[Fontconfig] Application startup performance

[u-pnrz at aetey.se]

On Sun, Jan 17, 2016 at 11:35:50AM +0100, Raimund Steger wrote:
> On Thu, 14 Jan 2016 16:18:18 +0100
> u-pnrz at aetey.se wrote:
> > It would be useful to have references which software and when tries
> > to update the fonts, without knowing to run fc-cache.
> > 
> > Would you name some examples?
> 
> all Win32 apps I know (VLC, mplayer, probably Inkscape, etc.). Not
> because *they* install fonts but because on Windows running fc-cache
> is uncommon.

Most of those applications have presumably some kind of installers which
are in a very good position to run fc-cache, as soon as the developers
become aware of the need.

It is also faster / more efficient to build the cache once and skip the
checking at every run, than racefully check (and possibly build) every
time. Thus an advance cache build makes in the end the users happier.

> Anyway. If it's mostly the Red Hat package tool that exposes these
> races, it should be a lot more realistic to change that and go back to
> mtime checking, instead of educating all users currently out there.

Education of the users is easier if the behaviour of the library becomes
more predictable, without hidden updates of vital data.

(It is commercial parties who have a distinct interest in keeping the user
clueless and dependent, free softwares have better odds for cooperating
with the users :)

Thanks for the discussion! Fontconfig is very useful,
looking forward to fixes making it even better than today.

Regards,
Rune