package org.apache.ojb.otm.lock;

 /* Copyright 2003-2005 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.metadata.ClassDescriptor;

 import org.apache.ojb.broker.locking.IsolationLevels;

 import org.apache.ojb.broker.PersistenceBroker;

 import org.apache.ojb.otm.lock.isolation.ReadCommittedIsolation;

 import org.apache.ojb.otm.lock.isolation.ReadUncommittedIsolation;

 import org.apache.ojb.otm.lock.isolation.RepeatableReadIsolation;

 import org.apache.ojb.otm.lock.isolation.SerializableIsolation;

 import org.apache.ojb.otm.lock.isolation.TransactionIsolation;

 /**

  *

  * <javadoc>

  *

  * @author <a href="mailto:rraghuram@hotmail.com">Raghu Rajah</a>

  *

  */

 public class IsolationFactory

 {

     private static final TransactionIsolation READ_UNCOMMITTED_ISOLATION

         = new ReadUncommittedIsolation();

     private static final TransactionIsolation READ_COMMITTED_ISOLATION

         = new ReadCommittedIsolation();

     private static final TransactionIsolation REPEATABLE_READ_ISOLATION

         = new RepeatableReadIsolation();

     private static final TransactionIsolation SERIALIZABLE_ISOLATION

         = new SerializableIsolation();

     /**

      *

      * Fetches the isolation level of given class from its ClassDescriptor.

      *

      */

     public static TransactionIsolation getIsolationLevel (PersistenceBroker pb,

                                                           ObjectLock lock)

     {

         /*

         arminw: use real object class instead of top-level class

         to match isolation level of given class

         */

         // Class clazz = lock.getTargetIdentity().getObjectsTopLevelClass();

         Class clazz = lock.getTargetIdentity().getObjectsRealClass();

         ClassDescriptor classDescriptor = pb.getClassDescriptor(clazz);

         int isolationLevel = classDescriptor.getIsolationLevel();

         TransactionIsolation isolation = null;

         switch (isolationLevel) {

             case IsolationLevels.IL_READ_UNCOMMITTED:

                 isolation = READ_UNCOMMITTED_ISOLATION;

                 break;

             case IsolationLevels.IL_READ_COMMITTED:

                 isolation = READ_COMMITTED_ISOLATION;

                 break;

             case IsolationLevels.IL_REPEATABLE_READ:

                 isolation = REPEATABLE_READ_ISOLATION;

                 break;

             case IsolationLevels.IL_SERIALIZABLE:

                 isolation = SERIALIZABLE_ISOLATION;

                 break;

             default:

                 throw new UnknownIsolationException(

                     "Isolation level " + isolationLevel + " is not supported");

         }

         return isolation;

     }

 }