Fix free storage space check for all APIs

[Stypox]

What is it?

• Bugfix (user facing)
• Feature (user facing)
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

The previous code for obtaining free storage space was broken:

• It had some logical flaws in the checks being performed (e.g. why an SDK_INT check was before the function call, while another was inside it?)
• It didn't work at all for sdcard or other storages that don't have an UUID (don't ask me why the sdcard on the emulator did not have an UUID, who knows).
• It crashed with non-SAF files, see Release v0.27.0 (please TEST!) #10930 (comment)

This PR checks for free storage according to https://stackoverflow.com/q/31171838. It uses Os.statvfs(filePath) on non-SAF files, and Os.fstatvfs(fileDescriptor) on SAF files. Note that for SAF files a file descriptor needs to be opened in read mode, but I checked and this does not seem to create a file, and works when the file does not exist (which is basically always the case since it's the file we want to download). Also see https://pubs.opengroup.org/onlinepubs/9699919799/functions/fstatvfs.html.

I tested on API 22 emulated (both SAF and non-SAF), API 33 emulated (SAF), API 33 device (SAF) and checked the actual values returned by getFreeStorageSpace() both on sdcard and internal storage, and everything was correct.

Fixes the following issue(s)

• Release v0.27.0 (please TEST!) #10930 (comment)

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR. You can find more info and a video demonstration on this wiki page.

Due diligence

• I read the contribution guidelines.

[somos61]

Tested on Android 7.0 and 7.1.2, works flawless now, thanks!
But for Android 9 have a crash downloading with SAF turned on. Dont know if it matters, but dwnl string in settings looks like 'content://com.android.providers.downloads.documents/tree/downloads' now
When SAF is off, downloads fine yet (for A9)

Exception

• User Action: ui error
• Request: ACRA report
• Content Country: US
• Content Language: en-US
• App Language: en_US
• Service: none
• Version: 0.27.0
• OS: Linux Android 9 - 28

Crash log

java.lang.IllegalArgumentException: For input string: "downloads"
	at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:165)
	at android.database.DatabaseUtils.readExceptionWithFileNotFoundExceptionFromParcel(DatabaseUtils.java:146)
	at android.content.ContentProviderProxy.openTypedAssetFile(ContentProviderNative.java:698)
	at android.content.ContentResolver.openTypedAssetFileDescriptor(ContentResolver.java:1458)
	at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:1295)
	at android.content.ContentResolver.openFileDescriptor(ContentResolver.java:1148)
	at android.content.ContentResolver.openFileDescriptor(ContentResolver.java:1102)
	at org.schabi.newpipe.streams.io.StoredDirectoryHelper.getFreeStorageSpace(StoredDirectoryHelper.java:199)
	at org.schabi.newpipe.download.DownloadDialog.prepareSelectedDownload(DownloadDialog.java:863)
	at org.schabi.newpipe.download.DownloadDialog.lambda$initToolbar$1(DownloadDialog.java:353)
	at org.schabi.newpipe.download.DownloadDialog.$r8$lambda$eftfC3lumhpNMhhwp_4dKbyeS0U(Unknown Source:0)
	at org.schabi.newpipe.download.DownloadDialog$$ExternalSyntheticLambda9.onMenuItemClick(Unknown Source:2)
	at androidx.appcompat.widget.Toolbar$1.onMenuItemClick(Toolbar.java:225)
	at androidx.appcompat.widget.ActionMenuView$MenuBuilderCallback.onMenuItemSelected(ActionMenuView.java:781)
	at androidx.appcompat.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:836)
	at androidx.appcompat.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:159)
	at androidx.appcompat.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:987)
	at androidx.appcompat.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:977)
	at androidx.appcompat.widget.ActionMenuView.invokeItem(ActionMenuView.java:625)
	at androidx.appcompat.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:156)
	at android.view.View.performClick(View.java:6597)
	at android.view.View.performClickInternal(View.java:6574)
	at android.view.View.access$3100(View.java:778)
	at android.view.View$PerformClick.run(View.java:25885)
	at android.os.Handler.handleCallback(Handler.java:873)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loop(Looper.java:193)
	at android.app.ActivityThread.main(ActivityThread.java:6669)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

---

[Stypox]

@somos61 thank you for testing, I have no idea why docTree.getUri() would return "downloads", but now I added a catch that ignores all errors.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[somos61]

@somos61 thank you for testing, I have no idea why docTree.getUri() would return "downloads", but now I added a catch that ignores all errors.

dunno why it was 'downloads' instead of 'Download' either, but now dwnl path for SAF is 'content://com.android.providers.downloads.documents/tree/raw:/storage/emulated/0/Download' and downloads ok, for all tested. Thank you