messagerouter.java

Java Communicating Agents是一个用于开发网络反应式信息agent的框架

/*
 * $Source: /home/data/cvsroot/src/jacomma/platform/engine/MessageRouter.java,v $
 * $Revision: 1.4 $
 * $Date: 2000/10/28 20:09:08 $
 *
 * This file is part of the jacomma framework
 * Copyright (c) 2000 	Dimitrios Vyzovitis
 *			mailto:[e-mail]
 *			
 *
 *			
 *			
 *			
 *
 *	This library is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU Library General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This library 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 Library General Public License for more details.
 *
 *	You should have received a copy of the GNU Library General Public License
 *	along with this library; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, 
 *	Boston, MA  02111-1307  USA
 */

package jacomma.platform.engine;

import java.net.InetAddress;

import java.util.Map;
import java.util.HashMap;
import java.util.Set;
import java.util.HashSet;

import jacomma.icm.type.Message;
import jacomma.icm.type.Handle;

import jacomma.util.RdWrLock;
import jacomma.util.Environment;

/**
 * TBA
 **/
class MessageRouter implements MessageBuffer {
	
	Map agents_ = new HashMap();
	Map inp_ = new HashMap();
	Map outp_ = new HashMap();
	RdWrLock lock_ = new RdWrLock();
	InetAddress localhost_;

	static final MessageRouter instance = new MessageRouter();
	
	MessageRouter() {
		try {
			String cs = (String)Environment.getProperty( "icm.host" );
			localhost_ = ( cs == null ) ?
				InetAddress.getLocalHost() : InetAddress.getByName( cs );
		} catch ( java.net.UnknownHostException exc ) {
			throw new jacomma.util.CheckedException( exc );
		}
	}

	public void put( Message msg ) throws java.io.IOException {
		//route( msg ).put( msg );
		MessageBuffer target = route( msg );
		target.put( msg );
	}
	
	public void registerAgent( Handle h, MessageBuffer inp, MessageBuffer outp ) {
		lock_.wrlock();
		try {
			agents_.put( h.id(), localhost_ );
			inp_.put( h.id(), inp );
			outp_.put( h.id(), outp );
		} finally {
			lock_.unlock();
		}
	}
	
	public void unregisterAgent( Handle h ) {
		lock_.wrlock();
		try {
			agents_.remove( h.id() );
			inp_.remove( h.id() );
			outp_.remove( h.id() );
		} finally {
			lock_.unlock();
		}
	}

	public MessageBuffer route( Message msg ) {
		Handle to = msg.getRecipient();
		lock_.rdlock();
		try {
			if ( to.locations().contains( agents_.get( to.id() ) ) )
				return (MessageBuffer)inp_.get( to.id() );
			else
				return (MessageBuffer)outp_.get( msg.getSender().id() );
		} finally {
			lock_.unlock();
		}
	}
	
	public void dump() {
		System.out.println( toString() );
		System.out.println( "localhost: " + localhost_ );
		System.out.println( "agents: " + agents_ );
		System.out.println( "inp: " + inp_ );
		System.out.println( "outp: " + outp_ );
	}

}