/**
* Copyright (c) 2012-2013, Michael Yang 杨福海 (www.yangfuhai.com).
*
* 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 cn.coderss.bitmap;
import android.app.ActivityManager;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.BitmapFactory;
import android.util.Log;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class BitmapCache {
private static final String TAG = "ImageCache";
//默认的内存缓存大小
private static final int DEFAULT_MEM_CACHE_SIZE = 1024 * 1024 * 8; // 8MB
//默认的磁盘缓存大小
private static final int DEFAULT_DISK_CACHE_SIZE = 1024 * 1024 * 20; // 20MB
// Compression settings when writing images to disk cache
private static final CompressFormat DEFAULT_COMPRESS_FORMAT = CompressFormat.JPEG;
private static final int DEFAULT_COMPRESS_QUALITY = 70;
private static final int DISK_CACHE_INDEX = 0;
// Constants to easily toggle various caches
private static final boolean DEFAULT_MEM_CACHE_ENABLED = true;
private static final boolean DEFAULT_DISK_CACHE_ENABLED = true;
private static final boolean DEFAULT_CLEAR_DISK_CACHE_ON_START = false;
private static final boolean DEFAULT_INIT_DISK_CACHE_ON_CREATE = false;
private LruDiskCache mDiskLruCache;
private LruMemoryCache<String, Bitmap> mMemoryCache;
private ImageCacheParams mCacheParams;
private final Object mDiskCacheLock = new Object();
private boolean mDiskCacheStarting = true;
/**
* Creating a new ImageCache object using the specified parameters.
*
* @param cacheParams The cache parameters to use to initialize the cache
*/
public BitmapCache(ImageCacheParams cacheParams) {
init(cacheParams);
}
/**
* Initialize the cache, providing all parameters.
*
* @param cacheParams The cache parameters to initialize the cache
*/
private void init(ImageCacheParams cacheParams) {
mCacheParams = cacheParams;
// Set up memory cache
if (mCacheParams.memoryCacheEnabled) {
mMemoryCache = new LruMemoryCache<String, Bitmap>(mCacheParams.memCacheSize) {
/**
* Measure item size in bytes rather than units which is more practical
* for a bitmap cache
*/
@Override
protected int sizeOf(String key, Bitmap bitmap) {
return BitmapCommonUtils.getBitmapSize(bitmap);
}
};
}
// By default the disk cache is not initialized here as it should be initialized
// on a separate thread due to disk access.
if (cacheParams.initDiskCacheOnCreate) {
// Set up disk cache
initDiskCache();
}
}
/**
* Initializes the disk cache. Note that this includes disk access so this should not be
* executed on the main/UI thread. By default an ImageCache does not initialize the disk
* cache when it is created, instead you should call initDiskCache() to initialize it on a
* background thread.
*/
public void initDiskCache() {
// Set up disk cache
synchronized (mDiskCacheLock) {
if (mDiskLruCache == null || mDiskLruCache.isClosed()) {
File diskCacheDir = mCacheParams.diskCacheDir;
if (mCacheParams.diskCacheEnabled && diskCacheDir != null) {
if (!diskCacheDir.exists()) {
diskCacheDir.mkdirs();
}
if (BitmapCommonUtils.getUsableSpace(diskCacheDir) > mCacheParams.diskCacheSize) {
try {
mDiskLruCache = LruDiskCache.open(diskCacheDir, 1, 1, mCacheParams.diskCacheSize);
} catch (final IOException e) {
mCacheParams.diskCacheDir = null;
Log.e(TAG, "initDiskCache - " + e);
}
}
}
}
mDiskCacheStarting = false;
mDiskCacheLock.notifyAll();
}
}
/**
* Adds a bitmap to both memory and disk cache.
* @param data Unique identifier for the bitmap to store
* @param bitmap The bitmap to store
*/
public void addBitmapToCache(String data, Bitmap bitmap) {
if (data == null || bitmap == null) {
return;
}
// Add to memory cache
if (mMemoryCache != null && mMemoryCache.get(data) == null) {
mMemoryCache.put(data, bitmap);
}
synchronized (mDiskCacheLock) {
// 添加到硬盘缓存
if (mDiskLruCache != null && mDiskLruCache.getDirectory()!= null ) {
if(!mDiskLruCache.getDirectory().exists())
mDiskLruCache.getDirectory().mkdirs();
final String key = FileNameGenerator.generator(data);
OutputStream out = null;
try {
LruDiskCache.Snapshot snapshot = mDiskLruCache.get(key);
if (snapshot == null) {
final LruDiskCache.Editor editor = mDiskLruCache.edit(key);
if (editor != null) {
out = editor.newOutputStream(DISK_CACHE_INDEX);
bitmap.compress(
mCacheParams.compressFormat, mCacheParams.compressQuality, out);
editor.commit();
out.close();
}
} else {
snapshot.getInputStream(DISK_CACHE_INDEX).close();
}
} catch (final IOException e) {
Log.e(TAG, "addBitmapToCache - " + e);
} catch (Exception e) {
Log.e(TAG, "addBitmapToCache - " + e);
} finally {
try {
if (out != null) {
out.close();
}
} catch (IOException e) {}
}
}
}
}
/**
* Get from memory cache.
