func()

in nmxact/mtech_lora/mtech_lora_xport.go [164:256]
85 lines of code
15 McCabe index (conditional complexity)

func (lx *LoraXport) reass(dev string, port uint8, data []byte) {
	lx.Lock()
	defer lx.Unlock()

	var err error
	_, l := lx.reassMap.FindListener(dev, port, "reass")
	if l == nil {
		_, l = lx.msgMap.FindListener("", port, "req")
		if l == nil {
			log.Debugf("No LoRa listener for %s", dev)
			return
		}
		lx.Unlock()
		s, err := lx.acceptServerSesn(l, dev, port)
		lx.Lock()
		if err != nil {
			log.Errorf("Cannot create server sesn: %v", err)
			return
		}
		l = s.reassListener
	}

	str := hex.Dump(data)

	log.Debugf("Raw data: %s", str)
	bufR := bytes.NewReader(data)

	var frag lora.CoapLoraFrag
	var sFrag lora.CoapLoraFragStart

	err = binary.Read(bufR, binary.LittleEndian, &frag)
	if err != nil {
		log.Debugf("Can't read header")
		return
	}

	fragNum := frag.FragNum &^ lora.COAP_LORA_LAST_FRAG
	if l.Data.Len() == 0 {
		if fragNum != 0 {
			log.Debugf("frag num != 0 with empty queue")
			return
		}
		bufR.Seek(0, 0)
		err = binary.Read(bufR, binary.LittleEndian, &sFrag)
		if err != nil {
			log.Debugf("Can't read in start header")
			return
		}
		l.Crc = sFrag.Crc
		l.Data.Write(data[3:])
		l.NextFrag = 1
	} else {
		if fragNum != l.NextFrag {
			log.Debugf("Frag out of sequence")
			l.Data.Reset()
			return
		}
		l.Data.Write(data[1:])
		l.NextFrag++
	}

	if (frag.FragNum & lora.COAP_LORA_LAST_FRAG) != 0 {
		data := l.Data.Bytes()
		l.Data.Reset()

		code := coap.COAPCode(data[1])
		if code <= coap.DELETE {
			_, l = lx.msgMap.FindListener(dev, port, "req")
			if l == nil {
				_, l = lx.msgMap.FindListener("", port, "req")
				if l == nil {
					log.Debugf("No LoRa listener for %s", dev)
					return
				}
				lx.Unlock()
				s, err := lx.acceptServerSesn(l, dev, port)
				lx.Lock()
				if err != nil {
					log.Errorf("Cannot create server sesn: %v", err)
					return
				}
				l = s.msgListener
			}
		} else {
			_, l = lx.msgMap.FindListener(dev, port, "rsp")
		}
		if l != nil {
			l.MsgChan <- data
		} else {
			log.Debugf("No LoRa listener for %s", dev)
		}
	}
}