[Fontconfig] Application startup performance

[Akira TAGOH]

On Wed, Jan 13, 2016 at 12:52 AM,  <u-pnrz at aetey.se> wrote:
> On Tue, Jan 12, 2016 at 07:29:44AM -0800, Keith Packard wrote:
>> > I would be even more uncomfortable if there will be some locks involved
>> > or some daemons would be expected to run just to be able to rely on
>> > fontconfig. Explicit cache creation looks like the cleanest solution.
>>
>> Here's another alternative -- cache creation could be the responsibility
>> of fc-cache, but perhaps applications could validate the cache by
>> checking directory timestamps and loading directories which were out of
>> date manually (as they do today) but *not* write out that information
>
> I would prefer them to skip such directories instead.

That may introduces a strange problem on a running application when
fonts is updated if any libraries at the higher layers sets non-zero
to FcConfigSetRescanInterval(). so if the updates occurs when reading
caches from applications, we can't avoid I/O operation in fontconfig
to build a cache. otherwise they can't use such fonts from
applications right.

dunno if we want to get rid of the cache generation from the runtime,
we may need a dedicated font installlation program to build a cache
before putting a font into a directory.

-- 
Akira TAGOH