/*

  * This software is licensed under the Apache License, Version 2.0

  * (the "License") agreement; 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 net.admin4j.dao.xml;

 import java.beans.DefaultPersistenceDelegate;

 import java.beans.XMLDecoder;

 import java.beans.XMLEncoder;

 import java.io.BufferedInputStream;

 import java.io.BufferedOutputStream;

 import java.io.FileInputStream;

 import java.io.FileOutputStream;

 import java.util.Set;

 import net.admin4j.config.Admin4JConfiguration;

 import net.admin4j.dao.TaskTimerDAO;

 import net.admin4j.timer.BasicTaskTimer;

 import net.admin4j.timer.SummaryDataMeasure;

 import net.admin4j.timer.TaskTimer;

 import net.admin4j.util.Admin4jRuntimeException;

 /**

  * DAO implementation for reading/writing performance measurement information.

  * @author D. Ashmore

  * @since 1.0

  */

 public class TaskTimerDAOXml extends BaseDAOXml implements TaskTimerDAO {

     private static final Object SAVE_LOCK = new Object();

     @SuppressWarnings("unchecked")

     public Set<TaskTimer> findAll() {

         Set<TaskTimer> result = null;

         XMLDecoder decoder = null;

         String xmlFileName = Admin4JConfiguration.getPerformanceInformationXmlFileName();

         /*

          * Note: classloader assigning business to work around JDK bug

          * http://bugs.sun.com/view_bug.do?bug_id=6329581

          */

         ClassLoader currentContextLoader = Thread.currentThread().getContextClassLoader();

         try {

             Thread.currentThread().setContextClassLoader(TaskTimer.class.getClassLoader());

             decoder = new XMLDecoder(

                 new BufferedInputStream(

                     new FileInputStream(xmlFileName)));

             decoder.setExceptionListener(new DefaultExceptionListener(xmlFileName));

             result = (Set<TaskTimer>)decoder.readObject();

         }

         catch (Throwable t) {

             throw new Admin4jRuntimeException("Error reading XML Performance Information.", t)

                 .addContextValue("xmlFileName", xmlFileName);

         }

         finally {

             if (decoder != null) decoder.close();

             Thread.currentThread().setContextClassLoader(currentContextLoader);

         }

         return result;

     }

     public void saveAll(Set<TaskTimer> exceptionList) {

         XMLEncoder encoder = null;

         String xmlFileName = Admin4JConfiguration.getPerformanceInformationXmlFileName();

         String tempFileName = xmlFileName + ".temp";

         String previousFileName = derivePreviousFileName( ".previous" );

         boolean encoderClosed = false;

         /*

          * Write to a .temp file

          * Rename configured xml file to .previous

          * Rename new .temp to the configured file name.

          * 

          * Note: classloader assigning business to work around JDK bug

          * http://bugs.sun.com/view_bug.do?bug_id=6329581

          */

         synchronized (SAVE_LOCK) {

             ClassLoader currentContextLoader = Thread.currentThread().getContextClassLoader();

             try {

                 Thread.currentThread().setContextClassLoader(TaskTimer.class.getClassLoader());

                 encoder = new XMLEncoder(

                         new BufferedOutputStream(

                             new FileOutputStream(tempFileName)));

                 encoder.setExceptionListener(new DefaultExceptionListener(xmlFileName));

                 encoder.setPersistenceDelegate(BasicTaskTimer.class, 

                         new DefaultPersistenceDelegate(

                                 new String[]{"label","dataMeasures"}));

                 encoder.setPersistenceDelegate(SummaryDataMeasure.class, 

                         new DefaultPersistenceDelegate(

                                 new String[]{"firstObservationTime"}));

                 encoder.writeObject(exceptionList);

                 encoder.close();

                 encoderClosed = true;

                 versionOutputFile(xmlFileName, tempFileName, previousFileName);

             }

             catch (Throwable t) {

                 if (encoder != null && !encoderClosed) encoder.close();

             }

             finally {

                 Thread.currentThread().setContextClassLoader(currentContextLoader);

             }

         }

     }

 }