1// Copyright 2014 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef CAST_MEDIA_TEST_SKEWED_TICK_CLOCK_H 6#define CAST_MEDIA_TEST_SKEWED_TICK_CLOCK_H 7 8#include "base/time/tick_clock.h" 9#include "base/time/time.h" 10 11namespace media { 12namespace cast { 13namespace test { 14 15// Wraps a base::TickClock, and lets you change the speed and offset 16// of time compared to the wrapped clock. See SetSkew for how usage. 17class SkewedTickClock : public base::TickClock { 18 public: 19 // Does not take ownership of |clock_|. 20 explicit SkewedTickClock(base::TickClock* clock_); 21 // |skew| > 1.0 means clock runs faster. 22 // |offset| > 0 means clock returns times from the future. 23 // Note, |offset| is cumulative. 24 // Also note that changing the skew will never make the clock 25 // jump forwards or backwards, only changing the offset will 26 // do that. 27 void SetSkew(double skew, base::TimeDelta offset); 28 virtual base::TimeTicks NowTicks() OVERRIDE; 29 30 private: 31 base::TimeTicks SkewTicks(base::TimeTicks now); 32 base::TickClock* clock_; // Not owned. 33 double skew_; 34 base::TimeTicks last_skew_set_time_; 35 base::TimeTicks skew_clock_at_last_set_; 36 37 DISALLOW_COPY_AND_ASSIGN(SkewedTickClock); 38}; 39 40} // namespace test 41} // namespace cast 42} // namespace media 43 44#endif // CAST_MEDIA_TEST_SKEWED_TICK_CLOCK_H 45