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/*
* Copyright (c) 2016 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 "test/drifting_clock.h"
#include <cstdint>
#include "api/units/time_delta.h"
#include "api/units/timestamp.h"
#include "rtc_base/checks.h"
#include "system_wrappers/include/clock.h"
#include "system_wrappers/include/ntp_time.h"
namespace webrtc {
namespace test {
constexpr float DriftingClock::kNoDrift;
DriftingClock::DriftingClock(Clock* clock, float speed)
: clock_(clock), drift_(speed - 1.0f), start_time_(clock_->CurrentTime()) {
RTC_CHECK(clock);
RTC_CHECK_GT(speed, 0.0f);
}
TimeDelta DriftingClock::Drift() const {
auto now = clock_->CurrentTime();
RTC_DCHECK_GE(now, start_time_);
return (now - start_time_) * drift_;
}
Timestamp DriftingClock::Drift(Timestamp timestamp) const {
return timestamp + Drift() / 1000.;
}
NtpTime DriftingClock::Drift(NtpTime ntp_time) const {
// NTP precision is 1/2^32 seconds, i.e. 2^32 ntp fractions = 1 second.
const double kNtpFracPerMicroSecond = 4294.967296; // = 2^32 / 10^6
uint64_t total_fractions = static_cast<uint64_t>(ntp_time);
total_fractions += Drift().us() * kNtpFracPerMicroSecond;
return NtpTime(total_fractions);
}
} // namespace test
} // namespace webrtc
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