Socket, connection handling changes

Enums: Removed noresponse enum, replaced with empty and unrecognized.
Socket:
- Modified Disconnect sub to have more concise parameter, remove unnecessary stream disposal
- Restructuring of core Query_Data subroutine. Moved or eliminated variable initialization, early sanity check for connection status, removed redundant newline in stream write, process response using .NET functions, move Enum parsing inline to subroutine, early check for null/empty response, distinct handling of good vs. bad results
- Removed unused Watchdog code (essentially became null/empty case in Query subroutine)
- Removed exception from Socket_Broken parameter
UPS:
- Stop variable update loop from calling Socket_Broken()
- In multi-variable get subroutine, only recurse on VARNOTSUPPORTED or STALE errors, everything else should be thrown.

Author: gbakeman

WinNUT_V2/WinNUT-Client_Common/Common_Enums.vb

@@ -61,7 +61,8 @@ End Enum
 
 ' Define possible responses according to NUT protcol v1.2
 Public Enum NUTResponse
-    NORESPONSE
+    EMPTY
+    UNRECOGNIZED
     OK
     VAR
     ACCESSDENIED

WinNUT_V2/WinNUT-Client_Common/Nut_Socket.vb

@@ -35,7 +35,7 @@ Public Class Nut_Socket
     ''' </summary>
     Private streamInUse As Boolean
 
-    Public Event Socket_Broken(ex As NutException)
+    Public Event Socket_Broken()
 
     Public Sub New(Nut_Config As Nut_Parameter, ByRef logger As Logger)
         LogFile = logger
@@ -122,9 +122,10 @@ Public Class Nut_Socket
     ''' <summary>
     ''' Perform various functions necessary to disconnect the socket from the NUT server.
     ''' </summary>
-    ''' <param name="forceful">Skip sending the LOGOUT command to the NUT server. Unknown effects.</param>
-    Public Sub Disconnect(Optional forceful = False)
-        If IsLoggedIn AndAlso Not forceful Then
+    ''' <param name="skipLogout">Do not send the LOGOUT command to the NUT server. Unknown effects.</param>
+    Public Sub Disconnect(Optional skipLogout = False)
+        If IsLoggedIn AndAlso Not skipLogout Then
+            ' TODO: Move to new subroutine.
             Query_Data("LOGOUT")
         End If
 
@@ -138,47 +139,11 @@ Public Class Nut_Socket
             ReaderStream.Dispose()
         End If
 
-        If NutStream IsNot Nothing Then
-            NutStream.Dispose()
-        End If
-
         If client IsNot Nothing Then
             client.Close()
         End If
     End Sub
 
-    ''' <summary>
-    ''' Parse and enumerate a NUT protocol response.
-    ''' </summary>
-    ''' <param name="Data">The raw response given from a query.</param>
-    ''' <returns></returns>
-    Private Function EnumResponse(Data As String) As NUTResponse
-        Dim Response As NUTResponse
-        ' Remove hyphens to prepare for parsing.
-        Dim SanitisedString = UCase(Data.Replace("-", String.Empty))
-        ' Break the response down so we can get specifics.
-        Dim SplitString = SanitisedString.Split(" "c)
-
-        Select Case SplitString(0)
-            Case "OK", "VAR", "DESC", "UPS"
-                Response = NUTResponse.OK
-            Case "BEGIN"
-                Response = NUTResponse.BEGINLIST
-            Case "END"
-                Response = NUTResponse.ENDLIST
-            Case "ERR"
-                Response = DirectCast([Enum].Parse(GetType(NUTResponse), SplitString(1)), NUTResponse)
-            Case "NETWORK", "1.0", "1.1", "1.2", "1.3"
-                'In case of "VER" or "NETVER" Query
-                Response = NUTResponse.OK
-            Case Else
-                ' We don't recognize the response, throw an error.
-                Response = NUTResponse.NORESPONSE
-                'Throw New Exception("Unknown response from NUT server: " & Response)
-        End Select
-        Return Response
-    End Function
-
     ''' <summary>
     ''' Attempt to send a query to the NUT server, and do some basic parsing.
     ''' </summary>
@@ -188,43 +153,59 @@ Public Class Nut_Socket
     ''' call is in progress.</exception>
     ''' <exception cref="NutException">Thrown when the NUT server returns an error or unexpected response.</exception>
     Function Query_Data(Query_Msg As String) As Transaction
-        Dim Response As NUTResponse
-        Dim DataResult As String
-        Dim finalTransaction As Transaction
+        If Not ConnectionStatus Then
+            Throw New InvalidOperationException("Attempted to send query " & Query_Msg & " while disconnected.")
+        End If
 
