#2 Memory cache added

pl.edu.agh.cast.map/plugin.xml

@@ -13,5 +13,11 @@
          </property>
       </product>
    </extension>
+   <extension
+         point="org.eclipse.core.runtime.preferences">
+      <initializer
+            class="pl.edu.agh.cast.map.config.PreferencesMapConfigurator$DefualtValuesInitializer">
+      </initializer>
+   </extension>
 
 </plugin>

pl.edu.agh.cast.map/src/main/java/pl/edu/agh/cast/map/cache/IMapCache.java

@@ -0,0 +1,47 @@
+package pl.edu.agh.cast.map.cache;
+
+import org.eclipse.swt.graphics.ImageData;
+
+import pl.edu.agh.cast.common.IDisposable;
+
+/**
+ * Map cache is one of the elements in map tile sources chain. Map cache has been distinguished from
+ * {@link pl.edu.agh.cast.map.editor.provider.IMapProvider} due to the fact that cache is operating on already loaded tiles (In fact
+ * definition of 'already loaded tiles' can vary in different {@link IMapCache} implementation) to enhance performance of obtaining tiles
+ * greatly.
+ * 
+ */
+public interface IMapCache extends IDisposable {
+
+    /**
+     * Return tile described by 3 parameters - map's zoom level, tile's column number and tile's row number.<br/>
+     * Tiles can be requested synchronously in UI Thread or asynchronously from other thread, so <b>synchronization if needed should be
+     * considered</b>.
+     * 
+     * @param zoom
+     *            Map's zoom level.
+     * @param column
+     *            Tile's column number.
+     * @param row
+     *            Tile's row number.
+     * 
+     * @return Image of requested tile or <code>null</code> otherwise.
+     */
+    ImageData getTile(int zoom, int column, int row);
+
+    /**
+     * Saves tile (described by 3 parameters - map's zoom level, tile's column number and tile's row number) in cache. Tiles can be provided
+     * synchronously in UI Thread or asynchronously from other thread, so <b>synchronization if needed should be considered</b>.
+     * 
+     * @param zoom
+     *            Map's zoom level.
+     * @param column
+     *            Tile's column number.
+     * @param row
+     *            Tile's row number.
+     * @param tile
+     *            Image of tile.
+     */
+    void saveTile(int zoom, int column, int row, ImageData tile);
+
+}

