Optimize updates subscription in topics.

Telegram/SourceFiles/data/data_forum_topic.cpp

@@ -151,7 +151,7 @@ ForumTopic::ForumTopic(not_null<Forum*> forum, MsgId rootId)
 : Thread(&forum->history()->owner(), Type::ForumTopic)
 , _forum(forum)
 , _list(_forum->topicsList())
-, _replies(std::make_shared<RepliesList>(history(), rootId))
+, _replies(std::make_shared<RepliesList>(history(), rootId, this))
 , _sendActionPainter(owner().sendActionManager().repliesPainter(
 	history(),
 	rootId))

Telegram/SourceFiles/data/data_replies_list.cpp

@@ -60,38 +60,24 @@ struct RepliesList::Viewer {
 	bool scheduled = false;
 };
 
-RepliesList::RepliesList(not_null<History*> history, MsgId rootId)
+RepliesList::RepliesList(
+	not_null<History*> history,
+	MsgId rootId,
+	ForumTopic *owningTopic)
 : _history(history)
+, _owningTopic(owningTopic)
 , _rootId(rootId)
 , _creating(IsCreating(history, rootId))
 , _readRequestTimer([=] { sendReadTillRequest(); }) {
-	_history->owner().repliesReadTillUpdates(
-	) | rpl::filter([=](const RepliesReadTillUpdate &update) {
-		return (update.id.msg == _rootId)
-			&& (update.id.peer == _history->peer->id);
-	}) | rpl::start_with_next([=](const RepliesReadTillUpdate &update) {
-		if (update.out) {
-			setOutboxReadTill(update.readTillId);
-		} else if (update.readTillId >= _inboxReadTillId) {
-			setInboxReadTill(
-				update.readTillId,
-				computeUnreadCountLocally(update.readTillId));
-		}
-	}, _lifetime);
-
-	_history->session().changes().messageUpdates(
-		MessageUpdate::Flag::NewAdded
-		| MessageUpdate::Flag::NewMaybeAdded
-		| MessageUpdate::Flag::ReplyToTopAdded
-		| MessageUpdate::Flag::Destroyed
-	) | rpl::filter([=](const MessageUpdate &update) {
-		return applyUpdate(update);
-	}) | rpl::to_empty | rpl::start_to_stream(_instantChanges, _lifetime);
-
-	_history->owner().channelDifferenceTooLong(
-	) | rpl::filter([=](not_null<ChannelData*> channel) {
-		return applyDifferenceTooLong(channel);
-	}) | rpl::to_empty | rpl::start_to_stream(_listChanges, _lifetime);
+	if (_owningTopic) {
+		_owningTopic->destroyed(
+		) | rpl::start_with_next([=] {
+			_owningTopic = nullptr;
+			subscribeToUpdates();
+		}, _lifetime);
+	} else {
+		subscribeToUpdates();
+	}
 }
 
 RepliesList::~RepliesList() {
@@ -105,6 +91,48 @@ RepliesList::~RepliesList() {
 	}
 }
 
+void RepliesList::subscribeToUpdates() {
+	_history->owner().repliesReadTillUpdates(
+	) | rpl::filter([=](const RepliesReadTillUpdate &update) {
+		return (update.id.msg == _rootId)
+			&& (update.id.peer == _history->peer->id);
+	}) | rpl::start_with_next([=](const RepliesReadTillUpdate &update) {
+		apply(update);
+	}, _lifetime);
+
+	_history->session().changes().messageUpdates(
+		MessageUpdate::Flag::NewAdded
+		| MessageUpdate::Flag::NewMaybeAdded
+		| MessageUpdate::Flag::ReplyToTopAdded
+		| MessageUpdate::Flag::Destroyed
+	) | rpl::start_with_next([=](const MessageUpdate &update) {
+		apply(update);
+	}, _lifetime);
+
+	_history->owner().channelDifferenceTooLong(
+	) | rpl::start_with_next([=](not_null<ChannelData*> channel) {
+		if (channel == _history->peer) {
+			applyDifferenceTooLong();
+		}
+	}, _lifetime);
+}
+
+void RepliesList::apply(const RepliesReadTillUpdate &update) {
+	if (update.out) {
+		setOutboxReadTill(update.readTillId);
+	} else if (update.readTillId >= _inboxReadTillId) {
+		setInboxReadTill(
+			update.readTillId,
+			computeUnreadCountLocally(update.readTillId));
+	}
+}
+
+void RepliesList::apply(const MessageUpdate &update) {
+	if (applyUpdate(update)) {
+		_instantChanges.fire({});
+	}
+}
+
 rpl::producer<MessagesSlice> RepliesList::source(
 		MessagePosition aroundId,
 		int limitBefore,
@@ -426,14 +454,11 @@ bool RepliesList::applyUpdate(const MessageUpdate &update) {
 	return true;
 }
 
