1 // Copyright (c) 2012 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 // The pure virtual class for send side congestion control algorithm. 6 7 #ifndef NET_QUIC_CONGESTION_CONTROL_SEND_ALGORITHM_INTERFACE_H_ 8 #define NET_QUIC_CONGESTION_CONTROL_SEND_ALGORITHM_INTERFACE_H_ 9 10 #include <algorithm> 11 #include <map> 12 13 #include "base/basictypes.h" 14 #include "net/base/net_export.h" 15 #include "net/quic/quic_bandwidth.h" 16 #include "net/quic/quic_clock.h" 17 #include "net/quic/quic_config.h" 18 #include "net/quic/quic_protocol.h" 19 #include "net/quic/quic_time.h" 20 21 namespace net { 22 23 class NET_EXPORT_PRIVATE SendAlgorithmInterface { 24 public: 25 class SentPacket { 26 public: SentPacket(QuicByteCount bytes,QuicTime timestamp,HasRetransmittableData has_retransmittable_data)27 SentPacket(QuicByteCount bytes, 28 QuicTime timestamp, 29 HasRetransmittableData has_retransmittable_data) 30 : bytes_sent_(bytes), 31 send_timestamp_(timestamp), 32 has_retransmittable_data_(has_retransmittable_data), 33 nack_count_(0) { 34 } bytes_sent()35 QuicByteCount bytes_sent() const { return bytes_sent_; } send_timestamp()36 const QuicTime& send_timestamp() const { return send_timestamp_; } has_retransmittable_data()37 HasRetransmittableData has_retransmittable_data() const { 38 return has_retransmittable_data_; 39 } nack_count()40 size_t nack_count() const { return nack_count_; } 41 Nack(size_t min_nacks)42 void Nack(size_t min_nacks) { 43 nack_count_ = std::max(min_nacks, nack_count_ + 1); 44 } 45 46 private: 47 QuicByteCount bytes_sent_; 48 QuicTime send_timestamp_; 49 HasRetransmittableData has_retransmittable_data_; 50 size_t nack_count_; 51 }; 52 53 typedef std::map<QuicPacketSequenceNumber, SentPacket*> SentPacketsMap; 54 55 static SendAlgorithmInterface* Create(const QuicClock* clock, 56 CongestionFeedbackType type); 57 ~SendAlgorithmInterface()58 virtual ~SendAlgorithmInterface() {} 59 60 virtual void SetFromConfig(const QuicConfig& config, bool is_server) = 0; 61 62 // Sets the maximum size of packets that will be sent. 63 virtual void SetMaxPacketSize(QuicByteCount max_packet_size) = 0; 64 65 // Called when we receive congestion feedback from remote peer. 66 virtual void OnIncomingQuicCongestionFeedbackFrame( 67 const QuicCongestionFeedbackFrame& feedback, 68 QuicTime feedback_receive_time, 69 const SentPacketsMap& sent_packets) = 0; 70 71 // Called for each received ACK, with sequence number from remote peer. 72 virtual void OnPacketAcked(QuicPacketSequenceNumber acked_sequence_number, 73 QuicByteCount acked_bytes, 74 QuicTime::Delta rtt) = 0; 75 76 // Indicates a loss event of one packet. |sequence_number| is the 77 // sequence number of the lost packet. 78 virtual void OnPacketLost(QuicPacketSequenceNumber sequence_number, 79 QuicTime ack_receive_time) = 0; 80 81 // Inform that we sent x bytes to the wire, and if that was a retransmission. 82 // Returns true if the packet should be tracked by the congestion manager, 83 // false otherwise. This is used by implementations such as tcp_cubic_sender 84 // that do not count outgoing ACK packets against the congestion window. 85 // Note: this function must be called for every packet sent to the wire. 86 virtual bool OnPacketSent(QuicTime sent_time, 87 QuicPacketSequenceNumber sequence_number, 88 QuicByteCount bytes, 89 TransmissionType transmission_type, 90 HasRetransmittableData is_retransmittable) = 0; 91 92 // Called when the retransmission timeout fires. 93 virtual void OnRetransmissionTimeout() = 0; 94 95 // Called when a packet is timed out. 96 virtual void OnPacketAbandoned(QuicPacketSequenceNumber sequence_number, 97 QuicByteCount abandoned_bytes) = 0; 98 99 // Calculate the time until we can send the next packet. 100 virtual QuicTime::Delta TimeUntilSend( 101 QuicTime now, 102 TransmissionType transmission_type, 103 HasRetransmittableData has_retransmittable_data, 104 IsHandshake handshake) = 0; 105 106 // What's the current estimated bandwidth in bytes per second. 107 // Returns 0 when it does not have an estimate. 108 virtual QuicBandwidth BandwidthEstimate() const = 0; 109 110 // TODO(satyamshekhar): Monitor MinRtt. 111 virtual QuicTime::Delta SmoothedRtt() const = 0; 112 113 // Get the send algorithm specific retransmission delay, called RTO in TCP, 114 // Note 1: the caller is responsible for sanity checking this value. 115 // Note 2: this will return zero if we don't have enough data for an estimate. 116 virtual QuicTime::Delta RetransmissionDelay() const = 0; 117 118 // Returns the size of the current congestion window in bytes. Note, this is 119 // not the *available* window. Some send algorithms may not use a congestion 120 // window and will return 0. 121 virtual QuicByteCount GetCongestionWindow() const = 0; 122 }; 123 124 } // namespace net 125 126 #endif // NET_QUIC_CONGESTION_CONTROL_SEND_ALGORITHM_INTERFACE_H_ 127