Merge branch 'kn/bundle-dedup-optim'

Optimize the code to dedup references recorded in a bundle file.

* kn/bundle-dedup-optim:
bundle: fix non-linear performance scaling with refs
t6020: test for duplicate refnames in bundle creation

bundle.c

···
 {
 	int i;
 	int ref_count = 0;
+	struct strset objects = STRSET_INIT;
 
 	for (i = 0; i < revs->pending.nr; i++) {
 		struct object_array_entry *e = revs->pending.objects + i;
···
 		if (refs_read_ref_full(get_main_ref_store(the_repository), e->name, RESOLVE_REF_READING, &oid, &flag))
 			flag = 0;
 		display_ref = (flag & REF_ISSYMREF) ? e->name : ref;
+
+		if (strset_contains(&objects, display_ref))
+			goto skip_write_ref;
 
 		if (e->item->type == OBJ_TAG &&
 				!is_tag_in_date_range(e->item, revs)) {
···
 		}
 
 		ref_count++;
+		strset_add(&objects, display_ref);
 		write_or_die(bundle_fd, oid_to_hex(&e->item->oid), the_hash_algo->hexsz);
 		write_or_die(bundle_fd, " ", 1);
 		write_or_die(bundle_fd, display_ref, strlen(display_ref));
···
  skip_write_ref:
 		free(ref);
 	}
+
+	strset_clear(&objects);
 
 	/* end header */
 	write_or_die(bundle_fd, "\n", 1);
···
 	 */
 	revs.blob_objects = revs.tree_objects = 0;
 	traverse_commit_list(&revs, write_bundle_prerequisites, NULL, &bpi);
-	object_array_remove_duplicates(&revs_copy.pending);
 
 	/* write bundle refs */
 	ref_count = write_bundle_refs(bundle_fd, &revs_copy);

object.c

···
 	array->nr = array->alloc = 0;
 }
 
-/*
- * Return true if array already contains an entry.
- */
-static int contains_object(struct object_array *array,
-			   const struct object *item, const char *name)
-{
-	unsigned nr = array->nr, i;
-	struct object_array_entry *object = array->objects;
-
-	for (i = 0; i < nr; i++, object++)
-		if (item == object->item && !strcmp(object->name, name))
-			return 1;
-	return 0;
-}
-
-void object_array_remove_duplicates(struct object_array *array)
-{
-	unsigned nr = array->nr, src;
-	struct object_array_entry *objects = array->objects;
-
-	array->nr = 0;
-	for (src = 0; src < nr; src++) {
-		if (!contains_object(array, objects[src].item,
-				     objects[src].name)) {
-			if (src != array->nr)
-				objects[array->nr] = objects[src];
-			array->nr++;
-		} else {
-			object_array_release_entry(&objects[src]);
-		}
-	}
-}
-
 void clear_object_flags(struct repository *repo, unsigned flags)
 {
 	int i;
 
-	for (i=0; i < repo->parsed_objects->obj_hash_size; i++) {
+	for (i = 0; i < repo->parsed_objects->obj_hash_size; i++) {
 		struct object *obj = repo->parsed_objects->obj_hash[i];
 		if (obj)
 			obj->flags &= ~flags;

object.h

···
 			 object_array_each_func_t want, void *cb_data);
 
 /*
- * Remove from array all but the first entry with a given name.
- * Warning: this function uses an O(N^2) algorithm.
- */
-void object_array_remove_duplicates(struct object_array *array);
-
-/*
  * Remove any objects from the array, freeing all used memory; afterwards
  * the array is ready to store more objects with add_object_array().
  */

t/t6020-bundle-misc.sh

···
 	grep "%" err
 '
 
+test_expect_success 'create bundle with duplicate refnames' '
+	git bundle create out.bdl "main" "main" &&
+
+	git bundle list-heads out.bdl |
+		make_user_friendly_and_stable_output >actual &&
+	cat >expect <<-\EOF &&
+	<COMMIT-P> refs/heads/main
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'create bundle with duplicate refnames and --all' '
+	git bundle create out.bdl --all "main" "main" &&
+
+	git bundle list-heads out.bdl |
+		make_user_friendly_and_stable_output >actual &&
+	cat >expect <<-\EOF &&
+	<COMMIT-P> refs/heads/main
+	<COMMIT-N> refs/heads/release
+	<COMMIT-D> refs/heads/topic/1
+	<COMMIT-H> refs/heads/topic/2
+	<COMMIT-D> refs/pull/1/head
+	<COMMIT-G> refs/pull/2/head
+	<TAG-1> refs/tags/v1
+	<TAG-2> refs/tags/v2
+	<TAG-3> refs/tags/v3
+	<COMMIT-P> HEAD
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'create bundle with duplicate exlusion refnames' '
+	git bundle create out.bdl "main" "main^!" &&
+
+	git bundle list-heads out.bdl |
+		make_user_friendly_and_stable_output >actual &&
+	cat >expect <<-\EOF &&
+	<COMMIT-P> refs/heads/main
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'create bundle with duplicate refname short-form' '
+	git bundle create out.bdl "main" "main" "refs/heads/main" "refs/heads/main" &&
+
+	git bundle list-heads out.bdl |
+		make_user_friendly_and_stable_output >actual &&
+	cat >expect <<-\EOF &&
+	<COMMIT-P> refs/heads/main
+	EOF
+	test_cmp expect actual
+'
+
 test_expect_success 'read bundle over stdin' '
 	git bundle create some.bundle HEAD &&