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 */
017package org.apache.activemq.network;
018
019import java.io.IOException;
020
021import org.apache.activemq.command.BrokerId;
022import org.apache.activemq.command.BrokerInfo;
023import org.apache.activemq.command.Command;
024import org.apache.activemq.command.ConsumerInfo;
025import org.apache.activemq.command.Endpoint;
026import org.apache.activemq.command.NetworkBridgeFilter;
027import org.apache.activemq.transport.Transport;
028import org.apache.activemq.util.ServiceSupport;
029import org.slf4j.Logger;
030import org.slf4j.LoggerFactory;
031
032/**
033 * A demand forwarding bridge which works with multicast style transports where
034 * a single Transport could be communicating with multiple remote brokers
035 * 
036 * @org.apache.xbean.XBean
037 * 
038 * 
039 */
040public class CompositeDemandForwardingBridge extends DemandForwardingBridgeSupport {
041    private static final Logger LOG = LoggerFactory.getLogger(CompositeDemandForwardingBridge.class);
042
043    protected final BrokerId remoteBrokerPath[] = new BrokerId[] {null};
044    protected Object brokerInfoMutex = new Object();
045
046    public CompositeDemandForwardingBridge(NetworkBridgeConfiguration configuration, Transport localBroker,
047                                           Transport remoteBroker) {
048        super(configuration, localBroker, remoteBroker);
049        remoteBrokerName = remoteBroker.toString();
050        remoteBrokerNameKnownLatch.countDown();
051    }
052
053    protected void serviceRemoteBrokerInfo(Command command) throws IOException {
054        synchronized (brokerInfoMutex) {
055            BrokerInfo remoteBrokerInfo = (BrokerInfo)command;
056            BrokerId remoteBrokerId = remoteBrokerInfo.getBrokerId();
057
058            // lets associate the incoming endpoint with a broker ID so we can
059            // refer to it later
060            Endpoint from = command.getFrom();
061            if (from == null) {
062                LOG.warn("Incoming command does not have a from endpoint: " + command);
063            } else {
064                from.setBrokerInfo(remoteBrokerInfo);
065            }
066            if (localBrokerId != null) {
067                if (localBrokerId.equals(remoteBrokerId)) {
068                    LOG.info("Disconnecting loop back connection.");
069                    // waitStarted();
070                    ServiceSupport.dispose(this);
071                }
072            }
073            if (!disposed.get()) {
074                triggerLocalStartBridge();
075            }
076        }
077    }
078
079    protected void addRemoteBrokerToBrokerPath(ConsumerInfo info) throws IOException {
080        info.setBrokerPath(appendToBrokerPath(info.getBrokerPath(), getFromBrokerId(info)));
081    }
082
083    /**
084     * Returns the broker ID that the command came from
085     */
086    protected BrokerId getFromBrokerId(Command command) throws IOException {
087        BrokerId answer = null;
088        Endpoint from = command.getFrom();
089        if (from == null) {
090            LOG.warn("Incoming command does not have a from endpoint: " + command);
091        } else {
092            answer = from.getBrokerId();
093        }
094        if (answer != null) {
095            return answer;
096        } else {
097            throw new IOException("No broker ID is available for endpoint: " + from + " from command: "
098                                  + command);
099        }
100    }
101
102    protected void serviceLocalBrokerInfo(Command command) throws InterruptedException {
103        // TODO is there much we can do here?
104    }
105
106    protected NetworkBridgeFilter createNetworkBridgeFilter(ConsumerInfo info) throws IOException {
107        return new NetworkBridgeFilter(getFromBrokerId(info), configuration.getNetworkTTL());
108    }
109
110    protected BrokerId[] getRemoteBrokerPath() {
111        return remoteBrokerPath;
112    }
113
114}