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// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "components/network_time/time_tracker/time_tracker.h"
#include "base/logging.h"
namespace {
// Amount of divergence allowed between wall clock and tick clock.
const uint32_t kClockDivergenceSeconds = 60;
} // namespace
namespace network_time {
TimeTracker::TimeTracker(const base::Time& system_time,
const base::TimeTicks& system_ticks,
const base::Time& time,
const base::TimeDelta& uncertainty)
: state_{system_time, system_ticks, time, uncertainty} {}
bool TimeTracker::GetTime(const base::Time& system_time,
const base::TimeTicks& system_ticks,
base::Time* time,
base::TimeDelta* uncertainty) const {
base::TimeDelta tick_delta = system_ticks - state_.system_ticks;
base::TimeDelta time_delta = system_time - state_.system_time;
if (time_delta.InMilliseconds() < 0) {
DVLOG(1) << "Time unavailable due to wall clock running backward";
return false;
}
base::TimeDelta divergence = tick_delta - time_delta;
if (divergence.magnitude() > base::Seconds(kClockDivergenceSeconds)) {
DVLOG(1) << "Time unavailable due to clocks diverging";
return false;
}
*time = state_.known_time + tick_delta;
if (uncertainty) {
*uncertainty = state_.uncertainty + divergence;
}
return true;
}
} // namespace network_time
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