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| 1 // Copyright 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 // Manages the packet entropy calculation for both sent and received packets | |
| 6 // for a connection. | |
| 7 | |
| 8 #ifndef NET_QUIC_QUIC_RECEIVED_PACKET_MANAGER_H_ | |
| 9 #define NET_QUIC_QUIC_RECEIVED_PACKET_MANAGER_H_ | |
| 10 | |
| 11 #include <deque> | |
| 12 | |
| 13 #include "net/quic/quic_config.h" | |
| 14 #include "net/quic/quic_framer.h" | |
| 15 #include "net/quic/quic_protocol.h" | |
| 16 | |
| 17 namespace net { | |
| 18 | |
| 19 namespace test { | |
| 20 class EntropyTrackerPeer; | |
| 21 class QuicConnectionPeer; | |
| 22 class QuicReceivedPacketManagerPeer; | |
| 23 } // namespace test | |
| 24 | |
| 25 struct QuicConnectionStats; | |
| 26 | |
| 27 // Records all received packets by a connection and tracks their entropy. | |
| 28 // Also calculates the correct entropy for the framer when it truncates an ack | |
| 29 // frame being serialized. | |
| 30 class NET_EXPORT_PRIVATE QuicReceivedPacketManager : | |
| 31 public QuicReceivedEntropyHashCalculatorInterface { | |
| 32 public: | |
| 33 class NET_EXPORT_PRIVATE EntropyTracker { | |
| 34 public: | |
| 35 EntropyTracker(); | |
| 36 ~EntropyTracker(); | |
| 37 | |
| 38 // Compute the XOR of the entropy of all received packets up to | |
| 39 // and including sequence_number. | |
| 40 // Requires that either: | |
| 41 // sequence_number == largest_observed_ | |
| 42 // or: | |
| 43 // sequence_number > first_gap_ && | |
| 44 // sequence_number < largest_observed_ && | |
| 45 // sequence_number in packets_entropy_ | |
| 46 QuicPacketEntropyHash EntropyHash( | |
| 47 QuicPacketSequenceNumber sequence_number) const; | |
| 48 | |
| 49 // Record the received entropy hash against |sequence_number|. | |
| 50 // Performs garbage collection to advance first_gap_ if | |
| 51 // sequence_number == first_gap_. | |
| 52 void RecordPacketEntropyHash(QuicPacketSequenceNumber sequence_number, | |
| 53 QuicPacketEntropyHash entropy_hash); | |
| 54 | |
| 55 // Sets the entropy hash up to but not including a sequence number based | |
| 56 // on the hash provided by a StopWaiting frame. Clears older packet | |
| 57 // entropy entries and performs garbage collection up to the first gap. | |
| 58 void SetCumulativeEntropyUpTo(QuicPacketSequenceNumber sequence_number, | |
| 59 QuicPacketEntropyHash entropy_hash); | |
| 60 | |
| 61 size_t size() const { return packets_entropy_.size(); } | |
| 62 | |
| 63 private: | |
| 64 friend class test::EntropyTrackerPeer; | |
| 65 | |
| 66 // A deque indexed by sequence number storing the packet's hash and whether | |
| 67 // a hash was recorded for that sequence number. | |
| 68 typedef std::deque<std::pair<QuicPacketEntropyHash, bool> > | |
| 69 ReceivedEntropyHashes; | |
| 70 | |
| 71 // Recomputes first_gap_ and removes packets_entropy_ entries that are no | |
| 72 // longer needed to compute EntropyHash. | |
| 73 void AdvanceFirstGapAndGarbageCollectEntropyMap(); | |
| 74 | |
| 75 // Map of received sequence numbers to their corresponding entropy. | |
| 76 // Stores an entry for every received packet whose sequence_number is larger | |
| 77 // than first_gap_. Packets without the entropy bit set have an entropy | |
| 78 // value of 0. | |
| 79 ReceivedEntropyHashes packets_entropy_; | |
| 80 | |
| 81 // Cumulative hash of entropy of all received packets. | |
| 82 QuicPacketEntropyHash packets_entropy_hash_; | |
| 83 | |
| 84 // Sequence number of the first packet that we do not know the entropy of. | |
| 85 // If there are no gaps in the received packet sequence, | |
| 86 // packets_entropy_ will be empty and first_gap_ will be equal to | |
| 87 // 'largest_observed_ + 1' since that's the first packet for which | |
| 88 // entropy is unknown. If there are gaps, packets_entropy_ will | |
| 89 // contain entries for all received packets with sequence_number > | |
| 90 // first_gap_. | |
| 91 QuicPacketSequenceNumber first_gap_; | |
| 92 | |
