From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 17 Aug 2012 17:40:35 GMT
Subject: Re: [PATCH v2] rev-list docs: clarify --topo-order description
Message-ID: <7vk3wxv2lo.fsf@alter.siamese.dyndns.org>
In-Reply-To: <874no1hnfg.fsf@thomas.inf.ethz.ch>

Thomas Rast <trast@inf.ethz.ch> writes:

> I hope I got that right.  The order of commits is still entirely
> determined by the choice of "any tentative source", but the algorithm
> should now stream nicely once the generation numbers are known.

Thanks for an intereseting read.

Even though generation numbers are not always a good subsitute for
timestamps depending on the use (see the other message), the algorithm
to compute "topo-order" can take advantage of the generation numbers
when they are available, as you illustrated in your message.

We may want to think about adding a new field to the commit object,
with a fallback mechanism to an external "cache" that is generated
on-demand.

Once the mechanism is in place so that any caller of parse_commit()
can depend on having a reliable .generation field in the commit
object it receives from the function, we can start updating various
traversal algorithms to take advantage of this new information.