content: /*******************************************************************************
   * Copyright 2014 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.ext;
  
  import android.graphics.Bitmap;
  import com.nostra13.universalimageloader.cache.disc.DiskCache;
  import com.nostra13.universalimageloader.cache.disc.naming.FileNameGenerator;
  import com.nostra13.universalimageloader.utils.IoUtils;
  import com.nostra13.universalimageloader.utils.L;
  
  import java.io.BufferedOutputStream;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  
  /**
   * Disk cache based on "Least-Recently Used" principle. Adapter pattern, adapts
   * {@link com.nostra13.universalimageloader.cache.disc.impl.ext.DiskLruCache DiskLruCache} to
   * {@link com.nostra13.universalimageloader.cache.disc.DiskCache DiskCache}
   *
   * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
   * @see FileNameGenerator
   * @since 1.9.2
   */
  public class LruDiscCache implements DiskCache {
  	/** {@value */
  	public static final int DEFAULT_BUFFER_SIZE = 32 * 1024; // 32 Kb
  	/** {@value */
  	public static final Bitmap.CompressFormat DEFAULT_COMPRESS_FORMAT = Bitmap.CompressFormat.PNG;
  	/** {@value */
  	public static final int DEFAULT_COMPRESS_QUALITY = 100;
  
  	private static final String ERROR_ARG_NULL = " argument must be not null";
  	private static final String ERROR_ARG_NEGATIVE = " argument must be positive number";
  
  	protected DiskLruCache cache;
  	private File reserveCacheDir;
  
  	protected final FileNameGenerator fileNameGenerator;
  
  	protected int bufferSize = DEFAULT_BUFFER_SIZE;
  
  	protected Bitmap.CompressFormat compressFormat = DEFAULT_COMPRESS_FORMAT;
  	protected int compressQuality = DEFAULT_COMPRESS_QUALITY;
  
  	/**
  	 * @param cacheDir          Directory for file caching
  	 * @param fileNameGenerator {@linkplain com.nostra13.universalimageloader.cache.disc.naming.FileNameGenerator
  	 *                          Name generator} for cached files. Generated names must match the regex
  	 *                          <strong>[a-z0-9_-]{1,64}</strong>
  	 * @param cacheMaxSize      Max cache size in bytes. <b>0</b> means cache size is unlimited.
  	 * @throws IOException if cache can't be initialized (e.g. "No space left on device")
  	 */
  	public LruDiscCache(File cacheDir, FileNameGenerator fileNameGenerator, long cacheMaxSize) throws IOException {
  		this(cacheDir, null, fileNameGenerator, cacheMaxSize, 0);
  	}
  
  	/**
  	 * @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 {@linkplain com.nostra13.universalimageloader.cache.disc.naming.FileNameGenerator
  	 *                          Name generator} for cached files. Generated names must match the regex
  	 *                          <strong>[a-z0-9_-]{1,64}</strong>
  	 * @param cacheMaxSize      Max cache size in bytes. <b>0</b> means cache size is unlimited.
  	 * @param cacheMaxFileCount Max file count in cache. <b>0</b> means file count is unlimited.
  	 * @throws IOException if cache can't be initialized (e.g. "No space left on device")
  	 */
  	public LruDiscCache(File cacheDir, File reserveCacheDir, FileNameGenerator fileNameGenerator, long cacheMaxSize,
  			int cacheMaxFileCount) throws IOException {
  		if (cacheDir == null) {
  			throw new IllegalArgumentException("cacheDir" + ERROR_ARG_NULL);
  		}
  		if (cacheMaxSize < 0) {
  			throw new IllegalArgumentException("cacheMaxSize" + ERROR_ARG_NEGATIVE);
  		}
  		if (cacheMaxFileCount < 0) {
  			throw new IllegalArgumentException("cacheMaxFileCount" + ERROR_ARG_NEGATIVE);
  		}
  		if (fileNameGenerator == null) {
  			throw new IllegalArgumentException("fileNameGenerator" + ERROR_ARG_NULL);
  		}
  
