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1   package org.apache.commons.jcs.utils.discovery;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.util.HashMap;
23  import java.util.Map;
24  
25  import org.apache.commons.jcs.engine.behavior.ICompositeCacheManager;
26  import org.apache.commons.jcs.engine.behavior.IProvideScheduler;
27  import org.apache.commons.logging.Log;
28  import org.apache.commons.logging.LogFactory;
29  
30  /**
31   * This manages UDPDiscovery Services. We should end up with one service per Lateral Cache Manager
32   * Instance. One service works for multiple regions. We don't want a connection for each region.
33   * <p>
34   * @author Aaron Smuts
35   */
36  public class UDPDiscoveryManager
37  {
38      /** The logger */
39      private static final Log log = LogFactory.getLog( UDPDiscoveryManager.class );
40  
41      /** Singleton instance */
42      private static UDPDiscoveryManager INSTANCE = new UDPDiscoveryManager();
43  
44      /** Known services */
45      private final Map<String, UDPDiscoveryService> services = new HashMap<String, UDPDiscoveryService>();
46  
47      /** private for singleton */
48      private UDPDiscoveryManager()
49      {
50          // noopt
51      }
52  
53      /**
54       * Singleton
55       * <p>
56       * @return UDPDiscoveryManager
57       */
58      public static UDPDiscoveryManager getInstance()
59      {
60          return INSTANCE;
61      }
62  
63      /**
64       * Creates a service for the address and port if one doesn't exist already.
65       * <p>
66       * We need to key this using the listener port too. TODO think of making one discovery service
67       * work for multiple types of clients.
68       * <p>
69       * @param discoveryAddress
70       * @param discoveryPort
71       * @param servicePort
72       * @param cacheMgr
73       * @return UDPDiscoveryService
74       */
75      public synchronized UDPDiscoveryService getService( String discoveryAddress, int discoveryPort, int servicePort,
76                                                          ICompositeCacheManager cacheMgr )
77      {
78          String key = discoveryAddress + ":" + discoveryPort + ":" + servicePort;
79  
80          UDPDiscoveryService service = services.get( key );
81          if ( service == null )
82          {
83              if ( log.isInfoEnabled() )
84              {
85                  log.info( "Creating service for address:port:servicePort [" + key + "]" );
86              }
87  
88              UDPDiscoveryAttributes attributes = new UDPDiscoveryAttributes();
89              attributes.setUdpDiscoveryAddr( discoveryAddress );
90              attributes.setUdpDiscoveryPort( discoveryPort );
91              attributes.setServicePort( servicePort );
92  
93              service = new UDPDiscoveryService( attributes );
94  
95              // register for shutdown notification
96              cacheMgr.registerShutdownObserver( service );
97  
98              // inject scheduler
99              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 }