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.store;
  
  import java.io.IOException;
  import java.util.concurrent.locks.Lock;
  
  import org.apache.activemq.broker.ConnectionContext;
  import org.apache.activemq.command.MessageId;
  
  /**
   * Represents a message store which is used by the persistent implementations
   * 
   * 
   */
  public interface ReferenceStore extends MessageStore {
  
      public class ReferenceData {
          long expiration;
          int fileId;
          int offset;
  
          public long getExpiration() {
              return expiration;
          }
  
          public void setExpiration(long expiration) {
              this.expiration = expiration;
          }
  
          public int getFileId() {
              return fileId;
          }
  
          public void setFileId(int file) {
              this.fileId = file;
          }
  
          public int getOffset() {
              return offset;
          }
  
          public void setOffset(int offset) {
              this.offset = offset;
          }
  
          @Override
          public String toString() {
              return "ReferenceData fileId=" + fileId + ", offset=" + offset + ", expiration=" + expiration;
          }
      }
  
      /**
       * Adds a message reference to the message store
       * @return true if reference was added, false if it is a duplicate and not added
       */
      boolean addMessageReference(ConnectionContext context, MessageId messageId, ReferenceData data) throws IOException;
  
      /**
       * Looks up a message using either the String messageID or the
       * messageNumber. Implementations are encouraged to fill in the missing key
       * if its easy to do so.
       */
      ReferenceData getMessageReference(MessageId identity) throws IOException;
  
      /**
       * @return true if it supports external batch control
       */
      boolean supportsExternalBatchControl();
  
      void setBatch(MessageId startAfter);
      
      Lock getStoreLock();
      
  }
  