Changeset 119 for Comm/UCommFrame.pas

Timestamp:

Jan 5, 2011, 1:16:30 PM (14 years ago)

Author:

george

Message:

• Created: New Lazarus package as container for few classes with bidirectional pin interconnection system .

Location:

Comm

Files:

• . (modified) (1 prop)
• UCommFrame.pas (modified) (9 diffs)

Comm/UCommFrame.pas

@@ -6 +6 @@
 
 uses
-  Classes, UMemoryStreamEx, Dialogs, SysUtils,
-  Forms, UCommPin;
+  Classes, UStreamHelper, Dialogs, SysUtils,
+  UCommPin;
 
 const
@@ -22 +22 @@
   private
     LastCharIsSpecialChar: Boolean;
-    ReceiveBuffer: TMemoryStreamEx;
+    ReceiveBuffer: TStreamHelper;
     FrameState: TFrameState;
     FFrameErrorCount: Integer;
@@ -31 +31 @@
     FrameDataPin: TCommPin;
     PacketLoss: Real;
-    procedure RawDataReceive(Stream: TStream);
-    procedure FrameDataReceive(Stream: TStream);
+    procedure RawDataReceive(Sender: TCommPin; Stream: TStream);
+    procedure FrameDataReceive(Sender: TCommPin; Stream: TStream);
     constructor Create;
     destructor Destroy; override;
@@ -46 +46 @@
 constructor TCommFrame.Create;
 begin
-  ReceiveBuffer := TMemoryStreamEx.Create;
+  ReceiveBuffer := TStreamHelper.Create;
   RawDataPin := TCommPin.Create;
   RawDataPin.OnReceive := RawDataReceive;
@@ -62 +62 @@
 end;
 
-procedure TCommFrame.FrameDataReceive(Stream: TStream);
+procedure TCommFrame.FrameDataReceive(Sender: TCommPin; Stream: TStream);
 var
-  RawData: TMemoryStreamEx;
+  RawData: TStreamHelper;
   I: Integer;
   Character: Byte;
@@ -75 +75 @@
   // Byte stuffing
   Stream.Position := 0;
-  RawData := TMemoryStreamEx.Create;
-  RawData.WriteByte(SpecialChar);
-  RawData.WriteByte(ControlCodeFrameStart);
-  for I := 0 to Stream.Size - 1 do begin
-    Character := TMemoryStreamEx(Stream).ReadByte;
+  try
+    RawData := TStreamHelper.Create;
+    RawData.WriteByte(SpecialChar);
+    RawData.WriteByte(ControlCodeFrameStart);
+    for I := 0 to Stream.Size - 1 do begin
+      Character := Stream.ReadByte;
+      if Character = SpecialChar then begin
+        RawData.WriteByte(SpecialChar);
+        RawData.WriteByte(ControlCodeSpecialChar);
+      end else RawData.WriteByte(Character);
+    end;
+
+    Character := CRC;
     if Character = SpecialChar then begin
       RawData.WriteByte(SpecialChar);
       RawData.WriteByte(ControlCodeSpecialChar);
     end else RawData.WriteByte(Character);
+
+    RawData.WriteByte(SpecialChar);
+    RawData.WriteByte(ControlCodeFrameEnd);
+    //if Random >= PacketLoss then
+      RawDataPin.Send(RawData);
+
+  finally
+    RawData.Free;
   end;
-
-  Character := CRC;
-  if Character = SpecialChar then begin
-    RawData.WriteByte(SpecialChar);
-    RawData.WriteByte(ControlCodeSpecialChar);
-  end else RawData.WriteByte(Character);
-
-  RawData.WriteByte(SpecialChar);
-  RawData.WriteByte(ControlCodeFrameEnd);
-  //if Random >= PacketLoss then
-    RawDataPin.Send(RawData);
-  RawData.Free;
 end;
 
-procedure TCommFrame.RawDataReceive(Stream: TStream);
+procedure TCommFrame.RawDataReceive(Sender: TCommPin; Stream: TStream);
 var
   Character: Byte;
@@ -107 +111 @@
 begin
   for I := 0 to Stream.Size - 1 do begin
-    Character := TMemoryStreamEx(Stream).ReadByte;
+    Character := Stream.ReadByte;
     if LastCharIsSpecialChar then begin
       if Character = ControlCodeSpecialChar then begin
@@ -115 +119 @@
           if FrameState = fsInside then
             Inc(FFrameErrorCount);
-          ReceiveBuffer.Clear;
+          ReceiveBuffer.Size := 0;
           FrameState := fsInside;
         end else
@@ -123 +127 @@
             if ReceiveBuffer.Size > 0 then begin
               ReceiveBuffer.Position := ReceiveBuffer.Size - 1;
-              CRC := TMemoryStreamEx(ReceiveBuffer).ReadByte;
+              CRC := ReceiveBuffer.ReadByte;
               ReceiveBuffer.Size := ReceiveBuffer.Size - 1;
               ExpectedCRC := GetStreamCRC8(ReceiveBuffer);