From 373b3f91dff58ac6c5b1158206e7380376906541 Mon Sep 17 00:00:00 2001
From: Ali MJ Al-Nasrawy <alimjalnasrawy@gmail.com>
Date: Wed, 1 Sep 2021 06:48:43 +0300
Subject: [PATCH 1/3] rework `ResourceMap` internals (#2337)

---
 src/app_service.rs |   4 +-
 src/request.rs     |   9 +-
 src/rmap.rs        | 422 ++++++++++++++++++++++++---------------------
 3 files changed, 233 insertions(+), 202 deletions(-)

diff --git a/src/app_service.rs b/src/app_service.rs
index ce52543b8..cf34b302e 100644
--- a/src/app_service.rs
+++ b/src/app_service.rs
@@ -79,7 +79,7 @@ where
             .into_iter()
             .for_each(|mut srv| srv.register(&mut config));
 
-        let mut rmap = ResourceMap::new(ResourceDef::new(""));
+        let mut rmap = ResourceMap::new(ResourceDef::prefix(""));
 
         let (config, services) = config.into_services();
 
@@ -104,7 +104,7 @@ where
 
         // complete ResourceMap tree creation
         let rmap = Rc::new(rmap);
-        rmap.finish(rmap.clone());
+        ResourceMap::finish(&rmap);
 
         // construct all async data factory futures
         let factory_futs = join_all(self.async_data_factories.iter().map(|f| f()));
diff --git a/src/request.rs b/src/request.rs
index 59850b4ca..c25a5397a 100644
--- a/src/request.rs
+++ b/src/request.rs
@@ -511,7 +511,7 @@ mod tests {
         let mut res = ResourceDef::new("/user/{name}.{ext}");
         res.set_name("index");
 
-        let mut rmap = ResourceMap::new(ResourceDef::new(""));
+        let mut rmap = ResourceMap::new(ResourceDef::prefix(""));
         rmap.add(&mut res, None);
         assert!(rmap.has_resource("/user/test.html"));
         assert!(!rmap.has_resource("/test/unknown"));
@@ -541,7 +541,7 @@ mod tests {
         let mut rdef = ResourceDef::new("/index.html");
         rdef.set_name("index");
 
-        let mut rmap = ResourceMap::new(ResourceDef::new(""));
+        let mut rmap = ResourceMap::new(ResourceDef::prefix(""));
         rmap.add(&mut rdef, None);
 
         assert!(rmap.has_resource("/index.html"));
@@ -562,7 +562,7 @@ mod tests {
         let mut rdef = ResourceDef::new("/index.html");
         rdef.set_name("index");
 
-        let mut rmap = ResourceMap::new(ResourceDef::new(""));
+        let mut rmap = ResourceMap::new(ResourceDef::prefix(""));
         rmap.add(&mut rdef, None);
 
         assert!(rmap.has_resource("/index.html"));
@@ -581,9 +581,8 @@ mod tests {
 
         rdef.set_name("youtube");
 
-        let mut rmap = ResourceMap::new(ResourceDef::new(""));
+        let mut rmap = ResourceMap::new(ResourceDef::prefix(""));
         rmap.add(&mut rdef, None);
-        assert!(rmap.has_resource("https://youtube.com/watch/unknown"));
 
         let req = TestRequest::default().rmap(rmap).to_http_request();
         let url = req.url_for("youtube", &["oHg5SJYRHA0"]);
diff --git a/src/rmap.rs b/src/rmap.rs
index 0ee4de47e..8466eda28 100644
--- a/src/rmap.rs
+++ b/src/rmap.rs
@@ -10,43 +10,75 @@ use crate::request::HttpRequest;
 
 #[derive(Clone, Debug)]
 pub struct ResourceMap {
-    root: ResourceDef,
+    pattern: ResourceDef,
+
+    /// Named resources within the tree or, for external resources,
+    /// it points to isolated nodes outside the tree.
+    named: AHashMap<String, Rc<ResourceMap>>,
+
     parent: RefCell<Weak<ResourceMap>>,
-    named: AHashMap<String, ResourceDef>,
-    patterns: Vec<(ResourceDef, Option<Rc<ResourceMap>>)>,
+
+    /// Must be `None` for "edge" nodes.
+    nodes: Option<Vec<Rc<ResourceMap>>>,
 }
 
 impl ResourceMap {
+    /// Creates a _container_ node in the `ResourceMap` tree.
     pub fn new(root: ResourceDef) -> Self {
         ResourceMap {
-            root,
-            parent: RefCell::new(Weak::new()),
+            pattern: root,
             named: AHashMap::default(),
-            patterns: Vec::new(),
+            parent: RefCell::new(Weak::new()),
+            nodes: Some(Vec::new()),
         }
     }
 
+    /// Adds a (possibly nested) resource.
+    ///
+    /// To add a non-prefix pattern, `nested` must be `None`.
+    /// To add external resource, supply a pattern without a leading `/`.
+    /// The root pattern of `nested`, if present, should match `pattern`.
     pub fn add(&mut self, pattern: &mut ResourceDef, nested: Option<Rc<ResourceMap>>) {
-        pattern.set_id(self.patterns.len() as u16);
-        self.patterns.push((pattern.clone(), nested));
-        if let Some(name) = pattern.name() {
-            self.named.insert(name.to_owned(), pattern.clone());
+        pattern.set_id(self.nodes.as_ref().unwrap().len() as u16);
+
+        if let Some(new_node) = nested {
+            assert_eq!(&new_node.pattern, pattern, "`patern` and `nested` mismatch");
+            self.named.extend(new_node.named.clone().into_iter());
+            self.nodes.as_mut().unwrap().push(new_node);
+        } else {
+            let new_node = Rc::new(ResourceMap {
+                pattern: pattern.clone(),
+                named: AHashMap::default(),
+                parent: RefCell::new(Weak::new()),
+                nodes: None,
+            });
+
+            if let Some(name) = pattern.name() {
+                self.named.insert(name.to_owned(), Rc::clone(&new_node));
+            }
+
+            let is_external = match pattern.pattern() {
+                Some(p) => !p.is_empty() && !p.starts_with('/'),
+                None => false,
+            };
+
+            // Don't add external resources to the tree
+            if !is_external {
+                self.nodes.as_mut().unwrap().push(new_node);
+            }
         }
     }
 
-    pub(crate) fn finish(&self, current: Rc<ResourceMap>) {
-        for (_, nested) in &self.patterns {
-            if let Some(ref nested) = nested {
-                *nested.parent.borrow_mut() = Rc::downgrade(&current);
-                nested.finish(nested.clone());
-            }
+    pub(crate) fn finish(self: &Rc<Self>) {
+        for node in self.nodes.iter().flatten() {
+            node.parent.replace(Rc::downgrade(self));
+            ResourceMap::finish(node);
         }
     }
 
