From 909acb25fdce1c3ed442c35be822b94ee0900e42 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Tue, 24 Apr 2018 11:21:19 +0400
Subject: [PATCH] Requesting config if can't connect.

---
 Telegram/SourceFiles/mtproto/connection.cpp   | 20 +++++++++++++++++--
 Telegram/SourceFiles/mtproto/connection.h     |  1 +
 Telegram/SourceFiles/mtproto/mtp_instance.cpp | 18 +++++++++++++++++
 Telegram/SourceFiles/mtproto/mtp_instance.h   |  1 +
 4 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/Telegram/SourceFiles/mtproto/connection.cpp b/Telegram/SourceFiles/mtproto/connection.cpp
index f79e49fbd..047bd46a8 100644
--- a/Telegram/SourceFiles/mtproto/connection.cpp
+++ b/Telegram/SourceFiles/mtproto/connection.cpp
@@ -30,6 +30,9 @@ constexpr auto kRecreateKeyId = AuthKey::KeyId(0xFFFFFFFFFFFFFFFFULL);
 constexpr auto kIntSize = static_cast<int>(sizeof(mtpPrime));
 constexpr auto kMaxModExpSize = 256;
 
+// If we can't connect for this time we will ask _instance to update config.
+constexpr auto kRequestConfigTimeout = TimeMs(8000);
+
 // Don't try to handle messages larger than this size.
 constexpr auto kMaxMessageLength = 16 * 1024 * 1024;
 
@@ -356,6 +359,7 @@ ConnectionPrivate::ConnectionPrivate(Instance *instance, QThread *thread, Connec
 , _state(DisconnectedState)
 , _shiftedDcId(shiftedDcId)
 , _owner(owner)
+, _configWasFineAt(getms(true))
 , _waitForReceived(MTPMinReceiveDelay)
 , _waitForConnected(MTPMinConnectDelay)
 //, sessionDataMutex(QReadWriteLock::Recursive)
@@ -1031,11 +1035,21 @@ void ConnectionPrivate::connectToServer(bool afterConfig) {
 		DEBUG_LOG(("MTP Info: DC %1 options for IPv4 over HTTP not found, waiting for config").arg(_shiftedDcId));
 		if (Global::TryIPv6() && noIPv6) DEBUG_LOG(("MTP Info: DC %1 options for IPv6 over HTTP not found, waiting for config").arg(_shiftedDcId));
 		connect(_instance, SIGNAL(configLoaded()), this, SLOT(onConfigLoaded()), Qt::UniqueConnection);
-		InvokeQueued(_instance, [instance = _instance] { instance->requestConfig(); });
+		InvokeQueued(_instance, [instance = _instance] {
+			instance->requestConfig();
+		});
 		return;
 	}
 
-	if (afterConfig && (_conn4 || _conn6)) return;
+	if (afterConfig) {
+		if (_conn4 || _conn6) {
+			return;
+		}
+	} else if (getms(true) - _configWasFineAt > kRequestConfigTimeout) {
+		InvokeQueued(_instance, [instance = _instance] {
+			instance->requestConfigIfOld();
+		});
+	}
 
 	createConn(!noIPv4, !noIPv6);
 	retryTimer.stop();
@@ -2340,6 +2354,8 @@ void ConnectionPrivate::updateAuthKey() 	{
 	QReadLocker lockFinished(&sessionDataMutex);
 	if (!sessionData || !_conn) return;
 
+	_configWasFineAt = getms(true);
+
 	DEBUG_LOG(("AuthKey Info: Connection updating key from Session, dc %1").arg(_shiftedDcId));
 	uint64 newKeyId = 0;
 	{
diff --git a/Telegram/SourceFiles/mtproto/connection.h b/Telegram/SourceFiles/mtproto/connection.h
index 04db423a3..1e88755e7 100644
--- a/Telegram/SourceFiles/mtproto/connection.h
+++ b/Telegram/SourceFiles/mtproto/connection.h
@@ -197,6 +197,7 @@ private:
 	AbstractConnection *_conn = nullptr;
 	AbstractConnection *_conn4 = nullptr;
 	AbstractConnection *_conn6 = nullptr;
+	TimeMs _configWasFineAt = 0;
 
 	SingleTimer retryTimer; // exp retry timer
 	int retryTimeout = 1;
diff --git a/Telegram/SourceFiles/mtproto/mtp_instance.cpp b/Telegram/SourceFiles/mtproto/mtp_instance.cpp
index d1056d756..782f51a3c 100644
--- a/Telegram/SourceFiles/mtproto/mtp_instance.cpp
+++ b/Telegram/SourceFiles/mtproto/mtp_instance.cpp
@@ -23,6 +23,11 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/timer.h"
 
 namespace MTP {
+namespace {
+
+constexpr auto kConfigBecomesOldIn = 2 * 60 * TimeMs(1000);
+
+} // namespace
 
 class Instance::Private : private Sender {
 public:
@@ -41,6 +46,7 @@ public:
 	not_null<DcOptions*> dcOptions();
 
 	void requestConfig();
+	void requestConfigIfOld();
 	void requestCDNConfig();
 
 	void restart();
@@ -149,6 +155,7 @@ private:
 
 	std::unique_ptr<internal::ConfigLoader> _configLoader;
 	mtpRequestId _cdnConfigLoadRequestId = 0;
+	TimeMs _lastConfigLoadedTime = 0;
 
 	std::map<DcId, AuthKeyPtr> _keysForWrite;
 	mutable QReadWriteLock _keysForWriteLock;
@@ -284,6 +291,12 @@ void Instance::Private::requestConfig() {
 	_configLoader->load();
 }
 
+void Instance::Private::requestConfigIfOld() {
+	if (getms(true) - _lastConfigLoadedTime >= kConfigBecomesOldIn) {
+		requestConfig();
+	}
+}
+
 void Instance::Private::requestCDNConfig() {
 	if (_cdnConfigLoadRequestId || _mainDcId == Config::kNoneMainDc) {
 		return;
@@ -580,6 +593,7 @@ void Instance::Private::configLoadDone(const MTPConfig &result) {
 	Expects(result.type() == mtpc_config);
 
 	_configLoader.reset();
+	_lastConfigLoadedTime = getms(true);
 
 	auto &data = result.c_config();
 	DEBUG_LOG(("MTP Info: got config, chat_size_max: %1, date: %2, test_mode: %3, this_dc: %4, dc_options.length: %5").arg(data.vchat_size_max.v).arg(data.vdate.v).arg(mtpIsTrue(data.vtest_mode)).arg(data.vthis_dc.v).arg(data.vdc_options.v.size()));
@@ -1310,6 +1324,10 @@ void Instance::requestConfig() {
 	_private->requestConfig();
 }
 
+void Instance::requestConfigIfOld() {
+	_private->requestConfigIfOld();
+}
+
 void Instance::requestCDNConfig() {
 	_private->requestCDNConfig();
 }
diff --git a/Telegram/SourceFiles/mtproto/mtp_instance.h b/Telegram/SourceFiles/mtproto/mtp_instance.h
index 4aad164f7..c4929055f 100644
--- a/Telegram/SourceFiles/mtproto/mtp_instance.h
+++ b/Telegram/SourceFiles/mtproto/mtp_instance.h
@@ -135,6 +135,7 @@ public:
 	void scheduleKeyDestroy(ShiftedDcId shiftedDcId);
 
 	void requestConfig();
+	void requestConfigIfOld();
 	void requestCDNConfig();
 
 	~Instance();