Land Recent QUIC Changes.

net/quic/congestion_control/pacing_sender.h

 // Copyright (c) 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.
 //
 // A send algorithm which adds pacing on top of an another send algorithm.
 // It uses the underlying sender's bandwidth estimate to determine the
 // pacing rate to be used.  It also takes into consideration the expected
 // resolution of the underlying alarm mechanism to ensure that alarms are
 // not set too aggressively, and to smooth out variations.
 
 #ifndef NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_
 #define NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "net/quic/congestion_control/send_algorithm_interface.h"
 #include "net/quic/quic_bandwidth.h"
 #include "net/quic/quic_config.h"
 #include "net/quic/quic_protocol.h"
 #include "net/quic/quic_time.h"
 
 namespace net {
 
 class NET_EXPORT_PRIVATE PacingSender : public SendAlgorithmInterface {
  public:
+  // Create a PacingSender to wrap the specified sender.  |alarm_granularity|
+  // indicates to the pacer to send that far into the future, since it should
+  // not expect a callback before that time delta.  |initial_packet_burst| is
+  // the number of packets sent without pacing after quiescence.
   PacingSender(SendAlgorithmInterface* sender,
-               QuicTime::Delta alarm_granularity);
+               QuicTime::Delta alarm_granularity,
+               uint32 initial_packet_burst);
   virtual ~PacingSender();
 
   // SendAlgorithmInterface methods.
   virtual void SetFromConfig(const QuicConfig& config, bool is_server) OVERRIDE;
   virtual void OnIncomingQuicCongestionFeedbackFrame(
       const QuicCongestionFeedbackFrame& feedback,
       QuicTime feedback_receive_time) OVERRIDE;
   virtual void OnCongestionEvent(bool rtt_updated,
                                  QuicByteCount bytes_in_flight,
                                  const CongestionMap& acked_packets,
                                  const CongestionMap& lost_packets) OVERRIDE;
   virtual bool OnPacketSent(QuicTime sent_time,
                             QuicByteCount bytes_in_flight,
                             QuicPacketSequenceNumber sequence_number,
                             QuicByteCount bytes,
                             HasRetransmittableData is_retransmittable) OVERRIDE;
   virtual void OnRetransmissionTimeout(bool packets_retransmitted) OVERRIDE;
   virtual void RevertRetransmissionTimeout() OVERRIDE;
   virtual QuicTime::Delta TimeUntilSend(
       QuicTime now,
       QuicByteCount bytes_in_flight,
       HasRetransmittableData has_retransmittable_data) const OVERRIDE;
   virtual QuicBandwidth BandwidthEstimate() const OVERRIDE;
+  virtual bool HasReliableBandwidthEstimate() const OVERRIDE;
   virtual QuicTime::Delta RetransmissionDelay() const OVERRIDE;
   virtual QuicByteCount GetCongestionWindow() const OVERRIDE;
 
  private:
   scoped_ptr<SendAlgorithmInterface> sender_;  // Underlying sender.
   QuicTime::Delta alarm_granularity_;
+  uint32 initial_packet_burst_;
+  uint32 burst_tokens_;
   // Send time of the last packet considered delayed.
   QuicTime last_delayed_packet_sent_time_;
   QuicTime next_packet_send_time_;  // When can the next packet be sent.
   mutable bool was_last_send_delayed_;  // True when the last send was delayed.
   bool has_valid_rtt_;  // True if we have at least one RTT update.
 
   DISALLOW_COPY_AND_ASSIGN(PacingSender);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_