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.layer;

import java.io.File;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.util.ArrayList;

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

import org.gvsig.raster.cache.tile.disk.ITileFileSystemStrategy;

import org.gvsig.raster.cache.tile.exception.TileGettingException;

import org.gvsig.raster.cache.tile.impl.TileCacheImpl;

import org.gvsig.raster.cache.tile.impl.TileImpl;

import org.gvsig.raster.cache.tile.impl.memory.LRUTileCache;

import org.gvsig.raster.cache.tile.impl.pool.ThreadPool;

import org.gvsig.raster.cache.tile.layer.TiledLayer;

import org.gvsig.raster.cache.tile.provider.CacheStruct;

import org.gvsig.raster.cache.tile.provider.TileListener;

import org.gvsig.raster.cache.tile.provider.TileServer;

/**

 * Main implementation for the tile cache

 *

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

 */

public class TiledLayerImpl implements TiledLayer {

        private TileServer                  provider          = null;

        private TileCacheImpl               tileCache         = null;

        private String                      basePath          = null;

        private String                      pathToDirLayer    = null;

        private String                      idLayer           = null;

        //private LRUTileCache                memoryCache = null;

        private ThreadPool                  pool              = null;

        private ITileFileSystemStrategy     strategy          = null;

        public TiledLayerImpl(TileCacheImpl tileCache, 

                        TileServer provider, 

                        ITileFileSystemStrategy strategy, 

                        LRUTileCache memCache) {

                this.tileCache = tileCache;

                this.provider = provider;

                this.basePath = tileCache.getBaseDirectory();

                //this.memoryCache = memCache;

                this.strategy = strategy;

        }

        public ThreadPool getThreadPool() {

                if(pool == null)

                        pool = new ThreadPool(false);

                return pool;

        }

        /**

         * Updates the string with the base directory

         * @param dir

         */

        public void updateBaseDirectory(String dir) {

                this.basePath = dir;

                this.pathToDirLayer = null;

        }

        public Tile getTile(Tile tile) throws TileGettingException {

                assignPathTile(tile);

                //Busca en memoria

                /*if(memoryCache != null) {

                        buf = memoryCache.get(tile.getId());

                        if(buf != null)

                                return buf;

                }*/

                //Busca en disco

                provider.getDownloader().readTileFromDisk(tile);

                if(tile.dataIsLoaded()) {

                        if(!tile.isCorrupt())

                                return tile;

                        return 

                                null;

                }

                //Lo obtiene y lo carga desde disco

                provider.getDownloader().downloadTile(tile);

                tileCache.updateSize(tile.getFile().length());

                tileCache.saveSize();

                if(!tile.isCorrupt())

                        return tile;

                return 

                        null;

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.cache.tile.layer.TiledLayer#getTiles(java.util.ArrayList, org.gvsig.raster.cache.tile.provider.TileListener)

         */

        public void getTiles(ArrayList<Tile> tiles, TileListener listener) throws TileGettingException {

                org.gvsig.raster.cache.tile.impl.pool.TilePipe pipe = new org.gvsig.raster.cache.tile.impl.pool.TilePipe();

                //If a tile is in memory or in disk then this will be returned 

                //else this will be gotten from the provider

                int nTilesToDownload = 0;

                for (int i = 0; i < tiles.size(); i++) {

                        Tile tile = tiles.get(i);

                        assignPathTile(tile);

                        /*if(memoryCache != null) { //Busca en memoria

                                buf = memoryCache.get(tile.getId());

                                if(buf != null) {

                                        tile.setData(new Object[]{buf});

                                        listener.tileReady(tile);

                                        continue;

                                }

                        }*/

                        provider.getDownloader().readTileFromDisk(tile);

                        if(tile.dataIsLoaded()) {

                                listener.tileReady(tile);

                                continue;

                        }

                        //Lo obtiene desde el proveedor

                        ((TileImpl)tile).setSharedPipe(pipe);

                        ((TileImpl)tile).setDownloader(provider.getDownloader());

                        getThreadPool().addTask(tile);

                        nTilesToDownload ++;

                }

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

                        Tile tile = pipe.getTile();

                        tileCache.updateSize(tile.getFile().length());

                        listener.tileReady(tile);