| 93 // Sequence number of the largest observed packet. | |
| 94 QuicPacketSequenceNumber largest_observed_; | |
| 95 | |
| 96 DISALLOW_COPY_AND_ASSIGN(EntropyTracker); | |
| 97 }; | |
| 98 | |
| 99 explicit QuicReceivedPacketManager(QuicConnectionStats* stats); | |
| 100 ~QuicReceivedPacketManager() override; | |
| 101 | |
| 102 // Updates the internal state concerning which packets have been received. | |
| 103 // bytes: the packet size in bytes including Quic Headers. | |
| 104 // header: the packet header. | |
| 105 // timestamp: the arrival time of the packet. | |
| 106 void RecordPacketReceived(QuicByteCount bytes, | |
| 107 const QuicPacketHeader& header, | |
| 108 QuicTime receipt_time); | |
| 109 | |
| 110 void RecordPacketRevived(QuicPacketSequenceNumber sequence_number); | |
| 111 | |
| 112 // Checks whether |sequence_number| is missing and less than largest observed. | |
| 113 bool IsMissing(QuicPacketSequenceNumber sequence_number); | |
| 114 | |
| 115 // Checks if we're still waiting for the packet with |sequence_number|. | |
| 116 bool IsAwaitingPacket(QuicPacketSequenceNumber sequence_number); | |
| 117 | |
| 118 // Update the |ack_frame| for an outgoing ack. | |
| 119 void UpdateReceivedPacketInfo(QuicAckFrame* ack_frame, | |
| 120 QuicTime approximate_now); | |
| 121 | |
| 122 // QuicReceivedEntropyHashCalculatorInterface | |
| 123 // Called by QuicFramer, when the outgoing ack gets truncated, to recalculate | |
| 124 // the received entropy hash for the truncated ack frame. | |
| 125 QuicPacketEntropyHash EntropyHash( | |
| 126 QuicPacketSequenceNumber sequence_number) const override; | |
| 127 | |
| 128 // Updates internal state based on |stop_waiting|. | |
| 129 void UpdatePacketInformationSentByPeer( | |
| 130 const QuicStopWaitingFrame& stop_waiting); | |
| 131 | |
| 132 // Returns true when there are new missing packets to be reported within 3 | |
| 133 // packets of the largest observed. | |
| 134 bool HasNewMissingPackets() const; | |
| 135 | |
| 136 // Returns the number of packets being tracked in the EntropyTracker. | |
| 137 size_t NumTrackedPackets() const; | |
| 138 | |
| 139 QuicPacketSequenceNumber peer_least_packet_awaiting_ack() { | |
| 140 return peer_least_packet_awaiting_ack_; | |
| 141 } | |
| 142 | |
| 143 private: | |
| 144 friend class test::QuicConnectionPeer; | |
| 145 friend class test::QuicReceivedPacketManagerPeer; | |
| 146 | |
| 147 // Deletes all missing packets before least unacked. The connection won't | |
| 148 // process any packets with sequence number before |least_unacked| that it | |
| 149 // received after this call. Returns true if there were missing packets before | |
| 150 // |least_unacked| unacked, false otherwise. | |
| 151 bool DontWaitForPacketsBefore(QuicPacketSequenceNumber least_unacked); | |
| 152 | |
| 153 // Tracks entropy hashes of received packets. | |
| 154 EntropyTracker entropy_tracker_; | |
| 155 | |
| 156 // Least sequence number of the the packet sent by the peer for which it | |
| 157 // hasn't received an ack. | |
| 158 QuicPacketSequenceNumber peer_least_packet_awaiting_ack_; | |
| 159 | |
| 160 // Received packet information used to produce acks. | |
| 161 QuicAckFrame ack_frame_; | |
| 162 | |
| 163 // The time we received the largest_observed sequence number, or zero if | |
| 164 // no sequence numbers have been received since UpdateReceivedPacketInfo. | |
| 165 // Needed for calculating delta_time_largest_observed. | |
| 166 QuicTime time_largest_observed_; | |
| 167 | |
| 168 QuicConnectionStats* stats_; | |
| 169 | |
| 170 PacketTimeList received_packet_times_; | |
| 171 | |
| 172 DISALLOW_COPY_AND_ASSIGN(QuicReceivedPacketManager); | |
| 173 }; | |
| 174 | |
| 175 } // namespace net | |
| 176 | |
| 177 #endif // NET_QUIC_QUIC_RECEIVED_PACKET_MANAGER_H_ | |
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Chromium Code Reviews
Issue 992733002:
Remove //net (except for Android test stuff) and sdch (Closed)
Base URL: git@github.com:domokit/mojo.git@master