diff options
Diffstat (limited to 'third_party/libwebrtc/rtc_base/time_utils.cc')
-rw-r--r-- | third_party/libwebrtc/rtc_base/time_utils.cc | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/time_utils.cc b/third_party/libwebrtc/rtc_base/time_utils.cc new file mode 100644 index 0000000000..96282f06cf --- /dev/null +++ b/third_party/libwebrtc/rtc_base/time_utils.cc @@ -0,0 +1,270 @@ +/* + * Copyright 2004 The WebRTC Project Authors. All rights reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#include <stdint.h> + +#if defined(WEBRTC_POSIX) +#include <sys/time.h> +#endif + +#if defined(WEBRTC_WIN) +#include <sys/timeb.h> +#endif + +#include "rtc_base/checks.h" +#include "rtc_base/numerics/safe_conversions.h" +#include "rtc_base/system_time.h" +#include "rtc_base/time_utils.h" + +namespace rtc { + +ClockInterface* g_clock = nullptr; + +ClockInterface* SetClockForTesting(ClockInterface* clock) { + ClockInterface* prev = g_clock; + g_clock = clock; + return prev; +} + +ClockInterface* GetClockForTesting() { + return g_clock; +} + +#if defined(WINUWP) + +namespace { + +class TimeHelper final { + public: + TimeHelper(const TimeHelper&) = delete; + + // Resets the clock based upon an NTP server. This routine must be called + // prior to the main system start-up to ensure all clocks are based upon + // an NTP server time if NTP synchronization is required. No critical + // section is used thus this method must be called prior to any clock + // routines being used. + static void SyncWithNtp(int64_t ntp_server_time_ms) { + auto& singleton = Singleton(); + TIME_ZONE_INFORMATION time_zone; + GetTimeZoneInformation(&time_zone); + int64_t time_zone_bias_ns = + rtc::dchecked_cast<int64_t>(time_zone.Bias) * 60 * 1000 * 1000 * 1000; + singleton.app_start_time_ns_ = + (ntp_server_time_ms - kNTPTimeToUnixTimeEpochOffset) * 1000000 - + time_zone_bias_ns; + singleton.UpdateReferenceTime(); + } + + // Returns the number of nanoseconds that have passed since unix epoch. + static int64_t TicksNs() { + auto& singleton = Singleton(); + int64_t result = 0; + LARGE_INTEGER qpcnt; + QueryPerformanceCounter(&qpcnt); + result = rtc::dchecked_cast<int64_t>( + (rtc::dchecked_cast<uint64_t>(qpcnt.QuadPart) * 100000 / + rtc::dchecked_cast<uint64_t>(singleton.os_ticks_per_second_)) * + 10000); + result = singleton.app_start_time_ns_ + result - + singleton.time_since_os_start_ns_; + return result; + } + + private: + TimeHelper() { + TIME_ZONE_INFORMATION time_zone; + GetTimeZoneInformation(&time_zone); + int64_t time_zone_bias_ns = + rtc::dchecked_cast<int64_t>(time_zone.Bias) * 60 * 1000 * 1000 * 1000; + FILETIME ft; + // This will give us system file in UTC format. + GetSystemTimeAsFileTime(&ft); + LARGE_INTEGER li; + li.HighPart = ft.dwHighDateTime; + li.LowPart = ft.dwLowDateTime; + + app_start_time_ns_ = (li.QuadPart - kFileTimeToUnixTimeEpochOffset) * 100 - + time_zone_bias_ns; + + UpdateReferenceTime(); + } + + static TimeHelper& Singleton() { + static TimeHelper singleton; + return singleton; + } + + void UpdateReferenceTime() { + LARGE_INTEGER qpfreq; + QueryPerformanceFrequency(&qpfreq); + os_ticks_per_second_ = rtc::dchecked_cast<int64_t>(qpfreq.QuadPart); + + LARGE_INTEGER qpcnt; + QueryPerformanceCounter(&qpcnt); + time_since_os_start_ns_ = rtc::dchecked_cast<int64_t>( + (rtc::dchecked_cast<uint64_t>(qpcnt.QuadPart) * 100000 / + rtc::dchecked_cast<uint64_t>(os_ticks_per_second_)) * + 10000); + } + + private: + static constexpr uint64_t kFileTimeToUnixTimeEpochOffset = + 116444736000000000ULL; + static constexpr uint64_t kNTPTimeToUnixTimeEpochOffset = 2208988800000L; + + // The number of nanoseconds since unix system epoch + int64_t app_start_time_ns_; + // The number of nanoseconds since the OS started + int64_t