func DecodeOmp()

in nmxact/omp/omp.go [47:94]
41 lines of code
17 McCabe index (conditional complexity)

func DecodeOmp(m coap.Message, rxFilter nmcoap.RxMsgFilter) (nmp.NmpRsp, error) {
	// Ignore non-responses.
	if m.Code() == coap.GET || m.Code() == coap.PUT || m.Code() == coap.POST ||
		m.Code() == coap.DELETE {
		return nil, nil
	}

	if rxFilter != nil {
		var err error
		m, err = rxFilter.Filter(m)
		if err != nil {
			return nil, err
		}
	}

	if m.Code() != coap.Created && m.Code() != coap.Deleted &&
		m.Code() != coap.Valid && m.Code() != coap.Changed &&
		m.Code() != coap.Content {
		return nil, fmt.Errorf(
			"OMP response specifies unexpected code: %d (%s)", int(m.Code()),
			m.Code().String())
	}

	var om OicMsg
	err := codec.NewDecoderBytes(m.Payload(), new(codec.CborHandle)).Decode(&om)
	if err != nil {
		return nil, fmt.Errorf("Invalid incoming cbor: %s", err.Error())
	}
	if om.Hdr == nil {
		return nil, fmt.Errorf("Invalid incoming OMP response; NMP header" +
			"missing")
	}

	hdr, err := nmp.DecodeNmpHdr(om.Hdr)
	if err != nil {
		return nil, err
	}

	rsp, err := nmp.DecodeRspBody(hdr, m.Payload())
	if err != nil {
		return nil, fmt.Errorf("Error decoding OMP response: %s", err.Error())
	}
	if rsp == nil {
		return nil, nil
	}

	return rsp, nil
}