Plugins: Datenaustausch zwischen DLL und Hauptprogramm

[himitsu]

drum sagte ich ja, daß man diese eventuell noch implementieren muß
(hatte es vorhin nur nicht gemacht, da ich alles Vorhandene erstmal nur zusammenkopiert hatte und nichts direkt "neu" schrieb)

Delphi-Quellcode:

type
  IDelphiStreamIntern = interface
    {private}
    function GetPosition: Int64;
    procedure SetPosition(const Pos: Int64);
    procedure SetSize64(const NewSize: Int64);
    function GetSize: Int64;
  end;
  IDelphiStream = interface(IDelphiStreamIntern)
    ['{65805750-623E-4719-AD79-A30FF6FCA3CA}']
    procedure SetSize(NewSize: Longint);
    function Write(const Buffer; Count: Longint): Longint;
    function Read(var Buffer; Count: Longint): Longint;
    function Seek(Offset: Longint; Origin: Word): Longint;
    procedure Clear;
    procedure LoadFromStream(Stream: IDelphiStream);
    procedure SaveToStream(Stream: IDelphiStream);
    procedure LoadFromFile(const FileName: WideString);
    procedure SaveToFile(const FileName: WideString);
    property Position: Int64 read GetPosition write SetPosition;
    property Size: Int64 read GetSize write SetSize64;
  end;

  TInterfacedMemoryStream = class(TMemoryStream, IDelphiStream, IInterface)
  private
    function GetPosition: Int64;
    procedure SetPosition(const Pos: Int64);
    procedure SetSize64(const NewSize: Int64);
  protected
    FRefCount: Integer;
    function QueryInterface(const IID: TGUID; out Obj): HResult; stdcall;
    function _AddRef: Integer; stdcall;
    function _Release: Integer; stdcall;
  public
    procedure AfterConstruction; override;
    procedure BeforeDestruction; override;
    class function NewInstance: TObject; override;
    property RefCount: Integer read FRefCount;

    procedure LoadFromStream(Stream: IDelphiStream); overload;
    procedure SaveToStream(Stream: IDelphiStream); overload;
    procedure LoadFromFile(const FileName: WideString); overload;
    procedure SaveToFile(const FileName: WideString); overload;
  end;

function TInterfacedMemoryStream.GetPosition: Int64;
begin
  Result := inherited Position;
end;

procedure TInterfacedMemoryStream.SetPosition(const Pos: Int64);
begin
  inherited Position := Pos;
end;

procedure TInterfacedMemoryStream.SetSize64(const NewSize: Int64);
begin
  inherited Size := NewSize;
end;

function TInterfacedMemoryStream.QueryInterface(const IID: TGUID; out Obj): HResult;
begin
  if GetInterface(IID, Obj) then
    Result := 0
  else
    Result := E_NOINTERFACE;
end;

function TInterfacedMemoryStream._AddRef: Integer;
begin
  Result := InterlockedIncrement(FRefCount);
end;

function TInterfacedMemoryStream._Release: Integer;
begin
  Result := InterlockedDecrement(FRefCount);
  if Result = 0 then
    Destroy;
end;

procedure TInterfacedMemoryStream.AfterConstruction;
begin
  InterlockedDecrement(FRefCount);
end;

procedure TInterfacedMemoryStream.BeforeDestruction;
begin
  if RefCount <> 0 then
    System.Error(reInvalidPtr);
end;

class function TInterfacedMemoryStream.NewInstance: TObject;
begin
  Result := inherited NewInstance;
  TInterfacedMemoryStream(Result).FRefCount := 1;
end;

procedure TInterfacedMemoryStream.LoadFromStream(Stream: IDelphiStream);
var
  buf: array[0..65535] of Byte;
  i: Integer;
begin
  Clear;
  while true do
  begin
    i := Stream.Read(buf, Length(buf));
    if i = 0 then break;
    if Write(buf, i) <> i then System.Error(reOutOfMemory);
  end;
end;

procedure TInterfacedMemoryStream.SaveToStream(Stream: IDelphiStream);
var
  buf: array[0..65535] of Byte;
  i: Integer;
begin
  Stream.Clear;
  while true do
  begin
    i := Read(buf, Length(buf));
    if i = 0 then break;
    if Stream.Write(buf, i) <> i then System.Error(reOutOfMemory);
  end;
end;

procedure TInterfacedMemoryStream.LoadFromFile(const FileName: WideString);
begin
  inherited LoadFromFile(String(FileName));
end;

procedure TInterfacedMemoryStream.SaveToFile(const FileName: WideString);
begin
  inherited SaveToFile(String(FileName));
end;

LoadFromStream und SaveToStream arbeiten hier intern aber nur mit String, also bis Delphi 2007 mit AnsiString.
Wenn man auch da wirklich den WideString unterstüzen will, dann muß man sich einen Unicode-fähigen FileStream besorgen (also Unicode bei den Dateinamen).

Und direkt AnsiString/UnicodeString geht halt wegen der getrennten Speicherverwaltung nicht so einfach ... stickwort SharedMemoryManager