Bug 11573

Summary:

[PATCH libXfont] rescan catalogue:<dir> fontpaths on directory changes

Product:

xorg

Reporter:

Ademar Reis <ademar>

Component:

Lib/Xfont

Assignee:

Kristian Høgsberg <krh>

Status:

RESOLVED WORKSFORME

QA Contact:

Xorg Project Team <xorg-team>

Severity:

normal

Priority:

medium

Keywords:

patch

Version:

git

Hardware:

Other

OS:

All

Whiteboard:

i915 platform:

i915 features:

Attachments:

Description	Flags
rescan catalogue:<dir> fontpaths on directory changes (b0rken)	none
rescan catalogue:<dir> fontpaths on directory changes	none

Description Ademar Reis 2007-07-12 10:54:46 UTC

From an e-mail sent to xorg-ml a couple of days ago:

The current catalogue:<dir> implementation on libXfont rescan the
font paths only if <dir> (fontpath.d) has its mtime changed.

The problem is that most of the time, what changes is not the
fontpath.d dir, but the dirs pointed by the symlinks (e.g. some
fonts are installed inside the same directory, package managers
write the symlink before the directory is changed, user can run
mkfontdir, etc).

I'm not familiar enough with libXfont to implement an optimal
solution, so I cooked a simple and non-intrusive patch that does
the work by forcing a rescan in case any of the dirs have its
mtime changed (below, applies on top of my previous libXfont
patches).

My solution is not optimal since it runs through the fontpath.d
dir twice (once to check mtime and once to build the FPEs), but
it works and accoding to my tests the performance cost is far
from being noticeable.

So, what do you think? Any chances of merging such a patch?

(this patch applies on top of the one from bug #11572)

Comment 1 Ademar Reis 2007-07-12 10:55:45 UTC

Created attachment 10702 [details] [review]
rescan catalogue:<dir> fontpaths on directory changes (b0rken)

Comment 2 Ademar Reis 2007-07-13 15:40:45 UTC

Comment on attachment 10702 [details] [review]
rescan catalogue:<dir> fontpaths on directory changes (b0rken)

this patch is broken, there's a duplicated closedir() call at the end. I'll attach a new one.

Comment 3 Ademar Reis 2007-07-13 15:41:52 UTC

Created attachment 10717 [details] [review]
rescan catalogue:<dir> fontpaths on directory changes

Comment 4 Kristian Høgsberg 2007-07-30 11:42:28 UTC

I'd like to keep the fontpath.d code simple and I don't think we should worry to much about the corner cases, since you can always just fall back and issue a

  xset fp rehash

Also, for packaging, you can always just force the symlink, even though it's already there, which will bump the mtime on the fontpath.d dir.

Sounds ok?

Comment 5 Ademar Reis 2007-07-30 12:01:33 UTC

The only problem is that it's not intuitive to touch fontpath.d/ to force a rehash (restarting xfs was) and users got used to the non need of running xset fp rehash.

When packaging, we're subject to a race (a package may, for example, add the symlink as the package payload (%files) and run mkfontdir in %post). Or users may add the symlink manually and run mkfontdir later, etc.

But the current code is not elegant (I don't like the double loop) and I guess a more beautiful solution would add considerable complexity. Ultimately it's your call... That's why I submmited the patch as a RFC. :-)

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