abstracttrimmingcache.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Ozone Core License version 1 published by ozone-db.org.
//
// Copyright (C) 2003-@year@, Leo Mekenkamp. All rights reserved.
//
// $Id: AbstractTrimmingCache.java,v 1.1.2.2 2004/04/10 10:06:51 per_nyfelt Exp $

package org.ozoneDB.core.storage;

import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.Map.Entry;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.ozoneDB.OzoneInternalException;
import org.ozoneDB.core.ConfigurationException;


/**
 * @author <a href="mailto:leoATmekenkampD0Tcom">Leo Mekenkamp (mind the anti sp@m)</a>
 * @version $Id: AbstractTrimmingCache.java,v 1.1.2.2 2004/04/10 10:06:51 per_nyfelt Exp $
 */
public abstract class AbstractTrimmingCache implements TrimmingCache, PropertyConfigurable {
    
    private static final Logger log = Logger.getLogger(AbstractTrimmingCache.class.getName());

    private Object synchronizer;
    private TrimHandler trimHandler;
    private String prefix;
    
    public AbstractTrimmingCache(Properties properties, String prefix) {
        setSynchronizer(null); // use default object for synchronization
        this.prefix = prefix;
    }

    public final String getPrefix() {
        return prefix;
    }
    
    /**
     * Because of performance issues caller _must_ ensure that no other thread
     * has got a reference to <code>getSynchronizer()</code>.
     */
    public final void setSynchronizer(Object synchronizer) {
        this.synchronizer = synchronizer != null ? synchronizer : this;
    }
    
    public final Object getSynchronizer() {
         return synchronizer;
    }
    
    public final TrimmingCache.TrimHandler getTrimHandler() {
        return trimHandler;
    }
    
    public final void setTrimHandler(TrimmingCache.TrimHandler trimHandler) {
        this.trimHandler = trimHandler;
    }
    
    public Collection getPropertyInfos() {
        return new LinkedList();
    }
    
}