Mypal/dom/performance/PerformanceService.h

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2019-03-11 03:26:37 -07:00
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef dom_performance_PerformanceService_h
#define dom_performance_PerformanceService_h
#include "mozilla/TimeStamp.h"
#include "nsCOMPtr.h"
#include "nsDOMNavigationTiming.h"
namespace mozilla {
namespace dom {
// This class is thread-safe.
// We use this singleton for having the correct value of performance.timeOrigin.
// This value must be calculated on top of the pair:
// - mCreationTimeStamp (monotonic clock)
// - mCreationEpochTime (unix epoch time)
// These 2 values must be taken "at the same time" in order to be used
// correctly.
class PerformanceService
{
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(PerformanceService)
static PerformanceService*
GetOrCreate();
DOMHighResTimeStamp
TimeOrigin(const TimeStamp& aCreationTimeStamp) const;
private:
PerformanceService();
~PerformanceService() = default;
TimeStamp mCreationTimeStamp;
PRTime mCreationEpochTime;
};
} // dom namespace
} // mozilla namespace
#endif // dom_performance_PerformanceService_h