From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCHv3] Documentation: describe --thin more accurately Date: Thu, 18 Feb 2010 00:33:16 -0800 Message-ID: <4B7CFB4C.2020507@gmail.com> References: <1265961646-28585-1-git-send-email-bebarino@gmail.com> <1266262395-11864-1-git-send-email-bebarino@gmail.com> <7vfx52xm8d.fsf@alter.siamese.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: git@vger.kernel.org, Nicolas Pitre To: Junio C Hamano X-From: git-owner@vger.kernel.org Thu Feb 18 09:40:10 2010 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Ni1vd-0004jF-Mg for gcvg-git-2@lo.gmane.org; Thu, 18 Feb 2010 09:40:10 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752889Ab0BRIjt (ORCPT ); Thu, 18 Feb 2010 03:39:49 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:60505 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751623Ab0BRIjs (ORCPT ); Thu, 18 Feb 2010 03:39:48 -0500 Received: by pwj8 with SMTP id 8so1419695pwj.19 for ; Thu, 18 Feb 2010 00:39:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=h0nJU0Bghn6Kjc6p1Sunz8G6kzsleCe6AxhqI8Ufp54=; b=UR6bkowzuy1CTkoNww1VHbcKWagXWyUgrpHt+kCu2BtZSRIBXNbvdcoe3GM1g139gm t50RoYr5oiw9tVr0vna2RbnlIgGX654Id/sxckolNmpvSe5zRj3aZgRG6m1ZDSpsQ1+E qvX/9X9Trv6FqBkznV20hFQrd6O0mwZ5PMKos= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=Yw6n/ms0mlBcy4o0SfR4JkFLvJ7n0zBPI11RZwSdMydhelx7LPvG/JjVu+klxWIzLU d9hCWSN863XOvcNBDk8+nE0a9SE2CedXitvpKgKzsbOE8VPC8Lmxt+0wluxDPi0xPYqt bCI5d7lVT7KXuiUiQvEZSaYz/vxRvcK44iTBc= Received: by 10.114.187.40 with SMTP id k40mr3674078waf.10.1266481999291; Thu, 18 Feb 2010 00:33:19 -0800 (PST) Received: from ?192.168.1.5? (user-0c9haca.cable.mindspring.com [24.152.169.138]) by mx.google.com with ESMTPS id 22sm9538984pzk.13.2010.02.18.00.33.17 (version=SSLv3 cipher=RC4-MD5); Thu, 18 Feb 2010 00:33:18 -0800 (PST) User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.7pre) Gecko/20091214 Shredder/3.0.1pre In-Reply-To: <7vfx52xm8d.fsf@alter.siamese.dyndns.org> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On 02/15/2010 12:44 PM, Junio C Hamano wrote: > I however think the first two points might be better covered by the > description of `--thin` of `pack-objects` and we should simply refer to it > from here, like this: > > --fix-thin:: > Make a "thin" pack produced by `git pack-objects --thin` (see > linkgit:git-pack-objects[1] for details) directly usable by > git, by adding objects that the objects stored in the > deltified form are based on to the packfile. > This looks good. I'd like to avoid introducing the term packfile though and just use pack throughout. > --thin:: > Create a "thin" pack in order to reduce network transfer. > + > For a packfile to be usable directly by git, any object in the pack > that is represented in the deltified form must be based on an object > that exists in the same pack. Such a pack is called "self-contained". > + > If the sender sends an object in the deltified form based on an object > both the sender and the receiver have, but excludes the common object > itself from the datastream, it can often reduce the network traffic > dramatically. Such a datastream is called a "thin" pack. > + > Note that a thin pack violates the self-containedness requirement and > is not directly usable by git on the receiving end without making it a > self-contained pack by running `git index-pack --fix-thin` (see > linkgit:git-index-pack[1]). This looks long winded. Perhaps we can do without explaining what self-containedness is? If you read the second paragraph in the description section of git-pack-objects.txt it tries to explain self-contained: The packed archive format (.pack) is designed to be self-contained so that it can be unpacked without any further information If all I know is a pack contains objects and deltas based on other objects I might be able to figure out that all the objects must be present in the pack for it to be self-contained. This description section might need some work but I don't think repeating ourselves in --thin is good. Updated patch to follow.