From: Jeff King <peff@peff.net>
To: git@vger.kernel.org
Cc: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Subject: [PATCH 4/5] make get_short_ref a public function
Date: Tue, 7 Apr 2009 03:14:20 -0400 [thread overview]
Message-ID: <20090407071420.GD2924@coredump.intra.peff.net> (raw)
In-Reply-To: <20090407070254.GA2870@coredump.intra.peff.net>
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 <peff@peff.net>
---
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
next prev parent reply other threads:[~2009-04-07 7:16 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-07 7:02 [RFC/PATCH 0/5] making upstream branch information accessible Jeff King
2009-04-07 7:05 ` [PATCH 1/5] for-each-ref: refactor get_short_ref function Jeff King
2009-04-07 7:06 ` [PATCH 2/5] for-each-ref: refactor refname handling Jeff King
2009-04-08 6:22 ` Junio C Hamano
2009-04-08 6:27 ` Jeff King
2009-04-07 7:09 ` [PATCH 3/5] for-each-ref: add "upstream" format field Jeff King
2009-04-07 7:14 ` Jeff King [this message]
2009-04-07 7:39 ` [PATCH 4/5] make get_short_ref a public function Bert Wesarg
2009-04-09 8:18 ` Jeff King
2009-04-09 9:05 ` Bert Wesarg
2009-04-11 17:14 ` [PATCH&RFC] get_short_ref(): add strict mode Bert Wesarg
2009-04-11 19:23 ` Junio C Hamano
2009-04-11 19:50 ` Bert Wesarg
2009-04-11 20:35 ` [PATCH] for-each-ref: refname:short utilize core.warnAmbiguousRefs Bert Wesarg
2009-04-13 8:15 ` [PATCH 4/5] make get_short_ref a public function Jeff King
2009-04-07 7:57 ` Michael J Gruber
2009-04-07 7:16 ` [PATCH 5/5] branch: show upstream branch when double verbose Jeff King
2009-04-07 8:02 ` Michael J Gruber
2009-04-09 8:23 ` Jeff King
2009-04-09 10:15 ` Santi Béjar
2009-04-13 8:34 ` Jeff King
2009-04-13 17:04 ` Wincent Colaiuta
2009-04-07 8:12 ` Paolo Ciarrocchi
2009-04-07 7:33 ` [PATCH] for-each-ref: remove multiple xstrdup() in get_short_ref() Bert Wesarg
2009-04-07 7:44 ` Jeff King
2009-04-07 7:54 ` Bert Wesarg
2009-04-07 21:41 ` Jeff King
2009-04-07 7:44 ` Bert Wesarg
-- strict thread matches above, loose matches on Subject: below --
2008-09-22 9:09 [PATCH 1/3] for-each-ref: utilize core.warnambiguousrefs for strict refname:short format Bert Wesarg
2008-09-22 9:09 ` [PATCH 2/3] for-each-ref: factor out get_short_ref() into refs.c:abbreviate_refname() Bert Wesarg
2008-09-22 9:09 ` [PATCH 3/3] git abbref-ref: new porcelain for abbreviate_ref() Bert Wesarg
2008-09-22 15:32 ` Shawn O. Pearce
2008-09-22 15:55 ` Junio C Hamano
2008-09-22 16:45 ` Bert Wesarg
2008-09-22 16:43 ` Bert Wesarg
2008-09-22 16:27 ` [PATCH 1/3] for-each-ref: utilize core.warnambiguousrefs for strict refname:short format Junio C Hamano
2008-09-22 18:00 ` Bert Wesarg
2008-10-17 23:58 ` Junio C Hamano
2008-10-18 1:50 ` Shawn O. Pearce
2008-10-18 6:55 ` Bert Wesarg
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