From patchwork Tue Jun 13 17:39:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Tan X-Patchwork-Id: 13279109 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 DA54AEB64D8 for ; Tue, 13 Jun 2023 17:40:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234961AbjFMRkY (ORCPT ); Tue, 13 Jun 2023 13:40:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240069AbjFMRkL (ORCPT ); Tue, 13 Jun 2023 13:40:11 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D922692 for ; Tue, 13 Jun 2023 10:40:10 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-bd69ee0edacso382167276.3 for ; Tue, 13 Jun 2023 10:40:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1686678010; x=1689270010; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=M7KQnfd1RrJljfgV3vlc4SkWbQ9MGK7nBO1blgrMwQU=; b=vtNoLPljHlPLaAGR0omf7PBhig7+ZwiOxgGFRpuQamNqHhyhAGc/cOq24sC71dKBNm arl1E5XbXKAZBSrPE86xn+Rc5dK/f4KrLhSfZ3c20aA5TPzX6uMEb+pn3oC8YtQEXhgs TsTL0bqeIikBT1K9PPEIVX/SkBAbV809kXPTyz1UvoEKR4SS1QdNlFkrRA4/VRmn8nDJ cGY4RzdMgs6QQD+MqIroLktwd8O5UChQp3l/ZdIjK3v0hYAp1pkMLj7NAuerVBdVWwnM Vcf8G7TJ57osavqTqWAg4WQrQSZbPpAwmxksjeAOVBw+a4k7x4pzFotZadJzejV1SroL EURg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686678010; x=1689270010; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=M7KQnfd1RrJljfgV3vlc4SkWbQ9MGK7nBO1blgrMwQU=; b=DMWIRDDxlIanZ9VTPOTAbbOCUIGJFqqCPc2kkYphXzwqTK0l6pwMjqFSyMUMtnVUwW 8dpMwN8CchLTwPNtMPvtYpUBtEx5a0nY2xb3FpnPKprw6v3+kT3jNEd2dXDSv2rsNFcR fLyblPbNKtYT+Jqb9aZOH2aPG33StTKMU/vScooUdxKBZbz4hFVMpG5tPXno+V+1IsBL K2oAwKPG5WjsBLmmMnOx9YLNx/uXvU9Z8De5JQGb1XQXrXNlsB4JJKJ+yWtWg89BwYm9 Tpx/eYAMPfdiEdtUpv6Esm3VB16JxcBIkZsMVayryjJ/sqU+S15ZdXMc0jcIyGPkX7g9 7nmg== X-Gm-Message-State: AC+VfDwQRE1gwd1+SVzDm1FxyJ1siWJX/w68hiwdDfwtBhyAloksh7Jh 5vCZTTwRXoscXp1+myU0+6YzTmkNkr49yCRqXC57LXFD0NtblAAFSozRjDC5rGQMvoD4UiwPlhv v7rRowcgXejhalq08MRG4wAsBo3jgG3G8BVdkaVU8HZpLtwbnLv34A0vRm9xyMJrPsjPc0GZP26 Au X-Google-Smtp-Source: ACHHUZ6YPN0GSBqL4iX7i2OHdLctm28TVfndK0Vx9+7eFtstlbil2JAGSnwpvZV4juHpipnpbsW3xB0XdqWqWMPxZuq/ X-Received: from jonathantanmy0.svl.corp.google.com ([2620:15c:2d3:202:5e39:4d58:c992:1db0]) (user=jonathantanmy job=sendgmr) by 2002:a25:4487:0:b0:bad:4bb:c440 with SMTP id r129-20020a254487000000b00bad04bbc440mr1051892yba.10.1686678010094; Tue, 13 Jun 2023 10:40:10 -0700 (PDT) Date: Tue, 13 Jun 2023 10:39:55 -0700 In-Reply-To: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-goog Message-ID: Subject: [PATCH v4 1/4] gitformat-commit-graph: describe version 2 of BDAT From: Jonathan Tan To: git@vger.kernel.org Cc: Jonathan Tan , Ramsay Jones , Junio C Hamano Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org The code change to Git to support version 2 will be done in subsequent commits. Signed-off-by: Jonathan Tan --- Documentation/gitformat-commit-graph.txt | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/Documentation/gitformat-commit-graph.txt b/Documentation/gitformat-commit-graph.txt index 31cad585e2..112e6d36a6 100644 --- a/Documentation/gitformat-commit-graph.txt +++ b/Documentation/gitformat-commit-graph.txt @@ -142,13 +142,16 @@ All multi-byte numbers are in network byte order. ==== Bloom Filter Data (ID: {'B', 'D', 'A', 'T'}) [Optional] * It starts with header consisting of three unsigned 32-bit integers: - - Version of the hash algorithm being used. We currently only support - value 1 which corresponds to the 32-bit version of the murmur3 hash + - Version of the hash algorithm being used. We currently support + value 2 which corresponds to the 32-bit version of the murmur3 hash implemented exactly as described in https://en.wikipedia.org/wiki/MurmurHash#Algorithm and the double hashing technique using seed values 0x293ae76f and 0x7e646e2 as described in https://doi.org/10.1007/978-3-540-30494-4_26 "Bloom Filters - in Probabilistic Verification" + in Probabilistic Verification". Version 1 bloom filters have a bug that appears + when char is signed and the repository has path names that have characters >= + 0x80; Git supports reading and writing them, but this ability will be removed + in a future version of Git. - The number of times a path is hashed and hence the number of bit positions that cumulatively determine whether a file is present in the commit. - The minimum number of bits 'b' per entry in the Bloom filter. If the filter From patchwork Tue Jun 13 17:39:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Tan X-Patchwork-Id: 13279108 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 C84E6EB64D7 for ; Tue, 13 Jun 2023 17:40:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231836AbjFMRkW (ORCPT ); Tue, 13 Jun 2023 13:40:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240139AbjFMRkO (ORCPT ); Tue, 13 Jun 2023 13:40:14 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BC9C92 for ; Tue, 13 Jun 2023 10:40:13 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-56cea71b98fso53977917b3.0 for ; Tue, 13 Jun 2023 10:40:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1686678012; x=1689270012; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=S5Ld424b2SW5L73WULsBu6R0b4Rdh3QrXIgHBgMO1f4=; b=aukZc02cWg3fpSfzoLUExTQWqmI8ng1qYR/Et5JoiyONpan99pTqHMHyD32D4jzAjg BHo5IkcZlegjMJVLRFLxbWISO0it1UWU/p4ulT0+601A3dIaPugU6e9KL1/WFTaqU4JQ c2YCAkkqgF+YH69OS6TfRrERQeHTajTzDk/PMST+LGL8pHn+NuCqgvQaHeZKfJIhPH18 TZr2fMlOZ2/5ttvQOtme/O58YK19ZkUNPhCALh9T2GVW0lEFO2eeWkGcqnMLcHnbZEzp lsDhemUQ0YqOYdtweahe7ePWaekFcNHzB++Ierx4zHtJQpHoue2aTlzfN86AYloIF5Y5 gqCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686678012; x=1689270012; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=S5Ld424b2SW5L73WULsBu6R0b4Rdh3QrXIgHBgMO1f4=; b=HF7kFvbkzPzAjD4O61sD2+aiAuvDKUlwp3V/rEwwp7LkbCu1NQYulI2inN07rGnGvb /UNTqnoTG35KWC2qckJRzvREVf/rChsQhMtQQPW5n2cfOTAv1fa5s137kNBO0HYEStc4 jzkBfOu9+QyI7WXT5G0Oo2kkD7E8bmd/lGziCepOyqQqEZFUITuF9X+jN2v42lPpJSd8 V53WLE4SfO/beWSno9Ffz9Z5XEwInZo0pjtNwkm5rmvka31Sw3ggV6YOKz1qhBPW5jLO 3NN+pnNNxOfCQsI06zn93TlAHSxZqO51NUmvpw1RZPqYkoOSeTmlaxwKkwYW9DOVlzcz w1+g== X-Gm-Message-State: AC+VfDypR/UWkGHswD+pdNDLZMAk4DgqXRIwNFXHlzbv2+qtmvn+/Hfo m3rKZoL66j5dQ+NKLdeUFsOS4m5wCODHoc9g0glQFJcZoHbj3yQW/8kLefOwcnDJmPU5/BQ2jHP ojD/v34iK6j+TkAk7LAneQ0PCfELN95LI17dvSVDq7QNDAWVTquxjWrz3fOMnW75CZZcPjI7nL0 ZB X-Google-Smtp-Source: ACHHUZ6I9b8/f9ro2AuHoFrWVMuRYe7t9/TMNngVPvlaDI46dn7XpfnX2uRjZAL4wylOYtJD9eLO4idPxwWYKJGMDJ3x X-Received: from jonathantanmy0.svl.corp.google.com ([2620:15c:2d3:202:5e39:4d58:c992:1db0]) (user=jonathantanmy job=sendgmr) by 2002:a05:6902:1447:b0:ba7:8099:c5f2 with SMTP id a7-20020a056902144700b00ba78099c5f2mr479643ybv.8.1686678012250; Tue, 13 Jun 2023 10:40:12 -0700 (PDT) Date: Tue, 13 Jun 2023 10:39:56 -0700 In-Reply-To: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-goog Message-ID: Subject: [PATCH v4 2/4] t4216: test changed path filters with high bit paths From: Jonathan Tan To: git@vger.kernel.org Cc: Jonathan Tan , Ramsay Jones , Junio C Hamano Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Subsequent commits will teach Git another version of changed path filter that has different behavior with paths that contain at least one character with its high bit set, so test the existing behavior as a baseline. Signed-off-by: Jonathan Tan Signed-off-by: Junio C Hamano --- t/t4216-log-bloom.sh | 46 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/t/t4216-log-bloom.sh b/t/t4216-log-bloom.sh index fa9d32facf..baa0c48897 100755 --- a/t/t4216-log-bloom.sh +++ b/t/t4216-log-bloom.sh @@ -404,4 +404,50 @@ test_expect_success 'Bloom generation backfills empty commits' ' ) ' +get_bdat_offset () { + perl -0777 -ne \ + 'print unpack("N", "$1") if /BDAT\0\0\0\0(....)