From 8c0cd9b9e90f932aeb57116f125d5435b0f12d63 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Wed, 10 Apr 2019 15:26:15 +0400
Subject: [PATCH] Prepare Media::Streaming::Reader to be shared.

---
 Telegram/SourceFiles/data/data_document.cpp   | 34 +++++---
 Telegram/SourceFiles/data/data_document.h     |  4 +-
 Telegram/SourceFiles/data/data_session.cpp    | 54 +++++++++++--
 Telegram/SourceFiles/data/data_session.h      | 12 +++
 .../media/player/media_player_instance.cpp    | 20 ++---
 .../media/player/media_player_instance.h      |  4 +-
 .../media/streaming/media_streaming_file.cpp  | 10 +--
 .../media/streaming/media_streaming_file.h    |  5 +-
 .../streaming/media_streaming_player.cpp      |  4 +-
 .../media/streaming/media_streaming_player.h  |  4 +-
 .../media/view/media_view_overlay_widget.cpp  | 10 +--
 .../SourceFiles/storage/file_download.cpp     | 33 ++++----
 Telegram/SourceFiles/storage/file_download.h  | 12 +--
 Telegram/SourceFiles/storage/file_upload.h    |  3 -
 .../storage/streamed_file_downloader.cpp      | 80 +++++++++++++++++++
 .../storage/streamed_file_downloader.h        | 60 ++++++++++++++
 Telegram/gyp/telegram_sources.txt             |  2 +
 17 files changed, 281 insertions(+), 70 deletions(-)
 create mode 100644 Telegram/SourceFiles/storage/streamed_file_downloader.cpp
 create mode 100644 Telegram/SourceFiles/storage/streamed_file_downloader.h

diff --git a/Telegram/SourceFiles/data/data_document.cpp b/Telegram/SourceFiles/data/data_document.cpp
index 2bbbd6c70..a5f1b73ab 100644
--- a/Telegram/SourceFiles/data/data_document.cpp
+++ b/Telegram/SourceFiles/data/data_document.cpp
@@ -17,7 +17,10 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "core/mime_type.h"
 #include "media/audio/media_audio.h"
 #include "media/player/media_player_instance.h"
+#include "media/streaming/media_streaming_loader_mtproto.h"
+#include "media/streaming/media_streaming_loader_local.h"
 #include "storage/localstorage.h"
+#include "storage/streamed_file_downloader.h"
 #include "platform/platform_specific.h"
 #include "history/history.h"
 #include "history/history_item.h"
@@ -29,8 +32,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "mainwindow.h"
 #include "core/application.h"
 #include "lottie/lottie_animation.h"
-#include "media/streaming/media_streaming_loader_mtproto.h"
-#include "media/streaming/media_streaming_loader_local.h"
 
 namespace {
 
@@ -736,7 +737,7 @@ void DocumentData::automaticLoadSettingsChanged() {
 bool DocumentData::loaded(FilePathResolve resolve) const {
 	if (loading() && _loader->finished()) {
 		if (_loader->cancelled()) {
-			destroyLoader(CancelledMtpFileLoader);
+			destroyLoader(CancelledFileLoader);
 		} else {
 			auto that = const_cast<DocumentData*>(this);
 			that->_location = FileLocation(_loader->fileName());
@@ -768,7 +769,7 @@ bool DocumentData::loaded(FilePathResolve resolve) const {
 	return !data().isEmpty() || !filepath(resolve).isEmpty();
 }
 
-void DocumentData::destroyLoader(mtpFileLoader *newValue) const {
+void DocumentData::destroyLoader(FileLoader *newValue) const {
 	const auto loader = std::exchange(_loader, newValue);
 	if (cancelled()) {
 		loader->cancel();
@@ -803,7 +804,7 @@ float64 DocumentData::progress() const {
 	return loading() ? _loader->currentProgress() : (loaded() ? 1. : 0.);
 }
 
-int32 DocumentData::loadOffset() const {
+int DocumentData::loadOffset() const {
 	return loading() ? _loader->currentOffset() : 0;
 }
 
