1 // Copyright (c) 2011 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 #include "remoting/base/rate_counter.h" 6 7 #include "base/logging.h" 8 9 namespace remoting { 10 11 RateCounter::RateCounter(base::TimeDelta time_window) 12 : time_window_(time_window), 13 sum_(0) { 14 DCHECK_GT(time_window.InMilliseconds(), 0); 15 } 16 17 RateCounter::~RateCounter() { 18 } 19 20 void RateCounter::Record(int64 value) { 21 DCHECK(CalledOnValidThread()); 22 23 base::Time current_time = CurrentTime(); 24 EvictOldDataPoints(current_time); 25 sum_ += value; 26 data_points_.push(std::make_pair(current_time, value)); 27 } 28 29 double RateCounter::Rate() { 30 DCHECK(CalledOnValidThread()); 31 32 EvictOldDataPoints(CurrentTime()); 33 return sum_ / time_window_.InSecondsF(); 34 } 35 36 void RateCounter::SetCurrentTimeForTest(base::Time current_time) { 37 DCHECK(CalledOnValidThread()); 38 DCHECK(current_time >= current_time_for_test_); 39 40 current_time_for_test_ = current_time; 41 } 42 43 void RateCounter::EvictOldDataPoints(base::Time current_time) { 44 // Remove data points outside of the window. 45 base::Time window_start = current_time - time_window_; 46 47 while (!data_points_.empty()) { 48 if (data_points_.front().first > window_start) 49 break; 50 51 sum_ -= data_points_.front().second; 52 data_points_.pop(); 53 } 54 } 55 56 base::Time RateCounter::CurrentTime() const { 57 if (current_time_for_test_ == base::Time()) 58 return base::Time::Now(); 59 return current_time_for_test_; 60 } 61 62 } // namespace remoting 63