/ or exit 1' \ + .git/objects/info/commit-graph +} + +get_first_changed_path_filter () { + BDAT_OFFSET=$(get_bdat_offset) && + perl -0777 -ne \ + 'print unpack("H*", substr($_, '$BDAT_OFFSET' + 12, 2))' \ + .git/objects/info/commit-graph +} + +# chosen to be the same under all Unicode normalization forms +CENT=$(printf "\302\242") + +test_expect_success 'set up repo with high bit path, version 1 changed-path' ' + git init highbit1 && + test_commit -C highbit1 c1 "$CENT" && + git -C highbit1 commit-graph write --reachable --changed-paths +' + +test_expect_success 'setup check value of version 1 changed-path' ' + (cd highbit1 && + printf "52a9" >expect && + get_first_changed_path_filter >actual) +' + +# expect will not match actual if char is unsigned by default. Write the test +# in this way, so that a user running this test script can still see if the two +# files match. (It will appear as an ordinary success if they match, and a skip +# if not.) +if test_cmp highbit1/expect highbit1/actual +then + test_set_prereq SIGNED_CHAR_BY_DEFAULT +fi +test_expect_success SIGNED_CHAR_BY_DEFAULT 'check value of version 1 changed-path' ' + # Only the prereq matters for this test. + true +' + +test_expect_success 'version 1 changed-path used when version 1 requested' ' + (cd highbit1 && + test_bloom_filters_used "-- $CENT") +' + test_done From patchwork Tue Jun 13 17:39:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Tan X-Patchwork-Id: 13279110 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 27855EB64D7 for ; Tue, 13 Jun 2023 17:40:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239676AbjFMRk0 (ORCPT ); Tue, 13 Jun 2023 13:40:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36490 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240185AbjFMRkR (ORCPT ); Tue, 13 Jun 2023 13:40:17 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B49AC9 for ; Tue, 13 Jun 2023 10:40:15 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5692be06cb2so83503507b3.1 for ; Tue, 13 Jun 2023 10:40:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1686678014; x=1689270014; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=4kUJW+8FaqLzgttrJyg1cSLzKp0rVov2HBJYZBKRSbA=; b=6q8h/LgLKh5UWZurdRJbprexDECsPsmBkXeMO8FRnbVUcfrz9m1G7Az1H5DoXqfN40 0OCIuI1c9LXXhiecbSxbhA9z0yq6Jpe4UblAm5Zw2DJfDdump7UAupwYQrQ19O6mDca6 KqRnXcqcopoHRwPsw7OLUIExC2rmGMND7e6mPdap5xGf/xpeHO11HuarDk5M6BQcnkvY sGKMsqSNp7znMCbMYPNNOHTd658UnZErktpdvvQczAvBPZNGQWNZLMlAt8K2+Q+Ezwyg KlHSrVyii0d+wk7yisQMA2kX5zFWv/y2Tp3AGFe7Rexm7UqWJiXQL6bICzG7n0fNYwCw 9fcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686678014; x=1689270014; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=4kUJW+8FaqLzgttrJyg1cSLzKp0rVov2HBJYZBKRSbA=; b=gPfAspxfzkSiaNXRLw8PN2Pk9A4Ex1Je9PJoRhU6SYBrIkTcpEQT1To1EsJzU/vTVI b7SIEa3h8kqOqov52d2I28mwIi1o9dCMMMPvu3hBxQ2gDItv8/1F4wboyLGiahqtCXMe by2xR3nln+f1oyQidf60FvUCvLVSpK38WGYp+XAoBXmzryhX+iSBJCqu8pP/cxUzBadv vA1pxAoM3VHJUSjMNGIkhvOEaus9hs23rNVKGGJOQR/B3ajFPS237RpjA59LWtzwigS6 l7Y5Z0iUMqMAGjy/XwGwxAAXn02ksndzzCfPO8nu1sQbLcc0W6K5ny98NQUbMO7OnNbo t3Wg== X-Gm-Message-State: AC+VfDwxDXsZ3n89rqL3U+FqqkCOlKhWwXs2HPzFFQljm5qgdLUq42/r oMQGd4NNfhYKBdzYiBdn7tQ9V7L5o4YUKhMBijMedI1GPE9lEDB2TQa/htCFlAmJhin0Gk8eyL4 stZZhQmFPmm6XAeSwOtR5Or9U6x1anUvhEihU8RUhNRVsblATvbI/ADaWiW47rIEzCha6ce/Ek+ 00 X-Google-Smtp-Source: ACHHUZ6i8zSv5F24jm/JOCHglnrwYTbNWzjnG9x+CIingp+a3v9lGE/fC9jhGwrAx9EjApN9h9JpPOwXLJDgIqngryVR X-Received: from jonathantanmy0.svl.corp.google.com ([2620:15c:2d3:202:5e39:4d58:c992:1db0]) (user=jonathantanmy job=sendgmr) by 2002:a81:a8c6:0:b0:56d:21a1:16a1 with SMTP id f189-20020a81a8c6000000b0056d21a116a1mr1068592ywh.5.1686678014434; Tue, 13 Jun 2023 10:40:14 -0700 (PDT) Date: Tue, 13 Jun 2023 10:39:57 -0700 In-Reply-To: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-goog Message-ID: <6adfa53dafc8c34f94a017fdc08460911f53d310.1686677910.git.jonathantanmy@google.com> Subject: [PATCH v4 3/4] repo-settings: introduce commitgraph.changedPathsVersion From: Jonathan Tan To: git@vger.kernel.org Cc: Jonathan Tan , Ramsay Jones , Junio C