promisor-remote: output trace2 statistics for number of objects fetched

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

promisor-remote.c

@@ -12,7 +12,8 @@ void set_repository_format_partial_clone(char *partial_clone)
 	repository_format_partial_clone = xstrdup_or_null(partial_clone);
 }
 
-static int fetch_objects(const char *remote_name,
+static int fetch_objects(struct repository *repo,
+			 const char *remote_name,
 			 const struct object_id *oids,
 			 int oid_nr)
 {
@@ -30,6 +31,8 @@ static int fetch_objects(const char *remote_name,
 		die(_("promisor-remote: unable to fork off fetch subprocess"));
 	child_in = xfdopen(child.in, "w");
 
+	trace2_data_intmax("promisor", repo, "fetch_count", oid_nr);
+
 	for (i = 0; i < oid_nr; i++) {
 		if (fputs(oid_to_hex(&oids[i]), child_in) < 0)
 			die_errno(_("promisor-remote: could not write to fetch subprocess"));
@@ -238,7 +241,7 @@ int promisor_remote_get_direct(struct repository *repo,
 	promisor_remote_init();
 
 	for (r = promisors; r; r = r->next) {
-		if (fetch_objects(r->name, remaining_oids, remaining_nr) < 0) {
+		if (fetch_objects(repo, r->name, remaining_oids, remaining_nr) < 0) {
 			if (remaining_nr == 1)
 				continue;
 			remaining_nr = remove_fetched_oids(repo, &remaining_oids,