net/quic/quic_ack_notifier_manager.h

   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 #ifndef NET_QUIC_QUIC_ACK_NOTIFIER_MANAGER_H_
   6 #define NET_QUIC_QUIC_ACK_NOTIFIER_MANAGER_H_
   7
   8 #include <map>
   9
  10 #include "base/containers/hash_tables.h"
  11 #include "net/quic/quic_protocol.h"
  12
  13 #if defined(COMPILER_GCC)
  14 namespace BASE_HASH_NAMESPACE {
  15 template<>
  16 struct hash<net::QuicAckNotifier*> {
  17   std::size_t operator()(const net::QuicAckNotifier* ptr) const {
  18     return hash<size_t>()(reinterpret_cast<size_t>(ptr));
  19   }
  20 };
  21 }
  22 #endif
  23
  24 namespace net {
  25
  26 class QuicAckNotifier;
  27
  28 // The AckNotifierManager is used by the QuicSentPacketManager to keep track of
  29 // all the AckNotifiers currently active. It owns the AckNotifiers which it gets
  30 // from the serialized packets passed into OnSerializedPacket. It maintains both
  31 // a set of AckNotifiers and a map from sequence number to AckNotifier the sake
  32 // of efficiency - we can quickly check the map to see if any AckNotifiers are
  33 // interested in a given sequence number.
  34
  35 class NET_EXPORT_PRIVATE AckNotifierManager {
  36  public:
  37   AckNotifierManager();
  38   virtual ~AckNotifierManager();
  39
  40   // Called when the connection receives a new AckFrame.  If |sequence_number|
  41   // exists in ack_notifier_map_ then the corresponding AckNotifiers will have
  42   // their OnAck method called.
  43   void OnPacketAcked(QuicPacketSequenceNumber sequence_number);
  44
  45   // If a packet has been retransmitted with a new sequence number, then this
  46   // will be called. It updates the mapping in ack_notifier_map_, and also
  47   // updates the internal set of sequence numbers in each matching AckNotifier.
  48   void UpdateSequenceNumber(QuicPacketSequenceNumber old_sequence_number,
  49                             QuicPacketSequenceNumber new_sequence_number);
  50
  51   // This is called after a packet has been serialized, is ready to be sent, and
  52   // contains retransmittable frames (which may have associated AckNotifiers).
  53   // If any of the retransmittable frames included in |serialized_packet| have
  54   // AckNotifiers registered, then add them to our internal map and additionally
  55   // inform the AckNotifier of the sequence number which it should track.
  56   void OnSerializedPacket(const SerializedPacket& serialized_packet);
  57
  58  private:
  59   typedef base::hash_set<QuicAckNotifier*> AckNotifierSet;
  60   typedef std::map<QuicPacketSequenceNumber, AckNotifierSet> AckNotifierMap;
  61
  62   // On every ACK frame received by the connection, all the ack_notifiers_ will
  63   // be told which sequeunce numbers were ACKed.
  64   // Once a given QuicAckNotifier has seen all the sequence numbers it is
  65   // interested in, it will be deleted, and removed from this set.
  66   // Owns the AckNotifiers in this set.
  67   AckNotifierSet ack_notifiers_;
  68
  69   // Maps from sequence number to the AckNotifiers which are registered
  70   // for that sequence number. On receipt of an ACK for a given sequence
  71   // number, call OnAck for all mapped AckNotifiers.
  72   // Does not own the AckNotifiers.
  73   AckNotifierMap ack_notifier_map_;
  74 };
  75
  76 }  // namespace net
  77
  78 #endif  // NET_QUIC_QUIC_ACK_NOTIFIER_MANAGER_H_