Preload stories in both directions.

Telegram/SourceFiles/data/data_stories.cpp

@@ -28,6 +28,8 @@ namespace Data {
 namespace {
 
 constexpr auto kMaxResolveTogether = 100;
+constexpr auto kIgnorePreloadAroundIfLoaded = 15;
+constexpr auto kPreloadAroundCount = 30;
 
 using UpdateFlag = StoryUpdate::Flag;
 
@@ -322,36 +324,31 @@ void Stories::loadMore() {
 }
 
 void Stories::sendResolveRequests() {
-	if (!_resolveRequests.empty()) {
+	if (!_resolveSent.empty()) {
 		return;
 	}
-	struct Prepared {
-		QVector<MTPint> ids;
-		std::vector<Fn<void()>> callbacks;
-	};
 	auto leftToSend = kMaxResolveTogether;
-	auto byPeer = base::flat_map<PeerId, Prepared>();
+	auto byPeer = base::flat_map<PeerId, QVector<MTPint>>();
-	for (auto i = begin(_resolves); i != end(_resolves);) {
+	for (auto i = begin(_resolvePending); i != end(_resolvePending);) {
 		auto &[peerId, ids] = *i;
-		auto &prepared = byPeer[peerId];
+		auto &sent = _resolveSent[peerId];
-		for (auto &[storyId, callbacks] : ids) {
+		if (ids.size() <= leftToSend) {
-			prepared.ids.push_back(MTP_int(storyId));
+			sent = base::take(ids);
-			prepared.callbacks.insert(
+			i = _resolvePending.erase(i);
-				end(prepared.callbacks),
+			leftToSend -= int(sent.size());
-				std::make_move_iterator(begin(callbacks)),
-				std::make_move_iterator(end(callbacks)));
-			if (!--leftToSend) {
-				break;
-			}
-		}
-		const auto sending = int(prepared.ids.size());
-		if (sending == ids.size()) {
-			i = _resolves.erase(i);
-			if (!leftToSend) {
-				break;
-			}
 		} else {
-			ids.erase(begin(ids), begin(ids) + sending);
+			sent = {
+				std::make_move_iterator(begin(ids)),
+				std::make_move_iterator(begin(ids) + leftToSend)
+			};
+			ids.erase(begin(ids), begin(ids) + leftToSend);
+			leftToSend = 0;
+		}
+		auto &prepared = byPeer[peerId];
+		for (auto &[storyId, callbacks] : sent) {
+			prepared.push_back(MTP_int(storyId));
+		}
+		if (!leftToSend) {
 			break;
 		}
 	}
@@ -359,36 +356,35 @@ void Stories::sendResolveRequests() {
 	for (auto &entry : byPeer) {
 		const auto peerId = entry.first;
 		auto &prepared = entry.second;
-		const auto finish = [=, ids = prepared.ids](mtpRequestId id) {
+		const auto finish = [=](PeerId peerId) {
-			for (const auto &id : ids) {
+			const auto sent = _resolveSent.take(peerId);
-				finalizeResolve({ peerId, id.v });
+			Assert(sent.has_value());
-			}
+			for (const auto &[storyId, list] : *sent) {
-			if (auto callbacks = _resolveRequests.take(id)) {
+				finalizeResolve({ peerId, storyId });
-				for (const auto &callback : *callbacks) {
+				for (const auto &callback : list) {
 					callback();
 				}
 			}
-			if (_resolveRequests.empty() && !_resolves.empty()) {
+			_itemsChanged.fire_copy(peerId);
+			if (_resolveSent.empty() && !_resolvePending.empty()) {
 				crl::on_main(&session(), [=] { sendResolveRequests(); });
 			}
 		};
 		const auto user = _owner->session().data().peer(peerId)->asUser();
 		if (!user) {
-			_resolveRequests[0] = std::move(prepared.callbacks);
+			finish(peerId);
-			finish(0);
 			continue;
 		}
 		const auto requestId = api->request(MTPstories_GetStoriesByID(
 			user->inputUser,
-			MTP_vector<MTPint>(std::move(prepared.ids))
+			MTP_vector<MTPint>(prepared)
-		)).done([=](const MTPstories_Stories &result, mtpRequestId id) {
+		)).done([=](const MTPstories_Stories &result) {
 			owner().processUsers(result.data().vusers());
 			processResolvedStories(user, result.data().vstories().v);
-			finish(id);
+			finish(user->id);
-		}).fail([=](const MTP::Error &error, mtpRequestId id) {
+		}).fail([=] {
-			finish(id);
+			finish(peerId);
 		}).send();
-		_resolveRequests.emplace(requestId, std::move(prepared.callbacks));
 	 }
 }
 