*
* @param data Unique identifier for which item to get
* @return The bitmap if found in cache, null otherwise
*/
public Bitmap getBitmapFromMemCache(String data) {
if (mMemoryCache != null) {
final Bitmap memBitmap = mMemoryCache.get(data);
if (memBitmap != null) {
return memBitmap;
}
}
return null;
}
/**
* 获取硬盘缓存
* @param data
* @return
*/
public Bitmap getBitmapFromDiskCache(String data) {
final String key = FileNameGenerator.generator(data);
synchronized (mDiskCacheLock) {
while (mDiskCacheStarting) {
try {
mDiskCacheLock.wait();
} catch (InterruptedException e) {}
}
if (mDiskLruCache != null) {
InputStream inputStream = null;
try {
final LruDiskCache.Snapshot snapshot = mDiskLruCache.get(key);
if (snapshot != null) {
inputStream = snapshot.getInputStream(DISK_CACHE_INDEX);
if (inputStream != null) {
mMemoryCache.trimToMax();// 使用BitmapCache时，控制MaxSize
final Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
return bitmap;
}
}
} catch (final IOException e) {
Log.e(TAG, "getBitmapFromDiskCache - " + e);
} finally {
try {
if (inputStream != null) {
inputStream.close();
}
} catch (IOException e) {}
}
}
return null;
}
}
/**
* Clears both the memory and disk cache associated with this ImageCache object. Note that
* this includes disk access so this should not be executed on the main/UI thread.
*/
public void clearCache() {
clearMemoryCache();
synchronized (mDiskCacheLock) {
mDiskCacheStarting = true;
if (mDiskLruCache != null && !mDiskLruCache.isClosed()) {
try {
mDiskLruCache.delete();
} catch (IOException e) {
Log.e(TAG, "clearCache - " + e);
}
mDiskLruCache = null;
initDiskCache();
}
}
}
public void clearMemoryCache(){
if (mMemoryCache != null) {
mMemoryCache.evictAll();
}
}
/**
* Flushes the disk cache associated with this ImageCache object. Note that this includes
* disk access so this should not be executed on the main/UI thread.
*/
public void flush() {
synchronized (mDiskCacheLock) {
if (mDiskLruCache != null) {
try {
mDiskLruCache.flush();
} catch (IOException e) {
Log.e(TAG, "flush - " + e);
}
}
}
}
/**
* Closes the disk cache associated with this ImageCache object. Note that this includes
* disk access so this should not be executed on the main/UI thread.
*/
public void close() {
synchronized (mDiskCacheLock) {
if (mDiskLruCache != null) {
try {
if (!mDiskLruCache.isClosed()) {
mDiskLruCache.close();
mDiskLruCache = null;
}
} catch (IOException e) {
Log.e(TAG, "close - " + e);
}
}
}
}
/**
* A holder class that contains cache parameters.
*/
public static class ImageCacheParams {
public int memCacheSize = DEFAULT_MEM_CACHE_SIZE;
public int diskCacheSize = DEFAULT_DISK_CACHE_SIZE;
public File diskCacheDir;
public CompressFormat compressFormat = DEFAULT_COMPRESS_FORMAT;
public int compressQuality = DEFAULT_COMPRESS_QUALITY;
public boolean memoryCacheEnabled = DEFAULT_MEM_CACHE_ENABLED;
public boolean diskCacheEnabled = DEFAULT_DISK_CACHE_ENABLED;
public boolean clearDiskCacheOnStart = DEFAULT_CLEAR_DISK_CACHE_ON_START;
public boolean initDiskCacheOnCreate = DEFAULT_INIT_DISK_CACHE_ON_CREATE;
public ImageCacheParams(File diskCacheDir) {
this.diskCacheDir = diskCacheDir;
}
public ImageCacheParams(String diskCacheDir) {
this.diskCacheDir = new File(diskCacheDir);
}
/**
* 设置缓存大小
* @param context
* @param percent 百分比，值的范围是在 0.05 到 0.8之间
*/
public void setMemCacheSizePercent(Context context, float percent) {
if (percent < 0.05f || percent > 0.8f) {
throw new IllegalArgumentException("setMemCacheSizePercent - percent must be "
+ "between 0.05 and 0.8 (inclusive)");
}
memCacheSize = Math.round(percent * getMemoryClass(context) * 1024 * 1024);
}
public void setMemCacheSize(int memCacheSize) {
this.memCacheSize = memCacheSize;
}
public void setDiskCacheSize(int diskCacheSize) {
this.diskCacheSize = diskCacheSize;
}
private static int getMemoryClass(Context context) {
return ((ActivityManager) context.getSystemService(
Context.ACTIVITY_SERVICE)).getMemoryClass();
}
}
}