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// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <vector>
#include "base/basictypes.h"
#include "base/time.h"
#include "cobalt/media/base/media_export.h"
#include "starboard/types.h"
namespace cobalt {
namespace media {
// Simple class for calculating a moving average of fixed size.
class MEDIA_EXPORT MovingAverage {
// Creates a MovingAverage instance with space for |depth| samples.
explicit MovingAverage(size_t depth);
// Adds a new sample to the average; replaces the oldest sample if |depth_|
// has been exceeded. Updates |total_| to the new sum of values.
void AddSample(base::TimeDelta sample);
// Returns the current average of all held samples.
base::TimeDelta Average() const;
// Returns the standard deviation of all held samples.
base::TimeDelta Deviation() const;
// Resets the state of the class to its initial post-construction state.
void Reset();
size_t count() const { return count_; }
// Maximum number of elements allowed in the average.
const size_t depth_;
// Number of elements seen thus far.
uint64_t count_;
std::vector<base::TimeDelta> samples_;
base::TimeDelta total_;
uint64_t square_sum_us_;
} // namespace media
} // namespace cobalt