Cache.java

package org.apache.blur.store.blockcache;

/**
 * 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.
 */

/**
 * 
 */
public interface Cache {

  /**
   * Remove a file from the cache.
   * 
   * @param name cache file name
   */
  void delete(String name);

  /**
   * Update the content of the specified cache file. Creates cache entry
   * if necessary.
   * 
   */
  void update(String name, long blockId, int blockOffset, byte[] buffer, int offset, int length);
  
  /**
   * Fetch the specified cache file content.
   *
   * @return true if cached content found, otherwise return false
   */
  boolean fetch(String name, long blockId, int blockOffset, byte[] b, int off, int lengthToReadInBlock);

  /**
   * Number of entries in the cache.
   */
  long size();

  /**
   * Expert: Rename the specified file in the cache. Allows a file to be moved
   * without invalidating the cache.
   * 
   * @param source original name
   * @param dest final name
   */
  void renameCacheFile(String source, String dest);

}