@@ -476,6 +472,10 @@ rpl::producer<> Stories::allChanged() const {
 	return _allChanged.events();
 }
 
+rpl::producer<PeerId> Stories::itemsChanged() const {
+	return _itemsChanged.events();
+}
+
 base::expected<not_null<Story*>, NoStory> Stories::lookup(
 		FullStoryId id) const {
 	const auto i = _stories.find(id.peer);
@@ -492,10 +492,20 @@ base::expected<not_null<Story*>, NoStory> Stories::lookup(
 void Stories::resolve(FullStoryId id, Fn<void()> done) {
 	const auto already = lookup(id);
 	if (already.has_value() || already.error() != NoStory::Unknown) {
-		done();
+		if (done) {
+			done();
+		}
 		return;
 	}
-	auto &ids = _resolves[id.peer];
+	if (const auto i = _resolveSent.find(id.peer); i != end(_resolveSent)) {
+		if (const auto j = i->second.find(id.story); j != end(i->second)) {
+			if (done) {
+				j->second.push_back(std::move(done));
+			}
+			return;
+		}
+	}
+	auto &ids = _resolvePending[id.peer];
 	if (ids.empty()) {
 		crl::on_main(&session(), [=] {
 			sendResolveRequests();
@@ -525,7 +535,7 @@ void Stories::applyChanges(StoriesList &&list) {
 		auto added = false;
 		for (const auto id : list.ids) {
 			if (!ranges::contains(i->ids, id)) {
-				i->ids.insert(begin(i->ids), id);
+				i->ids.push_back(id);
 				++i->total;
 				added = true;
 			}
@@ -538,4 +548,40 @@ void Stories::applyChanges(StoriesList &&list) {
 	}
 }
 
+void Stories::loadAround(FullStoryId id) {
+	const auto i = ranges::find(_all, id.peer, [](const StoriesList &list) {
+		return list.user->id;
+	});
+	if (i == end(_all)) {
+		return;
+	}
+	const auto j = ranges::find(i->ids, id.story);
+	if (j == end(i->ids)) {
+		return;
+	}
+	const auto ignore = [&] {
+		const auto side = kIgnorePreloadAroundIfLoaded;
+		const auto left = ranges::min(j - begin(i->ids), side);
+		const auto right = ranges::min(end(i->ids) - j, side);
+		for (auto k = j - left; k != j + right; ++k) {
+			const auto maybeStory = lookup({ id.peer, *k });
+			if (!maybeStory && maybeStory.error() == NoStory::Unknown) {
+				return false;
+			}
+		}
+		return true;
+	}();
+	if (ignore) {
+		return;
+	}
+	const auto side = kPreloadAroundCount;
+	const auto left = ranges::min(j - begin(i->ids), side);
+	const auto right = ranges::min(end(i->ids) - j, side);
+	const auto from = j - left;
+	const auto till = j + right;
+	for (auto k = from; k != till; ++k) {
+		resolve({ id.peer, *k }, nullptr);
+	}
+}
+
 } // namespace Data

Telegram/SourceFiles/data/data_stories.h

@@ -102,10 +102,12 @@ public:
 
 	void loadMore();
 	void apply(const MTPDupdateStories &data);
+	void loadAround(FullStoryId id);
 
 	[[nodiscard]] const std::vector<StoriesList> &all();
 	[[nodiscard]] bool allLoaded() const;
 	[[nodiscard]] rpl::producer<> allChanged() const;
+	[[nodiscard]] rpl::producer<PeerId> itemsChanged() const;
 
 	[[nodiscard]] base::expected<not_null<Story*>, NoStory> lookup(
 		FullStoryId id) const;
@@ -135,8 +137,10 @@ private:
 
 	base::flat_map<
 		PeerId,
-		base::flat_map<StoryId, std::vector<Fn<void()>>>> _resolves;
+		base::flat_map<StoryId, std::vector<Fn<void()>>>> _resolvePending;
-	base::flat_map<mtpRequestId, std::vector<Fn<void()>>> _resolveRequests;
+	base::flat_map<
+		PeerId,
+		base::flat_map<StoryId, std::vector<Fn<void()>>>> _resolveSent;
 
 	std::map<
 		not_null<Data::Story*>,
@@ -144,6 +148,7 @@ private:
 
 	std::vector<StoriesList> _all;
 	rpl::event_stream<> _allChanged;
+	rpl::event_stream<PeerId> _itemsChanged;
 	QString _state;
 	bool _allLoaded = false;
 