@@ -854,7 +855,7 @@ void DocumentData::save(
 	}
 	if (_loader) {
 		if (!_loader->setFileName(toFile)) {
-			cancel(); // changes _actionOnLoad
+			cancel();
 			_loader = nullptr;
 		}
 	}
@@ -865,7 +866,22 @@ void DocumentData::save(
 		}
 	} else {
 		status = FileReady;
-		if (hasWebLocation()) {
+/*		if (auto reader = owner().documentStreamedReader(this, origin)) {
+			_loader = new Storage::StreamedFileDownloader(
+				id,
+				origin,
+				(saveToCache()
+					? std::make_optional(Data::DocumentCacheKey(_dc, id))
+					: std::nullopt),
+				std::move(reader),
+				toFile,
+				size,
+				locationType(),
+				(saveToCache() ? LoadToCacheAsWell : LoadToFileOnly),
+				fromCloud,
+				autoLoading,
+				cacheTag());
+		} else */if (hasWebLocation()) {
 			_loader = new mtpFileLoader(
 				_urlLocation,
 				size,
@@ -913,13 +929,13 @@ void DocumentData::cancel() {
 		return;
 	}
 
-	destroyLoader(CancelledMtpFileLoader);
+	destroyLoader(CancelledFileLoader);
 	_owner->notifyDocumentLayoutChanged(this);
 	App::main()->documentLoadProgress(this);
 }
 
 bool DocumentData::cancelled() const {
-	return (_loader == CancelledMtpFileLoader);
+	return (_loader == CancelledFileLoader);
 }
 
 VoiceWaveform documentWaveformDecode(const QByteArray &encoded5bit) {
diff --git a/Telegram/SourceFiles/data/data_document.h b/Telegram/SourceFiles/data/data_document.h
index 6ea24f362..e8836d92d 100644
--- a/Telegram/SourceFiles/data/data_document.h
+++ b/Telegram/SourceFiles/data/data_document.h
@@ -112,7 +112,7 @@ public:
 	void cancel();
 	[[nodiscard]] bool cancelled() const;
 	[[nodiscard]] float64 progress() const;
-	[[nodiscard]] int32 loadOffset() const;
+	[[nodiscard]] int loadOffset() const;
 	[[nodiscard]] bool uploading() const;
 
 	void setWaitingForAlbum();
@@ -247,7 +247,7 @@ private:
 	void validateGoodThumbnail();
 	void setMaybeSupportsStreaming(bool supports);
 
-	void destroyLoader(mtpFileLoader *newValue = nullptr) const;
+	void destroyLoader(FileLoader *newValue = nullptr) const;
 
 	[[nodiscard]] bool thumbnailEnoughForSticker() const;
 
diff --git a/Telegram/SourceFiles/data/data_session.cpp b/Telegram/SourceFiles/data/data_session.cpp
index e5a885028..f212d375d 100644
--- a/Telegram/SourceFiles/data/data_session.cpp
+++ b/Telegram/SourceFiles/data/data_session.cpp
@@ -12,9 +12,9 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "apiwrap.h"
 #include "mainwidget.h"
 #include "core/application.h"
-#include "core/crash_reports.h" // for CrashReports::SetAnnotation
+#include "core/crash_reports.h" // CrashReports::SetAnnotation
 #include "ui/image/image.h"
-#include "ui/image/image_source.h" // for Images::LocalFileSource
+#include "ui/image/image_source.h" // Images::LocalFileSource
 #include "export/export_controller.h"
 #include "export/view/export_view_panel_controller.h"
 #include "window/notifications_manager.h"
@@ -25,11 +25,13 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "inline_bots/inline_bot_layout_item.h"
 #include "storage/localstorage.h"
 #include "storage/storage_encrypted_file.h"
-#include "media/player/media_player_instance.h" // for instance()->play().
+#include "media/player/media_player_instance.h" // instance()->play()
+#include "media/streaming/media_streaming_loader.h" // unique_ptr<Loader>
+#include "media/streaming/media_streaming_reader.h" // make_shared<Reader>
 #include "boxes/abstract_box.h"
 #include "passport/passport_form_controller.h"
 #include "window/themes/window_theme.h"
-#include "lang/lang_keys.h" // for lang(lng_deleted) in user name.
+#include "lang/lang_keys.h" // lang(lng_deleted) in user name
 #include "data/data_media_types.h"
 #include "data/data_folder.h"
 #include "data/data_channel.h"
@@ -41,7 +43,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_web_page.h"
 #include "data/data_game.h"
 #include "data/data_poll.h"
-#include "styles/style_boxes.h" // for st::backgroundSize
+#include "styles/style_boxes.h" // st::backgroundSize
 
 namespace Data {
 namespace {
@@ -150,6 +152,26 @@ rpl::producer<int> PinnedDialogsCountMaxValue() {
 	});
 }
 