     /// Generate url for named resource
     ///
-    /// Check [`HttpRequest::url_for()`](../struct.HttpRequest.html#method.
-    /// url_for) for detailed information.
+    /// Check [`HttpRequest::url_for`] for detailed information.
     pub fn url_for<U, I>(
         &self,
         req: &HttpRequest,
@@ -57,197 +89,97 @@ impl ResourceMap {
         U: IntoIterator<Item = I>,
         I: AsRef<str>,
     {
-        let mut path = String::new();
         let mut elements = elements.into_iter();
 
-        if self.patterns_for(name, &mut path, &mut elements)?.is_some() {
-            if path.starts_with('/') {
-                let conn = req.connection_info();
-                Ok(Url::parse(&format!(
-                    "{}://{}{}",
-                    conn.scheme(),
-                    conn.host(),
-                    path
-                ))?)
-            } else {
-                Ok(Url::parse(&path)?)
-            }
+        let path = self
+            .named
+            .get(name)
+            .ok_or(UrlGenerationError::ResourceNotFound)?
+            .root_rmap_fn(String::with_capacity(24), |mut acc, node| {
+                node.pattern
+                    .resource_path_from_iter(&mut acc, &mut elements)
+                    .then(|| acc)
+            })
+            .ok_or(UrlGenerationError::NotEnoughElements)?;
+
+        if path.starts_with('/') {
+            let conn = req.connection_info();
+            Ok(Url::parse(&format!(
+                "{}://{}{}",
+                conn.scheme(),
+                conn.host(),
+                path
+            ))?)
         } else {
-            Err(UrlGenerationError::ResourceNotFound)
+            Ok(Url::parse(&path)?)
         }
     }
 
     pub fn has_resource(&self, path: &str) -> bool {
-        let path = if path.is_empty() { "/" } else { path };
-
-        for (pattern, rmap) in &self.patterns {
-            if let Some(ref rmap) = rmap {
-                if let Some(pat_len) = pattern.find_match(path) {
-                    return rmap.has_resource(&path[pat_len..]);
-                }
-            } else if pattern.is_match(path) || pattern.pattern() == Some("") && path == "/" {
-                return true;
-            }
-        }
-        false
+        self.find_matching_node(path).is_some()
     }
 
     /// Returns the name of the route that matches the given path or None if no full match
-    /// is possible.
+    /// is possible or the matching resource is not named.
     pub fn match_name(&self, path: &str) -> Option<&str> {
-        let path = if path.is_empty() { "/" } else { path };
-
-        for (pattern, rmap) in &self.patterns {
-            if let Some(ref rmap) = rmap {
-                if let Some(plen) = pattern.find_match(path) {
-                    return rmap.match_name(&path[plen..]);
-                }
-            } else if pattern.is_match(path) {
-                return pattern.name();
-            }
-        }
-
-        None
+        self.find_matching_node(path)?.pattern.name()
     }
 
     /// Returns the full resource pattern matched against a path or None if no full match
     /// is possible.
     pub fn match_pattern(&self, path: &str) -> Option<String> {
-        let path = if path.is_empty() { "/" } else { path };
-
-        // ensure a full match exists
-        if !self.has_resource(path) {
-            return None;
-        }
-
-        Some(self.traverse_resource_pattern(path))
+        self.find_matching_node(path)?.root_rmap_fn(
+            String::with_capacity(24),
+            |mut acc, node| {
+                acc.push_str(node.pattern.pattern()?);
+                Some(acc)
+            },
+        )
     }
 
-    /// Takes remaining path and tries to match it up against a resource definition within the
-    /// current resource map recursively, returning a concatenation of all resource prefixes and
-    /// patterns matched in the tree.
-    ///
-    /// Should only be used after checking the resource exists in the map so that partial match
-    /// patterns are not returned.
-    fn traverse_resource_pattern(&self, remaining: &str) -> String {
-        for (pattern, rmap) in &self.patterns {
-            if let Some(ref rmap) = rmap {
-                if let Some(prefix_len) = pattern.find_match(remaining) {
-                    // TODO: think about unwrap_or
-                    let prefix = pattern.pattern().unwrap_or("").to_owned();
-
-                    return [
-                        prefix,
-                        rmap.traverse_resource_pattern(&remaining[prefix_len..]),
-                    ]
-                    .concat();
-                }
-            } else if pattern.is_match(remaining) {
-                // TODO: think about unwrap_or
-                return pattern.pattern().unwrap_or("").to_owned();
-            }
-        }
-
-        String::new()
+    fn find_matching_node(&self, path: &str) -> Option<&ResourceMap> {
+        self._find_matching_node(path).flatten()
     }
 
-    fn patterns_for<U, I>(
-        &self,
-        name: &str,
-        path: &mut String,
-        elements: &mut U,
-    ) -> Result<Option<()>, UrlGenerationError>
+    /// Returns `None` if root pattern doesn't match;
+    /// `Some(None)` if root pattern matches but there is no matching child pattern.
+    /// Don't search sideways when `Some(none)` is returned.
+    fn _find_matching_node(&self, path: &str) -> Option<Option<&ResourceMap>> {
+        let matched_len = self.pattern.find_match(path)?;
+        let path = &path[matched_len..];
+
+        Some(match &self.nodes {
+            // find first sub-node to match remaining path
+            Some(nodes) => nodes
+                .iter()
+                .filter_map(|node| node._find_matching_node(path))
+                .next()
+                .flatten(),
+
+            // only terminate at edge nodes
+            None => Some(self),
+        })
+    }
+
+    /// Find `self`'s highest ancestor and then run `F`, providing `B`, in that rmap context.
+    fn root_rmap_fn<F, B>(&self, init: B, mut f: F) -> Option<B>
     where
-        U: Iterator<Item = I>,
-        I: AsRef<str>,
+        F: FnMut(B, &ResourceMap) -> Option<B>,
     {
-        if self.pattern_for(name, path, elements)?.is_some() {
-            Ok(Some(()))
-        } else {
-            self.parent_pattern_for(name, path, elements)
-        }
+        self._root_rmap_fn(init, &mut f)
     }
 
-    fn pattern_for<U, I>(
-        &self,
-        name: &str,
-        path: &mut String,
-        elements: &mut U,
-    ) -> Result<Option<()>, UrlGenerationError>
+    /// Run `F`, providing `B`, if `self` is top-level resource map, else recurse to parent map.
+    fn _root_rmap_fn<F, B>(&self, init: B, f: &mut F) -> Option<B>
     where
-        U: Iterator<Item = I>,
-        I: AsRef<str>,
+        F: FnMut(B, &ResourceMap) -> Option<B>,
     {
-        if let Some(pattern) = self.named.get(name) {
-            if pattern
-                .pattern()
-                .map(|pat| pat.starts_with('/'))
-                .unwrap_or(false)
-            {
-                self.fill_root(path, elements)?;
-            }
+        let data = match self.parent.borrow().upgrade() {
+            Some(ref parent) => parent._root_rmap_fn(init, f)?,
+            None => init,
+        };
 
