[Fontconfig] Re: Format of cache file are different on 32bit and 64bit system.

[Mike FABIAN]

Patrick Lam <plam at MIT.EDU> さんは書きました:

> Mike FABIAN wrote:
>> Patrick Lam <plam at MIT.EDU> さんは書きました:
>>
>>>Zhe Su wrote:
>>>
>>>>Hi,
>>>>  Recently I found that format of fonts.cache-2 file are different on
>>>>32bit and 64bit system. It leads big performance issue for 32bit
>>>>applications on 32bit/64bit mixed system, like x86_64. Because 32bit
>>>>applications must re-create local cache file on startup, almost every
>>>>time.
>>>>  For more information, see https://bugzilla.novell.com/show_bug.cgi?id=160226
>>>>  Is it possible to unify the cache file format for both 32bit and
>>>>64bit system?
>>>
>>>That bug is not world readable.
>>>
>>>I designed the cache format so that it would contain caches for both
>>>32bit and 64bit systems in the same file.  It may not work; I'll look
>>>into it tomorrow.
>> I think I have fixed it, see also
>>     http://bugzilla.novell.com/show_bug.cgi?id=160226
>
> fc-cache32 would be a fine solution to the dir caches problem, if you
> can generate that binary.
>
> Your patch makes things better but doesn't completely fix the problem
> yet.  I'm looking into it.
>
> The system I'm on here is amd64 with an ia32 chroot.  /home is shared
> between the amd64 install and the chroot.
>
> 1. remove a fonts.cache-2 file (dir cache) from both the install and
> the chroot
> 2. fc-list in the install
> 3. fc-list in the chroot
> 4. fc-cat ~/.fonts.cache-2 in the install
>
> You'll see that the install's .fonts.cache-2 gets trampled by the
> chroot's .fonts.cache-2.

I cannot reproduce this. It works fine for me.  I am running 32bit and
64bit applications using fontconfig alternatetly and they don't
trample each others data in ~/.fonts.cache-2.

> Note also that the line you patched was a fix to 'severe perf
> regression when global fonts.cache-2 files are missing', which you and
> I tested back in October 2005.  I'm going to test that behaviour as
> well (put junk in .fonts.cache-2, see what happens).

If ~/.fonts.cache-2 is "missing", it doesn't have to be deleted.

Deleting it when the current architecture cannot be found
cannot be correct in my opinion.

-- 
Mike FABIAN   <mfabian at suse.de>   http://www.suse.de/~mfabian
睡眠不足はいい仕事の敵だ。