How to send QMap over socket?

Question

I have a QMap object:

QMap<QString, int> map; 

and I would like to send it over TCP socket. Do I have to convert it to JSON and then send it or?

Answer 1

Try to use this approach:

On Server side use this to send a map:

// to send Map
qint64 SendMap(QMap<String, int> map){
    QByteArray block;
    QDataStream sendStream(&block, QIODevice::ReadWrite);

    sendStream << quint64(0) // for size of data
               << map;       // your map

    sendStream.device()->seek(0); // return back to set data size

    sendStream << (quint64)(block.size() - sizeof(quint64)); // set data size

    return socket->write(block);    // send data
}

On Client side, when you expect a map, use this to read a map:

// to receive Map
QMap<QString, int> ReceiveMap(QTcpSocket *socket){
    QDataStream readStream(socket);
    quint64 dataBlockSize = 0;

    while(true) {
        if (!dataBlockSize) {
            if (socket->bytesAvailable() < sizeof(quint64)) { // waiting data size 
                break;                                        // to be available
            }
            readStream >> dataBlockSize;
        }

        if (socket->bytesAvailable() < dataBlockSize) { // waiting full data
            break;
        }

        QMap<QString, int> map;
        readStream >> map;

        return map;
    }
}