| 1 | // Jomic - a viewer for comic book archives. |
| 2 | // Copyright (C) 2004-2011 Thomas Aglassinger |
| 3 | // |
| 4 | // This program is free software: you can redistribute it and/or modify |
| 5 | // it under the terms of the GNU General Public License as published by |
| 6 | // the Free Software Foundation, either version 3 of the License, or |
| 7 | // (at your option) any later version. |
| 8 | // |
| 9 | // This program is distributed in the hope that it will be useful, |
| 10 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | // GNU General Public License for more details. |
| 13 | // |
| 14 | // You should have received a copy of the GNU General Public License |
| 15 | // along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | package net.sf.jomic.tools; |
| 17 | |
| 18 | import java.awt.Color; |
| 19 | import java.awt.Dimension; |
| 20 | import java.awt.image.RenderedImage; |
| 21 | import java.io.File; |
| 22 | import java.io.IOException; |
| 23 | import java.util.HashMap; |
| 24 | import java.util.HashSet; |
| 25 | import java.util.Iterator; |
| 26 | import java.util.Map; |
| 27 | import java.util.Set; |
| 28 | |
| 29 | import javax.imageio.IIOException; |
| 30 | |
| 31 | import org.apache.commons.logging.Log; |
| 32 | import org.apache.commons.logging.LogFactory; |
| 33 | |
| 34 | /** |
| 35 | * Cache to store RenderedImages in memory. When the memory usage exceeds a maximum size, the least |
| 36 | * recent images are removed. Note that the cache holds at least one image, so if this is bigger |
| 37 | * than the maximum size, so is the whole cache. |
| 38 | */ |
| 39 | public class ImageCache implements CacheInfo |
| 40 | { |
| 41 | private static final int BROKEN_IMAGE_HEIGHT = 800; |
| 42 | private static final int BROKEN_IMAGE_WIDTH = 600; |
| 43 | private static final int DEFAULT_BROKEN_BACKGROUND = 0xf0f0f0; |
| 44 | private static final int DEFAULT_BROKEN_FOREGROUND = 0xe04040; |
| 45 | private static final int DEFAULT_BUSY_BACKGROUND = 0xf0f0f0; |
| 46 | private static final int DEFAULT_BUSY_FOREGROUND = 0xd0d0d0; |
| 47 | private static final double ONE_HUNDRED = 100.0; |
| 48 | private Color brokenBackgroundColor; |
| 49 | private Color brokenForegroundColor; |
| 50 | private Color busyBackgroundColor; |
| 51 | private Color busyForegroundColor; |
| 52 | private boolean disposed; |
| 53 | private Map entries; |
| 54 | private ImageTools imageTools; |
| 55 | private Log logger; |
| 56 | private long maxMemorySize; |
| 57 | private long memorySize; |
| 58 | private String name; |
| 59 | private ImageCacheRenderThread renderer; |
| 60 | private Set unrenderableImageFiles; |
| 61 | |
| 62 | public ImageCache(String newName, long newMaxMemorySize) { |
| 63 | assert newName != null; |
| 64 | assert newName.length() > 0; |
| 65 | assert newMaxMemorySize >= 0; |
| 66 | logger = LogFactory.getLog(ImageCache.class); |
| 67 | imageTools = ImageTools.instance(); |
| 68 | name = newName; |
| 69 | entries = new HashMap(); |
| 70 | // TODO: Collect paths of unrenderable images so they won't be attempted to be rendered again. |
| 71 | unrenderableImageFiles = new HashSet(); |
| 72 | maxMemorySize = newMaxMemorySize; |
| 73 | brokenBackgroundColor = new Color(DEFAULT_BROKEN_BACKGROUND); |
| 74 | brokenForegroundColor = new Color(DEFAULT_BROKEN_FOREGROUND); |
| 75 | busyBackgroundColor = new Color(DEFAULT_BUSY_BACKGROUND); |
| 76 | busyForegroundColor = new Color(DEFAULT_BUSY_FOREGROUND); |
| 77 | renderer = new ImageCacheRenderThread(this); |
| 78 | renderer.start(); |
| 79 | } |
| 80 | |
| 81 | public RenderedImage get(File imageFile) |
| 82 | throws IOException { |
| 83 | assert !disposed; |
| 84 | assert imageFile != null; |
| 85 | ImageCacheEntry entry = (ImageCacheEntry) entries.get(imageFile); |
| 86 | |
| 87 | if (entry == null) { |
