append_header((CONTENT_ENCODING, "br"))
         .send_body(enc.clone());
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -672,6 +696,7 @@ async fn test_brotli_encoding_large() {
     let data = rand::thread_rng()
         .sample_iter(&Alphanumeric)
         .take(320_000)
+        .map(char::from)
         .collect::<String>();
 
     let srv = test::start_with(test::config().h1(), || {
@@ -691,7 +716,7 @@ async fn test_brotli_encoding_large() {
     // client request
     let request = srv
         .post("/")
-        .header(CONTENT_ENCODING, "br")
+        .append_header((CONTENT_ENCODING, "br"))
         .send_body(enc.clone());
     let mut response = request.await.unwrap();
     assert!(response.status().is_success());
@@ -704,18 +729,8 @@ async fn test_brotli_encoding_large() {
 #[cfg(feature = "openssl")]
 #[actix_rt::test]
 async fn test_brotli_encoding_large_openssl() {
-    // load ssl keys
-    use open_ssl::ssl::{SslAcceptor, SslFiletype, SslMethod};
-    let mut builder = SslAcceptor::mozilla_intermediate(SslMethod::tls()).unwrap();
-    builder
-        .set_private_key_file("tests/key.pem", SslFiletype::PEM)
-        .unwrap();
-    builder
-        .set_certificate_chain_file("tests/cert.pem")
-        .unwrap();
-
     let data = STR.repeat(10);
-    let srv = test::start_with(test::config().openssl(builder.build()), move || {
+    let srv = test::start_with(test::config().openssl(openssl_config()), move || {
         App::new().service(web::resource("/").route(web::to(|bytes: Bytes| {
             HttpResponse::Ok()
                 .encoding(actix_web::http::ContentEncoding::Identity)
@@ -731,7 +746,7 @@ async fn test_brotli_encoding_large_openssl() {
     // client request
     let mut response = srv
         .post("/")
-        .header(actix_web::http::header::CONTENT_ENCODING, "br")
+        .append_header((actix_web::http::header::CONTENT_ENCODING, "br"))
         .send_body(enc)
         .await
         .unwrap();
@@ -743,109 +758,126 @@ async fn test_brotli_encoding_large_openssl() {
 }
 
 #[cfg(all(feature = "rustls", feature = "openssl"))]
-#[actix_rt::test]
-async fn test_reading_deflate_encoding_large_random_rustls() {
-    use rust_tls::internal::pemfile::{certs, pkcs8_private_keys};
-    use rust_tls::{NoClientAuth, ServerConfig};
-    use std::fs::File;
+mod plus_rustls {
     use std::io::BufReader;
 
-    let data = rand::thread_rng()
-        .sample_iter(&Alphanumeric)
-        .take(160_000)
-        .collect::<String>();
+    use rustls::{
+        internal::pemfile::{certs, pkcs8_private_keys},
+        NoClientAuth, ServerConfig as RustlsServerConfig,
+    };
 
-    // load ssl keys
-    let mut config = ServerConfig::new(NoClientAuth::new());
-    let cert_file = &mut BufReader::new(File::open("tests/cert.pem").unwrap());
-    let key_file = &mut BufReader::new(File::open("tests/key.pem").unwrap());
-    let cert_chain = certs(cert_file).unwrap();
-    let mut keys = pkcs8_private_keys(key_file).unwrap();
-    config.set_single_cert(cert_chain, keys.remove(0)).unwrap();
+    use super::*;
 
-    let srv = test::start_with(test::config().rustls(config), || {
-        App::new().service(web::resource("/").route(web::to(|bytes: Bytes| {
-            HttpResponse::Ok()
-                .encoding(actix_web::http::ContentEncoding::Identity)
-                .body(bytes)
-        })))
-    });
+    fn rustls_config() -> RustlsServerConfig {
+        let cert = rcgen::generate_simple_self_signed(vec!["localhost".to_owned()]).unwrap();
+        let cert_file = cert.serialize_pem().unwrap();
+        let key_file = cert.serialize_private_key_pem();
 
-    // encode data
-    let mut e = ZlibEncoder::new(Vec::new(), Compression::default());
-    e.write_all(data.as_ref()).unwrap();
-    let enc = e.finish().unwrap();
+        let mut config = RustlsServerConfig::new(NoClientAuth::new());
+        let cert_file = &mut BufReader::new(cert_file.as_bytes());
+        let key_file = &mut BufReader::new(key_file.as_bytes());
 
-    // client request
-    let req = srv
-        .post("/")
-        .header(actix_web::http::header::CONTENT_ENCODING, "deflate")
-        .send_stream(TestBody::new(Bytes::from(enc), 1024));
+        let cert_chain = certs(cert_file).unwrap();
+        let mut keys = pkcs8_private_keys(key_file).unwrap();
+        config.set_single_cert(cert_chain, keys.remove(0)).unwrap();
 
