67 lines
2.1 KiB
C
67 lines
2.1 KiB
C
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/*
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* Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef RTC_BASE_NUMERICS_MOVING_AVERAGE_H_
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#define RTC_BASE_NUMERICS_MOVING_AVERAGE_H_
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#include <stddef.h>
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#include <stdint.h>
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#include <vector>
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#include "absl/types/optional.h"
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namespace rtc {
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// Calculates average over fixed size window. If there are less than window
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// size elements, calculates average of all inserted so far elements.
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//
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class MovingAverage {
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public:
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// Maximum supported window size is 2^32 - 1.
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explicit MovingAverage(size_t window_size);
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~MovingAverage();
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// MovingAverage is neither copyable nor movable.
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MovingAverage(const MovingAverage&) = delete;
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MovingAverage& operator=(const MovingAverage&) = delete;
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// Adds new sample. If the window is full, the oldest element is pushed out.
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void AddSample(int sample);
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// Returns rounded down average of last |window_size| elements or all
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// elements if there are not enough of them. Returns nullopt if there were
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// no elements added.
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absl::optional<int> GetAverageRoundedDown() const;
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// Same as above but rounded to the closest integer.
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absl::optional<int> GetAverageRoundedToClosest() const;
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// Returns unrounded average over the window.
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absl::optional<double> GetUnroundedAverage() const;
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// Resets to the initial state before any elements were added.
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void Reset();
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// Returns number of elements in the window.
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size_t Size() const;
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private:
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// Total number of samples added to the class since last reset.
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size_t count_ = 0;
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// Sum of the samples in the moving window.
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int64_t sum_ = 0;
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// Circular buffer for all the samples in the moving window.
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// Size is always |window_size|
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std::vector<int> history_;
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};
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} // namespace rtc
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#endif // RTC_BASE_NUMERICS_MOVING_AVERAGE_H_
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