From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-1.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD shortcircuit=no autolearn=no autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 10C651F404 for ; Tue, 3 Apr 2018 18:32:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752829AbeDCScE (ORCPT ); Tue, 3 Apr 2018 14:32:04 -0400 Received: from mail-pl0-f68.google.com ([209.85.160.68]:35005 "EHLO mail-pl0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752525AbeDCScD (ORCPT ); Tue, 3 Apr 2018 14:32:03 -0400 Received: by mail-pl0-f68.google.com with SMTP id 61-v6so8062776plb.2 for ; Tue, 03 Apr 2018 11:32:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=hjDnU7TnjBUyNwYKmandXTkJ2r22a2GuoOJ09tw3K0k=; b=CjVrdsT86+TUH7WJW3ABFjHgvHHr8VH+WPmtsNQ+WnYoqIHiieqjo1Lki/heAq4UcE 0CQQge2gN0d+L74JgMwODXzQCqgo8r5osd+qOaq73wtZTPlOvl2uNsUXvrgvzkAINA7F 6w9qYd+NA8/RhBJ+oFo9p/yh3NJdyzn6JL01IldwMV8KTqYLwB4Lph7j1WRVvziaoI59 K2Kwo/NEjbxTQ8o70XOndqRg28eTx1s7WcebSea1k5tVto85fRbPAYY33aGbm59hslUm 2O4CXVI/SujEbcZN4pvPRHIIUF3/46WZEe0jI/wlGmqFVx9s0JrTze6watYO3EZJUgP/ BEuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=hjDnU7TnjBUyNwYKmandXTkJ2r22a2GuoOJ09tw3K0k=; b=BP+kk2cQxaIa0YaAohj/Q9Lp0VEybdy7KD84rjYy5kSBUQ99Bvi3IQNu9fT5gOMWuq lkZCXa4AxVbZlozG8epcciDgLfv+UbKmk974pi1hFe0TfzXKA+DECLa/vBBh0OJPcz9s FKPIqVxO7UK2kwiQKQvajckIgPHSodSu5qz44II87Tcp3xmmeCpoqX62/Yo3WLhCAsJx YcEBhSkq8Cgffz1LqFkDs3z4NJS4AR5pbpBLCqi2uTWFKKuBdTDBSKPNG2NIY+myS5Hq ro4x9CRR6b3A5GYXAvK0daa72J6xapLqigYsbt47G+Uby+O5ArFO4Y4kUS0Yivizin3K a3+g== X-Gm-Message-State: AElRT7GlLUmsyLxgn9mv6vKYIboqan2gM5uUO80kNWWR5lGOAHQZ/TFY YRzvPF6YCRXQ6Ug42IHMiF0c7ngfIzw= X-Google-Smtp-Source: AIpwx4/65lMwuPxymcEktTAs4TPq57iBQjok9ces6/AFL6CZmSyBxSZKjYuSx6ZVkQCFAV9X3FOV+A== X-Received: by 10.99.49.84 with SMTP id x81mr5206122pgx.38.1522780322865; Tue, 03 Apr 2018 11:32:02 -0700 (PDT) Received: from google.com ([2620:0:100e:422:ff43:9291:7eda:b712]) by smtp.gmail.com with ESMTPSA id c15sm7034779pfm.114.2018.04.03.11.32.01 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 03 Apr 2018 11:32:02 -0700 (PDT) Date: Tue, 3 Apr 2018 11:32:01 -0700 From: Brandon Williams To: Jeff King Cc: Derrick Stolee , git@vger.kernel.org, avarab@gmail.com, sbeller@google.com, larsxschneider@gmail.com Subject: Re: [PATCH 2/6] commit: add generation number to struct commmit Message-ID: <20180403183201.GC100220@google.com> References: <20180403165143.80661-1-dstolee@microsoft.com> <20180403165143.80661-3-dstolee@microsoft.com> <20180403180536.GB100220@google.com> <20180403182800.GA8377@sigill.intra.peff.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180403182800.GA8377@sigill.intra.peff.net> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On 04/03, Jeff King wrote: > On Tue, Apr 03, 2018 at 11:05:36AM -0700, Brandon Williams wrote: > > > On 04/03, Derrick Stolee wrote: > > > The generation number of a commit is defined recursively as follows: > > > > > > * If a commit A has no parents, then the generation number of A is one. > > > * If a commit A has parents, then the generation number of A is one > > > more than the maximum generation number among the parents of A. > > > > > > Add a uint32_t generation field to struct commit so we can pass this > > > > Is there any reason to believe this would be too small of a value in the > > future? Or is a 32 bit unsigned good enough? > > The linux kernel took ~10 years to produce 500k commits. Even assuming > those were all linear (and they're not), that gives us ~80,000 years of > leeway. So even if the pace of development speeds up or we have a > quicker project, it still seems we have a pretty reasonable safety > margin. > > -Peff I figured as much, but just wanted to check since the windows folks seems to produce commits pretty quickly. -- Brandon Williams