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

net/quic/quic_sent_packet_manager.h

 // 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.
 
 #ifndef NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_
 #define NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_
 
 #include <deque>
 #include <list>
 #include <map>
@@ skipping 54 matching lines @@
         QuicTime time) {}
 
     virtual void OnIncomingAck(
         const ReceivedPacketInfo& received_info,
         QuicTime ack_receive_time,
         QuicPacketSequenceNumber largest_observed,
         bool largest_observed_acked,
         QuicPacketSequenceNumber least_unacked_sent_packet) {}
   };
 
+  // Interface which gets callbacks from the QuicSentPacketManager when
+  // network-related state changes. Implementations must not mutate the
+  // state of the packet manager as a result of these callbacks.
+  class NetworkChangeVisitor {
+   public:
+    virtual ~NetworkChangeVisitor() {}
+
+    // Called when congestion window may have changed.
+    virtual void OnCongestionWindowChange(QuicByteCount congestion_window) = 0;
+    // TODO(jri): Add OnRttStatsChange() to this class as well.
+  };
+
   // Struct to store the pending retransmission information.
   struct PendingRetransmission {
     PendingRetransmission(QuicPacketSequenceNumber sequence_number,
                           TransmissionType transmission_type,
                           const RetransmittableFrames& retransmittable_frames,
                           QuicSequenceNumberLength sequence_number_length)
             : sequence_number(sequence_number),
               transmission_type(transmission_type),
               retransmittable_frames(retransmittable_frames),
               sequence_number_length(sequence_number_length) {
@@ skipping 118 matching lines @@
   bool using_pacing() const { return using_pacing_; }
 
   void set_debug_delegate(DebugDelegate* debug_delegate) {
     debug_delegate_ = debug_delegate;
   }
 
   QuicPacketSequenceNumber largest_observed() const {
     return largest_observed_;
   }
 
+  void set_network_change_visitor(NetworkChangeVisitor* visitor) {
+    DCHECK(!network_change_visitor_);
+    DCHECK(visitor);
+    network_change_visitor_ = visitor;
+  }
+
  private:
   friend class test::QuicConnectionPeer;
   friend class test::QuicSentPacketManagerPeer;
 
   // The retransmission timer is a single timer which switches modes depending
   // upon connection state.
   enum RetransmissionTimeoutMode {
     // A conventional TCP style RTO.
     RTO_MODE,
     // A tail loss probe.  By default, QUIC sends up to two before RTOing.
@@ skipping 86 matching lines @@
   bool is_server_;
 
   // An AckNotifier can register to be informed when ACKs have been received for
   // all packets that a given block of data was sent in. The AckNotifierManager
   // maintains the currently active notifiers.
   AckNotifierManager ack_notifier_manager_;
 
   const QuicClock* clock_;
   QuicConnectionStats* stats_;
   DebugDelegate* debug_delegate_;
+  NetworkChangeVisitor* network_change_visitor_;
   RttStats rtt_stats_;
   scoped_ptr<SendAlgorithmInterface> send_algorithm_;
   scoped_ptr<LossDetectionInterface> loss_algorithm_;
 
   // The largest sequence number which we have sent and received an ACK for
   // from the peer.
   QuicPacketSequenceNumber largest_observed_;
 
   // Tracks the first RTO packet.  If any packet before that packet gets acked,
   // it indicates the RTO was spurious and should be reversed(F-RTO).
@@ skipping 13 matching lines @@
   // Sets of packets acked and lost as a result of the last congestion event.
   SendAlgorithmInterface::CongestionMap packets_acked_;
   SendAlgorithmInterface::CongestionMap packets_lost_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicSentPacketManager);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_