trunk/activemq-core/src/main/java/org/apache/activemq/broker/region/QueueMessageReference.java

/**
 * 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.broker.region;

/**
 * Queue specific MessageReference.
 * 
 * @author fateev@amazon.com
 * 
 */
public interface QueueMessageReference extends MessageReference {

    QueueMessageReference NULL_MESSAGE = new NullMessageReference();

    boolean isAcked();
    
    void setAcked(boolean b);
    
    void drop();
 
    boolean isDropped();
        
    boolean lock(LockOwner subscription);
    
    boolean unlock();
    
    LockOwner getLockOwner();
}