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/**
* 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 javax.jms.InvalidSelectorException;
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.filter.MessageEvaluationContext;
import org.apache.activemq.usage.SystemUsage;
public class QueueBrowserSubscription extends QueueSubscription {
int queueRefs;
boolean browseDone;
boolean destinationsAdded;
public QueueBrowserSubscription(Broker broker,SystemUsage usageManager, ConnectionContext context, ConsumerInfo info)
throws InvalidSelectorException {
super(broker,usageManager, context, info);
}
protected boolean canDispatch(MessageReference node) {
return !((QueueMessageReference)node).isAcked();
}
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();
}
private void checkDone() throws Exception {
if( !browseDone && queueRefs == 0 && destinationsAdded) {
browseDone=true;
add(QueueMessageReference.NULL_MESSAGE);
}
}
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.
*/
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 {
queueRefs--;
checkDone();
}
}