/**

  * Copyright (C) 2013 Matthias Langer

  *

  * 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 at.ipsquare.commons.hibernate;

 import java.io.Closeable;

 import org.hibernate.Session;

 import org.hibernate.Transaction;

 import at.ipsquare.commons.core.interfaces.ExecutionError;

 import at.ipsquare.commons.core.interfaces.UnitOfWork;

 import at.ipsquare.commons.core.interfaces.UnitOfWorkExecutor;

 /**

  * Wraps our Hibernate repository.

  * 

  * <h4>Notes:</h4>

  * <ul>

  *  <li>Implementations of this interface can be expected to be thread save.</li>

  * </ul>

  * 

  * @author Matthias Langer

  * @since 2.0.0

  */

 public interface HibernateRepository extends UnitOfWorkExecutor, Closeable

 {

     /**

      * Executes the given {@link UnitOfWork} within a single transaction.

      * 

      * <h4>Notes:</h4>

      *  <ul>

      *      <li>If you need more fine grained transaction management, you can do so by manipulating {@link #currentSession()} accordingly.</li>

      *      <li>Implementations of this class can be expected to be thread save; executing multiple units of work concurrently is save.</li>

      *      <li>

      *          It is not an error to execute a {@link UnitOfWork} while another {@link UnitOfWork} is already executing. However note that

      *          when doing so the {@link Session} or the current {@link Transaction} is not modified.

      *      </li>

      *  </ul>

      * 

      * @param work a {@link UnitOfWork} that should be executed.

      * @return the result of the {@link UnitOfWork}.

      * 

      * @throws ExecutionError if {@link UnitOfWork#execute()} throws an exception.

      */

     <T> T executeUnitOfWork(UnitOfWork<T> work);

     /**

      * Returns the currently open session for this thread.

      * 

      * @throws IllegalStateException if no {@link UnitOfWork} is currently executing in this thread.

      */

     Session currentSession();

     /**

      * Closes the repository (all acquired resources are released).

      */

     @Override

     void close();

     /**

      * Returns true if the repository is closed.

      */

     boolean isClosed();

 }