-    let mut response = req.await.unwrap();
-    assert!(response.status().is_success());
+        config
+    }
 
-    // read response
-    let bytes = response.body().await.unwrap();
-    assert_eq!(bytes.len(), data.len());
-    assert_eq!(bytes, Bytes::from(data));
+    #[actix_rt::test]
+    async fn test_reading_deflate_encoding_large_random_rustls() {
+        use rustls::internal::pemfile::{certs, pkcs8_private_keys};
+        use rustls::{NoClientAuth, ServerConfig};
+        use std::fs::File;
+        use std::io::BufReader;
+
+        let data = rand::thread_rng()
+            .sample_iter(&Alphanumeric)
+            .take(160_000)
+            .map(char::from)
+            .collect::<String>();
+
+        let srv = test::start_with(test::config().rustls(rustls_config()), || {
+            App::new().service(web::resource("/").route(web::to(|bytes: Bytes| {
+                HttpResponse::Ok()
+                    .encoding(actix_web::http::ContentEncoding::Identity)
+                    .body(bytes)
+            })))
+        });
+
+        // encode data
+        let mut e = ZlibEncoder::new(Vec::new(), Compression::default());
+        e.write_all(data.as_ref()).unwrap();
+        let enc = e.finish().unwrap();
+
+        // client request
+        let req = srv
+            .post("/")
+            .insert_header((actix_web::http::header::CONTENT_ENCODING, "deflate"))
+            .send_stream(TestBody::new(Bytes::from(enc), 1024));
+
+        let mut response = req.await.unwrap();
+        assert!(response.status().is_success());
+
+        // read response
+        let bytes = response.body().await.unwrap();
+        assert_eq!(bytes.len(), data.len());
+        assert_eq!(bytes, Bytes::from(data));
+    }
 }
 
-// #[test]
-// fn test_server_cookies() {
-//     use actix_web::http;
+#[actix_rt::test]
+async fn test_server_cookies() {
+    use actix_web::{http, HttpMessage};
 
-//     let srv = test::TestServer::with_factory(|| {
-//         App::new().resource("/", |r| {
-//             r.f(|_| {
-//                 HttpResponse::Ok()
-//                     .cookie(
-//                         http::CookieBuilder::new("first", "first_value")
-//                             .http_only(true)
-//                             .finish(),
-//                     )
-//                     .cookie(http::Cookie::new("second", "first_value"))
-//                     .cookie(http::Cookie::new("second", "second_value"))
-//                     .finish()
-//             })
-//         })
-//     });
+    let srv = test::start(|| {
+        App::new().default_service(web::to(|| {
+            HttpResponse::Ok()
+                .cookie(
+                    http::CookieBuilder::new("first", "first_value")
+                        .http_only(true)
+                        .finish(),
+                )
+                .cookie(http::Cookie::new("second", "first_value"))
+                .cookie(http::Cookie::new("second", "second_value"))
+                .finish()
+        }))
+    });
 
-//     let first_cookie = http::CookieBuilder::new("first", "first_value")
-//         .http_only(true)
-//         .finish();
-//     let second_cookie = http::Cookie::new("second", "second_value");
+    let req = srv.get("/");
+    let res = req.send().await.unwrap();
+    assert!(res.status().is_success());
 
-//     let request = srv.get("/").finish().unwrap();
-//     let response = srv.execute(request.send()).unwrap();
-//     assert!(response.status().is_success());
+    let first_cookie = http::CookieBuilder::new("first", "first_value")
+        .http_only(true)
+        .finish();
+    let second_cookie = http::Cookie::new("second", "second_value");
 
-//     let cookies = response.cookies().expect("To have cookies");
-//     assert_eq!(cookies.len(), 2);
-//     if cookies[0] == first_cookie {
-//         assert_eq!(cookies[1], second_cookie);
-//     } else {
-//         assert_eq!(cookies[0], second_cookie);
-//         assert_eq!(cookies[1], first_cookie);
-//     }
+    let cookies = res.cookies().expect("To have cookies");
+    assert_eq!(cookies.len(), 2);
+    if cookies[0] == first_cookie {
+        assert_eq!(cookies[1], second_cookie);
+    } else {
+        assert_eq!(cookies[0], second_cookie);
+        assert_eq!(cookies[1], first_cookie);
+    }
 
