Re: Git and GCC

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 6, 2007, 20:04 UTC
Message-ID: <7vk5nrd1yq.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <1196968371.18340.30.camel@ld0161-tx32>

Jon Loeliger <jdl@freescale.com> writes:

Show 10 quoted lines

> On Thu, 2007-12-06 at 00:09, Linus Torvalds wrote:
>
>> Git also does delta-chains, but it does them a lot more "loosely". There 
>> is no fixed entity. Delta's are generated against any random other version 
>> that git deems to be a good delta candidate (with various fairly 
>> successful heursitics), and there are absolutely no hard grouping rules.
>
> I'd like to learn more about that.  Can someone point me to
> either more documentation on it?  In the absence of that,
> perhaps a pointer to the source code that implements it?

See Documentation/technical/pack-heuristics.txt, but the document predates and does not talk about delta reusing, which was covered here:

    http://thread.gmane.org/gmane.comp.version-control.git/16223/focus=16267

> I guess one question I posit is, would it be more accurate
> to think of this as a "delta net" in a weighted graph rather
> than a "delta chain"?

Yes.