Count unread replies locally when possible.

Telegram/SourceFiles/api/api_updates.cpp

@@ -2094,7 +2094,9 @@ void Updates::feedUpdate(const MTPUpdate &update) {
 		const auto msgId = d.vtop_msg_id().v;
 		const auto readTillId = d.vread_max_id().v;
 		const auto item = session().data().message(channelId, msgId);
-		const auto unreadCount = std::nullopt;
+		const auto unreadCount = item
+			? session().data().countUnreadRepliesLocally(item, readTillId)
+			: std::nullopt;
 		if (item) {
 			item->setRepliesInboxReadTill(readTillId, unreadCount);
 			if (const auto post = item->lookupDiscussionPostOriginal()) {

Telegram/SourceFiles/data/data_session.cpp

@@ -2360,6 +2360,23 @@ void Session::notifyUnreadBadgeChanged() {
 	_unreadBadgeChanges.fire({});
 }
 
+std::optional<int> Session::countUnreadRepliesLocally(
+		not_null<HistoryItem*> root,
+		MsgId afterId) const {
+	auto result = std::optional<int>();
+	_unreadRepliesCountRequests.fire({
+		.root = root,
+		.afterId = afterId,
+		.result = &result,
+	});
+	return result;
+}
+
+auto Session::unreadRepliesCountRequests() const
+-> rpl::producer<UnreadRepliesCountRequest> {
+	return _unreadRepliesCountRequests.events();
+}
+
 int Session::computeUnreadBadge(const Dialogs::UnreadState &state) const {
 	const auto all = Core::App().settings().includeMutedCounter();
 	return std::max(state.marks - (all ? 0 : state.marksMuted), 0)

Telegram/SourceFiles/data/data_session.h

@@ -430,11 +430,23 @@ public:
 	[[nodiscard]] int unreadBadge() const;
 	[[nodiscard]] bool unreadBadgeMuted() const;
 	[[nodiscard]] int unreadBadgeIgnoreOne(const Dialogs::Key &key) const;
-	[[nodiscard]] bool unreadBadgeMutedIgnoreOne(const Dialogs::Key &key) const;
+	[[nodiscard]] bool unreadBadgeMutedIgnoreOne(
+		const Dialogs::Key &key) const;
 	[[nodiscard]] int unreadOnlyMutedBadge() const;
 	[[nodiscard]] rpl::producer<> unreadBadgeChanges() const;
 	void notifyUnreadBadgeChanged();
 
+	[[nodiscard]] std::optional<int> countUnreadRepliesLocally(
+		not_null<HistoryItem*> root,
+		MsgId afterId) const;
+	struct UnreadRepliesCountRequest {
+		not_null<HistoryItem*> root;
+		MsgId afterId = 0;
+		not_null<std::optional<int>*> result;
+	};
+	[[nodiscard]] auto unreadRepliesCountRequests() const
+		-> rpl::producer<UnreadRepliesCountRequest>;
+
 	void selfDestructIn(not_null<HistoryItem*> item, crl::time delay);
 
 	[[nodiscard]] not_null<PhotoData*> photo(PhotoId id);
@@ -855,6 +867,7 @@ private:
 	rpl::event_stream<DialogsRowReplacement> _dialogsRowReplacements;
 	rpl::event_stream<ChatListEntryRefresh> _chatListEntryRefreshes;
 	rpl::event_stream<> _unreadBadgeChanges;
+	rpl::event_stream<UnreadRepliesCountRequest> _unreadRepliesCountRequests;
 
 	Dialogs::MainList _chatsList;
 	Dialogs::IndexedList _contactsList;

Telegram/SourceFiles/history/view/history_view_replies_section.cpp

@@ -275,6 +275,17 @@ RepliesWidget::RepliesWidget(
 		_inner->update();
 	}, lifetime());
 
+	_history->session().data().unreadRepliesCountRequests(
+	) | rpl::filter([=](
+			const Data::Session::UnreadRepliesCountRequest &request) {
+		return (request.root.get() == _root);
+	}) | rpl::start_with_next([=](
+			const Data::Session::UnreadRepliesCountRequest &request) {
+		if (const auto result = computeUnreadCountLocally(request.afterId)) {
+			*request.result = result;
+		}
+	}, lifetime());
+
 	setupScrollDownButton();
 	setupComposeControls();
 	orderWidgets();
@@ -1762,6 +1773,20 @@ void RepliesWidget::listSelectionChanged(SelectedItems &&items) {
 	_topBar->showSelected(state);
 }
 
+std::optional<int> RepliesWidget::computeUnreadCountLocally(
+		MsgId afterId) const {
+	const auto views = _root ? _root->Get<HistoryMessageViews>() : nullptr;
+	if (!views) {
+		return std::nullopt;
+	}
+	const auto wasReadTillId = views->repliesInboxReadTillId;
+	const auto wasUnreadCount = views->repliesUnreadCount;
+	return _replies->fullUnreadCountAfter(
+		afterId,
+		wasReadTillId,
+		wasUnreadCount);
+}
+
 void RepliesWidget::readTill(not_null<HistoryItem*> item) {
 	if (!_root) {
 		return;
@@ -1771,13 +1796,7 @@ void RepliesWidget::readTill(not_null<HistoryItem*> item) {
 	if (now < was) {
 		return;
 	}
-	const auto views = _root->Get<HistoryMessageViews>();
+	const auto unreadCount = computeUnreadCountLocally(now);
-	const auto wasReadTillId = views ? views->repliesInboxReadTillId : 0;
-	const auto wasUnreadCount = views ? views->repliesUnreadCount : -1;
-	const auto unreadCount = _replies->fullUnreadCountAfter(
-		now,
-		wasReadTillId,
-		wasUnreadCount);
 	const auto fast = item->out() || !unreadCount.has_value();
 	if (was < now || (fast && now == was)) {
 		_root->setRepliesInboxReadTill(now, unreadCount);

Telegram/SourceFiles/history/view/history_view_replies_section.h

@@ -173,6 +173,8 @@ private:
 	void setupDragArea();
 	void sendReadTillRequest();
 	void readTill(not_null<HistoryItem*> item);
+	[[nodiscard]] std::optional<int> computeUnreadCountLocally(
+		MsgId afterId) const;
 
 	void setupScrollDownButton();
 	void scrollDownClicked();