| 88 | RenderedImage image = obtainImage(imageFile); |
| 89 | |
| 90 | entry = new ImageCacheEntry(imageFile, image); |
| 91 | |
| 92 | long entryMemorySize = entry.getImageSize(); |
| 93 | |
| 94 | memorySize += entryMemorySize; |
| 95 | if (logger.isInfoEnabled()) { |
| 96 | logger.info("memory size increased by " + entryMemorySize + " bytes to " + memorySize); |
| 97 | } |
| 98 | while ((memorySize > maxMemorySize) && (entries.size() > 0)) { |
| 99 | ImageCacheEntry leastRecentlyAccessedEntry = findLeastRecentlyAccessedEntry(); |
| 100 | |
| 101 | logger.info("removing least recently used image to meet memory size requirement"); |
| 102 | remove(leastRecentlyAccessedEntry); |
| 103 | } |
| 104 | entries.put(imageFile, entry); |
| 105 | if (logger.isInfoEnabled()) { |
| 106 | double percentUsed = (ONE_HUNDRED * getUsedSize() / getMaxSize()); |
| 107 | |
| 108 | if (logger.isInfoEnabled()) { |
| 109 | logger.info("entry added: " + imageFile); |
| 110 | logger.info("current cache statistics: " + getEntryCount() + " entries use " |
| 111 | + getUsedSize() + " of " + getMaxSize() + " bytes (" |
| 112 | + StringTools.instance().getPercentText(percentUsed) + "%)"); |
| 113 | } |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | assert entry != null; |
| 118 | entry.updateLastAccessed(); |
| 119 | |
| 120 | RenderedImage result = entry.getImage(); |
| 121 | |
| 122 | assert result != null; |
| 123 | return result; |
| 124 | } |
| 125 | |
| 126 | public RenderedImage get(File imageFile, ImageInCacheListener listener) |
| 127 | throws IOException { |
| 128 | assert !disposed; |
| 129 | assert imageFile != null; |
| 130 | assert listener != null; |
| 131 | RenderedImage result; |
| 132 | |
| 133 | synchronized (entries) { |
| 134 | if (has(imageFile)) { |
| 135 | result = get(imageFile); |
| 136 | } else { |
| 137 | Dimension imageDimension = obtainImageDimension(imageFile); |
| 138 | |
| 139 | result = imageTools.createBusyImage(imageDimension.width, imageDimension.height, |
| 140 | busyBackgroundColor, busyForegroundColor); |
| 141 | |
| 142 | renderer.addTask(imageFile, listener, ImageCacheRenderThread.PRIORITY_SOON); |
| 143 | } |
| 144 | } |
| 145 | return result; |
| 146 | } |
| 147 | |
| 148 | public Dimension getDimension(File imageFile) { |
| 149 | assert !disposed; |
| 150 | Dimension result; |
| 151 | |
| 152 | try { |
| 153 | result = obtainImageDimension(imageFile); |
| 154 | } catch (Exception error) { |
| 155 | result = getDefaultImageDimension(); |
| 156 | logger.warn("cannot get dimension of image " + StringTools.instance().sourced(imageFile) |
| 157 | + ", using default: " + result, error); |
| 158 | } |
| 159 | return result; |
| 160 | } |
| 161 | |
| 162 | public int getEntryCount() { |
| 163 | assert !disposed; |
| 164 | return entries.size(); |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * Get number of bytes the cache may fill up before entries get thrown out. Note that the cache |
| 169 | * will hold at least 1 image, so if this is bigger than the maximum size, the actual size may |
| 170 | * exceed the maximum in this case. |
| 171 | */ |
| 172 | public long getMaxSize() { |
| 173 | assert !disposed; |
| 174 | return maxMemorySize; |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | * Get the approximate number of bytes currently used by all images in the cache. |
| 179 | */ |
| 180 | public long getUsedSize() { |
| 181 | assert !disposed; |
| 182 | return memorySize; |
| 183 | } |
| 184 | |
| 185 | protected Dimension getDefaultImageDimension() { |
| 186 | assert !disposed; |
| 187 | |
| 188 | return new Dimension(BROKEN_IMAGE_WIDTH, BROKEN_IMAGE_HEIGHT); |
| 189 | } |
| 190 | |
| 191 | String getName() { |
| 192 | return name; |
| 193 | } |
| 194 | |
| 195 | /** |
| 196 | * Remove all entries from cache. |
