From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: [PATCH 4/5] make get_short_ref a public function Date: Tue, 7 Apr 2009 03:14:20 -0400 Message-ID: <20090407071420.GD2924@coredump.intra.peff.net> References: <20090407070254.GA2870@coredump.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Paolo Ciarrocchi To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Tue Apr 07 09:16:15 2009 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1Lr5XX-0004q1-EA for gcvg-git-2@gmane.org; Tue, 07 Apr 2009 09:16:12 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751740AbZDGHOi (ORCPT ); Tue, 7 Apr 2009 03:14:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751452AbZDGHOh (ORCPT ); Tue, 7 Apr 2009 03:14:37 -0400 Received: from peff.net ([208.65.91.99]:42611 "EHLO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751323AbZDGHOg (ORCPT ); Tue, 7 Apr 2009 03:14:36 -0400 Received: (qmail 429 invoked by uid 107); 7 Apr 2009 07:14:22 -0000 Received: from coredump.intra.peff.net (HELO coredump.intra.peff.net) (10.0.0.2) by peff.net (qpsmtpd/0.40) with (AES128-SHA encrypted) SMTP; Tue, 07 Apr 2009 03:14:22 -0400 Received: by coredump.intra.peff.net (sSMTP sendmail emulation); Tue, 07 Apr 2009 03:14:20 -0400 Content-Disposition: inline In-Reply-To: <20090407070254.GA2870@coredump.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Often we want to shorten a full ref name to something "prettier" to show a user. For example, "refs/heads/master" is often shown simply as "master", or "refs/remotes/origin/master" is shown as "origin/master". Many places in the code use a very simple formula: skip common prefixes like refs/heads, refs/remotes, etc. This is codified in the prettify_ref function. for-each-ref has a more correct (but more expensive) approach: consider the ref lookup rules, and try shortening as much as possible while remaining unambiguous. This patch makes the latter strategy globally available as shorten_unambiguous_ref. Signed-off-by: Jeff King --- Actually, I am not quite sure that this function is "more correct". It looks at the rev-parsing rules as a hierarchy, so if you have "refs/remotes/foo" and "refs/heads/foo", then it will abbreviate the first to "remotes/foo" (as expected) and the latter to just "foo". This is technically correct, as "refs/heads/foo" will be selected by "foo", but it will warn about ambiguity. Should we actually try to avoid reporting refs which would be ambiguous? Should this simply replace prettify_ref (and other places which should be using prettify_ref but aren't)? It is definitely more expensive, as it has to resolve refs to look for ambiguities, but I don't know if we care in most code paths. builtin-for-each-ref.c | 105 +----------------------------------------------- refs.c | 99 +++++++++++++++++++++++++++++++++++++++++++++ refs.h | 1 + 3 files changed, 101 insertions(+), 104 deletions(-) diff --git a/builtin-for-each-ref.c b/builtin-for-each-ref.c index 277d1fb..8c82484 100644 --- a/builtin-for-each-ref.c +++ b/builtin-for-each-ref.c @@ -546,109 +546,6 @@ static void grab_values(struct atom_value *val, int deref, struct object *obj, v } /* - * generate a format suitable for scanf from a ref_rev_parse_rules - * rule, that is replace the "%.*s" spec with a "%s" spec - */ -static void gen_scanf_fmt(char *scanf_fmt, const char *rule) -{ - char *spec; - - spec = strstr(rule, "%.*s"); - if (!spec || strstr(spec + 4, "%.*s")) - die("invalid rule in ref_rev_parse_rules: %s", rule); - - /* copy all until spec */ - strncpy(scanf_fmt, rule, spec - rule); - scanf_fmt[spec - rule] = '\0'; - /* copy new spec */ - strcat(scanf_fmt, "%s"); - /* copy remaining rule */ - strcat(scanf_fmt, spec + 4); - - return; -} - -/* - * Shorten the refname to an non-ambiguous form - */ -static char *get_short_ref(const char *ref) -{ - int i; - static char **scanf_fmts; - static int nr_rules; - char *short_name; - - /* pre generate scanf formats from ref_rev_parse_rules[] */ - if (!nr_rules) { - size_t total_len = 0; - - /* the rule list is NULL terminated, count them first */ - for (; ref_rev_parse_rules[nr_rules]; nr_rules++) - /* no +1 because strlen("%s") < strlen("%.