+bool PruneDestroyedAndSet(
+		base::flat_map<
+			not_null<DocumentData*>,
+			std::weak_ptr<::Media::Streaming::Reader>> &readers,
+		not_null<DocumentData*> document,
+		const std::shared_ptr<::Media::Streaming::Reader> &reader) {
+	auto result = false;
+	for (auto i = begin(readers); i != end(readers);) {
+		if (i->first == document) {
+			(i++)->second = reader;
+			result = true;
+		} else if (i->second.lock() != nullptr) {
+			++i;
+		} else {
+			i = readers.erase(i);
+		}
+	}
+	return result;
+}
+
 } // namespace
 
 Session::Session(not_null<AuthSession*> session)
@@ -1067,6 +1089,28 @@ void Session::requestDocumentViewRepaint(
 	}
 }
 
+std::shared_ptr<::Media::Streaming::Reader> Session::documentStreamedReader(
+		not_null<DocumentData*> document,
+		FileOrigin origin) {
+	const auto i = _streamedReaders.find(document);
+	if (i != end(_streamedReaders)) {
+		if (auto result = i->second.lock()) {
+			return result;
+		}
+	}
+	auto loader = document->createStreamingLoader(origin);
+	if (!loader) {
+		return nullptr;
+	}
+	auto result = std::make_shared<::Media::Streaming::Reader>(
+		this,
+		std::move(loader));
+	if (!PruneDestroyedAndSet(_streamedReaders, document, result)) {
+		_streamedReaders.emplace(document, result);
+	}
+	return result;
+}
+
 void Session::requestPollViewRepaint(not_null<const PollData*> poll) {
 	if (const auto i = _pollViews.find(poll); i != _pollViews.end()) {
 		for (const auto view : i->second) {
diff --git a/Telegram/SourceFiles/data/data_session.h b/Telegram/SourceFiles/data/data_session.h
index 805a22b39..23dd8d002 100644
--- a/Telegram/SourceFiles/data/data_session.h
+++ b/Telegram/SourceFiles/data/data_session.h
@@ -39,6 +39,9 @@ namespace Media {
 namespace Clip {
 class Reader;
 } // namespace Clip
+namespace Streaming {
+class Reader;
+} // namespace Streaming
 } // namespace Media
 
 namespace Export {
@@ -397,6 +400,10 @@ public:
 	void markMediaRead(not_null<const DocumentData*> document);
 	void requestPollViewRepaint(not_null<const PollData*> poll);
 
+	std::shared_ptr<::Media::Streaming::Reader> documentStreamedReader(
+		not_null<DocumentData*> document,
+		FileOrigin origin);
+
 	HistoryItem *addNewMessage(const MTPMessage &data, NewMessageType type);
 
 	struct SendActionAnimationUpdate {
@@ -915,8 +922,13 @@ private:
 	base::flat_set<not_null<GameData*>> _gamesUpdated;
 	base::flat_set<not_null<PollData*>> _pollsUpdated;
 
+	base::flat_map<
+		not_null<DocumentData*>,
+		std::weak_ptr<::Media::Streaming::Reader>> _streamedReaders;
+
 	base::flat_map<FolderId, std::unique_ptr<Folder>> _folders;
 	//rpl::variable<FeedId> _defaultFeedId = FeedId(); // #feed
+
 	Groups _groups;
 	std::unordered_map<
 		not_null<const HistoryItem*>,
diff --git a/Telegram/SourceFiles/media/player/media_player_instance.cpp b/Telegram/SourceFiles/media/player/media_player_instance.cpp
index 6fdafcf51..2a243e6c5 100644
--- a/Telegram/SourceFiles/media/player/media_player_instance.cpp
+++ b/Telegram/SourceFiles/media/player/media_player_instance.cpp
@@ -12,7 +12,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "media/audio/media_audio.h"
 #include "media/audio/media_audio_capture.h"
 #include "media/streaming/media_streaming_player.h"
-#include "media/streaming/media_streaming_loader.h"
+#include "media/streaming/media_streaming_reader.h"
 #include "media/view/media_view_playback_progress.h"
 #include "calls/calls_instance.h"
 #include "history/history.h"
@@ -59,7 +59,7 @@ struct Instance::Streamed {
 	Streamed(
 		AudioMsgId id,
 		not_null<::Data::Session*> owner,
-		std::unique_ptr<Streaming::Loader> loader);
+		std::shared_ptr<Streaming::Reader> reader);
 
