Re: simple cvs-like git wrapper

From: Shawn O. Pearce <spearce@spearce.org>
Date: Jan 31, 2008, 06:01 UTC
Message-ID: <20080131060136.GZ24004@spearce.org>
In-Reply-To: <20080131054124.GG9612@venus>

"Ed S. Peschko" <esp5@pge.com> wrote:

Show 12 quoted lines

> > This is going to be slow as you are running git-merge for each
> > and every branch available to you.  You can do a lot better by
> > loading the branch DAG into memory in Perl/C/Python and doing a
> > graph coloring algorithm to see if a merge is necessary or not,
> > as if you are merging everything all of the time almost everything
> > is going to be always merged to everything else.  Which as I said
> > earlier is nuts.
> 
> hmm. Is there a simple method to get this graph? I'm assuming that you
> would have to get all the local commits and compare them to the remote
> commits, and only merge the branches that have commits not yet 
> merged..

Something along these lines:

	%remotes = \
		git for-each-ref \
		--format='%(objname) %(refname)' \
		refs/remotes/origin;

	@lines = \
		git rev-list \
		keys %remotes \
		--not HEAD

	foreach $line in @lines {
		if $remotes contains $line
			git merge $remotes{$line}
	}

That gets you the graph. The %(objname) string coming back from for-each-ref is in $line in the loop. If you see $line inside that map you built from for-each-ref then that commit isn't yet in the current branch. So you'd then want to merge that commit.

-- 
Shawn.