Re: [PATCH] fast-export: ensure we traverse commits in topological order

From: Jeff King <peff@peff.net>
Date: Feb 11, 2009, 13:56 UTC
Message-ID: <20090211135640.GA19600@coredump.intra.peff.net>
In-Reply-To: <e2b179460902110248m8055b3amdebcfc550438cff2@mail.gmail.com>

On Wed, Feb 11, 2009 at 10:48:18AM +0000, Mike Ralphson wrote:

Show 8 quoted lines

> > On Tue, 10 Feb 2009, newren@gmail.com wrote:
> > fast-export will only list as parents those commits which have already
> > been traversed (making it appear as if merges have been squashed if not
> > all parents have been traversed).  To avoid this silent squashing of
> > merge commits, we request commits in topological order.
> 
> Any comparative timings? We don't need to rename this to 'git
> reasonably-speedy-export'? 8-)

Hmm.

In git.git:

  $ time git fast-export --all --signed-tags=strip >/dev/null
  real    1m6.013s
  user    1m3.840s
  sys     0m2.140s

  $ time git fast-export --all --signed-tags=strip --topo-order >/dev/null
  real    0m49.018s
  user    0m47.987s
  sys     0m0.888s

I certainly didn't expect it to be _faster_. More efficient use of the delta cache, maybe?

-Peff