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=-4.4 required=3.0 tests=AWL,BAYES_00, 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 B0D2A1F66E for ; Sat, 15 Aug 2020 00:25:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727961AbgHOAZc (ORCPT ); Fri, 14 Aug 2020 20:25:32 -0400 Received: from mga01.intel.com ([192.55.52.88]:29193 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726830AbgHOAZb (ORCPT ); Fri, 14 Aug 2020 20:25:31 -0400 IronPort-SDR: RTYcluoOqY1z9m4pNuhl6cuJpwAC74ugELPzTxSHb4HV43PwsTF5mC4hrMWM9MSp+QDMmhJqLh 05hYI9NdaqRA== X-IronPort-AV: E=McAfee;i="6000,8403,9713"; a="172554199" X-IronPort-AV: E=Sophos;i="5.76,314,1592895600"; d="scan'208";a="172554199" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2020 17:25:31 -0700 IronPort-SDR: MobSftoOqAbSrUQACyjojQI0jlsLAKdd4OLa9OCWTUWaV5WGXxrua2NMZX6p3xq9lyVebpCsYU 1eyaCTRLERMA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,314,1592895600"; d="scan'208";a="325861566" Received: from jekeller-desk.amr.corp.intel.com ([10.166.241.33]) by orsmga008.jf.intel.com with ESMTP; 14 Aug 2020 17:25:30 -0700 From: Jacob Keller To: git@vger.kernel.org, Jeff King Cc: Jacob Keller Subject: [RFC 3/3] refspec: add support for negative refspecs Date: Fri, 14 Aug 2020 17:25:09 -0700 Message-Id: <20200815002509.2467645-3-jacob.e.keller@intel.com> X-Mailer: git-send-email 2.28.0.163.g6104cc2f0b60 In-Reply-To: <20200815002509.2467645-1-jacob.e.keller@intel.com> References: <20200815002509.2467645-1-jacob.e.keller@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Jacob Keller Both fetch and push support pattern refspecs which allow fetching or pushing references that match a specific pattern. Because these patterns are globs, they have somewhat limited ability to express more complex situations. For example, suppose you wish to fetch all branches from a remote except for a specific one. To allow this, you must setup a set of refspecs which match only the branches you want. Because refspecs are either explicit name matches, or simple globs, many patterns cannot be expressed. Add support for a new type of refspec, referred to as "negative" refspecs. These are prefixed with a '^' and mean "exclude any ref matching this refspec". They can only have one "side" which always refers to the source. During a fetch, this refers to the name of the ref on the remote. During a push, this refers to the name of the ref on the local side. With negative refspecs, users can express more complex patterns. For example: git fetch origin refs/heads/*:refs/remotes/origin/* ^refs/heads/dontwant will fetch all branches on origin into remotes/origin, but will exclude fetching the branch named dontwant. Refspecs today are commutative, meaning that order doesn't expressly matter. Rather than forcing an implied order, negative refspecs will always be applied last. That is, in order to match, a ref must match at least one positive refspec, and match none of the negative refspecs. This is similar to how negative pathspecs work. Signed-off-by: Jacob Keller --- builtin/fetch.c | 3 +++ refspec.c | 30 ++++++++++++++++++++++++++++++ refspec.h | 14 ++++++++------ remote.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- remote.h | 9 ++++++++- 5 files changed, 97 insertions(+), 8 deletions(-) diff --git a/builtin/fetch.c b/builtin/fetch.c index c49f0e975203..930214626b54 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -530,6 +530,9 @@ static struct ref *get_ref_map(struct remote *remote, tail = &rm->next; } + /* apply any negative refspecs now to prune the list of refs */ + ref_map = apply_negative_refspecs(ref_map, rs); + ref_map = ref_remove_duplicates(ref_map); refname_hash_init(&existing_refs); diff --git a/refspec.c b/refspec.c index f10ef284cef9..feed20aca961 100644 --- a/refspec.c +++ b/refspec.c @@ -8,6 +8,7 @@ static struct refspec_item s_tag_refspec = { 1, 0, 0, + 0, "refs/tags/*", "refs/tags/*" }; @@ -32,10 +33,17 @@ static int parse_refspec(struct refspec_item *item, const char *refspec, int fet if (*lhs == '+') { item->force = 1; lhs++; + } else if (*lhs == '^') { + item->negative = 1; + lhs++; } rhs = strrchr(lhs, ':'); + /* negative refspecs only have one side */ + if (item->negative && rhs) + return 0; + /* * Before going on, special case ":" (or "+:") as a refspec * for pushing matching refs. @@ -66,6 +74,28 @@ static int parse_refspec(struct refspec_item *item, const char *refspec, int fet item->src = xstrndup(lhs, llen); flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0); + if (item->negative) { + struct object_id unused; + + /* + * Negative refspecs only have a LHS, which indicates a ref + * (or pattern of refs) to exclude from other matches. This + * can either be a simple ref, a glob pattern, or even an + * exact sha1 match. + */ + if (!