blob: 6bf6aa8cba95e3b2040ea4dd677190c7cdde1ec3 [file] [log] [blame]
/* -*- 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 {
/**
* \ingroup tcp
*
* \brief Helper class to store RTT measurements
*/
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;
/**
* \ingroup tcp
*
* \brief Base class for all RTT Estimators
*/
class RttEstimator : public Object {
public:
static TypeId GetTypeId (void);
RttEstimator();
RttEstimator (const RttEstimator&);
virtual ~RttEstimator();
/**
* \brief Note that a particular sequence has been sent
* \param seq the packet sequence number.
* \param size the packet size.
*/
virtual void SentSeq (SequenceNumber32 seq, uint32_t size);
/**
* \brief Note that a particular ack sequence has been received
* \param ackSeq the ack sequence number.
* \return The measured RTT for this ack.
*/
virtual Time AckSeq (SequenceNumber32 ackSeq);
/**
* \brief Clear all history entries
*/
virtual void ClearSent ();
/**
* \brief Add a new measurement to the estimator. Pure virtual function.
* \param t the new RTT measure.
*/
virtual void Measurement (Time t) = 0;
/**
* \brief Returns the estimated RTO. Pure virtual function.
* \return the estimated RTO.
*/
virtual Time RetransmitTimeout () = 0;
virtual Ptr<RttEstimator> Copy () const = 0;
/**
* \brief Increase the estimation multiplier up to MaxMultiplier.
*/
virtual void IncreaseMultiplier ();
/**
* \brief Resets the estimation multiplier to 1.
*/
virtual void ResetMultiplier ();
/**
* \brief Resets the estimation to its initial state.
*/
virtual void Reset ();
/**
* \brief Sets the Minimum RTO.
* \param minRto The minimum RTO returned by the estimator.
*/
void SetMinRto (Time minRto);
/**
* \brief Get the Minimum RTO.
* \return The minimum RTO returned by the estimator.
*/
Time GetMinRto (void) const;
/**
* \brief Sets the Maximum RTO.
* \param minRto The maximum RTO returned by the estimator.
*/
void SetMaxRto (Time maxRto);
/**
* \brief Get the Maximum RTO.
* \return The maximum RTO returned by the estimator.
*/
Time GetMaxRto (void) const;
/**
* \brief Sets the current RTT estimate (forcefully).
* \param estimate The current RTT estimate.
*/
void SetCurrentEstimate (Time estimate);
/**
* \brief gets the current RTT estimate.
* \return The current RTT 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 */