QNetworkReply and QNetworkAccessManager timeout in http request

Question

How do I setup a timeout when I do an http request?

I have this code:

{
    QNetworkRequest request;

    request.setUrl(QUrl("http://www.foo.com"));
    request.setRawHeader("User-Agent", USER_AGENT.toUtf8());
    request.setRawHeader("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.7");
    request.setRawHeader("Accept",
        "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
    request.setRawHeader("Accept-Language", "en-us,en;q=0.5");
    request.setRawHeader("Connection", "Keep-Alive");

    reply = m_networkManager->get(request);
    QEventLoop loop;
    connect(reply, SIGNAL(finished()), &loop, SLOT(quit()));
    loop.exec();
}

Where and how do I setup some kind of timeout to the request?

Striped

I am using m_networkManager->setTransferTimeout(30000) – Blanco

Answer 1

QTimer timer;    
timer.setSingleShot(true);

QEventLoop loop;
connect(&timer, SIGNAL(timeout()), &loop, SLOT(quit()));
connect(reply, SIGNAL(finished()), &loop, SLOT(quit()));
timer.start(30000);   // 30 secs. timeout
loop.exec();

if(timer.isActive()) {
    timer.stop();
    if(m_reply->error() > 0) {
      ... // handle error
    }
    else {      
      int v = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

      if (v >= 200 && v < 300) {  // Success
        ...
      }
    }
} else {
   // timeout
   disconnect(reply, SIGNAL(finished()), &loop, SLOT(quit()));

   reply->abort();
}

Clavier

Don't forget to delete the reply. – Hermineherminia

With download file process, with big file we need timeout bigger? Solution for this case? – Degression

@kienbui No. There are separate signals for this, e.g. bytesAvailable or uploadProgress – Vinic

We can vote "add builtin support for network timeouts" at here: bugreports.qt.io/browse/QTBUG-3443 – Degression

this is a brilliant solution @Clavier – Rotary

Answer 2

check this out:

https://doc.qt.io/qt-5/qnetworkrequest.html#setTransferTimeout

void QNetworkRequest::setTransferTimeout(int timeout = DefaultTransferTimeoutConstant) Sets timeout as the transfer timeout in milliseconds.

Transfers are aborted if no bytes are transferred before the timeout expires. Zero means no timer is set. If no argument is provided, the timeout is QNetworkRequest::DefaultTransferTimeoutConstant. If this function is not called, the timeout is disabled and has the value zero.

This function was introduced in Qt 5.15.

Snowinsummer