Subject: Re: [PATCH 2/2] completion: split __git_ps1 into a separate script

From: SZEDER Gábor <[email-masked]>
Date: Fri, 25 May 2012 09:35:06 +0200

On Thu, May 24, 2012 at 11:36:45PM -0400, Ted Pavlic wrote:
> > You mean a real git command, which does the same as __gitdir()?  I
> > don't like that, because it will always require 2 fork()s and an
> > exec() and would be slow on Windows.
> 
> Interesting. I guess I didn't realize bash completion was an issue for most
> Windows users. Is it?

It is.  Emulating fork() and exec() is very expensive, so every
subshell, external command, or especially git command in a command
substitution costs dearly.  And the completion script uses many git
commands and even more subshells.

Case in point is __git_ps1() and __gitdir().  There are scenarios
where displaying the git-specific bash prompt takes more than 400ms on
Windows, while displaying the same prompt takes only about 26ms on
Linux on the same hardware.

  http://thread.gmane.org/gmane.comp.version-control.git/197432

Best,
Gábor