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