package org.apache.ojb.broker.cache;

 /* Copyright 2002-2005 The Apache Software Foundation

  *

  * 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.

  */

 import org.apache.ojb.broker.PersistenceBroker;

 import org.apache.ojb.broker.util.logging.Logger;

 import org.apache.ojb.broker.util.logging.LoggerFactory;

 /**

  * Factory for {@link ObjectCache} implementation classes.

  * Each given {@link org.apache.ojb.broker.PersistenceBroker}

  * was associated with its own <code>ObjectCache</code> instance

  * and vice versa.

  *

  * @author <a href="mailto:thma@apache.org">Thomas Mahler<a>

  * @version $Id: ObjectCacheFactory.java,v 1.1 2007-08-24 22:17:29 ewestfal Exp $

  */

 public class ObjectCacheFactory

 {

     private Logger log = LoggerFactory.getLogger(ObjectCacheFactory.class);

     private static ObjectCacheFactory singleton = new ObjectCacheFactory();

     /**

      * Get the ObjectCacheFactory instance.

      */

     public static ObjectCacheFactory getInstance()

     {

         return singleton;

     }

     private ObjectCacheFactory()

     {

     }

     /**

      * Creates a new {@link ObjectCacheInternal} instance. Each <tt>ObjectCache</tt>

      * implementation was wrapped by a {@link CacheDistributor} and the distributor

      * was wrapped by {@link MaterializationCache}.

      *

      * @param broker The PB instance to associate with the cache instance

      */

     public MaterializationCache createObjectCache(PersistenceBroker broker)

     {

         CacheDistributor cache = null;

         try

         {

             log.info("Start creating new ObjectCache instance");

             /*

             1.

             if default cache was not found,

             create an new instance of the default cache specified in the

             configuration.

             2.

             Then instantiate AllocatorObjectCache to handle

             per connection/ per class caching instances.

             3.

             To support intern operations we wrap ObjectCache with an

             InternalObjectCache implementation

             */

             cache = new CacheDistributor(broker);

             log.info("Instantiate new " + cache.getClass().getName() + " for PB instance " + broker);

         }

         catch(Exception e)

         {

             log.error("Error while initiation, please check your configuration" +

                     " files and the used implementation class", e);

         }

         log.info("New ObjectCache instance was created");

         return new MaterializationCache(cache);

     }

 }