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.cache.tile.impl.pool;

import java.util.LinkedList;

import java.util.Queue;

import org.gvsig.raster.cache.tile.Tile;

import org.gvsig.raster.cache.tile.pool.AtomicTask;

import org.gvsig.raster.cache.tile.pool.TilePipe;

/**

 * This class manages transactions between the producer and the consumer. The

 * producer download tiles from a server and the consumer is a tile provider

 * which will return downloaded tiles.

 *

 * @author Nacho Brodin (nachobrodin@gmail.com)

 */

public class TilePipeImpl implements TilePipe {

        private boolean              isEmpty        = true;

        private Queue<AtomicTask>    buffer         = new LinkedList<AtomicTask>();

        private boolean              debug          = false;

        public TilePipeImpl() {

                this.debug = false;

        }

        public TilePipeImpl(boolean debug) {

                this.debug = debug;

        }

        /**

         * Sets a tile in the pipe

         * @param tile

         */

        public synchronized void setAtomicTask(AtomicTask task) {

                if(task != null)

                        buffer.add(task);

                isEmpty = false;

                if(debug)

                        System.err.println("Setting tile " + ((Tile)task).getCol() + " " + ((Tile)task).getRow());

                notify();

        }

        /**

         * Gets a tile from the pipe

         * @return

         */

        public synchronized AtomicTask getAtomicTask() {

                if(debug)

                        System.out.println("0-Getting tile ");

                while( isEmpty == true ) {

                        try {

                                wait();

                        } catch( InterruptedException e ) {

                        }

                }

                AtomicTask task = buffer.poll() ;

                if(debug)

                        System.out.println("1-Getting tile " + ((Tile)task).getCol() + " " + ((Tile)task).getRow());

                if( getSize() == 0 )

                        isEmpty = true;

                return task;

        }

        /**

         * Returns the number of elements in the queue

         * @return

         */

        public synchronized int getSize() {

                return buffer.size();

        }

}