001    /** 
002     * 
003     * Copyright 2004 Hiram Chirino
004     * 
005     * Licensed under the Apache License, Version 2.0 (the "License"); 
006     * you may not use this file except in compliance with the License. 
007     * 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     **/
018    package org.activemq.store.cache;
019    
020    import org.activemq.message.ActiveMQMessage;
021    
022    /**
023     * Defines the interface used to cache messages.
024     *
025     * @version $Revision: 1.1.1.1 $
026     */
027    public interface MessageCache {
028            /**
029             * Gets a message that was previously <code>put</code> into this object.   
030             * 
031             * @param msgid
032             * @return null if the message was not previously put or if the message has expired out of the cache.
033             */
034            public ActiveMQMessage get(String msgid);
035    
036            /**
037             * Puts a message into the cache.
038             * 
039             * @param messageID
040             * @param message
041             */
042            public void put(String messageID, ActiveMQMessage message);
043    
044            /**
045             * Remvoes a message from the cache.
046             * 
047             * @param messageID
048             */
049            public void remove(String messageID);
050    
051        /**
052         * Lets a cache know it will not be used any further and that it can release 
053         * aquired resources
054         */
055        public void close();
056            
057    }