Android Open Source - AUIL-for-volley Largest Limited Memory Cache

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License

The source code is released under:

Apache License

Java Source Code

/*******************************************************************************
 * Copyright 2011-2013 Sergey Tarasevich
 */*  w ww.  j  av  a  2  s.  co m*/
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************/
package com.nostra13.universalimageloader.cache.memory.impl;

import android.graphics.Bitmap;
import com.nostra13.universalimageloader.cache.memory.LimitedMemoryCache;

import java.lang.ref.Reference;
import java.lang.ref.WeakReference;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

/**
 * Limited {@link Bitmap bitmap} cache. Provides {@link Bitmap bitmaps} storing. Size of all stored bitmaps will not to
 * exceed size limit. When cache reaches limit size then the bitmap which used the least frequently is deleted from
 * cache.<br />
 * <br />
 * <b>NOTE:</b> This cache uses strong and weak references for stored Bitmaps. Strong references - for limited count of
 * Bitmaps (depends on cache size), weak references - for all other cached Bitmaps.
 *
 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
 * @since 1.0.0
 */
public class LargestLimitedMemoryCache extends LimitedMemoryCache<String, Bitmap> {
  /**
   * Contains strong references to stored objects (keys) and last object usage date (in milliseconds). If hard cache
   * size will exceed limit then object with the least frequently usage is deleted (but it continue exist at
   * {@link #softMap} and can be collected by GC at any time)
   */
  private final Map<Bitmap, Integer> valueSizes = Collections.synchronizedMap(new HashMap<Bitmap, Integer>());

  public LargestLimitedMemoryCache(int sizeLimit) {
    super(sizeLimit);
  }

  @Override
  public boolean put(String key, Bitmap value) {
    if (super.put(key, value)) {
      valueSizes.put(value, getSize(value));
      return true;
    } else {
      return false;
    }
  }

  @Override
  public void remove(String key) {
    Bitmap value = super.get(key);
    if (value != null) {
      valueSizes.remove(value);
    }
    super.remove(key);
  }

  @Override
  public void clear() {
    valueSizes.clear();
    super.clear();
  }

  @Override
  protected int getSize(Bitmap value) {
    return value.getRowBytes() * value.getHeight();
  }

  @Override
  protected Bitmap removeNext() {
    Integer maxSize = null;
    Bitmap largestValue = null;
    Set<Entry<Bitmap, Integer>> entries = valueSizes.entrySet();
    synchronized (valueSizes) {
      for (Entry<Bitmap, Integer> entry : entries) {
        if (largestValue == null) {
          largestValue = entry.getKey();
          maxSize = entry.getValue();
        } else {
          Integer size = entry.getValue();
          if (size > maxSize) {
            maxSize = size;
            largestValue = entry.getKey();
          }
        }
      }
    }
    valueSizes.remove(largestValue);
    return largestValue;
  }

  @Override
  protected Reference<Bitmap> createReference(Bitmap value) {
    return new WeakReference<Bitmap>(value);
  }
}

Java Source Code List

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