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=-3.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD shortcircuit=no autolearn=ham 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 C9E471F404 for ; Tue, 3 Apr 2018 18:25:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753017AbeDCSZH (ORCPT ); Tue, 3 Apr 2018 14:25:07 -0400 Received: from mail-pl0-f44.google.com ([209.85.160.44]:43839 "EHLO mail-pl0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752892AbeDCSYy (ORCPT ); Tue, 3 Apr 2018 14:24:54 -0400 Received: by mail-pl0-f44.google.com with SMTP id c21-v6so6396595plz.10 for ; Tue, 03 Apr 2018 11:24:54 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=R00r3vJPB62numpHpC7c+9Gl8PYjTkK4Txa7B4cmO3g=; b=GXYN1B156mNdxD8GNQYwTBniE6P3V03tbLj2dXYElJnJ73yQ1FZTNtfp37ZqQg5L5J NI2MgMmwfVOPoXxzGqlx1d2/kl26NNi4A9El7Id9q40S6SmetyRgC18CRnC4eZt6p2ly JTx5ECWbA2xY/GtGy6s414eEsSwzep10Oyne8VwYj7DOoiVTSYhVgIiCmrDEsBbFGHk5 sAMaN/dmOalx3IbpC6427amTKigmN1Y5s58JobzgYLapVV24ZWSV4NlNL8G3GFyXe7hr 146zfGqLqpV7GSsA0RYep5PqoPe8Kf0mVMYBBG/bt4FIcHflpj+pMPXJQO8Iv37vYUc5 +Gbg== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=R00r3vJPB62numpHpC7c+9Gl8PYjTkK4Txa7B4cmO3g=; b=D0YTHEdrLAGEVn+G5lhY2438Azu9z+dCtJ17+W26E155eILwRucEsQBWbH6zT9HZ/I 9SvvWDz+jOPjpdFKZ1L/rpmYeUXxYl6f5tcxhXRikLv7QNS7tbVaAE8GZ0rUGl0Fv/ck A5dLsSlV0rlv4Wy9HTBxjAwPLY8zrNDPFBGgkUByFuo+GqFqeYCVCIGJQzyv3MVl4uXE Rjan1Ti7zAW8SeqExMuocSb0zq3SbtW9BA+Ye/9Ofgnar+d3IEJZDttNjkB20dlA6ONX llYDAQn3C1AvFCm43eEIYzfF0xljW31Csb6zcHlzX8JF5M7lq+TIJarZl1Yc5Ig8K6MB wPaQ== X-Gm-Message-State: AElRT7HoHgerImlzOHnp++pxo7B6pQioTSW1SfP5Ts+sg9K3TsJgLfII XbTImAcEaGoBol2YyGW3y1cyJQ== X-Google-Smtp-Source: AIpwx4+n8/m8XEsTvuHgL6gEcRjNFuMizDWJPIWFqzrBqrvNgWNUKcyzHTa9eaysKvYK5sUwQgpyMQ== X-Received: by 10.98.198.7 with SMTP id m7mr7916337pfg.66.1522779894061; Tue, 03 Apr 2018 11:24:54 -0700 (PDT) Received: from twelve3.svl.corp.google.com ([2620:0:100e:422:ffac:c1d4:4bf7:bb93]) by smtp.gmail.com with ESMTPSA id y20sm6087795pfe.20.2018.04.03.11.24.52 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 03 Apr 2018 11:24:53 -0700 (PDT) Date: Tue, 3 Apr 2018 11:24:52 -0700 From: Jonathan Tan To: Derrick Stolee Cc: git@vger.kernel.org, avarab@gmail.com, sbeller@google.com, larsxschneider@gmail.com, peff@peff.net Subject: Re: [PATCH 2/6] commit: add generation number to struct commmit Message-Id: <20180403112452.96ebcfcdfd68181d1d269171@google.com> In-Reply-To: <20180403165143.80661-3-dstolee@microsoft.com> References: <20180403165143.80661-1-dstolee@microsoft.com> <20180403165143.80661-3-dstolee@microsoft.com> X-Mailer: Sylpheed 3.6.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Tue, 3 Apr 2018 12:51:39 -0400 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 > information to revision walks. We use two special values to signal > the generation number is invalid: > > GENERATION_NUMBER_UNDEF 0xFFFFFFFF > GENERATION_NUMBER_NONE 0 > > The first (_UNDEF) means the generation number has not been loaded or > computed. The second (_NONE) means the generation number was loaded > from a commit graph file that was stored before generation numbers > were computed. > > Signed-off-by: Derrick Stolee This looks straightforward and correct, thanks. I think some of the description above should appear as code comments. > +#define GENERATION_NUMBER_UNDEF 0xFFFFFFFF > +#define GENERATION_NUMBER_NONE 0 I would include the description above here as documentation, and would replace "was stored before generation numbers were computed" by "was written by a version of Git that did not support generation numbers".