Tweaked version of BBR for WebRTC.

webrtc/modules/pacing/bbr_paced_sender.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_PACING_BBR_PACED_SENDER_H_

[philipel, 2017/08/17 12:52:26]

This file should be moved. I think
webrtc/modules/remote_bitrate_estimator/test/pacers would be a good place.

[gnish1, 2017/08/17 15:37:48]

Done.

+#define WEBRTC_MODULES_PACING_BBR_PACED_SENDER_H_
+
+#include <list>
+#include <memory>
+
+#include "webrtc/modules/pacing/paced_sender.h"
+#include "webrtc/modules/pacing/pacer.h"
+
+namespace webrtc {
+class Clock;
+class RtcEventLog;
+namespace bbr_paced_sender {
+struct Packet;
+}  // namespace bbr_paced_sender
+class BbrPacedSender : public Pacer {
+ public:
+  BbrPacedSender(const Clock* clock,
+                 PacedSender::PacketSender* packet_sender,
+                 RtcEventLog* event_log);
+  ~BbrPacedSender() override;
+  void SetEstimatedBitrateAndCongestionWindow(
+      uint32_t bitrate_bps,
+      bool in_probe_rtt,
+      uint64_t congestion_window) override;
+  void SetMinBitrate(int min_send_bitrate_bps);
+  void InsertPacket(RtpPacketSender::Priority priority,
+                    uint32_t ssrc,
+                    uint16_t sequence_number,
+                    int64_t capture_time_ms,
+                    size_t bytes,
+                    bool retransmission) override;
+  int64_t TimeUntilNextProcess() override;
+  void OnBytesAcked(size_t bytes) override;
+  void Process() override;
+  bool TryToSendPacket(bbr_paced_sender::Packet* packet);
+
+ private:
+  const Clock* const clock_;
+  PacedSender::PacketSender* const packet_sender_;
+  uint32_t estimated_bitrate_bps_;
+  uint32_t min_send_bitrate_kbps_;
+  uint32_t pacing_bitrate_kbps_;
+  int64_t time_last_update_us_;
+  int64_t time_last_update_ms_;
+  int64_t next_packet_send_time_;
+  float extra_time_;

[philipel, 2017/08/17 12:52:26]

Could you come up with a better name than |extra_time_|, it's not particularly
clear. 

[gnish1, 2017/08/17 15:37:48]

Done.

+  std::list<bbr_paced_sender::Packet*> packets_;
+  size_t data_inflight_;
+  size_t congestion_window_;

[philipel, 2017/08/17 12:52:26]

Use the already existing congestion window class instead of re-implementing it
here.

[gnish1, 2017/08/17 15:37:48]

Done.

+  bool in_probe_rtt_;
+};
+}  // namespace webrtc
+#endif  // WEBRTC_MODULES_PACING_BBR_PACED_SENDER_H_