/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat, Inc. and/or its affiliates or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat, Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* 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 Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.search.filter;
import java.util.Properties;
import org.apache.lucene.search.Filter;
import org.hibernate.search.Environment;
import org.hibernate.search.backend.configuration.ConfigurationParseHelper;
import org.hibernate.search.util.SoftLimitMRUCache;
/**
* Keep the most recently used Filters in the cache
* The cache is at least as big as <code>hibernate.search.filter.cache_strategy.size</code>
* Above this limit, Filters are kept as soft references
*
* @author Emmanuel Bernard
*/
public class MRUFilterCachingStrategy implements FilterCachingStrategy {
private static final int DEFAULT_SIZE = 128;
private SoftLimitMRUCache cache;
private static final String SIZE = Environment.FILTER_CACHING_STRATEGY + ".size";
/**
* Under memory pressure the JVM will release all Soft references,
* so pushing it too high will invalidate all eventually useful other caches.
*/
private static final int HARD_TO_SOFT_RATIO = 15;
public void initialize(Properties properties) {
int size = ConfigurationParseHelper.getIntValue( properties, SIZE, DEFAULT_SIZE );
cache = new SoftLimitMRUCache( size, size * HARD_TO_SOFT_RATIO );
}
public Filter getCachedFilter(FilterKey key) {
return (Filter) cache.get( key );
}
public void addCachedFilter(FilterKey key, Filter filter) {
cache.put( key, filter );
}
}