Xojo Plugin

Receive a 4-byte Length Prefix from a Socket

See more Socket/SSL/TLS Examples

Demonstrates Socket.ReceiveCount, which reads a four-byte length prefix as a signed 32-bit integer. A return value of -1 indicates failure.

Background. Reading the length prefix first tells the application exactly how many bytes to read for the message body, which is a reliable way to know when a full message has arrived.

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Xojo Plugin

Dim success As Boolean
success = False

Dim socket As New Chilkat.Socket

//  Connect to the server using TLS.
Dim bTls As Boolean
bTls = True
Dim maxWaitMs As Int32
maxWaitMs = 5000
success = socket.Connect("example.com",5000,bTls,maxWaitMs)
If (success = False) Then
    System.DebugLog(socket.LastErrorText)
    Return
End If

//  Read a four-byte length prefix as a signed 32-bit integer (network byte order by default).  A
//  return value of -1 indicates failure.
Dim messageLength As Int32
messageLength = socket.ReceiveCount()
If (messageLength < 0) Then
    System.DebugLog(socket.LastErrorText)
    Return
End If

System.DebugLog("The peer will send " + Str(messageLength) + " bytes.")