Prepare Data::Histories for requests interdependencies.

Telegram/SourceFiles/data/data_histories.h

@@ -0,0 +1,93 @@
+/*
+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 "base/timer.h"
+
+class History;
+class HistoryItem;
+
+namespace Main {
+class Session;
+} // namespace Main
+
+namespace Data {
+
+class Session;
+
+class Histories final {
+public:
+	explicit Histories(not_null<Session*> owner);
+
+	[[nodiscard]] Session &owner() const;
+	[[nodiscard]] Main::Session &session() const;
+
+	[[nodiscard]] History *find(PeerId peerId);
+	[[nodiscard]] not_null<History*> findOrCreate(PeerId peerId);
+
+	void unloadAll();
+	void clearAll();
+
+	void readInboxTill(
+		not_null<History*> history,
+		not_null<HistoryItem*> item);
+	void sendPendingReadInbox(not_null<History*> history);
+
+private:
+	enum class RequestType : uchar {
+		None,
+		DialogsEntry,
+		History,
+		ReadInbox,
+		Delete,
+	};
+	enum class Action : uchar {
+		Send,
+		Postpone,
+		Skip,
+	};
+	struct PostponedRequest {
+		Fn<mtpRequestId(Fn<void()> done)> generator;
+		RequestType type = RequestType::None;
+	};
+	struct SentRequest {
+		mtpRequestId id = 0;
+		RequestType type = RequestType::None;
+	};
+	struct State {
+		base::flat_map<int, PostponedRequest> postponed;
+		base::flat_map<int, SentRequest> sent;
+		crl::time readWhen = 0;
+		MsgId readTill = 0;
+		int autoincrement = 0;
+		bool thenRequestEntry = false;
+	};
+
+	void sendReadRequests();
+	void sendReadRequest(not_null<History*> history, State &state);
+	[[nodiscard]] State *lookup(not_null<History*> history);
+	void checkEmptyState(not_null<History*> history);
+	int sendRequest(
+		not_null<History*> history,
+		RequestType type,
+		Fn<mtpRequestId(Fn<void()> done)> generator);
+	void checkPostponed(not_null<History*> history, int requestId);
+	[[nodiscard]] Action chooseAction(
+		State &state,
+		RequestType type,
+		bool fromPostponed = false) const;
+
+	const not_null<Session*> _owner;
+
+	std::unordered_map<PeerId, std::unique_ptr<History>> _map;
+	base::flat_map<not_null<History*>, State> _states;
+	base::Timer _readRequestsTimer;
+
+};
+
+} // namespace Data