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platform-external-webrtc/rtc_base/numerics/moving_average.h
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

64 lines
2.0 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.
*/
#ifndef RTC_BASE_NUMERICS_MOVING_AVERAGE_H_
#define RTC_BASE_NUMERICS_MOVING_AVERAGE_H_
#include <vector>
#include "absl/types/optional.h"
namespace rtc {
// Calculates average over fixed size window. If there are less than window
// size elements, calculates average of all inserted so far elements.
//
class MovingAverage {
public:
// Maximum supported window size is 2^32 - 1.
explicit MovingAverage(size_t window_size);
~MovingAverage();
// MovingAverage is neither copyable nor movable.
MovingAverage(const MovingAverage&) = delete;
MovingAverage& operator=(const MovingAverage&) = delete;
// Adds new sample. If the window is full, the oldest element is pushed out.
void AddSample(int sample);
// Returns rounded down average of last |window_size| elements or all
// elements if there are not enough of them. Returns nullopt if there were
// no elements added.
absl::optional<int> GetAverageRoundedDown() const;
// Same as above but rounded to the closest integer.
absl::optional<int> GetAverageRoundedToClosest() const;
// Returns unrounded average over the window.
absl::optional<double> GetUnroundedAverage() const;
// Resets to the initial state before any elements were added.
void Reset();
// Returns number of elements in the window.
size_t Size() const;
private:
// Total number of samples added to the class since last reset.
size_t count_ = 0;
// Sum of the samples in the moving window.
int64_t sum_ = 0;
// Circular buffer for all the samples in the moving window.
// Size is always |window_size|
std::vector<int> history_;
};
} // namespace rtc
#endif // RTC_BASE_NUMERICS_MOVING_AVERAGE_H_