1/*
2 *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#ifndef WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_RATE_STATISTICS_H_
12#define WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_RATE_STATISTICS_H_
13
14#include "webrtc/system_wrappers/interface/scoped_ptr.h"
15#include "webrtc/typedefs.h"
16
17namespace webrtc {
18
19class RateStatistics {
20 public:
21  // window_size = window size in ms for the rate estimation
22  // scale = coefficient to convert counts/ms to desired units,
23  //         ex: if counts represents bytes, use 8*1000 to go to bits/s
24  RateStatistics(uint32_t window_size_ms, float scale);
25  ~RateStatistics();
26
27  void Reset();
28  void Update(uint32_t count, int64_t now_ms);
29  uint32_t Rate(int64_t now_ms);
30
31 private:
32  void EraseOld(int64_t now_ms);
33
34  // Counters are kept in buckets (circular buffer), with one bucket
35  // per millisecond.
36  const int num_buckets_;
37  scoped_ptr<uint32_t[]> buckets_;
38
39  // Total count recorded in buckets.
40  uint32_t accumulated_count_;
41
42  // Oldest time recorded in buckets.
43  int64_t oldest_time_;
44
45  // Bucket index of oldest counter recorded in buckets.
46  int oldest_index_;
47
48  // To convert counts/ms to desired units
49  const float scale_;
50};
51}  // namespace webrtc
52
53#endif  // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_RATE_STATISTICS_H_
54