def startUdpListenerBin()

in python/awsgs.py [0:0]
55 lines of code
12 McCabe index (conditional complexity)

def startUdpListenerBin(listenerPort, bufferSize, outputFile):

    #   Starts a UDP server and writes received data to a file

    localIP             = "127.0.0.1"
    numPacketsReceived  = 0
    numPacketsProcessed = 0
    totalDataSize       = 0
    inMemoryPayload     = b''
    outputMessageEveryNPackets = 1000

    try:
        UDPServerSocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        #   Set the socket timeout to 10 seconds
        UDPServerSocket.settimeout(10)
        #UDPServerSocket.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 3000000)
        UDPServerSocket.bind((localIP, listenerPort))
        print("\nUDP server listening on %s:%s" % (localIP, listenerPort) )
        print("Output file: %s\n" % (outputFile))
    except Exception as e:

        if e.errno == 1:
            print(" (ERR) [ERROR_ROOT_REQUIRED] Socket open error: %s" % e )
        else:
            print(" (ERR) [ERROR_CANT_OPEN_SOCKET] Socket open error: %s" % e )
        return 0

    #   Open file handle
    try:
        f = open(outputFile, "wb", buffering=bufferSize)
    except Exception as e:
        print(" (ERR) File open error: %s" % e )
        return 0

    while(True):

        #   Read data into string
        try:
            bytesAddressPair = UDPServerSocket.recvfrom(bufferSize)

            message = bytesAddressPair[0]
            #address = str(bytesAddressPair[1][0])

            #appendToRawFile(outputFile, message)

            numPacketsReceived += 1

            payloadLength = 0
            payload = extractVrtPayloadFromBin(message)
            #   left to test if above function is causing the receive buffer issues
            #payload = message
            payloadLength = len(payload)

            if payloadLength < 1:
                print("[%d] Packet not a valid VITA 49 format" % numPacketsReceived)

            else:

                numPacketsProcessed += 1

                #   Add payload to inMemory payload chunk
                inMemoryPayload = inMemoryPayload + payload

                #   Print out message every 1000 packets
                #   If we print on ever packet STDOUT cant keep up
                #if numPacketsProcessed % outputMessageEveryNPackets == 0 or numPacketsReceived == 1:
                #    print("[%d] Receiving Data. Total payload %d Bytes" % (numPacketsReceived, len(inMemoryPayload)) )

        except socket.timeout:

            if len(inMemoryPayload) > 0:

                #   Write received data to file
                try:
                    print("Writing memory buffer to output file...")
                    #f = open(outputFile, "ab", buffering=8192)
                    num_bytes_written = f.write(inMemoryPayload)

                    #   Make sure the buffer is flushed correctly
                    f.flush()
                    os.fsync(f.fileno())

                    #   Clear the memory buffer
                    inMemoryPayload = b''

                    print("%d Payload Bytes written from %d packets" % (num_bytes_written, numPacketsProcessed) )
                    totalDataSize += num_bytes_written

                except Exception as e:
                    print("(ERR) File write error: %s" % e )
                    return 0

            print('')
            print('Status Update:')
            print(" %d packets received" % (numPacketsReceived))
            print(" %d packets processed successfully" % (numPacketsProcessed))
            print(" %d Total Bytes written to %s" % (totalDataSize, outputFile))