cachecallback.java

实现数据库的storage manager 功能

/*
 * Copyright (c) 2000-2004, Rickard C鰏ter, Martin Svensson
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * 
 * Redistributions of source code must retain the above copyright notice, 
 * this list of conditions and the following disclaimer. 
 * Redistributions in binary form must reproduce the above copyright notice, 
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 * and/or other materials provided with the distribution. 
 * Neither the name of SICS nor the names of its contributors 
 * may be used to endorse or promote products derived from this software 
 * without specific prior written permission. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
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package com.mellowtech.disc;


/**
 * The CacheCallback is used as the callback function when the
 * various caches remove a key/value from their cache.
 * @author Martin Svensson
 * @version 1.0
 */
public interface CacheCallback{

  /**
   * Operation to perform on a key/value pair that just has been
   * remove from a cache. e.g, if the cache is used to keep often
   * accecced values in memory instead of on disc, this method should
   * store the key/value back to disc to keep the changes made in
   * the cache.
   * @param key a value of type 'Object'
   * @param value the CacheValue object indicates wheater the value has changed
   */
  public void remove(Object key, Object value);
}