-bool RepliesList::applyDifferenceTooLong(not_null<ChannelData*> channel) {
-	if (_creating
-		|| _history->peer != channel
-		|| !_skippedAfter.has_value()) {
-		return false;
+void RepliesList::applyDifferenceTooLong() {
+	if (!_creating && _skippedAfter.has_value()) {
+		_skippedAfter = std::nullopt;
+		_listChanges.fire({});
 	}
-	_skippedAfter = std::nullopt;
-	return true;
 }
 
 void RepliesList::changeUnreadCountByPost(MsgId id, int delta) {

Telegram/SourceFiles/data/data_replies_list.h

@@ -15,16 +15,25 @@ class HistoryService;
 
 namespace Data {
 
+class ForumTopic;
 class Histories;
 struct MessagePosition;
 struct MessagesSlice;
 struct MessageUpdate;
+struct RepliesReadTillUpdate;
 
 class RepliesList final : public base::has_weak_ptr {
 public:
-	RepliesList(not_null<History*> history, MsgId rootId);
+	RepliesList(
+		not_null<History*> history,
+		MsgId rootId,
+		ForumTopic *owningTopic = nullptr);
 	~RepliesList();
 
+	void apply(const RepliesReadTillUpdate &update);
+	void apply(const MessageUpdate &update);
+	void applyDifferenceTooLong();
+
 	[[nodiscard]] rpl::producer<MessagesSlice> source(
 		MessagePosition aroundId,
 		int limitBefore,
@@ -66,6 +75,7 @@ private:
 	HistoryItem *lookupRoot();
 	[[nodiscard]] Histories &histories();
 
+	void subscribeToUpdates();
 	[[nodiscard]] rpl::producer<MessagesSlice> sourceFromServer(
 		MessagePosition aroundId,
 		int limitBefore,
@@ -77,8 +87,6 @@ private:
 		not_null<Viewer*> viewer,
 		not_null<HistoryItem*> item);
 	[[nodiscard]] bool applyUpdate(const MessageUpdate &update);
-	[[nodiscard]] bool applyDifferenceTooLong(
-		not_null<ChannelData*> channel);
 	void injectRootMessageAndReverse(not_null<Viewer*> viewer);
 	void injectRootMessage(not_null<Viewer*> viewer);
 	void injectRootDivider(
@@ -97,6 +105,7 @@ private:
 	void reloadUnreadCountIfNeeded();
 
 	const not_null<History*> _history;
+	ForumTopic *_owningTopic = nullptr;
 	const MsgId _rootId = 0;
 	const bool _creating = false;
 

Telegram/SourceFiles/data/data_session.cpp

@@ -56,6 +56,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_wall_paper.h"
 #include "data/data_game.h"
 #include "data/data_poll.h"
+#include "data/data_replies_list.h"
 #include "data/data_chat_filters.h"
 #include "data/data_scheduled_messages.h"
 #include "data/data_send_action.h"
@@ -292,6 +293,8 @@ Session::Session(not_null<Main::Session*> session)
 		}
 	}, _lifetime);
 
+	subscribeForTopicRepliesLists();
+
 	crl::on_main(_session, [=] {
 		AmPremiumValue(
 			_session
@@ -307,6 +310,37 @@ Session::Session(not_null<Main::Session*> session)
 	});
 }
 
+void Session::subscribeForTopicRepliesLists() {
+	repliesReadTillUpdates(
+	) | rpl::start_with_next([=](const RepliesReadTillUpdate &update) {
+		if (const auto peer = peerLoaded(update.id.peer)) {
+			if (const auto topic = peer->forumTopicFor(update.id.msg)) {
+				topic->replies()->apply(update);
+			}
+		}
+	}, _lifetime);
+
+	session().changes().messageUpdates(
+		MessageUpdate::Flag::NewAdded
+		| MessageUpdate::Flag::NewMaybeAdded
+		| MessageUpdate::Flag::ReplyToTopAdded
+		| MessageUpdate::Flag::Destroyed
+	) | rpl::start_with_next([=](const MessageUpdate &update) {
+		if (const auto topic = update.item->topic()) {
+			topic->replies()->apply(update);
+		}
+	}, _lifetime);
+
+	channelDifferenceTooLong(
+	) | rpl::start_with_next([=](not_null<ChannelData*> channel) {
+		if (const auto forum = channel->forum()) {
+			forum->enumerateTopics([](not_null<ForumTopic*> topic) {
+				topic->replies()->applyDifferenceTooLong();
+			});
+		}
+	}, _lifetime);
+}
+
 void Session::clear() {
 	// Optimization: clear notifications before destroying items.
 	Core::App().notifications().clearFromSession(_session);

Telegram/SourceFiles/data/data_session.h

@@ -143,6 +143,7 @@ public:
 		return ++_nonHistoryEntryId;
 	}
 
+	void subscribeForTopicRepliesLists();
 	void clear();
 
 	void keepAlive(std::shared_ptr<PhotoMedia> media);