Network send problem

I try to send data over the network, but the server I've programmed doesen't get the data. This code worked befor:

void MainWindow::send()
{
 QByteArray qbarr;
 QDataStream qdstrm(&qbarr, QIODevice::WriteOnly);
 int iCount = qlist->count();
 QProgressDialog qprogrsdSend(QString("Sending..."), QString("Cancel"), 0, iCount, this);

 qdstrm.setVersion(QDataStream::Qt_4_6);

 qprogrsdSend.setWindowModality(Qt::WindowModal);

 for(int i = 0; i < iCount; i++)
 {
  if(qprogrsdSend.wasCanceled())
   break;

  qdstrm << (quint16)0;
  qdstrm << (*qlist)[i].data();
  qdstrm.device()->seek(0);
  qdstrm << (quint16)(qbarr.size() - sizeof(quint16));

  qprogrsdSend.setV开发者_JAVA百科alue(i);

  qtcpsoClient->write(qbarr);
  qtcpsoClient->flush();
  qtcpsoClient->waitForBytesWritten();

  qbarr.clear();
 }

 qlblStatus2->setText("File is send.");
}

But it Takes to many time to send each elemt from qlist. Now I tried to modify the methode, so that first all elements from qlist has been saved in qbarr. And than I send the File. This is the code that doesnt work:

void MainWindow::send()
{
 QByteArray qbarr;
 QDataStream qdstrm(&qbarr, QIODevice::WriteOnly);
 int iCount = qlist->count();
 QProgressDialog qprogrsdSend(QString("Sending..."), QString("Cancel"), 0, iCount, this);

 qdstrm.setVersion(QDataStream::Qt_4_6);

 qprogrsdSend.setWindowModality(Qt::WindowModal);

 qdstrm << (quint16)0;

 for(int i = 0; i < iCount; i++)
 {
  if(qprogrsdSend.wasCanceled())
   break;

  qdstrm << (*qlist)[i].data();

  qprogrsdSend.setValue(i);
 }

 qdstrm.device()->seek(0);
 qdstrm << (quint16)(qbarr.size() - sizeof(quint16));

 qtcpsoClient->write(qbarr);
 qtcpsoClient->flush();
 qtcpsoClient->waitForBytesWritten();

 qbarr.clear();

 qlblStatus2->setText("File is send.");
}

And here is the methode I use to read the data:

void QServerThread::onReadyRead(void)
{
 if(read == false)
 {
  read = true;
  emit reading(true);
 }

 while(!qtcpsoClient->atEnd())
 {
  QDataStream qdstrmIn(qtcpsoClient);
  QDataStream qdstrmOut(qfile);
  QByteArray qbarrData;
  quint16 qui16BlockSize = 0;
  int iVersion = qdstrmIn.version();

  qdstrmIn.setVersion(iVersion);
  qdstrmOut.setVersion(iVersion);

  if(qtcpsoClient->bytesAvailable() < (int)sizeof(quint16))
   break;

  qdstrmIn >> qui16BlockSize;

  if(qtcpsoClient->bytesAvailable() < qui16BlockSize)
   break;

  qdstrmIn >> qbarrData;

  qdstrmOut << qbarrData.data();

  qfile->flush();
 }

 read = false;
 emit reading(false);
}

I hope somebody can help me. Thanks

Paul

Couldn't the problem be in your server? I suppose you connect your onReadyRead to readyRead singal of the socket. That signal is emitted once per a chunk of data received. So if you send all your data at once, it is possible the signal gets emitted only once. I suppose qtcpsoClient is the socket. Now, I can see this happening:

You ask bytesAvailable() < somesize before that much data arrived yet. In that case you read a size, but break out right after that and on next read you already lost your size information and read garbage.

This might not be a problem before as you send multiple short messages, and every message managed to fully arrive before you asked for the data size. The bug was still there though.

On a sidenote. In your original client code - why did you flush() and waitForBytesWritten() after every write? This may be the reason why it was so slow.

[edit: corrected based on Sergey Tachenov's comment]