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.NetworkBridgeFilter;
026import org.apache.activemq.transport.Transport;
027import org.apache.activemq.util.ServiceSupport;
028import org.slf4j.Logger;
029import org.slf4j.LoggerFactory;
030
031/**
032 * Forwards messages from the local broker to the remote broker based on demand.
033 * 
034 * @org.apache.xbean.XBean
035 * 
036 * 
037 */
038public class DemandForwardingBridge extends DemandForwardingBridgeSupport {
039    private static final Logger LOG = LoggerFactory.getLogger(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}