read_stream() - message longer than RECV_BUFFER raises MLLPException('buffer not terminated...')

[massimiliano-della-rovere]

The read_stream function reads just one chunk of data that must be at most RECV_BUFFER bytes long.

This breaks when a message is longer than RECV_BUFFER. The fix is keeping on executing

data = stream.read(RECV_BUFFER)

and break if len(data) < RECV_BUFFER.

I will post a patch proposal soon.

[ii8]

The solution you propose is still incorrect. The client may receive less data than could fit in the provided buffer even if that is not the entire message sent as a response by the server, in which case the client should continue reading.

[elamathis18]

I'm having the same issue but when using mllp_send. Were you able to find any fixes?

[anibal2j]

I'd love to have a patch for this. I think the whole implementation of https://github.com/johnpaulett/python-hl7/blob/6d85f25d678e366d2617690d4ee1216bb8027db1/hl7/client.py#L82 MLLPClient.send() is faulty. I think something like this might work:

    #make socket non blocking
    the_socket.setblocking(0)
     
    #total data partwise in an array
    total_data=[];
    data='';
     
    #beginning time
    begin=time.time()
    while 1:
        #if you got some data, then break after timeout
        if total_data and time.time()-begin> timeout:
            break
         
        #if you got no data at all, wait a little longer, twice the timeout
        elif time.time()-begin> timeout*2:
            break
         
        #recv something
        try:
            data = the_socket.recv(8192)
            if data:
                total_data.append(data)
                #change the beginning time for measurement
                begin=time.time()
            else:
                #sleep for sometime to indicate a gap
                time.sleep(0.1)
        except:
            pass
     
    #join all parts to make final string
    return''.join(total_data)

But I tried the above and it's still not fully working. But you get the idea, where there's a loop around the recv call from the socket to keep receiving data, that may come in chunks from the server.