70 lines
2.2 KiB
C
70 lines
2.2 KiB
C
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/*
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* Copyright 2015 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 WEBRTC_BASE_RATETRACKER_H_
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#define WEBRTC_BASE_RATETRACKER_H_
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#include <stdlib.h>
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#include "webrtc/base/basictypes.h"
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namespace rtc {
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// Computes units per second over a given interval by tracking the units over
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// each bucket of a given size and calculating the instantaneous rate assuming
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// that over each bucket the rate was constant.
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class RateTracker {
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public:
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RateTracker(int64_t bucket_milliseconds, size_t bucket_count);
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virtual ~RateTracker();
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// Computes the average rate over the most recent interval_milliseconds,
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// or if the first sample was added within this period, computes the rate
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// since the first sample was added.
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double ComputeRateForInterval(int64_t interval_milliseconds) const;
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// Computes the average rate over the rate tracker's recording interval
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// of bucket_milliseconds * bucket_count.
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double ComputeRate() const {
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return ComputeRateForInterval(bucket_milliseconds_ *
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static_cast<int64_t>(bucket_count_));
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}
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// Computes the average rate since the first sample was added to the
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// rate tracker.
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double ComputeTotalRate() const;
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// The total number of samples added.
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size_t TotalSampleCount() const;
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// Reads the current time in order to determine the appropriate bucket for
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// these samples, and increments the count for that bucket by sample_count.
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void AddSamples(size_t sample_count);
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protected:
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// overrideable for tests
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virtual int64_t Time() const;
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private:
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void EnsureInitialized();
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size_t NextBucketIndex(size_t bucket_index) const;
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const int64_t bucket_milliseconds_;
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const size_t bucket_count_;
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size_t* sample_buckets_;
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size_t total_sample_count_;
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size_t current_bucket_;
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int64_t bucket_start_time_milliseconds_;
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int64_t initialization_time_milliseconds_;
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};
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} // namespace rtc
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#endif // WEBRTC_BASE_RATETRACKER_H_
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