OLD | NEW |
| (Empty) |
1 // Copyright (c) 2013 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 // A send algorithm that adds pacing on top of an another send algorithm. | |
6 // It uses the underlying sender's pacing rate to schedule packets. | |
7 // It also takes into consideration the expected granularity of the underlying | |
8 // alarm to ensure that alarms are not set too aggressively, and err towards | |
9 // sending packets too early instead of too late. | |
10 | |
11 #ifndef NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_ | |
12 #define NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_ | |
13 | |
14 #include <map> | |
15 | |
16 #include "base/basictypes.h" | |
17 #include "base/memory/scoped_ptr.h" | |
18 #include "net/quic/congestion_control/send_algorithm_interface.h" | |
19 #include "net/quic/crypto/cached_network_parameters.h" | |
20 #include "net/quic/quic_bandwidth.h" | |
21 #include "net/quic/quic_config.h" | |
22 #include "net/quic/quic_protocol.h" | |
23 #include "net/quic/quic_time.h" | |
24 | |
25 namespace net { | |
26 | |
27 class NET_EXPORT_PRIVATE PacingSender : public SendAlgorithmInterface { | |
28 public: | |
29 // Create a PacingSender to wrap the specified sender. |alarm_granularity| | |
30 // indicates to the pacer to send that far into the future, since it should | |
31 // not expect a callback before that time delta. |initial_packet_burst| is | |
32 // the number of packets sent without pacing after quiescence. | |
33 PacingSender(SendAlgorithmInterface* sender, | |
34 QuicTime::Delta alarm_granularity, | |
35 uint32 initial_packet_burst); | |
36 ~PacingSender() override; | |
37 | |
38 // SendAlgorithmInterface methods. | |
39 void SetFromConfig(const QuicConfig& config, | |
40 bool is_server, | |
41 bool using_pacing) override; | |
42 bool ResumeConnectionState( | |
43 const CachedNetworkParameters& cached_network_params) override; | |
44 void SetNumEmulatedConnections(int num_connections) override; | |
45 void OnCongestionEvent(bool rtt_updated, | |
46 QuicByteCount bytes_in_flight, | |
47 const CongestionVector& acked_packets, | |
48 const CongestionVector& lost_packets) override; | |
49 bool OnPacketSent(QuicTime sent_time, | |
50 QuicByteCount bytes_in_flight, | |
51 QuicPacketSequenceNumber sequence_number, | |
52 QuicByteCount bytes, | |
53 HasRetransmittableData is_retransmittable) override; | |
54 void OnRetransmissionTimeout(bool packets_retransmitted) override; | |
55 void RevertRetransmissionTimeout() override; | |
56 QuicTime::Delta TimeUntilSend( | |
57 QuicTime now, | |
58 QuicByteCount bytes_in_flight, | |
59 HasRetransmittableData has_retransmittable_data) const override; | |
60 QuicBandwidth PacingRate() const override; | |
61 QuicBandwidth BandwidthEstimate() const override; | |
62 bool HasReliableBandwidthEstimate() const override; | |
63 QuicTime::Delta RetransmissionDelay() const override; | |
64 QuicByteCount GetCongestionWindow() const override; | |
65 bool InSlowStart() const override; | |
66 bool InRecovery() const override; | |
67 QuicByteCount GetSlowStartThreshold() const override; | |
68 CongestionControlType GetCongestionControlType() const override; | |
69 // End implementation of SendAlgorithmInterface. | |
70 | |
71 private: | |
72 scoped_ptr<SendAlgorithmInterface> sender_; // Underlying sender. | |
73 // The estimated system alarm granularity. | |
74 const QuicTime::Delta alarm_granularity_; | |
75 // Configured size of the burst coming out of quiescence. | |
76 const uint32 initial_packet_burst_; | |
77 // Number of unpaced packets to be sent before packets are delayed. | |
78 uint32 burst_tokens_; | |
79 // Send time of the last packet considered delayed. | |
80 QuicTime last_delayed_packet_sent_time_; | |
81 QuicTime ideal_next_packet_send_time_; // When can the next packet be sent. | |
82 mutable bool was_last_send_delayed_; // True when the last send was delayed. | |
83 | |
84 DISALLOW_COPY_AND_ASSIGN(PacingSender); | |
85 }; | |
86 | |
87 } // namespace net | |
88 | |
89 #endif // NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_ | |
OLD | NEW |