Shawn Pearce <spearce@xxxxxxxxxxx> wrote:
> Junio C Hamano <junkio@xxxxxxx> wrote:
> >
> > Also I wonder how much complexity would we suffer and how much
> > efficiency would we gain if we binary search the logdata (the
> > committer info is variable length, so you would need to resync
> > in each step).
>
> I thought about doing this but did not think it would be worth the
> effort (either developer to code or CPU to execute) at this point
> in time. I don't think users will be pulling refs from the log very
> often and if they are they will probably be pulling from recent time,
> not very far back. Thus starting at the end and walking back is
> probably "good enough".
>
> But if it proves to be too slow in practice I'm sure I can come up
> with a faster way to walk through the log. :-)
I just ran a test on my PowerBook: walking a 10,000 line log file and
extracting the very oldest commit along. Each hit on git-rev-parse
seems to took about 100 ms. Hardly worth worrying about for casual
use. Further git-rev-parse is taking 73 ms just to run '--verify
HEAD' so an extra 30 ms to read the 10k log is pretty much nothing.
[spearce@pb15 trash]$ wc -l .git/logs/refs/heads/master
10000 .git/logs/refs/heads/master
[spearce@pb15 trash]$ head -n 1 .git/logs/refs/heads/master
b943559a305bdd6bdee2cef6e5df2413c3d30a00 0000000000000000000000000000000000000000 A U Thor <example@xxxxxxxxxxx> 1136091600 -0500
[spearce@pb15 trash]$ perl -e 'print scalar(localtime shift),"\n"' 1136091600
Sun Jan 1 00:00:00 2006
[spearce@pb15 trash]$ time ../../git-rev-parse --verify HEAD@'300 days'
warning: Log .git/logs/refs/heads/master only goes back to Thu, 1 Jan 1970 00:00:00 +0000.
b943559a305bdd6bdee2cef6e5df2413c3d30a00
real 0m0.112s
user 0m0.029s
sys 0m0.023s
[spearce@pb15 trash]$ time ../../git-rev-parse --verify HEAD@'300 days'
warning: Log .git/logs/refs/heads/master only goes back to Thu, 1 Jan 1970 00:00:00 +0000.
b943559a305bdd6bdee2cef6e5df2413c3d30a00
real 0m0.105s
user 0m0.029s
sys 0m0.023s
--
Shawn.
-
: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html