Issue 4903 - Allow to specify file system root

libadblockplus-android-settings/src/org/adblockplus/libadblockplus/android/settings/AdblockHelper.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 72 matching lines @@
 
   public AdblockSettingsStorage getStorage()
   {
     return storage;
   }
 
   /**
    * Init with context
    * @param context application context
    * @param basePath file system root to store files
+   *
+   *                 Adblock Plus library will download subscription files and store them on
+   *                 the path passed. The path should exist and the directory content should not be
+   *                 cleared out occasionally. Using `context.getCacheDir().getAbsolutePath()` is not
+   *                 recommended because it can be cleared by the system.
    * @param developmentBuild debug or release?
    * @param preferenceName Shared Preferences name
    */
   public void init(Context context, String basePath, boolean developmentBuild, String preferenceName)
   {
     this.context = context.getApplicationContext();
     this.basePath = basePath;
     this.developmentBuild = developmentBuild;
     this.preferenceName = preferenceName;
-  }
-
-  /**
-   * Init with context
-   * @param context application context
-   * @param developmentBuild debug or release?
-   * @param preferenceName Shared Preferences name
-   */
-  public void init(Context context, boolean developmentBuild, String preferenceName)

[anton, 2017/02/16 11:43:44]

for back compatibility. do we need it?

[sergei, 2017/03/13 08:49:23]

Could it be marked as deprecated and I think we should also update readme file.

[anton, 2017/03/13 09:16:32]

It could be marked with @Deprecated java annotation, but i would not say the
method is deprecated.
I will update README file

-  {
-    init(context, context.getCacheDir().getAbsolutePath(), developmentBuild, preferenceName);

[anton, 2017/02/16 11:47:15]

for back compatibility it's better to getCacheDir(). but because app cache can
be cleared by the system and we don't want it it would be better to pass
https://developer.android.com/reference/android/content/Context.html#getDataD....
what would you prefer?

[anton, 2017/02/16 11:49:24]

getDataDir is available starting api 24 only. probably we should use
https://developer.android.com/reference/android/content/Context.html#getFiles...
instead

   }
 
   private void createAdblock()
   {
     Log.d(TAG, "Creating adblock engine ...");
 
     // read and apply current settings
     SharedPreferences prefs = context.getSharedPreferences(preferenceName, Context.MODE_PRIVATE);
     storage = new SharedPrefsStorage(prefs);
 
@@ skipping 103 matching lines @@
    */
   public synchronized void release()
   {
     if (referenceCounter.decrementAndGet() == 0)
     {
       waitForReady();
       disposeAdblock();
     }
   }
 }