tdesktop/Telegram/SourceFiles/base/unixtime.cpp

180 lines
3.9 KiB
C++

/*
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
*/
#include "base/unixtime.h"
#include "logs.h"
#include <QDateTime>
#include <QReadWriteLock>
#ifdef Q_OS_WIN
#elif defined Q_OS_MAC
#include <mach/mach_time.h>
#else
#include <time.h>
#endif
namespace base {
namespace unixtime {
namespace {
std::atomic<bool> ValueUpdated/* = false*/;
std::atomic<TimeId> ValueShift/* = 0*/;
std::atomic<bool> HttpValueValid/* = false*/;
std::atomic<TimeId> HttpValueShift/* = 0*/;
class MsgIdManager {
public:
MsgIdManager();
void update();
[[nodiscard]] uint64 next();
private:
void initialize();
QReadWriteLock _lock;
uint64 _startId = 0;
std::atomic<uint32> _incrementedPart = 0;
uint64 _startCounter = 0;
uint64 _randomPart = 0;
float64 _multiplier = 0.;
};
MsgIdManager GlobalMsgIdManager;
[[nodiscard]] float64 GetMultiplier() {
// 0xFFFF0000 instead of 0x100000000 to make msgId grow slightly slower,
// than unixtime and we had time to reconfigure.
#ifdef Q_OS_WIN
LARGE_INTEGER li;
QueryPerformanceFrequency(&li);
return float64(0xFFFF0000L) / float64(li.QuadPart);
#elif defined Q_OS_MAC // Q_OS_WIN
mach_timebase_info_data_t tb = { 0, 0 };
mach_timebase_info(&tb);
const auto frequency = (float64(tb.numer) / tb.denom) / 1000000.;
return frequency * (float64(0xFFFF0000L) / 1000.);
#else // Q_OS_MAC || Q_OS_WIN
return float64(0xFFFF0000L) / 1000000000.;
#endif // Q_OS_MAC || Q_OS_WIN
}
[[nodiscard]] uint64 GetCounter() {
#ifdef Q_OS_WIN
LARGE_INTEGER li;
QueryPerformanceCounter(&li);
return li.QuadPart;
#elif defined Q_OS_MAC // Q_OS_WIN
return mach_absolute_time();
#else // Q_OS_MAC || Q_OS_WIN
timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return 1000000000 * uint64(ts.tv_sec) + uint64(ts.tv_nsec);
#endif // Q_OS_MAC || Q_OS_WIN
}
MsgIdManager::MsgIdManager() {
auto generator = std::mt19937(std::random_device()());
auto distribution = std::uniform_int_distribution<uint32>();
_randomPart = distribution(generator);
_multiplier = GetMultiplier();
initialize();
srand(uint32(_startCounter & 0xFFFFFFFFUL));
}
void MsgIdManager::update() {
QWriteLocker lock(&_lock);
initialize();
}
void MsgIdManager::initialize() {
_startCounter = GetCounter();
_startId = ((uint64(uint32(now()))) << 32) | _randomPart;
}
uint64 MsgIdManager::next() {
const auto counter = GetCounter();
QReadLocker lock(&_lock);
const auto delta = (counter - _startCounter);
const auto result = _startId + (uint64)floor(delta * _multiplier);
lock.unlock();
return (result & ~0x03L) + (_incrementedPart += 4);
}
TimeId local() {
return (TimeId)time(nullptr);
}
} // namespace
TimeId now() {
return local() + ValueShift.load();
}
void update(TimeId now, bool force) {
if (force) {
DEBUG_LOG(("MTP Info: forcing client unixtime to %1"
).arg(now));
ValueUpdated = true;
} else {
auto expected = false;
if (!ValueUpdated.compare_exchange_strong(expected, true)) {
return;
}
DEBUG_LOG(("MTP Info: setting client unixtime to %1").arg(now));
}
const auto shift = now + 1 - local();
ValueShift = shift;
DEBUG_LOG(("MTP Info: now unixtimeDelta is %1").arg(shift));
HttpValueShift = 0;
HttpValueValid = false;
GlobalMsgIdManager.update();
}
QDateTime parse(TimeId value) {
return (value > 0)
? QDateTime::fromTime_t(value - ValueShift)
: QDateTime();
}
TimeId serialize(const QDateTime &date) {
return date.isNull() ? TimeId(0) : date.toTime_t() + ValueShift;
}
bool http_valid() {
return HttpValueValid;
}
TimeId http_now() {
return now() + HttpValueShift;
}
void http_update(TimeId now) {
HttpValueShift = now - base::unixtime::now();
HttpValueValid = true;
}
void http_invalidate() {
HttpValueValid = false;
}
uint64 mtproto_msg_id() {
return GlobalMsgIdManager.next();
}
} // namespace unixtime
} // namespace base