Don't always restart connection on config change.

Telegram/SourceFiles/core/application.cpp

@@ -399,14 +399,18 @@ void Application::badMtprotoConfigurationError() {
 
 void Application::startLocalStorage() {
 	Local::start();
-	subscribe(_dcOptions->changed(), [this](const MTP::DcOptions::Ids &ids) {
-		Local::writeSettings();
-		if (const auto instance = activeAccount().mtp()) {
-			for (const auto id : ids) {
-				instance->restart(id);
-			}
-		}
-	});
+
+	const auto writing = _lifetime.make_state<bool>(false);
+	_dcOptions->changed(
+	) | rpl::filter([=] {
+		return !*writing;
+	}) | rpl::start_with_next([=] {
+		*writing = true;
+		Ui::PostponeCall(this, [=] {
+			Local::writeSettings();
+		});
+	}, _lifetime);
+
 	_saveSettingsTimer.setCallback([=] { Local::writeSettings(); });
 }
 

Telegram/SourceFiles/mtproto/connection.cpp

@@ -126,7 +126,9 @@ Connection::~Connection() {
 	}
 }
 
-void Connection::start(std::shared_ptr<SessionData> sessionData, ShiftedDcId shiftedDcId) {
+void Connection::start(
+		std::shared_ptr<SessionData> sessionData,
+		ShiftedDcId shiftedDcId) {
 	Expects(_thread == nullptr && _private == nullptr);
 
 	_thread = std::make_unique<QThread>();
@@ -137,6 +139,16 @@ void Connection::start(std::shared_ptr<SessionData> sessionData, ShiftedDcId shi
 		std::move(sessionData),
 		shiftedDcId);
 
+	_instance->dcOptions()->changed(
+	) | rpl::filter([=](DcId dcId) {
+		return (BareDcId(shiftedDcId) == dcId) && (_private != nullptr);
+	}) | rpl::start_with_next([=] {
+		const auto raw = _private;
+		InvokeQueued(raw, [=] {
+			raw->dcOptionsChanged();
+		});
+	}, _lifetime);
+
 	// will be deleted in the thread::finished signal
 	_private = newData.release();
 	_thread->start();
@@ -329,10 +341,6 @@ ConnectionPrivate::~ConnectionPrivate() {
 	Expects(_testConnections.empty());
 }
 
-void ConnectionPrivate::onConfigLoaded() {
-	connectToServer(true);
-}
-
 void ConnectionPrivate::onCDNConfigLoaded() {
 	restart();
 }
@@ -341,6 +349,11 @@ int32 ConnectionPrivate::getShiftedDcId() const {
 	return _shiftedDcId;
 }
 
+void ConnectionPrivate::dcOptionsChanged() {
+	_retryTimeout = 1;
+	connectToServer(true);
+}
+
 int32 ConnectionPrivate::getState() const {
 	QReadLocker lock(&_stateMutex);
 	int32 result = _state;
@@ -1004,7 +1017,6 @@ void ConnectionPrivate::connectToServer(bool afterConfig) {
 			return restart();
 		}
 		DEBUG_LOG(("MTP Info: DC %1 options not found, waiting for config").arg(_shiftedDcId));
-		connect(_instance, SIGNAL(configLoaded()), this, SLOT(onConfigLoaded()), Qt::UniqueConnection);
 		InvokeQueued(_instance, [instance = _instance] {
 			instance->requestConfig();
 		});

Telegram/SourceFiles/mtproto/connection.h

@@ -58,6 +58,7 @@ private:
 	not_null<Instance*> _instance;
 	std::unique_ptr<QThread> _thread;
 	ConnectionPrivate *_private = nullptr;
+	rpl::lifetime _lifetime;
 
 };
 
@@ -76,6 +77,7 @@ public:
 	void stop();
 
 	int32 getShiftedDcId() const;
+	void dcOptionsChanged();
 
 	int32 getState() const;
 	QString transport() const;
@@ -90,7 +92,6 @@ public slots:
 
 	void updateAuthKey();
 
-	void onConfigLoaded();
 	void onCDNConfigLoaded();
 
 private:

Telegram/SourceFiles/mtproto/dc_options.cpp

@@ -170,7 +170,7 @@ void DcOptions::processFromList(
 		ApplyOneOption(data, dcId, flags, ip, port, secret);
 	}
 
