org.apache.activemq.FifoMessageDispatchChannel Maven / Gradle / Ivy
/**
* 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;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import org.apache.activemq.command.MessageDispatch;
public class FifoMessageDispatchChannel implements MessageDispatchChannel {
private final Object mutex = new Object();
private final LinkedList list;
private boolean closed;
private boolean running;
public FifoMessageDispatchChannel() {
this.list = new LinkedList();
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#enqueue(org.apache.activemq.command.MessageDispatch)
*/
public void enqueue(MessageDispatch message) {
synchronized (mutex) {
list.addLast(message);
mutex.notify();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#enqueueFirst(org.apache.activemq.command.MessageDispatch)
*/
public void enqueueFirst(MessageDispatch message) {
synchronized (mutex) {
list.addFirst(message);
mutex.notify();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#isEmpty()
*/
public boolean isEmpty() {
synchronized (mutex) {
return list.isEmpty();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#dequeue(long)
*/
public MessageDispatch dequeue(long timeout) throws InterruptedException {
synchronized (mutex) {
// Wait until the consumer is ready to deliver messages.
while (timeout != 0 && !closed && (list.isEmpty() || !running)) {
if (timeout == -1) {
mutex.wait();
} else {
mutex.wait(timeout);
break;
}
}
if (closed || !running || list.isEmpty()) {
return null;
}
return list.removeFirst();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#dequeueNoWait()
*/
public MessageDispatch dequeueNoWait() {
synchronized (mutex) {
if (closed || !running || list.isEmpty()) {
return null;
}
return list.removeFirst();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#peek()
*/
public MessageDispatch peek() {
synchronized (mutex) {
if (closed || !running || list.isEmpty()) {
return null;
}
return list.getFirst();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#start()
*/
public void start() {
synchronized (mutex) {
running = true;
mutex.notifyAll();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#stop()
*/
public void stop() {
synchronized (mutex) {
running = false;
mutex.notifyAll();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#close()
*/
public void close() {
synchronized (mutex) {
if (!closed) {
running = false;
closed = true;
}
mutex.notifyAll();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#clear()
*/
public void clear() {
synchronized (mutex) {
list.clear();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#isClosed()
*/
public boolean isClosed() {
return closed;
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#size()
*/
public int size() {
synchronized (mutex) {
return list.size();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#getMutex()
*/
public Object getMutex() {
return mutex;
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#isRunning()
*/
public boolean isRunning() {
return running;
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#removeAll()
*/
public List removeAll() {
synchronized (mutex) {
ArrayList rc = new ArrayList(list);
list.clear();
return rc;
}
}
@Override
public String toString() {
synchronized (mutex) {
return list.toString();
}
}
}