Application: gvSIG desktop » gvSIG raster

package org.gvsig.raster.cache.buffer.impl.stripecache;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.IOException;

import org.gvsig.raster.cache.buffer.BufferDataSource;

import org.gvsig.raster.cache.buffer.exception.WrongParameterException;

import org.gvsig.raster.cache.buffer.impl.BufferServices;

/**

 * Esta clase representa una p?gina de disco. Una p?gina de disco tendr? un n?mero de

 * p?gina asociado y un servidor de datos de disco por cada banda. 

 * 

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

 */

public class HDDPage {

        private String              timePag    = null;    

        private int                 iPag       = -1;

        private int                 nBands     = -1;

        private BufferDataSource    dataSource = null;

        /**

         * Constructor: crea un objeto dataSource para cada banda. Para todos los datasource de un 

         * mismo HddPage se usa el mismo identificador.

         * @param nPag N?mero de p?gina

         * @param nBands N?mero de bandas del dataset

         */

        public HDDPage(int iPag, int nBands, BufferDataSource dataSource) {

                this.dataSource = dataSource;

                this.iPag = iPag;

                this.nBands = nBands;

                this.timePag = BufferServices.getTemporalPath() + File.separator + Long.toString(System.currentTimeMillis()) + "-" + iPag + "-";

        }

        /**

         * Limpia los trozos de cach? en disco. Despu?s del llamar a este 

         * m?todo no puede volver a usarse esta cach?.

         * @throws IOException 

         */

        public void deletePage() throws IOException {

                for (int i = 0; i < nBands; i++) 

                        dataSource.delete(timePag + i);

        }

        /**

         * Limpia los trozos de cach? en disco de una banda. Despu?s del llamar a este 

         * m?todo no puede volver a usarse esta banda.

         * @throws IOException 

         */

        public void removeBand(int pos) throws IOException {

                dataSource.delete(timePag + pos);

                for (int i = (pos + 1); i < nBands; i++) 

                        dataSource.changeFileName(timePag + i, timePag + (i - 1));

                nBands --;

        }

        /**

         * Adds a new band in the selected position. 

         * @param pos

         * @throws IOException 

         */

        public void addBand(int pos, PageBuffer pb) throws IOException {

                for (int i = (nBands - 1); i >= pos ; i--)

                        dataSource.changeFileName(timePag + i, timePag + (i + 1));

                dataSource.saveBand(pb.getBand(0), timePag + pos);

                nBands ++;

        }

        /**

         * Swaps bands according to positions selected in bandPosition parameter.

         * 

         * @param  bandPosition

         *         New order for the bands in the array. Each position in the array represent the old band

         *         .The number that it contains represent the new position of that band. For instance, an

         *         array with values {1, 0, 2, 3} means that it has four bands and the band number one is swaped

         *         with the band number zero. The bands two and three don't change its position in this example.                           

         * @throws WrongParameterException

         */

         public void swapBands(int[] bandPosition) throws WrongParameterException {

                 for (int i = 0; i < bandPosition.length; i++) 

                         dataSource.changeFileName(timePag + i, timePag + i + "old");

                 for (int i = 0; i < bandPosition.length; i++) 

                         dataSource.changeFileName(timePag + bandPosition[i] + "old", timePag + i);

         }

        /**

         * Loads a page of data from the hard disk. 

         * @param buf Buffer where is loaded

         * @throws InterruptedException

         */

        public void loadPage(PageBuffer buf) throws InterruptedException {

                dataSource.loadPage(buf, timePag);

        }

        /**

         * Salva una p?gina especificada en el par?metro nPag a disco. 

         * Para esto recorre todas las bandas de la p?gina llamando al save de cada una.

         *   

         * @param nPag N?mero de p?gina a salvar

         * @throws IOException

         */

        public void savePage(PageBuffer buf) throws IOException {

                dataSource.savePage(buf, timePag);

        }

        /**

         * Gets the string with the file id

         * @return

         */

        public String getFileID() {

                return timePag;

        }

        /**

         * Sets the string with the file id

         * @return

         */

        public void setFileID(String id) {

                this.timePag = id;

        }

        /**

         * This method creates a new file with a new identifier and copy data. 

         */

        public Object clone() {

                HDDPage clon = new HDDPage(iPag, nBands, dataSource);

                String newID = BufferServices.getTemporalPath() + File.separator + Long.toString(System.currentTimeMillis()) + "-" + iPag + "-";

                clon.setFileID(newID);

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

                        try {

                                File f = new File(timePag + i);

                                if(f.exists() && f.canRead() && f.canWrite())

                                        BufferServices.copyFile(timePag + i, newID + i);

                        } catch (FileNotFoundException e) {

                                e.printStackTrace();

                        } catch (IOException e) {

                                e.printStackTrace();

                        }

                }

                return clon;

        }

}