Hamano Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org A subsequent commit will introduce another version of the changed-path filter in the commit graph file. In order to control which version is to be accepted when read (and which version to write), a config variable is needed. Therefore, introduce this config variable. For forwards compatibility, teach Git to not read commit graphs when the config variable is set to an unsupported version. Because we teach Git this, commitgraph.readChangedPaths is now redundant, so deprecate it and define its behavior in terms of the config variable we introduce. This commit does not change the behavior of writing (Git writes changed path filters when explicitly instructed regardless of any config variable), but a subsequent commit will restrict Git such that it will only write when commitgraph.changedPathsVersion is 0, 1, or 2. Signed-off-by: Jonathan Tan Signed-off-by: Junio C Hamano --- Documentation/config/commitgraph.txt | 16 +++++++++++++--- commit-graph.c | 2 +- oss-fuzz/fuzz-commit-graph.c | 2 +- repo-settings.c | 6 +++++- repository.h | 2 +- 5 files changed, 21 insertions(+), 7 deletions(-) diff --git a/Documentation/config/commitgraph.txt b/Documentation/config/commitgraph.txt index 30604e4a4c..eaa10bf232 100644 --- a/Documentation/config/commitgraph.txt +++ b/Documentation/config/commitgraph.txt @@ -9,6 +9,16 @@ commitGraph.maxNewFilters:: commit-graph write` (c.f., linkgit:git-commit-graph[1]). commitGraph.readChangedPaths:: - If true, then git will use the changed-path Bloom filters in the - commit-graph file (if it exists, and they are present). Defaults to - true. See linkgit:git-commit-graph[1] for more information. + Deprecated. Equivalent to changedPathsVersion=1 if true, and + changedPathsVersion=0 if false. + +commitGraph.changedPathsVersion:: + Specifies the version of the changed-path Bloom filters that Git will read and + write. May be 0 or 1. Any changed-path Bloom filters on disk that do not + match the version set in this config variable will be ignored. ++ +Defaults to 1. ++ +If 0, git will write version 1 Bloom filters when instructed to write. ++ +See linkgit:git-commit-graph[1] for more information. diff --git a/commit-graph.c b/commit-graph.c index c11b59f28b..bd448047f1 100644 --- a/commit-graph.c +++ b/commit-graph.c @@ -399,7 +399,7 @@ struct commit_graph *parse_commit_graph(struct repo_settings *s, graph->read_generation_data = 1; } - if (s->commit_graph_read_changed_paths) { + if (s->commit_graph_changed_paths_version == 1) { pair_chunk(cf, GRAPH_CHUNKID_BLOOMINDEXES, &graph->chunk_bloom_indexes); read_chunk(cf, GRAPH_CHUNKID_BLOOMDATA, diff --git a/oss-fuzz/fuzz-commit-graph.c b/oss-fuzz/fuzz-commit-graph.c index 914026f5d8..b56731f51a 100644 --- a/oss-fuzz/fuzz-commit-graph.c +++ b/oss-fuzz/fuzz-commit-graph.c @@ -18,7 +18,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) * possible. */ the_repository->settings.commit_graph_generation_version = 2; - the_repository->settings.commit_graph_read_changed_paths = 1; + the_repository->settings.commit_graph_changed_paths_version = 1; g = parse_commit_graph(&the_repository->settings, (void *)data, size); repo_clear(the_repository); free_commit_graph(g); diff --git a/repo-settings.c b/repo-settings.c index 3dbd3f0e2e..6cbe02681b 100644 --- a/repo-settings.c +++ b/repo-settings.c @@ -24,6 +24,7 @@ void prepare_repo_settings(struct repository *r) int value; const char *strval; int manyfiles; + int readChangedPaths; if (!r->gitdir) BUG("Cannot add settings for uninitialized repository"); @@ -54,7 +55,10 @@ void prepare_repo_settings(struct repository *r) /* Commit graph config or default, does not cascade (simple) */ repo_cfg_bool(r, "core.commitgraph", &r->settings.core_commit_graph, 1); repo_cfg_int(r, "commitgraph.generationversion", &r->settings.commit_graph_generation_version, 2); - repo_cfg_bool(r, "commitgraph.readchangedpaths", &r->settings.commit_graph_read_changed_paths, 1); + repo_cfg_bool(r, "commitgraph.readchangedpaths", &readChangedPaths, 1); + repo_cfg_int(r, "commitgraph.changedpathsversion", + &r->settings.commit_graph_changed_paths_version, + readChangedPaths ? 