001package org.apache.commons.jcs.utils.discovery;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import java.util.HashMap;
023import java.util.Map;
024
025import org.apache.commons.jcs.engine.behavior.ICompositeCacheManager;
026import org.apache.commons.jcs.engine.behavior.IProvideScheduler;
027import org.apache.commons.logging.Log;
028import org.apache.commons.logging.LogFactory;
029
030/**
031 * This manages UDPDiscovery Services. We should end up with one service per Lateral Cache Manager
032 * Instance. One service works for multiple regions. We don't want a connection for each region.
033 * <p>
034 * @author Aaron Smuts
035 */
036public class UDPDiscoveryManager
037{
038    /** The logger */
039    private static final Log log = LogFactory.getLog( UDPDiscoveryManager.class );
040
041    /** Singleton instance */
042    private static UDPDiscoveryManager INSTANCE = new UDPDiscoveryManager();
043
044    /** Known services */
045    private final Map<String, UDPDiscoveryService> services = new HashMap<String, UDPDiscoveryService>();
046
047    /** private for singleton */
048    private UDPDiscoveryManager()
049    {
050        // noopt
051    }
052
053    /**
054     * Singleton
055     * <p>
056     * @return UDPDiscoveryManager
057     */
058    public static UDPDiscoveryManager getInstance()
059    {
060        return INSTANCE;
061    }
062
063    /**
064     * Creates a service for the address and port if one doesn't exist already.
065     * <p>
066     * We need to key this using the listener port too. TODO think of making one discovery service
067     * work for multiple types of clients.
068     * <p>
069     * @param discoveryAddress
070     * @param discoveryPort
071     * @param servicePort
072     * @param cacheMgr
073     * @return UDPDiscoveryService
074     */
075    public synchronized UDPDiscoveryService getService( String discoveryAddress, int discoveryPort, int servicePort,
076                                                        ICompositeCacheManager cacheMgr )
077    {
078        String key = discoveryAddress + ":" + discoveryPort + ":" + servicePort;
079
080        UDPDiscoveryService service = services.get( key );
081        if ( service == null )
082        {
083            if ( log.isInfoEnabled() )
084            {
085                log.info( "Creating service for address:port:servicePort [" + key + "]" );
086            }
087
088            UDPDiscoveryAttributes attributes = new UDPDiscoveryAttributes();
089            attributes.setUdpDiscoveryAddr( discoveryAddress );
090            attributes.setUdpDiscoveryPort( discoveryPort );
091            attributes.setServicePort( servicePort );
092
093            service = new UDPDiscoveryService( attributes );
094
095            // register for shutdown notification
096            cacheMgr.registerShutdownObserver( service );
097
098            // inject scheduler
099            if ( cacheMgr instanceof IProvideScheduler)
100            {
101                service.setScheduledExecutorService(((IProvideScheduler)cacheMgr).getScheduledExecutorService());
102            }
103
104            service.startup();
105            services.put( key, service );
106        }
107
108        if ( log.isDebugEnabled() )
109        {
110            log.debug( "Returning service [" + service + "] for key [" + key + "]" );
111        }
112
113        return service;
114    }
115}