Application: gvSIG desktop » gvSIG raster

/* gvSIG. Geographic Information System of the Valencian Government

*

* Copyright (C) 2007-2008 Infrastructures and Transports Department

* of the Valencian Government (CIT)

* 

* This program is free software; you can redistribute it and/or

* modify it under the terms of the GNU General Public License

* as published by the Free Software Foundation; either version 2

* of the License, or (at your option) any later version.

* 

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

* GNU General Public License for more details.

* 

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 

* MA  02110-1301, USA.

* 

*/

package org.gvsig.raster.reproject.app.preparelayer;

import org.gvsig.fmap.dal.coverage.RasterLocator;

import org.gvsig.fmap.dal.coverage.exception.ProcessInterruptedException;

import org.gvsig.raster.algorithm.process.IProcessActions;

import org.gvsig.raster.algorithm.process.ProcessException;

import org.gvsig.raster.algorithm.process.DataProcess;

import org.gvsig.raster.util.Queue;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

 * Cola de procesos de ejecuci?n exclusiva. Los procesos de esta lista se ir?n ejecutando

 * por orden de llegada impidiendo que se ejecuten dos al mismo tiempo.

 * 

 * 16/05/2008

 * @author Nacho Brodin nachobrodin@gmail.com

 */

public class ReprojectionQueue extends Thread {

        private Queue                     queue                       = new Queue();

        private DataProcess             executionProcess            = null;

        static private ReprojectionQueue  singleton                   = null;

        private Logger                    logger                      = LoggerFactory.getLogger(ReprojectionQueue.class.toString());

        /**

         * Devuelve una instancia al unico objeto de UniqueProcessQueue que puede existir.

         * @return

         */

        static public ReprojectionQueue getSingleton() {

                if(singleton == null) {

                        singleton = new ReprojectionQueue();

                        synchronized (singleton) {

                                singleton.start();

                        }

                }

                return singleton;

        }

        public void run() {

                //Cuando arranca el thread se duerme porque la cola est? vacia

                synchronized (this) {

                        try {

                                wait();

                        } catch (InterruptedException e) {

                        }

                }

                while(true) {

                        if(queue.size() >= 1) {

                                Object[] obj = (Object[])queue.get();

                                executionProcess = ((DataProcess) obj[0]);

                                if (executionProcess != null) {

                                        executionProcess.showIncrementableWindow();

                                        try {

                                                executionProcess.execute();

                                        } catch (ProcessInterruptedException e) {

                                        } catch (ProcessException e) {

                                                logger.debug(RasterLocator.getManager().getRasterUtils().getTrace(e));

                                        }

                                        executionProcess.getIncrementableTask().processFinalize();

                                        //Despierta el objeto que llam? cuando termina el calculo

                                        //para que pueda recoger los resultados

                                        synchronized (obj[1]) {

                                                obj[1].notify();        

                                        }

                                        //Cuando la cola est? vacia se suspende el hilo.

                                        if(queue.size() <= 0) {

                                                synchronized (this) {

                                                        try {

                                                                this.wait();

                                                        } catch (InterruptedException e) {

                                                        }

                                                }

                                        }

                                }

                        }

                }

        }        

        /**

         * A?ade un proceso a la cola.

         * @param id Identificador del proceso

         * @param process Proceso

         * @throws InterruptedException 

         */

        public synchronized void add(DataProcess process, IProcessActions obj) {

                queue.put(new Object[]{process, obj});

        }

}