webtraf.h

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/* -*-	Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
//
// Copyright (c) 1999 by the University of Southern California
// All rights reserved.
//
// Permission to use, copy, modify, and distribute this software and its
// documentation in source and binary forms for non-commercial purposes
// and without fee is hereby granted, provided that the above copyright
// notice appear in all copies and that both the copyright notice and
// this permission notice appear in supporting documentation. and that
// any documentation, advertising materials, and other materials related
// to such distribution and use acknowledge that the software was
// developed by the University of Southern California, Information
// Sciences Institute.  The name of the University may not be used to
// endorse or promote products derived from this software without
// specific prior written permission.
//
// THE UNIVERSITY OF SOUTHERN CALIFORNIA makes no representations about
// the suitability of this software for any purpose.  THIS SOFTWARE IS
// PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
// INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// Other copyrights might apply to parts of this software and are so
// noted when applicable.
//
// Incorporating Polly's web traffic module into the PagePool framework
//
// XXX This has nothing to do with the HttpApp classes. Because we are 
// only interested in traffic pattern here, we do not want to be bothered 
// with the burden of transmitting HTTP headers, etc. 
//
// $Header: /nfs/jade/vint/CVSROOT/ns-2/webcache/webtraf.h,v 1.5 2000/04/12 17:09:19 haoboy Exp $

#ifndef ns_webtraf_h
#define ns_webtraf_h

#include "ranvar.h"
#include "random.h"
#include "timer-handler.h"

#include "list.h"
#include "node.h"
#include "tcp.h"
#include "tcp-sink.h"
#include "pagepool.h"

const int WEBTRAF_DEFAULT_OBJ_PER_PAGE = 1;

class WebTrafPool;

class WebTrafSession : public TimerHandler {
public: 
	WebTrafSession(WebTrafPool *mgr, Node *src, int np, int id) : 
		rvInterPage_(NULL), rvPageSize_(NULL),
		rvInterObj_(NULL), rvObjSize_(NULL), 
		mgr_(mgr), src_(src), nPage_(np), curPage_(0), donePage_(0),
		id_(id) {}
	virtual ~WebTrafSession();

	// Queried by individual pages/objects
	inline RandomVariable*& interPage() { return rvInterPage_; }
	inline RandomVariable*& pageSize() { return rvPageSize_; }
	inline RandomVariable*& interObj() { return rvInterObj_; }
	inline RandomVariable*& objSize() { return rvObjSize_; }

	void donePage(void* ClntData);
	void launchReq(void* ClntData, int obj, int size);
	inline int id() const { return id_; }

	static int LASTPAGE_;

private:
	virtual void expire(Event *e = 0);
	virtual void handle(Event *e);

	RandomVariable *rvInterPage_, *rvPageSize_, *rvInterObj_, *rvObjSize_;
	WebTrafPool* mgr_;
	Node* src_;		// One source/server per session
	int nPage_, curPage_, donePage_;
	int id_;
};

class WebTrafPool : public PagePool {
public: 
	WebTrafPool(); 
	virtual ~WebTrafPool(); 

	inline Node* picksrc() {
		int n = int(floor(Random::uniform(0, nClient_)));
		assert((n >= 0) && (n < nClient_));
		return client_[n];
	}
	inline Node* pickdst() {
		int n = int(floor(Random::uniform(0, nSrc_)));
		assert((n >= 0) && (n < nSrc_));
		return server_[n];
	}
	inline void doneSession(int idx) { 
		assert((idx>=0) && (idx<nSession_) && (session_[idx]!=NULL));
#if 0
		fprintf(stderr, "deleted session %d", idx);
#endif
		delete session_[idx];
		session_[idx] = NULL; 
	}
	TcpAgent* picktcp();
	TcpSink* picksink();
	inline int nTcp() { return nTcp_; }
	inline int nSink() { return nSink_; }

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

	// Session management: fixed number of sessions, fixed number
	// of pages per session
	int nSession_;
	WebTrafSession** session_; 

	int nSrc_;
	Node** server_;		/* Web servers */
	int nClient_;
	Node** client_; 	/* Browsers */

	// TCP agent pool management
	struct AgentListElem {
		AgentListElem(Agent* a) : agt_(a) {
			link.le_next = NULL;
			link.le_prev = NULL;
		}
		Agent* agt_;
		LIST_ENTRY(AgentListElem) link;
	};
	LIST_HEAD(AgentList, AgentListElem);
	inline void insertAgent(AgentList* l, Agent *a) {
		AgentListElem *e = new AgentListElem(a);
		LIST_INSERT_HEAD(l, e, link);
	}
	inline Agent* detachHead(AgentList* l) {
		AgentListElem *e = l->lh_first;
		if (e == NULL)
			return NULL;
		Agent *a = e->agt_;
		LIST_REMOVE(e, link);
		delete e;
		return a;
	}
	int nTcp_, nSink_;
	AgentList tcpPool_;	/* TCP agent pool */
	AgentList sinkPool_;	/* TCP sink pool */

	// Helper methods
	inline int lookup_rv(RandomVariable*& rv, const char* name) {
		if (rv != NULL)
			Tcl::instance().evalf("delete %s", rv->name());
		rv = (RandomVariable*)lookup_obj(name);
		return rv ? (TCL_OK) : (TCL_ERROR);
	}
};


#endif // ns_webtraf_h