[sane-devel] scanimage frontend

[James Ring]

On Tue, Apr 26, 2022 at 2:24 PM Povilas Kanapickas <povilas at radix.lt> wrote:
>
> Hi,
>
> On 2022-04-26 17:11, James Ring wrote:
> > Hi all,
> >
> > Would there be any objection if I did some work on tidying up the
> > scanimage frontend implementation? Currently, there are some deeply
> > nested parts of the scanning code interspersed with ifdefs that make
> > it pretty hard to follow.
>
> Agreed, any such improvements are welcome.
>
> > More controversial question, what about writing some parts of it in
> > C++? Applied judiciously, it could make the code easier to maintain.
> > My plan would be to use a small subset of C++ (no exceptions, for
> > example).
>
> That would be great.
>
> I suggest to start with the C++ migration first, because it's easy to
> introduce leaks and similar problems when refactoring C code.
>
> Also, I suggest to split the changes into as many commits as reasonably
> possible.  Large refactoring is likely to introduce regressions. When
> there are many commits it's possible to quickly bisect the problem.
> Having 10 line change in front of the eyes and knowledge that the source
> of the problem is exactly there makes it much easier to quickly address
> issues.

Thank you both for the enthusiasm. My plan would be to first add some
regression tests to minimize the chance that I break existing users,
then start working on the actual frontend code.

I found small things, like introducing RAII to auto-sane-close()
device handles, very handy.

I'm sensitive to how many platforms SANE tries to support, so I will
use vanilla C++ as much as possible and not introduce external
dependencies.

> Cheers,
> Povilas

Thanks,
James