-            if pattern.resource_path_from_iter(path, elements) {
-                Ok(Some(()))
-            } else {
-                Err(UrlGenerationError::NotEnoughElements)
-            }
-        } else {
-            for (_, rmap) in &self.patterns {
-                if let Some(ref rmap) = rmap {
-                    if rmap.pattern_for(name, path, elements)?.is_some() {
-                        return Ok(Some(()));
-                    }
-                }
-            }
-            Ok(None)
-        }
-    }
-
-    fn fill_root<U, I>(
-        &self,
-        path: &mut String,
-        elements: &mut U,
-    ) -> Result<(), UrlGenerationError>
-    where
-        U: Iterator<Item = I>,
-        I: AsRef<str>,
-    {
-        if let Some(ref parent) = self.parent.borrow().upgrade() {
-            parent.fill_root(path, elements)?;
-        }
-
-        if self.root.resource_path_from_iter(path, elements) {
-            Ok(())
-        } else {
-            Err(UrlGenerationError::NotEnoughElements)
-        }
-    }
-
-    fn parent_pattern_for<U, I>(
-        &self,
-        name: &str,
-        path: &mut String,
-        elements: &mut U,
-    ) -> Result<Option<()>, UrlGenerationError>
-    where
-        U: Iterator<Item = I>,
-        I: AsRef<str>,
-    {
-        if let Some(ref parent) = self.parent.borrow().upgrade() {
-            if let Some(pattern) = parent.named.get(name) {
-                self.fill_root(path, elements)?;
-                if pattern.resource_path_from_iter(path, elements) {
-                    Ok(Some(()))
-                } else {
-                    Err(UrlGenerationError::NotEnoughElements)
-                }
-            } else {
-                parent.parent_pattern_for(name, path, elements)
-            }
-        } else {
-            Ok(None)
-        }
+        f(data, self)
     }
 }
 
@@ -259,7 +191,7 @@ mod tests {
     fn extract_matched_pattern() {
         let mut root = ResourceMap::new(ResourceDef::root_prefix(""));
 
-        let mut user_map = ResourceMap::new(ResourceDef::root_prefix(""));
+        let mut user_map = ResourceMap::new(ResourceDef::root_prefix("/user/{id}"));
         user_map.add(&mut ResourceDef::new("/"), None);
         user_map.add(&mut ResourceDef::new("/profile"), None);
         user_map.add(&mut ResourceDef::new("/article/{id}"), None);
@@ -275,9 +207,10 @@ mod tests {
             &mut ResourceDef::root_prefix("/user/{id}"),
             Some(Rc::new(user_map)),
         );
+        root.add(&mut ResourceDef::new("/info"), None);
 
         let root = Rc::new(root);
-        root.finish(Rc::clone(&root));
+        ResourceMap::finish(&root);
 
         // sanity check resource map setup
 
@@ -288,7 +221,7 @@ mod tests {
         assert!(root.has_resource("/v2"));
         assert!(!root.has_resource("/v33"));
 
-        assert!(root.has_resource("/user/22"));
+        assert!(!root.has_resource("/user/22"));
         assert!(root.has_resource("/user/22/"));
         assert!(root.has_resource("/user/22/profile"));
 
@@ -336,7 +269,7 @@ mod tests {
         rdef.set_name("root_info");
         root.add(&mut rdef, None);
 
-        let mut user_map = ResourceMap::new(ResourceDef::root_prefix(""));
+        let mut user_map = ResourceMap::new(ResourceDef::root_prefix("/user/{id}"));
         let mut rdef = ResourceDef::new("/");
         user_map.add(&mut rdef, None);
 
@@ -350,14 +283,14 @@ mod tests {
         );
 
         let root = Rc::new(root);
-        root.finish(Rc::clone(&root));
+        ResourceMap::finish(&root);
 
         // sanity check resource map setup
 
         assert!(root.has_resource("/info"));
         assert!(!root.has_resource("/bar"));
 
-        assert!(root.has_resource("/user/22"));
+        assert!(!root.has_resource("/user/22"));
         assert!(root.has_resource("/user/22/"));
         assert!(root.has_resource("/user/22/post/55"));
 
@@ -377,7 +310,7 @@ mod tests {
         // ref: https://github.com/actix/actix-web/issues/1582
         let mut root = ResourceMap::new(ResourceDef::root_prefix(""));
 
-        let mut user_map = ResourceMap::new(ResourceDef::root_prefix(""));
+        let mut user_map = ResourceMap::new(ResourceDef::root_prefix("/user/{id}"));
         user_map.add(&mut ResourceDef::new("/"), None);
         user_map.add(&mut ResourceDef::new("/profile"), None);
         user_map.add(&mut ResourceDef::new("/article/{id}"), None);
@@ -393,20 +326,119 @@ mod tests {
         );
 
         let root = Rc::new(root);
-        root.finish(Rc::clone(&root));
+        ResourceMap::finish(&root);
 
         // check root has no parent
         assert!(root.parent.borrow().upgrade().is_none());
         // check child has parent reference
-        assert!(root.patterns[0].1.is_some());
+        assert!(root.nodes.as_ref().unwrap()[0]
+            .parent
+            .borrow()
+            .upgrade()
+            .is_some());
         // check child's parent root id matches root's root id
-        assert_eq!(
-            root.patterns[0].1.as_ref().unwrap().root.id(),
-            root.root.id()
-        );
+        assert!(Rc::ptr_eq(
+            &root.nodes.as_ref().unwrap()[0]
+                .parent
+                .borrow()
+                .upgrade()
+                .unwrap(),
+            &root
+        ));
 
