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)
14namespace BASE_HASH_NAMESPACE {
15template<>
16struct 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
24namespace net {
25
26class 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.
34class NET_EXPORT_PRIVATE AckNotifierManager {
35 public:
36  AckNotifierManager();
37  virtual ~AckNotifierManager();
38
39  // Called when the connection receives a new AckFrame.  If |sequence_number|
40  // exists in ack_notifier_map_ then the corresponding AckNotifiers will have
41  // their OnAck method called.
42  void OnPacketAcked(QuicPacketSequenceNumber sequence_number,
43                     QuicTime::Delta delta_largest_observed);
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  DISALLOW_COPY_AND_ASSIGN(AckNotifierManager);
76};
77
78}  // namespace net
79
80#endif  // NET_QUIC_QUIC_ACK_NOTIFIER_MANAGER_H_
81