modules/congestion_controller/acknowledge_bitrate_estimator.h

/*
 *  Copyright (c) 2017 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_MODULES_CONGESTION_CONTROLLER_ACKNOWLEDGE_BITRATE_ESTIMATOR_H_
#define WEBRTC_MODULES_CONGESTION_CONTROLLER_ACKNOWLEDGE_BITRATE_ESTIMATOR_H_

#include <vector>

#include "webrtc/base/optional.h"

namespace webrtc {

struct PacketFeedback;

// Computes a bayesian estimate of the throughput given acks containing
// the arrival time and payload size. Samples which are far from the current
// estimate or are based on few packets are given a smaller weight, as they
// are considered to be more likely to have been caused by, e.g., delay spikes
// unrelated to congestion.
class AcknowledgedBitrateEstimator {
 public:
  AcknowledgedBitrateEstimator();

  void IncomingPacketFeedbackVector(
      const std::vector<PacketFeedback>& packet_feedback_vector);
  rtc::Optional<uint32_t> bitrate_bps() const;

 private:
  void Update(int64_t now_ms, int bytes);
  float UpdateWindow(int64_t now_ms, int bytes, int rate_window_ms);

  int sum_;
  int64_t current_win_ms_;
  int64_t prev_time_ms_;
  float bitrate_estimate_;
  float bitrate_estimate_var_;
};

}  // namespace webrtc

#endif  // WEBRTC_MODULES_CONGESTION_CONTROLLER_ACKNOWLEDGE_BITRATE_ESTIMATOR_H_