From patchwork Fri Feb 5 20:48:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Tan X-Patchwork-Id: 12070921 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A722C43381 for ; Fri, 5 Feb 2021 21:06:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02CC964FB7 for ; Fri, 5 Feb 2021 21:06:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232981AbhBETWr (ORCPT ); Fri, 5 Feb 2021 14:22:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233147AbhBETTD (ORCPT ); Fri, 5 Feb 2021 14:19:03 -0500 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE6D4C06178A for ; Fri, 5 Feb 2021 12:48:57 -0800 (PST) Received: by mail-pf1-x449.google.com with SMTP id b81so5824109pfb.21 for ; Fri, 05 Feb 2021 12:48:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=1CZZ7sT8txP4Clz45vTPXG4zpTbdFuBel09Ltu6XMkY=; b=S76y/E8o5M7aFV4VnwKc5ivMDwWmdScyC/Dbs1VOOnMGxbydunvKZDhmrovK4EnIAO Mr+FFde/7iWOA/y2I1j28H+iLNZ19bIp8rg0A5JqmvkNmX1MTgzua1YEZxyCoJziFWEA 8771UCLMB0QV0JzuxIExaOjsUByriw6KiM61FBw0dQgQM5LBv44/w8XxFlgjcVFnqH5Y t+w9S5j5ksiZWjKyC3aUP0g9IHIT8q/i+jZsehx4EmydgJdC6MhwxrnTjo/hGvd4U03e XPK873XhJ6rXYOwlFoTQO9uRS8Mwk6KPA54U2IPbHhgk+JnnbbqygAkGYps+UywTCAk3 X2aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=1CZZ7sT8txP4Clz45vTPXG4zpTbdFuBel09Ltu6XMkY=; b=Fv9W9ArddyjJGp48EcJ/T9dvrHXu2UjAKys5uaEGcrjSLiPU8LohPInEBRQB0UGJoP lFvjLYYjd9gXp+yZLwU/xngQXKGbWpsFAn4K3JZEYbV4MAFM+PHr1iYqZcdJNtQdqGNt msKj8ub37PPEQOYMPxDI4LSPiLT2I6N1WMjAhstqHtfGKA2ccDKMy8jiufS9VRKRdOpb KnG7xSv9RfkGgA0vAoomHOLVWeHhIE8agukZ4hEYfidZhDYmvlcJLKxTmvMc29iO/ohQ XniEACIPwNyqEw0DVMJ7KnYjrrpZlXWs2WUhryWDYXO9/9USoLhCeG15ugNZUcc3nZCx 41Bw== X-Gm-Message-State: AOAM532HR8liOaUuVeHDlP7jzM3jmK4p7Hp9kUGzESR337/PwF1I81bV 9hAXSBXHqeVqaVCk/fAl+lcTneVMDDq3dL+z8yOW8urYCCWpiu+f8vPbJ7XS0qcH1BG9uDPkHkQ SeMCZlucWe3uWDVwpvR0CG5+zXlifhJjgZ8UzvCjWbRD86p43DQowpd5zSwN3ZME1OqVIC6h0/6 xa X-Google-Smtp-Source: ABdhPJyonNvf/wykAZrjDtEr3dwuEfaoCfQpLn5Rp87UxSG+NLbq58fHqyhYfXeJbhwpEl8rP7hStbRxr7NuQX8Q0z/n Sender: "jonathantanmy via sendgmr" X-Received: from twelve4.c.googlers.com ([fda3:e722:ac3:10:24:72f4:c0a8:437a]) (user=jonathantanmy job=sendgmr) by 2002:a17:90a:644a:: with SMTP id y10mr6028915pjm.129.1612558134173; Fri, 05 Feb 2021 12:48:54 -0800 (PST) Date: Fri, 5 Feb 2021 12:48:47 -0800 In-Reply-To: Message-Id: <8b0f55b5e49e2a4e7bb2dc0cf3b9a4c96e03af32.1612557937.git.jonathantanmy@google.com> Mime-Version: 1.0 References: <20201208013121.677494-1-jonathantanmy@google.com> X-Mailer: git-send-email 2.30.0.365.g02bc693789-goog Subject: [PATCH v8 1/3] ls-refs: report unborn targets of symrefs From: Jonathan Tan To: git@vger.kernel.org Cc: Jonathan Tan , gitster@pobox.com, peff@peff.net Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org When cloning, we choose the default branch based on the remote HEAD. But if there is no remote HEAD reported (which could happen if the target of the remote HEAD is unborn), we'll fall back to using our local init.defaultBranch. Traditionally this hasn't been a big deal, because most repos used "master" as the default. But these days it is likely to cause confusion if the server and client implementations choose different values (e.g., if the remote started with "main", we may choose "master" locally, create commits there, and then the user is surprised when they push to "master" and not "main"). To solve this, the remote needs to communicate the target of the HEAD symref, even if it is unborn, and "git clone" needs to use this information. Currently, symrefs that have unborn targets (such as in this case) are not communicated by the protocol. Teach Git to advertise and support the "unborn" feature in "ls-refs" (by default, this is advertised, but server administrators may turn this off through the lsrefs.unborn config). This feature indicates that "ls-refs" supports the "unborn" argument; when