net/quic/congestion_control/tcp_loss_algorithm.h

   1 // Copyright 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 #ifndef NET_QUIC_CONGESTION_CONTROL_TCP_LOSS_ALGORITHM_H_
   6 #define NET_QUIC_CONGESTION_CONTROL_TCP_LOSS_ALGORITHM_H_
   7
   8 #include <algorithm>
   9 #include <map>
  10
  11 #include "base/basictypes.h"
  12 #include "net/quic/congestion_control/loss_detection_interface.h"
  13 #include "net/quic/quic_protocol.h"
  14 #include "net/quic/quic_time.h"
  15 #include "net/quic/quic_unacked_packet_map.h"
  16
  17 namespace net {
  18
  19 // Class which implement's TCP's approach of detecting loss when 3 nacks have
  20 // been received for a packet.  Also implements TCP's early retransmit(RFC5827).
  21 class NET_EXPORT_PRIVATE TCPLossAlgorithm : public LossDetectionInterface {
  22  public:
  23   TCPLossAlgorithm();
  24   ~TCPLossAlgorithm() override {}
  25
  26   LossDetectionType GetLossDetectionType() const override;
  27
  28   // Uses nack counts to decide when packets are lost.
  29   SequenceNumberSet DetectLostPackets(
  30       const QuicUnackedPacketMap& unacked_packets,
  31       const QuicTime& time,
  32       QuicPacketSequenceNumber largest_observed,
  33       const RttStats& rtt_stats) override;
  34
  35   // Returns a non-zero value when the early retransmit timer is active.
  36   QuicTime GetLossTimeout() const override;
  37
  38  private:
  39   QuicTime loss_detection_timeout_;
  40
  41   DISALLOW_COPY_AND_ASSIGN(TCPLossAlgorithm);
  42 };
  43
  44 }  // namespace net
  45
  46 #endif  // NET_QUIC_CONGESTION_CONTROL_TCP_LOSS_ALGORITHM_H_