 	AudioMsgId id;
 	Streaming::Player player;
@@ -71,9 +71,9 @@ struct Instance::Streamed {
 Instance::Streamed::Streamed(
 	AudioMsgId id,
 	not_null<::Data::Session*> owner,
-	std::unique_ptr<Streaming::Loader> loader)
+	std::shared_ptr<Streaming::Reader> reader)
 : id(id)
-, player(owner, std::move(loader)) {
+, player(owner, std::move(reader)) {
 }
 
 Instance::Data::Data(AudioMsgId::Type type, SharedMediaType overview)
@@ -355,11 +355,13 @@ void Instance::play(const AudioMsgId &audioId) {
 	if (document->isAudioFile()
 		|| document->isVoiceMessage()
 		|| document->isVideoMessage()) {
-		auto loader = document->createStreamingLoader(audioId.contextId());
-		if (!loader) {
+		auto reader = document->owner().documentStreamedReader(
+			document,
+			audioId.contextId());
+		if (!reader) {
 			return;
 		}
-		playStreamed(audioId, std::move(loader));
+		playStreamed(audioId, std::move(reader));
 	}
 	if (document->isVoiceMessage() || document->isVideoMessage()) {
 		document->owner().markMediaRead(document);
@@ -378,7 +380,7 @@ void Instance::playPause(const AudioMsgId &audioId) {
 
 void Instance::playStreamed(
 		const AudioMsgId &audioId,
-		std::unique_ptr<Streaming::Loader> loader) {
+		std::shared_ptr<Streaming::Reader> reader) {
 	Expects(audioId.audio() != nullptr);
 
 	const auto data = getData(audioId.type());
@@ -388,7 +390,7 @@ void Instance::playStreamed(
 	data->streamed = std::make_unique<Streamed>(
 		audioId,
 		&audioId.audio()->owner(),
-		std::move(loader));
+		std::move(reader));
 
 	data->streamed->player.updates(
 	) | rpl::start_with_next_error([=](Streaming::Update &&update) {
diff --git a/Telegram/SourceFiles/media/player/media_player_instance.h b/Telegram/SourceFiles/media/player/media_player_instance.h
index 6441ac2c6..c20a25b26 100644
--- a/Telegram/SourceFiles/media/player/media_player_instance.h
+++ b/Telegram/SourceFiles/media/player/media_player_instance.h
@@ -26,7 +26,7 @@ class PlaybackProgress;
 namespace Media {
 namespace Streaming {
 class Player;
-class Loader;
+class Reader;
 struct PlaybackOptions;
 struct Update;
 enum class Error;
@@ -195,7 +195,7 @@ private:
 	void setupShortcuts();
 	void playStreamed(
 		const AudioMsgId &audioId,
-		std::unique_ptr<Streaming::Loader> loader);
+		std::shared_ptr<Streaming::Reader> reader);
 	Streaming::PlaybackOptions streamingOptions(
 		const AudioMsgId &audioId,
 		crl::time position = 0);
diff --git a/Telegram/SourceFiles/media/streaming/media_streaming_file.cpp b/Telegram/SourceFiles/media/streaming/media_streaming_file.cpp
index daf324522..813df6137 100644
--- a/Telegram/SourceFiles/media/streaming/media_streaming_file.cpp
+++ b/Telegram/SourceFiles/media/streaming/media_streaming_file.cpp
@@ -327,14 +327,14 @@ bool File::Context::finished() const {
 
 File::File(
 	not_null<Data::Session*> owner,
-	std::unique_ptr<Loader> loader)
-: _reader(owner, std::move(loader)) {
+	std::shared_ptr<Reader> reader)
+: _reader(std::move(reader)) {
 }
 
 void File::start(not_null<FileDelegate*> delegate, crl::time position) {
 	stop();
 
-	_context.emplace(delegate, &_reader);
+	_context.emplace(delegate, _reader.get());
 	_thread = std::thread([=, context = &*_context] {
 		context->start(position);
 		while (!context->finished()) {
@@ -354,12 +354,12 @@ void File::stop() {
 		_context->interrupt();
 		_thread.join();
 	}
-	_reader.stop();
+	_reader->stop();
 	_context.reset();
 }
 
 bool File::isRemoteLoader() const {
-	return _reader.isRemoteLoader();
+	return _reader->isRemoteLoader();
 }
 
