[fprint] libfprint and nodejs/node-red

[Vasily Khoruzhick]

Hi Thilo,

On Tue, Nov 3, 2015 at 10:01 PM, Thilo Cestonaro <thilo at cestona.ro> wrote:
> 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?

Docs aren't up to date. And I'd recommend using fprintd instead of
libfprint, that's a proper way of sharing fingerprint scanner between
applications.

> 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?

See fprintd sources, e.g.
http://cgit.freedesktop.org/libfprint/fprintd/tree/src/device.c

> Thanks!
>
> Regards,
> Thilo

Regards,
Vasily