/Users/yzchen/ns/ns-allinone-2.33/ns-2.33/common/ns-process.h

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

/*
 * ns-process.h
 * Copyright (C) 1997 by the University of Southern California
 * $Id: ns-process.h,v 1.6 2005/08/25 18:58:02 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.
 *
 */

// ADU and ADU processor
//
// $Header: /cvsroot/nsnam/ns-2/common/ns-process.h,v 1.6 2005/08/25 18:58:02 johnh Exp $

#ifndef ns_process_h
#define ns_process_h

#include <assert.h>
#include <string.h>
#include "config.h"

// Application-level data unit types
enum AppDataType {
        // Illegal type
        ADU_ILLEGAL,

        // Old packet data ADU
        PACKET_DATA,

        // HTTP ADUs
        HTTP_DATA,
        HTTP_INVALIDATION,      // Heartbeat that may contain invalidation
        HTTP_UPDATE,            // Pushed page updates (version 1)
        HTTP_PROFORMA,          // Pro forma sent when a direct request is sent
        HTTP_JOIN,
        HTTP_LEAVE,
        HTTP_PUSH,              // Selectively pushed pages 
        HTTP_NORMAL,            // Normal req/resp packets

        // TcpApp ADU
        TCPAPP_STRING,

        // Multimedia ADU
        MEDIA_DATA,
        MEDIA_REQUEST,

        // pub/sub ADU
        PUBSUB,
        
        //Diffusion ADU
        DIFFUSION_DATA,

        // Last ADU
        ADU_LAST

};

// Interface for generic application-level data unit. It should know its 
// size and how to make itself persistent.
class AppData {
private:
        AppDataType type_;      // ADU type
public:
        AppData(AppDataType type) { type_ = type; }
        AppData(AppData& d) { type_ = d.type_; }
        virtual ~AppData() {}

        AppDataType type() const { return type_; }

        // The following two methods MUST be rewrited for EVERY derived classes
        virtual int size() const { return sizeof(AppData); }
        virtual AppData* copy() = 0;
};

// Models any entity that is capable of process an ADU. 
// The basic functionality of this entity is to (1) process data, 
// (2) pass data to another entity, (3) request data from another entity.
class Process : public TclObject {
public: 
        Process() : target_(0) {}
        inline Process*& target() { return target_; }

        // Process incoming data
        virtual void process_data(int size, AppData* data);

        // Request data from the previous application in the chain
        virtual AppData* get_data(int& size, AppData* req_data = 0);

        // Send data to the next application in the chain
        virtual void send_data(int size, AppData* data = 0) {
                if (target_)
                        target_->process_data(size, data);
        }

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

#endif // ns_process_h