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=-3.7 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 C50C41FF9C for ; Tue, 27 Oct 2020 02:08:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2504370AbgJ0CIV (ORCPT ); Mon, 26 Oct 2020 22:08:21 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:44168 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2504360AbgJ0CIR (ORCPT ); Mon, 26 Oct 2020 22:08:17 -0400 Received: by mail-wr1-f66.google.com with SMTP id t9so60844wrq.11 for ; Mon, 26 Oct 2020 19:08:15 -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=TH48QvsASDnw6z3srdOANPLKrfrUD8Jg9GxDKDN5xG0=; b=f65Is3Dnzy2Ec9MiQ+u9cCLQIWWj0Kky2PWwEV/uSG7bV1JmCT7EQGsaup/pAv1i3q NQKoMdRzh/Iu/WHv40dYar6cnV0ccQlGCAd3clOYaTRqIqje4nvAqY2cY76Myzr7xJWS gPGEgcah18hvntqa2olCkwoYK+P1KGgkVYnzF4iL6DYnLay9yJRyv7Y8AV0oHBbFBtGn x7OptSOBM7eHGnkda49ZuSS/mD62uQqYAqjWQGI8/+N2nGo9dh9JjKayouw/H+oDpxao +8tPNy7MqH9kvWIHjZ8d+G3pVo3IRWe5GnPQoVT0z+y0VNBkycC/u8dZrvunvydLzQQV lT1w== 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=TH48QvsASDnw6z3srdOANPLKrfrUD8Jg9GxDKDN5xG0=; b=gLoOlKh8p51ZaRGLKa7nhLaK+nSjC9ncv4SLF4OTDlREWI+AoBa+3Pu7qDQXl2xNaE AmvOboppka9gOFbCJJkFNq/6haJS+xMLcnU42JX0V1nc+H2LSh0IAq2IAIulkEOtqIEw VQOukeYFerJa40XAJHOP74fKUaS2XFfqwm/QwqYtj6W+vAqCKJVqyHibdQQ1LLgBrQFS 2slwawIZ6qhL2WqaenTFjmCfkeIs77SkESmYXMNEXpWMnub2xiLAb8jU7F4fwRzFvI9r e3/zCYcnl6XJcd7gMds+amUalg6cp8JmvE2nxzKNds2YyP2kWelHzSz/LsnBV1TTnzX4 JBEQ== X-Gm-Message-State: AOAM532Quw69FwnkX2y0pT8nIdDQzWJb6WB/KAcwcNZWEA/w7ICN5XhB AF7wEvqlKyVsEt7n3sAbatBhc3EQ3qU= X-Google-Smtp-Source: ABdhPJznFlmqCw5BPOYLqNdgiWCFK6nruPbwsi8SGRWfFwvWt7I0KUxhuQSVPL/UDVahFYIjPTerAw== X-Received: by 2002:a5d:6110:: with SMTP id v16mr22447839wrt.219.1603764494300; Mon, 26 Oct 2020 19:08:14 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id y2sm26205653wrh.0.2020.10.26.19.08.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Oct 2020 19:08:13 -0700 (PDT) Message-Id: <27ad7566007676fc69dc28aa3b289547f0ccabca.1603764490.git.gitgitgadget@gmail.com> In-Reply-To: References: From: "Elijah Newren via GitGitGadget" Date: Tue, 27 Oct 2020 02:08:09 +0000 Subject: [PATCH v3 3/4] fast-rebase: demonstrate merge-ort's API via temporary/hidden command Fcc: Sent Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 To: git@vger.kernel.org Cc: Elijah Newren , Taylor Blau , Peter Baumann , Jonathan Tan , Elijah Newren , Elijah Newren Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Elijah Newren Add a special built-in that is only of use to git-developers and only during the development of merge-ort, and which is designed to immediately fail and print: git: 'fast-rebase' is not a git command unless a special GIT_TEST_MERGE_ALGORITHM environment variable is set. This special builtin serves two purposes: 1) Demonstrate the desired API of merge-ort. In particular, fast-rebase takes advantage of the separation of the merging operation from the updating of the index and working tree, to allow it to pick N commits, but only update the index and working tree once at the end. Look for the calls to merge_inmemory_nonrecursive() and merge_switch_to_result(). 2) Provide a convenient benchmark that isn't polluted by the heavy disk writing and forking of unnecessary processes that comes from sequencer.c and merge-recursive.c. fast-rebase is not meant to replace sequencer.c, just give ideas on how sequencer.c can be changed. Updating sequencer.c with these goals is probably a large amount of work; writing a simple targeted command with no documentation, less-than-useful help messages, numerous limitations in terms of flags it can accept and situations it can handle, and which is flagged off from users is a much easier interim step. Signed-off-by: Elijah Newren --- Makefile | 1 + builtin.h | 1 + builtin/fast-rebase.c | 210 ++++++++++++++++++++++++++++++++++++++++++ git.c | 1 + 4 files changed, 213 insertions(+) create mode 100644 builtin/fast-rebase.c diff --git a/Makefile b/Makefile index 382fe73c76..1b40d780fa 100644 --- a/Makefile +++ b/Makefile @@ -1087,6 +1087,7 @@ BUILTIN_OBJS += builtin/difftool.o BUILTIN_OBJS += builtin/env--helper.o BUILTIN_OBJS += builtin/fast-export.o BUILTIN_OBJS += builtin/fast-import.o +BUILTIN_OBJS += builtin/fast-rebase.o BUILTIN_OBJS += builtin/fetch-pack.o BUILTIN_OBJS += builtin/fetch.o BUILTIN_OBJS += builtin/fmt-merge-msg.o diff --git a/builtin.h b/builtin.h index 53fb290963..75ff7dc8a9 100644 --- a/builtin.h +++ b/builtin.h @@ -151,6 +151,7 @@ int cmd_difftool(int argc, const char **argv, const char *prefix); int cmd_env__helper(int argc, const char **argv, const char *prefix); int cmd_fast_export(int argc, const char **argv, const char *prefix); int cmd_fast_import(int argc, const char **argv, const char *prefix); +int cmd_fast_rebase(int argc, const char **argv, const char *prefix); int cmd_fetch(int argc, const char **argv, const char *prefix); int cmd_fetch_pack(int argc, const char **argv, const char *prefix); int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix); diff --git a/builtin/fast-rebase.c b/builtin/fast-rebase.c new file mode 100644 index 0000000000..b69632054f --- /dev/null +++ b/builtin/fast-rebase.c @@ -0,0 +1,210 @@ +/* + * "git fast-rebase" builtin command + * + * FAST: Forking Any Subprocesses (is) Taboo + * + * This is meant SOLELY as a demo of what is possible. sequencer.c and + * rebase.c should be refactored to use the ideas here, rather than attempting + * to extend this file to replace those (unless Phillip or Dscho say that + * refactoring is too hard and we need a clean slate, but I'm guessing that + * refactoring is the better route). + */ + +#define USE_THE_INDEX_COMPATIBILITY_MACROS +#include "builtin.h" + +#include "cache-tree.h" +#include "commit.h" +#include "lockfile.h" +#include "merge-ort.h" +#include "refs.h" +#include "revision.h" +#include "sequencer.h" +#include "strvec.h" +#include "tree.h" + +static const char *short_commit_name(struct commit *commit) +{ + return find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV); +} + +static struct commit *peel_committish(const char *name) +{ + struct object *obj; + struct object_id oid; + + if (get_oid(name, &oid)) + return NULL; + obj = parse_object(the_repository, &oid); + return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT); +} + +static char *get_author(const char *message) +{ + size_t len; + const char *a; + + a = find_commit_header(message, "author", &len); + if (a) + return xmemdupz(a, len); + + return NULL; +} + +static struct commit *create_commit(struct tree *tree, + struct commit *based_on, + struct commit *parent) +{ + struct object_id ret; + struct object *obj; + struct commit_list *parents = NULL; + char *author; + char *sign_commit = NULL; + struct commit_extra_header *extra; + struct strbuf msg = STRBUF_INIT; + const char *out_enc = get_commit_output_encoding(); + const char *message = logmsg_reencode(based_on, NULL, out_enc); + const char *orig_message = NULL; + const char *exclude_gpgsig[] = { "gpgsig", NULL }; + + commit_list_insert(parent, &parents); + extra = read_commit_extra_headers(based_on, exclude_gpgsig); + find_commit_subject(message, &orig_message); + strbuf_addstr(&msg, orig_message); + author = get_author(message); + reset_ident_date(); + if (commit_tree_extended(msg.buf, msg.len, &tree->object.oid, parents, + &ret, author, NULL, sign_commit, extra)) { + error(_("failed to write commit object")); + return NULL; + } + free(author); + strbuf_release(&msg); + + obj = parse_object(the_repository, &ret); + return (struct commit *)obj; +} + +int cmd_fast_rebase(int argc, const char **argv, const char *prefix) +{ + struct commit *onto; + struct commit *last_commit = NULL, *last_picked_commit = NULL; + struct object_id head; + struct lock_file lock = LOCK_INIT; + int clean = 1; + struct strvec rev_walk_args = STRVEC_INIT; + struct rev_info revs; + struct commit *commit; + struct merge_options merge_opt; + struct tree *next_tree, *base_tree, *head_tree; + struct merge_result result; + struct strbuf reflog_msg = STRBUF_INIT; + struct strbuf branch_name = STRBUF_INIT; + + if (argc == 2 && !strcmp(argv[1], "-h")) { + printf("Sorry, I am not a psychiatrist; I can not give you the help you need. Oh, you meant usage...