b[i] = letterBytes[idx]
			i--
		}
		cache >>= letterIdxBits
		remain--
	}

	return *(*string)(unsafe.Pointer(&b))
}

// generate random object name.
func getRandomObjectName() string {
	return randString(16)
}

// generate random bucket name.
func getRandomBucketName() string {
	return randString(60)
}