         let output = format!("{:?}", root);
         assert!(output.starts_with("ResourceMap {"));
         assert!(output.ends_with(" }"));
     }
+
+    #[test]
+    fn short_circuit() {
+        let mut root = ResourceMap::new(ResourceDef::prefix(""));
+
+        let mut user_root = ResourceDef::prefix("/user");
+        let mut user_map = ResourceMap::new(user_root.clone());
+        user_map.add(&mut ResourceDef::new("/u1"), None);
+        user_map.add(&mut ResourceDef::new("/u2"), None);
+
+        root.add(&mut ResourceDef::new("/user/u3"), None);
+        root.add(&mut user_root, Some(Rc::new(user_map)));
+        root.add(&mut ResourceDef::new("/user/u4"), None);
+
+        let rmap = Rc::new(root);
+        ResourceMap::finish(&rmap);
+
+        assert!(rmap.has_resource("/user/u1"));
+        assert!(rmap.has_resource("/user/u2"));
+        assert!(rmap.has_resource("/user/u3"));
+        assert!(!rmap.has_resource("/user/u4"));
+    }
+
+    #[test]
+    fn url_for() {
+        let mut root = ResourceMap::new(ResourceDef::prefix(""));
+
+        let mut user_scope_rdef = ResourceDef::prefix("/user");
+        let mut user_scope_map = ResourceMap::new(user_scope_rdef.clone());
+
+        let mut user_rdef = ResourceDef::new("/{user_id}");
+        let mut user_map = ResourceMap::new(user_rdef.clone());
+
+        let mut post_rdef = ResourceDef::new("/post/{sub_id}");
+        post_rdef.set_name("post");
+
+        user_map.add(&mut post_rdef, None);
+        user_scope_map.add(&mut user_rdef, Some(Rc::new(user_map)));
+        root.add(&mut user_scope_rdef, Some(Rc::new(user_scope_map)));
+
+        let rmap = Rc::new(root);
+        ResourceMap::finish(&rmap);
+
+        let mut req = crate::test::TestRequest::default();
+        req.set_server_hostname("localhost:8888");
+        let req = req.to_http_request();
+
+        let url = rmap
+            .url_for(&req, "post", &["u123", "foobar"])
+            .unwrap()
+            .to_string();
+        assert_eq!(url, "http://localhost:8888/user/u123/post/foobar");
+
+        assert!(rmap.url_for(&req, "missing", &["u123"]).is_err());
+    }
+
+    #[test]
+    fn external_resource_with_no_name() {
+        let mut root = ResourceMap::new(ResourceDef::prefix(""));
+
+        let mut rdef = ResourceDef::new("https://duck.com/{query}");
+        root.add(&mut rdef, None);
+
+        let rmap = Rc::new(root);
+        ResourceMap::finish(&rmap);
+
+        assert!(!rmap.has_resource("https://duck.com/abc"));
+    }
+
+    #[test]
+    fn external_resource_with_name() {
+        let mut root = ResourceMap::new(ResourceDef::prefix(""));
+
+        let mut rdef = ResourceDef::new("https://duck.com/{query}");
+        rdef.set_name("duck");
+        root.add(&mut rdef, None);
+
+        let rmap = Rc::new(root);
+        ResourceMap::finish(&rmap);
+
+        assert!(!rmap.has_resource("https://duck.com/abc"));
+
+        let mut req = crate::test::TestRequest::default();
+        req.set_server_hostname("localhost:8888");
+        let req = req.to_http_request();
+
+        assert_eq!(
+            rmap.url_for(&req, "duck", &["abcd"]).unwrap().to_string(),
+            "https://duck.com/abcd"
+        );
+    }
 }

From ddc8c16cb34c9730b9a4922413fbf027e401052d Mon Sep 17 00:00:00 2001
From: Arthur Le Moigne <arthurlm@users.noreply.github.com>
Date: Wed, 1 Sep 2021 10:08:29 +0200
Subject: [PATCH 2/3] Fix quality parse error in Accept-Encoding HTTP header
 (#2344)

---
 CHANGES.md                                    |   7 +-
 actix-http/CHANGES.md                         |   5 +-
 actix-http/src/encoding/decoder.rs            |   3 +-
 .../src/header/shared/content_encoding.rs     |  56 ++---
 actix-http/src/header/shared/quality_item.rs  |  29 ++-
 src/middleware/compress.rs                    | 217 +++++++++++++++---
 tests/test_server.rs                          |  19 ++
 7 files changed, 259 insertions(+), 77 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index 5325caf48..217ec4f78 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -4,10 +4,15 @@
 ### Added
 * Re-export actix-service `ServiceFactory` in `dev` module. [#2325]
 
-### Changes
+### Changed
 * Minimum supported Rust version (MSRV) is now 1.51.
+* Compress middleware will return 406 Not Acceptable when no content encoding is acceptable to the client. [#2344]
+
+### Fixed
+* Fix quality parse error in Accept-Encoding header. [#2344]
 
 [#2325]: https://github.com/actix/actix-web/pull/2325
+[#2344]: https://github.com/actix/actix-web/pull/2344
 
 
 ## 4.0.0-beta.8 - 2021-06-26
diff --git a/actix-http/CHANGES.md b/actix-http/CHANGES.md
index 63172e56d..f4efef54a 100644
--- a/actix-http/CHANGES.md
+++ b/actix-http/CHANGES.md
@@ -1,22 +1,23 @@
 # Changes
 
 ## Unreleased - 2021-xx-xx
-### Changes
+### Changed
 * Minimum supported Rust version (MSRV) is now 1.51.
 
 ### Fixed
 * Remove slice creation pointing to potential uninitialized data on h1 encoder. [#2364]
 * Remove `Into<Error>` bound on `Encoder` body types. [#2375]
+* Fix quality parse error in Accept-Encoding header. [#2344]
 
 [#2364]: https://github.com/actix/actix-web/pull/2364
 [#2375]: https://github.com/actix/actix-web/pull/2375
+[#2344]: https://github.com/actix/actix-web/pull/2344
 
 
 ## 3.0.0-beta.8 - 2021-08-09
 ### Fixed
 * Potential HTTP request smuggling vulnerabilities. [RUSTSEC-2021-0081](https://github.com/rustsec/advisory-db/pull/977)
 
-
 ## 3.0.0-beta.8 - 2021-06-26
 ### Changed
 * Change compression algorithm features flags. [#2250]
diff --git a/actix-http/src/encoding/decoder.rs b/actix-http/src/encoding/decoder.rs
index d3e304836..81e97d916 100644
--- a/actix-http/src/encoding/decoder.rs
+++ b/actix-http/src/encoding/decoder.rs
@@ -1,6 +1,7 @@
 //! Stream decoders.
 
 use std::{
+    convert::TryFrom,
     future::Future,
     io::{self, Write as _},
     pin::Pin,
@@ -80,7 +81,7 @@ where
         let encoding = headers
             .get(&CONTENT_ENCODING)
             .and_then(|val| val.to_str().ok())
-            .map(ContentEncoding::from)
+            .and_then(|x| ContentEncoding::try_from(x).ok())
             .unwrap_or(ContentEncoding::Identity);
 
         Self::new(stream, encoding)
diff --git a/actix-http/src/header/shared/content_encoding.rs b/actix-http/src/header/shared/content_encoding.rs
index b9c1d2795..375e8c2fa 100644
--- a/actix-http/src/header/shared/content_encoding.rs
+++ b/actix-http/src/header/shared/content_encoding.rs
@@ -1,4 +1,4 @@
-use std::{convert::Infallible, str::FromStr};
+use std::{convert::TryFrom, error, fmt, str::FromStr};
 
 use http::header::InvalidHeaderValue;
 
@@ -8,6 +8,20 @@ use crate::{
     HttpMessage,
 };
 
+/// Error return when a content encoding is unknown.
+///
+/// Example: 'compress'
+#[derive(Debug)]
+pub struct ContentEncodingParseError;
+
+impl fmt::Display for ContentEncodingParseError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Unsupported content encoding")
+    }
+}
+
+impl error::Error for ContentEncodingParseError {}
+
 /// Represents a supported content encoding.
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub enum ContentEncoding {
@@ -37,7 +51,7 @@ impl ContentEncoding {
         matches!(self, ContentEncoding::Identity | ContentEncoding::Auto)
     }
 
