Re: [PATCH] Additional merge-base tests

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Jul 4, 2006, 08:23 UTC
Message-ID: <Pine.LNX.4.63.0607041019580.29667@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <7vpsgllsnp.fsf@assigned-by-dhcp.cox.net>

Hi,

On Tue, 4 Jul 2006, Junio C Hamano wrote:

Show 16 quoted lines

> A Large Angry SCM <gitzilla@gmail.com> writes:
> 
> >> This is a good demonstration that merge-base may not give you
> >> minimal set for pathological cases.  If you want to be through
> >> you could traverse everything to make sure we do not say 'S' is
> >> relevant, but that is quite expensive, so I think there will
> >> always be artifacts of horizon effect like this no matter how
> >> you try to catch it (didn't I keep saying that already?).
> >
> > The problem is in mark_reachable_commits(); it is either superfluous
> > or it needs to parse_commit() those commits that haven't been parsed
> > yet that it needs to traverse.
> 
> Yes, you could traverse everything.  But that is not practical.
> We have known that the clean-up pass has this horizon effect,
> and it is a compromise.

We could introduce a time.maximumSkew variable, and just walk only that much further when traversing the commits.

So, if you do not trust your clients to have a proper ntp setup, just say "I trust my peers to be off at most 1 day". That would save lots vs traverse-everything.

Ciao, Dscho