quic_ack_notifier_manager.cc revision 4e180b6a0b4720a9b8e9e959a882386f690f08ff 
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#include "net/quic/quic_ack_notifier_manager.h"
6
7#include <stddef.h>
8#include <list>
9#include <map>
10#include <utility>
11#include <vector>
12
13#include "base/stl_util.h"
14#include "net/quic/quic_ack_notifier.h"
15#include "net/quic/quic_protocol.h"
16
17namespace net {
18
19AckNotifierManager::AckNotifierManager() {}
20
21AckNotifierManager::~AckNotifierManager() {
22  STLDeleteElements(&ack_notifiers_);
23}
24
25void AckNotifierManager::OnPacketAcked(
26    QuicPacketSequenceNumber sequence_number) {
27  // Inform all the registered AckNotifiers of the new ACK.
28  AckNotifierMap::iterator map_it = ack_notifier_map_.find(sequence_number);
29  if (map_it == ack_notifier_map_.end()) {
30    // No AckNotifier is interested in this sequence number.
31    return;
32  }
33
34  // One or more AckNotifiers are registered as interested in this sequence
35  // number. Iterate through them and call OnAck on each.
36  for (AckNotifierSet::iterator set_it = map_it->second.begin();
37       set_it != map_it->second.end(); ++set_it) {
38    QuicAckNotifier* ack_notifier = *set_it;
39    ack_notifier->OnAck(sequence_number);
40
41    // If this has resulted in an empty AckNotifer, erase it.
42    if (ack_notifier->IsEmpty()) {
43      delete ack_notifier;
44      ack_notifiers_.erase(ack_notifier);
45    }
46  }
47
48  // Remove the sequence number from the map as we have notified all the
49  // registered AckNotifiers, and we won't see it again.
50  ack_notifier_map_.erase(map_it);
51}
52
53void AckNotifierManager::UpdateSequenceNumber(
54    QuicPacketSequenceNumber old_sequence_number,
55    QuicPacketSequenceNumber new_sequence_number) {
56  AckNotifierMap::iterator map_it = ack_notifier_map_.find(old_sequence_number);
57  if (map_it != ack_notifier_map_.end()) {
58    // We will add an entry to the map for the new sequence number, and move
59    // the
60    // list of AckNotifiers over.
61    AckNotifierSet new_set;
62    for (AckNotifierSet::iterator notifier_it = map_it->second.begin();
63         notifier_it != map_it->second.end(); ++notifier_it) {
64      (*notifier_it)
65          ->UpdateSequenceNumber(old_sequence_number, new_sequence_number);
66      new_set.insert(*notifier_it);
67    }
68    ack_notifier_map_[new_sequence_number] = new_set;
69    ack_notifier_map_.erase(map_it);
70  }
71}
72
73void AckNotifierManager::OnSerializedPacket(
74    const SerializedPacket& serialized_packet) {
75  // Run through all the frames and if any of them are stream frames and have
76  // an AckNotifier registered, then inform the AckNotifier that it should be
77  // interested in this packet's sequence number.
78
79  RetransmittableFrames* frames = serialized_packet.retransmittable_frames;
80
81  // AckNotifiers can only be attached to retransmittable frames.
82  if (!frames) {
83    return;
84  }
85
86  for (QuicFrames::const_iterator it = frames->frames().begin();
87       it != frames->frames().end(); ++it) {
88    if (it->type == STREAM_FRAME && it->stream_frame->notifier != NULL) {
89      // The AckNotifier needs to know it is tracking this packet's sequence
90      // number.
91      it->stream_frame->notifier->AddSequenceNumber(
92          serialized_packet.sequence_number);
93
94      // Add the AckNotifier to our set of AckNotifiers.
95      ack_notifiers_.insert(it->stream_frame->notifier);
96
97      // Update the mapping in the other direction, from sequence
98      // number to AckNotifier.
99      ack_notifier_map_[serialized_packet.sequence_number]
100          .insert(it->stream_frame->notifier);
101    }
102  }
103}
104
105}  // namespace net
106