package com.nostra13.universalimageloader.core.assist;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import android.graphics.Bitmap;
import com.nostra13.universalimageloader.cache.memory.MemoryCacheAware;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
/**
* Utility for generating of keys for memory cache, key comparing and other work with memory cache
*
* @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
*/
public final class MemoryCacheUtil {
private static final String URI_AND_SIZE_SEPARATOR = "_";
private static final String MEMORY_CACHE_KEY_FORMAT = "%1$s" + URI_AND_SIZE_SEPARATOR + "%2$dx%3$d";
private MemoryCacheUtil() {
}
/**
* Generates key for memory cache for incoming image (URI + size).<br />
* Pattern for cache key - {@value #MEMORY_CACHE_KEY_FORMAT}, where (1) - image URI, (2) - image width, (3) - image
* height.
*/
public static String generateKey(String imageUri, ImageSize targetSize) {
return String.format(MEMORY_CACHE_KEY_FORMAT, imageUri, targetSize.getWidth(), targetSize.getHeight());
}
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, MemoryCacheAware<String, Bitmap> 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, MemoryCacheAware<String, Bitmap> 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, MemoryCacheAware<String, Bitmap> 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);
}
}
}