-    /// Convert content encoding to string
+    /// Convert content encoding to string.
     #[inline]
     pub fn as_str(self) -> &'static str {
         match self {
@@ -48,18 +62,6 @@ impl ContentEncoding {
             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,
-            ContentEncoding::Zstd => 0.0,
-        }
-    }
 }
 
 impl Default for ContentEncoding {
@@ -69,31 +71,33 @@ impl Default for ContentEncoding {
 }
 
 impl FromStr for ContentEncoding {
-    type Err = Infallible;
+    type Err = ContentEncodingParseError;
 
     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
+            Ok(ContentEncoding::Br)
         } else if val.eq_ignore_ascii_case("gzip") {
-            ContentEncoding::Gzip
+            Ok(ContentEncoding::Gzip)
         } else if val.eq_ignore_ascii_case("deflate") {
-            ContentEncoding::Deflate
+            Ok(ContentEncoding::Deflate)
         } else if val.eq_ignore_ascii_case("zstd") {
-            ContentEncoding::Zstd
+            Ok(ContentEncoding::Zstd)
         } else {
-            ContentEncoding::default()
+            Err(ContentEncodingParseError)
         }
     }
 }
 
+impl TryFrom<&str> for ContentEncoding {
+    type Error = ContentEncodingParseError;
+
+    fn try_from(val: &str) -> Result<Self, Self::Error> {
+        val.parse()
+    }
+}
+
 impl IntoHeaderValue for ContentEncoding {
     type Error = InvalidHeaderValue;
 
diff --git a/actix-http/src/header/shared/quality_item.rs b/actix-http/src/header/shared/quality_item.rs
index 240a0afa2..63fa02e7b 100644
--- a/actix-http/src/header/shared/quality_item.rs
+++ b/actix-http/src/header/shared/quality_item.rs
@@ -1,11 +1,14 @@
 use std::{
     cmp,
     convert::{TryFrom, TryInto},
-    fmt, str,
+    fmt,
+    str::{self, FromStr},
 };
 
 use derive_more::{Display, Error};
 
+use crate::error::ParseError;
+
 const MAX_QUALITY: u16 = 1000;
 const MAX_FLOAT_QUALITY: f32 = 1.0;
 
@@ -113,12 +116,12 @@ impl<T: fmt::Display> fmt::Display for QualityItem<T> {
     }
 }
 
-impl<T: str::FromStr> str::FromStr for QualityItem<T> {
-    type Err = crate::error::ParseError;
+impl<T: FromStr> FromStr for QualityItem<T> {
+    type Err = ParseError;
 
-    fn from_str(qitem_str: &str) -> Result<QualityItem<T>, crate::error::ParseError> {
+    fn from_str(qitem_str: &str) -> Result<Self, Self::Err> {
         if !qitem_str.is_ascii() {
-            return Err(crate::error::ParseError::Header);
+            return Err(ParseError::Header);
         }
 
         // Set defaults used if parsing fails.
@@ -139,7 +142,7 @@ impl<T: str::FromStr> str::FromStr for QualityItem<T> {
             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);
+                return Err(ParseError::Header);
             }
 
             let start = &parts[0][0..2];
@@ -148,25 +151,21 @@ impl<T: str::FromStr> str::FromStr for QualityItem<T> {
                 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);
+                    return Err(ParseError::Header);
                 }
 
-                let q_value = q_val
-                    .parse::<f32>()
-                    .map_err(|_| crate::error::ParseError::Header)?;
+                let q_value = q_val.parse::<f32>().map_err(|_| ParseError::Header)?;
 
                 if (0f32..=1f32).contains(&q_value) {
                     quality = q_value;
                     raw_item = parts[1];
                 } else {
-                    return Err(crate::error::ParseError::Header);
+                    return Err(ParseError::Header);
                 }
             }
         }
 
-        let item = raw_item
-            .parse::<T>()
-            .map_err(|_| crate::error::ParseError::Header)?;
+        let item = raw_item.parse::<T>().map_err(|_| ParseError::Header)?;
 
         // we already checked above that the quality is within range
         Ok(QualityItem::new(item, Quality::from_f32(quality)))
@@ -224,7 +223,7 @@ mod tests {
         }
     }
 
-    impl str::FromStr for Encoding {
+    impl FromStr for Encoding {
         type Err = crate::error::ParseError;
         fn from_str(s: &str) -> Result<Encoding, crate::error::ParseError> {
             use Encoding::*;
diff --git a/src/middleware/compress.rs b/src/middleware/compress.rs
index a9128bc47..0e61a8e7e 100644
--- a/src/middleware/compress.rs
+++ b/src/middleware/compress.rs
@@ -2,10 +2,10 @@
 
 use std::{
     cmp,
+    convert::TryFrom,
     future::Future,
     marker::PhantomData,
     pin::Pin,
-    str::FromStr,
     task::{Context, Poll},
 };
 
@@ -13,16 +13,18 @@ use actix_http::{
     body::{MessageBody, ResponseBody},
     encoding::Encoder,
     http::header::{ContentEncoding, ACCEPT_ENCODING},
+    StatusCode,
 };
 use actix_service::{Service, Transform};
-use actix_utils::future::{ok, Ready};
+use actix_utils::future::{ok, Either, Ready};
 use futures_core::ready;
+use once_cell::sync::Lazy;
 use pin_project::pin_project;
 
 use crate::{
     dev::BodyEncoding,
     service::{ServiceRequest, ServiceResponse},
-    Error,
+    Error, HttpResponse,
 };
 
 /// Middleware for compressing response payloads.
@@ -78,34 +80,78 @@ pub struct CompressMiddleware<S> {
     encoding: ContentEncoding,
 }
 
+static SUPPORTED_ALGORITHM_NAMES: Lazy<String> = Lazy::new(|| {
+    let mut encoding = vec![];
+
+    #[cfg(feature = "compress-brotli")]
+    {
+        encoding.push("br");
+    }
+
+    #[cfg(feature = "compress-gzip")]
+    {
+        encoding.push("gzip");
+        encoding.push("deflate");
+    }
+
+    #[cfg(feature = "compress-zstd")]
+    encoding.push("zstd");
+
+    assert!(
+        !encoding.is_empty(),
+        "encoding can not be empty unless __compress feature has been explicitly enabled by itself"
+    );
+
+    encoding.join(", ")
+});
+
 impl<S, B> Service<ServiceRequest> for CompressMiddleware<S>
 where
-    B: MessageBody,
     S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    B: MessageBody,
 {
     type Response = ServiceResponse<ResponseBody<Encoder<B>>>;
     type Error = Error;
-    type Future = CompressResponse<S, B>;
+    type Future = Either<CompressResponse<S, B>, Ready<Result<Self::Response, Self::Error>>>;
 
     actix_service::forward_ready!(service);
 
     #[allow(clippy::borrow_interior_mutable_const)]
     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() {
-                AcceptEncoding::parse(enc, self.encoding)
-            } else {
-                ContentEncoding::Identity
-            }
-        } else {
-            ContentEncoding::Identity
-        };
+        let encoding_result = req
+            .headers()
+            .get(&ACCEPT_ENCODING)
+            .and_then(|val| val.to_str().ok())
+            .map(|enc| AcceptEncoding::try_parse(enc, self.encoding));
 