 File::~File() {
diff --git a/Telegram/SourceFiles/media/streaming/media_streaming_file.h b/Telegram/SourceFiles/media/streaming/media_streaming_file.h
index 5faf2473f..31523add7 100644
--- a/Telegram/SourceFiles/media/streaming/media_streaming_file.h
+++ b/Telegram/SourceFiles/media/streaming/media_streaming_file.h
@@ -22,12 +22,11 @@ class Session;
 namespace Media {
 namespace Streaming {
 
-class Loader;
 class FileDelegate;
 
 class File final {
 public:
-	File(not_null<Data::Session*> owner, std::unique_ptr<Loader> loader);
+	File(not_null<Data::Session*> owner, std::shared_ptr<Reader> reader);
 
 	File(const File &other) = delete;
 	File &operator=(const File &other) = delete;
@@ -98,7 +97,7 @@ private:
 	};
 
 	std::optional<Context> _context;
-	Reader _reader;
+	std::shared_ptr<Reader> _reader;
 	std::thread _thread;
 
 };
diff --git a/Telegram/SourceFiles/media/streaming/media_streaming_player.cpp b/Telegram/SourceFiles/media/streaming/media_streaming_player.cpp
index 5bfa16010..954060d17 100644
--- a/Telegram/SourceFiles/media/streaming/media_streaming_player.cpp
+++ b/Telegram/SourceFiles/media/streaming/media_streaming_player.cpp
@@ -78,8 +78,8 @@ void SaveValidStartInformation(Information &to, Information &&from) {
 
 Player::Player(
 	not_null<Data::Session*> owner,
-	std::unique_ptr<Loader> loader)
-: _file(std::make_unique<File>(owner, std::move(loader)))
+	std::shared_ptr<Reader> reader)
+: _file(std::make_unique<File>(owner, std::move(reader)))
 , _remoteLoader(_file->isRemoteLoader())
 , _renderFrameTimer([=] { checkNextFrameRender(); }) {
 }
diff --git a/Telegram/SourceFiles/media/streaming/media_streaming_player.h b/Telegram/SourceFiles/media/streaming/media_streaming_player.h
index e75985c38..5cbc06c93 100644
--- a/Telegram/SourceFiles/media/streaming/media_streaming_player.h
+++ b/Telegram/SourceFiles/media/streaming/media_streaming_player.h
@@ -25,7 +25,7 @@ struct TrackState;
 namespace Media {
 namespace Streaming {
 
-class Loader;
+class Reader;
 class File;
 class AudioTrack;
 class VideoTrack;
@@ -33,7 +33,7 @@ class VideoTrack;
 class Player final : private FileDelegate {
 public:
 	// Public interfaces is used from the main thread.
-	Player(not_null<Data::Session*> owner, std::unique_ptr<Loader> loader);
+	Player(not_null<Data::Session*> owner, std::shared_ptr<Reader> reader);
 
