| gvSIG desktop 1

/*

 * Created on 13-jun-2007

 *

 * gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

/* CVS MESSAGES:

*

* $Id: PersistentRTreeJsi.java 12380 2007-06-27 20:17:30Z azabala $

* $Log$

* Revision 1.1  2007-06-27 20:17:30  azabala

* new spatial index (rix)

*

*

*/

package org.gvsig.fmap.data.index.spatial.jsi;

import java.awt.geom.Point2D;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.RandomAccessFile;

import java.nio.ByteOrder;

import java.nio.MappedByteBuffer;

import java.nio.channels.FileChannel;

import java.util.Iterator;

import java.util.LinkedHashMap;

import java.util.List;

import java.util.Properties;

import javax.imageio.stream.FileImageOutputStream;

import org.gvsig.fmap.data.index.IndexException;

import org.gvsig.fmap.data.index.spatial.PersistentSpatialIndex;

import org.gvsig.fmap.geom.primitive.Envelope;

import com.infomatiq.jsi.Rectangle;

import com.infomatiq.jsi.rtree.RTree;

/**

 * Persistent spatial index which can resolve nearest neighbour queries.

 * <br>

 * 

 * To use:

 * 

 * PersistentRTreeJsi sptidx = new PersistentRtreeJsi("/home/kk");

 * if(sptidx.exists())

 *  sptidx.load();

 *  

 *  

 *  sptidx.add(rect, int);

 *  ...

 *  sptidx.add(rect2,int2);

 *  sptidx.flush();

 * 

 * @author azabala

 *

 */

public class PersistentRTreeJsi extends RTreeJsi implements PersistentSpatialIndex {

        /**

         * Spatial index in memory

         */

        private RTree rtree;

        /**

         * Spatial index file

         */

        private File rtreeFile;

        private boolean hasChange = false;

        /**

         * Spatial index file extension

         */

        final String rExt = ".rix";

        private LinkedHashMap  rectangles;

        /**

         * Constructor

         * @param file path of the spatial index file

         * @throws IndexException 

         */

        public PersistentRTreeJsi(String file, boolean overwrite) throws IndexException {

                rtree = new RTree();

                Properties props = new Properties();

                rtree.init(props);

                rtreeFile = new File(file + rExt);

                rectangles = new LinkedHashMap();

                if(! overwrite)

                        load();

        }

        public void flush(File f) throws IndexException {

                try {

                        if(! hasChange)

                                return;

                        RandomAccessFile file = new RandomAccessFile(f,

                                                                                                                        "rw");

                        FileImageOutputStream output = new FileImageOutputStream(file);

                        output.setByteOrder(ByteOrder.LITTLE_ENDIAN);

                        int numShapes = rtree.size();

                        output.writeInt(numShapes);

                        Iterator iterator = rtree.iterator();

                        int count = 0;

                        while(iterator.hasNext()){

                                Integer  idx = (Integer) iterator.next();

                                Rectangle nr = (Rectangle) rectangles.get(idx);

                                float xmin = nr.min[0];

                                float ymin = nr.min[1];

                                float xmax = nr.max[0];

                                float ymax = nr.max[1];

                                output.writeFloat(xmin);

                                output.writeFloat(ymin);

                                output.writeFloat(xmax);

                                output.writeFloat(ymax);

                                output.writeInt(idx.intValue());

                                count++;

                        }

                        output.flush();

                        output.close();

                        file.close();

                        hasChange = false;

                } catch (FileNotFoundException e) {

                        throw new IndexException(e);

                } catch (IOException e) {

                        throw new IndexException(e);

                }

        }

        public void flush() throws IndexException {

                flush(rtreeFile);

        }

        public boolean exists() {

                return rtreeFile.exists();

        }

        public void load(File f) throws IndexException {

                if (f == null) throw new IllegalArgumentException("File f cannot be null");

                try {

                        if(! f.exists()){

                                return;

                        }

                        RandomAccessFile file = new RandomAccessFile(f, "r");

                        FileChannel channel = file.getChannel();

                        MappedByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());

                        buf.order(ByteOrder.LITTLE_ENDIAN);

                        int numShapes = buf.getInt();

                        for(int i = 0; i < numShapes; i++){

                                float xmin, ymin, xmax, ymax;

                                int shapeIndex;

                                xmin = buf.getFloat();

                                ymin = buf.getFloat();

                                xmax = buf.getFloat();

                                ymax = buf.getFloat();

                                shapeIndex = buf.getInt();

                                Rectangle jsiRect = new Rectangle(xmin, ymin, xmax, ymax);

                                rtree.add(jsiRect, shapeIndex);

                        }

                }catch(Exception e){

                        throw new IndexException(e);

                }                

        }

        public void load() throws IndexException {

                load(rtreeFile);

        }

        public void close() {

                rectangles.clear();

                rectangles = null;

        }

        public void insert(Envelope env, int index) {

                super.insert(env, index);

                rectangles.put(new Integer(index), toJsiRect(env));

                hasChange = true;

        }

        public void delete(Envelope env, int index) {

                super.delete(env, index);

                rectangles.remove(new Integer(index));

                hasChange = true;

        }

        public List findNNearest(int numberOfNearest, Point2D point){

                com.infomatiq.jsi.Point jsiPoint =

                        new com.infomatiq.jsi.Point((float)point.getX(),(float)point.getY());

                return (List) rtree.nearest(jsiPoint, numberOfNearest);

        }

        public File getFile() {

                return this.rtreeFile;

        }

}