From 42516faa2e2aa57114e824a262396e443563a140 Mon Sep 17 00:00:00 2001
From: Andrew Dolgov <fox@madoka.volgo-balt.ru>
Date: Wed, 7 Dec 2011 14:59:30 +0300
Subject: implement offline image caching

---
 src/org/fox/ttrss/ImageCacheService.java | 181 +++++++++++++++++++++++++++++++
 1 file changed, 181 insertions(+)
 create mode 100644 src/org/fox/ttrss/ImageCacheService.java

(limited to 'src/org/fox/ttrss/ImageCacheService.java')

diff --git a/src/org/fox/ttrss/ImageCacheService.java b/src/org/fox/ttrss/ImageCacheService.java
new file mode 100644
index 00000000..999b7437
--- /dev/null
+++ b/src/org/fox/ttrss/ImageCacheService.java
@@ -0,0 +1,181 @@
+package org.fox.ttrss;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.net.URLConnection;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Date;
+
+import android.app.ActivityManager;
+import android.app.IntentService;
+import android.app.NotificationManager;
+import android.app.ActivityManager.RunningServiceInfo;
+import android.content.Intent;
+import android.os.Environment;
+import android.util.Log;
+
+public class ImageCacheService extends IntentService {
+
+	private final String TAG = this.getClass().getSimpleName();
+
+	public static final int NOTIFY_DOWNLOADING = 1;
+	
+	private static final String CACHE_PATH = "/org.fox.ttrss/image-cache/";
+
+	private int m_imagesDownloaded = 0;
+	
+	private NotificationManager m_nmgr;
+	
+	public ImageCacheService() {
+		super("ImageCacheService");
+	}
+
+	private boolean isDownloadServiceRunning() {
+	    ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
+	    for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
+	        if ("org.fox.ttrss.OfflineDownloadService".equals(service.service.getClassName())) {
+	            return true;
+	        }
+	    }
+	    return false;
+	}
+	
+
+	@Override
+	public void onCreate() {
+		super.onCreate();
+		m_nmgr = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
+	}
+
+	protected static boolean isUrlCached(String url) {
+		String hashedUrl = md5(url);
+		
+		File storage = Environment.getExternalStorageDirectory();
+		
+		File file = new File(storage.getAbsolutePath() + CACHE_PATH + "/" + hashedUrl + ".png");
+		
+		return file.exists();
+	}
+
+	protected static String getCacheFileName(String url) {
+		String hashedUrl = md5(url);
+		
+		File storage = Environment.getExternalStorageDirectory();
+		
+		File file = new File(storage.getAbsolutePath() + CACHE_PATH + "/" + hashedUrl + ".png");
+		
+		return file.getAbsolutePath();
+	}
+	
+	protected static void cleanupCache(boolean deleteAll) {
+		if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
+			File storage = Environment.getExternalStorageDirectory();
+			File cachePath = new File(storage.getAbsolutePath() + CACHE_PATH);
+		
+			long now = new Date().getTime();
+			
+			if (cachePath.isDirectory()) {
+				for (File file : cachePath.listFiles()) {
+					if (deleteAll || now - file.lastModified() > 1000*60*60*24*7) {
+						file.delete();
+					}					
+				}				
+			}
+		}
+	}
+
+	protected static String md5(String s) {
+		try {
+			MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
+	        digest.update(s.getBytes());
+	        byte messageDigest[] = digest.digest();
+	        
+	        StringBuffer hexString = new StringBuffer();
+	        for (int i=0; i<messageDigest.length; i++)
+	            hexString.append(Integer.toHexString(0xFF & messageDigest[i]));
+	        
+	        return hexString.toString();
+	        
+		} catch (NoSuchAlgorithmException e) {
+			e.printStackTrace();
+		}
+		
+		return null;
+	}
+	
+	private InputStream getStream(String urlString) {
+	    try {
+	        URL url = new URL(urlString);
+	        URLConnection urlConnection = url.openConnection();
+	        urlConnection.setConnectTimeout(250);
+	        return urlConnection.getInputStream();
+	    } catch (Exception ex) {
+	        return null;
+	    }
+	}
+	@Override
+	protected void onHandleIntent(Intent intent) {
+		String url = intent.getStringExtra("url");
+
+		//Log.d(TAG, "got request to download URL=" + url);
+		
+		if (!Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()))
+			return;
+		
+		String hashedUrl = md5(url);
+		
+		File storage = Environment.getExternalStorageDirectory();
+		File cachePath = new File(storage.getAbsolutePath() + CACHE_PATH);
+		if (!cachePath.exists()) cachePath.mkdirs();
+		
+		if (cachePath.isDirectory() && hashedUrl != null) {
+			File outputFile = new File(cachePath.getAbsolutePath() + "/" + hashedUrl + ".png");
+			
+			if (!outputFile.exists()) {
+
+				//Log.d(TAG, "downloading to " + outputFile.getAbsolutePath());
+
+				InputStream is = getStream(url);
+				
+				if (is != null) {
+					try {					
+						FileOutputStream fos = new FileOutputStream(outputFile);
+						
+						byte[] buffer = new byte[1024];
+						int len = 0;
+						while ((len = is.read(buffer)) != -1) {
+						    fos.write(buffer, 0, len);
+						}
+						
+						fos.close();
+						is.close();
+						
+						m_imagesDownloaded++;
+						
+					} catch (IOException e) {
+						e.printStackTrace();
+					}
+				}
+			}			
+		}
+	}
+	
+	@Override
+	public void onDestroy() {
+		super.onDestroy();
+
+	    if (!isDownloadServiceRunning()) {
+	    	m_nmgr.cancel(NOTIFY_DOWNLOADING);
+	    	
+			Intent success = new Intent();
+			success.setAction(OfflineDownloadService.INTENT_ACTION_SUCCESS);
+			success.addCategory(Intent.CATEGORY_DEFAULT);
+			sendBroadcast(success);
+	    }
+	}
+	
+}
-- 
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