// Copyright 2014 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_CONGESTION_CONTROL_TIME_LOSS_ALGORITHM_H_
#define NET_QUIC_CONGESTION_CONTROL_TIME_LOSS_ALGORITHM_H_
#include <algorithm>
#include <map>
#include "base/basictypes.h"
#include "net/quic/congestion_control/loss_detection_interface.h"
#include "net/quic/quic_protocol.h"
#include "net/quic/quic_time.h"
#include "net/quic/quic_unacked_packet_map.h"
namespace net {
// A loss detection algorithm which avoids spurious losses and retransmissions
// by waiting 1.25 RTTs after a packet was sent instead of nack count.
class NET_EXPORT_PRIVATE TimeLossAlgorithm : public LossDetectionInterface {
public:
TimeLossAlgorithm();
virtual ~TimeLossAlgorithm() {}
virtual LossDetectionType GetLossDetectionType() const OVERRIDE;
// Declares pending packets less than the largest observed lost when it has
// been 1.25 RTT since they were sent. Packets larger than the largest
// observed are retransmitted via TLP.
virtual SequenceNumberSet DetectLostPackets(
const QuicUnackedPacketMap& unacked_packets,
const QuicTime& time,
QuicPacketSequenceNumber largest_observed,
const RttStats& rtt_stats) OVERRIDE;
// Returns the time the next packet will be lost, or zero if there
// are no nacked pending packets outstanding.
// TODO(ianswett): Ideally the RTT variance and the RTT would be used to
// determine the time a packet is considered lost.
// TODO(ianswett): Consider using Max(1.25 * srtt, 1.125 * last_rtt).
virtual QuicTime GetLossTimeout() const OVERRIDE;
private:
QuicTime loss_detection_timeout_;
};
} // namespace net
#endif // NET_QUIC_CONGESTION_CONTROL_TIME_LOSS_ALGORITHM_H_