-        CompressResponse {
-            encoding,
-            fut: self.service.call(req),
-            _phantom: PhantomData,
+        match encoding_result {
+            // Missing header => fallback to identity
+            None => Either::left(CompressResponse {
+                encoding: ContentEncoding::Identity,
+                fut: self.service.call(req),
+                _phantom: PhantomData,
+            }),
+
+            // Valid encoding
+            Some(Ok(encoding)) => Either::left(CompressResponse {
+                encoding,
+                fut: self.service.call(req),
+                _phantom: PhantomData,
+            }),
+
+            // There is an HTTP header but we cannot match what client as asked for
+            Some(Err(_)) => {
+                let res = HttpResponse::with_body(
+                    StatusCode::NOT_ACCEPTABLE,
+                    SUPPORTED_ALGORITHM_NAMES.as_str(),
+                );
+                let enc = ContentEncoding::Identity;
+
+                Either::right(ok(req.into_response(res.map_body(move |head, body| {
+                    Encoder::response(enc, head, ResponseBody::Other(body.into()))
+                }))))
+            }
         }
     }
 }
@@ -114,7 +160,6 @@ where
 pub struct CompressResponse<S, B>
 where
     S: Service<ServiceRequest>,
-    B: MessageBody,
 {
     #[pin]
     fut: S::Future,
@@ -151,6 +196,7 @@ where
 
 struct AcceptEncoding {
     encoding: ContentEncoding,
+    // TODO: use Quality or QualityItem<ContentEncoding>
     quality: f64,
 }
 
@@ -177,26 +223,56 @@ impl PartialOrd for AcceptEncoding {
 
 impl PartialEq for AcceptEncoding {
     fn eq(&self, other: &AcceptEncoding) -> bool {
-        self.quality == other.quality
+        self.encoding == other.encoding && self.quality == other.quality
     }
 }
 
+/// Parse q-factor from quality strings.
+///
+/// If parse fail, then fallback to default value which is 1.
+/// More details available here: <https://developer.mozilla.org/en-US/docs/Glossary/Quality_values>
+fn parse_quality(parts: &[&str]) -> f64 {
+    for part in parts {
+        if part.trim().starts_with("q=") {
+            return part[2..].parse().unwrap_or(1.0);
+        }
+    }
+
+    1.0
+}
+
+#[derive(Debug, PartialEq, Eq)]
+enum AcceptEncodingError {
+    /// This error occurs when client only support compressed response and server do not have any
+    /// algorithm that match client accepted algorithms.
+    CompressionAlgorithmMismatch,
+}
+
 impl AcceptEncoding {
     fn new(tag: &str) -> Option<AcceptEncoding> {
         let parts: Vec<&str> = tag.split(';').collect();
         let encoding = match parts.len() {
             0 => return None,
-            _ => ContentEncoding::from(parts[0]),
-        };
-        let quality = match parts.len() {
-            1 => encoding.quality(),
-            _ => f64::from_str(parts[1]).unwrap_or(0.0),
+            _ => match ContentEncoding::try_from(parts[0]) {
+                Err(_) => return None,
+                Ok(x) => x,
+            },
         };
+
+        let quality = parse_quality(&parts[1..]);
+        if quality <= 0.0 || quality > 1.0 {
+            return None;
+        }
+
         Some(AcceptEncoding { encoding, quality })
     }
 
-    /// Parse a raw Accept-Encoding header value into an ordered list.
-    pub fn parse(raw: &str, encoding: ContentEncoding) -> ContentEncoding {
+    /// Parse a raw Accept-Encoding header value into an ordered list then return the best match
+    /// based on middleware configuration.
+    pub fn try_parse(
+        raw: &str,
+        encoding: ContentEncoding,
+    ) -> Result<ContentEncoding, AcceptEncodingError> {
         let mut encodings = raw
             .replace(' ', "")
             .split(',')
@@ -206,13 +282,90 @@ impl AcceptEncoding {
         encodings.sort();
 
         for enc in encodings {
-            if encoding == ContentEncoding::Auto {
-                return enc.encoding;
-            } else if encoding == enc.encoding {
-                return encoding;
+            if encoding == ContentEncoding::Auto || encoding == enc.encoding {
+                return Ok(enc.encoding);
             }
         }
 
-        ContentEncoding::Identity
+        // Special case if user cannot accept uncompressed data.
+        // See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept-Encoding
+        // TODO: account for whitespace
+        if raw.contains("*;q=0") || raw.contains("identity;q=0") {
+            return Err(AcceptEncodingError::CompressionAlgorithmMismatch);
+        }
+
+        Ok(ContentEncoding::Identity)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    macro_rules! assert_parse_eq {
+        ($raw:expr, $result:expr) => {
+            assert_eq!(
+                AcceptEncoding::try_parse($raw, ContentEncoding::Auto),
+                Ok($result)
+            );
+        };
+    }
+
+    macro_rules! assert_parse_fail {
+        ($raw:expr) => {
+            assert!(AcceptEncoding::try_parse($raw, ContentEncoding::Auto).is_err());
+        };
+    }
+
+    #[test]
+    fn test_parse_encoding() {
+        // Test simple case
+        assert_parse_eq!("br", ContentEncoding::Br);
+        assert_parse_eq!("gzip", ContentEncoding::Gzip);
+        assert_parse_eq!("deflate", ContentEncoding::Deflate);
+        assert_parse_eq!("zstd", ContentEncoding::Zstd);
+
+        // Test space, trim, missing values
+        assert_parse_eq!("br,,,,", ContentEncoding::Br);
+        assert_parse_eq!("gzip  ,   br,   zstd", ContentEncoding::Gzip);
+
+        // Test float number parsing
+        assert_parse_eq!("br;q=1  ,", ContentEncoding::Br);
+        assert_parse_eq!("br;q=1.0  ,   br", ContentEncoding::Br);
+
+        // Test wildcard
+        assert_parse_eq!("*", ContentEncoding::Identity);
+        assert_parse_eq!("*;q=1.0", ContentEncoding::Identity);
+    }
+
+    #[test]
+    fn test_parse_encoding_qfactor_ordering() {
+        assert_parse_eq!("gzip, br, zstd", ContentEncoding::Gzip);
+        assert_parse_eq!("zstd, br, gzip", ContentEncoding::Zstd);
+
+        assert_parse_eq!("gzip;q=0.4, br;q=0.6", ContentEncoding::Br);
+        assert_parse_eq!("gzip;q=0.8, br;q=0.4", ContentEncoding::Gzip);
+    }
+
+    #[test]
+    fn test_parse_encoding_qfactor_invalid() {
+        // Out of range
+        assert_parse_eq!("gzip;q=-5.0", ContentEncoding::Identity);
+        assert_parse_eq!("gzip;q=5.0", ContentEncoding::Identity);
+
+        // Disabled
+        assert_parse_eq!("gzip;q=0", ContentEncoding::Identity);
+    }
+
+    #[test]
+    fn test_parse_compression_required() {
+        // Check we fallback to identity if there is an unsupported compression algorithm
+        assert_parse_eq!("compress", ContentEncoding::Identity);
+
+        // User do not want any compression
+        assert_parse_fail!("compress, identity;q=0");
+        assert_parse_fail!("compress, identity;q=0.0");
+        assert_parse_fail!("compress, *;q=0");
+        assert_parse_fail!("compress, *;q=0.0");
     }
 }
diff --git a/tests/test_server.rs b/tests/test_server.rs
index afea39dd9..beb8ff0f5 100644
--- a/tests/test_server.rs
+++ b/tests/test_server.rs
@@ -1077,3 +1077,22 @@ async fn test_data_drop() {
 
