Re: [Libexif-devel] Error handling

[Jan P. <pa...@pi...>]

Hi,

thanks for your contribution to the discussion - I hope more & more
people will join us. LibExif is small library although quite complex.
I'd like to avoid blowing it up with complicated stacks or tables of
error handlers.

 -- Jan

>> Let's say we define EXIF_RESULT_OK, EXIF_RESULT_SOMEWHAT_OK and
>> EXIF_RESULT_NOT_OK. What code should libexif return if it encounters
>> an unknown tag or a wrong format on loading?
>
> I don't intend to suggest making things complex, but two options pop to
> mind that would clarify this:
>
> (1) Error handlers.
>
> Make an exif_set_handler(int error, void (*handler)(int err, char
> *msg)) or the like (my definition is just for example). Keep a table of
> error handlers. Set the default handler for every error to be the
> logging function currently in use. This makes EXIF_RESULT_SOMEWHAT_OK
> disambiguous, because by that point a developer will know what has
> happened, and it maintains compatibility with the current API, because
> by default, everything is still logged with the log handler.
>
> (2) Error stack.
>
> Make a simple struct that defines an error condition, and return a
> pointer to a stack of them. Yes, this means memory allocation, but it
> leaves it up to the developer as to what to do with it. Then it's just =
a
> matter of exif_errstack_cleanup(errstack *). This, however, leaves the
> current logging routines in an awkward limbo, where developers may
> develop around the stack, forget logging, and then, sometime down the
> road, someone will push for removing it from the API, because
> developers can already log things based on the error stack.
>
>
> I think that (1) is probably the best approach as (2) is horribly
> ugly, but I'm just throwing ideas out there. Let me know if I'm
> horribly off base.
>
> -- Mike "Dexter" Church
>
>
> -------------------------------------------------------
> SF email is sponsored by - The IT Product Guide
> Read honest & candid reviews on hundreds of IT Products from real users=
.
> Discover which products truly live up to the hype. Start reading now.
> http://ads.osdn.com/?ad_id=3D6595&alloc_id=3D14396&op=3Dclick
> _______________________________________________
> Libexif-devel mailing list
> Lib...@li...
> https://lists.sourceforge.net/lists/listinfo/libexif-devel