Android Open Source - android_Findex Memory Cache

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Back to project page android_Findex.

License

The source code is released under:

Apache License

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Java Source Code

package com.lithidsw.findex.loader;
//  w  ww  .j av a2  s.c  om
import android.graphics.Bitmap;

import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;

public class MemoryCache {

    private Map<String, Bitmap> cache = Collections
            .synchronizedMap(new LinkedHashMap<String, Bitmap>(10, 1.5f, true));
    private long size = 0;
    private long limit = 100000;

    public MemoryCache() {
        setLimit(Runtime.getRuntime().maxMemory() / 4);
    }

    public void setLimit(long new_limit) {
        limit = new_limit;
    }

    public Bitmap get(String id) {
        try {
            if (!cache.containsKey(id)) {
                return null;
            }
            // NullPointerException sometimes happen here
            // http://code.google.com/p/osmdroid/issues/detail?id=78
            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() {
        if (size > limit) {
            Iterator<Entry<String, Bitmap>> iter = cache.entrySet().iterator();
            while (iter.hasNext()) {
                Entry<String, Bitmap> entry = iter.next();
                size -= getSizeInBytes(entry.getValue());
                iter.remove();
                if (size <= limit)
                    break;
            }
        }
    }

    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();
    }
}

Java Source Code List