From patchwork Sat Jun 11 02:44:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Han Xin X-Patchwork-Id: 12878322 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11F6BC43334 for ; Sat, 11 Jun 2022 02:45:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238953AbiFKCpL (ORCPT ); Fri, 10 Jun 2022 22:45:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349718AbiFKCpD (ORCPT ); Fri, 10 Jun 2022 22:45:03 -0400 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 735273F62C5 for ; Fri, 10 Jun 2022 19:44:58 -0700 (PDT) Received: by mail-pl1-x62d.google.com with SMTP id t2so732443pld.4 for ; Fri, 10 Jun 2022 19:44:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=JwBjxKyIkVBuOPUHp1A97ClrKGi3RzEhKlM7mpYh2eg=; b=Orbllgx3IZyk0GVf6gBnb74s8FwM9ysnmJwPdqTiXgyZG3bII6NLlcCX18CzJz+K8a Kj94aLdU7BYEjHEvTNTurf+6vsBjx7tETUX6NNMXXHJUYwrdJ8iHFdqZwpRs/OMZ9dUK LTQcmRRQLG1IkDYnLbVdGZ1rc5lnx3AZO6W9UBBxFp0Lu0dH5rsOTcJdKZx+2wV9v9ZU lpJSKuSZs17a/xzPwaRxHOPLzlyQsNzUTBYItFbp1t0yWF4vjg9kOMqLI0z/oikurmGI NR+wEDcl4dE8qNMLSJX6BVLuN2DTY7qUBsYnJZaGcQr0eqae+Q6pITCixVRNsaWiEu3U MlCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=JwBjxKyIkVBuOPUHp1A97ClrKGi3RzEhKlM7mpYh2eg=; b=47YKfYswdYlw4hBIU5hVrkpwMCQu34l+ZXaEtYtsK2YbCOTlWT0xCPVLLTM7Fsh2fN NZoDsnWcR0Qo2conCpoTSPU8x2IZol92xGYPggcM9gYulgl5T6dk+NScf/ykAzPY4tat 3MDJxwgCa9FRN4/oOkjENP6/uHQlTFSrPY19GMI1sWF4tLpd4qs957fm21JaZWOdZBg9 14eQQ8352BS63Vp90NaONkFeXaD35/MbXzAxiGBo+pK2JVsSYtqse6PUO0JUPmWe5Cpp RaXA3bcnwnAudEl3KuUAUDWVlY23JCUSZfIDwc9f6PNvQf+2qmF0I9O3t1dDhMD1/kDf kJMQ== X-Gm-Message-State: AOAM531M/MSzLEnw1o0kG9YQLKqQT6Cfw4YJall8hShT4SWLUSVcTNNv 3OzQS2rR2PWTFW5/dUZLXa4= X-Google-Smtp-Source: ABdhPJxiB/T5wPosxuu0khjTlwWMakYzXM3ZrSqKmu5x9CxLLjRDfOFra/PtUV3djc/g15fAbIkYtg== X-Received: by 2002:a17:902:ca0b:b0:167:4c4d:7320 with SMTP id w11-20020a170902ca0b00b001674c4d7320mr40255507pld.113.1654915497617; Fri, 10 Jun 2022 19:44:57 -0700 (PDT) Received: from localhost.localdomain ([2409:8a28:80c:ca60:6957:cd88:1852:9438]) by smtp.gmail.com with ESMTPSA id l13-20020a62be0d000000b0051ba90d55acsm257077pff.207.2022.06.10.19.44.53 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Fri, 10 Jun 2022 19:44:57 -0700 (PDT) From: Han Xin To: avarab@gmail.com Cc: chiyutianyi@gmail.com, git@vger.kernel.org, gitster@pobox.com, l.s.r@web.de, neerajsi@microsoft.com, newren@gmail.com, philipoakley@iee.email, stolee@gmail.com, worldhello.net@gmail.com, Neeraj Singh Subject: [PATCH v15 5/6] core doc: modernize core.bigFileThreshold documentation Date: Sat, 11 Jun 2022 10:44:20 +0800 Message-Id: <61ae1c1632582ba1cfd9e15e375c57fdb3f559af.1654914555.git.chiyutianyi@gmail.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Ævar Arnfjörð Bjarmason The core.bigFileThreshold documentation has been largely unchanged since 5eef828bc03 (fast-import: Stream very large blobs directly to pack, 2010-02-01). But since then this setting has been expanded to affect a lot more than that description indicated. Most notably in how "git diff" treats them, see 6bf3b813486 (diff --stat: mark any file larger than core.bigfilethreshold binary, 2014-08-16). In addition to that, numerous commands and APIs make use of a streaming mode for files above this threshold. So let's attempt to summarize 12 years of changes in behavior, which can be seen with: git log --oneline -Gbig_file_thre 5eef828bc03.. -- '*.c' To do that turn this into a bullet-point list. The summary Han Xin produced in [1] helped a lot, but is a bit too detailed for documentation aimed at users. Let's instead summarize how user-observable behavior differs, and generally describe how we tend to stream these files in various commands. 1. https://lore.kernel.org/git/20220120112114.47618-5-chiyutianyi@gmail.com/ Helped-by: Han Xin Signed-off-by: Ævar Arnfjörð Bjarmason --- Documentation/config/core.txt | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt index 41e330f306..87e4c04836 100644 --- a/Documentation/config/core.txt +++ b/Documentation/config/core.txt @@ -444,17 +444,32 @@ You probably do not need to adjust this value. Common unit suffixes of 'k', 'm', or 'g' are supported. core.bigFileThreshold:: - Files larger than this size are stored deflated, without - attempting delta compression. Storing large files without - delta compression avoids excessive memory usage, at the - slight expense of increased disk usage. Additionally files - larger than this size are always treated as binary. + The size of files considered "big", which as discussed below + changes the behavior of numerous git commands, as well as how + such files are stored within the repository. The default is + 512 MiB. Common unit suffixes of 'k', 'm', or 'g' are + supported. + -Default is 512 MiB on all platforms. This should be reasonable -for most projects as source code and other text files can still -be delta compressed, but larger binary media files won't be. +Files above the configured limit will be: + -Common unit suffixes of 'k', 'm', or 'g' are supported. +* Stored deflated in packfiles, without attempting delta compression. ++ +The default limit is primarily set with this use-case in mind. With it, +most projects will have their source code and other text files delta +compressed, but not larger binary media files. ++ +Storing large files without delta compression avoids excessive memory +usage, at the slight expense of increased disk usage. ++ +* Will be treated as if they were labeled "binary" (see + linkgit:gitattributes[5]). e.g. linkgit:git-log[1] and + linkgit:git-diff[1] will not compute diffs for files above this limit. ++ +* Will generally be streamed when written, which avoids excessive +memory usage, at the cost of some fixed overhead. Commands that make +use of this include linkgit:git-archive[1], +linkgit:git-fast-import[1], linkgit:git-index-pack[1] and +linkgit:git-fsck[1]. core.excludesFile:: Specifies the pathname to the file that contains patterns to