func readListHeader()

in internal/encoding/decode.go [333:373]

• 36 lines of code
• 9 McCabe index (conditional complexity)

func readListHeader(r *buffer.Buffer) (length int64, _ error) {
	type_, err := readType(r)
	if err != nil {
		return 0, err
	}

	listLength := r.Len()

	switch type_ {
	case TypeCodeList0:
		return 0, nil
	case TypeCodeList8:
		buf, ok := r.Next(2)
		if !ok {
			return 0, errors.New("invalid length")
		}
		_ = buf[1]

		size := int(buf[0])
		if size > listLength-1 {
			return 0, errors.New("invalid length")
		}
		length = int64(buf[1])
	case TypeCodeList32:
		buf, ok := r.Next(8)
		if !ok {
			return 0, errors.New("invalid length")
		}
		_ = buf[7]

		size := int(binary.BigEndian.Uint32(buf[:4]))
		if size > listLength-4 {
			return 0, errors.New("invalid length")
		}
		length = int64(binary.BigEndian.Uint32(buf[4:8]))
	default:
		return 0, fmt.Errorf("type code %#02x is not a recognized list type", type_)
	}

	return length, nil
}