[Fontconfig] Re: Structure of cache files

[James Cloos]

>>>>> "Keith" == Keith Packard <keithp at keithp.com> writes:

Keith> I suggest that allow each configured font directory to be
Keith> mirrored into the /var/cache hierarchy and store the cache
Keith> files there; essentially doing a directory prefix mapping
Keith> (/usr/share/fonts -> /var/cache/fontconfig) and appending
Keith> the rest of the path normally.  This will allow the existing
Keith> naming mechanisms to be used as-is.

Perhaps it should be $FOO -> /var/cache/fontconfig/$FOO so that all
of the various paths can be handled.  At least /usr/local/share/fonts
and /local/share/fonts will get used and should be supported.

I wonder though how much of a performance hit we'll see by abusing
the kernels' filesystem caches by doubling the number if directories
searched each time a fontconfig-linked program starts?

As an example, given a reasonably large number of font directories
(each dist package has its own under /usr/share/fonts, I tend to
keep my ~/.fonts organized like that, etc) and the large number of
libraries most GUI apps link against these days whenever I emerge
anything on my gentoo laptop with X running it takes minutes each
time ldconfig is run versus deciseconds when X is not running.

Keith> If we do this, what would you think about removing the whole
Keith> /var/cache/fontconfig heirarchy when fontconfig was purged?

Probably should happen; even if it is being purged just to make sure a
re-install is clean the user probably wants to regenerate all of the
cache files.  But that should be an issue for the packager rather than
for the developer.

-JimC
-- 
James H. Cloos, Jr. <cloos at jhcloos.com>