| 197 | */ |
| 198 | public void clear() { |
| 199 | assert !disposed; |
| 200 | synchronized (entries) { |
| 201 | entries.clear(); |
| 202 | memorySize = 0; |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * Create a broken image using the cache's default dimension. |
| 208 | */ |
| 209 | public RenderedImage createBrokenImage() { |
| 210 | assert !disposed; |
| 211 | Dimension brokenImageDimension = getDefaultImageDimension(); |
| 212 | RenderedImage result = imageTools.createBrokenImage( |
| 213 | brokenImageDimension.width, brokenImageDimension.height, |
| 214 | brokenBackgroundColor, brokenForegroundColor); |
| 215 | |
| 216 | return result; |
| 217 | } |
| 218 | |
| 219 | public void dispose() { |
| 220 | assert !disposed; |
| 221 | |
| 222 | if (entries != null) { |
| 223 | if (renderer != null) { |
| 224 | renderer.dispose(); |
| 225 | } |
| 226 | clear(); |
| 227 | } |
| 228 | disposed = true; |
| 229 | } |
| 230 | |
| 231 | /** |
| 232 | * Is the image for <code>imageFile</code> already stored in the cache? |
| 233 | */ |
| 234 | public boolean has(File imageFile) { |
| 235 | assert !disposed; |
| 236 | |
| 237 | assert imageFile != null; |
| 238 | return entries.containsKey(imageFile); |
| 239 | } |
| 240 | |
| 241 | protected RenderedImage obtainImage(File imageFile) |
| 242 | throws IOException { |
| 243 | assert !disposed; |
| 244 | assert imageFile != null; |
| 245 | RenderedImage result; |
| 246 | |
| 247 | try { |
| 248 | result = imageTools.readImage(imageFile); |
| 249 | } catch (IIOException error) { |
| 250 | result = createBrokenImage(); |
| 251 | } |
| 252 | return result; |
| 253 | } |
| 254 | |
| 255 | protected Dimension obtainImageDimension(File imageFile) |
| 256 | throws IOException { |
| 257 | assert !disposed; |
| 258 | assert imageFile != null; |
| 259 | Dimension result; |
| 260 | |
| 261 | synchronized (entries) { |
| 262 | if (has(imageFile)) { |
| 263 | RenderedImage image = get(imageFile); |
| 264 | |
| 265 | result = new Dimension(image.getWidth(), image.getHeight()); |
| 266 | } else { |
| 267 | result = imageTools.getImageDimension(imageFile); |
| 268 | } |
| 269 | } |
| 270 | return result; |
| 271 | } |
| 272 | |
| 273 | private ImageCacheEntry findLeastRecentlyAccessedEntry() { |
| 274 | assert !disposed; |
| 275 | |
| 276 | ImageCacheEntry result; |
| 277 | |
| 278 | synchronized (entries) { |
| 279 | Iterator rider = entries.values().iterator(); |
| 280 | |
| 281 | result = (ImageCacheEntry) rider.next(); |
| 282 | |
| 283 | while (rider.hasNext()) { |
| 284 | ImageCacheEntry nextEntry = (ImageCacheEntry) rider.next(); |
| 285 | long leastRecentlyAccessed = result.getLastAccessed(); |
| 286 | long nextAccessed = nextEntry.getLastAccessed(); |
| 287 | |
| 288 | if (leastRecentlyAccessed > nextAccessed) { |
| 289 | result = nextEntry; |
| 290 | } |
| 291 | } |
| 292 | } |
| 293 | return result; |
| 294 | } |
| 295 | |
| 296 | /** |
| 297 | * Remove entry and update the memory size. |
| 298 | */ |
| 299 | private void remove(ImageCacheEntry entryToRemove) { |
| 300 | assert !disposed; |
| 301 | |
| 302 | synchronized (entries) { |
| 303 | if (logger.isInfoEnabled()) { |
| 304 | logger.info("removing entry: " + entryToRemove.getImageFile()); |
| 305 | } |
| 306 | |
| 307 | long entryMemorySize = entryToRemove.getImageSize(); |
| 308 | Object removedEntry = entries.remove(entryToRemove.getImageFile()); |
| 309 | |
| 310 | assert entryToRemove == removedEntry |
| 311 | : "entryToRemove=" + entryToRemove + ", removedEntry=" + removedEntry; |
| 312 | |
| 313 | entryToRemove.dispose(); |
| 314 | memorySize -= entryMemorySize; |
| 315 | if (logger.isInfoEnabled()) { |
| 316 | logger.info("memory size reduced by " + entryMemorySize + " bytes to " + memorySize); |
| 317 | } |
| 318 | } |
| 319 | } |
| 320 | } |