-	auto difference = [&] {
+	const auto difference = [&] {
 		WriteLocker lock(this);
 		auto result = CountOptionsDifference(_data, data);
 		if (!result.empty()) {
@@ -178,8 +178,8 @@ void DcOptions::processFromList(
 		}
 		return result;
 	}();
-	if (!difference.empty()) {
-		_changed.notify(std::move(difference));
+	for (const auto dcId : difference) {
+		_changed.fire_copy(dcId);
 	}
 }
 
@@ -232,9 +232,8 @@ void DcOptions::addFromOther(DcOptions &&options) {
 			}
 		}
 	}
-
-	if (!idsChanged.empty()) {
-		_changed.notify(std::move(idsChanged));
+	for (const auto dcId : idsChanged) {
+		_changed.fire_copy(dcId);
 	}
 }
 
@@ -280,10 +279,10 @@ bool DcOptions::ApplyOneOption(
 	return true;
 }
 
-auto DcOptions::CountOptionsDifference(
+std::vector<DcId> DcOptions::CountOptionsDifference(
 		const std::map<DcId, std::vector<Endpoint>> &a,
-		const std::map<DcId, std::vector<Endpoint>> &b) -> Ids {
-	auto result = Ids();
+		const std::map<DcId, std::vector<Endpoint>> &b) {
+	auto result = std::vector<DcId>();
 	const auto find = [](
 			const std::vector<Endpoint> &where,
 			const Endpoint &what) {
@@ -514,8 +513,12 @@ void DcOptions::constructFromSerialized(const QByteArray &serialized) {
 	}
 }
 
-DcOptions::Ids DcOptions::configEnumDcIds() const {
-	auto result = Ids();
+rpl::producer<DcId> DcOptions::changed() const {
+	return _changed.events();
+}
+
+std::vector<DcId> DcOptions::configEnumDcIds() const {
+	auto result = std::vector<DcId>();
 	{
 		ReadLocker lock(this);
 		result.reserve(_data.size());

Telegram/SourceFiles/mtproto/dc_options.h

@@ -66,15 +66,12 @@ public:
 		const bytes::vector &secret);
 	QByteArray serialize() const;
 
-	using Ids = std::vector<DcId>;
-	base::Observable<Ids> &changed() const {
-		return _changed;
-	}
+	[[nodiscard]] rpl::producer<DcId> changed() const;
 	void setFromList(const MTPVector<MTPDcOption> &options);
 	void addFromList(const MTPVector<MTPDcOption> &options);
 	void addFromOther(DcOptions &&options);
 
-	Ids configEnumDcIds() const;
+	[[nodiscard]] std::vector<DcId> configEnumDcIds() const;
 
 	struct Variants {
 		enum Address {
@@ -119,7 +116,7 @@ private:
 		const std::string &ip,
 		int port,
 		const bytes::vector &secret);
-	static Ids CountOptionsDifference(
+	static std::vector<DcId> CountOptionsDifference(
 		const std::map<DcId, std::vector<Endpoint>> &a,
 		const std::map<DcId, std::vector<Endpoint>> &b);
 	static void FilterIfHasWithFlag(Variants &variants, Flag flag);
@@ -143,7 +140,7 @@ private:
 	std::map<DcId, std::map<uint64, internal::RSAPublicKey>> _cdnPublicKeys;
 	mutable QReadWriteLock _useThroughLockers;
 
-	mutable base::Observable<Ids> _changed;
+	rpl::event_stream<DcId> _changed;
 
 	// True when we have overriden options from a .tdesktop-endpoints file.
 	bool _immutable = false;

Telegram/SourceFiles/mtproto/mtp_instance.cpp

@@ -860,8 +860,6 @@ void Instance::Private::configLoadDone(const MTPConfig &result) {
 	_configExpiresAt = crl::now()
 		+ (data.vexpires().v - base::unixtime::now()) * crl::time(1000);
 	requestConfigIfExpired();
-
-	emit _instance->configLoaded();
 }
 
 bool Instance::Private::configLoadFail(const RPCError &error) {

Telegram/SourceFiles/mtproto/mtp_instance.h

@@ -199,7 +199,6 @@ public:
 	}
 
 signals:
-	void configLoaded();
 	void cdnConfigLoaded();
 	void allKeysDestroyed();
 	void proxyDomainResolved(