/*
* Copyright (C) 2010 mAPPn.Inc
*
* 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.mappn.gfan.common.util;
import java.io.File;
import java.lang.ref.SoftReference;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import android.graphics.Bitmap;
import android.os.Environment;
import android.os.Process;
import com.mappn.gfan.Constants;
/**
* Cache Manager
*
* For caching something like drawables, objects...
*
* @author andrew.wang
*
*/
public class CacheManager {
private static CacheManager mInstance;
// the max cached icon in the SD-Card
private static final int MAX_IMAGE_IN_SDCARD = 100;
// cache in the memory
private LinkedHashMap<String, Bitmap> mDrawableMap = new LinkedHashMap<String, Bitmap>();
private SoftReference<LinkedHashMap<String, Bitmap>> mDrawableCache =
new SoftReference<LinkedHashMap<String, Bitmap>>(mDrawableMap);
private ArrayList<String> mNewIcons = new ArrayList<String>();
private CacheManager() {
// loadIconsFromSDCard();
}
public static CacheManager getInstance() {
if (mInstance == null) {
mInstance = new CacheManager();
}
return mInstance;
}
/**
* Get the icon list from memory cache
*/
private LinkedHashMap<String, Bitmap> getMemoCache() {
if (mDrawableCache == null) {
mDrawableCache = new SoftReference<LinkedHashMap<String, Bitmap>>(mDrawableMap);
return mDrawableMap;
}
return mDrawableCache.get();
}
/**
* Check whether the drawable had been cached
*
* @param key
* drawable uri
* @return ture : exist false : not exist
*/
public boolean existsDrawable(String key) {
// fetch the drawable from memory
HashMap<String, Bitmap> memoCache = getMemoCache();
if (memoCache.containsKey(StringUtils.getFileNameFromUrl(key))) return true;
return false;
}
/**
* 开始缓存图片
*/
public synchronized void cacheDrawable(String url, Bitmap image) {
if (image == null) {
return;
}
// put the icon in the memory
LinkedHashMap<String, Bitmap> memoCache = getMemoCache();
if (memoCache == null) {
return;
}
String key = StringUtils.getFileNameFromUrl(url);
if(memoCache.size() < MAX_IMAGE_IN_SDCARD) {
memoCache.put(key, image);
return;
}
// reach here means L1 is full, reorder current stack
Iterator<String> iterator = memoCache.keySet().iterator();
if (iterator.hasNext()) {
// recycle the bitmap
String oldBitmapUrl = (String) iterator.next();
memoCache.remove(oldBitmapUrl);
// reorder the new image into L1 cache stack
memoCache.put(key, image);
}
return;
}
/**
* 从缓存中获取图片
* @param url 图片的HTTP资源的地址
*/
public Bitmap getDrawableFromCache(String url) {
// retrieve bitmap from cache
final String urlFileName = StringUtils.getFileNameFromUrl(url);
HashMap<String, Bitmap> memoCache = getMemoCache();
return memoCache.get(urlFileName);
}
// /**
// * 将缓存图片存入SD卡
// */
// public void close() {
//
// // check the sd-card status
// if (!Utils.isSdcardWritable()) {
// clearFromMemory();
// Utils.D("save icons failed because sd card is not writable");
// return;
// }
//
// new Thread() {
//
// @Override
// public void run() {
// // make this thread in background priority
// setPriority(Process.THREAD_PRIORITY_BACKGROUND);
//
// File cacheDirectory = new File(Environment.getExternalStorageDirectory(),
// Constants.IMAGE_CACHE_DIR);
//
// if (!cacheDirectory.exists()) {
// Utils.V("cache dir not exist, make it immediately success");
// if(cacheDirectory.mkdirs()) {
// Utils.V("cache dir not exist, make it immediately success");
//
// HashMap<String, Bitmap> memoCache = getMemoCache();
// if (memoCache != null) {
// final int length = mNewIcons.size();
// try {
// for (int i = 0; i < length; i++) {
// String key = mNewIcons.get(i);
// final Bitmap bmp = memoCache.get(key);
// if (bmp == null) {
// continue;
// }
// FileOutputStream fos = null;
// File file = new File(cacheDirectory, key);
// if (file.exists()) {
// continue;
// }
// fos = new FileOutputStream(file);
// bmp.compress(CompressFormat.PNG, 100, fos);
// fos.close();
// }
// } catch (FileNotFoundException e) {
// Utils.D("save icon fail because make file error", e);
// } catch (IOException e) {
// Utils.D("save icon fail because IOException", e);
// }
// }
// } else {
// Utils.V("cache dir not exist, make it immediately fail");
// }
// }
// // clear all the cache
// clearFromMemory();
// }
// }.start();
// }
// /*
// * 从SD卡加载缓存图片
// */
// private void loadIconsFromSDCard() {
//
// // check the sd-card status
// if (!Utils.isSdcardReadable()) {
// Utils.V("load icons failed because sd card is not readable");
// return;
// }
//
// new Thread() {
// @Override
// public void run() {
// // make this thread in background priority
// setPriority(Process.THREAD_PRIORITY_BACKGROUND);
//
// File cacheDirectory = new File(Environment.getExternalStorageDirectory(),
// Constants.IMAGE_CACHE_DIR);
// if (cacheDirectory.exists()) {
// File[] files = cacheDirectory.listFiles();
// int length = files.length;
// if (length > MAX_IMAGE_IN_SDCARD) {
// // 防止缓存文件冗余，清除超过最大缓存数的文件
// length = MAX_IMAGE_IN_SDCARD;
// for (int i = length, len = files.length; i < len; i++) {
// files[i].delete();
// }
// }
//
// HashMap<String, Bitmap> memoCache = getMemoCache();
// if (memoCache == null) {
// return;
// }
// synchronized (CacheManager.this) {
// try {
// for (int i = 0; i < length; i++) {
// final String fileName = files[i].getName();
// Bitmap bmp = BitmapFactory.decodeFile(files[i].getAbsolutePath());
// memoCache.put(fileName, bmp);
// }
// } catch (OutOfMemoryError e) {
// Utils.W("load icon from sd card occur OOM error");
// }
// }
// }
// }
// }.start();
// }
/**
* 当内存不足时清除所有缓存包括应用退出时
*/
public void clearFromMemory() {
if (mNewIcons != null) {
mNewIcons.clear();
}
if (mDrawableMap != null) {
mDrawableMap.clear();
mDrawableMap = null;
}
if (mDrawableCache != null) {
mDrawableCache.clear();
mDrawableCache = null;
}
mInstance = null;
}
/**
* 从磁盘清除缓存
*/
public void clearFromFile() {
Thread clearTask = new Thread() {
@Override
public void run() {
File cacheDirectory = new File(Environment.getExternalStorageDirectory(),
Constants.IMAGE_CACHE_DIR);
if (cacheDirectory.exists()) {
File[] files = cacheDirectory.listFiles();
for (File file : files) {
file.delete();
}
}
}
};
clearTask.setPriority(Process.THREAD_PRIORITY_BACKGROUND);
clearTask.start();
}
}