-//     let first_cookie = first_cookie.to_string();
-//     let second_cookie = second_cookie.to_string();
-//     //Check that we have exactly two instances of raw cookie headers
-//     let cookies = response
-//         .headers()
-//         .get_all(http::header::SET_COOKIE)
-//         .iter()
-//         .map(|header| header.to_str().expect("To str").to_string())
-//         .collect::<Vec<_>>();
-//     assert_eq!(cookies.len(), 2);
-//     if cookies[0] == first_cookie {
-//         assert_eq!(cookies[1], second_cookie);
-//     } else {
-//         assert_eq!(cookies[0], second_cookie);
-//         assert_eq!(cookies[1], first_cookie);
-//     }
-// }
+    let first_cookie = first_cookie.to_string();
+    let second_cookie = second_cookie.to_string();
+    // Check that we have exactly two instances of raw cookie headers
+    let cookies = res
+        .headers()
+        .get_all(http::header::SET_COOKIE)
+        .map(|header| header.to_str().expect("To str").to_string())
+        .collect::<Vec<_>>();
+    assert_eq!(cookies.len(), 2);
+    if cookies[0] == first_cookie {
+        assert_eq!(cookies[1], second_cookie);
+    } else {
+        assert_eq!(cookies[0], second_cookie);
+        assert_eq!(cookies[1], first_cookie);
+    }
+}
 
 #[actix_rt::test]
 async fn test_slow_request() {
@@ -872,36 +904,9 @@ async fn test_normalize() {
     let srv = test::start_with(test::config().h1(), || {
         App::new()
             .wrap(NormalizePath::new(TrailingSlash::Trim))
-            .service(
-                web::resource("/one").route(web::to(|| HttpResponse::Ok().finish())),
-            )
+            .service(web::resource("/one").route(web::to(|| HttpResponse::Ok().finish())))
     });
 
     let response = srv.get("/one/").send().await.unwrap();
     assert!(response.status().is_success());
 }
-
-// #[cfg(feature = "openssl")]
-// #[actix_rt::test]
-// async fn test_ssl_handshake_timeout() {
-//     use open_ssl::ssl::{SslAcceptor, SslFiletype, SslMethod};
-//     use std::net;
-
-//     // load ssl keys
-//     let mut builder = SslAcceptor::mozilla_intermediate(SslMethod::tls()).unwrap();
-//     builder
-//         .set_private_key_file("tests/key.pem", SslFiletype::PEM)
-//         .unwrap();
-//     builder
-//         .set_certificate_chain_file("tests/cert.pem")
-//         .unwrap();
-
-//     let srv = test::start_with(test::config().openssl(builder.build()), || {
-//         App::new().service(web::resource("/").route(web::to(|| HttpResponse::Ok())))
-//     });
-
-//     let mut stream = net::TcpStream::connect(srv.addr()).unwrap();
-//     let mut data = String::new();
-//     let _ = stream.read_to_string(&mut data);
-//     assert!(data.is_empty());
-// }
diff --git a/tests/test_weird_poll.rs b/tests/test_weird_poll.rs
index 7e4300901..5844ea2c2 100644
--- a/tests/test_weird_poll.rs
+++ b/tests/test_weird_poll.rs
@@ -1,30 +1,30 @@
-// Regression test for #/1321
+//! Regression test for https://github.com/actix/actix-web/issues/1321
 
-/*
-use futures::task::{noop_waker, Context};
-use futures::stream::once;
-use actix_http::body::{MessageBody, BodyStream};
-use bytes::Bytes;
+// use actix_http::body::{BodyStream, MessageBody};
+// use bytes::Bytes;
+// use futures_channel::oneshot;
+// use futures_util::{
+//     stream::once,
+//     task::{noop_waker, Context},
+// };
 
-Disable weird poll until actix-web is based on actix-http 2.0.0
+// #[test]
+// fn weird_poll() {
+//     let (sender, receiver) = oneshot::channel();
+//     let mut body_stream = Ok(BodyStream::new(once(async {
+//         let x = Box::new(0);
+//         let y = &x;
+//         receiver.await.unwrap();
+//         let _z = **y;
+//         Ok::<_, ()>(Bytes::new())
+//     })));
 
-#[test]
-fn weird_poll() {
-    let (sender, receiver) = futures::channel::oneshot::channel();
-    let mut body_stream = Ok(BodyStream::new(once(async {
-        let x = Box::new(0);
-        let y = &x;
-        receiver.await.unwrap();
-        let _z = **y;
-        Ok::<_, ()>(Bytes::new())
-    })));
+//     let waker = noop_waker();
+//     let mut cx = Context::from_waker(&waker);
 
-    let waker = noop_waker();
-    let mut context = Context::from_waker(&waker);
-
-    let _ = body_stream.as_mut().unwrap().poll_next(&mut context);
-    sender.send(()).unwrap();
-    let _ = std::mem::replace(&mut body_stream, Err([0; 32])).unwrap().poll_next(&mut context);
-}
-
-*/
+//     let _ = body_stream.as_mut().unwrap().poll_next(&mut cx);
+//     sender.send(()).unwrap();
+//     let _ = std::mem::replace(&mut body_stream, Err([0; 32]))
+//         .unwrap()
+//         .poll_next(&mut cx);
+// }