webrtc/rtc_base/numerics/moving_average.cc
Ilya Nikolaevskiy 26341990a1 Move MovingAverage to rtc_base/numerics and update it.
This utility class is needed in rtcp_rtp. Instead of reimplementing it
again, the existing class is moved to rtc_base, cleaned from unused
features and extended as required for the new usage.

Bug: webrtc:9914
Change-Id: I3b0d83d08d8fa5e1384b4721a93c6a90781948fd
Reviewed-on: https://webrtc-review.googlesource.com/c/109081
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25498}
2018-11-05 13:02:29 +00:00

60 lines
1.5 KiB
C++

/*
* Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "rtc_base/numerics/moving_average.h"
#include <algorithm>
#include "rtc_base/checks.h"
namespace rtc {
MovingAverage::MovingAverage(size_t window_size) : history_(window_size, 0) {
// Limit window size to avoid overflow.
RTC_DCHECK_LE(window_size, (int64_t{1} << 32) - 1);
}
MovingAverage::~MovingAverage() = default;
void MovingAverage::AddSample(int sample) {
count_++;
size_t index = count_ % history_.size();
if (count_ > history_.size())
sum_ -= history_[index];
sum_ += sample;
history_[index] = sample;
}
absl::optional<int> MovingAverage::GetAverageRoundedDown() const {
if (count_ == 0)
return absl::nullopt;
return sum_ / Size();
}
absl::optional<int> MovingAverage::GetAverageRoundedToClosest() const {
if (count_ == 0)
return absl::nullopt;
return (sum_ + Size() / 2) / Size();
}
absl::optional<double> MovingAverage::GetUnroundedAverage() const {
if (count_ == 0)
return absl::nullopt;
return sum_ / static_cast<double>(Size());
}
void MovingAverage::Reset() {
count_ = 0;
sum_ = 0;
}
size_t MovingAverage::Size() const {
return std::min(count_, history_.size());
}
} // namespace rtc