001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.activemq.network;
018    
019    import java.io.IOException;
020    
021    import org.apache.activemq.command.BrokerId;
022    import org.apache.activemq.command.BrokerInfo;
023    import org.apache.activemq.command.Command;
024    import org.apache.activemq.command.ConsumerInfo;
025    import org.apache.activemq.command.NetworkBridgeFilter;
026    import org.apache.activemq.transport.Transport;
027    import org.apache.activemq.util.ServiceSupport;
028    import org.apache.commons.logging.Log;
029    import org.apache.commons.logging.LogFactory;
030    
031    /**
032     * Forwards messages from the local broker to the remote broker based on demand.
033     * 
034     * @org.apache.xbean.XBean
035     * 
036     * @version $Revision$
037     */
038    public class DemandForwardingBridge extends DemandForwardingBridgeSupport {
039        private static final Log LOG = LogFactory.getLog(DemandForwardingBridge.class);
040    
041        protected final BrokerId remoteBrokerPath[] = new BrokerId[] {null};
042        protected Object brokerInfoMutex = new Object();
043        protected BrokerId remoteBrokerId;
044    
045        public DemandForwardingBridge(NetworkBridgeConfiguration configuration, Transport localBroker,
046                                      Transport remoteBroker) {
047            super(configuration, localBroker, remoteBroker);
048        }
049    
050        protected void serviceRemoteBrokerInfo(Command command) throws IOException {
051            synchronized (brokerInfoMutex) {
052                BrokerInfo remoteBrokerInfo = (BrokerInfo)command;
053                remoteBrokerId = remoteBrokerInfo.getBrokerId();
054                remoteBrokerPath[0] = remoteBrokerId;
055                remoteBrokerName = remoteBrokerInfo.getBrokerName();
056                if (localBrokerId != null) {
057                    if (localBrokerId.equals(remoteBrokerId)) {
058                        if (LOG.isTraceEnabled()) {
059                            LOG.trace(configuration.getBrokerName() + " disconnecting remote loop back connection: " + remoteBrokerName);
060                        }
061                        ServiceSupport.dispose(this);
062                    }
063                }
064                if (LOG.isTraceEnabled()) {
065                    LOG.trace("counting down remoteBrokerNameKnownLatch with: " + command);
066                }
067                remoteBrokerNameKnownLatch.countDown();
068            }
069        }
070    
071        protected void addRemoteBrokerToBrokerPath(ConsumerInfo info) {
072            info.setBrokerPath(appendToBrokerPath(info.getBrokerPath(), getRemoteBrokerPath()));
073        }
074    
075        protected void serviceLocalBrokerInfo(Command command) throws InterruptedException {
076            synchronized (brokerInfoMutex) {
077                localBrokerId = ((BrokerInfo)command).getBrokerId();
078                localBrokerPath[0] = localBrokerId;
079                localBrokerIdKnownLatch.countDown();
080                if (remoteBrokerId != null) {
081                    if (remoteBrokerId.equals(localBrokerId)) {
082                        if (LOG.isTraceEnabled()) {
083                            LOG.trace(configuration.getBrokerName() + " disconnecting local loop back connection.");
084                        }
085                        waitStarted();
086                        ServiceSupport.dispose(this);
087                    }
088                }
089            }
090        }
091    
092        protected NetworkBridgeFilter createNetworkBridgeFilter(ConsumerInfo info) throws IOException {
093            return new NetworkBridgeFilter(remoteBrokerPath[0], configuration.getNetworkTTL());
094        }
095    
096        protected BrokerId[] getRemoteBrokerPath() {
097            return remoteBrokerPath;
098        }
099    }