[cairo] 1.1.6 to 1.2.0 performance

[Dominic Lachowicz]

This is all well and good, but shouldn't it be happening on the
fontconfig list [1], so that we're sure it has Keith Packard's and Pat
Lam's attention? I know that Pat is concerned about performance and
regressions, so bringing this to his attention can only be a good
thing.

-Dom

[1] http://lists.freedesktop.org/mailman/listinfo/fontconfig

On 7/13/06, John Ellson <ellson at research.att.com> wrote:
> James Cloos wrote:
> >>>>>> "David" == David Turner <dturner at nds.com> writes:
> >>>>>>
> >
> > David> How on earth can you get 940 *directories* of fonts. Even the font CDs
> > David> I've seen only
> > David> use a dozen directories, and they're packed with hundreds if not
> > David> thousands of fonts.
> >
> > Many out each family in its own dir, and even if not man users move
> > each family into its own dir when installing, to ease the maintenance
> > headaches if they do not want all font families in the search tree at
> > all times.
> >
> The box is a vanilla Fedora rawhide box as far as fonts are concerned.
> Its possible that the cache
> mess was caused by the evolution through daily updates, but fc-cache
> should clean this up regardless.
>
> As mentioned in previous mail,  rm -f /var/cache/fontconfig/*; fc-cache
> reduces the number from 940 to 168, and a check of the strace output
> indicated that this
> is from about 56 cache files being open()'ed 3 times each.
> > David> I suspect some really horrible thing, like having "/usr/share"
> > David> in the fontconfig search path,
> >
>
> The directory list in  /etc/font/font.conf contains only:
>     /usr/share/fonts
>     /usr/share/X11/fonts/Type1
>    /usr/share/X11/fonts/OTF
>    ~/.fonts
> > OTOH, that is also a distinct possibility.  John, can you check that
> > box for its <dir/> entries?
> >
> > David> but doesn't stat-ing these 940 directories is going to be
> > David> a *lot* faster than memory-mapping the
> > David> cache files that would be within them otherwise ?.
> >
> > David> I'm assuming that not all of them are going to
> > David> change a lot, so a single cache in $HOME could
> > David> be a performance winner.
> >
> > That is a good point.  I suspect you'd loose the ability to run
> > fc-cat(1) to grab info about the fonts in a given dir -- something
> > I got used to using the old, ascii cache files for -- but otherwise
> > it does seem beneficial.
> >
> > -JimC
> >
>
>
> IMO, there needs to be a most-recently-used, per-user cache of
> pattern->fontfile resolution.
> This could be cleared on logout perhaps, or cleared by checking
> timestamps against the /var/cache/fontconfig directory
>
> If I run a utility like dot that opens "Times-Roman" at the same
> fontsize and slant in two consecutive invocations
> I don't see why it should open more that 1 cache file and 1 font file in
> the second and subsequent invocations.
>
> John
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