marker file
'start mode' if true, 'end mode' if false.
Closes this destination.
Closes this destination. This method should only be called once during the lifetime of a destination, and it should not be called concurrently with other methods of this class.
Opens this destination.
Opens this destination. This method should only be called once during the lifetime of a destination, and it should not be called concurrently with other methods of this class.
Writes quads to this destination.
Writes quads to this destination. Implementing classes should make sure that this method can safely be executed concurrently by multiple threads.
Handles a marker file that signals that the extraction is either running ('start mode') or finished ('end mode').
In 'start mode', the file is created before the extraction starts (it must not already exist) and deleted after the extraction ends.
In 'end mode', the file is deleted before the extraction starts (if it already exists) and re-created after the extraction ends.