tcpapp.h

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// Copyright (c) Xerox Corporation 1998. All rights reserved.
//
// License is granted to copy, to use, and to make and to use derivative
// works for research and evaluation purposes, provided that Xerox is
// acknowledged in all documentation pertaining to any such copy or
// derivative work. Xerox grants no other licenses expressed or
// implied. The Xerox trade name should not be used in any advertising
// without its written permission. 
//
// XEROX CORPORATION MAKES NO REPRESENTATIONS CONCERNING EITHER THE
// MERCHANTABILITY OF THIS SOFTWARE OR THE SUITABILITY OF THIS SOFTWARE
// FOR ANY PARTICULAR PURPOSE.  The software is provided "as is" without
// express or implied warranty of any kind.
//
// These notices must be retained in any copies of any part of this
// software. 
//
// $Header: /nfs/jade/vint/CVSROOT/ns-2/webcache/tcpapp.h,v 1.14 1999/08/24 04:16:29 haoboy Exp $
//
// TcpApp - Transmitting real application data via TCP
//
// XXX Model a TCP connection as a FIFO byte stream. It shouldn't be used 
// if this assumption is violated.

#ifndef ns_tcpapp_h
#define ns_tcpapp_h

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

class CBuf { 
public:
        CBuf(AppData *c, int nbytes);
        ~CBuf() {
                if (data_ != NULL)
                        delete data_;
        }
        AppData* data() { return data_; }
        int size() { return size_; }
        int bytes() { return nbytes_; }

#ifdef TCPAPP_DEBUG     
        // debug only
        double& time() { return time_; }
#endif

protected:
        friend class CBufList;
        AppData *data_;
        int size_;
        int nbytes_;    // Total length of this transmission
        CBuf *next_;

#ifdef TCPAPP_DEBUG
        // for debug only 
        double time_; 
#endif
};

// A FIFO queue
class CBufList {
public: 
#ifdef TCPAPP_DEBUG 
        CBufList() : head_(NULL), tail_(NULL), num_(0) {}
#else
        CBufList() : head_(NULL), tail_(NULL) {}
#endif
        ~CBufList();

        void insert(CBuf *cbuf);
        CBuf* detach();

protected:
        CBuf *head_;
        CBuf *tail_;
#ifdef TCPAPP_DEBUG
        int num_;
#endif
};


class TcpApp : public Application {
public:
        TcpApp(Agent *tcp);
        ~TcpApp();

        virtual void recv(int nbytes);
        virtual void send(int nbytes, AppData *data);

        void connect(TcpApp *dst) { dst_ = dst; }

        virtual void process_data(int size, AppData* data);
        virtual AppData* get_data(int&, AppData*) {
                // Not supported
                abort();
                return NULL;
        }

        // Do nothing when a connection is terminated
        virtual void resume();

protected:
        virtual int command(int argc, const char*const* argv);
        CBuf* rcvr_retrieve_data() { return cbuf_.detach(); }

        // We don't have start/stop
        virtual void start() { abort(); } 
        virtual void stop() { abort(); }

        TcpApp *dst_;
        CBufList cbuf_;
        CBuf *curdata_;
        int curbytes_;
};

#endif // ns_tcpapp_h

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