     assert_eq!(num.load(Ordering::SeqCst), 0);
 }
+
+#[actix_rt::test]
+async fn test_accept_encoding_no_match() {
+    let srv = actix_test::start_with(actix_test::config().h1(), || {
+        App::new()
+            .wrap(Compress::default())
+            .service(web::resource("/").route(web::to(move || HttpResponse::Ok().finish())))
+    });
+
+    let response = srv
+        .get("/")
+        .append_header((ACCEPT_ENCODING, "compress, identity;q=0"))
+        .no_decompress()
+        .send()
+        .await
+        .unwrap();
+
+    assert_eq!(response.status().as_u16(), 406);
+}

From 93112644d3da17833ea03fc7856329ec2f35ba1c Mon Sep 17 00:00:00 2001
From: Rob Ede <robjtede@icloud.com>
Date: Wed, 1 Sep 2021 09:53:26 +0100
Subject: [PATCH 3/3] non exhaustive content encoding (#2377)

---
 Cargo.toml                                    |  2 +-
 actix-http/CHANGES.md                         |  3 ++
 actix-http/Cargo.toml                         |  2 +-
 actix-http/src/encoding/decoder.rs            |  3 +-
 .../src/header/shared/content_encoding.rs     | 17 ++++-------
 src/scope.rs                                  |  4 +--
 src/test.rs                                   |  2 +-
 src/types/form.rs                             |  2 +-
 src/types/json.rs                             | 30 ++++---------------
 src/types/query.rs                            | 30 ++++++++-----------
 10 files changed, 35 insertions(+), 60 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index cee401363..699717b4d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -99,7 +99,7 @@ regex = "1.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 serde_urlencoded = "0.7"
-smallvec = "1.6"
+smallvec = "1.6.1"
 socket2 = "0.4.0"
 time = { version = "0.2.23", default-features = false, features = ["std"] }
 url = "2.1"
diff --git a/actix-http/CHANGES.md b/actix-http/CHANGES.md
index f4efef54a..65206cf9a 100644
--- a/actix-http/CHANGES.md
+++ b/actix-http/CHANGES.md
@@ -2,6 +2,7 @@
 
 ## Unreleased - 2021-xx-xx
 ### Changed
+* `ContentEncoding` is now marked `#[non_exhaustive]`. [#2377]
 * Minimum supported Rust version (MSRV) is now 1.51.
 
 ### Fixed
@@ -12,12 +13,14 @@
 [#2364]: https://github.com/actix/actix-web/pull/2364
 [#2375]: https://github.com/actix/actix-web/pull/2375
 [#2344]: https://github.com/actix/actix-web/pull/2344
+[#2377]: https://github.com/actix/actix-web/pull/2377
 
 
 ## 3.0.0-beta.8 - 2021-08-09
 ### Fixed
 * Potential HTTP request smuggling vulnerabilities. [RUSTSEC-2021-0081](https://github.com/rustsec/advisory-db/pull/977)
 
+
 ## 3.0.0-beta.8 - 2021-06-26
 ### Changed
 * Change compression algorithm features flags. [#2250]
diff --git a/actix-http/Cargo.toml b/actix-http/Cargo.toml
index 68f980982..54505a215 100644
--- a/actix-http/Cargo.toml
+++ b/actix-http/Cargo.toml
@@ -73,7 +73,7 @@ rand = "0.8"
 regex = "1.3"
 serde = "1.0"
 sha-1 = "0.9"
-smallvec = "1.6"
+smallvec = "1.6.1"
 time = { version = "0.2.23", default-features = false, features = ["std"] }
 tokio = { version = "1.2", features = ["sync"] }
 
diff --git a/actix-http/src/encoding/decoder.rs b/actix-http/src/encoding/decoder.rs
index 81e97d916..c32983fc7 100644
--- a/actix-http/src/encoding/decoder.rs
+++ b/actix-http/src/encoding/decoder.rs
@@ -1,7 +1,6 @@
 //! Stream decoders.
 
 use std::{
-    convert::TryFrom,
     future::Future,
     io::{self, Write as _},
     pin::Pin,
@@ -81,7 +80,7 @@ where
         let encoding = headers
             .get(&CONTENT_ENCODING)
             .and_then(|val| val.to_str().ok())
-            .and_then(|x| ContentEncoding::try_from(x).ok())
+            .and_then(|x| x.parse().ok())
             .unwrap_or(ContentEncoding::Identity);
 
         Self::new(stream, encoding)
diff --git a/actix-http/src/header/shared/content_encoding.rs b/actix-http/src/header/shared/content_encoding.rs
index 375e8c2fa..1af109c06 100644
--- a/actix-http/src/header/shared/content_encoding.rs
+++ b/actix-http/src/header/shared/content_encoding.rs
@@ -1,5 +1,6 @@
-use std::{convert::TryFrom, error, fmt, str::FromStr};
+use std::{convert::TryFrom, str::FromStr};
 
+use derive_more::{Display, Error};
 use http::header::InvalidHeaderValue;
 
 use crate::{
@@ -11,19 +12,13 @@ use crate::{
 /// Error return when a content encoding is unknown.
 ///
 /// Example: 'compress'
-#[derive(Debug)]
+#[derive(Debug, Display, Error)]
+#[display(fmt = "unsupported content encoding")]
 pub struct ContentEncodingParseError;
 