                }

                tileCache.saveSize();

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.cache.tile.layer.TiledLayer#getBaseLayerDirectory()

         */

        public String getBaseLayerDirectory() {

                CacheStruct struct = provider.getStruct();

                int maxLevel = struct.getNumberOfLevels() - 1;

                if(pathToDirLayer == null) {

                        try {

                                MessageDigest md = java.security.MessageDigest.getInstance("MD5");

                                md.update(new String(struct.getServerURL() + 

                                                struct.getLayerName() + 

                                                struct.getFileSuffix() +

                                                struct.getWorldWidthOfTileMatrixByLevel(maxLevel) + 

                                                struct.getWorldHeightOfTileMatrixByLevel(maxLevel) + 

                                                struct.getTileSizeByLevel(maxLevel)[0] +

                                                struct.getTileSizeByLevel(maxLevel)[1] +

                                                struct.getNumberOfLevels() + 

                                                struct.getEPSG() + 

                                                struct.getFileSize()).getBytes());

                                idLayer = convertToHex(md.digest());

                        } catch (NoSuchAlgorithmException e) {

                                idLayer = new String(struct.getServerURL() + 

                                                struct.getLayerName() +

                                                struct.getFileSuffix() +

                                                struct.getWorldWidthOfTileMatrixByLevel(maxLevel) + 

                                                struct.getWorldHeightOfTileMatrixByLevel(maxLevel) + 

                                                struct.getTileSizeByLevel(maxLevel)[0] +

                                                struct.getTileSizeByLevel(maxLevel)[1] +

                                                struct.getNumberOfLevels() + 

                                                struct.getEPSG() +

                                                struct.getFileSize());

                        }

                        int begin = struct.getLayerName().lastIndexOf(File.separator) + 1;

                        int end = struct.getLayerName().lastIndexOf(".");

                        end = end < 0 ? struct.getLayerName().length() : end;

                        String name = struct.getLayerName().substring(begin, end);

                        idLayer = idLayer + "-" + name;

                        pathToDirLayer = basePath + File.separator + idLayer;

                }

                return pathToDirLayer;

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.cache.tile.layer.TiledLayer#getID()

         */

        public String getID() {

                if(idLayer == null)

                        getBaseLayerDirectory();

                return idLayer;

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.cache.tile.layer.TiledLayer#delete()

         */

        public long delete() {

                File f = new File(getBaseLayerDirectory());

                if(f.exists() && f.isDirectory()) {

                        return deleteDirectory(f);

                }

                return 0;

        }

        /**

         * Deletes a directory removing first files inside.

         * @param f

         */

        private long deleteDirectory(File f) {

                long size = 0;

                File[] files = f.listFiles();

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

                        if (files[i].isDirectory()) {

                                size += deleteDirectory(files[i]);

                        } else {

                                size += files[i].length();

                        }

                        files[i].delete();

                }

                return size;

        }

        /**

         * Assigns the path to a tile

         * @param tile

         * @return

         */

        public String assignPathTile(Tile tile) {

                String file = getBaseLayerDirectory() + 

                                          File.separator + 

                                          strategy.getRelativeToLayerDirTilePath(tile.getRow(), 

                                                          tile.getCol(), 

                                                          tile.getLevel(),

                                                          tile.getVariable(),

                                                          tile.getZ(),

                                                          tile.getTimeInstant()

                                                          ) +

                      "." + provider.getFileSuffix();

                String path = file.substring(0, file.lastIndexOf(File.separator));

                File f = new File(path);

                if(!f.exists())

                        f.mkdirs();

                tile.setFile(new File(file));

                return file;

        }

        /**

         * Converts an array of bytes to hexadecimal string

         * @param data

         * @return

         */

        private String convertToHex(byte[] data) { 

        StringBuffer buf = new StringBuffer();

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

            int halfbyte = (data[i] >>> 4) & 0x0F;

            int two_halfs = 0;

            do { 

                if ((0 <= halfbyte) && (halfbyte <= 9)) 

                    buf.append((char) ('0' + halfbyte));

                else 

                    buf.append((char) ('a' + (halfbyte - 10)));

                halfbyte = data[i] & 0x0F;

            } while(two_halfs++ < 1);

        } 

        return buf.toString();

    }

}