001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.activemq.store;
018    
019    import java.io.IOException;
020    import java.util.concurrent.Callable;
021    import java.util.concurrent.Future;
022    import java.util.concurrent.FutureTask;
023    import org.apache.activemq.broker.ConnectionContext;
024    import org.apache.activemq.command.ActiveMQDestination;
025    import org.apache.activemq.command.Message;
026    import org.apache.activemq.command.MessageAck;
027    import org.apache.activemq.command.MessageId;
028    import org.apache.activemq.usage.MemoryUsage;
029    
030    abstract public class AbstractMessageStore implements MessageStore {
031        public static final FutureTask<Object> FUTURE;
032        protected final ActiveMQDestination destination;
033        protected boolean prioritizedMessages;
034    
035        public AbstractMessageStore(ActiveMQDestination destination) {
036            this.destination = destination;
037        }
038        
039        public void dispose(ConnectionContext context) {
040        }
041    
042        public void start() throws Exception {
043        }
044    
045        public void stop() throws Exception {
046        }
047    
048        public ActiveMQDestination getDestination() {
049            return destination;
050        }
051    
052        public void setMemoryUsage(MemoryUsage memoryUsage) {
053        }
054    
055        public void setBatch(MessageId messageId) throws IOException, Exception {
056        }
057    
058        /**
059         * flag to indicate if the store is empty
060         * 
061         * @return true if the message count is 0
062         * @throws Exception
063         */
064        public boolean isEmpty() throws Exception {
065            return getMessageCount() == 0;
066        }
067        
068        public void setPrioritizedMessages(boolean prioritizedMessages) {
069            this.prioritizedMessages = prioritizedMessages;
070        }    
071    
072        public boolean isPrioritizedMessages() {
073            return this.prioritizedMessages;
074        }
075    
076        public Future<Object> asyncAddQueueMessage(final ConnectionContext context, final Message message) throws IOException {
077            addMessage(context, message);
078            return FUTURE;
079        }
080    
081           
082        public Future<Object> asyncAddTopicMessage(final ConnectionContext context, final Message message) throws IOException {
083            addMessage(context, message);
084            return FUTURE;
085        }
086    
087        public void removeAsyncMessage(ConnectionContext context, MessageAck ack) throws IOException {
088            removeMessage(context, ack);
089        }
090        
091        static class CallableImplementation implements Callable<Object> {
092            public Object call() throws Exception {
093                return null;
094            }
095        }
096    
097        static {
098           FUTURE = new FutureTask<Object>(new CallableImplementation());
099           FUTURE.run();
100        }
101    }