content: /**
   * 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;
  
  import org.apache.activemq.command.ConsumerId;
  import org.apache.activemq.command.Message;
  import org.apache.activemq.command.MessageId;
  
  /**
   * Keeps track of a message that is flowing through the Broker.  This 
   * object may hold a hard reference to the message or only hold the
   * id of the message if the message has been persisted on in a MessageStore.
   * 
   * 
   */
  public interface MessageReference {
      
      MessageId getMessageId();
      Message getMessageHardRef();
      Message getMessage();
      boolean isPersistent();
      
      Message.MessageDestination getRegionDestination();
      
      int getRedeliveryCounter();
      void incrementRedeliveryCounter();
      
      int getReferenceCount();
      
      int incrementReferenceCount();
      int decrementReferenceCount();
      ConsumerId getTargetConsumerId();
      int getSize();
      long getExpiration();
      String getGroupID();
      int getGroupSequence();
      
      /**
       * Returns true if this message is expired
       */
      boolean isExpired();
  
      /**
       * Returns true if this message is dropped.
       */
      boolean isDropped();
      
      /**
       * @return true if the message is an advisory
       */
      boolean isAdvisory();
  
      boolean canProcessAsExpired();
      
  }
  