content: /*******************************************************************************
   * Copyright 2011-2013 Sergey Tarasevich
   *
   * 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.MemoryCache;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Decorator for {@link MemoryCache}. Provides special feature for cache: if some cached object age exceeds defined
   * value then this object will be removed from cache.
   *
   * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
   * @see MemoryCache
   * @since 1.3.1
   */
  public class LimitedAgeMemoryCache implements MemoryCache {
  
  	private final MemoryCache cache;
  
  	private final long maxAge;
  	private final Map<String, Long> loadingDates = Collections.synchronizedMap(new HashMap<String, Long>());
  
  	/**
  	 * @param cache  Wrapped memory cache
  	 * @param maxAge Max object age <b>(in seconds)</b>. If object age will exceed this value then it'll be removed from
  	 *               cache on next treatment (and therefore be reloaded).
  	 */
  	public LimitedAgeMemoryCache(MemoryCache cache, long maxAge) {
  		this.cache = cache;
  		this.maxAge = maxAge * 1000; // to milliseconds
  	}
  
  	@Override
  	public boolean put(String key, Bitmap value) {
  		boolean putSuccesfully = cache.put(key, value);
  		if (putSuccesfully) {
  			loadingDates.put(key, System.currentTimeMillis());
  		}
  		return putSuccesfully;
  	}
  
  	@Override
  	public Bitmap get(String key) {
  		Long loadingDate = loadingDates.get(key);
  		if (loadingDate != null && System.currentTimeMillis() - loadingDate > maxAge) {
  			cache.remove(key);
  			loadingDates.remove(key);
  		}
  
  		return cache.get(key);
  	}
  
  	@Override
  	public Bitmap remove(String key) {
  		loadingDates.remove(key);
  		return cache.remove(key);
  	}
  
  	@Override
  	public Collection<String> keys() {
  		return cache.keys();
  	}
  
  	@Override
  	public void clear() {
  		cache.clear();
  		loadingDates.clear();
  	}
  }
  