/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited

  *

  * Licensed 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.acegisecurity.acl.basic.cache;

 import net.sf.ehcache.CacheException;

 import net.sf.ehcache.Element;

 import net.sf.ehcache.Ehcache;

 import org.acegisecurity.acl.basic.AclObjectIdentity;

 import org.acegisecurity.acl.basic.BasicAclEntry;

 import org.acegisecurity.acl.basic.BasicAclEntryCache;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.springframework.beans.factory.InitializingBean;

 import org.springframework.dao.DataRetrievalFailureException;

 import org.springframework.util.Assert;

 /**

  * Caches <code>BasicAclEntry</code>s using a Spring IoC defined <A

  * HREF="http://ehcache.sourceforge.net">EHCACHE</a>.

  *

  * @author Ben Alex

  * @version $Id: EhCacheBasedAclEntryCache.java 1965 2007-08-27 23:41:59Z luke_t $

  */

 public class EhCacheBasedAclEntryCache implements BasicAclEntryCache, InitializingBean {

     //~ Static fields/initializers =====================================================================================

     private static final Log logger = LogFactory.getLog(EhCacheBasedAclEntryCache.class);

     //~ Instance fields ================================================================================================

     private Ehcache cache;

     //~ Methods ========================================================================================================

     public void afterPropertiesSet() throws Exception {

         Assert.notNull(cache, "cache mandatory");

     }

     public BasicAclEntry[] getEntriesFromCache(AclObjectIdentity aclObjectIdentity) {

         Element element = null;

         try {

             element = cache.get(aclObjectIdentity);

         } catch (CacheException cacheException) {

             throw new DataRetrievalFailureException("Cache failure: " + cacheException.getMessage());

         }

         // Return null if cache element has expired or not found

         if (element == null) {

             if (logger.isDebugEnabled()) {

                 logger.debug("Cache miss: " + aclObjectIdentity);

             }

             return null;

         }

         if (logger.isDebugEnabled()) {

             logger.debug("Cache hit: " + (element != null) + "; object: " + aclObjectIdentity);

         }

         BasicAclEntryHolder holder = (BasicAclEntryHolder) element.getValue();

         return holder.getBasicAclEntries();

     }

     public void putEntriesInCache(BasicAclEntry[] basicAclEntry) {

         BasicAclEntryHolder holder = new BasicAclEntryHolder(basicAclEntry);

         Element element = new Element(basicAclEntry[0].getAclObjectIdentity(), holder);

         if (logger.isDebugEnabled()) {

             logger.debug("Cache put: " + element.getKey());

         }

         cache.put(element);

     }

     public void removeEntriesFromCache(AclObjectIdentity aclObjectIdentity) {

         cache.remove(aclObjectIdentity);

     }

     public Ehcache getCache() {

         return cache;

     }

     public void setCache(Ehcache cache) {

         this.cache = cache;

     }

 }