[sane-devel] backend integration
Matto Marjanovic
maddog at mir.com
Sun Sep 1 21:45:08 BST 2002
>> Hmm... and the more I look at this, the less I understand what the
>> SANE_STATUS_INVAL case is for. (The microtek backend is blocking-mode
>> exclusively, so I've never really dealt with this....) What does
>> "image acquistion is pending" mean? Is that before or after sane_start()
>> has been called?
>
>sane_set_io_mode must be used after sane_start (and before sane_cancel).
It doesn't seem very intuitive to me, but as long as that is the way it is,
that should also be explicitly stated in Section 4.3.12 (the description
of sane_set_io_mode()).
Is the SANE-2 draft online anywhere? I don't see any link to it on the
SANE website. I just got the crazy idea that maybe all of the blocking/
non-blocking IO mode stuff should be removed from the next version of
the standard. It seems a bit silly and bloated to have so many backends
re-implementing the same functionality of forking a process to decouple
their I/O, when it could be written once in the frontend -- especially
since there are so many more backends than frontends. This would also
allow the frontend author to do a much better job of optimizing the flow
and/or memory useage, since she knows exactly where she wants the data
to go, and can avoid an extra trip through a pipe, etc.
Just an idea...
-matt m.
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