{= COMMON.INC ===========================================================
|
| Common Type and procedure declarations for EXPORT.PAS, IMPORT.PAS and
| UPDATE.PAS.
|
|========================================================================}
TYPE
  { Conversion Table Types }
  ConversionType = RECORD
    NodeSide   : Byte;
    HubSide    : Byte;
  END; { RECORD }

  ConversionTableType = ARRAY [1..255] OF ConversionType;

  { Sample Pointer Table Types }
  PointerArrayType            = ARRAY [0..255] OF Integer;

  PointerFileType             = FILE OF PointerArrayType;

{------------------------------------------------------------------------
|
|
|------------------------------------------------------------------------}
FUNCTION ReadConversionTable (VAR ConversionTable  : ConversionTableType;
                              VAR ConversionCount  : Byte;
                                  SystemId         : String;
                                  SystemType       : Char) : Boolean;

VAR
  F                           : Text;
  Name                        : String;
  Junk                        : String;

BEGIN
  FillChar (ConversionTable, SizeOf(ConversionTable), #0);
  IF SystemType = 'N' THEN BEGIN
    Name:= SystemId + '.HUB';
    Assign (F, Junk);
  END
  ELSE BEGIN
    Name:= SystemId + '.NOD';
    Assign (F, Junk);
  END;

  {$I-} Reset (F); {$I-}
  IF IOResult <> 0 THEN BEGIN
    Writeln (^g^g'Error opening ',Name,'!');
    Halt;
  END;

  { Get rid of the password line }
  {$I-} Readln (F, Junk); {$I+}
  IF IOResult <> 0 THEN BEGIN
    Writeln (^g^g'Error reading ',Name,'!');
    Halt;
  END;

  ConversionCount:= 0;

  WHILE (NOT Eof(F)) AND (ConversionCount <= 255) DO BEGIN
    Inc (ConversionCount);
    {$I-}
    Read (F, ConversionTable[ConversionCount].NodeSide);
    Readln (F, ConversionTable[ConversionCount].HubSide);
    {$I+}
    IF IOResult <> 0 THEN BEGIN
      Writeln (^g^g'Error reading ',Name,'!');
      Halt;
    END;

  END;

  Close (F);
  {$I-}
  ReadConversionTable:= (IOResult = 0);
END;

{------------------------------------------------------------------------
|
|
|------------------------------------------------------------------------}
PROCEDURE LocalAreaNumber (VAR MatchFound       : Boolean;
                           VAR LocalAreaNumber  : Byte;
                               RemoteAreaNumber : Byte;
                               SystemType       : Char;
                           VAR ConversionTable  : ConversionTableType;
                           VAR ConversionCount  : Byte);

VAR
  Match                       : Byte;
  I                           : Byte;

BEGIN
  MatchFound:= True;
  LocalAreaNumber:= 0;
  { IF the RemoteAreaNumber is 0 there is no conversion needed }
  IF RemoteAreaNumber = 0 THEN Exit;

  Match:= 0;
  FOR I:= 1 TO ConversionCount DO BEGIN
    CASE SystemType OF
      'N' : IF ConversionTable[I].NodeSide = RemoteAreaNumber THEN
              Match:= I;
      'H' : IF ConversionTable[I].HubSide  = RemoteAreaNumber THEN
              Match:= I;
    END;
  END;

END;

{- ReadPointer ----------------------------------------------------------
|
|
|------------------------------------------------------------------------}
FUNCTION ReadPointer (    SystemName    : String;
                      VAR MsgPointer    : PointerArrayType) : Boolean;

VAR
  Error                       : Word;
  F                           : PointerFileType;

BEGIN
  Assign (F, SystemName + '.PTR');
  {$I-}
  Reset (F);
  Error:= IOResult;
  IF Error = 0 THEN BEGIN
    Read (F, MsgPointer);
    Error:= IOResult;
    IF Error = 0 THEN Close (F);
    Error:= IOResult;
  END;
  ReadPointer:= (Error = 0);
  {$I+}
END;

{- WritePointer ---------------------------------------------------------
|
| Writes the memory pointer array to Disk specified by the SystemName.
|
|------------------------------------------------------------------------}
FUNCTION WritePointer (    SystemName    : String;
                       VAR MsgPointer    : PointerArrayType) : Boolean;

VAR
  Error                       : Word;
  F                           : PointerFileType;

BEGIN
  Assign (F, SystemName + '.PTR');
  {$I-}
  Rewrite (F);
  Error:= IOResult;
  IF Error = 0 THEN BEGIN
    Write (F, MsgPointer);
    Error:= IOResult;
    IF Error = 0 THEN Close (F);
    Error:= IOResult;
  END;
  WritePointer:= (Error = 0);
  {$I+}
END;

{------------------------------------------------------------------------
|
|
|------------------------------------------------------------------------}
PROCEDURE ZeroPointer (VAR MsgPointer   : PointerArrayType);

VAR
  I                           : Integer;

BEGIN
  FOR I:= 0 TO 255 DO
    MsgPointer[I]:= 0;
END;