if len(oi.Parts) == 1 {
		var rs *HTTPRangeSpec
		gr, err := getTransitionedObjectReader(ctx, bucket, object, rs, http.Header{}, oi, opts)
		if err != nil {
			return setRestoreHeaderFn(oi, toObjectErr(err, bucket, object))
		}
		defer gr.Close()
		hashReader, err := hash.NewReader(ctx, gr, gr.ObjInfo.Size, "", "", gr.ObjInfo.Size)
		if err != nil {