Re: [RFC/PATCH 1/5] gettext: fix bug in git-sh-i18n's eval_gettext() by using envsubst(1)

From: Johannes Sixt <j.sixt@viscovery.net>
Date: Nov 9, 2010, 10:36 UTC
Message-ID: <4CD9241F.6070807@viscovery.net>
In-Reply-To: <AANLkTi=23MXbZeBF=eJLRnQycx4Bdg_an2aa_3oGWR66@mail.gmail.com>

Am 11/9/2010 10:49, schrieb Ævar Arnfjörð Bjarmason:

Show 12 quoted lines

> On Tue, Nov 9, 2010 at 10:47, Johannes Sixt <j.sixt@viscovery.net> wrote:
>> Am 11/9/2010 10:35, schrieb Ævar Arnfjörð Bjarmason:
>>> Why is that a "*must*"?
>> ...
>>> But maybe you have reason to think otherwise? I haven't noticed any
>>> noticable slowdowns from doing it this way, but maybe I've been
>>> looking at the wrong thing.
>>
>> You didn't do your timings in Windows, did you? Every fork() that you can
>> avoid is a win.
> 
> What's the result of timing it on Windows?

I do not have gettext, hence, I test 'git version' as a reference:

$ time (for i in {1..100}; do git version; done) > /dev/null

real 0m5.610s user 0m1.707s sys 0m0.712s

Then I tested this function. It is not exactly the same that you tested, but it has the same number of subshells and builtin and external command invocations:

eval_gettext ()
{
    gettext "$1" |
    ( : `git-sh-i18n--envsubst <<< "$1"`
      git-sh-i18n--envsubst <<< "$1"
    )
}

$ time (for i in {1..100}; do eval_gettext foobar; done) > /dev/null

real 0m20.578s user 0m8.457s sys 0m3.915s

Note that there are only 100 iterations, so we are talking about 0.2 seconds per eval_gettext call! That's an awful lot of time even for a single error message.

-- Hannes