RELEASE_2_1_13/src/blocks/woody/java/org/apache/cocoon/woody/DefaultCacheManager.java

/*
 * 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.
 */
package org.apache.cocoon.woody;

import java.io.IOException;

import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.component.Component;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.commons.collections.FastHashMap;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceValidity;

/**
 * Component implementing the {@link CacheManager} role.
 * 
 * @version $Id$
 */
public class DefaultCacheManager 
  extends AbstractLogEnabled 
  implements CacheManager, ThreadSafe, Serviceable, Disposable, Configurable, Component {
      
    protected ServiceManager manager;
    protected Configuration configuration;
    protected FastHashMap cache = new FastHashMap();

    public void service(ServiceManager serviceManager) throws ServiceException {
        this.manager = serviceManager;
    }

    /**
     * Configurable
     */
    public void configure(Configuration configuration) throws ConfigurationException {
        this.configuration = configuration;
    }

    public Object get(Source source, String prefix) {
        String key = prefix + source.getURI();
        SourceValidity newValidity = source.getValidity();

        if (newValidity == null) {
            cache.remove(key);
            return null;
        }

        Object[] objectAndValidity = (Object[])cache.get(key);
        if (objectAndValidity == null)
            return null;

        SourceValidity storedValidity = (SourceValidity)objectAndValidity[1];
        int valid = storedValidity.isValid();
        boolean isValid;
        if (valid == 0) {
            valid = storedValidity.isValid(newValidity);
            isValid = (valid == 1);
        } else {
            isValid = (valid == 1);
        }

        if (!isValid) {
            cache.remove(key);
            return null;
        }

        return objectAndValidity[0];
    }

    public void set(Object object, Source source, String prefix) throws IOException {
        String key = prefix + source.getURI();
        SourceValidity validity = source.getValidity();
        if (validity != null) {
            Object[] objectAndValidity = {object,  validity};
            cache.put(key, objectAndValidity);
        }
    }

    /**
     * Disposable
     */
    public void dispose() {
        this.manager = null;
        this.cache = null;
    }
}