[sane-devel] Sane Release 1.1.0 ?

[stef]

Le Thursday 06 November 2008 21:43:26 stef, vous avez écrit :
> Le Thursday 06 November 2008 11:01:40 Julien BLACHE, vous avez écrit :
> > stef <stef.dev at free.fr> wrote:
> > > 	to define a way both version can coexist we have to know	what are the
> > > cases which lead to this coexistence on a system. In my -possibly
> > > simplistic- view, since any out of tree backend only needs a mere
> > > recompile to get in sync, I don't see at first where is the problem.
> > > Could you tell me the precise cases you are thinking of ?
> >
> > samsung MFP backend. No sources. No maintainer. No hope for an update
> > anytime soon. Shitload of users.
>
> 	Hello,
>
> 	this is the kind of headache binary only drivers provide. I have a GeForce
> Ti 4200 that I can't use yet on a recent kernel ....
>
> 	However, do you think we could manage to get such backends still working
> by: - installing sane 2 backends in a different directory (dll2.d ?) where
> sane 1 never search for backends
> 	- modify dll.c to search in sane1 directories when given a SANE 1 major,
> and sane 2 directories for SANE 2 major, possibly falling back to sane 1
> directories if no backend is found.
>
>
> Regards,
> 	Stef

	Hello,

	as a proof of concept,  I have made 2 different versions of SANE coexisting 
on my system. First I have installed version 1.0.19 (with the pnm backend 
enabled) with the corresponding xsane. Then i raised the V_MAJOR and 
SANE_CURRENT_MAJOR to 2, compiled and installed it (without the pnm backend). 
I have then modified xscanimage to build against this new version and 
installed it. 
	In my backend development environment, I have created a meta backend which is 
a copy of dll.c, but that searches only backends with a major of 1 and has no 
preloaded backends. I added the meta backend to dll.conf.
	In such a setting, xsane is using SANE 1 backends without any troubles, and 
xscanimage uses SANE2 backends. Furthermore, thanks to the compatibility meta 
backend, xscanimage can still use the SANE1 backends installed on the system 
(in my case I tested it with the pnm backend).
	The only thing left is to make SANE install its files under a sane2 
subdirectory within sane.d so there is no clash on the conf files of both 
versions. But this is an easy thing to do.
	This way, we could provide support for mixed environments and keep SANE 1 
only backends working. Various packages could upgrade at their own pace, and 
no scanner support would be lost.

Regards,
	Stef