Telegram/SourceFiles/media/stories/media_stories_controller.cpp

@@ -361,10 +361,11 @@ void Controller::show(
 
 	const auto &list = lists[index];
 	const auto id = list.ids[subindex];
-	const auto maybeStory = list.user->owner().stories().lookup({
+	const auto storyId = FullStoryId{
 		.peer = list.user->id,
 		.story = id,
-	});
+	};
+	const auto maybeStory = list.user->owner().stories().lookup(storyId);
 	if (!maybeStory) {
 		return;
 	}
@@ -381,15 +382,8 @@ void Controller::show(
 		_list = list;
 	}
 	_index = subindex;
+	_waitingForId = {};
 
-	if (int(lists.size()) - index < kPreloadUsersCount) {
-		story->peer()->owner().stories().loadMore();
-	}
-
-	const auto storyId = FullStoryId{
-		.peer = list.user->id,
-		.story = id,
-	};
 	if (_shown == storyId) {
 		return;
 	}
@@ -411,8 +405,20 @@ void Controller::show(
 				_delegate->storiesClose();
 			}
 		});
+		session->data().stories().itemsChanged(
+		) | rpl::start_with_next([=](PeerId peerId) {
+			if (_waitingForId.peer == peerId) {
+				checkWaitingFor();
+			}
+		}, _sessionLifetime);
 	}
 
+	auto &stories = session->data().stories();
+	if (int(lists.size()) - index < kPreloadUsersCount) {
+		stories.loadMore();
+	}
+	stories.loadAround(storyId);
+
 	if (_contentFaded) {
 		togglePaused(true);
 	}
@@ -483,25 +489,61 @@ bool Controller::subjumpFor(int delta) {
 		} else if (!_list || _list->ids.empty()) {
 			return false;
 		}
-		_delegate->storiesJumpTo(&_list->user->session(), {
+		subjumpTo(0);
-			.peer = _list->user->id,
-			.story = _list->ids.front()
-		});
 		return true;
 	} else if (index >= _list->total) {
 		return _siblingRight
 			&& _siblingRight->shownId().valid()
 			&& jumpFor(1);
 	} else if (index < _list->ids.size()) {
-		// #TODO stories load more
+		subjumpTo(index);
-		_delegate->storiesJumpTo(&_list->user->session(), {
-			.peer = _list->user->id,
-			.story = _list->ids[index]
-		});
 	}
 	return true;
 }
 
+void Controller::subjumpTo(int index) {
+	Expects(_list.has_value());
+	Expects(index >= 0 && index < _list->ids.size());
+
+	const auto id = FullStoryId{
+		.peer = _list->user->id,
+		.story = _list->ids[index]
+	};
+	auto &stories = _list->user->owner().stories();
+	if (stories.lookup(id)) {
+		_delegate->storiesJumpTo(&_list->user->session(), id);
+	} else if (_waitingForId != id) {
+		_waitingForId = id;
+		stories.loadAround(id);
+	}
+}
+
+void Controller::checkWaitingFor() {
+	Expects(_waitingForId.valid());
+	Expects(_list.has_value());
+
+	auto &stories = _list->user->owner().stories();
+	const auto &all = stories.all();
+	const auto i = ranges::find_if(all, [&](const Data::StoriesList &data) {
+		return data.user->id == _waitingForId.peer;
+	});
+	if (i == end(all)) {
+		_waitingForId = {};
+		return;
+	}
+	const auto j = ranges::find(i->ids, _waitingForId.story);
+	if (j == end(i->ids)) {
+		_waitingForId = {};
+		return;
+	}
+	const auto maybe = stories.lookup(_waitingForId);
+	if (!maybe) {
+		return;
+	}
+	_delegate->storiesJumpTo(
+		&_list->user->session(),
+		base::take(_waitingForId));
+}
 
 bool Controller::jumpFor(int delta) {
 	if (delta == -1) {

Telegram/SourceFiles/media/stories/media_stories_controller.h

@@ -131,6 +131,9 @@ private:
 		std::unique_ptr<Sibling> &sibling,
 		const Data::StoriesList *list);
 
+	void subjumpTo(int index);
+	void checkWaitingFor();
+
 	const not_null<Delegate*> _delegate;
 
 	rpl::variable<std::optional<Layout>> _layout;
@@ -148,6 +151,7 @@ private:
 	FullStoryId _shown;
 	TextWithEntities _captionText;
 	std::optional<Data::StoriesList> _list;
+	FullStoryId _waitingForId;
 	int _index = 0;
 	bool _started = false;