         If streamInUse Then
-            Throw New InvalidOperationException("Attempted to query " & Query_Msg & " while stream is in use.")
+            Throw New InvalidOperationException("Attempted to send query " & Query_Msg & " while stream is in use.")
         End If
 
-        If ConnectionStatus Then
+        Try
             streamInUse = True
+            WriterStream.WriteLine(Query_Msg)
+            WriterStream.Flush()
+        Catch
+            Throw
+        Finally
+            streamInUse = False
+        End Try
 
-            Try
-                WriterStream.WriteLine(Query_Msg & vbCr)
-                WriterStream.Flush()
-            Catch
-                Throw
-            Finally
-                streamInUse = False
-            End Try
+        Dim responseEnum = NUTResponse.EMPTY
+        Dim response = ReaderStream.ReadLine()
 
-            DataResult = Trim(ReaderStream.ReadLine())
-            Response = EnumResponse(DataResult)
-            finalTransaction = New Transaction(Query_Msg, DataResult, Response)
-
-            ' Handle error conditions
-            If DataResult = Nothing OrElse DataResult.StartsWith("ERR") Then
-                ' TODO: Does null dataresult really mean an error condition?
-                ' https://stackoverflow.com/a/6523010/530172
-                'Disconnect(True, True)
-                'RaiseEvent Socket_Broken(New NutException(Query_Msg, Nothing))
-                Throw New NutException(finalTransaction)
-            End If
+        If String.IsNullOrEmpty(response) Then
+            ' End of stream reached, likely server terminated connection.
+            Disconnect(True)
+            RaiseEvent Socket_Broken()
         Else
-            Throw New InvalidOperationException("Attempted to send query while disconnected.")
+            Dim parseResponse = response.Trim().ToUpper().Split(" "c) ' TODO: Is Trim unnecessary?
+
+            Select Case parseResponse(0)
+                Case "OK", "VAR", "DESC", "UPS"
+                    responseEnum = NUTResponse.OK
+                Case "BEGIN"
+                    responseEnum = NUTResponse.BEGINLIST
+                Case "END"
+                    responseEnum = NUTResponse.ENDLIST
+                Case "NETWORK", "1.0", "1.1", "1.2", "1.3"
+                    'In case of "VER" or "NETVER" Query
+                    responseEnum = NUTResponse.OK
+                Case "ERR"
+                    responseEnum = DirectCast([Enum].Parse(GetType(NUTResponse),
+                                                parseResponse(1).Replace("-", String.Empty)), NUTResponse)
+                Case Else
+                    responseEnum = NUTResponse.UNRECOGNIZED
+            End Select
         End If
 
-        Return finalTransaction
+        Dim transaction = New Transaction(Query_Msg, response, responseEnum)
+
+        If responseEnum = NUTResponse.OK OrElse responseEnum = NUTResponse.BEGINLIST OrElse responseEnum = NUTResponse.ENDLIST Then
+            Return transaction
+        End If
+
+        Throw New NutException(transaction)
     End Function
 
     Public Function Query_List_Datas(Query_Msg As String) As List(Of UPS_List_Datas)
@@ -351,12 +332,4 @@ Public Class Nut_Socket
             Throw New NutException(Nut_Query)
         End If
     End Function
-
-    Private Sub Event_WatchDog(sender As Object, e As EventArgs)
-        Dim Nut_Query = Query_Data("")
-        If Nut_Query.ResponseType = NUTResponse.NORESPONSE Then
-            Disconnect(True)
-            RaiseEvent Socket_Broken(New NutException(Nut_Query))
-        End If
-    End Sub
 End Class

WinNUT_V2/WinNUT-Client_Common/UPS_Device.vb

@@ -429,7 +429,6 @@ Public Class UPS_Device
         Catch Excep As Exception
             LogFile.LogTracing("Something went wrong in Retrieve_UPS_Datas:", LogLvl.LOG_ERROR, Me)
             LogFile.LogException(Excep, Me)
-            Socket_Broken()
         End Try
     End Sub
 
@@ -481,12 +480,10 @@ Public Class UPS_Device
                                 Continue For
                             End If
                         End If
-
                     Case Else
-                        LogFile.LogTracing("Error with " & varName & ", trying next", LogLvl.LOG_WARNING, Me)
-                        ' Continue to next variable
-                        Continue For
+                        Throw
                 End Select
+
             Catch ex As Exception
                 LogFile.LogTracing("Exception for variable " & varName & ": " & ex.Message & ", trying next", LogLvl.LOG_WARNING, Me)
                 ' Continue to next variable