Changeset 16

Timestamp:

Mar 30, 2010, 11:23:20 AM (15 years ago)

Author:

george

Message:

• Upraveno: Přidána podpora pro endianicitu číselných typů.
• Přidáno: Metody pro zápis a čtení typů Double a Single.

File:

• MemoryStreamEx/UMemoryStreamEx.pas (modified) (9 diffs)

MemoryStreamEx/UMemoryStreamEx.pas

@@ -1 +1 @@
 unit UMemoryStreamEx;
+
+{$mode delphi}{$H+}
 
 interface
@@ -7 +9 @@
 
 type
+  TEndianness = (enBig, enLittle);
+  
+  { TMemoryStreamEx }
+
   TMemoryStreamEx = class(TMemoryStream)
+  private
+    FEndianness: TEndianness;
+    SwapData: Boolean;
+    procedure SetEndianness(const AValue: TEndianness);
+  public
     procedure WriteByte(Data: Byte);
     procedure WriteWord(Data: Word);
@@ -13 +24 @@
     procedure WriteInt64(Data: Int64);
     procedure WriteShortString(Data: ShortString);
+    procedure WriteAnsiString(Data: string);
     procedure WriteUnixTime(Data: TDateTime);
-    procedure WriteStream(Stream: TStream);
+    procedure WriteStream(Stream: TStream; Count: Integer);
+    procedure WriteDouble(Value: Double);
+    procedure WriteSingle(Value: Single);
     function ReadByte: Byte;
     function ReadWord: Word;
@@ -20 +34 @@
     function ReadInt64: Int64;
     function ReadShortString: string;
+    function ReadAnsiString: string;
     function ReadUnixTime: TDateTime;
+    function ReadDouble: Double;
+    function ReadSingle: Single;
     procedure ReadStream(var Stream: TStream; Count: Integer);
+    constructor Create;
+    property Endianness: TEndianness read FEndianness write SetEndianness;
   end;
 
@@ -28 +47 @@
 { TMemoryStreamEx }
 
+procedure TMemoryStreamEx.WriteAnsiString(Data: string);
+var
+  StringLength: Longint;
+begin
+  StringLength := Length(Data);
+  Write(StringLength, SizeOf(StringLength));
+  Write(Data[1], StringLength);
+end;
+
+function TMemoryStreamEx.ReadAnsiString: string;
+var
+  StringLength: Longint;
+begin
+  Read(StringLength, SizeOf(StringLength));
+  SetLength(Result, StringLength);
+  if StringLength > 0 then begin
+    Read(Result[1], StringLength);
+  end;
+end;
+
 function TMemoryStreamEx.ReadByte: Byte;
 begin
-  Read(Result, 1);
+  Read(Result, SizeOf(Byte));
 end;
 
 function TMemoryStreamEx.ReadCardinal: Cardinal;
 begin
-  Read(Result, 4);
+  Read(Result, SizeOf(Cardinal));
+  if SwapData then Result := Swap(Result);
 end;
 
 function TMemoryStreamEx.ReadInt64: Int64;
 begin
-  Read(Result, 8);
+  Read(Result, SizeOf(Int64));
+  if SwapData then Result := Swap(Result);
 end;
 
@@ -65 +106 @@
 end;
 
+constructor TMemoryStreamEx.Create;
+begin
+  Endianness := enLittle;
+end;
+
 function TMemoryStreamEx.ReadUnixTime: TDateTime;
 begin
@@ -70 +116 @@
 end;
 
+function TMemoryStreamEx.ReadDouble: Double;
+begin
+  Read(Result, SizeOf(Double));
+end;
+
+function TMemoryStreamEx.ReadSingle: Single;
+begin
+  Read(Result, SizeOf(Single));
+end;
+
 function TMemoryStreamEx.ReadWord: Word;
 begin
-  Read(Result, 2);
+  Read(Result, SizeOf(Word));
+  if SwapData then Result := Swap(Result);
+end;
+
+procedure TMemoryStreamEx.SetEndianness(const AValue: TEndianness);
+begin
+  FEndianness := AValue;
+  {$ifdef FPC_LITTLE_ENDIAN}
+  SwapData := FEndianness = enBig;
+  {$elseifdef FPC_BIG_ENDIAN}
+  SwapData := FEndianness = enLittle;
+  {$endif}
 end;
 
 procedure TMemoryStreamEx.WriteByte(Data: Byte);
 begin
-  Write(Data, 1);
+  Write(Data, SizeOf(Byte));
 end;
 
 procedure TMemoryStreamEx.WriteCardinal(Data: Cardinal);
 begin
-  Write(Data, 4);
+  if SwapData then Data := Swap(Data);
+  Write(Data, SizeOf(Cardinal));
 end;
 
 procedure TMemoryStreamEx.WriteInt64(Data: Int64);
 begin
-  Write(Data, 8);
+  if SwapData then Data := Swap(Data);
+  Write(Data, SizeOf(Int64));
 end;
 
@@ -93 +162 @@
 begin
   WriteByte(Length(Data));
-  Write(Data[1], Length(Data))
-end;
-
-procedure TMemoryStreamEx.WriteStream(Stream: TStream);
+  Write(Data[1], Length(Data));
+end;
+
+procedure TMemoryStreamEx.WriteStream(Stream: TStream; Count: Integer);
 var
   Buffer: array of Byte;
 begin
+  if Count > Stream.Size then Count := Stream.Size; // Limit max. stream size
   Stream.Position := 0;
-  SetLength(Buffer, Stream.Size);
-  Stream.Read(Buffer[0], Stream.Size);
-  Write(Buffer[0], Stream.Size);
+  if Count > 0 then begin
+    SetLength(Buffer, Count);
+    Stream.Read(Buffer[0], Count);
+    Write(Buffer[0], Count);
+  end;
+end;
+
+procedure TMemoryStreamEx.WriteDouble(Value: Double);
+begin
+  Write(Value, SizeOf(Double));
+end;
+
+procedure TMemoryStreamEx.WriteSingle(Value: Single);
+begin
+  Write(Value, SizeOf(Single));
 end;
 
@@ -111 +193 @@
 begin
   DataUnix := DateTimeToUnix(Data);
-  Write(DataUnix, 4);
+  WriteCardinal(DataUnix);
 end;
 
 procedure TMemoryStreamEx.WriteWord(Data: Word);
 begin
-  Write(Data, 2);
+  if SwapData then Data := Swap(Data);
+  Write(Data, SizeOf(Word));
 end;