Function SharedMediaViewer

Telegram/SourceFiles/data/data_shared_media.cpp:98–188

}

rpl::producer<SparseIdsSlice> SharedMediaViewer(
		not_null<Main::Session*> session,
		Storage::SharedMediaKey key,
		int limitBefore,
		int limitAfter) {
	Expects(IsServerMsgId(key.messageId) || (key.messageId == 0));
	Expects((key.messageId != 0) || (limitBefore == 0 && limitAfter == 0));

	return [=](auto consumer) {
		auto lifetime = rpl::lifetime();
		auto builder = lifetime.make_state<SparseIdsSliceBuilder>(
			key.messageId,
			limitBefore,
			limitAfter);
		auto requestMediaAround = [
			peer = session->data().peer(key.peerId),
			topicRootId = key.topicRootId,
			monoforumPeerId = key.monoforumPeerId,
			type = key.type
		](const SparseIdsSliceBuilder::AroundData &data) {
			peer->session().api().requestSharedMedia(
				peer,
				topicRootId,
				monoforumPeerId,
				type,
				data.aroundId,
				data.direction);
		};
		builder->insufficientAround(
		) | rpl::on_next(requestMediaAround, lifetime);

		auto pushNextSnapshot = [=] {
			consumer.put_next(builder->snapshot());
		};

		using SliceUpdate = Storage::SharedMediaSliceUpdate;
		session->storage().sharedMediaSliceUpdated(
		) | rpl::filter([=](const SliceUpdate &update) {
			return (update.peerId == key.peerId)
				&& (update.topicRootId == key.topicRootId)
				&& (update.monoforumPeerId == key.monoforumPeerId)
				&& (update.type == key.type);
		}) | rpl::filter([=](const SliceUpdate &update) {
			return builder->applyUpdate(update.data);
		}) | rpl::on_next(pushNextSnapshot, lifetime);

		using OneRemoved = Storage::SharedMediaRemoveOne;
		session->storage().sharedMediaOneRemoved(
		) | rpl::filter([=](const OneRemoved &update) {
			return (update.peerId == key.peerId)
				&& update.types.test(key.type);
		}) | rpl::filter([=](const OneRemoved &update) {
			return builder->removeOne(update.messageId);
		}) | rpl::on_next(pushNextSnapshot, lifetime);

		using AllRemoved = Storage::SharedMediaRemoveAll;
		session->storage().sharedMediaAllRemoved(
		) | rpl::filter([=](const AllRemoved &update) {