ref-filter: factor ref_array pushing into its own function

In preparation for callers constructing their own ref_array
structs, let's move our own internal push operation into its
own function.

While we're at it, we can replace REALLOC_ARRAY() with
ALLOC_GROW(), which should give the growth operation
amortized linear complexity (as opposed to growing by one,
which is potentially quadratic, though in-place realloc
growth often makes this faster in practice).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/ref-filter.c b/ref-filter.c
index c1c3cc9..6e9328b 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -1840,6 +1840,18 @@ static struct ref_array_item *new_ref_array_item(const char *refname,
 	return ref;
 }
 
+struct ref_array_item *ref_array_push(struct ref_array *array,
+				      const char *refname,
+				      const struct object_id *oid)
+{
+	struct ref_array_item *ref = new_ref_array_item(refname, oid);
+
+	ALLOC_GROW(array->items, array->nr + 1, array->alloc);
+	array->items[array->nr++] = ref;
+
+	return ref;
+}
+
 static int ref_kind_from_refname(const char *refname)
 {
 	unsigned int i;
@@ -1930,13 +1942,11 @@ static int ref_filter_handler(const char *refname, const struct object_id *oid,
 	 * to do its job and the resulting list may yet to be pruned
 	 * by maxcount logic.
 	 */
-	ref = new_ref_array_item(refname, oid);
+	ref = ref_array_push(ref_cbdata->array, refname, oid);
 	ref->commit = commit;
 	ref->flag = flag;
 	ref->kind = kind;
 
-	REALLOC_ARRAY(ref_cbdata->array->items, ref_cbdata->array->nr + 1);
-	ref_cbdata->array->items[ref_cbdata->array->nr++] = ref;
 	return 0;
 }