[Fontconfig] [patch]: mmapping FontConfig data structures

[Patrick Lam]

Keith Packard wrote:
> I haven't looked at the patch in detail, so some of these questions
> may actually make incorrect assumptions.
> 
>  1)	What happens if you can't mmap the cache files at the 
> 	necessary address?

If a mmap doesn't go through (or it can't find the file), fontconfig
reverts to its default behaviour of loading the files directly.

>  2)	Different users have different sets of font
> 	directories. Does this patch support that?

The patch currently creates one mmap file per user, depending on the
user's configuration.  I've just tested this, and it works here.

>  3)	What about the new <selectfont> elements? These may
> 	also vary for different users.

I don't know anything about <selectfont>, but since everything is on a
per-user basis, I don't see any problems.

It might be worthwhile to split the mmapped cache into a system-global
part and a per-user part; it shouldn't even be very hard.  But I think
that even if we have to have one mmapped cache per user, it's still a
win over the current status.

pat