[PATCH v2 5/7] ref-filter: move ref_sorting flags to a bitfield

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Change the reverse/ignore_case/version sort flags in the ref_sorting
struct into a bitfield. Having three of them was already a bit
unwieldy, but it would be even more so if another flag needed a
function like ref_sorting_icase_all() introduced in
76f9e569adb (ref-filter: apply --ignore-case to all sorting keys,
2020-05-03).

A follow-up change will introduce such a flag, so let's move this over
to a bitfield. Instead of using the usual '#define' pattern I'm using
the "enum" pattern from builtin/rebase.c's b4c8eb024af (builtin
rebase: support --quiet, 2018-09-04).

Perhaps there's a more idiomatic way of doing the "for each in list
amend mask" pattern than this "mask/on" variable combo. This function
doesn't allow us to e.g. do any arbitrary changes to the bitfield for
multiple flags, but I think in this case that's fine. The common case
is that we're calling this with a list of one.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 builtin/branch.c       |  2 +-
 builtin/for-each-ref.c |  2 +-
 builtin/tag.c          |  2 +-
 ref-filter.c           | 24 +++++++++++++++---------
 ref-filter.h           | 12 +++++++-----
 5 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/builtin/branch.c b/builtin/branch.c
index 045866a51ae..2dd51a8653b 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -739,7 +739,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		 */
 		if (!sorting)
 			sorting = ref_default_sorting();
-		ref_sorting_icase_all(sorting, icase);
+		ref_sorting_set_sort_flags_all(sorting, REF_SORTING_ICASE, icase);
 		print_ref_list(&filter, sorting, &format);
 		print_columns(&output, colopts, NULL);
 		string_list_clear(&output, 0);
diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
index 9d1ecda2b8f..cb9c81a0460 100644
--- a/builtin/for-each-ref.c
+++ b/builtin/for-each-ref.c
@@ -70,7 +70,7 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 
 	if (!sorting)
 		sorting = ref_default_sorting();
-	ref_sorting_icase_all(sorting, icase);
+	ref_sorting_set_sort_flags_all(sorting, REF_SORTING_ICASE, icase);
 	filter.ignore_case = icase;
 
 	filter.name_patterns = argv;
diff --git a/builtin/tag.c b/builtin/tag.c
index ecf011776dc..24d35b746d1 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -485,7 +485,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 	}
 	if (!sorting)
 		sorting = ref_default_sorting();
-	ref_sorting_icase_all(sorting, icase);
+	ref_sorting_set_sort_flags_all(sorting, REF_SORTING_ICASE, icase);
 	filter.ignore_case = icase;
 	if (cmdmode == 'l') {
 		int ret;
diff --git a/ref-filter.c b/ref-filter.c
index 8882128cd3e..fe587afb80b 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -2362,11 +2362,12 @@ static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, stru
 	if (get_ref_atom_value(b, s->atom, &vb, &err))
 		die("%s", err.buf);
 	strbuf_release(&err);
-	if (s->version) {
+	if (s->sort_flags & REF_SORTING_VERSION) {
 		cmp = versioncmp(va->s, vb->s);
 	} else if (cmp_type == FIELD_STR) {
 		int (*cmp_fn)(const char *, const char *);
-		cmp_fn = s->ignore_case ? strcasecmp : strcmp;
+		cmp_fn = s->sort_flags & REF_SORTING_ICASE
+			? strcasecmp : strcmp;
 		cmp = cmp_fn(va->s, vb->s);
 	} else {
 		if (va->value < vb->value)
@@ -2377,7 +2378,7 @@ static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, stru
 			cmp = 1;
 	}
 
-	return (s->reverse) ? -cmp : cmp;
+	return (s->sort_flags & REF_SORTING_REVERSE) ? -cmp : cmp;
 }
 
 static int compare_refs(const void *a_, const void *b_, void *ref_sorting)
@@ -2392,15 +2393,20 @@ static int compare_refs(const void *a_, const void *b_, void *ref_sorting)
 			return cmp;
 	}
 	s = ref_sorting;
-	return s && s->ignore_case ?
+	return s && s->sort_flags & REF_SORTING_ICASE ?
 		strcasecmp(a->refname, b->refname) :
 		strcmp(a->refname, b->refname);
 }
 
-void ref_sorting_icase_all(struct ref_sorting *sorting, int flag)
+void ref_sorting_set_sort_flags_all(struct ref_sorting *sorting,
+				    unsigned int mask, int on)
 {
-	for (; sorting; sorting = sorting->next)
-		sorting->ignore_case = !!flag;
+	for (; sorting; sorting = sorting->next) {
+		if (on)
+			sorting->sort_flags |= mask;
+		else
+			sorting->sort_flags &= ~mask;
+	}
 }
 
 void ref_array_sort(struct ref_sorting *sorting, struct ref_array *array)
@@ -2537,12 +2543,12 @@ void parse_ref_sorting(struct ref_sorting **sorting_tail, const char *arg)
 	*sorting_tail = s;
 
 	if (*arg == '-') {
-		s->reverse = 1;
+		s->sort_flags |= REF_SORTING_REVERSE;
 		arg++;
 	}
 	if (skip_prefix(arg, "version:", &arg) ||
 	    skip_prefix(arg, "v:", &arg))
-		s->version = 1;
+		s->sort_flags |= REF_SORTING_VERSION;
 	s->atom = parse_sorting_atom(arg);
 }
 
diff --git a/ref-filter.h b/ref-filter.h
index feaef4a8fde..6296ae8bb27 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -28,9 +28,11 @@ struct atom_value;
 struct ref_sorting {
 	struct ref_sorting *next;
 	int atom; /* index into used_atom array (internal) */
-	unsigned reverse : 1,
-		ignore_case : 1,
-		version : 1;
+	enum {
+		REF_SORTING_REVERSE = 1<<0,
+		REF_SORTING_ICASE = 1<<1,
+		REF_SORTING_VERSION = 1<<2,
+	} sort_flags;
 };
 
 struct ref_array_item {
@@ -109,8 +111,8 @@ void ref_array_clear(struct ref_array *array);
 int verify_ref_format(struct ref_format *format);
 /*  Sort the given ref_array as per the ref_sorting provided */
 void ref_array_sort(struct ref_sorting *sort, struct ref_array *array);
-/*  Set the ignore_case flag for all elements of a sorting list */
-void ref_sorting_icase_all(struct ref_sorting *sorting, int flag);
+/*  Set REF_SORTING_* sort_flags for all elements of a sorting list */
+void ref_sorting_set_sort_flags_all(struct ref_sorting *sorting, unsigned int mask, int on);
 /*  Based on the given format and quote_style, fill the strbuf */
 int format_ref_array_item(struct ref_array_item *info,
 			  const struct ref_format *format,
-- 
2.29.2.222.g5d2a92d10f8