pl.edu.agh.cast.map/src/main/java/pl/edu/agh/cast/map/cache/MemoryMapCache.java

@@ -0,0 +1,161 @@
+package pl.edu.agh.cast.map.cache;
+
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.apache.log4j.Logger;
+import org.eclipse.swt.graphics.ImageData;
+
+import pl.edu.agh.cast.map.config.IMapConfigurationProvider;
+
+/**
+ * Caches map's tiles in memory.
+ * 
+ */
+public class MemoryMapCache implements IMapCache {
+
+	/**
+	 * Logger.
+	 */
+	private static Logger log = Logger.getLogger(MemoryMapCache.class);
+
+	/**
+	 * Limit of operational memory (In megabytes).
+	 */
+	private int memoryLimit;
+
+	/**
+	 * Size of allocated memory (in bytes).
+	 */
+	private long allocatedMemory;
+
+	/**
+	 * Map of cached tiles.
+	 */
+	private Map<String, ImageData> cachedTiles = Collections
+			.synchronizedMap(new LinkedHashMap<String, ImageData>());
+
+	/**
+	 * Constructor.
+	 * 
+	 * @param memoryLimit
+	 *            Limit of memory that can be used for tiles storing (in
+	 *            megabytes).
+	 */
+	public MemoryMapCache(int memoryLimit) {
+		this.memoryLimit = memoryLimit;
+		allocatedMemory = 0;
+	}
+
+	// BEGIN API Methods
+
+	/**
+	 * Creates instance of {@link MemoryMapCache}. Appropriate memory cache's
+	 * configuration is obtained from given {@link IMapConfigurationProvider}.
+	 * If memory cache is disabled in application's setting than
+	 * <code>null</code> will be returned.
+	 * 
+	 * @return Instance of {@link MemoryMapCache} or <code>null</code> is memory
+	 *         cache is disabled
+	 */
+	public static MemoryMapCache createMemoryMapCache(
+			IMapConfigurationProvider config) {
+		MemoryMapCache result = null;
+
+		if (config.memoryCacheEnabled()) {
+			result = new MemoryMapCache(config.memoryCacheLimit());
+		}
+
+		return result;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 * 
+	 * @see pl.edu.agh.cast.map.editor.cache.IMapCache#getTile(int, int, int)
+	 */
+	@Override
+	public ImageData getTile(int zoom, int column, int row) {
+		return cachedTiles.get(getKey(zoom, column, row));
+	}
+
+	/**
+	 * {@inheritDoc}
+	 * 
+	 * @see pl.edu.agh.cast.map.editor.cache.IMapCache#saveTile(int, int, int,
+	 *      org.eclipse.swt.graphics.ImageData)
+	 */
+	@Override
+	public void saveTile(int zoom, int column, int row, ImageData tile) {
+		String key = getKey(zoom, column, row);
+		ImageData old = cachedTiles.put(key, tile);
+		if (old != null) {
+			if (log.isDebugEnabled()) {
+				log.debug(String.format(
+						"Tile under key %s has been overriden.", key)); //$NON-NLS-1$
+			}
+		}
+
+		long newSize = sizeOfImage(tile);
+		long oldSize = sizeOfImage(old);
+		allocatedMemory += newSize - oldSize;
+
+		while ((allocatedMemory / 1048576.0) > memoryLimit) {
+			synchronized (cachedTiles) {
+				Iterator<String> iterator = cachedTiles.keySet().iterator();
+				if (iterator.hasNext()) {
+					allocatedMemory -= sizeOfImage(cachedTiles.get(iterator
+							.next()));
+					iterator.remove();
+				}
+			}
+		}
+	}
+
+	/**
+	 * {@inheritDoc}
+	 * 
+	 * @see pl.edu.agh.cast.common.IDisposable#dispose()
+	 */
+	@Override
+	public void dispose() {
+		cachedTiles.clear();
+		allocatedMemory = 0;
+	}
+
+	// END API Methods
+
+	/**
+	 * Returns key for specified attributes.
+	 * 
+	 * @param zoom
+	 *            Tile zoom level.
+	 * @param column
+	 *            Tile column.
+	 * @param row
+	 *            Tile row.
+	 * @return Key for specified attributes.
+	 */
+	private String getKey(int zoom, int column, int row) {
+		String separator = "/"; //$NON-NLS-1$
+		return zoom + separator + column + separator + row;
+	}
+
+	/**
+	 * Returns size of image in memory.
+	 * 
+	 * @param image
+	 *            Image to investigate.
+	 * @return Size of image in memory.
+	 */
+	private long sizeOfImage(ImageData image) {
+		if (image == null) {
+			return 0;
+		}
+
+		return image.width * image.height * (image.depth / 8);
+	}
+
+}

pl.edu.agh.cast.map/src/main/java/pl/edu/agh/cast/map/config/IMapConfigurationProvider.java

@@ -0,0 +1,21 @@
+package pl.edu.agh.cast.map.config;
+
+import java.util.List;
+
+import pl.edu.agh.cast.map.provider.IMapProvider;
+
+public interface IMapConfigurationProvider {
+
+	boolean discCacheEnabled();
+
+	boolean discCacheLimitEnabled();
+
+	int discCacheLimit();
+
+	boolean memoryCacheEnabled();
+
+	int memoryCacheLimit();
+
+	List<IMapProvider> mapProviders();
+
+}

pl.edu.agh.cast.map/src/main/java/pl/edu/agh/cast/map/config/IMapConfigurator.java

@@ -0,0 +1,37 @@
+package pl.edu.agh.cast.map.config;
+
+import pl.edu.agh.cast.map.provider.IMapProvider;
+
+public interface IMapConfigurator extends IMapConfigurationProvider {
+
+	// Disc cache
+
+	void enableDiscCache(boolean enabled);
+
+	void enableDiscCacheLimit(boolean enabled);
+
+	/**
+	 * 
+	 * @param limit
+	 *            in MB
+	 */
+	void setDiscCacheLimit(int limit);
+
+	// Memory cache
+
+	void enableMemoryCache(boolean enabled);
+
+	/**
+	 * 
+	 * @param limit
+	 *            in MB
+	 */
+	void setMemoryCacheLimit(int limit);
+
+	// Map providers
+
+	void addMapProvider(IMapProvider mapProvider);
+
+	void removeMapProvider(IMapProvider mapProvider);
+
+}