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.disc.impl;
  
  import android.graphics.Bitmap;
  import com.nostra13.universalimageloader.cache.disc.naming.FileNameGenerator;
  import com.nostra13.universalimageloader.core.DefaultConfigurationFactory;
  import com.nostra13.universalimageloader.utils.IoUtils;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Cache which deletes files which were loaded more than defined time. Cache size is unlimited.
   *
   * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
   * @since 1.3.1
   */
  public class LimitedAgeDiscCache extends BaseDiscCache {
  
  	private final long maxFileAge;
  
  	private final Map<File, Long> loadingDates = Collections.synchronizedMap(new HashMap<File, Long>());
  
  	/**
  	 * @param cacheDir Directory for file caching
  	 * @param maxAge   Max file age (in seconds). If file age will exceed this value then it'll be removed on next
  	 *                 treatment (and therefore be reloaded).
  	 */
  	public LimitedAgeDiscCache(File cacheDir, long maxAge) {
  		this(cacheDir, null, DefaultConfigurationFactory.createFileNameGenerator(), maxAge);
  	}
  
  	/**
  	 * @param cacheDir Directory for file caching
  	 * @param maxAge   Max file age (in seconds). If file age will exceed this value then it'll be removed on next
  	 *                 treatment (and therefore be reloaded).
  	 */
  	public LimitedAgeDiscCache(File cacheDir, File reserveCacheDir, long maxAge) {
  		this(cacheDir, reserveCacheDir, DefaultConfigurationFactory.createFileNameGenerator(), maxAge);
  	}
  
  	/**
  	 * @param cacheDir          Directory for file caching
  	 * @param reserveCacheDir   null-ok; Reserve directory for file caching. It's used when the primary directory isn't available.
  	 * @param fileNameGenerator Name generator for cached files
  	 * @param maxAge            Max file age (in seconds). If file age will exceed this value then it'll be removed on next
  	 *                          treatment (and therefore be reloaded).
  	 */
  	public LimitedAgeDiscCache(File cacheDir, File reserveCacheDir, FileNameGenerator fileNameGenerator, long maxAge) {
  		super(cacheDir, reserveCacheDir, fileNameGenerator);
  		this.maxFileAge = maxAge * 1000; // to milliseconds
  	}
  
  	@Override
  	public File get(String imageUri) {
  		File file = super.get(imageUri);
  		if (file != null && file.exists()) {
  			boolean cached;
  			Long loadingDate = loadingDates.get(file);
  			if (loadingDate == null) {
  				cached = false;
  				loadingDate = file.lastModified();
  			} else {
  				cached = true;
  			}
  
  			if (System.currentTimeMillis() - loadingDate > maxFileAge) {
  				file.delete();
  				loadingDates.remove(file);
  			} else if (!cached) {
  				loadingDates.put(file, loadingDate);
  			}
  		}
  		return file;
  	}
  
  	@Override
  	public boolean save(String imageUri, InputStream imageStream, IoUtils.CopyListener listener) throws IOException {
  		boolean saved = super.save(imageUri, imageStream, listener);
  		rememberUsage(imageUri);
  		return saved;
  	}
  
  	@Override
  	public boolean save(String imageUri, Bitmap bitmap) throws IOException {
  		boolean saved = super.save(imageUri, bitmap);
  		rememberUsage(imageUri);
  		return saved;
  	}
  
  	@Override
  	public boolean remove(String imageUri) {
  		loadingDates.remove(getFile(imageUri));
  		return super.remove(imageUri);
  	}
  
  	@Override
  	public void clear() {
  		super.clear();
  		loadingDates.clear();
  	}
  
  	private void rememberUsage(String imageUri) {
  		File file = getFile(imageUri);
  		long currentTime = System.currentTimeMillis();
  		file.setLastModified(currentTime);
  		loadingDates.put(file, currentTime);
  	}
  }