*item->src) + return 0; /* negative refspecs must not be empty */ + else if (llen == the_hash_algo->hexsz && !get_oid_hex(item->src, &unused)) + item->exact_sha1 = 1; /* ok */ + else if (!check_refname_format(item->src, flags)) + ; /* valid looking ref is ok */ + else + return 0; + + /* other rules for negative refspecs don't apply */ + return 1; + } + if (fetch) { struct object_id unused; diff --git a/refspec.h b/refspec.h index 8d654e3a3ac4..e5bf6d25d0f7 100644 --- a/refspec.h +++ b/refspec.h @@ -5,12 +5,13 @@ extern const struct refspec_item *tag_refspec; /** - * A struct refspec_item holds the parsed interpretation of a refspec. If it will - * force updates (starts with a '+'), force is true. If it is a pattern - * (sides end with '*') pattern is true. src and dest are the two sides - * (including '*' characters if present); if there is only one side, it is src, - * and dst is NULL; if sides exist but are empty (i.e., the refspec either - * starts or ends with ':'), the corresponding side is "". + * A struct refspec_item holds the parsed interpretation of a refspec. If it + * will force updates (starts with a '+'), force is true. If it is a pattern + * (sides end with '*') pattern is true. If it is a negative refspec, (starts + * with '^'), negative is true. src and dest are the two sides (including '*' + * characters if present); if there is only one side, it is src, and dst is + * NULL; if sides exist but are empty (i.e., the refspec either starts or ends + * with ':'), the corresponding side is "". * * remote_find_tracking(), given a remote and a struct refspec_item with either src * or dst filled out, will fill out the other such that the result is in the @@ -22,6 +23,7 @@ struct refspec_item { unsigned pattern : 1; unsigned matching : 1; unsigned exact_sha1 : 1; + unsigned negative : 1; char *src; char *dst; diff --git a/remote.c b/remote.c index c5ed74f91c63..6a41d1028221 100644 --- a/remote.c +++ b/remote.c @@ -1058,7 +1058,7 @@ static int match_explicit(struct ref *src, struct ref *dst, const char *dst_value = rs->dst; char *dst_guess; - if (rs->pattern || rs->matching) + if (rs->pattern || rs->matching || rs->negative) return 0; matched_src = matched_dst = NULL; @@ -1134,6 +1134,10 @@ static char *get_ref_match(const struct refspec *rs, const struct ref *ref, int matching_refs = -1; for (i = 0; i < rs->nr; i++) { const struct refspec_item *item = &rs->items[i]; + + if (item->negative) + continue; + if (item->matching && (matching_refs == -1 || item->force)) { matching_refs = i; @@ -1441,6 +1445,8 @@ int match_push_refs(struct ref *src, struct ref **dst, string_list_clear(&src_ref_index, 0); } + *dst = apply_negative_refspecs(*dst, rs); + if (errs) return -1; return 0; @@ -1810,6 +1816,9 @@ int get_fetch_map(const struct ref *remote_refs, { struct ref *ref_map, **rmp; + if (refspec->negative) + return 0; + if (refspec->pattern) { ref_map = get_expanded_map(remote_refs, refspec); } else { @@ -1853,6 +1862,44 @@ int get_fetch_map(const struct ref *remote_refs, return 0; } +static int refspec_match(const struct refspec_item *refspec, + const char *name) +{ + if (refspec->pattern) + return match_name_with_pattern(refspec->src, name, NULL, NULL); + + return !strcmp(refspec->src, name); +} + +static int omit_name_by_refspec(const char *name, struct refspec *rs) +{ + int i; + + for (i = 0; i < rs->nr; i++) { + if (rs->items[i].negative && refspec_match(&rs->items[i], name)) + return 1; + } + return 0; +} + +struct ref *apply_negative_refspecs(struct ref *ref_map, struct refspec *rs) +{ + struct ref **tail; + + for (tail = &ref_map; *tail; ) { + struct ref *ref = *tail; + + if (omit_name_by_refspec(ref->name, rs)) { + *tail = ref->next; + free(ref->peer_ref); + free(ref); + } else + tail = &ref->next; + } + + return ref_map; +} + int resolve_remote_symref(struct ref *ref, struct ref *list) { if (!ref->symref) diff --git a/remote.h b/remote.h index 5e3ea5a26deb..104e75e0f74d 100644 --- a/remote.h +++ b/remote.h @@ -193,6 +193,12 @@ int resolve_remote_symref(struct ref *ref, struct ref *list); */ struct ref *ref_remove_duplicates(struct ref *ref_map); +/* + * Remove all entries in the input list which match any negative refspec in + * the refspec list. + */ +struct ref *apply_negative_refspecs(struct ref *ref_map, struct refspec *rs); + int query_refspecs(struct refspec *rs, struct refspec_item *query); char *apply_refspecs(struct refspec *rs, const char *name); @@ -205,7 +211,8 @@ void set_ref_status_for_push(struct ref *remote_refs, int send_mirror, /* * Given a list of the remote refs and the specification of things to * fetch, makes a (separate) list of the refs to fetch and the local - * refs to store into. + * refs to store into. Note that negative refspecs are ignored here, and + * should be handled separately. * * *tail is the pointer to the tail pointer of the list of results * beforehand, and will be set to the tail pointer of the list of -- 2.28.0.163.g6104cc2f0b60