1 /* 2 * Copyright (c) 2018 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #include "rtc_base/numerics/moving_average.h" 12 13 #include <algorithm> 14 15 #include "rtc_base/checks.h" 16 17 namespace rtc { 18 MovingAverage(size_t window_size)19MovingAverage::MovingAverage(size_t window_size) : history_(window_size, 0) { 20 // Limit window size to avoid overflow. 21 RTC_DCHECK_LE(window_size, (int64_t{1} << 32) - 1); 22 } 23 MovingAverage::~MovingAverage() = default; 24 AddSample(int sample)25void MovingAverage::AddSample(int sample) { 26 count_++; 27 size_t index = count_ % history_.size(); 28 if (count_ > history_.size()) 29 sum_ -= history_[index]; 30 sum_ += sample; 31 history_[index] = sample; 32 } 33 GetAverageRoundedDown() const34absl::optional<int> MovingAverage::GetAverageRoundedDown() const { 35 if (count_ == 0) 36 return absl::nullopt; 37 return sum_ / Size(); 38 } 39 GetAverageRoundedToClosest() const40absl::optional<int> MovingAverage::GetAverageRoundedToClosest() const { 41 if (count_ == 0) 42 return absl::nullopt; 43 return (sum_ + Size() / 2) / Size(); 44 } 45 GetUnroundedAverage() const46absl::optional<double> MovingAverage::GetUnroundedAverage() const { 47 if (count_ == 0) 48 return absl::nullopt; 49 return sum_ / static_cast<double>(Size()); 50 } 51 Reset()52void MovingAverage::Reset() { 53 count_ = 0; 54 sum_ = 0; 55 } 56 Size() const57size_t MovingAverage::Size() const { 58 return std::min(count_, history_.size()); 59 } 60 } // namespace rtc 61