‫مدیریت اسپم‌ها در SignalR

<HubName("chat")>
Public Class ChatHub
    Inherits Hub
    Public Sub sendMessage(msg As String) 
         Clients.All.getMessage(msg) 'Call getMessage function client side
    End Sub
End Class

Public Class ActivityInfo
    Sub New(connectionId As String)
        Me.ConnectionID = connectionId
        Me.Time = Now
    End Sub
    Public Property ConnectionID As String
    Public Property Time As DateTime
End Class

Public Class SpamDetectionPiplelineModule
    Inherits HubPipelineModule
    Public Property SpamDetection As New HashSet(Of ActivityInfo)
    Private _SpamDetectionLock As New Object
    Public Function IsSpam(ConnectionId As String) As Boolean
        SyncLock _SpamDetectionLock
            'Remove all old info before 3 seconds ago
            SpamDetection.RemoveWhere(Function(q) q.Time < Now.AddSeconds(-3))

            SpamDetection.Add(New ActivityInfo(ConnectionId))

            'Check activities from 3 seconds ago
            If SpamDetection.Where(Function(q) q.ConnectionID = ConnectionId).Count > 2 Then
                Return True
            Else
                Return False
            End If
        End SyncLock
    End Function
    Protected Overrides Function OnBeforeIncoming(context As IHubIncomingInvokerContext) As Boolean
        If IsSpam(context.Hub.Context.ConnectionId) Then
            Return False
        End If
        Return MyBase.OnBeforeIncoming(context)
    End Function
End Class

Public Class Startup
    Public Sub Configuration(app As IAppBuilder)
        GlobalHost.HubPipeline.AddModule(New SpamDetectionPiplelineModule)
        app.MapSignalR
    End Sub
End Class