\n"); + exit(129); + } + + if (!getenv("GIT_TEST_MERGE_ALGORITHM")) { + fprintf_ln(stderr, _("git: 'fast-rebase' is not a git command. See 'git --help'.")); + exit(1); + } + + if (argc != 5 || strcmp(argv[1], "--onto")) + die("usage: read the code, figure out how to use it, then do so"); + + onto = peel_committish(argv[2]); + strbuf_addf(&branch_name, "refs/heads/%s", argv[4]); + + /* Sanity check */ + if (get_oid("HEAD", &head)) + die(_("Cannot read HEAD")); + assert(oideq(&onto->object.oid, &head)); + + hold_locked_index(&lock, LOCK_DIE_ON_ERROR); + assert(repo_read_index(the_repository) >= 0); + + repo_init_revisions(the_repository, &revs, NULL); + revs.verbose_header = 1; + revs.max_parents = 1; + revs.cherry_mark = 1; + revs.limited = 1; + revs.reverse = 1; + revs.right_only = 1; + revs.sort_order = REV_SORT_IN_GRAPH_ORDER; + revs.topo_order = 1; + strvec_pushl(&rev_walk_args, "", argv[4], "--not", argv[3], NULL); + + if (setup_revisions(rev_walk_args.nr, rev_walk_args.v, &revs, NULL) > 1) + return error(_("unhandled options")); + + strvec_clear(&rev_walk_args); + + if (prepare_revision_walk(&revs) < 0) + return error(_("error preparing revisions")); + + init_merge_options(&merge_opt, the_repository); + memset(&result, 0, sizeof(result)); + merge_opt.show_rename_progress = 1; + merge_opt.branch1 = "HEAD"; + head_tree = get_commit_tree(onto); + result.tree = head_tree; + last_commit = onto; + while ((commit = get_revision(&revs))) { + struct commit *base; + + fprintf(stderr, "Rebasing %s...\r", + oid_to_hex(&commit->object.oid)); + assert(commit->parents && !commit->parents->next); + base = commit->parents->item; + + next_tree = get_commit_tree(commit); + base_tree = get_commit_tree(base); + + merge_opt.branch2 = short_commit_name(commit); + merge_opt.ancestor = xstrfmt("parent of %s", merge_opt.branch2); + + merge_incore_nonrecursive(&merge_opt, + base_tree, + result.tree, + next_tree, + &result); + + free((char*)merge_opt.ancestor); + merge_opt.ancestor = NULL; + if (!result.clean) + die("Aborting: Hit a conflict and restarting is not implemented."); + last_picked_commit = commit; + last_commit = create_commit(result.tree, commit, last_commit); + } + fprintf(stderr, "\nDone.\n"); + /* TODO: There should be some kind of rev_info_free(&revs) call... */ + memset(&revs, 0, sizeof(revs)); + + merge_switch_to_result(&merge_opt, head_tree, &result, 1, !result.clean); + + if (result.clean < 0) + exit(128); + + strbuf_addf(&reflog_msg, "finish rebase %s onto %s", + oid_to_hex(&last_picked_commit->object.oid), + oid_to_hex(&last_commit->object.oid)); + if (update_ref(reflog_msg.buf, branch_name.buf, + &last_commit->object.oid, + &last_picked_commit->object.oid, + REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR)) { + error(_("could not update %s"), argv[4]); + die("Failed to update %s", argv[4]); + } + if (create_symref("HEAD", branch_name.buf, reflog_msg.buf) < 0) + die(_("unable to update HEAD")); + strbuf_release(&reflog_msg); + strbuf_release(&branch_name); + + prime_cache_tree(the_repository, the_repository->index, result.tree); + if (write_locked_index(&the_index, &lock, + COMMIT_LOCK | SKIP_IF_UNCHANGED)) + die(_("unable to write %s"), get_index_file()); + return (clean == 0); +} diff --git a/git.c b/git.c index 4bdcdad2cc..af84f11e69 100644 --- a/git.c +++ b/git.c @@ -512,6 +512,7 @@ static struct cmd_struct commands[] = { { "env--helper", cmd_env__helper }, { "fast-export", cmd_fast_export, RUN_SETUP }, { "fast-import", cmd_fast_import, RUN_SETUP | NO_PARSEOPT }, + { "fast-rebase", cmd_fast_rebase, RUN_SETUP /* | NEED_WORK_TREE */ }, { "fetch", cmd_fetch, RUN_SETUP }, { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT }, { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP }, -- gitgitgadget