From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: Millisecond precision in timestamps? Date: Tue, 27 Nov 2012 22:30:09 -0500 Message-ID: <20121128033009.GA3931@sigill.intra.peff.net> References: <20121127204828.577264065F@snark.thyrsus.com> <7vzk22lmz9.fsf@alter.siamese.dyndns.org> <20121127230419.GA26080@thyrsus.com> <20121128001231.GA27971@thyrsus.com> <20121128011750.GA23498@sigill.intra.peff.net> <20121128032337.GB1669@thyrsus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Shawn Pearce , Felipe Contreras , Junio C Hamano , git To: "Eric S. Raymond" X-From: git-owner@vger.kernel.org Wed Nov 28 04:30:36 2012 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1TdYM2-0002lN-Nj for gcvg-git-2@plane.gmane.org; Wed, 28 Nov 2012 04:30:31 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751989Ab2K1DaN (ORCPT ); Tue, 27 Nov 2012 22:30:13 -0500 Received: from 75-15-5-89.uvs.iplsin.sbcglobal.net ([75.15.5.89]:58955 "EHLO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751697Ab2K1DaM (ORCPT ); Tue, 27 Nov 2012 22:30:12 -0500 Received: (qmail 2201 invoked by uid 107); 28 Nov 2012 03:31:07 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) (smtp-auth username relayok, mechanism cram-md5) by peff.net (qpsmtpd/0.84) with ESMTPA; Tue, 27 Nov 2012 22:31:07 -0500 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Tue, 27 Nov 2012 22:30:09 -0500 Content-Disposition: inline In-Reply-To: <20121128032337.GB1669@thyrsus.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Tue, Nov 27, 2012 at 10:23:37PM -0500, Eric S. Raymond wrote: > Jeff King : > > But I really wonder if anybody actually cares about adding sub-second > > timestamp support, or if it is merely "because SVN has it". > > There's actually one possible other reason to care. 1-second granularity > isn't quite fine enough to guarantee that a (committer, timestamp) > pair is a unique key. 1 microsecond granularity would be. You can't guarantee that such a pair is unique, anyway, due to clock skew. A much more compelling argument to me would be that you are doing some bidirectional magic between git and svn, and you want to make make sure that an svn->git->svn translation will result in the exact same bytes. Then the argument is still "because SVN has it", but at least it is "and we interoperate with it" and not simply chasing a cool but useless feature. -Peff