1 /* 2 * Copyright (c) 2016 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #include "test/drifting_clock.h" 12 #include "rtc_base/checks.h" 13 14 namespace webrtc { 15 namespace test { 16 const float DriftingClock::kDoubleSpeed = 2.0f; 17 const float DriftingClock::kNoDrift = 1.0f; 18 const float DriftingClock::kHalfSpeed = 0.5f; 19 DriftingClock(Clock * clock,float speed)20DriftingClock::DriftingClock(Clock* clock, float speed) 21 : clock_(clock), 22 drift_(speed - 1.0f), 23 start_time_(clock_->TimeInMicroseconds()) { 24 RTC_CHECK(clock); 25 RTC_CHECK_GT(speed, 0.0f); 26 } 27 Drift() const28float DriftingClock::Drift() const { 29 int64_t now = clock_->TimeInMicroseconds(); 30 RTC_DCHECK_GE(now, start_time_); 31 return (now - start_time_) * drift_; 32 } 33 TimeInMilliseconds() const34int64_t DriftingClock::TimeInMilliseconds() const { 35 return clock_->TimeInMilliseconds() + Drift() / 1000.; 36 } 37 TimeInMicroseconds() const38int64_t DriftingClock::TimeInMicroseconds() const { 39 return clock_->TimeInMicroseconds() + Drift(); 40 } 41 CurrentNtpTime() const42NtpTime DriftingClock::CurrentNtpTime() const { 43 // NTP precision is 1/2^32 seconds, i.e. 2^32 ntp fractions = 1 second. 44 const double kNtpFracPerMicroSecond = 4294.967296; // = 2^32 / 10^6 45 46 NtpTime ntp = clock_->CurrentNtpTime(); 47 uint64_t total_fractions = static_cast<uint64_t>(ntp); 48 total_fractions += Drift() * kNtpFracPerMicroSecond; 49 return NtpTime(total_fractions); 50 } 51 CurrentNtpInMilliseconds() const52int64_t DriftingClock::CurrentNtpInMilliseconds() const { 53 return clock_->CurrentNtpInMilliseconds() + Drift() / 1000.; 54 } 55 } // namespace test 56 } // namespace webrtc 57