Sending a protobuf C++ serialized string over ZeroMQ and parsing using python

Question

C++ serialization:

int main ()
{
    GOOGLE_PROTOBUF_VERIFY_VERSION;

    proto::Request request;
    std::string output;

    request.set_fieldone("X");
    request.set_fieldtwo("Y");

    //  Prepare our context and socket
    zmq::context_t context (1);
    zmq::socket_t socket (context, ZMQ_REQ);
    socket.connect ("tcp://localhost:5555");

    request.SerializeToString(&output);

    long size = output.length();
    zmq::message_t request(size);
    memcpy(request.data(), &output, size);

    socket.send(request);

    return 0;

}

Python de-serialization:

def __init__(self):
    self.database.connect()
    self.context = zmq.Context()
    self.socket = self.context.socket(zmq.REP)
    self.socket.bind("tcp://*:5555")
    self.request = call_init_pb2.DialRequest()

def run(self):
    message = self.socket.recv()
    self.request.ParseFromString(message)

Which gives me the error message:

self.request.ParseFromString(message)
google.protobuf.message.DecodeError: Error parsing message

What I would like to achieve is to serialize the message in C++, send it over a network to a Python server. De-serialize the message, and then perform some business logic on the server side to check for certain properties of the message. I can send the string, and its received with the same length and type at the Python server side, but the parsing doesn't work.

Did I miss some fundamental basic knowledge?

user3666197 · Accepted Answer · 2017-06-24 17:22:02Z

1

I solved this issue, using SerializeToArray rather than SerializeToString approach.

Here is the code I found from https://groups.google.com/forum/#!topic/protobuf/AmdloRxdFUg which solved this "issue"

 int size = request.ByteSize();
 char* array = new char[size];
 request.SerializeToArray(array, size);

edited Jun 24, 2017 at 17:22

user3666197

1

answered Jun 22, 2017 at 19:41

Anticipating

1411 gold badge4 silver badges13 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Sending a protobuf C++ serialized string over ZeroMQ and parsing using python

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related