a694258457
__git_ps1() is usually added to the prompt inside a command
substitution, imposing the overhead of fork()ing a subshell. Using
__git_ps1() for $PROMPT_COMMAND is slightly faster, because it avoids
that command substitution.
Mention this in the comments about setting up the git prompt.
The whole series speeds up the bash prompt on Windows/MSysGit
considerably. Here are some timing results in three scenarios, each
repeated 10 times:
At the top of the work tree, before:
$ time for i in {0..9} ; do prompt="$(__git_ps1)" ; done
real 0m1.716s
user 0m0.301s
sys 0m0.772s
After:
real 0m0.687s
user 0m0.075s
sys 0m0.396s
After, from $PROMPT_COMMAND:
$ time for i in {0..9} ; do __git_ps1 '\h:\w' '$ ' ; done
real 0m0.546s
user 0m0.075s
sys 0m0.181s
At the top of the work tree, detached head, before:
real 0m2.574s
user 0m0.376s
sys 0m1.207s
After:
real 0m1.139s
user 0m0.151s
sys 0m0.500s
After, from $PROMPT_COMMAND:
real 0m1.030s
user 0m0.245s
sys 0m0.336s
In a subdirectory, during rebase, stash status indicator enabled,
before:
real 0m3.557s
user 0m0.495s
sys 0m1.767s
After:
real 0m0.717s
user 0m0.120s
sys 0m0.300s
After, from $PROMPT_COMMAND:
real 0m0.577s
user 0m0.047s
sys 0m0.258s
On Linux the speedup ratio is comparable to Windows, but overall it
was about an order of magnitude faster to begin with. The last case
from above, repeated 100 times, before:
$ time for i in {0..99} ; do prompt="$(__git_ps1)" ; done
real 0m2.806s
user 0m0.180s
sys 0m0.264s
After:
real 0m0.857s
user 0m0.020s
sys 0m0.028s
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
////////////////////////////////////////////////////////////////
Git - the stupid content tracker
////////////////////////////////////////////////////////////////
"git" can mean anything, depending on your mood.
- random three-letter combination that is pronounceable, and not
actually used by any common UNIX command. The fact that it is a
mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the
dictionary of slang.
- "global information tracker": you're in a good mood, and it actually
works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations
and full access to internals.
Git is an Open Source project covered by the GNU General Public
License version 2 (some parts of it are under different licenses,
compatible with the GPLv2). It was originally written by Linus
Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
See Documentation/gittutorial.txt to get started, then see
Documentation/everyday.txt for a useful minimum set of commands, and
Documentation/git-commandname.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with "man gittutorial" or "git help tutorial", and the
documentation of each command with "man git-commandname" or "git help
commandname".
CVS users may also want to read Documentation/gitcvs-migration.txt
("man gitcvs-migration" or "git help cvs-migration" if git is
installed).
Many Git online resources are accessible from http://git-scm.com/
including full documentation and Git related tools.
The user discussion and development of Git take place on the Git
mailing list -- everyone is welcome to post bug reports, feature
requests, comments and patches to git@vger.kernel.org (read
Documentation/SubmittingPatches for instructions on patch submission).
To subscribe to the list, send an email with just "subscribe git" in
the body to majordomo@vger.kernel.org. The mailing list archives are
available at http://news.gmane.org/gmane.comp.version-control.git/,
http://marc.info/?l=git and other archival sites.
The maintainer frequently sends the "What's cooking" reports that
list the current status of various development topics to the mailing
list. The discussion following them give a good reference for
project status, development direction and remaining tasks.