/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.activemq.memory.list;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.activemq.broker.region.MessageReference;
import org.apache.activemq.broker.region.Subscription;
import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ActiveMQMessage;
import org.apache.activemq.command.Message;
import org.apache.activemq.filter.DestinationMap;
import org.apache.activemq.memory.buffer.MessageBuffer;
import org.apache.activemq.memory.buffer.MessageQueue;
import org.apache.activemq.memory.buffer.OrderBasedMessageBuffer;
/**
* An implementation of {@link MessageList} which maintains a separate message
* list for each destination to reduce contention on the list and to speed up
* recovery times by only recovering the interested topics.
*
*
*/
public class DestinationBasedMessageList implements MessageList {
private MessageBuffer messageBuffer;
private Map<ActiveMQDestination, MessageQueue> queueIndex = new HashMap<ActiveMQDestination, MessageQueue>();
private DestinationMap subscriptionIndex = new DestinationMap();
private Object lock = new Object();
public DestinationBasedMessageList(int maximumSize) {
this(new OrderBasedMessageBuffer(maximumSize));
}
public DestinationBasedMessageList(MessageBuffer buffer) {
messageBuffer = buffer;
}
public void add(MessageReference node) {
ActiveMQMessage message = (ActiveMQMessage) node.getMessageHardRef();
ActiveMQDestination destination = message.getDestination();
MessageQueue queue = null;
synchronized (lock) {
queue = queueIndex.get(destination);
if (queue == null) {
queue = messageBuffer.createMessageQueue();
queueIndex.put(destination, queue);
subscriptionIndex.put(destination, queue);
}
}
queue.add(node);
}
public List<MessageReference> getMessages(Subscription sub) {
return getMessages(sub.getConsumerInfo().getDestination());
}
public List<MessageReference> getMessages(ActiveMQDestination destination) {
Set set = null;
synchronized (lock) {
set = subscriptionIndex.get(destination);
}
List<MessageReference> answer = new ArrayList<MessageReference>();
for (Iterator iter = set.iterator(); iter.hasNext();) {
MessageQueue queue = (MessageQueue) iter.next();
queue.appendMessages(answer);
}
return answer;
}
public Message[] browse(ActiveMQDestination destination) {
List<MessageReference> result = getMessages(destination);
return result.toArray(new Message[result.size()]);
}
public void clear() {
messageBuffer.clear();
}
}