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-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 5415E1F66F for ; Fri, 4 Sep 2020 13:10:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730401AbgIDNJx (ORCPT ); Fri, 4 Sep 2020 09:09:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47832 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730362AbgIDNJX (ORCPT ); Fri, 4 Sep 2020 09:09:23 -0400 Received: from mail-wr1-x442.google.com (mail-wr1-x442.google.com [IPv6:2a00:1450:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9A15C061244 for ; Fri, 4 Sep 2020 06:09:22 -0700 (PDT) Received: by mail-wr1-x442.google.com with SMTP id k15so6669723wrn.10 for ; Fri, 04 Sep 2020 06:09:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=DYDzdATbEtsle88tIWHcnPVQI2YF/b2jAlzqwzreowg=; b=RJcUpyhjqlQV8Ia+RZeN/IVVO5Pi3ZZo9HY+WHHeXboSa9LJXmwDDkV3X8kegXv1NN gAOrd3ifPdelNsGZ+1bvVnK00VDDRCaP+5KuIpyhUN8vZQzcOevLae+g8VBFHmuBhLEn eantDuqXMgB1TJd2EBJThg+TEqDNIvfmC046Z2KNJYBcIAm1185SaxCgeg5jfAwuswY1 xFWWWw1V6Qo6QKA8sk4RV5VV4GfJPb7kzw5cF3DBbGoxj8T3LQvoY3J2XjQ7lFHvjxix qJZVUYd5S7m2mrYG3rf3ZjMn3wUFEuudjR5XqlW9KQXESrLeoPM5d+6Zd3uk3CX0eOj6 aXlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=DYDzdATbEtsle88tIWHcnPVQI2YF/b2jAlzqwzreowg=; b=TUBMuMVaa88rfajgS12GfVAF9qvfi9jZc+BBkOCgC1dua7PjhS4q1nv5/BN4Vxh5Ad 1xXazwb79TaIXobf3bLMQJo69YW30Txo85fk1RBFhNOd2+ee95vadTygj1xbPVWSZ9Xj sbbDZCKQrW389BSXUAK7P2BeXyHiPvKbqnxjtxC6WidP+AiGvuT8KZxj+H57E0m7z/Bw e30tGv7e1SOMjLh/C2LuTBw6XuWvm/LH67DH8ulVQv4tG+FKaDuz8m/6VSHkDV4rGBeo VVzOACXrKsSJthAW6vk73Fdg6XwaL0By6qTVBnzCCmqVm9bt1/YfPhiHEa5m3e2hAY5z dpBQ== X-Gm-Message-State: AOAM532w1Gr4Ed1QultVPwHQq8HnVf5yWUeJ5+DmP3vhaPaow/rxVeMe nzTknP4XYLE/sOY65exO5zpdWfkY3Hw= X-Google-Smtp-Source: ABdhPJxZgdA9EWp0Zqfl727zYC73S0vCVT4B1v9dTKCiL5hZMLu6nUMprBJsVrIxOW4bRl8II0ADng== X-Received: by 2002:a5d:4246:: with SMTP id s6mr7322021wrr.414.1599224961367; Fri, 04 Sep 2020 06:09:21 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id f3sm11166185wmb.35.2020.09.04.06.09.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Sep 2020 06:09:20 -0700 (PDT) Message-Id: <06984a42bfc892b82f7b39a1aa366158fcf3fd20.1599224956.git.gitgitgadget@gmail.com> In-Reply-To: References: From: "Derrick Stolee via GitGitGadget" Date: Fri, 04 Sep 2020 13:09:09 +0000 Subject: [PATCH v4 05/11] maintenance: add commit-graph task Fcc: Sent Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 To: git@vger.kernel.org Cc: Jonathan Tan , Derrick Stolee , Derrick Stolee Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Derrick Stolee The first new task in the 'git maintenance' builtin is the 'commit-graph' task. This updates the commit-graph file incrementally with the command git commit-graph write --reachable --split By writing an incremental commit-graph file using the "--split" option we minimize the disruption from this operation. The default behavior is to merge layers until the new "top" layer is less than half the size of the layer below. This provides quick writes most of the time, with the longer writes following a power law distribution. Most importantly, concurrent Git processes only look at the commit-graph-chain file for a very short amount of time, so they will verly likely not be holding a handle to the file when we try to replace it. (This only matters on Windows.) If a concurrent process reads the old commit-graph-chain file, but our job expires some of the .graph files before they can be read, then those processes will see a warning message (but not fail). This could be avoided by a future update to use the --expire-time argument when writing the commit-graph. Signed-off-by: Derrick Stolee --- Documentation/git-maintenance.txt | 8 ++++++++ builtin/gc.c | 30 ++++++++++++++++++++++++++++++ commit-graph.c | 8 ++++---- commit-graph.h | 1 + t/t7900-maintenance.sh | 2 ++ 5 files changed, 45 insertions(+), 4 deletions(-) diff --git a/Documentation/git-maintenance.txt b/Documentation/git-maintenance.txt index 04fa0fe329..fc5dbcf0b9 100644 --- a/Documentation/git-maintenance.txt +++ b/Documentation/git-maintenance.txt @@ -35,6 +35,14 @@ run:: TASKS ----- +commit-graph:: + The `commit-graph` job updates the `commit-graph` files incrementally, + then verifies that the written data is correct. The incremental + write is safe to run alongside concurrent Git processes since it + will not expire `.graph` files that were in the previous + `commit-graph-chain` file. They will be deleted by a later run based + on the expiration delay. + gc:: Clean up unnecessary files and optimize the local repository. "GC" stands for "garbage collection," but this task performs many diff --git a/builtin/gc.c b/builtin/gc.c index 81643515e5..16e567992e 100644 --- a/builtin/gc.c +++ b/builtin/gc.c @@ -710,6 +710,31 @@ struct maintenance_run_opts { int quiet; }; +static int run_write_commit_graph(struct maintenance_run_opts *opts) +{ + struct child_process child = CHILD_PROCESS_INIT; + + child.git_cmd = 1; + strvec_pushl(&child.args, "commit-graph", "write", + "--split", "--reachable", NULL); + + if (opts->quiet) + strvec_push(&child.args, "--no-progress"); + + return !!run_command(&child); +} + +static int maintenance_task_commit_graph(struct maintenance_run_opts *opts) +{ + close_object_store(the_repository->objects); + if (run_write_commit_graph(opts)) { + error(_("failed to write commit-graph")); + return 1; + } + + return 0; +} + static int maintenance_task_gc(struct maintenance_run_opts *opts) { struct child_process child = CHILD_PROCESS_INIT; @@ -738,6 +763,7 @@ struct maintenance_task { enum maintenance_task_label { TASK_GC, + TASK_COMMIT_GRAPH, /* Leave as final value */ TASK__COUNT @@ -749,6 +775,10 @@ static struct maintenance_task tasks[] = { maintenance_task_gc, 1, }, + [TASK_COMMIT_GRAPH] = { + "commit-graph", + maintenance_task_commit_graph, + }, }; static int maintenance_run_tasks(struct maintenance_run_opts *opts) diff --git a/commit-graph.c b/commit-graph.c index e51c91dd5b..a9b0db7d4a 100644 --- a/commit-graph.c +++ b/commit-graph.c @@ -172,7 +172,7 @@ static char *get_split_graph_filename(struct object_directory *odb, oid_hex); } -static char *get_chain_filename(struct object_directory *odb) +char *get_commit_graph_chain_filename(struct object_directory *odb) { return xstrfmt("%s/info/commit-graphs/commit-graph-chain", odb->path); } @@ -516,7 +516,7 @@ static struct commit_graph *load_commit_graph_chain(struct repository *r, struct stat st; struct object_id *oids; int i = 0, valid = 1, count; - char *chain_name = get_chain_filename(odb); + char *chain_name = get_commit_graph_chain_filename(odb); FILE *fp; int stat_res; @@ -1668,7 +1668,7 @@ static int write_commit_graph_file(struct write_commit_graph_context *ctx) } if (ctx->split) { - char *lock_name = get_chain_filename(ctx->odb); + char *lock_name = get_commit_graph_chain_filename(ctx->odb); hold_lock_file_for_update_mode(&lk, lock_name, LOCK_DIE_ON_ERROR, 0444); @@ -2038,7 +2038,7 @@ static void expire_commit_graphs(struct write_commit_graph_context *ctx) if (ctx->split_opts && ctx->split_opts->expire_time) expire_time = ctx->split_opts->expire_time; if (!ctx->split) { - char *chain_file_name = get_chain_filename(ctx->odb); + char *chain_file_name = get_commit_graph_chain_filename(ctx->odb); unlink(chain_file_name); free(chain_file_name); ctx->num_commit_graphs_after = 0; diff --git a/commit-graph.h b/commit-graph.h index 09a97030dc..765221cdcc 100644 --- a/commit-graph.h +++ b/commit-graph.h @@ -25,6 +25,7 @@ struct raw_object_store; struct string_list; char *get_commit_graph_filename(struct object_directory *odb); +char *get_commit_graph_chain_filename(struct object_directory *odb); int open_commit_graph(const char *graph_file, int *fd, struct stat *st); /* diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh index 47d512464c..c0c4e6846e 100755 --- a/t/t7900-maintenance.sh +++ b/t/t7900-maintenance.sh @@ -4,6 +4,8 @@ test_description='git maintenance builtin' . ./test-lib.sh +GIT_TEST_COMMIT_GRAPH=0 + test_expect_success 'help text' ' test_expect_code 129 git maintenance -h 2>err && test_i18ngrep "usage: git maintenance run" err && -- gitgitgadget