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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_PROFILER_TRACKED_TIME_H_
#define BASE_PROFILER_TRACKED_TIME_H_
#include "base/base_export.h"
#include "base/basictypes.h"
#include "base/time/time.h"
namespace tracked_objects {
//------------------------------------------------------------------------------
// TimeTicks maintains a wasteful 64 bits of data (we need less than 32), and on
// windows, a 64 bit timer is expensive to even obtain. We use a simple
// millisecond counter for most of our time values, as well as millisecond units
// of duration between those values. This means we can only handle durations
// up to 49 days (range), or 24 days (non-negative time durations).
// We only define enough methods to service the needs of the tracking classes,
// and our interfaces are modeled after what TimeTicks and TimeDelta use (so we
// can swap them into place if we want to use the "real" classes).
class BASE_EXPORT Duration { // Similar to base::TimeDelta.
public:
Duration();
Duration& operator+=(const Duration& other);
Duration operator+(const Duration& other) const;
bool operator==(const Duration& other) const;
bool operator!=(const Duration& other) const;
bool operator>(const Duration& other) const;
static Duration FromMilliseconds(int ms);
int32 InMilliseconds() const;
private:
friend class TrackedTime;
explicit Duration(int32 duration);
// Internal time is stored directly in milliseconds.
int32 ms_;
};
class BASE_EXPORT TrackedTime { // Similar to base::TimeTicks.
public:
TrackedTime();
explicit TrackedTime(const base::TimeTicks& time);
static TrackedTime Now();
Duration operator-(const TrackedTime& other) const;
TrackedTime operator+(const Duration& other) const;
bool is_null() const;
static TrackedTime FromMilliseconds(int32 ms) { return TrackedTime(ms); }
private:
friend class Duration;
explicit TrackedTime(int32 ms);
// Internal duration is stored directly in milliseconds.
uint32 ms_;
};
} // namespace tracked_objects
#endif // BASE_PROFILER_TRACKED_TIME_H_