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[PATCH v3] for-each-ref: `:short` format for `refname`

From
Bert Wesarg <bert.wesarg@googlemail.com>
Date
Sep 3, 2008, 08:42 UTC
Message-ID
<1220431352-30605-1-git-send-email-bert.wesarg@googlemail.com>
In-Reply-To
<36ca99e90809030133r43fc5a3agad1aa38339a758a3@mail.gmail.com>
Try to shorten the refname to a non-ambiguous name.
Changes in v3:
 * don't compare sha1's, its ambiguous if the short name
   resovles to more than one ref
 * use xstrdup()
 * use indexes for the loops to clarify backward/forward
   direction
Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
Cc: git@vger.kernel.org
Cc: szeder@ira.uka.de
Cc: Shawn O. Pearce <spearce@spearce.org>
---
 Documentation/git-for-each-ref.txt |    1 +
 builtin-for-each-ref.c             |  138 ++++++++++++++++++++++++++++++++++--
 t/t6300-for-each-ref.sh            |   44 +++++++++++
 3 files changed, 176 insertions(+), 7 deletions(-)
diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
index eae6c0e..4016f59 100644
--- a/Documentation/git-for-each-ref.txt
+++ b/Documentation/git-for-each-ref.txt
@@ -74,6 +74,7 @@ For all objects, the following names can be used:
 
 refname::
 	The name of the ref (the part after $GIT_DIR/).
+	For a non-ambiguous short name of the ref append `:short`.
 
 objecttype::
 	The type of the object (`blob`, `tree`, `commit`, `tag`).
diff --git a/builtin-for-each-ref.c b/builtin-for-each-ref.c
index 21e92bb..abe0804 100644
--- a/builtin-for-each-ref.c
+++ b/builtin-for-each-ref.c
@@ -546,6 +546,110 @@ 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(struct refinfo *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 ref->refname;
+
+	/* buffer for scanf result, at most ref->refname must fit */
+	short_name = xstrdup(ref->refname);
+
+	/* 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->refname, 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 *p = ref_rev_parse_rules[j];
+			unsigned char short_objectname[20];
+
+			/* check for valid ref */
+			if (read_ref(mkpath(p, short_name_len, short_name),
+				     short_objectname))
+				continue;
+
+			/*
+			 * short_name resolves to a valid ref,
+			 * but its a differnet path than that of ref->refname,
+			 * therefore the short name is ambiguous
+			 */
+			break;
+		}
+
+		/*
+		 * short name is non-ambiguous if all previous rules
+		 * don't resolve to a valid ref
+		 */
+		if (j == i)
+			return short_name;
+	}
+
+	free(short_name);
+	return ref->refname;
+}
+
+
+/*
  * Parse the object referred by ref, and grab needed value.
  */
 static void populate_value(struct refinfo *ref)
@@ -570,13 +674,33 @@ static void populate_value(struct refinfo *ref)
 	for (i = 0; i < used_atom_cnt; i++) {
 		const char *name = used_atom[i];
 		struct atom_value *v = &ref->value[i];
-		if (!strcmp(name, "refname"))
-			v->s = ref->refname;
-		else if (!strcmp(name, "*refname")) {
-			int len = strlen(ref->refname);
-			char *s = xmalloc(len + 4);
-			sprintf(s, "%s^{}", ref->refname);
-			v->s = s;
+		int deref = 0;
+		if (*name == '*') {
+			deref = 1;
+			name++;
+		}
+		if (!prefixcmp(name, "refname")) {
+			const char *formatp = strchr(name, ':');
+			const char *refname = ref->refname;
+
+			/* look for "short" refname format */
+			if (formatp) {
+				formatp++;
+				if (!strcmp(formatp, "short"))
+					refname = get_short_ref(ref);
+				else
+					die("unknown refname format %s",
+					    formatp);
+			}
+
+			if (!deref)
+				v->s = refname;
+			else {
+				int len = strlen(refname);
+				char *s = xmalloc(len + 4);
+				sprintf(s, "%s^{}", refname);
+				v->s = s;
+			}
 		}
 	}
 
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index 8ced593..4f247dd 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -262,6 +262,50 @@ for i in "--perl --shell" "-s --python" "--python --tcl" "--tcl --perl"; do
 	"
 done
 
+cat >expected <<\EOF
+master
+testtag
+EOF
+
+test_expect_success 'Check short refname format' '
+	(git for-each-ref --format="%(refname:short)" refs/heads &&
+	git for-each-ref --format="%(refname:short)" refs/tags) >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'Check for invalid refname format' '
+	test_must_fail git for-each-ref --format="%(refname:INVALID)"
+'
+
+cat >expected <<\EOF
+heads/master
+master
+EOF
+
+test_expect_success 'Check ambiguous head and tag refs' '
+	git checkout -b newtag &&
+	echo "Using $datestamp" > one &&
+	git add one &&
+	git commit -m "Branch" &&
+	setdate_and_increment &&
+	git tag -m "Tagging at $datestamp" master &&
+	git for-each-ref --format "%(refname:short)" refs/heads/master refs/tags/master >actual &&
+	test_cmp expected actual
+'
+
+cat >expected <<\EOF
+heads/ambiguous
+ambiguous
+EOF
+
+test_expect_success 'Check ambiguous head and tag refs II' '
+	git checkout master &&
+	git tag ambiguous testtag^0 &&
+	git branch ambiguous testtag^0 &&
+	git for-each-ref --format "%(refname:short)" refs/heads/ambiguous refs/tags/ambiguous >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'an unusual tag with an incomplete line' '
 
 	git tag -m "bogo" bogo &&
-- 
1.6.0
Previous: Bert WesargNext: Shawn O. Pearce
Message 14 of 26 in “for-each-ref: `:short` format for `refname`”
  1. for-each-ref: `:short` format for `refname`Bert Wesarg, Aug 31, 2008
  2. SZEDER GáborSep 1, 2008
  3. Bert WesargSep 1, 2008
  4. Bert WesargSep 1, 2008
  5. Shawn O. PearceSep 1, 2008
  6. Bert WesargSep 1, 2008
  7. Junio C HamanoSep 1, 2008
  8. Bert WesargSep 1, 2008
  9. Bert WesargSep 2, 2008
  10. Shawn O. PearceSep 2, 2008
  11. for-each-ref: `:short` format for `refname`Bert Wesarg, Sep 2, 2008
  12. Junio C HamanoSep 2, 2008
  13. Bert WesargSep 3, 2008
  14. for-each-ref: `:short` format for `refname`Bert Wesarg, Sep 3, 2008
  15. Shawn O. PearceSep 3, 2008
  16. Bert WesargSep 3, 2008
  17. Bert WesargSep 3, 2008
  18. Junio C HamanoSep 3, 2008
  19. for-each-ref: `:short` format for `refname`Bert Wesarg, Sep 5, 2008
  20. Junio C HamanoSep 5, 2008
  21. Bert WesargSep 6, 2008
  22. Junio C HamanoSep 8, 2008
  23. Shawn O. PearceSep 8, 2008
  24. Bert WesargSep 9, 2008
  25. Junio C HamanoSep 9, 2008
  26. Bert WesargSep 9, 2008

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