001 /**
002 *
003 * Copyright 2004 Hiram Chirino
004 * Copyright 2004 Protique Ltd
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 *
018 **/
019 package org.activemq.store.cache;
020
021 import javax.jms.JMSException;
022
023 import org.activemq.message.ActiveMQMessage;
024 import org.activemq.message.MessageAck;
025 import org.activemq.service.MessageIdentity;
026 import org.activemq.store.MessageStore;
027 import org.activemq.store.RecoveryListener;
028
029 /**
030 * A MessageStore that uses an in memory cache to speed up getMessage() method calls.
031 *
032 * @version $Revision: 1.1.1.1 $
033 */
034 public class CacheMessageStore implements MessageStore, CacheMessageStoreAware {
035
036 private final MessageStore longTermStore;
037 private final MessageCache cache;
038
039 public CacheMessageStore(CachePersistenceAdapter adapter, MessageStore longTermStore, MessageCache cache) {
040 this.longTermStore = longTermStore;
041 this.cache = cache;
042
043 // Make any downstream CacheMessageStoreAware objects aware of us.
044 setCacheMessageStore(this);
045 }
046
047 /**
048 * Add the meessage to the long term store and cache it.
049 */
050 public void addMessage(ActiveMQMessage message) throws JMSException {
051 longTermStore.addMessage(message);
052 cache.put(message.getJMSMessageID(), message);
053 }
054
055 /**
056 * Remove the meessage to the long term store and remove it from the cache.
057 */
058 public void removeMessage(MessageAck ack) throws JMSException {
059 longTermStore.removeMessage( ack);
060 cache.remove(ack.getMessageID());
061 }
062
063 /**
064 * Return the message from the cache or go to the longTermStore if it is not
065 * in there.
066 */
067 public ActiveMQMessage getMessage(MessageIdentity identity) throws JMSException {
068 ActiveMQMessage answer=null;
069 answer = cache.get(identity.getMessageID());
070 if( answer!=null )
071 return answer;
072
073 answer = longTermStore.getMessage(identity);
074 cache.put(identity.getMessageID(), answer);
075 return answer;
076 }
077
078 /**
079 * Replays the checkpointStore first as those messages are the oldest ones,
080 * then messages are replayed from the transaction log and then the cache is
081 * updated.
082 *
083 * @param listener
084 * @throws JMSException
085 */
086 public synchronized void recover(final RecoveryListener listener)
087 throws JMSException {
088 longTermStore.recover(listener);
089 }
090
091 public void start() throws JMSException {
092 longTermStore.start();
093 }
094
095 public void stop() throws JMSException {
096 longTermStore.stop();
097 cache.close();
098 }
099
100 /**
101 * @return Returns the longTermStore.
102 */
103 public MessageStore getLongTermStore() {
104 return longTermStore;
105 }
106
107 /**
108 * @see org.activemq.store.cache.CacheMessageStoreAware#setCacheMessageStore(org.activemq.store.cache.CacheMessageStore)
109 */
110 public void setCacheMessageStore(CacheMessageStore store) {
111 // Make any downstream CacheMessageStoreAware objects aware of us.
112 // This cache implementation could be cached by another cache.
113 if( longTermStore instanceof CacheMessageStoreAware ) {
114 ((CacheMessageStoreAware)longTermStore).setCacheMessageStore(store);
115 }
116 }
117
118 /**
119 * @see org.activemq.store.MessageStore#removeAllMessages()
120 */
121 public void removeAllMessages() throws JMSException {
122 longTermStore.removeAllMessages();
123 }
124
125
126 }