* git vs hg commit counts?
@ 2009-10-27 0:08 Joe Perches
2009-10-27 0:18 ` Junio C Hamano
2009-10-27 1:14 ` Jakub Narebski
0 siblings, 2 replies; 6+ messages in thread
From: Joe Perches @ 2009-10-27 0:08 UTC (permalink / raw)
To: LKML; +Cc: git, mercurial, Marti Raudsepp
I'm comparing linux-kernel git vs hg repositories.
While testing some changes to scripts/get_maintainer.pl,
I noticed that git and hg have different commit counts
for the same files.
For instance:
$ git log --since=1-year-ago -- MAINTAINERS | \
grep -P "^commit [0-9a-f]{40,40}$" | wc -l
514
$ hg log --template="commit {node}\n" --date -365 -- MAINTAINERS | \
grep -P "^commit [0-9a-f]{40,40}$" | wc -l
601
Anyone have any understanding why?
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: git vs hg commit counts?
2009-10-27 0:08 git vs hg commit counts? Joe Perches
@ 2009-10-27 0:18 ` Junio C Hamano
2009-10-27 0:23 ` Joe Perches
2009-10-27 1:16 ` Marti Raudsepp
2009-10-27 1:14 ` Jakub Narebski
1 sibling, 2 replies; 6+ messages in thread
From: Junio C Hamano @ 2009-10-27 0:18 UTC (permalink / raw)
To: Joe Perches; +Cc: LKML, git, mercurial, Marti Raudsepp
Joe Perches <joe@perches.com> writes:
> I'm comparing linux-kernel git vs hg repositories.
>
> While testing some changes to scripts/get_maintainer.pl,
> I noticed that git and hg have different commit counts
> for the same files.
>
> For instance:
>
> $ git log --since=1-year-ago -- MAINTAINERS | \
> grep -P "^commit [0-9a-f]{40,40}$" | wc -l
> 514
>
> $ hg log --template="commit {node}\n" --date -365 -- MAINTAINERS | \
> grep -P "^commit [0-9a-f]{40,40}$" | wc -l
> 601
>
> Anyone have any understanding why?
We simplify a merge history by discarding one branch when the merge result
matches one of the parents. Does "hg" know how to do that as well?
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: git vs hg commit counts?
2009-10-27 0:18 ` Junio C Hamano
@ 2009-10-27 0:23 ` Joe Perches
2009-10-27 1:16 ` Marti Raudsepp
1 sibling, 0 replies; 6+ messages in thread
From: Joe Perches @ 2009-10-27 0:23 UTC (permalink / raw)
To: Junio C Hamano; +Cc: LKML, git, mercurial, Marti Raudsepp
On Mon, 2009-10-26 at 17:18 -0700, Junio C Hamano wrote:
> > $ git log --since=1-year-ago -- MAINTAINERS | \
> > grep -P "^commit [0-9a-f]{40,40}$" | wc -l
> > 514
> > $ hg log --template="commit {node}\n" --date -365 -- MAINTAINERS | \
> > grep -P "^commit [0-9a-f]{40,40}$" | wc -l
> > 601
> > Anyone have any understanding why?
> We simplify a merge history by discarding one branch when the merge result
> matches one of the parents.
Thanks Junio.
> Does "hg" know how to do that as well?
I don't know.
I was hoping to get equivalent results though.
Anyone know how?
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: git vs hg commit counts?
2009-10-27 0:18 ` Junio C Hamano
2009-10-27 0:23 ` Joe Perches
@ 2009-10-27 1:16 ` Marti Raudsepp
2009-10-27 4:14 ` Joe Perches
1 sibling, 1 reply; 6+ messages in thread
From: Marti Raudsepp @ 2009-10-27 1:16 UTC (permalink / raw)
To: Junio C Hamano; +Cc: Joe Perches, LKML, git, mercurial
On Tue, Oct 27, 2009 at 2:18 AM, Junio C Hamano <gitster@pobox.com> wrote:
> We simplify a merge history by discarding one branch when the merge result
> matches one of the parents. Does "hg" know how to do that as well?
57 of the differing changesets are normal merges (probably what Junio explained)
3 are duplicate changesets in hg, probably also related to that
27 changesets are octopus merge fixups
wrt octopus merges: in git, one merge commit can have an arbitrary
number of parents, but in hg a merge changeset always has 2 parents --
so a octopus merge is represented as multiple distinct changesets.
Marti
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: git vs hg commit counts?
2009-10-27 1:16 ` Marti Raudsepp
@ 2009-10-27 4:14 ` Joe Perches
0 siblings, 0 replies; 6+ messages in thread
From: Joe Perches @ 2009-10-27 4:14 UTC (permalink / raw)
To: Marti Raudsepp; +Cc: Junio C Hamano, LKML, git, mercurial
On Tue, 2009-10-27 at 03:16 +0200, Marti Raudsepp wrote:
> On Tue, Oct 27, 2009 at 2:18 AM, Junio C Hamano <gitster@pobox.com> wrote:
> > We simplify a merge history by discarding one branch when the merge result
> > matches one of the parents. Does "hg" know how to do that as well?
>
> 57 of the differing changesets are normal merges (probably what Junio explained)
> 3 are duplicate changesets in hg, probably also related to that
> 27 changesets are octopus merge fixups
>
> wrt octopus merges: in git, one merge commit can have an arbitrary
> number of parents, but in hg a merge changeset always has 2 parents --
> so a octopus merge is represented as multiple distinct changesets.
Thanks.
For hg support in get_maintainers, it's probably
simplest to ignore the delta in number of commits
as "close enough".
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: git vs hg commit counts?
2009-10-27 0:08 git vs hg commit counts? Joe Perches
2009-10-27 0:18 ` Junio C Hamano
@ 2009-10-27 1:14 ` Jakub Narebski
1 sibling, 0 replies; 6+ messages in thread
From: Jakub Narebski @ 2009-10-27 1:14 UTC (permalink / raw)
To: Joe Perches; +Cc: LKML, git, mercurial, Marti Raudsepp
Joe Perches <joe@perches.com> writes:
> I'm comparing linux-kernel git vs hg repositories.
>
> While testing some changes to scripts/get_maintainer.pl,
> I noticed that git and hg have different commit counts
> for the same files.
>
> For instance:
>
> $ git log --since=1-year-ago -- MAINTAINERS | \
> grep -P "^commit [0-9a-f]{40,40}$" | wc -l
> 514
>
> $ hg log --template="commit {node}\n" --date -365 -- MAINTAINERS | \
> grep -P "^commit [0-9a-f]{40,40}$" | wc -l
> 601
>
> Anyone have any understanding why?
It *might* be caused by the fact that in Mercurial commit can have
only up to two parents. This means that octopus merges (merge commits
with more than two parents: there are a few of them in linux-kernel
history) have to be represented as a set of two-parent merges.
--
Jakub Narebski
http://stackoverflow.com/questions/1598759/git-and-mercurial-compare-and-contrast/1599930#1599930
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-10-27 4:14 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2009-10-27 0:08 git vs hg commit counts? Joe Perches
2009-10-27 0:18 ` Junio C Hamano
2009-10-27 0:23 ` Joe Perches
2009-10-27 1:16 ` Marti Raudsepp
2009-10-27 4:14 ` Joe Perches
2009-10-27 1:14 ` Jakub Narebski
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