/Users/yzchen/ns/ns-allinone-2.33/ns-2.33/rap/rap.h

/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */

/*
 * rap.h
 * Copyright (C) 1997 by the University of Southern California
 * $Id: rap.h,v 1.6 2005/08/25 18:58:11 johnh Exp $
 *
 * 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.
 *
 *
 * The copyright of this module includes the following
 * linking-with-specific-other-licenses addition:
 *
 * In addition, as a special exception, the copyright holders of
 * this module give you permission to combine (via static or
 * dynamic linking) this module with free software programs or
 * libraries that are released under the GNU LGPL and with code
 * included in the standard release of ns-2 under the Apache 2.0
 * license or under otherwise-compatible licenses with advertising
 * requirements (or modified versions of such code, with unchanged
 * license).  You may copy and distribute such a system following the
 * terms of the GNU GPL for this module and the licenses of the
 * other code concerned, provided that you include the source code of
 * that other code when and as the GNU GPL requires distribution of
 * source code.
 *
 * Note that people who make modified versions of this module
 * are not obligated to grant this special exception for their
 * modified versions; it is their choice whether to do so.  The GNU
 * General Public License gives permission to release a modified
 * version without this exception; this exception also makes it
 * possible to release a modified version which carries forward this
 * exception.
 *
 */

//
// rap.h 
//      Header File for the 'RAP Source' Agent Class
//
// Author: 
//   Mohit Talwar (mohit@catarina.usc.edu)
//
// $Header: /cvsroot/nsnam/ns-2/rap/rap.h,v 1.6 2005/08/25 18:58:11 johnh Exp $

#ifndef RAP_H
#define RAP_H

#include "ns-process.h"
#include "app.h"
#include "utilities.h"

// RapTimeoutType
//      Possible timeout events

enum RapTimeoutType 
{
        RAP_IPG_TIMEOUT,                // IPG timer fires
        RAP_RTT_TIMEOUT         // RTT timer fires
};

// RapLossType
//      Possible loss types

enum RapLossType 
{
        RAP_TIMER_BASED,                // TIMER based loss detection
        RAP_ACK_BASED                   // ACK based loss detection
};

// RapPacketStatus 
//      Possible packet types in the transmission history

enum RapPacketStatusType
{
        RAP_SENT,                       // Packet has been sent
        RAP_PURGED,                     // Packet detected lost or received
        RAP_INACTIVE                    // Cluster loss ignored
};

class TransHistoryEntry
{
public:
        TransHistoryEntry(int seq, RapPacketStatusType stat = RAP_SENT) {
                seqno = seq;
                status = stat;
                departureTime = Scheduler::instance().clock();
        };

        int seqno;
        RapPacketStatusType status;
        double departureTime;
};

// RAP packet header flags
const int RH_DATA = 0x01;
const int RH_ACK  = 0x02;

struct hdr_rap 
{
        int seqno_;             // Seq num of packet being sent/acked
        int size_;              // Size of user data inside this packet
        int rap_flags_;         // Flags to separate data/ack packets
        
        int lastRecv;           // Last hole at the RAP sink...
        int lastMiss;
        int prevRecv;

        static int offset_;     // offset for this header
        inline static int& offset() { return offset_; }
        inline static hdr_rap* access(const Packet* p) {
                return (hdr_rap*) p->access(offset_);
        }

        int& seqno() { return seqno_; }
        int& size() { return size_; }
        int& flags() { return rap_flags_; }
};

class RapAgent;

class IpgTimer : public TimerHandler
{
public:
        IpgTimer(RapAgent *a) : TimerHandler() { a_ = a; }

protected:
        virtual void expire(Event *e);
        RapAgent *a_;
};

class RttTimer : public TimerHandler
{
public:
        RttTimer(RapAgent *a) : TimerHandler() { a_ = a; }

protected:
        virtual void expire(Event *e);
        RapAgent *a_;
};

// Rap flags
const int RF_ANYACK = 0x01;     // Received first ack
const int RF_STOP   = 0x02;     // This agent has stopped
const int RF_COUNTPKT = 0x04;    // This agent will send up to certain # of pkts

class RapAgent : public Agent   // RAP source
{
public:
        RapAgent();
        ~RapAgent();

        void recv(Packet*, Handler*);
        void timeout(int type);

        int GetSeqno() { return seqno_; }
        double GetTimeout() { return timeout_; }
        int GetDebugFlag() { return debugEnable_; }
        FILE *GetLogfile() { return logfile_; }

        void IncrementLossCount() { sessionLossCount_++; }

        void start();
        void stop();
        void listen();
        void advanceby(int delta);
        void finish();

        // Data member access methods
        double srtt() { return srtt_; }
        double ipg() { return ipg_; }

        int anyack() { return flags_ & RF_ANYACK; }
        int is_stopped() { return flags_ & RF_STOP; }
        int counting_pkt() { return flags_ & RF_COUNTPKT; }
        void FixIpg(double fipg) { fixIpg_ = fipg; }

protected:
        virtual int command(int argc, const char*const* argv);

        void IpgTimeout();              // ipgTimer_ handler
        void RttTimeout();              // rttTimer_ handler

        void IncreaseIpg() { 
                fixIpg_ = 0; 
                ipg_ /= beta_; 
        }
        void DecreaseIpg() { 
                if (fixIpg_ != 0) 
                        ipg_ = fixIpg_;
                else 
                        ipg_ *= srtt_ / (alpha_ * ipg_ + srtt_);
        }
  
        // Adjust RTT estimate based on sample
        void UpdateTimeValues(double sampleRtt); 

        // Detect TIMER_BASED or ACK_BASED losses
        int LossDetection(RapLossType type, hdr_rap *ackHeader = NULL);
        // Increase ipg_ and mark history INACTIVE
        void LossHandler();             

        // Send a DATA packet
        void SendPacket(int nbytes, AppData *data = 0); 
        // Process an ACK
        void RecvAck(hdr_rap *ackHeader); 

        IpgTimer ipgTimer_;             // Send event
        RttTimer rttTimer_;             // IPG decrease event

        List transmissionHistory_;      // Of packets sent out
  
        TracedInt seqno_;               // Current sequence number
        TracedInt sessionLossCount_;    // ~ Packets lost in RAP session
        TracedInt curseq_;              // max # of pkts sent

        TracedDouble ipg_;              // Inter packet gap
        double beta_;                   // Decrease factor
        double alpha_;                  // Increase factor 

        TracedDouble srtt_;             // Smoothened round trip time
        double variance_;               // Variance in rtt samples
        double delta_;                  // Jacobson/Karl 's constants...
        double mu_;
        double phi_;

        double overhead_;               // Max random delay added to IPG

        int useFineGrain_;              // Use fine grain rate adaptation?
        double frtt_;                   // Fine grain feedback signals
        double xrtt_;
        double kxrtt_;
        double kfrtt_;

        TracedDouble timeout_;  // Timeout estimate

        double startTime_, stopTime_;   // Of this agent's life

        int debugEnable_;
        FILE *logfile_;

        // Data and methods as required by RAP receiver
        int lastRecv_;          // Last hole at the RAP sink...
        int lastMiss_;
        int prevRecv_;
        void UpdateLastHole(int seqNum);
        void SendAck(int seqNum);

        int rap_base_hdr_size_;

        // Data packet counter: the number of data packets that we've sent 
        // in a RTT. If we have not sent much we should not increase 
        // rate because we don't have enough packets to probe for losses
        int dctr_;
        // The percentage threshold for increasing rate.
        int dpthresh_; 

        // Misc flags
        int flags_;
        double fixIpg_;
};

#endif // RAP_H