Function parseNFSTransportStats

mountstats.go:596–710

parseNFSTransportStats parses a NFSTransportStats line using an input set of integer fields matched to a specific stats version.

(ss []string, statVersion string)

// parseNFSTransportStats parses a NFSTransportStats line using an input set of
// integer fields matched to a specific stats version.
func parseNFSTransportStats(ss []string, statVersion string) (*NFSTransportStats, error) {
	// Extract the protocol field. It is the only string value in the line
	protocol := ss[0]
	ss = ss[1:]

	switch statVersion {
	case statVersion10:
		var expectedLength int
		switch protocol {
		case "tcp":
			expectedLength = fieldTransport10TCPLen
		case "udp":
			expectedLength = fieldTransport10UDPLen
		default:
			return nil, fmt.Errorf("%w: Invalid NFS protocol \"%s\" in stats 1.0 statement: %v", ErrFileParse, protocol, ss)
		}
		if len(ss) != expectedLength {
			return nil, fmt.Errorf("%w: Invalid NFS transport stats 1.0 statement: %v", ErrFileParse, ss)
		}
	case statVersion11:
		var expectedLength int
		switch protocol {
		case "tcp":
			expectedLength = fieldTransport11TCPLen
		case "udp":
			expectedLength = fieldTransport11UDPLen
		case "rdma":
			expectedLength = fieldTransport11RDMAMinLen
		default:
			return nil, fmt.Errorf("%w: invalid NFS protocol \"%s\" in stats 1.1 statement: %v", ErrFileParse, protocol, ss)
		}
		if (len(ss) != expectedLength && (protocol == "tcp" || protocol == "udp")) ||
			(protocol == "rdma" && len(ss) < expectedLength) {
			return nil, fmt.Errorf("%w: invalid NFS transport stats 1.1 statement: %v, protocol: %v", ErrFileParse, ss, protocol)
		}
	default:
		return nil, fmt.Errorf("%w: Unrecognized NFS transport stats version: %q, protocol: %v", ErrFileParse, statVersion, protocol)
	}

	// Allocate enough for v1.1 stats since zero value for v1.1 stats will be okay
	// in a v1.0 response. Since the stat length is bigger for TCP stats, we use
	// the TCP length here.
	//
	// Note: slice length must be set to length of v1.1 stats to avoid a panic when
	// only v1.0 stats are present.
	// See: https://github.com/prometheus/node_exporter/issues/571.
	//
	// Note: NFS Over RDMA slice length is fieldTransport11RDMAMaxLen
	ns := make([]uint64, fieldTransport11RDMAMaxLen+3)
	for i, s := range ss {
		n, err := strconv.ParseUint(s, 10, 64)
		if err != nil {
			return nil, err
		}

		ns[i] = n
	}