Move shared files in net/quic/ into net/quic/core/

net/quic/congestion_control/hybrid_slow_start.h

-// Copyright (c) 2012 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.
-//
-// This class is a helper class to TcpCubicSender.
-// Slow start is the initial startup phase of TCP, it lasts until first packet
-// loss. This class implements hybrid slow start of the TCP cubic send side
-// congestion algorithm. The key feaure of hybrid slow start is that it tries to
-// avoid running into the wall too hard during the slow start phase, which
-// the traditional TCP implementation does.
-// This does not implement ack train detection because it interacts poorly with
-// pacing.
-// http://netsrv.csc.ncsu.edu/export/hybridstart_pfldnet08.pdf
-// http://research.csc.ncsu.edu/netsrv/sites/default/files/hystart_techreport_2008.pdf
-
-#ifndef NET_QUIC_CONGESTION_CONTROL_HYBRID_SLOW_START_H_
-#define NET_QUIC_CONGESTION_CONTROL_HYBRID_SLOW_START_H_
-
-#include <stdint.h>
-
-#include "base/macros.h"
-#include "net/base/net_export.h"
-#include "net/quic/quic_protocol.h"
-#include "net/quic/quic_time.h"
-
-namespace net {
-
-class NET_EXPORT_PRIVATE HybridSlowStart {
- public:
-  HybridSlowStart();
-
-  void OnPacketAcked(QuicPacketNumber acked_packet_number);
-
-  void OnPacketSent(QuicPacketNumber packet_number);
-
-  // ShouldExitSlowStart should be called on every new ack frame, since a new
-  // RTT measurement can be made then.
-  // rtt: the RTT for this ack packet.
-  // min_rtt: is the lowest delay (RTT) we have seen during the session.
-  // congestion_window: the congestion window in packets.
-  bool ShouldExitSlowStart(QuicTime::Delta rtt,
-                           QuicTime::Delta min_rtt,
-                           QuicPacketCount congestion_window);
-
-  // Start a new slow start phase.
-  void Restart();
-
-  // TODO(ianswett): The following methods should be private, but that requires
-  // a follow up CL to update the unit test.
-  // Returns true if this ack the last packet number of our current slow start
-  // round.
-  // Call Reset if this returns true.
-  bool IsEndOfRound(QuicPacketNumber ack) const;
-
-  // Call for the start of each receive round (burst) in the slow start phase.
-  void StartReceiveRound(QuicPacketNumber last_sent);
-
-  // Whether slow start has started.
-  bool started() const { return started_; }
-
- private:
-  // Whether a condition for exiting slow start has been found.
-  enum HystartState {
-    NOT_FOUND,
-    DELAY,  // Too much increase in the round's min_rtt was observed.
-  };
-
-  // Whether the hybrid slow start has been started.
-  bool started_;
-  HystartState hystart_found_;
-  // Last packet number sent which was CWND limited.
-  QuicPacketNumber last_sent_packet_number_;
-
-  // Variables for tracking acks received during a slow start round.
-  QuicPacketNumber end_packet_number_;  // End of the receive round.
-  uint32_t rtt_sample_count_;  // Number of rtt samples in the current round.
-  QuicTime::Delta current_min_rtt_;  // The minimum rtt of current round.
-
-  DISALLOW_COPY_AND_ASSIGN(HybridSlowStart);
-};
-
-}  // namespace net
-
-#endif  // NET_QUIC_CONGESTION_CONTROL_HYBRID_SLOW_START_H_