From patchwork Fri Feb 5 04:58:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Tan X-Patchwork-Id: 12069287 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 BC186C433DB for ; Fri, 5 Feb 2021 04:59:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77F6464E22 for ; Fri, 5 Feb 2021 04:59:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231200AbhBEE72 (ORCPT ); Thu, 4 Feb 2021 23:59:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231168AbhBEE7U (ORCPT ); Thu, 4 Feb 2021 23:59:20 -0500 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4A9AC06178A for ; Thu, 4 Feb 2021 20:58:39 -0800 (PST) Received: by mail-pf1-x44a.google.com with SMTP id t16so4048492pfh.22 for ; Thu, 04 Feb 2021 20:58:39 -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=44iXLyYlG6pFAz+0dCRTOvE38Y784hK0/VnCluqyfYw=; b=blqxI74WqxFrt37grLQHfvn+wgBN/0i6GfET8dOYx0tgoq+1xukfEuYpcjT35RN9x8 62ERb92ZFQVBxHPeP2feVbLxlTQKy6Fg6LERD/xfuzvqK3Tg5fV98voziLdvDSsmecih xBjjEZidA9AiwvSQOi+d8/2g9R7CcODp30Mpp18BLO0CJPzD2MznypkYYl0mLYtTXLQj L0/CVw0lkYgin1/1oHKa82nWFav7ZLCQyqq6EJK73lmrC1Dj3ceCytZnBj1molWVa5j8 na6ajPaImRsjOfxHzT39W3Hwe3oFpknQLc2UQ6k5q7J/lEO1i1UOm6qqtJlIR7yaX4ha H3jQ== 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=44iXLyYlG6pFAz+0dCRTOvE38Y784hK0/VnCluqyfYw=; b=cxpqpusYkVBUAvNOSUJEABAgGxfUhpYh+qBvj6s/FDu/JHV69qR8uSlDADuxyWxmxG i7F3fJ23KA9Q6wPyuQajT2IV7EQyineQUIQO0gXJ+2Bm2go7HM6UFp3eTxzJFT51u2zG 4bd/TQLTjVHqN2pC1oOriZRdQ40EnQX1W2C3i2GuhPiCDRnua49qHb99rUHBFgDkiq+E /+lV9+mBRTRyLN1pNgg6hjV/v3r9elQWH8n6yIhvPGLdyesUhtrS7+/7DoLvSFwF3hm8 zuZQ+I7RaI8Z1j40PRLBLUE0TAsrs/ezcS2/9bf7nULatteXbrXp17BAjnuowSnwZAv0 iamw== X-Gm-Message-State: AOAM532pyT5IZCoY8DPMuGqUNXEa5fq/kT/bWR6U3H9MCU7jETxJLpLY IBlMYR5yFrfQ4Rt04K1A6H2uy9xrc0B5UQWtfQAmFdDoqkjOEAK12Pq/4SmND8KiNthfwbg1+7d xsmKNFyaLgZEh4Vth9IF9fBxi9bul3wBnvU4G9eFNb69gpq/Qgne9SgRk6WBAwzOtL/3oJ4K/pD RF X-Google-Smtp-Source: ABdhPJzQGEOxSH5O75J6DjepAyfDMo8JmMjJjClfta6RFQYtxrQUO2krpEd+fEXWMB7Hj63vcceU5KkHtGjCw5zCEctq 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:a17:902:9690:b029:e1:5a03:87b5 with SMTP id n16-20020a1709029690b02900e15a0387b5mr2377120plp.39.1612501119306; Thu, 04 Feb 2021 20:58:39 -0800 (PST) Date: Thu, 4 Feb 2021 20:58:31 -0800 In-Reply-To: Message-Id: <2d3507536924346637bb138af5a3562ce8f2abc2.1612493309.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 v7 1/3] ls-refs: report unborn targets of symrefs From: Jonathan Tan To: git@vger.kernel.org Cc: Jonathan Tan , gitster@pobox.com 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..e003856c08 --- /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 automatically (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..e08fd43e7a 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) +{ + char *str = NULL; + + if (config_read) + return; + + if (repo_config_get_string(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)