From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Subject: Re: [PATCH] pack-objects: use of version 3 delta is now optional. Date: Sun, 15 Oct 2006 14:30:46 -0400 (EDT) Message-ID: References: <7v4pu62ite.fsf@assigned-by-dhcp.cox.net> <7virim10rb.fsf@assigned-by-dhcp.cox.net> <7vac3xzbze.fsf@assigned-by-dhcp.cox.net> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: git@vger.kernel.org, Linus Torvalds X-From: git-owner@vger.kernel.org Sun Oct 15 20:31:31 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 1GZAlj-0006qf-Ox for gcvg-git@gmane.org; Sun, 15 Oct 2006 20:31:28 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161080AbWJOSat (ORCPT ); Sun, 15 Oct 2006 14:30:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161087AbWJOSat (ORCPT ); Sun, 15 Oct 2006 14:30:49 -0400 Received: from relais.videotron.ca ([24.201.245.36]:33006 "EHLO relais.videotron.ca") by vger.kernel.org with ESMTP id S1161080AbWJOSar (ORCPT ); Sun, 15 Oct 2006 14:30:47 -0400 Received: from xanadu.home ([74.56.106.175]) by VL-MO-MR003.ip.videotron.ca (Sun Java System Messaging Server 6.2-2.05 (built Apr 28 2005)) with ESMTP id <0J76007CRWRAAOA0@VL-MO-MR003.ip.videotron.ca> for git@vger.kernel.org; Sun, 15 Oct 2006 14:30:47 -0400 (EDT) In-reply-to: <7vac3xzbze.fsf@assigned-by-dhcp.cox.net> X-X-Sender: nico@xanadu.home To: Junio C Hamano Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: On Sun, 15 Oct 2006, Junio C Hamano wrote: > Nicolas Pitre writes: > > > If anything, maybe this patch can be added before v1.4.3 is released: > >... > > This way pack v3 could be fed to GIT v1.4.3 and above whenever we add > > back pack v3 generation, and a pack converted to v2 from any v3 on the > > fly when that capability is not present. > > I think that is sensible. I also was thinking that we should > call the current one packv3 and the one with delta-base-offset > packv4. I think we should not. The pack version should be tied to incompatible pack data to prevent older GIT versions from misinterpreting newer packs. The delta block copy encoding is a perfect example of that where a bit changed meaning. The delta-base-offset case included a new object type that wasn't used before hence there is no room for confusion, and yet that new delta object could be encoded according to pack version 2 or pack version 3 which makes it orthogonal to the pack version itself. Nicolas