Android開源架構Universal-Image-Loader學習無——WeakMemoryCache 和 FuzzyKeyMemoryCache

Android開源架構Universal-Image-Loader學習無——WeakMemoryCache 和 FuzzyKeyMemoryCache

 

 

 

/** * Memory cache with {@linkplain WeakReference weak references} to {@linkplain android.graphics.Bitmap bitmaps} *  * NOTE: This cache uses only weak references for stored Bitmaps. * * @author Sergey Tarasevich (nostra13[at]gmail[dot]com) * @since 1.5.3 */public class WeakMemoryCache extends BaseMemoryCache {    @Override    protected Reference createReference(Bitmap value) {        return new WeakReference(value);    }}

FuzzyKeyMemoryCache源碼：

/** * MemoryCache的裝飾者模式。為cache提供一個特殊功能：（使用Comparator）使得一些不同的keys被當做是等價的。當使用key put一些值到cache中 * 具有“相同”意義的keys將會先被移除（一般不會用到該class） * NOTE: Used for internal needs. Normally you don't need to use this class. */public class FuzzyKeyMemoryCache implements MemoryCache {     private final MemoryCache cache;    private final Comparator keyComparator;     public FuzzyKeyMemoryCache(MemoryCache cache, Comparator keyComparator) {        this.cache = cache;        this.keyComparator = keyComparator;    }     @Override    public boolean put(String key, Bitmap value) {        // Search equal key and remove this entry        synchronized (cache) {            String keyToRemove = null;            for (String cacheKey : cache.keys()) {                if (keyComparator.compare(key, cacheKey) == 0) {                    keyToRemove = cacheKey;                    break;                }            }            if (keyToRemove != null) {                cache.remove(keyToRemove);            }        }        return cache.put(key, value);    }     @Override    public Bitmap get(String key) {        return cache.get(key);    }     @Override    public Bitmap remove(String key) {        return cache.remove(key);    }     @Override    public void clear() {        cache.clear();    }     @Override    public Collection keys() {        return cache.keys();    }}