time_since_os_start_ns_; + // The OS calculated ticks per second + int64_t os_ticks_per_second_; +}; + +} // namespace + +void SyncWithNtp(int64_t time_from_ntp_server_ms) { + TimeHelper::SyncWithNtp(time_from_ntp_server_ms); +} + +int64_t WinUwpSystemTimeNanos() { + return TimeHelper::TicksNs(); +} + +#endif // defined(WINUWP) + +int64_t SystemTimeMillis() { + return static_cast<int64_t>(SystemTimeNanos() / kNumNanosecsPerMillisec); +} + +int64_t TimeNanos() { + if (g_clock) { + return g_clock->TimeNanos(); + } + return SystemTimeNanos(); +} + +uint32_t Time32() { + return static_cast<uint32_t>(TimeNanos() / kNumNanosecsPerMillisec); +} + +int64_t TimeMillis() { + return TimeNanos() / kNumNanosecsPerMillisec; +} + +int64_t TimeMicros() { + return TimeNanos() / kNumNanosecsPerMicrosec; +} + +int64_t TimeAfter(int64_t elapsed) { + RTC_DCHECK_GE(elapsed, 0); + return TimeMillis() + elapsed; +} + +int32_t TimeDiff32(uint32_t later, uint32_t earlier) { + return later - earlier; +} + +int64_t TimeDiff(int64_t later, int64_t earlier) { + return later - earlier; +} + +TimestampWrapAroundHandler::TimestampWrapAroundHandler() + : last_ts_(0), num_wrap_(-1) {} + +int64_t TimestampWrapAroundHandler::Unwrap(uint32_t ts) { + if (num_wrap_ == -1) { + last_ts_ = ts; + num_wrap_ = 0; + return ts; + } + + if (ts < last_ts_) { + if (last_ts_ >= 0xf0000000 && ts < 0x0fffffff) + ++num_wrap_; + } else if ((ts - last_ts_) > 0xf0000000) { + // Backwards wrap. Unwrap with last wrap count and don't update last_ts_. + return ts + (num_wrap_ - 1) * (int64_t{1} << 32); + } + + last_ts_ = ts; + return ts + (num_wrap_ << 32); +} + +int64_t TmToSeconds(const tm& tm) { + static short int mdays[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; + static short int cumul_mdays[12] = {0, 31, 59, 90, 120, 151, + 181, 212, 243, 273, 304, 334}; + int year = tm.tm_year + 1900; + int month = tm.tm_mon; + int day = tm.tm_mday - 1; // Make 0-based like the rest. + int hour = tm.tm_hour; + int min = tm.tm_min; + int sec = tm.tm_sec; + + bool expiry_in_leap_year = + (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)); + + if (year < 1970) + return -1; + if (month < 0 || month > 11) + return -1; + if (day < 0 || day >= mdays[month] + (expiry_in_leap_year && month == 2 - 1)) + return -1; + if (hour < 0 || hour > 23) + return -1; + if (min < 0 || min > 59) + return -1; + if (sec < 0 || sec > 59) + return -1; + + day += cumul_mdays[month]; + + // Add number of leap days between 1970 and the expiration year, inclusive. + day += ((year / 4 - 1970 / 4) - (year / 100 - 1970 / 100) + + (year / 400 - 1970 / 400)); + + // We will have added one day too much above if expiration is during a leap + // year, and expiration is in January or February. + if (expiry_in_leap_year && month <= 2 - 1) // `month` is zero based. + day -= 1; + + // Combine all variables into seconds from 1970-01-01 00:00 (except `month` + // which was accumulated into `day` above). + return (((static_cast<int64_t>(year - 1970) * 365 + day) * 24 + hour) * 60 + + min) * + 60 + + sec; +} + +int64_t TimeUTCMicros() { + if (g_clock) { + return g_clock->TimeNanos() / kNumNanosecsPerMicrosec; + } +#if defined(WEBRTC_POSIX) + struct timeval time; + gettimeofday(&time, nullptr); + // Convert from second (1.0) and microsecond (1e-6). + return (static_cast<int64_t>(time.tv_sec) * rtc::kNumMicrosecsPerSec + + time.tv_usec); + +#elif defined(WEBRTC_WIN) + struct _timeb time; + _ftime(&time); + // Convert from second (1.0) and milliseconds (1e-3). + return (static_cast<int64_t>(time.time) * rtc::kNumMicrosecsPerSec + + static_cast<int64_t>(time.millitm) * rtc::kNumMicrosecsPerMillisec); +#endif +} + +int64_t TimeUTCMillis() { + return TimeUTCMicros() / kNumMicrosecsPerMillisec; +} + +} // namespace rtc |