content: /*******************************************************************************
   * Copyright 2011-2013 Sergey Tarasevich
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *******************************************************************************/
  package com.nostra13.universalimageloader.utils;
  
  import android.graphics.Bitmap;
  
  import com.nostra13.universalimageloader.cache.memory.MemoryCache;
  import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
  import com.nostra13.universalimageloader.core.assist.ImageSize;
  
  import java.util.ArrayList;
  import java.util.Comparator;
  import java.util.List;
  
  /**
   * Utility for generating of keys for memory cache, key comparing and other work with memory cache
   *
   * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
   * @since 1.6.3
   */
  public final class MemoryCacheUtils {
  
  	private static final String URI_AND_SIZE_SEPARATOR = "_";
  	private static final String WIDTH_AND_HEIGHT_SEPARATOR = "x";
  
  	private MemoryCacheUtils() {
  	}
  
  	/**
  	 * Generates key for memory cache for incoming image (URI + size).<br />
  	 * Pattern for cache key - <b>[imageUri]_[width]x[height]</b>.
  	 */
  	public static String generateKey(String imageUri, ImageSize targetSize) {
  		return new StringBuilder(imageUri).append(URI_AND_SIZE_SEPARATOR).append(targetSize.getWidth()).append(WIDTH_AND_HEIGHT_SEPARATOR).append(targetSize.getHeight()).toString();
  	}
  
  	public static Comparator<String> createFuzzyKeyComparator() {
  		return new Comparator<String>() {
  			@Override
  			public int compare(String key1, String key2) {
  				String imageUri1 = key1.substring(0, key1.lastIndexOf(URI_AND_SIZE_SEPARATOR));
  				String imageUri2 = key2.substring(0, key2.lastIndexOf(URI_AND_SIZE_SEPARATOR));
  				return imageUri1.compareTo(imageUri2);
  			}
  		};
  	}
  
  	/**
  	 * Searches all bitmaps in memory cache which are corresponded to incoming URI.<br />
  	 * <b>Note:</b> Memory cache can contain multiple sizes of the same image if only you didn't set
  	 * {@link ImageLoaderConfiguration.Builder#denyCacheImageMultipleSizesInMemory()
  	 * denyCacheImageMultipleSizesInMemory()} option in {@linkplain ImageLoaderConfiguration configuration}
  	 */
  	public static List<Bitmap> findCachedBitmapsForImageUri(String imageUri, MemoryCache memoryCache) {
  		List<Bitmap> values = new ArrayList<Bitmap>();
  		for (String key : memoryCache.keys()) {
  			if (key.startsWith(imageUri)) {
  				values.add(memoryCache.get(key));
  			}
  		}
  		return values;
  	}
  
  	/**
  	 * Searches all keys in memory cache which are corresponded to incoming URI.<br />
  	 * <b>Note:</b> Memory cache can contain multiple sizes of the same image if only you didn't set
  	 * {@link ImageLoaderConfiguration.Builder#denyCacheImageMultipleSizesInMemory()
  	 * denyCacheImageMultipleSizesInMemory()} option in {@linkplain ImageLoaderConfiguration configuration}
  	 */
  	public static List<String> findCacheKeysForImageUri(String imageUri, MemoryCache memoryCache) {
  		List<String> values = new ArrayList<String>();
  		for (String key : memoryCache.keys()) {
  			if (key.startsWith(imageUri)) {
  				values.add(key);
  			}
  		}
  		return values;
  	}
  
  	/**
  	 * Removes from memory cache all images for incoming URI.<br />
  	 * <b>Note:</b> Memory cache can contain multiple sizes of the same image if only you didn't set
  	 * {@link ImageLoaderConfiguration.Builder#denyCacheImageMultipleSizesInMemory()
  	 * denyCacheImageMultipleSizesInMemory()} option in {@linkplain ImageLoaderConfiguration configuration}
  	 */
  	public static void removeFromCache(String imageUri, MemoryCache memoryCache) {
  		List<String> keysToRemove = new ArrayList<String>();
  		for (String key : memoryCache.keys()) {
  			if (key.startsWith(imageUri)) {
  				keysToRemove.add(key);
  			}
  		}
  		for (String keyToRemove : keysToRemove) {
  			memoryCache.remove(keyToRemove);
  		}
  	}
  }
  