  		if (cacheMaxSize == 0) {
  			cacheMaxSize = Long.MAX_VALUE;
  		}
  		if (cacheMaxFileCount == 0) {
  			cacheMaxFileCount = Integer.MAX_VALUE;
  		}
  
  		this.reserveCacheDir = reserveCacheDir;
  		this.fileNameGenerator = fileNameGenerator;
  		initCache(cacheDir, reserveCacheDir, cacheMaxSize, cacheMaxFileCount);
  	}
  
  	private void initCache(File cacheDir, File reserveCacheDir, long cacheMaxSize, int cacheMaxFileCount)
  			throws IOException {
  		try {
  			cache = DiskLruCache.open(cacheDir, 1, 1, cacheMaxSize, cacheMaxFileCount);
  		} catch (IOException e) {
  			L.e(e);
  			if (reserveCacheDir != null) {
  				initCache(reserveCacheDir, null, cacheMaxSize, cacheMaxFileCount);
  			}
  			if (cache == null) {
  				throw e; //new RuntimeException("Can't initialize disk cache", e);
  			}
  		}
  	}
  
  	@Override
  	public File getDirectory() {
  		return cache.getDirectory();
  	}
  
  	@Override
  	public File get(String imageUri) {
  		DiskLruCache.Snapshot snapshot = null;
  		try {
  			snapshot = cache.get(getKey(imageUri));
  			return snapshot == null ? null : snapshot.getFile(0);
  		} catch (IOException e) {
  			L.e(e);
  			return null;
  		} finally {
  			if (snapshot != null) {
  				snapshot.close();
  			}
  		}
  	}
  
  	@Override
  	public boolean save(String imageUri, InputStream imageStream, IoUtils.CopyListener listener) throws IOException {
  		DiskLruCache.Editor editor = cache.edit(getKey(imageUri));
  		if (editor == null) {
  			return false;
  		}
  
  		OutputStream os = new BufferedOutputStream(editor.newOutputStream(0), bufferSize);
  		boolean copied = false;
  		try {
  			copied = IoUtils.copyStream(imageStream, os, listener, bufferSize);
  		} finally {
  			IoUtils.closeSilently(os);
  			if (copied) {
  				editor.commit();
  			} else {
  				editor.abort();
  			}
  		}
  		return copied;
  	}
  
  	@Override
  	public boolean save(String imageUri, Bitmap bitmap) throws IOException {
  		DiskLruCache.Editor editor = cache.edit(getKey(imageUri));
  		if (editor == null) {
  			return false;
  		}
  
  		OutputStream os = new BufferedOutputStream(editor.newOutputStream(0), bufferSize);
  		boolean savedSuccessfully = false;
  		try {
  			savedSuccessfully = bitmap.compress(compressFormat, compressQuality, os);
  		} finally {
  			IoUtils.closeSilently(os);
  		}
  		if (savedSuccessfully) {
  			editor.commit();
  		} else {
  			editor.abort();
  		}
  		return savedSuccessfully;
  	}
  
  	@Override
  	public boolean remove(String imageUri) {
  		try {
  			return cache.remove(getKey(imageUri));
  		} catch (IOException e) {
  			L.e(e);
  			return false;
  		}
  	}
  
  	@Override
  	public void close() {
  		try {
  			cache.close();
  		} catch (IOException e) {
  			L.e(e);
  		}
  		cache = null;
  	}
  
  	@Override
  	public void clear() {
  		try {
  			cache.delete();
  		} catch (IOException e) {
  			L.e(e);
  		}
  		try {
  			initCache(cache.getDirectory(), reserveCacheDir, cache.getMaxSize(), cache.getMaxFileCount());
  		} catch (IOException e) {
  			L.e(e);
  		}
  	}
  
  	private String getKey(String imageUri) {
  		return fileNameGenerator.generate(imageUri);
  	}
  
  	public void setBufferSize(int bufferSize) {
  		this.bufferSize = bufferSize;
  	}
  
  	public void setCompressFormat(Bitmap.CompressFormat compressFormat) {
  		this.compressFormat = compressFormat;
  	}
  
  	public void setCompressQuality(int compressQuality) {
  		this.compressQuality = compressQuality;
  	}
  }
  