[libcamera-devel] [RFC PATCH v3 1/2] libcamera: camera: Take span of StreamRole instead of vector

[Barnabás Pőcze]

Hi


2023. május 18., csütörtök 18:16 keltezéssel, Kieran Bingham <kieran.bingham at ideasonboard.com> írta:

> Quoting Barnabás Pőcze (2023-05-18 16:17:41)
> > Hi
> >
> >
> > 2023. május 16., kedd 1:28 keltezéssel, Kieran Bingham <kieran.bingham at ideasonboard.com> írta:
> >
> > > Quoting Barnabás Pőcze via libcamera-devel (2023-05-10 00:07:57)
> > > > Change the parameter type of `generateConfiguration()` from `const std::vector&`
> > > > to `libcamera::Span`. A span is almost always preferable to a const vector ref
> > > > because it does not force dynamic allocation when none are needed, and it allows
> > > > any contiguous container to be used.
> > >
> > > Sounds like a reasonable move to me.
> > >
> > > >
> > > > A new overload is added that accepts an initializer list so that
> > > >
> > > >   cam->generateConfiguration({ ... })
> > > >
> > > > keeps working.
> > > >
> > > > There is no API break since a span can be constructed from a vector
> > > > and the initializer list overload takes care of the initializer lists,
> > > > but this change causes an ABI break.
> > >
> > > That's fine too. I'd be interested how the abi-compliance-checker
> > > reports this:
> > >
> > >  Creating compatibility report ...
> > >  Binary compatibility: 100%
> > >  Source compatibility: 99.9%
> > >  Total binary compatibility problems: 0, warnings: 0
> > >  Total source compatibility problems: 2, warnings: 0
> > >  Report: compat_reports/libcamera/v0.0.5_to_v0.0.5-22-g5c94fbcc9d05/compat_report.html
> > >
> > > Well - at least it noticed something ;-)
> >
> > Unfortunately I think that is incorrect. This is definitely an ABI break.
> > (And as far as I can tell not an API break.)
> >
> 
> Hrm... a little worrying for the abi-compliance-checker then...

Well, to be fair, it *is* an API break as well, but very unlikely to be
noticed by anyone. I don't know why it does not notice the ABI break,
the mangled names are completely different...


> [...]


Regards,
Barnabás Pőcze