/*
 * Copyright (C) 2005-2007 Alfresco Software Limited.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 * As a special exception to the terms and conditions of version 2.0 of 
 * the GPL, you may redistribute this Program in connection with Free/Libre 
 * and Open Source Software ("FLOSS") applications as described in Alfresco's 
 * FLOSS exception.  You should have recieved a copy of the text describing 
 * the FLOSS exception, and it is also available here: 
 * http://www.alfresco.com/legal/licensing"
 */
package org.alfresco.repo.cache;

import java.io.Serializable;
import java.util.Collection;

import net.sf.ehcache.Cache;
import net.sf.ehcache.CacheException;
import net.sf.ehcache.Element;

import org.alfresco.error.AlfrescoRuntimeException;

/**
 * A thin adapter for <b>Ehcache</b> support.
 * <p>
 * Thread-safety is taken care of by the underlying <b>Ehcache</b>
 * instance.
 *
 * @see org.springframework.cache.ehcache.EhCacheFactoryBean
 * @see org.springframework.cache.ehcache.EhCacheManagerFactoryBean
 * 
 * @author Derek Hulley
 */
public class EhCacheAdapter<K extends Serializable, V extends Serializable>
        implements SimpleCache<K, V>
{
    private net.sf.ehcache.Cache cache;
    
    public EhCacheAdapter()
    {
    }

    /**
     * @param cache the backing Ehcache instance
     */
    public void setCache(Cache cache)
    {
        this.cache = cache;
    }

    public boolean contains(K key)
    {
        try
        {
            return (cache.get(key) != null);
        }
        catch (CacheException e)
        {
            throw new AlfrescoRuntimeException("contains failed", e);
        }
    }

    @SuppressWarnings("unchecked")
    public Collection<K> getKeys()
    {
        return cache.getKeys();
    }

    @SuppressWarnings("unchecked")
    public V get(K key)
    {
        try
        {
            Element element = cache.get(key);
            if (element != null)
            {
                return (V) element.getValue();
            }
            else
            {
                return null;
            }
        }
        catch (CacheException e)
        {
            throw new AlfrescoRuntimeException("Failed to get from EhCache: \n" +
                    "   key: " + key);
        }
    }

    public void put(K key, V value)
    {
        Element element = new Element(key, value);
        cache.put(element);
    }

    public void remove(K key)
    {
        cache.remove(key);
    }

    public void clear()
    {
        cache.removeAll();
    }
}