it is specified, "ls-refs" will send the HEAD symref with the name of its unborn target. This change is only for protocol v2. A similar change for protocol v0 would require independent protocol design (there being no analogous position to signal support for "unborn") and client-side plumbing of the data required, so the scope of this patch set is limited to protocol v2. The client side will be updated to use this in a subsequent commit. Signed-off-by: Jonathan Tan Signed-off-by: Junio C Hamano --- Documentation/config.txt | 2 + Documentation/config/lsrefs.txt | 9 +++ Documentation/technical/protocol-v2.txt | 11 +++- ls-refs.c | 74 ++++++++++++++++++++++++- ls-refs.h | 1 + serve.c | 2 +- t/t5701-git-serve.sh | 2 +- 7 files changed, 95 insertions(+), 6 deletions(-) create mode 100644 Documentation/config/lsrefs.txt diff --git a/Documentation/config.txt b/Documentation/config.txt index 6ba50b1104..d08e83a148 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -398,6 +398,8 @@ include::config/interactive.txt[] include::config/log.txt[] +include::config/lsrefs.txt[] + include::config/mailinfo.txt[] include::config/mailmap.txt[] diff --git a/Documentation/config/lsrefs.txt b/Documentation/config/lsrefs.txt new file mode 100644 index 0000000000..adeda0f24d --- /dev/null +++ b/Documentation/config/lsrefs.txt @@ -0,0 +1,9 @@ +lsrefs.unborn:: + May be "advertise" (the default), "allow", or "ignore". If "advertise", + the server will respond to the client sending "unborn" (as described in + protocol-v2.txt) and will advertise support for this feature during the + protocol v2 capability advertisement. "allow" is the same as + "advertise" except that the server will not advertise support for this + feature; this is useful for load-balanced servers that cannot be + updated atomically (for example), since the administrator could + configure "allow", then after a delay, configure "advertise". diff --git a/Documentation/technical/protocol-v2.txt b/Documentation/technical/protocol-v2.txt index 85daeb5d9e..f772d90eaf 100644 --- a/Documentation/technical/protocol-v2.txt +++ b/Documentation/technical/protocol-v2.txt @@ -192,11 +192,20 @@ ls-refs takes in the following arguments: When specified, only references having a prefix matching one of the provided prefixes are displayed. +If the 'unborn' feature is advertised the following argument can be +included in the client's request. + + unborn + The server will send information about HEAD even if it is a symref + pointing to an unborn branch in the form "unborn HEAD + symref-target:". + The output of ls-refs is as follows: output = *ref flush-pkt - ref = PKT-LINE(obj-id SP refname *(SP ref-attribute) LF) + obj-id-or-unborn = (obj-id | "unborn") + ref = PKT-LINE(obj-id-or-unborn SP refname *(SP ref-attribute) LF) ref-attribute = (symref | peeled) symref = "symref-target:" symref-target peeled = "peeled:" obj-id diff --git a/ls-refs.c b/ls-refs.c index a1e0b473e4..32deb7be44 100644 --- a/ls-refs.c +++ b/ls-refs.c @@ -7,6 +7,39 @@ #include "pkt-line.h" #include "config.h" +static int config_read; +static int advertise_unborn; +static int allow_unborn; + +static void ensure_config_read(void) +{ + const char *str = NULL; + + if (config_read) + return; + + if (repo_config_get_string_tmp(the_repository, "lsrefs.unborn", &str)) { + /* + * If there is no such config, advertise and allow it by + * default. + */ + advertise_unborn = 1; + allow_unborn = 1; + } else { + if (!strcmp(str, "advertise")) { + advertise_unborn = 1; + allow_unborn = 1; + } else if (!strcmp(str, "allow")) { + allow_unborn = 1; + } else if (!strcmp(str, "ignore")) { + /* do nothing */ + } else { + die(_("invalid value '%s' for lsrefs.unborn"), str); + } + } + config_read = 1; +} + /* * Check if one of the prefixes is a prefix of the ref. * If