package org.apache.velocity.runtime.resource;
/*
* 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.
*/
import java.util.Collections;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;
import java.util.Iterator;
import org.apache.commons.collections.map.LRUMap;
import org.apache.velocity.runtime.RuntimeConstants;
import org.apache.velocity.runtime.RuntimeServices;
import org.apache.velocity.util.MapFactory;
/**
* Default implementation of the resource cache for the default
* ResourceManager. The cache uses a <i>least recently used</i> (LRU)
* algorithm, with a maximum size specified via the
* <code>resource.manager.cache.size</code> property (idenfied by the
* {@link
* org.apache.velocity.runtime.RuntimeConstants#RESOURCE_MANAGER_DEFAULTCACHE_SIZE}
* constant). This property get be set to <code>0</code> or less for
* a greedy, unbounded cache (the behavior from pre-v1.5).
*
* @author <a href="mailto:[email protected]">Geir Magnusson Jr.</a>
* @author <a href="mailto:[email protected]">Daniel Rall</a>
* @version $Id: ResourceCacheImpl.java 685385 2008-08-12 23:59:06Z nbubna $
*/
public class ResourceCacheImpl implements ResourceCache
{
/**
* Cache storage, assumed to be thread-safe.
*/
protected Map cache = MapFactory.create(512, 0.5f, 30, false);
/**
* Runtime services, generally initialized by the
* <code>initialize()</code> method.
*/
protected RuntimeServices rsvc = null;
/**
* @see org.apache.velocity.runtime.resource.ResourceCache#initialize(org.apache.velocity.runtime.RuntimeServices)
*/
public void initialize( RuntimeServices rs )
{
rsvc = rs;
int maxSize =
rsvc.getInt(RuntimeConstants.RESOURCE_MANAGER_DEFAULTCACHE_SIZE, 89);
if (maxSize > 0)
{
// Create a whole new Map here to avoid hanging on to a
// handle to the unsynch'd LRUMap for our lifetime.
Map lruCache = Collections.synchronizedMap(new LRUMap(maxSize));
lruCache.putAll(cache);
cache = lruCache;
}
rsvc.getLog().debug("ResourceCache: initialized ("+this.getClass()+") with "+
cache.getClass()+" cache map.");
}
/**
* @see org.apache.velocity.runtime.resource.ResourceCache#get(java.lang.Object)
*/
public Resource get( Object key )
{
return (Resource) cache.get( key );
}
/**
* @see org.apache.velocity.runtime.resource.ResourceCache#put(java.lang.Object, org.apache.velocity.runtime.resource.Resource)
*/
public Resource put( Object key, Resource value )
{
return (Resource) cache.put( key, value );
}
/**
* @see org.apache.velocity.runtime.resource.ResourceCache#remove(java.lang.Object)
*/
public Resource remove( Object key )
{
return (Resource) cache.remove( key );
}
/**
* @see org.apache.velocity.runtime.resource.ResourceCache#enumerateKeys()
*/
public Iterator enumerateKeys()
{
return cache.keySet().iterator();
}
}
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