[fprint] libfprint and nodejs/node-red

[Thilo Cestonaro]

Hey there!

I'm trying to create nodejs support for libfprint and integrating it
into node-red. For the integration into node-red, unblocking calls are
very important, as it is based on an event queue.

So far I can do enrollment, verifying and identifying via node-red but
with blocking calls in the nodejs backend.
Of course I could simply create my own threads and unblock the calls via
theses, but I read in the docu of libfprint, that
async calls will be implemented and I found the fp_async_enroll_start
a.s.o. stuff.

Is it just, that the docu is not up to date or are theses functions not
yet for use?

I already tried to use fp_async_enroll_start. After a call to it, the
reader reacted (it has a led which shows that it is active), but after a
swipe the callback wasn't called.
I also tried to have regular fp_handle_events call but nothing happens.

What is the current recommendation? Have my own threads, or use the
async stuff from libfprint?
If the async stuff is already for use, how is it supposed to be used?

Thanks!

Regards,
Thilo