From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id D3AEF1F8C8 for ; Wed, 6 Oct 2021 17:48:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234302AbhJFRuu (ORCPT ); Wed, 6 Oct 2021 13:50:50 -0400 Received: from pb-smtp21.pobox.com ([173.228.157.53]:65485 "EHLO pb-smtp21.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234560AbhJFRus (ORCPT ); Wed, 6 Oct 2021 13:50:48 -0400 Received: from pb-smtp21.pobox.com (unknown [127.0.0.1]) by pb-smtp21.pobox.com (Postfix) with ESMTP id 611D415AB72; Wed, 6 Oct 2021 13:48:55 -0400 (EDT) (envelope-from junio@pobox.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=uuBwBwSS3XGN/AWR7cdDmKULIAKXPjGwiTuXsG hNsT4=; b=JZlpBZ7W2CfrIXQGe42f1Cz09vJvDq9NnKEUZIs5v3xq8XJv8IhSmP eq3yycRu/WiDygOvE7I9HBZCQ+p77DO+4Q8W45OBZiVrhplUa5WXYmUq/LnLsCei 57/hHklXJRBdKbyQ20nWq2NM6wVbRnxOGTDWmzTIXRSBrzyT4xP4I= Received: from pb-smtp21.sea.icgroup.com (unknown [127.0.0.1]) by pb-smtp21.pobox.com (Postfix) with ESMTP id 5AA8615AB71; Wed, 6 Oct 2021 13:48:55 -0400 (EDT) (envelope-from junio@pobox.com) Received: from pobox.com (unknown [104.133.2.91]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp21.pobox.com (Postfix) with ESMTPSA id B15D215AB70; Wed, 6 Oct 2021 13:48:52 -0400 (EDT) (envelope-from junio@pobox.com) From: Junio C Hamano To: Elijah Newren Cc: Victoria Dye via GitGitGadget , Git Mailing List , Derrick Stolee , Taylor Blau , Bagas Sanjaya , Victoria Dye Subject: Re: [PATCH v2 4/7] reset: integrate with sparse index References: <49813c8d9ed94fd56f30eb204d346eb5a30473ca.1633440057.git.gitgitgadget@gmail.com> Date: Wed, 06 Oct 2021 10:48:51 -0700 In-Reply-To: (Elijah Newren's message of "Tue, 5 Oct 2021 19:15:55 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Pobox-Relay-ID: AB66BC5E-26CD-11EC-945A-98D80D944F46-77302942!pb-smtp21.pobox.com Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Elijah Newren writes: > On Tue, Oct 5, 2021 at 6:21 AM Victoria Dye via GitGitGadget > wrote: >> >> From: Victoria Dye >> >> `reset --soft` does not modify the index, so no compatibility changes are >> needed for it to function without expanding the index. For all other reset >> modes (`--mixed`, `--hard`, `--keep`, `--merge`), the full index is >> explicitly expanded with `ensure_full_index` to maintain current behavior. > > "to maintain current behavior"? You are changing code here, which > suggests some kind of behavior is changing, but that description seems > to be claiming the opposite. Is it some kind of preventative change > to add ensure_full_index calls in an additional place, with a later > patch in the series intending to remove the other one(s), so you're > making sure that later changes won't cause unwanted behavioral > changes? Or was something else meant here? > > If the above wasn't what you meant, but you're adding > ensure_full_index calls, does that suggest that we had some important > code paths that were not protected by such calls? The original called read_cache() before we know which mode we operate in, near the end of parse_args(), which resulted in an unconditional call to ensure_full_index() in repo_read_index(). This patch delays the call to read_cache(). If parse_pathspec() and everything the original called after the point where it called read_cache() needed to have a populated in-core index, the change can break things---I didn't check thoroughly, but I am guessing it is OK. >> Additionally, the `read_cache()` check verifying an uncorrupted index is >> moved after argument parsing and preparing the repo settings. The index is >> not used by the preceding argument handling, but `read_cache()` does need to >> be run after enabling sparse index for the command and before resetting. > > This seems to be discussing what code changes are being made, but not > why. I'm guessing at the reasoning, but is it something along the > lines of: > > """ > Also, make sure to read_cache() after setting > command_requires_full_index = 0, so that we don't unnecessarily expand > the index as part of our early index-corruption check. > """ I think it is more like "we used to expand very early for all modes, but with this change we move the read_cache() call to much later, and force it not to expand. The modes that call read_from_tree() needs in-core index fully expanded, so we do so there, but the soft reset does not call it and would stop expanding."