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/*
* Copyright (c) Xerox Corporation 1998. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* 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.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linking this file statically or dynamically with other modules is making
* a combined work based on this file. Thus, the terms and conditions of
* the GNU General Public License cover the whole combination.
*
* In addition, as a special exception, the copyright holders of this file
* give you permission to combine this file 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
* file 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 file 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.
*
* $Header: /cvsroot/nsnam/ns-2/webcache/inval-agent.h,v 1.12 2005/08/26 05:05:31 tomh Exp $
*
*/
//
// Definition of Agent/Invalidation
//
#ifndef ns_invalagent_h
#define ns_invalagent_h
#include <string.h>
#include <tclcl.h>
#include "config.h"
#include "packet.h"
#include "agent.h"
#include "tcpapp.h"
struct hdr_inval {
int size_;
int& size() { return size_; }
// Header access methods
static int offset_; // required by PacketHeaderManager
inline static int& offset() { return offset_; }
inline static hdr_inval* access(const Packet* p) {
return (hdr_inval*) p->access(offset_);
}
};
// XXX If we have an interface declaration, we could define a common
// interface for the two implementations below. But in C++ the only way
// to define an interface is through abstract base class, and use
// multiple inheritance to get different implementations with the same
// interface.
// Because multiple inheritance prohibits conversion from
// base class pointer to derived class pointer, and TclObject::lookup
// must do such a conversion, we cannot declare a common interface here. :(
class HttpApp;
// Implementation 1: multicast, this is a real agent
class HttpInvalAgent : public Agent {
public:
HttpInvalAgent();
virtual void recv(Packet *, Handler *);
virtual void send(int realsize, AppData* data);
protected:
int inval_hdr_size_;
};
// Implementation 2: unicast, actually an application on top of TCP
class HttpUInvalAgent : public TcpApp {
public:
HttpUInvalAgent(Agent *a) : TcpApp(a) {}
void send(int realsize, AppData* data) {
TcpApp::send(realsize, data);
}
virtual void process_data(int size, AppData* data);
virtual AppData* get_data(int&, AppData*) {
abort();
return NULL;
}
protected:
virtual int command(int argc, const char*const* argv);
};
#endif // ns_invalagent_h
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