ndn-rtt-estimator.hpp

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
//
// Copyright (c) 2006 Georgia Tech Research Corporation
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as
// published by the Free Software Foundation;
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// Author: Rajib Bhattacharjea<raj.b@gatech.edu>
//

// Georgia Tech Network Simulator - Round Trip Time Estimation Class
// George F. Riley.  Georgia Tech, Spring 2002

// THIS IS A COPY OF rtt-estimator.h from internet module with minor modifications

#ifndef NDN_RTT_ESTIMATOR_H
#define NDN_RTT_ESTIMATOR_H

#include <deque>
#include "ns3/sequence-number.h"
#include "ns3/nstime.h"
#include "ns3/object.h"

namespace ns3 {

namespace ndn {

class RttHistory {
public:
  RttHistory(SequenceNumber32 s, uint32_t c, Time t);
  RttHistory(const RttHistory& h); // Copy constructor
public:
  SequenceNumber32 seq; // First sequence number in packet sent
  uint32_t count;       // Number of bytes sent
  Time time;            // Time this one was sent
  bool retx;            // True if this has been retransmitted
};

typedef std::deque<RttHistory> RttHistory_t;

class RttEstimator : public Object {
public:
  static TypeId
  GetTypeId(void);

  RttEstimator();
  RttEstimator(const RttEstimator&);

  virtual ~RttEstimator();

  virtual TypeId
  GetInstanceTypeId(void) const;

  virtual void
  SentSeq(SequenceNumber32 seq, uint32_t size);

  virtual Time
  AckSeq(SequenceNumber32 ackSeq);

  virtual void
  ClearSent();

  virtual void
  Measurement(Time t) = 0;

  virtual Time
  RetransmitTimeout() = 0;

  virtual Ptr<RttEstimator>
  Copy() const = 0;

  virtual void
  IncreaseMultiplier();

  virtual void
  ResetMultiplier();

  virtual void
  Reset();

  void
  SetMinRto(Time minRto);

  Time
  GetMinRto(void) const;

  void
  SetMaxRto(Time maxRto);

  Time
  GetMaxRto(void) const;

  void
  SetCurrentEstimate(Time estimate);

  Time
  GetCurrentEstimate(void) const;

private:
  SequenceNumber32 m_next; // Next expected sequence to be sent
  uint16_t m_maxMultiplier;
  Time m_initialEstimatedRtt;

protected:
  Time m_currentEstimatedRtt; // Current estimate
  Time m_minRto;              // minimum value of the timeout
  Time m_maxRto;              // maximum value of the timeout
  uint32_t m_nSamples;        // Number of samples
  uint16_t m_multiplier;      // RTO Multiplier
  RttHistory_t m_history;     // List of sent packet
};

} // namespace ndn

} // namespace ns3

#endif /* RTT_ESTIMATOR_H */