On Jun 3, 2007, at 6:11 AM, Simon Hausmann wrote:
On the topic of git integration with perforce, what are the chances
of getting
git-p4 ( http://repo.or.cz/w/fast-export.git ) into git's contrib/
fast-export
area? :)
git-p4 can do everything git-p4import can do plus a lot more (it
can track
multiple branches, it's a hell of a lot faster, it can export back
to p4 and
it also works on Windows!).
I missed that one...I just saw Tailor and the Perl script someone
else had written.
Ergh. git-p4 imports both "subprocess" and "popen2" and also uses
"system" and "os.popen". Why use four different modules to launch git
and p4?
The branch support's interesting. Have you considered tracking
integration history? I was pondering it and am not sure if it's
feasible. Perforce doesn't seem to have an efficient way of
displaying it (just "p4 integrates" that will fetch *all* revisions
even if you want incremental results and "p4 filelog" which would
have to be done on each file). Also, I think there's some mismatch
between the Perforce and git models.
git-p4import.py should work fine on Windows, too - the binary mode on
the pipe should be all handled by "subprocess", and git-p4's
data.replace("\r\n", "\n") is not necessary if you use "LineEnd:
unix" or "share" in the Perforce client specification.
As for performance...hmm. Looks like git-p4import.py runs these
commands for each Perforce revision:
realtime operation
3.4% p4 describe -s N
66.6% p4 sync ...@N
[*] 10.2% git ls-files -m -d -o -z | git update-index --add --
remove -z --stdin
2.6% git rev-parse --verify HEAD
4.2% git write-tree
2.8% git commit-tree xxxxxx
7.5% git tag -f p4/N xxxxxx
2.7% git update-ref HEAD xxxxxx
That's with Perforce running over the network. Are you running locally?
git-p4 seems to use "git fast-import". I guess the big performance
improvement there is removing the ls-files operation? So we're
talking about a 0-10% speedup, right? Plus some fork()/exec() overhead.
[*] - Note that I just discovered a big performance regression in my
patches. Reading the ls-files into Python, through a regexp, and back
out through update-index was a horrible idea. The times above are
with that fixed.
--
Scott Lamb <http://www.slamb.org/>
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