-impl fmt::Display for ContentEncodingParseError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "Unsupported content encoding")
-    }
-}
-
-impl error::Error for ContentEncodingParseError {}
-
 /// Represents a supported content encoding.
-#[derive(Copy, Clone, PartialEq, Debug)]
+#[derive(Debug, Clone, Copy, PartialEq)]
+#[non_exhaustive]
 pub enum ContentEncoding {
     /// Automatically select encoding based on encoding negotiation.
     Auto,
diff --git a/src/scope.rs b/src/scope.rs
index b2edaedab..7d914f581 100644
--- a/src/scope.rs
+++ b/src/scope.rs
@@ -41,9 +41,9 @@ type HttpNewService = BoxServiceFactory<(), ServiceRequest, ServiceResponse, Err
 /// fn main() {
 ///     let app = App::new().service(
 ///         web::scope("/{project_id}/")
-///             .service(web::resource("/path1").to(|| async { HttpResponse::Ok() }))
+///             .service(web::resource("/path1").to(|| async { "OK" }))
 ///             .service(web::resource("/path2").route(web::get().to(|| HttpResponse::Ok())))
-///             .service(web::resource("/path3").route(web::head().to(|| HttpResponse::MethodNotAllowed())))
+///             .service(web::resource("/path3").route(web::head().to(HttpResponse::MethodNotAllowed)))
 ///     );
 /// }
 /// ```
diff --git a/src/test.rs b/src/test.rs
index 634826d19..34dd6f2d3 100644
--- a/src/test.rs
+++ b/src/test.rs
@@ -56,7 +56,7 @@ pub fn default_service(
 /// async fn test_init_service() {
 ///     let app = test::init_service(
 ///         App::new()
-///             .service(web::resource("/test").to(|| async { HttpResponse::Ok() }))
+///             .service(web::resource("/test").to(|| async { "OK" }))
 ///     ).await;
 ///
 ///     // Create request object
diff --git a/src/types/form.rs b/src/types/form.rs
index c81f73554..2ace0e063 100644
--- a/src/types/form.rs
+++ b/src/types/form.rs
@@ -30,7 +30,7 @@ use crate::{
 ///
 /// # Extractor
 /// To extract typed data from a request body, the inner type `T` must implement the
-/// [`serde::Deserialize`] trait.
+/// [`DeserializeOwned`] trait.
 ///
 /// Use [`FormConfig`] to configure extraction process.
 ///
diff --git a/src/types/json.rs b/src/types/json.rs
index ab9708c53..8c2f51a68 100644
--- a/src/types/json.rs
+++ b/src/types/json.rs
@@ -97,19 +97,13 @@ impl<T> ops::DerefMut for Json<T> {
     }
 }
 
-impl<T> fmt::Display for Json<T>
-where
-    T: fmt::Display,
-{
+impl<T: fmt::Display> fmt::Display for Json<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(&self.0, f)
     }
 }
 
-impl<T> Serialize for Json<T>
-where
-    T: Serialize,
-{
+impl<T: Serialize> Serialize for Json<T> {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
         S: serde::Serializer,
@@ -133,10 +127,7 @@ impl<T: Serialize> Responder for Json<T> {
 }
 
 /// See [here](#extractor) for example of usage as an extractor.
-impl<T> FromRequest for Json<T>
-where
-    T: DeserializeOwned + 'static,
-{
+impl<T: DeserializeOwned + 'static> FromRequest for Json<T> {
     type Error = Error;
     type Future = JsonExtractFut<T>;
     type Config = JsonConfig;
@@ -166,10 +157,7 @@ pub struct JsonExtractFut<T> {
     err_handler: JsonErrorHandler,
 }
 
-impl<T> Future for JsonExtractFut<T>
-where
-    T: DeserializeOwned + 'static,
-{
+impl<T: DeserializeOwned + 'static> Future for JsonExtractFut<T> {
     type Output = Result<Json<T>, Error>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
@@ -311,10 +299,7 @@ pub enum JsonBody<T> {
 
 impl<T> Unpin for JsonBody<T> {}
 
-impl<T> JsonBody<T>
-where
-    T: DeserializeOwned + 'static,
-{
+impl<T: DeserializeOwned> JsonBody<T> {
     /// Create a new future to decode a JSON request payload.
     #[allow(clippy::borrow_interior_mutable_const)]
     pub fn new(
@@ -395,10 +380,7 @@ where
     }
 }
 
-impl<T> Future for JsonBody<T>
-where
-    T: DeserializeOwned + 'static,
-{
+impl<T: DeserializeOwned + 'static> Future for JsonBody<T> {
     type Output = Result<T, JsonPayloadError>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
diff --git a/src/types/query.rs b/src/types/query.rs
index 1e6f1111f..73d08d092 100644
--- a/src/types/query.rs
+++ b/src/types/query.rs
@@ -3,14 +3,14 @@
 use std::{fmt, ops, sync::Arc};
 
 use actix_utils::future::{err, ok, Ready};
-use serde::de;
+use serde::de::DeserializeOwned;
 
 use crate::{dev::Payload, error::QueryPayloadError, Error, FromRequest, HttpRequest};
 
 /// Extract typed information from the request's query.
 ///
 /// To extract typed data from the URL query string, the inner type `T` must implement the
-/// [`serde::Deserialize`] trait.
+/// [`DeserializeOwned`] trait.
 ///
 /// Use [`QueryConfig`] to configure extraction process.
 ///
@@ -46,18 +46,18 @@ use crate::{dev::Payload, error::QueryPayloadError, Error, FromRequest, HttpRequ
 /// // To access the entire underlying query struct, use `.into_inner()`.
 /// #[get("/debug1")]
 /// async fn debug1(info: web::Query<AuthRequest>) -> String {
-///     dbg!("Authorization object={:?}", info.into_inner());
+///     dbg!("Authorization object = {:?}", info.into_inner());
 ///     "OK".to_string()
 /// }
 ///
-/// // Or use `.0`, which is equivalent to `.into_inner()`.
+/// // Or use destructuring, which is equivalent to `.into_inner()`.
 /// #[get("/debug2")]
-/// async fn debug2(info: web::Query<AuthRequest>) -> String {
-///     dbg!("Authorization object={:?}", info.0);
+/// async fn debug2(web::Query(info): web::Query<AuthRequest>) -> String {
+///     dbg!("Authorization object = {:?}", info);
 ///     "OK".to_string()
 /// }
 /// ```
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Query<T>(pub T);
 
 impl<T> Query<T> {
@@ -65,8 +65,10 @@ impl<T> Query<T> {
     pub fn into_inner(self) -> T {
         self.0
     }
+}
 
-    /// Deserialize `T` from a URL encoded query parameter string.
+impl<T: DeserializeOwned> Query<T> {
+    /// Deserialize a `T` from the URL encoded query parameter string.
     ///
     /// ```
     /// # use std::collections::HashMap;
@@ -76,10 +78,7 @@ impl<T> Query<T> {
     /// 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,
-    {
+    pub fn from_query(query_str: &str) -> Result<Self, QueryPayloadError> {
         serde_urlencoded::from_str::<T>(query_str)
             .map(Self)
             .map_err(QueryPayloadError::Deserialize)
@@ -107,10 +106,7 @@ impl<T: fmt::Display> fmt::Display for Query<T> {
 }
 
 /// See [here](#usage) for example of usage as an extractor.
-impl<T> FromRequest for Query<T>
-where
-    T: de::DeserializeOwned,
-{
+impl<T: DeserializeOwned> FromRequest for Query<T> {
     type Error = Error;
     type Future = Ready<Result<Self, Error>>;
     type Config = QueryConfig;
@@ -165,7 +161,7 @@ where
 /// let query_cfg = web::QueryConfig::default()
 ///     // use custom error handler
 ///     .error_handler(|err, req| {
-///         error::InternalError::from_response(err, HttpResponse::Conflict().into()).into()
+///         error::InternalError::from_response(err, HttpResponse::Conflict().finish()).into()
 ///     });
 ///
 /// App::new()