no prefixes were provided, all refs match. @@ -32,6 +65,7 @@ struct ls_refs_data { unsigned peel; unsigned symrefs; struct strvec prefixes; + unsigned unborn : 1; }; static int send_ref(const char *refname, const struct object_id *oid, @@ -47,7 +81,10 @@ static int send_ref(const char *refname, const struct object_id *oid, if (!ref_match(&data->prefixes, refname_nons)) return 0; - strbuf_addf(&refline, "%s %s", oid_to_hex(oid), refname_nons); + if (oid) + strbuf_addf(&refline, "%s %s", oid_to_hex(oid), refname_nons); + else + strbuf_addf(&refline, "unborn %s", refname_nons); if (data->symrefs && flag & REF_ISSYMREF) { struct object_id unused; const char *symref_target = resolve_ref_unsafe(refname, 0, @@ -61,7 +98,7 @@ static int send_ref(const char *refname, const struct object_id *oid, strip_namespace(symref_target)); } - if (data->peel) { + if (data->peel && oid) { struct object_id peeled; if (!peel_ref(refname, &peeled)) strbuf_addf(&refline, " peeled:%s", oid_to_hex(&peeled)); @@ -74,6 +111,23 @@ static int send_ref(const char *refname, const struct object_id *oid, return 0; } +static void send_possibly_unborn_head(struct ls_refs_data *data) +{ + struct strbuf namespaced = STRBUF_INIT; + struct object_id oid; + int flag; + int oid_is_null; + + strbuf_addf(&namespaced, "%sHEAD", get_git_namespace()); + if (!resolve_ref_unsafe(namespaced.buf, 0, &oid, &flag)) + return; /* bad ref */ + oid_is_null = is_null_oid(&oid); + if (!oid_is_null || + (data->unborn && data->symrefs && (flag & REF_ISSYMREF))) + send_ref(namespaced.buf, oid_is_null ? NULL : &oid, flag, data); + strbuf_release(&namespaced); +} + static int ls_refs_config(const char *var, const char *value, void *data) { /* @@ -91,6 +145,7 @@ int ls_refs(struct repository *r, struct strvec *keys, memset(&data, 0, sizeof(data)); + ensure_config_read(); git_config(ls_refs_config, NULL); while (packet_reader_read(request) == PACKET_READ_NORMAL) { @@ -103,14 +158,27 @@ int ls_refs(struct repository *r, struct strvec *keys, data.symrefs = 1; else if (skip_prefix(arg, "ref-prefix ", &out)) strvec_push(&data.prefixes, out); + else if (!strcmp("unborn", arg)) + data.unborn = allow_unborn; } if (request->status != PACKET_READ_FLUSH) die(_("expected flush after ls-refs arguments")); - head_ref_namespaced(send_ref, &data); + send_possibly_unborn_head(&data); for_each_namespaced_ref(send_ref, &data); packet_flush(1); strvec_clear(&data.prefixes); return 0; } + +int ls_refs_advertise(struct repository *r, struct strbuf *value) +{ + if (value) { + ensure_config_read(); + if (advertise_unborn) + strbuf_addstr(value, "unborn"); + } + + return 1; +} diff --git a/ls-refs.h b/ls-refs.h index 7b33a7c6b8..a99e4be0bd 100644 --- a/ls-refs.h +++ b/ls-refs.h @@ -6,5 +6,6 @@ struct strvec; struct packet_reader; int ls_refs(struct repository *r, struct strvec *keys, struct packet_reader *request); +int ls_refs_advertise(struct repository *r, struct strbuf *value); #endif /* LS_REFS_H */ diff --git a/serve.c b/serve.c index eec2fe6f29..ac20c72763 100644 --- a/serve.c +++ b/serve.c @@ -73,7 +73,7 @@ struct protocol_capability { static struct protocol_capability capabilities[] = { { "agent", agent_advertise, NULL }, - { "ls-refs", always_advertise, ls_refs }, + { "ls-refs", ls_refs_advertise, ls_refs }, { "fetch", upload_pack_advertise, upload_pack_v2 }, { "server-option", always_advertise, NULL }, { "object-format", object_format_advertise, NULL }, diff --git a/t/t5701-git-serve.sh b/t/t5701-git-serve.sh index a1f5fdc9fd..df29504161 100755 --- a/t/t5701-git-serve.sh +++ b/t/t5701-git-serve.sh @@ -12,7 +12,7 @@ test_expect_success 'test capability advertisement' ' cat >expect <<-EOF && version 2 agent=git/$(git version | cut -d" " -f3) - ls-refs + ls-refs=unborn fetch=shallow server-option object-format=$(test_oid algo)