Use new ObjWaitExtend API

Fixes #44 properly

Ref https://github.com/varnishcache/varnish-cache/pull/4109

src/buddy_storage.c

@@ -320,6 +320,7 @@ sbu_iterator(struct worker *wrk, struct objcore *oc,
 	}
 	while (1) {
 		ol = len;
+#if VRT_MAJOR_VERSION < 19U || (VRT_MAJOR_VERSION == 19 && VRT_MINOR_VERSION < 1)
 		nl = ObjWaitExtend(wrk, oc, ol);
 		if (boc->state == BOS_FAILED) {
 			ret = -1;
@@ -330,6 +331,18 @@ sbu_iterator(struct worker *wrk, struct objcore *oc,
 				break;
 			continue;
 		}
+#else
+		nl = ObjWaitExtend(wrk, oc, ol, &state);
+		if (state == BOS_FAILED) {
+			ret = -1;
+			break;
+		}
+		if (nl == ol) {
+			assert (state == BOS_FINISHED);
+			break;
+		}
+		assert(nl > ol);
+#endif
 		Lck_Lock(&boc->mtx);
 		assert(VTAILQ_FIRST(&obj->list));
 		if (checkpoint == NULL) {
@@ -371,7 +384,6 @@ sbu_iterator(struct worker *wrk, struct objcore *oc,
 		st = VTAILQ_PREV(st, sbu_head, list);
 		if (st != NULL && st->len == 0)
 			st = NULL;
-		state = boc->state;
 		Lck_Unlock(&boc->mtx);
 		assert(l > 0 || state == BOS_FINISHED);
 		u = 0;

src/fellow_storage.c

@@ -715,6 +715,7 @@ struct fellow_stream {
 	ssize_t checkpoint;	// up to this segment
 };
 
+#if VRT_MAJOR_VERSION < 19U || (VRT_MAJOR_VERSION == 19 && VRT_MINOR_VERSION < 1)
 /*
  * NOTE on state shenanigans:
  *
@@ -746,6 +747,22 @@ fellow_stream_wait(struct fellow_stream *fs)
 
 	return (state2);
 }
+#else
+static enum boc_state_e
+fellow_stream_wait(struct fellow_stream *fs)
+{
+	uint64_t l;
+
+	CHECK_OBJ_NOTNULL(fs, FELLOW_STREAM_MAGIC);
+
+	l = (uint64_t)fs->available;
+	l = ObjWaitExtend(fs->wrk, fs->oc, l, &fs->state);
+
+	fs->available = (ssize_t)l;
+
+	return (fs->state);
+}
+#endif
 
 /* called on each (potentially busy) segment's data */
 static int v_matchproto_(objiterate_f)