From da7baf5313c35b87f39ee8394eac6cecaa328772 Mon Sep 17 00:00:00 2001
From: Davide Beatrici <davidebeatrici@gmail.com>
Date: Sat, 25 May 2019 21:33:53 +0200
Subject: [PATCH] ServerUser: use QTime instead of std::chrono and ctime

The legacy implementation (with ctime), used when std::chrono is not available (C++ < 11), caused the client's messages to be permanently blocked until it reconnected.
More specifically, millisecondsBetween() always returned 0.

This commit replaces both implementations with a simpler one which makes use of QTime.
---
 src/murmur/ServerUser.cpp | 32 +++++++-------------------------
 src/murmur/ServerUser.h   | 16 ++--------------
 2 files changed, 9 insertions(+), 39 deletions(-)

diff --git a/src/murmur/ServerUser.cpp b/src/murmur/ServerUser.cpp
index 18db498e5..121b75c0b 100644
--- a/src/murmur/ServerUser.cpp
+++ b/src/murmur/ServerUser.cpp
@@ -112,32 +112,14 @@ int BandwidthRecord::bandwidth() const {
 	return static_cast<int>((sum * 1000000ULL) / elapsed);
 }
 
-#if __cplusplus > 199711LL
-
-inline static
-time_point now() {
-	return std::chrono::steady_clock::now();
+inline static QTime now() {
+	return QTime::currentTime();
 }
 
-inline static
-unsigned long millisecondsBetween(time_point start, time_point end) {
-	return std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+inline static int millisecondsBetween(const QTime &start, const QTime &end) {
+	return start.msecsTo(end);
 }
 
-#else
-
-inline static
-time_point now() {
-	return clock();
-}
-
-inline static
-unsigned long millisecondsBetween(time_point start, time_point end) {
-	return 1000 * (end - start) / CLOCKS_PER_SEC;
-}
-
-#endif
-
 // Rate limiting: burst up to 5, 1 message per sec limit over longer time
 LeakyBucket::LeakyBucket(unsigned int tokensPerSec, unsigned int maxTokens) : tokensPerSec(tokensPerSec), maxTokens(maxTokens), currentTokens(0) {
 	lastUpdate = now();
@@ -145,10 +127,10 @@ LeakyBucket::LeakyBucket(unsigned int tokensPerSec, unsigned int maxTokens) : to
 
 bool LeakyBucket::ratelimit(int tokens) {
 	// First remove tokens we leaked over time
-	time_point tnow = now();
-	long ms = millisecondsBetween(lastUpdate, tnow);
+	const QTime tnow = now();
+	const long ms = millisecondsBetween(lastUpdate, tnow);
 
-	long drainTokens = (ms * tokensPerSec) / 1000;
+	const long drainTokens = (ms * tokensPerSec) / 1000;
 
 	// Prevent constant starvation due to too many updates
 	if (drainTokens > 0) {
diff --git a/src/murmur/ServerUser.h b/src/murmur/ServerUser.h
index 36ba8d8da..09dee4dcb 100644
--- a/src/murmur/ServerUser.h
+++ b/src/murmur/ServerUser.h
@@ -7,6 +7,7 @@
 #define MUMBLE_MURMUR_SERVERUSER_H_
 
 #include <QtCore/QStringList>
+#include <QtCore/QTime>
 
 #ifdef Q_OS_UNIX
 #include <sys/socket.h>
@@ -14,13 +15,6 @@
 #include <winsock2.h>
 #endif
 
-// <chrono> was introduced in C++11
-#if __cplusplus > 199711LL
-#include <chrono>
-#else
-#include <ctime>
-#endif
-
 #include "Connection.h"
 #include "Timer.h"
 #include "User.h"
@@ -62,18 +56,12 @@ struct WhisperTarget {
 
 class Server;
 
-#if __cplusplus > 199711L
-        typedef std::chrono::time_point<std::chrono::steady_clock> time_point;
-#else
-        typedef clock_t time_point;
-#endif
-
 // Simple algorithm for rate limiting
 class LeakyBucket {
 	private:
 		unsigned int tokensPerSec, maxTokens;
 		long currentTokens;
-		time_point lastUpdate;
+		QTime lastUpdate;
 
 	public:
 		// Returns true if packets should be dropped