package com.xiangyixie.picshouse.Cache;
import android.graphics.Bitmap;
import android.util.Log;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
public class MemoryCache {
private static final String TAG = "MemoryCache";
private Map<String, Bitmap> cache = Collections.synchronizedMap(
new LinkedHashMap<String, Bitmap>(10, 1.5f, true));//Last argument true for LRU ordering
private long size = 0;//current allocated size
private long limit = 1000000;//max memory in bytes
public MemoryCache() {
//use 25% of available heap size
setLimit(Runtime.getRuntime().maxMemory() / 4);
}
public void setLimit(long new_limit) {
limit = new_limit;
Log.d(TAG, "MemoryCache will use up to " + limit / 1024. / 1024. + "MB");
}
public Bitmap get(String id) {
try {
if (!cache.containsKey(id)) {
return null;
}
return cache.get(id);
} catch (NullPointerException ex) {
ex.printStackTrace();
return null;
}
}
public void put(String id, Bitmap bitmap) {
try {
if (cache.containsKey(id))
size -= getSizeInBytes(cache.get(id));
cache.put(id, bitmap);
size += getSizeInBytes(bitmap);
checkSize();
} catch (Throwable th) {
th.printStackTrace();
}
}
private void checkSize() {
Log.i(TAG, "cache size=" + size + " length=" + cache.size());
if (size > limit) {
Iterator<Map.Entry<String, Bitmap>> iter = cache.entrySet().iterator();//least recently accessed item will be the first one iterated
while (iter.hasNext()) {
Map.Entry<String, Bitmap> entry = iter.next();
size -= getSizeInBytes(entry.getValue());
iter.remove();
if (size <= limit)
break;
}
Log.i(TAG, "Clean cache. New size " + cache.size());
}
}
public void clear() {
try {
//NullPointerException sometimes happen here http://code.google.com/p/osmdroid/issues/detail?id=78
cache.clear();
size = 0;
} catch (NullPointerException ex) {
ex.printStackTrace();
}
}
long getSizeInBytes(Bitmap bitmap) {
if (bitmap == null)
return 0;
return bitmap.getRowBytes() * bitmap.getHeight();
}
}