CrashOnWrite prevents further writing to any state.

Init initializes the VFS.

MoveAwayState renames a detected-to-be-broken state file so it will not be used again.

ReadDir lists all files in a directory.

ReadState loads the given state file and returns its contents.

SetFilesDir does nothing (on Android it'd be used to notify the Go code where to store its data).

WriteState writes the given state file.

ReadSeekCloser is a typical file interface.