net/quic/quic_ack_notifier_manager.cc

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