for-each-ref: introduce new structures for better organisation

Introduce 'ref_filter_cbdata' which will hold 'ref_filter'
(conditions to filter the refs on) and 'ref_array' (the array
of ref_array_items). Modify the code to use these new structures.

This is a preparatory patch to eventually move code from 'for-each-ref'
to 'ref-filter' and make it publicly available.
Mentored-by: NChristian Couder <christian.couder@gmail.com>
Mentored-by: NMatthieu Moy <matthieu.moy@grenoble-inp.fr>
Signed-off-by: NKarthik Nayak <karthik.188@gmail.com>
Reviewed-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

builtin/for-each-ref.c

@@ -39,6 +39,20 @@ struct ref_array_item {
 	char *refname;
 };
 
+struct ref_array {
+	int nr, alloc;
+	struct ref_array_item **items;
+};
+
+struct ref_filter {
+	const char **name_patterns;
+};
+
+struct ref_filter_cbdata {
+	struct ref_array array;
+	struct ref_filter filter;
+};
+
 static struct {
 	const char *name;
 	cmp_type cmp_type;
@@ -844,12 +858,6 @@ static void get_value(struct ref_array_item *ref, int atom, struct atom_value **
 	*v = &ref->value[atom];
 }
 
-struct grab_ref_cbdata {
-	struct ref_array_item **grab_array;
-	const char **grab_pattern;
-	int grab_cnt;
-};
-
 /*
  * Return 1 if the refname matches one of the patterns, otherwise 0.
  * A pattern can be path prefix (e.g. a refname "refs/heads/master"
@@ -895,7 +903,8 @@ static struct ref_array_item *new_ref_array_item(const char *refname,
 static int grab_single_ref(const char *refname, const struct object_id *oid,
 			   int flag, void *cb_data)
 {
-	struct grab_ref_cbdata *cb = cb_data;
+	struct ref_filter_cbdata *ref_cbdata = cb_data;
+	struct ref_filter *filter = &ref_cbdata->filter;
 	struct ref_array_item *ref;
 
 	if (flag & REF_BAD_NAME) {
@@ -903,7 +912,7 @@ static int grab_single_ref(const char *refname, const struct object_id *oid,
 		  return 0;
 	}
 
-	if (*cb->grab_pattern && !match_name_as_path(cb->grab_pattern, refname))
+	if (*filter->name_patterns && !match_name_as_path(filter->name_patterns, refname))
 		return 0;
 
 	/*
@@ -913,8 +922,8 @@ static int grab_single_ref(const char *refname, const struct object_id *oid,
 	 */
 	ref = new_ref_array_item(refname, oid->hash, flag);
 
-	REALLOC_ARRAY(cb->grab_array, cb->grab_cnt + 1);
-	cb->grab_array[cb->grab_cnt++] = ref;
+	REALLOC_ARRAY(ref_cbdata->array.items, ref_cbdata->array.nr + 1);
+	ref_cbdata->array.items[ref_cbdata->array.nr++] = ref;
 	return 0;
 }
 
@@ -957,10 +966,10 @@ static int compare_refs(const void *a_, const void *b_)
 	return 0;
 }
 
-static void sort_refs(struct ref_sort *sort, struct ref_array_item **refs, int num_refs)
+static void sort_refs(struct ref_sort *sort, struct ref_array *array)
 {
 	ref_sort = sort;
-	qsort(refs, num_refs, sizeof(struct ref_array_item *), compare_refs);
+	qsort(array->items, array->nr, sizeof(struct ref_array_item *), compare_refs);
 }
 
 static void print_value(struct atom_value *v, int quote_style)
@@ -1096,12 +1105,11 @@ static char const * const for_each_ref_usage[] = {
 
 int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 {
-	int i, num_refs;
+	int i;
 	const char *format = "%(objectname) %(objecttype)\t%(refname)";
 	struct ref_sort *sort = NULL, **sort_tail = &sort;
 	int maxcount = 0, quote_style = 0;
-	struct ref_array_item **refs;
-	struct grab_ref_cbdata cbdata;
+	struct ref_filter_cbdata ref_cbdata;
 
 	struct option opts[] = {
 		OPT_BIT('s', "shell", &quote_style,
@@ -1139,17 +1147,15 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 	/* for warn_ambiguous_refs */
 	git_config(git_default_config, NULL);
 
-	memset(&cbdata, 0, sizeof(cbdata));
-	cbdata.grab_pattern = argv;
-	for_each_rawref(grab_single_ref, &cbdata);
-	refs = cbdata.grab_array;
-	num_refs = cbdata.grab_cnt;
+	memset(&ref_cbdata, 0, sizeof(ref_cbdata));
+	ref_cbdata.filter.name_patterns = argv;
+	for_each_rawref(grab_single_ref, &ref_cbdata);
 
-	sort_refs(sort, refs, num_refs);
+	sort_refs(sort, &ref_cbdata.array);
 
-	if (!maxcount || num_refs < maxcount)
-		maxcount = num_refs;
+	if (!maxcount || ref_cbdata.array.nr < maxcount)
+		maxcount = ref_cbdata.array.nr;
 	for (i = 0; i < maxcount; i++)
-		show_ref(refs[i], format, quote_style);
+		show_ref(ref_cbdata.array.items[i], format, quote_style);
 	return 0;
 }