org.simantics.district.maps/src/org/simantics/maps/eclipse/DiskCachingTileProvider.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.maps.eclipse;
  13
  14 import java.awt.Image;
  15 import java.awt.geom.Rectangle2D;
  16 import java.awt.image.BufferedImage;
  17 import java.awt.image.RenderedImage;
  18 import java.io.File;
  19 import java.io.IOException;
  20 import java.net.URI;
  21 import java.util.concurrent.ForkJoinPool;
  22
  23 import javax.imageio.ImageIO;
  24
  25 import org.eclipse.core.runtime.IPath;
  26 import org.eclipse.core.runtime.Platform;
  27 import org.osgi.framework.Bundle;
  28 import org.simantics.maps.ProvisionException;
  29 import org.simantics.maps.internal.ImageUtil;
  30 import org.simantics.maps.tile.ITileProvider;
  31 import org.simantics.maps.tile.TileKey;
  32 import org.slf4j.Logger;
  33 import org.slf4j.LoggerFactory;
  34
  35 /**
  36  * @author Tuukka Lehtonen
  37  */
  38 public class DiskCachingTileProvider implements ITileProvider {
  39
  40     private static final Logger LOGGER = LoggerFactory.getLogger(DiskCachingTileProvider.class);
  41
  42     private final String CACHED_IMAGE_FORMAT = "png";
  43
  44     ITileProvider provider;
  45
  46     IPath         cachePath;
  47
  48     boolean supportAlpha;
  49
  50     public DiskCachingTileProvider(ITileProvider provider, Boolean supportAlpha) {
  51         this.provider = provider;
  52         this.supportAlpha = supportAlpha;
  53         initCache();
  54     }
  55
  56     @Override
  57     public URI getSource() {
  58         return provider.getSource();
  59     }
  60
  61     @Override
  62     public Rectangle2D getExtent() {
  63         return provider.getExtent();
  64     }
  65
  66     private void initCache() {
  67         Bundle b = Platform.getBundle("org.simantics.maps");
  68         if (b == null)
  69             return;
  70         IPath statePath = Platform.getStateLocation(b);
  71         URI source = provider.getSource();
  72         IPath cache = statePath.append("cache").append(source.getScheme()).append(source.getHost());
  73
  74         // Create the cache directory if it doesn't exist.
  75         File f = cache.toFile();
  76         if (!f.exists()) {
  77             f.mkdirs();
  78         } else if (!f.isDirectory()) {
  79             LOGGER.error("Tile cache directory " + f.toString() + " already exists as a file, cannot use it as a cache directory", new Exception());
  80             return;
  81         }
  82
  83         this.cachePath = cache;
  84 //        System.out.println("MAP DATA CACHE: " + cachePath);
  85
  86 //        Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName(CACHED_IMAGE_FORMAT);
  87 //        writer = writers.next();
  88 //        Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName(CACHED_IMAGE_FORMAT);
  89 //        reader = readers.next();
  90     }
  91
  92     private IPath toTileCachePath(TileKey key) {
  93         return cachePath.append(key.getLevel() + "." + key.getX() + "." + key.getY());
  94     }
  95
  96     private Image lookupFromDisk(TileKey key) {
  97         if (cachePath == null)
  98             return null;
  99
 100         IPath cachePath = toTileCachePath(key).addFileExtension(CACHED_IMAGE_FORMAT);
 101         File f = cachePath.toFile();
 102         if (f.exists()) {
 103             try {
 104                 BufferedImage img = ImageIO.read(f);
 105                 if (img != null) {
 106                     //System.out.println("[" + provider + "] Disk cache hit: " + key);
 107                     //System.out.println("[" + provider + "]     image:   " + img);
 108                     // Need to make sure that the type of the loaded image is
 109                     // something that can be rendered in an accelerated fashion.
 110                     return ImageUtil.toScreenCompatibleImage(img);
 111                 }
 112             } catch (IOException e) {
 113                 LOGGER.warn("Failed to load cached tile from {}", f.toString(), e);
 114             } finally {
 115             }
 116             // Data is most likely corrupted, just destroy it.
 117             f.delete();
 118         }
 119 //        System.out.println("Disk cache miss: " + key);
 120         return null;
 121     }
 122
 123     private void cacheToDisk(TileKey key, Image img) {
 124         if (cachePath == null)
 125             return;
 126
 127         if (!(img instanceof RenderedImage))
 128             return;
 129
 130         IPath cachePath = toTileCachePath(key).addFileExtension(CACHED_IMAGE_FORMAT);
 131         File f = cachePath.toFile();
 132         try {
 133             if (ImageIO.write((RenderedImage) img, CACHED_IMAGE_FORMAT, f)) {
 134                 //System.out.println("[" + provider + "] Disk cache write: " + key);
 135             }
 136         } catch (IOException e) {
 137             // Caching failed, be silent about it.
 138         }
 139     }
 140
 141     @Override
 142     public Image get(TileKey key) throws ProvisionException {
 143         Image img = lookupFromDisk(key);
 144         if (img == null) {
 145             img = provider.get(key);
 146             final Image image = img;
 147             if (cachePath != null) {
 148                 // Write image to disk in the background
 149                 ForkJoinPool.commonPool().submit(() -> cacheToDisk(key, image));
 150             }
 151         }
 152         return img;
 153     }
 154
 155     @Override
 156     public String toString() {
 157         return getClass().getSimpleName() + " [" + provider.toString() + "]";
 158     }
 159
 160 }