Adds dynamic setting of FEC group size based on the connection's current

net/quic/quic_sent_packet_manager.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/quic_sent_packet_manager.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/stl_util.h"
@@ skipping 55 matching lines @@
 QuicSentPacketManager::QuicSentPacketManager(bool is_server,
                                              const QuicClock* clock,
                                              QuicConnectionStats* stats,
                                              CongestionFeedbackType type,
                                              LossDetectionType loss_type)
     : unacked_packets_(),
       is_server_(is_server),
       clock_(clock),
       stats_(stats),
       debug_delegate_(NULL),
+      network_change_visitor_(NULL),
       send_algorithm_(
           SendAlgorithmInterface::Create(clock, &rtt_stats_, type, stats)),
       loss_algorithm_(LossDetectionInterface::Create(loss_type)),
       largest_observed_(0),
       first_rto_transmission_(0),
       consecutive_rto_count_(0),
       consecutive_tlp_count_(0),
       consecutive_crypto_retransmission_count_(0),
       pending_tlp_transmission_(false),
       max_tail_loss_probes_(kDefaultMaxTailLossProbes),
@@ skipping 26 matching lines @@
   }
   // TODO(ianswett): Remove the "HasReceivedLossDetection" branch once
   // the ConnectionOptions code is live everywhere.
   if ((config.HasReceivedLossDetection() &&
        config.ReceivedLossDetection() == kTIME) ||
       (config.HasReceivedConnectionOptions() &&
        ContainsQuicTag(config.ReceivedConnectionOptions(), kTIME))) {
     loss_algorithm_.reset(LossDetectionInterface::Create(kTime));
   }
   send_algorithm_->SetFromConfig(config, is_server_);
+
+  if (network_change_visitor_ != NULL) {
+    network_change_visitor_->OnCongestionWindowChange(GetCongestionWindow());
+  }
 }
 
 // TODO(ianswett): Combine this method with OnPacketSent once packets are always
 // sent in order and the connection tracks RetransmittableFrames for longer.
 void QuicSentPacketManager::OnSerializedPacket(
     const SerializedPacket& serialized_packet) {
   if (serialized_packet.retransmittable_frames) {
     ack_notifier_manager_.OnSerializedPacket(serialized_packet);
   }
 
@@ skipping 68 matching lines @@
     debug_delegate_->OnIncomingAck(received_info,
         ack_receive_time,
         largest_observed_,
         largest_observed_acked,
         GetLeastUnackedSentPacket());
   }
 }
 
 void QuicSentPacketManager::MaybeInvokeCongestionEvent(
     bool rtt_updated, QuicByteCount bytes_in_flight) {
-  if (rtt_updated || !packets_acked_.empty() ||
-      !packets_lost_.empty()) {
-    send_algorithm_->OnCongestionEvent(
-        rtt_updated, bytes_in_flight, packets_acked_, packets_lost_);
-    packets_acked_.clear();
-    packets_lost_.clear();
+  if (!rtt_updated && packets_acked_.empty() && packets_lost_.empty()) {
+    return;
+  }
+  send_algorithm_->OnCongestionEvent(rtt_updated, bytes_in_flight,
+                                     packets_acked_, packets_lost_);
+  packets_acked_.clear();
+  packets_lost_.clear();
+  if (network_change_visitor_ != NULL) {
+    network_change_visitor_->OnCongestionWindowChange(GetCongestionWindow());
   }
 }
 
 void QuicSentPacketManager::HandleAckForSentPackets(
     const ReceivedPacketInfo& received_info) {
   // Go through the packets we have not received an ack for and see if this
   // incoming_ack shows they've been seen by the peer.
   QuicTime::Delta delta_largest_observed =
       received_info.delta_time_largest_observed;
   QuicUnackedPacketMap::const_iterator it = unacked_packets_.begin();
@@ skipping 395 matching lines @@
     }
   }
 
   send_algorithm_->OnRetransmissionTimeout(packets_retransmitted);
   if (packets_retransmitted) {
     if (consecutive_rto_count_ == 0) {
       first_rto_transmission_ = unacked_packets_.largest_sent_packet() + 1;
     }
     ++consecutive_rto_count_;
   }
+
+  if (network_change_visitor_ != NULL) {
+    network_change_visitor_->OnCongestionWindowChange(GetCongestionWindow());
+  }
 }
 
 QuicSentPacketManager::RetransmissionTimeoutMode
     QuicSentPacketManager::GetRetransmissionMode() const {
   DCHECK(unacked_packets_.HasInFlightPackets());
   if (unacked_packets_.HasPendingCryptoPackets()) {
     return HANDSHAKE_MODE;
   }
   if (loss_algorithm_->GetLossTimeout() != QuicTime::Zero()) {
     return LOSS_MODE;
@@ skipping 202 matching lines @@
 
   // Set up a pacing sender with a 5 millisecond alarm granularity.
   using_pacing_ = true;
   send_algorithm_.reset(
       new PacingSender(send_algorithm_.release(),
                        QuicTime::Delta::FromMilliseconds(5),
                        kInitialUnpacedBurst));
 }
 
 }  // namespace net