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

From
SZEDER Gábor <szeder@ira.uka.de>
Date
May 25, 2012, 07:35 UTC
Message-ID
<20120525073506.GD2052@goldbirke>
In-Reply-To
<CAOnadRFbrhrFz7Ya3Vhgsju9G723Qu0OdJnM31xFmBqQNgj6gA@mail.gmail.com>
On Thu, May 24, 2012 at 11:36:45PM -0400, Ted Pavlic wrote:
Show 6 quoted lines
> > 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

Previous: Junio C HamanoNext: Thomas Rast
Message 31 of 34 in “completion: split into git-prompt.sh”
  1. 0/2 completion: split into git-prompt.shFelipe Contreras, May 22, 2012
  2. 1/2 completion: remove executable modeFelipe Contreras, May 22, 2012
  3. 2/2 completion: split __git_ps1 into a separate scriptFelipe Contreras, May 22, 2012
  4. Zbigniew Jędrzejewski-SzmekMay 22, 2012
  5. Ted PavlicMay 22, 2012
  6. Felipe ContrerasMay 23, 2012
  7. Felipe ContrerasMay 23, 2012
  8. Junio C HamanoMay 23, 2012
  9. Felipe ContrerasMay 23, 2012
  10. Junio C HamanoMay 23, 2012
  11. Ted PavlicMay 23, 2012
  12. Felipe ContrerasMay 23, 2012
  13. Ted PavlicMay 23, 2012
  14. SZEDER GáborMay 24, 2012
  15. SZEDER GáborMay 24, 2012
  16. Ted PavlicMay 22, 2012
  17. Felipe ContrerasMay 23, 2012
  18. Junio C HamanoMay 23, 2012
  19. SZEDER GáborMay 24, 2012
  20. Ville SkyttäMay 25, 2012
  21. Where should git-prompt.sh be installed?Jonathan Nieder, Oct 25, 2012
  22. Drew NorthupOct 25, 2012
  23. Danny YatesOct 25, 2012
  24. __git_ps1: migrate out of contrib/completionJonathan Nieder, Oct 25, 2012
  25. Felipe ContrerasOct 25, 2012
  26. Todd ZullingerNov 8, 2012
  27. Anders KaseorgOct 25, 2012
  28. SZEDER GáborOct 25, 2012
  29. Jonathan NiederOct 25, 2012
  30. Junio C HamanoMay 23, 2012
  31. SZEDER GáborMay 25, 2012
  32. Thomas RastMay 25, 2012
  33. Felipe ContrerasMay 25, 2012
  34. Junio C HamanoMay 25, 2012

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