Cachable.java

/**
 * Copyright (c) 2003-2009, Xith3D Project Group all rights reserved.
 * 
 * Portions based on the Java3D interface, Copyright by Sun Microsystems.
 * Many thanks to the developers of Java3D and Sun Microsystems for their
 * innovation and design.
 * 
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 * 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,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the 'Xith3D Project Group' 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 org.xith3d.utility.cache;

import org.jagatoo.datatypes.NamedObject;

/**
 * Optional interface which allows the caching system to better report
 * and manage the items being cached.
 * 
 * @author David Yazel
 */
public interface Cachable< T > extends NamedObject
{
    /**
     * @return an approximate amount of memory being used by the cached item.
     */
    long memoryUsed();
    
    /**
     * Called if the cache determines that the object should be flushed through
     * non-use.  This should only be called be the caching system if check in and
     * check out are strictly managed.  The the implementation does nothing in this
     * function then the object will be garbaged collected.
     * 
     * @param o
     */
    void flush( T o );
    
    /**
     * @return the name of the cached object. Returning NULL is acceptable. This
     * is primarily used for reporting and tracking cached items.
     */
    String getName();
}