 	// Because we remember 'this' in calls to crl::on_main.
 	Player(const Player &other) = delete;
diff --git a/Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp b/Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp
index ff47b971d..818fb05fd 100644
--- a/Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp
+++ b/Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp
@@ -24,7 +24,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "media/view/media_view_playback_controls.h"
 #include "media/view/media_view_group_thumbs.h"
 #include "media/streaming/media_streaming_player.h"
-#include "media/streaming/media_streaming_loader.h"
+#include "media/streaming/media_streaming_reader.h"
 #include "media/player/media_player_instance.h"
 #include "lottie/lottie_animation.h"
 #include "history/history.h"
@@ -172,7 +172,7 @@ struct OverlayWidget::Streamed {
 	template <typename Callback>
 	Streamed(
 		not_null<Data::Session*> owner,
-		std::unique_ptr<Streaming::Loader> loader,
+		std::shared_ptr<Streaming::Reader> reader,
 		QWidget *controlsParent,
 		not_null<PlaybackControls::Delegate*> controlsDelegate,
 		Callback &&loadingCallback);
@@ -201,11 +201,11 @@ struct OverlayWidget::LottieFile {
 template <typename Callback>
 OverlayWidget::Streamed::Streamed(
 	not_null<Data::Session*> owner,
-	std::unique_ptr<Streaming::Loader> loader,
+	std::shared_ptr<Streaming::Reader> reader,
 	QWidget *controlsParent,
 	not_null<PlaybackControls::Delegate*> controlsDelegate,
 	Callback &&loadingCallback)
-: player(owner, std::move(loader))
+: player(owner, std::move(reader))
 , controls(controlsParent, controlsDelegate)
 , radial(
 	std::forward<Callback>(loadingCallback),
@@ -2042,7 +2042,7 @@ void OverlayWidget::streamingReady(Streaming::Information &&info) {
 void OverlayWidget::createStreamingObjects() {
 	_streamed = std::make_unique<Streamed>(
 		&_doc->owner(),
-		_doc->createStreamingLoader(fileOrigin()),
+		_doc->owner().documentStreamedReader(_doc, fileOrigin()),
 		this,
 		static_cast<PlaybackControls::Delegate*>(this),
 		[=] { waitingAnimationCallback(); });
diff --git a/Telegram/SourceFiles/storage/file_download.cpp b/Telegram/SourceFiles/storage/file_download.cpp
index 5f4e8695c..10ef27eaa 100644
--- a/Telegram/SourceFiles/storage/file_download.cpp
+++ b/Telegram/SourceFiles/storage/file_download.cpp
@@ -229,7 +229,7 @@ float64 FileLoader::currentProgress() const {
 	return snap(float64(currentOffset()) / fullSize(), 0., 1.);
 }
 
-int32 FileLoader::fullSize() const {
+int FileLoader::fullSize() const {
 	return _size;
 }
 
@@ -281,7 +281,7 @@ void FileLoader::removeFromQueue() {
 	if (_queue->start == this) {
 		_queue->start = _next;
 	}
-	_next = _prev = 0;
+	_next = _prev = nullptr;
 	_inQueue = false;
 }
 
@@ -331,7 +331,7 @@ void FileLoader::start(bool loadFirst, bool prior) {
 	}
 
 	auto currentPriority = _downloader->currentPriority();
-	FileLoader *before = 0, *after = 0;
+	FileLoader *before = nullptr, *after = nullptr;
 	if (prior) {
 		if (_inQueue && _priority == currentPriority) {
 			if (loadFirst) {
@@ -491,7 +491,7 @@ void FileLoader::cancel() {
 }
 
 void FileLoader::cancel(bool fail) {
-	bool started = currentOffset(true) > 0;
+	const auto started = (currentOffset() > 0);
 	cancelRequests();
 	_cancelled = true;
 	_finished = true;
@@ -598,9 +598,8 @@ mtpFileLoader::mtpFileLoader(
 	_queue = &i.value();
 }
 
-int32 mtpFileLoader::currentOffset(bool includeSkipped) const {
-	return (_fileIsOpen ? _file.size() : _data.size())
-		- (includeSkipped ? 0 : _skippedBytes);
+int mtpFileLoader::currentOffset() const {
+	return (_fileIsOpen ? _file.size() : _data.size()) - _skippedBytes;
 }
 
 Data::FileOrigin mtpFileLoader::fileOrigin() const {
@@ -1218,7 +1217,7 @@ bool webFileLoader::loadPart() {
 	return false;
 }
 
-int32 webFileLoader::currentOffset(bool includeSkipped) const {
+int webFileLoader::currentOffset() const {
 	return _already;
 }
 
@@ -1359,8 +1358,8 @@ void stopWebLoadManager() {
 		delete _webLoadManager;
 		delete _webLoadMainManager;
 		delete _webLoadThread;
-		_webLoadThread = 0;
-		_webLoadMainManager = 0;
+		_webLoadThread = nullptr;
+		_webLoadMainManager = nullptr;
 		_webLoadManager = FinishedWebLoadManager;
 	}
 }
@@ -1515,9 +1514,9 @@ void WebLoadManager::onMeta() {
 	const auto loader = j.value();
 
 	const auto pairs = reply->rawHeaderPairs();
-	for (auto i = pairs.begin(), e = pairs.end(); i != e; ++i) {
-		if (QString::fromUtf8(i->first).toLower() == "content-range") {
-			const auto m = QRegularExpression(qsl("/(\\d+)([^\\d]|$)")).match(QString::fromUtf8(i->second));
+	for (const auto &pair : pairs) {
+		if (QString::fromUtf8(pair.first).toLower() == "content-range") {
+			const auto m = QRegularExpression(qsl("/(\\d+)([^\\d]|$)")).match(QString::fromUtf8(pair.second));
 			if (m.hasMatch()) {
 				loader->setProgress(qMax(qint64(loader->data().size()), loader->already()), m.captured(1).toLongLong());
 				if (!handleReplyResult(loader, WebReplyProcessProgress)) {
@@ -1598,19 +1597,19 @@ void WebLoadManager::finish() {
 
