Android Open Source - SimpleReader Memory Cache

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Back to project page SimpleReader.

License

The source code is released under:

Apache License

Java Source Code

package com.dreamteam.app.img;
/*from  w w w . ja v  a  2s.  co m*/
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;

import android.graphics.Bitmap;

import com.litesuits.android.log.Log;

public class MemoryCache {
  private Map<String, Bitmap> cache = Collections.synchronizedMap(
      new LinkedHashMap<String, Bitmap>(10, 1.5f, true));
  // ?????????????????0?????????????????????????
  private long size = 0;
  // ?????????????
  private long limit = 1000000;
  
  public MemoryCache() {
    // ????????????????25%
    setLimit(Runtime.getRuntime().maxMemory()/10);
  }
  
  public void setLimit(long limit) {
    this.limit = limit;
    Log.w("MemoryCache", "memory cache of image will set to : " + limit / 1024 /1024 + "MB");
  }
  
  public Bitmap getCache(String key) {
    if(key == null || "".equals(key)) {
      Log.e("MemoryCache", "parameter key is null");
      return null;
    }
    
    if(cache.containsKey(key)) {
      return cache.get(key);
    }else {
      return null;
    }
  }
  
  public void put(String key, Bitmap bitmap) {
    if(key == null || bitmap == null) {
      Log.e("MemoryCache", "parameter cannot be null");
      return;
    }
    if(cache.containsKey(key)) {
      return;
    }else {
      cache.put(key, bitmap);
      size += getSizeInBytes(bitmap);
      checkCacheSize();
    }
  }
  
  public void clear() {
    cache.clear();
  }
  
  public void checkCacheSize() {
    Log.w("MemoryCache", "check cache...");
    Log.w("MemoryCache", "cache map size : " + size + " ,map length : "+ cache.size());
    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;
      }
      Log.w("MemoryCache", "Clean cache. New size " + cache.size());
    }
    
  }
  
  public long getSizeInBytes(Bitmap bitmap) {
    if(bitmap == null) {
      Log.e("MemoryCache", "parameter bitmap is null");
      return -1;
    }
    return bitmap.getRowBytes() * bitmap.getHeight();
  }
}

Java Source Code List

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