1 : 0); repo_cfg_bool(r, "gc.writecommitgraph", &r->settings.gc_write_commit_graph, 1); repo_cfg_bool(r, "fetch.writecommitgraph", &r->settings.fetch_write_commit_graph, 0); diff --git a/repository.h b/repository.h index e8c67ffe16..1f1c32a6dd 100644 --- a/repository.h +++ b/repository.h @@ -32,7 +32,7 @@ struct repo_settings { int core_commit_graph; int commit_graph_generation_version; - int commit_graph_read_changed_paths; + int commit_graph_changed_paths_version; int gc_write_commit_graph; int gc_cruft_packs; int fetch_write_commit_graph; From patchwork Tue Jun 13 17:39:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Tan X-Patchwork-Id: 13279111 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 B28E2EB64D8 for ; Tue, 13 Jun 2023 17:40:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239794AbjFMRk3 (ORCPT ); Tue, 13 Jun 2023 13:40:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240228AbjFMRkT (ORCPT ); Tue, 13 Jun 2023 13:40:19 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F241E6 for ; Tue, 13 Jun 2023 10:40:17 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-bd69ee0edacso382265276.3 for ; Tue, 13 Jun 2023 10:40:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1686678016; x=1689270016; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=nAGbYSsMeFfMcs+GTWkdAk0trIdhA9a/gAXYzLJkSL4=; b=YfNakzUH1muP0SVQCprv+9Pwa6CmtLHrzxLKtte0OIwZRMaWaY0ZE1+VlT9rYXuQkk kmg57R3Fv2fexbXBJVgjkuA5Z2c7o1p3gyvUWc06hUxcoh3Dc80ZH7fcMZnmxUJ8r3Xv 8nxI7Z+3AZuaPchtjicRXYPNrgRYUoWT9onCePe1hVGkDmOEKUZvTcGXw2BpIj4jfrWd QHu7yJ6t21s7rOQvH/fSAS3gwK3XXIeFpkh8EbwrjewCF4bNwMwEpoMcNoujDJn/DlS0 g295PDPzia8/smjzqievnHfYTCPJqEj8v3vEatWQmV1vzhMgpopf0urONzw92R2aXhTd yb3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686678016; x=1689270016; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=nAGbYSsMeFfMcs+GTWkdAk0trIdhA9a/gAXYzLJkSL4=; b=UpEDa0jy93uUiqhGf0GG12clvtJ/1MI7JwhCaPtugI92t0q8R8o845heIkzVRyTqQv 6uz1jGlxqqbt3wdIg+jm/wEgoZpGSccNCn6AthW1eBKOt4ua0ifNJqHqjYgVr7K+u3UV splbgRtkGDyWbTALGXCUap6A237X52sWv4C5DL/t3UGIHVoM1qKj/+kbk51ZyJu2bXpX l4ENi7jz9VIeV3Ta+ThYqFzKXPUBlfMdrgJmMTsAa8nFo4m0R0/q5oBb0+QP4Vc6e9Na rQ6x14t+hz009NB6clsaPcFbAPgFIYMuKFlRAfaDpI/bPtRwqhIyu5LQL3215lAJyMGn irLg== X-Gm-Message-State: AC+VfDy7QZY4FD8uPhovJ9XzOAJiTH7fXxnBHBZqmmhphet3YWTLMJsY WD6O3U05soF8L/Y1urYdRT831Yd9PkcMGyVi5g/XJOoyovmKeyXpOxWoys8WUVtoVIbmJDguemk HI98XkJACjhkGbFPHs0Ix7MKUVvUK1UUPUTIHv4w2AcnK11q6A+1zPHXeTej2c7tW/8/TW9+j/o Gg X-Google-Smtp-Source: ACHHUZ5svb8mNyJ1S2NgeCYg5RXU6WhiwbKT5JWTTorH9dgTSBjGxTmDBLmzJ+6SqbQkfOKaOfYaUdjewRNhqQutRddd X-Received: from jonathantanmy0.svl.corp.google.com ([2620:15c:2d3:202:5e39:4d58:c992:1db0]) (user=jonathantanmy job=sendgmr) by 2002:a05:6902:1384:b0:bca:295e:f9bf with SMTP id x4-20020a056902138400b00bca295ef9bfmr1060309ybu.7.1686678016647; Tue, 13 Jun 2023 10:40:16 -0700 (PDT) Date: Tue, 13 Jun 2023 10:39:58 -0700 In-Reply-To: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-goog Message-ID: <5c65bf8a22d657c58b1109928b4298e95ccb56bf.1686677910.git.jonathantanmy@google.com> Subject: [PATCH v4 4/4] commit-graph: new filter ver. that fixes murmur3 From: Jonathan Tan To: git@vger.kernel.org Cc: Jonathan Tan , Ramsay Jones , Junio C Hamano Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org The murmur3 implementation in bloom.c has a bug when converting series of 4 bytes into network-order integers when char is signed (which is controllable by a compiler option, and the default signedness of char is platform-specific). When a string contains characters with the high bit set, this bug causes results that, although internally consistent