 void WebLoadManager::clear() {
 	QMutexLocker lock(&_loaderPointersMutex);
-	for (LoaderPointers::iterator i = _loaderPointers.begin(), e = _loaderPointers.end(); i != e; ++i) {
+	for (auto i = _loaderPointers.begin(), e = _loaderPointers.end(); i != e; ++i) {
 		if (i.value()) {
-			i.key()->_private = 0;
+			i.key()->_private = nullptr;
 		}
 	}
 	_loaderPointers.clear();
 
-	for_const (webFileLoaderPrivate *loader, _loaders) {
+	for (const auto loader : _loaders) {
 		delete loader;
 	}
 	_loaders.clear();
 
-	for (Replies::iterator i = _replies.begin(), e = _replies.end(); i != e; ++i) {
+	for (auto i = _replies.begin(), e = _replies.end(); i != e; ++i) {
 		delete i.key();
 	}
 	_replies.clear();
diff --git a/Telegram/SourceFiles/storage/file_download.h b/Telegram/SourceFiles/storage/file_download.h
index aeee1755b..9a1c792f2 100644
--- a/Telegram/SourceFiles/storage/file_download.h
+++ b/Telegram/SourceFiles/storage/file_download.h
@@ -106,8 +106,8 @@ public:
 	}
 	virtual Data::FileOrigin fileOrigin() const;
 	float64 currentProgress() const;
-	virtual int32 currentOffset(bool includeSkipped = false) const = 0;
-	int32 fullSize() const;
+	virtual int currentOffset() const = 0;
+	int fullSize() const;
 
 	bool setFileName(const QString &filename); // set filename for loaders to cache
 	void permitLoadFromCloud();
@@ -191,8 +191,8 @@ protected:
 
 	QByteArray _data;
 
-	int32 _size;
-	LocationType _locationType;
+	int _size = 0;
+	LocationType _locationType = LocationType();
 
 	base::binary_guard _localLoading;
 	mutable QByteArray _imageFormat;
@@ -227,7 +227,7 @@ public:
 		bool autoLoading,
 		uint8 cacheTag);
 
-	int32 currentOffset(bool includeSkipped = false) const override;
+	int currentOffset() const override;
 	Data::FileOrigin fileOrigin() const override;
 
 	uint64 objId() const override;
@@ -325,7 +325,7 @@ public:
 		bool autoLoading,
 		uint8 cacheTag);
 
-	int32 currentOffset(bool includeSkipped = false) const override;
+	int currentOffset() const override;
 
 	void onProgress(qint64 already, qint64 size);
 	void onFinished(const QByteArray &data);
diff --git a/Telegram/SourceFiles/storage/file_upload.h b/Telegram/SourceFiles/storage/file_upload.h
index 6b05b7dd6..a02f7aa83 100644
--- a/Telegram/SourceFiles/storage/file_upload.h
+++ b/Telegram/SourceFiles/storage/file_upload.h
@@ -59,9 +59,6 @@ public:
 		const FullMsgId &msgId,
 		const std::shared_ptr<FileLoadResult> &file);
 
