From: Paul Mackerras <paulus@samba.org>
Date: Sat, 01 Jul 2006 10:35:52 GMT
Subject: Re: [RFC] gitweb wishlist and TODO list
Message-ID: <17574.20488.149073.587594@cargo.ozlabs.ibm.com>
In-Reply-To: <46a038f90606201417k71c4c43ak59204774bcfe8246@mail.gmail.com>

Martin Langhoff writes:

> > If I remember correctly, it was done in the background, and it was done
> > at least partially _in_ gitk (Tcl/Tk).
> 
> I suspect it is doing a whole lot of git-merge-base invocations, which
> are rather costly. I don't know of any cheaper way to ask that
> question.

There's no git-merge-base involved.  Gitk does a

git-rev-list --all --topo-order --parents

and reads the output of that, and then traverses the entire graph
forwards and backwards (in Tcl).  (This is after gitk has read the
output of git ls-remote $GIT_DIR, so it knows which commits have
tags.)

Paul.