within Git, does not accord with other implementations of murmur3 and even with Git binaries that were compiled with different signedness of char. This bug affects both how Git writes changed path filters to disk and how Git interprets changed path filters on disk. Therefore, introduce a new version (2) of changed path filters that corrects this problem. The existing version (1) is still supported and is still the default, but users should migrate away from it as soon as possible. Because this bug only manifests with characters that have the high bit set, it may be possible that some (or all) commits in a given repo would have the same changed path filter both before and after this fix is applied. However, in order to determine whether this is the case, the changed paths would first have to be computed, at which point it is not much more expensive to just compute a new changed path filter. So this patch does not include any mechanism to "salvage" changed path filters from repositories. There is also no "mixed" mode - for each invocation of Git, reading and writing changed path filters are done with the same version number. There is a change in write_commit_graph(). graph_read_bloom_data() makes it possible for chunk_bloom_data to be non-NULL but bloom_filter_settings to be NULL, which causes a segfault later on. I produced such a segfault while developing this patch, but couldn't find a way to reproduce it neither after this complete patch (or before), but in any case it seemed like a good thing to include that might help future patch authors. The value in t0095 was obtained from another murmur3 implementation using the following Go source code: package main import "fmt" import "github.com/spaolacci/murmur3" func main() { fmt.Printf("%x\n", murmur3.Sum32([]byte("Hello world!"))) fmt.Printf("%x\n", murmur3.Sum32([]byte{0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff})) } Signed-off-by: Jonathan Tan Signed-off-by: Junio C Hamano --- Documentation/config/commitgraph.txt | 2 +- bloom.c | 65 ++++++++++++++++++++++++++-- bloom.h | 8 ++-- commit-graph.c | 29 ++++++++++--- t/helper/test-bloom.c | 9 +++- t/t0095-bloom.sh | 8 ++++ t/t4216-log-bloom.sh | 31 +++++++++++++ 7 files changed, 139 insertions(+), 13 deletions(-) diff --git a/Documentation/config/commitgraph.txt b/Documentation/config/commitgraph.txt index eaa10bf232..c64ee4f459 100644 --- a/Documentation/config/commitgraph.txt +++ b/Documentation/config/commitgraph.txt @@ -14,7 +14,7 @@ commitGraph.readChangedPaths:: commitGraph.changedPathsVersion:: Specifies the version of the changed-path Bloom filters that Git will read and - write. May be 0 or 1. Any changed-path Bloom filters on disk that do not + write. May be 0, 1, or 2. Any changed-path Bloom filters on disk that do not match the version set in this config variable will be ignored. + Defaults to 1. diff --git a/bloom.c b/bloom.c index d0730525da..915d8e5a31 100644 --- a/bloom.c +++ b/bloom.c @@ -65,7 +65,64 @@ static int load_bloom_filter_from_graph(struct commit_graph *g, * Not considered to be cryptographically secure. * Implemented as described in https://en.wikipedia.org/wiki/MurmurHash#Algorithm */ -uint32_t murmur3_seeded(uint32_t seed, const char *data, size_t len) +uint32_t murmur3_seeded_v2(uint32_t seed, const char *data, size_t len) +{ + const uint32_t c1 = 0xcc9e2d51; + const uint32_t c2 = 0x1b873593; + const uint32_t r1 = 15; + const uint32_t r2 = 13; + const uint32_t m = 5; + const uint32_t n = 0xe6546b64; + int i; + uint32_t k1 = 0; + const char *tail; + + int len4 = len / sizeof(uint32_t); + + uint32_t k; + for (i = 0; i < len4; i++) { + uint32_t byte1 = (uint32_t)(unsigned char)data[4*i]; + uint32_t byte2 = ((uint32_t)(unsigned char)data[4*i + 1]) << 8; + uint32_t byte3 = ((uint32_t)(unsigned char)data[4*i + 2]) << 16; + uint32_t byte4 = ((uint32_t)(unsigned char)data[4*i + 3]) << 24; + k = byte1 | byte2 | byte3 | byte4; + k *= c1; + k = rotate_left(k, r1); + k *= c2; + + seed ^= k; + seed = rotate_left(seed, r2) * m + n; + } + + tail = (data + len4 * sizeof(uint32_t)); + + switch (len & (sizeof(uint32_t) - 1)) { + case 3: + k1 ^= ((uint32_t)(unsigned char)tail[2]) << 16; + /*-fallthrough*/ + case 2: + k1 ^= ((uint32_t)(unsigned char)tail[1]) << 8; + /*-fallthrough*/ + case 1: + k1 ^= ((uint32_t)(unsigned char)tail[0]) << 0; + k1 *= c1; + k1 = rotate_left(k1, r1); + k1 *= c2; + seed ^= k1; + break; + } + + seed ^= (uint32_t)len; + seed ^= (seed >> 16); + seed *= 0x85ebca6b; + seed ^= (seed >> 13); + seed *= 0xc2b2ae35; + seed ^= (seed >> 16); + + return seed; +} + +static uint32_t murmur3_seeded_v1(uint32_t seed, const char *data, size_t len) { const uint32_t c1 = 0xcc9e2d51; const uint32_t c2 = 0x1b873593; @@ -130,8 +187,10 @@ void fill_bloom_key(const char *data, int i; const uint32_t seed0 = 0x293ae76f; const uint32_t seed1 = 0x7e646e2c; - const uint32_t hash0 = murmur3_seeded(seed0, data, len); - const uint32_t hash1 = murmur3_seeded(seed1, data, len); + const uint32_t hash0 = (settings->hash_version == 2 + ? murmur3_seeded_v2 : murmur3_seeded_v1)(seed0, data, len); + const uint32_t hash1 = (settings->hash_version == 2 + ? murmur3_seeded_v2 : murmur3_seeded_v1)(seed1, data, len); key->hashes = (uint32_t *)xcalloc(settings->num_hashes, sizeof(uint32_t)); for (i = 0; i < settings->num_hashes; i++) diff --git a/bloom.h b/bloom.h index adde6dfe21..0c33ae282c 100644 --- a/bloom.h +++ b/bloom.h @@ -7,9 +7,11 @@ struct repository; struct bloom_filter_settings { /* * The version of the hashing technique being used. - * We currently only support version = 1 which is + * The newest version is 2, which is * the seeded murmur3 hashing technique implemented - * in bloom.c. + * in bloom.c. Bloom filters of version 1 were created + * with prior versions of Git, which had a bug in the + * implementation of the hash function. */ uint32_t hash_version; @@ -75,7 +77,7 @@ struct bloom_key { * Not considered to be cryptographically secure. * Implemented as described in https://en.wikipedia.org/wiki/MurmurHash#Algorithm */ -uint32_t murmur3_seeded(uint32_t seed, const char *data, size_t len); +uint32_t murmur3_seeded_v2(uint32_t seed, const char *data, size_t len); void fill_bloom_key(const char *data, size_t len, diff --git a/commit-graph.c b/commit-graph.c index bd448047f1..36e6d09e74 100644 --- a/commit-graph.c +++ b/commit-graph.c @@ -302,15 +302,21 @@ static int graph_read_oid_lookup(const unsigned char *chunk_start, return 0; } +struct graph_read_bloom_data_data { + struct commit_graph *g; + int commit_graph_changed_paths_version; +}; + static int graph_read_bloom_data(const unsigned char *chunk_start, size_t chunk_size, void *data) { - struct commit_graph *g = data; + struct graph_read_bloom_data_data *d = data; + struct commit_graph *g = d->g; uint32_t hash_version; g->chunk_bloom_data = chunk_start; hash_version = get_be32(chunk_start); - if (hash_version != 1) + if (hash_version != d->commit_graph_changed_paths_version) return 0; g->bloom_filter_settings = xmalloc(sizeof(struct bloom_filter_settings)); @@ -399,11 +405,16 @@ struct commit_graph *parse_commit_graph(struct repo_settings *s, graph->read_generation_data = 1; } - if (s->commit_graph_changed_paths_version == 1) { + if (s->commit_graph_changed_paths_version == 1 + || s->commit_graph_changed_paths_version == 2) { + struct graph_read_bloom_data_data data = { + .g = graph, + .commit_graph_changed_paths_version = s->commit_graph_changed_paths_version + }; pair_chunk(cf, GRAPH_CHUNKID_BLOOMINDEXES, &graph->chunk_bloom_indexes); read_chunk(cf, GRAPH_CHUNKID_BLOOMDATA, - graph_read_bloom_data, graph); + graph_read_bloom_data, &data); } if (graph->chunk_bloom_indexes && graph->chunk_bloom_data) { @@ -2302,6 +2313,14 @@ int write_commit_graph(struct object_directory *odb, ctx->write_generation_data = (get_configured_generation_version(r) == 2); ctx->num_generation_data_overflows = 0; + if (r->settings.commit_graph_changed_paths_version < 0 + || r->settings.commit_graph_changed_paths_version > 2) { + warning(_("attempting to write a commit-graph, but 'commitgraph.changedPathsVersion' (%d) is not supported"), + r->settings.commit_graph_changed_paths_version); + return 0; + } + bloom_settings.hash_version = r->settings.commit_graph_changed_paths_version == 2 + ? 