*s") */ - total_len += strlen(ref_rev_parse_rules[nr_rules]); - - scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len); - - total_len = 0; - for (i = 0; i < nr_rules; i++) { - scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] - + total_len; - gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]); - total_len += strlen(ref_rev_parse_rules[i]); - } - } - - /* bail out if there are no rules */ - if (!nr_rules) - return xstrdup(ref); - - /* buffer for scanf result, at most ref must fit */ - short_name = xstrdup(ref); - - /* skip first rule, it will always match */ - for (i = nr_rules - 1; i > 0 ; --i) { - int j; - int short_name_len; - - if (1 != sscanf(ref, scanf_fmts[i], short_name)) - continue; - - short_name_len = strlen(short_name); - - /* - * check if the short name resolves to a valid ref, - * but use only rules prior to the matched one - */ - for (j = 0; j < i; j++) { - const char *rule = ref_rev_parse_rules[j]; - unsigned char short_objectname[20]; - char refname[PATH_MAX]; - - /* - * the short name is ambiguous, if it resolves - * (with this previous rule) to a valid ref - * read_ref() returns 0 on success - */ - mksnpath(refname, sizeof(refname), - rule, short_name_len, short_name); - if (!read_ref(refname, short_objectname)) - break; - } - - /* - * short name is non-ambiguous if all previous rules - * haven't resolved to a valid ref - */ - if (j == i) - return short_name; - } - - free(short_name); - return xstrdup(ref); -} - - -/* * Parse the object referred by ref, and grab needed value. */ static void populate_value(struct refinfo *ref) @@ -704,7 +601,7 @@ static void populate_value(struct refinfo *ref) if (formatp) { formatp++; if (!strcmp(formatp, "short")) - refname = get_short_ref(refname); + refname = shorten_unambiguous_ref(refname); else die("unknown %.*s format %s", formatp - name, name, formatp); diff --git a/refs.c b/refs.c index 59c373f..1e5e7b4 100644 --- a/refs.c +++ b/refs.c @@ -1652,3 +1652,102 @@ struct ref *find_ref_by_name(const struct ref *list, const char *name) return (struct ref *)list; return NULL; } + +/* + * generate a format suitable for scanf from a ref_rev_parse_rules + * rule, that is replace the "%.*s" spec with a "%s" spec + */ +static void gen_scanf_fmt(char *scanf_fmt, const char *rule) +{ + char *spec; + + spec = strstr(rule, "%.*s"); + if (!spec || strstr(spec + 4, "%.*s")) + die("invalid rule in ref_rev_parse_rules: %s", rule); + + /* copy all until spec */ + strncpy(scanf_fmt, rule, spec - rule); + scanf_fmt[spec - rule] = '\0'; + /* copy new spec */ + strcat(scanf_fmt, "%s"); + /* copy remaining rule */ + strcat(scanf_fmt, spec + 4); + + return; +} + +char *shorten_unambiguous_ref(const char *ref) +{ + int i; + static char **scanf_fmts; + static int nr_rules; + char *short_name; + + /* pre generate scanf formats from ref_rev_parse_rules[] */ + if (!nr_rules) { + size_t total_len = 0; + + /* the rule list is NULL terminated, count them first */ + for (; ref_rev_parse_rules[nr_rules]; nr_rules++) + /* no +1 because strlen("%s") < strlen("%.*s") */ + total_len += strlen(ref_rev_parse_rules[nr_rules]); + + scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len); + + total_len = 0; + for (i = 0; i < nr_rules; i++) { + scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + + total_len; + gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]); + total_len += strlen(ref_rev_parse_rules[i]); + } + } + + /* bail out if there are no rules */ + if (!nr_rules) + return xstrdup(ref); + + /* buffer for scanf result, at most ref must fit */ + short_name = xstrdup(ref); + + /* skip first rule, it will always match */ + for (i = nr_rules - 1; i > 0 ; --i) { + int j; + int short_name_len; + + if (1 != sscanf(ref, scanf_fmts[i], short_name)) + continue; + + short_name_len = strlen(short_name); + + /* + * check if the short name resolves to a valid ref, + * but use only rules prior to the matched one + */ + for (j = 0; j < i; j++) { + const char *rule = ref_rev_parse_rules[j]; + unsigned char short_objectname[20]; + char refname[PATH_MAX]; + + /* + * the short name is ambiguous, if it resolves + * (with this previous rule) to a valid ref + * read_ref() returns 0 on success + */ + mksnpath(refname, sizeof(refname), + rule, short_name_len, short_name); + if (!read_ref(refname, short_objectname)) + break; + } + + /* + * short name is non-ambiguous if all previous rules + * haven't resolved to a valid ref + */ + if (j == i) + return short_name; + } + + free(short_name); + return xstrdup(ref); +} diff --git a/refs.h b/refs.h index 68c2d16..2d0f961 100644 --- a/refs.h +++ b/refs.h @@ -80,6 +80,7 @@ extern int for_each_reflog(each_ref_fn, void *); extern int check_ref_format(const char *target); extern const char *prettify_ref(const struct ref *ref); +extern char *shorten_unambiguous_ref(const char *ref); /** rename ref, return 0 on success **/ extern int rename_ref(const char *oldref, const char *newref, const char *logmsg); -- 1.6.2.2.450.gd6aa9.dirty