webrtc_m130/webrtc/rtc_base/ratetracker.h
Henrik Kjellander c03627683f Reland "Move webrtc/{base => rtc_base}" (https://codereview.webrtc.org/2877023002)
Reland the base->rtc_base without adding stub headers (will be
done in follow-up CL). This preserves git blame history of all files.

BUG=webrtc:7634
NOTRY=True
TBR=kwiberg@webrtc.org

Change-Id: Iea3bb6f3f67b8374c96337b63e8f5aa3e6181012
Reviewed-on: https://chromium-review.googlesource.com/554611
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18821}
2017-06-29 06:04:25 +00:00

70 lines
2.2 KiB
C++

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