2 : 1; bloom_settings.bits_per_entry = git_env_ulong("GIT_TEST_BLOOM_SETTINGS_BITS_PER_ENTRY", bloom_settings.bits_per_entry); bloom_settings.num_hashes = git_env_ulong("GIT_TEST_BLOOM_SETTINGS_NUM_HASHES", @@ -2331,7 +2350,7 @@ int write_commit_graph(struct object_directory *odb, g = ctx->r->objects->commit_graph; /* We have changed-paths already. Keep them in the next graph */ - if (g && g->chunk_bloom_data) { + if (g && g->bloom_filter_settings) { ctx->changed_paths = 1; ctx->bloom_settings = g->bloom_filter_settings; } diff --git a/t/helper/test-bloom.c b/t/helper/test-bloom.c index 6c900ca668..34b8dd9164 100644 --- a/t/helper/test-bloom.c +++ b/t/helper/test-bloom.c @@ -48,6 +48,7 @@ static void get_bloom_filter_for_commit(const struct object_id *commit_oid) static const char *bloom_usage = "\n" " test-tool bloom get_murmur3 \n" +" test-tool bloom get_murmur3_seven_highbit\n" " test-tool bloom generate_filter [...]\n" " test-tool bloom get_filter_for_commit \n"; @@ -62,7 +63,13 @@ int cmd__bloom(int argc, const char **argv) uint32_t hashed; if (argc < 3) usage(bloom_usage); - hashed = murmur3_seeded(0, argv[2], strlen(argv[2])); + hashed = murmur3_seeded_v2(0, argv[2], strlen(argv[2])); + printf("Murmur3 Hash with seed=0:0x%08x\n", hashed); + } + + if (!strcmp(argv[1], "get_murmur3_seven_highbit")) { + uint32_t hashed; + hashed = murmur3_seeded_v2(0, "\x99\xaa\xbb\xcc\xdd\xee\xff", 7); printf("Murmur3 Hash with seed=0:0x%08x\n", hashed); } diff --git a/t/t0095-bloom.sh b/t/t0095-bloom.sh index b567383eb8..c8d84ab606 100755 --- a/t/t0095-bloom.sh +++ b/t/t0095-bloom.sh @@ -29,6 +29,14 @@ test_expect_success 'compute unseeded murmur3 hash for test string 2' ' test_cmp expect actual ' +test_expect_success 'compute unseeded murmur3 hash for test string 3' ' + cat >expect <<-\EOF && + Murmur3 Hash with seed=0:0xa183ccfd + EOF + test-tool bloom get_murmur3_seven_highbit >actual && + test_cmp expect actual +' + test_expect_success 'compute bloom key for empty string' ' cat >expect <<-\EOF && Hashes:0x5615800c|0x5b966560|0x61174ab4|0x66983008|0x6c19155c|0x7199fab0|0x771ae004| diff --git a/t/t4216-log-bloom.sh b/t/t4216-log-bloom.sh index baa0c48897..5cb35c3a3e 100755 --- a/t/t4216-log-bloom.sh +++ b/t/t4216-log-bloom.sh @@ -450,4 +450,35 @@ test_expect_success 'version 1 changed-path used when version 1 requested' ' test_bloom_filters_used "-- $CENT") ' +test_expect_success 'version 1 changed-path not used when version 2 requested' ' + (cd highbit1 && + git config --add commitgraph.changedPathsVersion 2 && + test_bloom_filters_not_used "-- $CENT") +' + +test_expect_success 'set up repo with high bit path, version 2 changed-path' ' + git init highbit2 && + git -C highbit2 config --add commitgraph.changedPathsVersion 2 && + test_commit -C highbit2 c2 "$CENT" && + git -C highbit2 commit-graph write --reachable --changed-paths +' + +test_expect_success 'check value of version 2 changed-path' ' + (cd highbit2 && + printf "c01f" >expect && + get_first_changed_path_filter >actual && + test_cmp expect actual) +' + +test_expect_success 'version 2 changed-path used when version 2 requested' ' + (cd highbit2 && + test_bloom_filters_used "-- $CENT") +' + +test_expect_success 'version 2 changed-path not used when version 1 requested' ' + (cd highbit2 && + git config --add commitgraph.changedPathsVersion 1 && + test_bloom_filters_not_used "-- $CENT") +' + test_done