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.policy;
  
  
  import org.apache.activemq.Service;
  import org.apache.activemq.broker.Broker;
  import org.apache.activemq.broker.ConnectionContext;
  import org.apache.activemq.broker.region.MessageReference;
  import org.apache.activemq.broker.region.SubscriptionRecovery;
  import org.apache.activemq.broker.region.Topic;
  import org.apache.activemq.command.ActiveMQDestination;
  import org.apache.activemq.command.Message;
  
  /**
   * Abstraction to allow different recovery policies to be plugged
   * into the region implementations.  This is used by a topic to retroactively recover
   * messages that the subscription missed.
   * 
   * 
   */
  public interface SubscriptionRecoveryPolicy extends Service {
      
      /**
       * A message was sent to the destination.
       * 
       * @param context
       * @param message
       * @return true if successful
       * @throws Exception
       */
      boolean add(ConnectionContext context, MessageReference message) throws Exception;
      
      /**
       * Let a subscription recover message held by the policy.
       * 
       * @param context
       * @param topic
       * @param sub
       * @throws Exception
       */
      void recover(ConnectionContext context, Topic topic, SubscriptionRecovery sub) throws Exception;
      
      
      /**
       * @param dest 
       * @return messages
       * @throws Exception 
       */
      Message[] browse(ActiveMQDestination dest) throws Exception;
  
      /**
       * Used to copy the policy object.
       * @return the copy
       */
      SubscriptionRecoveryPolicy copy();
      
      void setBroker(Broker broker);
  }
  