net/quic/congestion_control/prr_sender.h

   1 // Copyright (c) 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5 // Implements Proportional Rate Reduction (PRR) per RFC 6937.
   6
   7 #ifndef NET_QUIC_CONGESTION_CONTROL_PRR_SENDER_H_
   8 #define NET_QUIC_CONGESTION_CONTROL_PRR_SENDER_H_
   9
  10 #include "net/quic/quic_bandwidth.h"
  11 #include "net/quic/quic_time.h"
  12
  13 namespace net {
  14
  15 class NET_EXPORT_PRIVATE PrrSender {
  16  public:
  17   PrrSender();
  18   // OnPacketLost should be called on the first loss that triggers a recovery
  19   // period and all other methods in this class should only be called when in
  20   // recovery.
  21   void OnPacketLost(QuicByteCount bytes_in_flight);
  22   void OnPacketSent(QuicByteCount sent_bytes);
  23   void OnPacketAcked(QuicByteCount acked_bytes);
  24   QuicTime::Delta TimeUntilSend(QuicByteCount congestion_window,
  25                                 QuicByteCount bytes_in_flight,
  26                                 QuicByteCount slowstart_threshold) const;
  27
  28  private:
  29   // Bytes sent and acked since the last loss event.
  30   // |bytes_sent_since_loss_| is the same as "prr_out_" in RFC 6937,
  31   // and |bytes_delivered_since_loss_| is the same as "prr_delivered_".
  32   QuicByteCount bytes_sent_since_loss_;
  33   QuicByteCount bytes_delivered_since_loss_;
  34   size_t ack_count_since_loss_;
  35
  36   // The congestion window before the last loss event.
  37   QuicByteCount bytes_in_flight_before_loss_;
  38 };
  39
  40 }  // namespace net
  41
  42 #endif  // NET_QUIC_CONGESTION_CONTROL_PRR_SENDER_H_