NetworkStream.Read doesn't get all the data.

[SDittmar]

This is what im basically doing

 

-

Dim tcp as New TcpClient

tcp.Connect("host",80)

 

Dim ns as NetworkStream = tcp.GetStream

dim size as integer

 

While ns.DataAvailable

size = ns.read(buffer,0,buffer.length)

End While

-

 

How do i wait for all the data to be received? Because i end up getting only some of the data then the loop ends.

 

thanx for any replies

[Derek Stone]

You're overwriting the buffer you've created everytime the contents of the While/End While block execute. Try appending the contents of the newly filled buffer to a variable that isn't going to be overwritten.

[SDittmar]

that was only an example of what im doing, here the actual thing:

 

Dim size As Integer
       Dim all() As Byte = New Byte() {}
       Dim current() As Byte = New Byte(8191) {}
       Dim timeout As Single
       Dim res As New NNTPResponse()
       Dim x As Integer
       Dim stream As NetworkStream = _tcp.GetStream

       While Not stream.DataAvailable Or CInt(timeout) = _timeout
           Sleep(500)
           timeout += 0.5
       End While

       If timeout = _timeout Then
           _timedout = True
           Exit Function
       End If


       While stream.DataAvailable
           size = stream.Read(current, 0, current.Length)
           Debug.Write(size & vbCrLf)
           ReDim Preserve current(size - 1)
           ReDim Preserve all(all.Length + size - 1)
           Array.Copy(current, 0, all, all.Length - size, current.Length)
           ReDim current(8191)
       End While

Edited February 24, 2003 by divil

[SDittmar]

It seems to work fine in debug mode (obviously because it has more time to receive data) but not normally. What property can i use to wait for the typical 8192 bytes?

 

thanx

[a_jam_sandwich]

if I was you i'd have a time out of perhaps 30secs

 

Andy

[Derek Stone]

Your timing scheme is flawed. Instead of telling the current thread to sleep for 500 milliseconds the code should keep polling the DataAvailable property until data is either present or the procedure times out.

[a_jam_sandwich]

quite true use the timer control so on each tick it checks

 

Andy

[Derek Stone]

A timer control is largely unnecessary. Use the Environment.TickCount property instead.

[Heiko]

Excuse me for interfering,

but to my understanding the code does exactly what Derek proposed: Polling the Dataavailable property until either data is present or the procedure times out.

 

There's just a short delay between the polls, and rightly so, I believe, in order not to grab all cpu power for this busy waiting.

 

my 2c

[Heiko]

Dim size As Integer
Dim all() As Byte = New Byte() {}
Dim current() As Byte = New Byte(8191) {}
Dim timeout As Single
Dim res As New NNTPResponse()
Dim x As Integer
Dim stream As NetworkStream = _tcp.GetStream

' BEGIN OUTER LOOP

While Not stream.DataAvailable Or CInt(timeout) = _timeout
Sleep(500)
timeout += 0.5
End While

If timeout = _timeout Then
_timedout = True
Exit Function
End If

While stream.DataAvailable
size = stream.Read(current, 0, current.Length)
Debug.Write(size & vbCrLf)
ReDim Preserve current(size - 1)
ReDim Preserve all(all.Length + size - 1)
Array.Copy(current, 0, all, all.Length - size, current.Length)
ReDim current(8191)
End While

' Reset Timeout
' END OUTER LOOP