-	int32 currentOffset(const FullMsgId &msgId) const; // -1 means file not found
-	int32 fullSize(const FullMsgId &msgId) const;
-
 	void cancel(const FullMsgId &msgId);
 	void pause(const FullMsgId &msgId);
 	void confirm(const FullMsgId &msgId);
diff --git a/Telegram/SourceFiles/storage/streamed_file_downloader.cpp b/Telegram/SourceFiles/storage/streamed_file_downloader.cpp
new file mode 100644
index 000000000..f5d4024ed
--- /dev/null
+++ b/Telegram/SourceFiles/storage/streamed_file_downloader.cpp
@@ -0,0 +1,80 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#include "storage/streamed_file_downloader.h"
+
+#include "media/streaming/media_streaming_loader.h"
+#include "media/streaming/media_streaming_reader.h"
+
+namespace Storage {
+namespace {
+
+constexpr auto kPartSize = Media::Streaming::Loader::kPartSize;
+
+} // namespace
+
+StreamedFileDownloader::StreamedFileDownloader(
+	uint64 objectId,
+	Data::FileOrigin origin,
+	std::optional<Cache::Key> cacheKey,
+	std::shared_ptr<Media::Streaming::Reader> reader,
+
+	// For FileLoader
+	const QString &toFile,
+	int32 size,
+	LocationType locationType,
+	LoadToCacheSetting toCache,
+	LoadFromCloudSetting fromCloud,
+	bool autoLoading,
+	uint8 cacheTag)
+: FileLoader(
+	toFile,
+	size,
+	locationType,
+	toCache,
+	fromCloud,
+	autoLoading,
+	cacheTag)
+, _objectId(objectId)
+, _origin(origin)
+, _cacheKey(cacheKey)
+, _reader(std::move(reader)) {
+	_partIsSaved.resize((size + kPartSize - 1) / kPartSize, false);
+}
+
+StreamedFileDownloader::~StreamedFileDownloader() {
+	stop();
+}
+
+uint64 StreamedFileDownloader::objId() const {
+	return _objectId;
+}
+
+Data::FileOrigin StreamedFileDownloader::fileOrigin() const {
+	return _origin;
+}
+
+int StreamedFileDownloader::currentOffset() const {
+	return 0;
+}
+
+void StreamedFileDownloader::stop() {
+	cancelRequests();
+}
+
+std::optional<Storage::Cache::Key> StreamedFileDownloader::cacheKey() const {
+	return _cacheKey;
+}
+
+void StreamedFileDownloader::cancelRequests() {
+}
+
+bool StreamedFileDownloader::loadPart() {
+	return false;
+}
+
+} // namespace Storage
diff --git a/Telegram/SourceFiles/storage/streamed_file_downloader.h b/Telegram/SourceFiles/storage/streamed_file_downloader.h
new file mode 100644
index 000000000..9e5d1f1cf
--- /dev/null
+++ b/Telegram/SourceFiles/storage/streamed_file_downloader.h
@@ -0,0 +1,60 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+#include "storage/file_download.h"
+#include "storage/cache/storage_cache_types.h"
+
+namespace Media {
+namespace Streaming {
+class Reader;
+} // namespace Streaming
+} // namespace Media
+
+namespace Storage {
+
+class StreamedFileDownloader final : public FileLoader {
+public:
+	StreamedFileDownloader(
+		uint64 objectId,
+		Data::FileOrigin origin,
+		std::optional<Cache::Key> cacheKey,
+		std::shared_ptr<Media::Streaming::Reader> reader,
+
+		// For FileLoader
+		const QString &toFile,
+		int32 size,
+		LocationType locationType,
+		LoadToCacheSetting toCache,
+		LoadFromCloudSetting fromCloud,
+		bool autoLoading,
+		uint8 cacheTag);
+	~StreamedFileDownloader();
+
+	uint64 objId() const override;
+	Data::FileOrigin fileOrigin() const override;
+	int currentOffset() const override;
+	void stop() override;
+
+private:
+	std::optional<Storage::Cache::Key> cacheKey() const override;
+	void cancelRequests() override;
+	bool loadPart() override;
+
+private:
+	uint64 _objectId = 0;
+	Data::FileOrigin _origin;
+	std::optional<Cache::Key> _cacheKey;
+	std::shared_ptr<Media::Streaming::Reader> _reader;
+
+	std::vector<bool> _partIsSaved; // vector<bool> :D
+	int _nextPartIndex = 0;
+
+};
+
+} // namespace Storage
diff --git a/Telegram/gyp/telegram_sources.txt b/Telegram/gyp/telegram_sources.txt
index 38f648d59..3a7a6fcc4 100644
--- a/Telegram/gyp/telegram_sources.txt
+++ b/Telegram/gyp/telegram_sources.txt
@@ -683,6 +683,8 @@
 <(src_loc)/storage/storage_sparse_ids_list.h
 <(src_loc)/storage/storage_user_photos.cpp
 <(src_loc)/storage/storage_user_photos.h
+<(src_loc)/storage/streamed_file_downloader.cpp
+<(src_loc)/storage/streamed_file_downloader.h
 <(src_loc)/support/support_autocomplete.cpp
 <(src_loc)/support/support_autocomplete.h
 <(src_loc)/support/support_common.cpp