michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_PROFILER_TRACKED_TIME_H_
michael@0: #define BASE_PROFILER_TRACKED_TIME_H_
michael@0: 
michael@0: 
michael@0: #include "base/base_export.h"
michael@0: #include "base/basictypes.h"
michael@0: #include "base/time/time.h"
michael@0: 
michael@0: namespace tracked_objects {
michael@0: 
michael@0: //------------------------------------------------------------------------------
michael@0: 
michael@0: // TimeTicks maintains a wasteful 64 bits of data (we need less than 32), and on
michael@0: // windows, a 64 bit timer is expensive to even obtain. We use a simple
michael@0: // millisecond counter for most of our time values, as well as millisecond units
michael@0: // of duration between those values.  This means we can only handle durations
michael@0: // up to 49 days (range), or 24 days (non-negative time durations).
michael@0: // We only define enough methods to service the needs of the tracking classes,
michael@0: // and our interfaces are modeled after what TimeTicks and TimeDelta use (so we
michael@0: // can swap them into place if we want to use the "real" classes).
michael@0: 
michael@0: class BASE_EXPORT Duration {  // Similar to base::TimeDelta.
michael@0:  public:
michael@0:   Duration();
michael@0: 
michael@0:   Duration& operator+=(const Duration& other);
michael@0:   Duration operator+(const Duration& other) const;
michael@0: 
michael@0:   bool operator==(const Duration& other) const;
michael@0:   bool operator!=(const Duration& other) const;
michael@0:   bool operator>(const Duration& other) const;
michael@0: 
michael@0:   static Duration FromMilliseconds(int ms);
michael@0: 
michael@0:   int32 InMilliseconds() const;
michael@0: 
michael@0:  private:
michael@0:   friend class TrackedTime;
michael@0:   explicit Duration(int32 duration);
michael@0: 
michael@0:   // Internal time is stored directly in milliseconds.
michael@0:   int32 ms_;
michael@0: };
michael@0: 
michael@0: class BASE_EXPORT TrackedTime {  // Similar to base::TimeTicks.
michael@0:  public:
michael@0:   TrackedTime();
michael@0:   explicit TrackedTime(const base::TimeTicks& time);
michael@0: 
michael@0:   static TrackedTime Now();
michael@0:   Duration operator-(const TrackedTime& other) const;
michael@0:   TrackedTime operator+(const Duration& other) const;
michael@0:   bool is_null() const;
michael@0: 
michael@0:   static TrackedTime FromMilliseconds(int32 ms) { return TrackedTime(ms); }
michael@0: 
michael@0:  private:
michael@0:   friend class Duration;
michael@0:   explicit TrackedTime(int32 ms);
michael@0: 
michael@0:   // Internal duration is stored directly in milliseconds.
michael@0:   uint32 ms_;
michael@0: };
michael@0: 
michael@0: }  // namespace tracked_objects
michael@0: 
michael@0: #endif  // BASE_PROFILER_TRACKED_TIME_H_