Issue 4485 - Clear cache directory

src/org/adblockplus/sbrowser/contentblocker/engine/Engine.java

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 236 matching lines @@
     this.lock();
     try
     {
       Log.d(TAG, "Writing filters...");
       final File filterFile = this.subscriptions.createAndWriteFile();
 
       final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.serviceContext);
       final String key = this.serviceContext.getString(R.string.key_cached_filter_path);
       prefs.edit().putString(key, filterFile.getAbsolutePath()).commit();
 
+      Log.d(TAG, "Cleaning up cache...");
+      final File dummyFile = getDummyFilterFile(this.serviceContext);
+      final File[] cacheDirFiles = getFilterCacheDir(this.serviceContext).listFiles();
+      if (cacheDirFiles != null)
+      {
+        for (final File file : cacheDirFiles)
+        {
+          if (!file.equals(dummyFile) && !file.equals(filterFile))
+          {
+            Log.d(TAG, "Deleting file:" + file);
+            file.delete();
+          }
+        }
+      }
     }
     catch (IOException e)
     {
       Log.e(TAG, "Failed to write filters", e);
     }
     finally
     {
       this.unlock();
     }
   }
@@ skipping 443 matching lines @@
       Log.d(TAG, headers.toString());
       this.downloader.enqueueDownload(this.createDownloadURL(sub), sub.getId(), headers);
     }
   }
 
   public void connectivityChanged()
   {
     this.downloader.connectivityChanged();
   }
 }