package org.apache.ojb.odmg;

 /* 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.OJBRuntimeException;

 import org.apache.ojb.broker.util.configuration.ConfigurationException;

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

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

 import org.apache.ojb.odmg.oql.EnhancedOQLQuery;

 import org.odmg.DArray;

 import org.odmg.DBag;

 import org.odmg.DList;

 import org.odmg.DMap;

 import org.odmg.DSet;

 import org.odmg.Database;

 import org.odmg.Implementation;

 import org.odmg.Transaction;

 /**

  * Implementation of the ODMG {@link Implementation} interface for use in

  * managed enviroments.

  *

  * @version $Id: ImplementationJTAImpl.java,v 1.1 2007-08-24 22:17:37 ewestfal Exp $

  */

 public class ImplementationJTAImpl extends ImplementationImpl

 {

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

     protected ImplementationJTAImpl()

     {

         super();

     }

     public Database getDatabase(Object obj)

     {

         beginInternTransaction();

         return this.getCurrentDatabase();

     }

     public Transaction currentTransaction()

     {

         beginInternTransaction();

         /*

         we wrap the intern odmg transaction to avoid unauthorised calls

         since we use proprietary extensions for Transaction interface

         do cast to enhanced interface

         */

         return new NarrowTransaction((TransactionImpl) super.currentTransaction());

     }

     public EnhancedOQLQuery newOQLQuery()

     {

         beginInternTransaction();

         return super.newOQLQuery();

     }

     public DList newDList()

     {

         beginInternTransaction();

         return super.newDList();

     }

     public DBag newDBag()

     {

         beginInternTransaction();

         return super.newDBag();

     }

     public DSet newDSet()

     {

         beginInternTransaction();

         return super.newDSet();

     }

     public DArray newDArray()

     {

         beginInternTransaction();

         return super.newDArray();

     }

     public DMap newDMap()

     {

         beginInternTransaction();

         return super.newDMap();

     }

     /**

      * Here we start a intern odmg-Transaction to hide transaction demarcation

      * This method could be invoked several times within a transaction, but only

      * the first call begin a intern odmg transaction

      */

     private void beginInternTransaction()

     {

         if (log.isDebugEnabled()) log.debug("beginInternTransaction was called");

         J2EETransactionImpl tx = (J2EETransactionImpl) super.currentTransaction();

         if (tx == null) tx = newInternTransaction();

         if (!tx.isOpen())

         {

             // start the transaction

             tx.begin();

             tx.setInExternTransaction(true);

         }

     }

     /**

      * Returns a new intern odmg-transaction for the current database.

      */

     private J2EETransactionImpl newInternTransaction()

     {

         if (log.isDebugEnabled()) log.debug("obtain new intern odmg-transaction");

         J2EETransactionImpl tx = new J2EETransactionImpl(this);

         try

         {

             getConfigurator().configure(tx);

         }

         catch (ConfigurationException e)

         {

             throw new OJBRuntimeException("Cannot create new intern odmg transaction", e);

         }

         return tx;

     }

     /**

      * Not supported in managed-environment.

      */

     public Transaction newTransaction()

     {

         throw new UnsupportedOperationException("Not supported in managed environment");

     }

 }