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.broker.region;
018    
019    import org.apache.activemq.command.ConsumerId;
020    import org.apache.activemq.command.Message;
021    import org.apache.activemq.command.MessageId;
022    
023    /**
024     * Keeps track of a message that is flowing through the Broker.  This 
025     * object may hold a hard reference to the message or only hold the
026     * id of the message if the message has been persisted on in a MessageStore.
027     * 
028     * 
029     */
030    public interface MessageReference {
031        
032        MessageId getMessageId();
033        Message getMessageHardRef();
034        Message getMessage();
035        boolean isPersistent();
036        
037        Message.MessageDestination getRegionDestination();
038        
039        int getRedeliveryCounter();
040        void incrementRedeliveryCounter();
041        
042        int getReferenceCount();
043        
044        int incrementReferenceCount();
045        int decrementReferenceCount();
046        ConsumerId getTargetConsumerId();
047        int getSize();
048        long getExpiration();
049        String getGroupID();
050        int getGroupSequence();
051        
052        /**
053         * Returns true if this message is expired
054         */
055        boolean isExpired();
056    
057        /**
058         * Returns true if this message is dropped.
059         */
060        boolean isDropped();
061        
062        /**
063         * @return true if the message is an advisory
064         */
065        boolean isAdvisory();
066        
067    }