From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Narebski Subject: Re: VCS comparison table Date: Wed, 18 Oct 2006 01:35:24 +0200 Message-ID: <200610180135.24606.jnareb@gmail.com> References: <9e4733910610140807p633f5660q49dd2d2111c9f5fe@mail.gmail.com> <453536AE.6060601@utoronto.ca> <200610172301.27101.jnareb@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Andreas Ericsson , bazaar-ng@lists.canonical.com, git@vger.kernel.org X-From: git-owner@vger.kernel.org Wed Oct 18 02:05:39 2006 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by ciao.gmane.org with esmtp (Exim 4.43) id 1GZyw5-0001A5-Pt for gcvg-git@gmane.org; Wed, 18 Oct 2006 02:05:30 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751130AbWJQXey convert rfc822-to-quoted-printable (ORCPT ); Tue, 17 Oct 2006 19:34:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751143AbWJQXey (ORCPT ); Tue, 17 Oct 2006 19:34:54 -0400 Received: from ug-out-1314.google.com ([66.249.92.174]:37547 "EHLO ug-out-1314.google.com") by vger.kernel.org with ESMTP id S1751130AbWJQXex (ORCPT ); Tue, 17 Oct 2006 19:34:53 -0400 Received: by ug-out-1314.google.com with SMTP id o38so70252ugd for ; Tue, 17 Oct 2006 16:34:52 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:from:to:subject:date:user-agent:cc:references:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:message-id; b=cb6zwygvrfWpYqLEmBF8G/UP0b2aXY5tn60mECn09pR7dj6fo+14v8TdX3XbUc/8DBvF3cGTFUsJL7rMQJXQgwXCYENjVlWBTAz+LX7PLGUvSM2N7TNWy5MxsABCvz3gpM94qdnz/vSjwQI/6W8aIsX6izO1+YituoGoTj1tZ3s= Received: by 10.66.249.11 with SMTP id w11mr10756324ugh; Tue, 17 Oct 2006 16:34:52 -0700 (PDT) Received: from host-81-190-17-207.torun.mm.pl ( [81.190.17.207]) by mx.google.com with ESMTP id z40sm249183ugc.2006.10.17.16.34.51; Tue, 17 Oct 2006 16:34:51 -0700 (PDT) To: Aaron Bentley User-Agent: KMail/1.9.3 In-Reply-To: <200610172301.27101.jnareb@gmail.com> Content-Disposition: inline Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: Dnia wtorek 17. pa=BCdziernika 2006 23:01, Jakub Narebski napisa=B3: > Aaron Bentley wrote: > > Andreas Ericsson wrote: > >> Aaron Bentley wrote: > >>> Ah. =A0Bazaar uses negative numbers to refer to th parents, an= d > >>> positive numbers to refer to the number of commits that have been= made > >>> since the branch was initialized. > >>> > >> > >> What do you do once a branch has been thrown away, or has had 20 o= ther > >> branches merged into it? Does the offset-number change for the rev= ision > >> then, or do you track branch-points explicitly? > >=20 > > We always track the number of parents since the initial commit in t= he > > project. =A0Sorry, I don't think I said that clearly before. >=20 > While this I think is quite reliable (there was idea to store "genera= tion > number" with each commit, e.g. using not implemented "note" header, o= r > commit-id to generation number "database" as a better heuristic than > timestamp for revision ordering in git-rev-list output), and probably > independent on repository (it is global property of commit history, > and commit history is included in sha1 of its parents), numbering bra= nching > points is unreliable, as is relying on branch names. Take for example the following situation: In the following we had A--B--C--D - repository A we have cloned repository A--B--C--D - repository B Then, in parallel/independently we branched off C in repository A, and branched off B in repository B -x / A--B--C--D - repository A A--B--C--D - repository B \ -y If we then fetch changes from B into A, and fetch changes from A into B= , we will have that in repository A branch off C appeared earlier, and in repository B branch off C appeared later. --=20 Jakub Narebski Poland