| /** |
| * 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 SimplePriorityMessageDispatchChannel implements MessageDispatchChannel { |
| private static final Integer MAX_PRIORITY = 10; |
| private final Object mutex = new Object(); |
| private final LinkedList<MessageDispatch>[] lists; |
| private boolean closed; |
| private boolean running; |
| private int size = 0; |
| |
| @SuppressWarnings("unchecked") |
| public SimplePriorityMessageDispatchChannel() { |
| this.lists = new LinkedList[MAX_PRIORITY]; |
| for (int i = 0; i < MAX_PRIORITY; i++) { |
| lists[i] = new LinkedList<MessageDispatch>(); |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#enqueue(org.apache.activemq.command.MessageDispatch) |
| */ |
| @Override |
| public void enqueue(MessageDispatch message) { |
| synchronized (mutex) { |
| getList(message).addLast(message); |
| this.size++; |
| mutex.notify(); |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#enqueueFirst(org.apache.activemq.command.MessageDispatch) |
| */ |
| @Override |
| public void enqueueFirst(MessageDispatch message) { |
| synchronized (mutex) { |
| getList(message).addFirst(message); |
| this.size++; |
| mutex.notify(); |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#isEmpty() |
| */ |
| @Override |
| public boolean isEmpty() { |
| return this.size == 0; |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#dequeue(long) |
| */ |
| @Override |
| public MessageDispatch dequeue(long timeout) throws InterruptedException { |
| synchronized (mutex) { |
| // Wait until the consumer is ready to deliver messages. |
| while (timeout != 0 && !closed && (isEmpty() || !running)) { |
| if (timeout == -1) { |
| mutex.wait(); |
| } else { |
| mutex.wait(timeout); |
| break; |
| } |
| } |
| if (closed || !running || isEmpty()) { |
| return null; |
| } |
| return removeFirst(); |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#dequeueNoWait() |
| */ |
| @Override |
| public MessageDispatch dequeueNoWait() { |
| synchronized (mutex) { |
| if (closed || !running || isEmpty()) { |
| return null; |
| } |
| return removeFirst(); |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#peek() |
| */ |
| @Override |
| public MessageDispatch peek() { |
| synchronized (mutex) { |
| if (closed || !running || isEmpty()) { |
| return null; |
| } |
| return getFirst(); |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#start() |
| */ |
| @Override |
| public void start() { |
| synchronized (mutex) { |
| running = true; |
| mutex.notifyAll(); |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#stop() |
| */ |
| @Override |
| public void stop() { |
| synchronized (mutex) { |
| running = false; |
| mutex.notifyAll(); |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#close() |
| */ |
| @Override |
| public void close() { |
| synchronized (mutex) { |
| if (!closed) { |
| running = false; |
| closed = true; |
| } |
| mutex.notifyAll(); |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#clear() |
| */ |
| @Override |
| public void clear() { |
| synchronized (mutex) { |
| for (int i = 0; i < MAX_PRIORITY; i++) { |
| lists[i].clear(); |
| } |
| this.size = 0; |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#isClosed() |
| */ |
| @Override |
| public boolean isClosed() { |
| return closed; |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#size() |
| */ |
| @Override |
| public int size() { |
| synchronized (mutex) { |
| return this.size; |
| } |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#getMutex() |
| */ |
| @Override |
| public Object getMutex() { |
| return mutex; |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#isRunning() |
| */ |
| @Override |
| public boolean isRunning() { |
| return running; |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.activemq.MessageDispatchChannelI#removeAll() |
| */ |
| @Override |
| public List<MessageDispatch> removeAll() { |
| synchronized (mutex) { |
| ArrayList<MessageDispatch> result = new ArrayList<MessageDispatch>(size()); |
| for (int i = MAX_PRIORITY - 1; i >= 0; i--) { |
| List<MessageDispatch> list = lists[i]; |
| result.addAll(list); |
| size -= list.size(); |
| list.clear(); |
| } |
| return result; |
| } |
| } |
| |
| @Override |
| public String toString() { |
| String result = ""; |
| for (int i = MAX_PRIORITY - 1; i >= 0; i--) { |
| result += i + ":{" + lists[i].toString() + "}"; |
| } |
| return result; |
| } |
| |
| protected int getPriority(MessageDispatch message) { |
| int priority = javax.jms.Message.DEFAULT_PRIORITY; |
| if (message.getMessage() != null) { |
| priority = Math.max(message.getMessage().getPriority(), 0); |
| priority = Math.min(priority, 9); |
| } |
| return priority; |
| } |
| |
| protected LinkedList<MessageDispatch> getList(MessageDispatch md) { |
| return lists[getPriority(md)]; |
| } |
| |
| private final MessageDispatch removeFirst() { |
| if (this.size > 0) { |
| for (int i = MAX_PRIORITY - 1; i >= 0; i--) { |
| LinkedList<MessageDispatch> list = lists[i]; |
| if (!list.isEmpty()) { |
| this.size--; |
| return list.removeFirst(); |
| } |
| } |
| } |
| return null; |
| } |
| |
| private final MessageDispatch getFirst() { |
| if (this.size > 0) { |
| for (int i = MAX_PRIORITY - 1; i >= 0; i--) { |
| LinkedList<MessageDispatch> list = lists[i]; |
| if (!list.isEmpty()) { |
| return list.getFirst(); |
| } |
| } |
| } |
| return null; |
| } |
| } |