| /** |
| * 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.broker.region; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| |
| import javax.jms.JMSException; |
| |
| import org.apache.activemq.broker.Broker; |
| import org.apache.activemq.broker.ConnectionContext; |
| import org.apache.activemq.command.ConsumerInfo; |
| import org.apache.activemq.command.MessageAck; |
| import org.apache.activemq.command.MessageId; |
| import org.apache.activemq.filter.MessageEvaluationContext; |
| import org.apache.activemq.usage.SystemUsage; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class QueueBrowserSubscription extends QueueSubscription { |
| |
| protected static final Logger LOG = LoggerFactory.getLogger(QueueBrowserSubscription.class); |
| |
| int queueRefs; |
| boolean browseDone; |
| boolean destinationsAdded; |
| |
| private final ConcurrentMap<MessageId, Object> audit = new ConcurrentHashMap<MessageId, Object>(); |
| private long maxMessages; |
| |
| public QueueBrowserSubscription(Broker broker, SystemUsage usageManager, ConnectionContext context, ConsumerInfo info) throws JMSException { |
| super(broker, usageManager, context, info); |
| } |
| |
| @Override |
| protected boolean canDispatch(MessageReference node) { |
| return !((QueueMessageReference) node).isAcked(); |
| } |
| |
| @Override |
| public synchronized String toString() { |
| return "QueueBrowserSubscription:" + " consumer=" + info.getConsumerId() + |
| ", destinations=" + destinations.size() + ", dispatched=" + dispatched.size() + |
| ", delivered=" + this.prefetchExtension + ", pending=" + getPendingQueueSize(); |
| } |
| |
| synchronized public void destinationsAdded() throws Exception { |
| destinationsAdded = true; |
| checkDone(); |
| } |
| |
| public boolean isDuplicate(MessageId messageId) { |
| return audit.putIfAbsent(messageId, Boolean.TRUE) != null; |
| } |
| |
| private void checkDone() throws Exception { |
| if (!browseDone && queueRefs == 0 && destinationsAdded) { |
| browseDone = true; |
| add(QueueMessageReference.NULL_MESSAGE); |
| } |
| } |
| |
| @Override |
| public boolean matches(MessageReference node, MessageEvaluationContext context) throws IOException { |
| return !browseDone && super.matches(node, context); |
| } |
| |
| /** |
| * Since we are a browser we don't really remove the message from the queue. |
| */ |
| @Override |
| protected void acknowledge(ConnectionContext context, final MessageAck ack, final MessageReference n) throws IOException { |
| if (info.isNetworkSubscription()) { |
| super.acknowledge(context, ack, n); |
| } |
| } |
| |
| synchronized public void incrementQueueRef() { |
| queueRefs++; |
| } |
| |
| synchronized public void decrementQueueRef() throws Exception { |
| if (queueRefs > 0) { |
| queueRefs--; |
| } |
| checkDone(); |
| } |
| |
| @Override |
| public List<MessageReference> remove(ConnectionContext context, Destination destination) throws Exception { |
| super.remove(context, destination); |
| // there's no unacked messages that needs to be redelivered |
| // in case of browser |
| return new ArrayList<MessageReference>(); |
| } |
| |
| public boolean atMax() { |
| return maxMessages > 0 && getEnqueueCounter() >= maxMessages; |
| } |
| |
| public void setMaxMessages(long max) { |
| maxMessages = max; |
| } |
| } |