UWP, how to read ALL data from StreamSocket

Question

I'm trying to implement a XMPP client for UWP in C# and to achieve this I'm using StreamSocket for TCP connection.

The problem is that for handshake and SASL auth I need a sequence of "writing and reading" from the client by the server and without a delay I can't read all data sent by server; I want to remove the delay part.

This is my code:

// Start handshake
await XmppWrite("<?xml version='1.0'?><stream:stream to='" + serverHostName.Domain + "' xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams' version='1.0'>");
var responseStream = await XmppRead();

SaslPlain saslPlain = new SaslPlain(Username, Password);
responseStream = null;
String xml = null;
while (!saslPlain.IsCompleted && (xml = saslPlain.GetNextXml(responseStream)) != null)
{
    await XmppWrite(xml);
    responseStream = await XmppRead();
}
if (!saslPlain.IsSuccess) return;

// Request bind
await XmppWrite("<?xml version='1.0'?><stream:stream to='" + serverHostName.Domain + "' xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams' version='1.0'>");
responseStream = await XmppRead();

// Bind
await XmppWrite("<iq id='" + GenerateId() + "' type='set'><bind xmlns='urn:ietf:params:xml:ns:xmpp-bind'/></iq>");
responseStream = await XmppRead();
if (responseStream.Jid == null) return;

Jid = responseStream.Jid;

// Open session
await XmppWrite("<iq id='" + GenerateId() + "' type='set'><session xmlns='urn:ietf:params:xml:ns:xmpp-session'/></iq>");
responseStream = await XmppRead();

The XmppRead() method is this:

private async Task<XmppStream> XmppRead()
{
    await Task.Delay(100); // Things don't works without this...
    var x = await dataReader.LoadAsync(BUFFER_SIZE);
    if (dataReader.UnconsumedBufferLength > 0)
    {
        Debug.WriteLine(x + ", " + dataReader.UnconsumedBufferLength);
        var stream = new XmppStream(dataReader.ReadString(dataReader.UnconsumedBufferLength));
        if (stream.IsError)
        {
            if (Error != null)
            {
                Error(this, new XmppClientEventArgs(stream));
            }
            throw new Exception(stream.Error);
        }
        return stream;
    }
    return new XmppStream();
}

So, I think the problem is that i try to read before the server has finished to send all its data, so I can read only a partial message. How can i check if there are some other data without block?

Thanks.

score 0 · Answer 1 · answered Jun 06 '18 at 00:22

(I was searching for something else and saw this question)

What happens when you set the DataReader.InputOptions to Partial? Right now the LoadAsync (AFAICT) won't return it's got all BUFFER_SIZE bytes. By setting the input stream options to partial, you'll get whatever is available.

DataReader docs are here and InputStreamOptions value are here

UWP, how to read ALL data from StreamSocket

1 Answers1