DataSnap的大流

Question

我试图在DataSnap服务器/客户端之间传输一些大流(~1Mb),但无济于事.我试图理解吉姆蒂尔尼的代码(http://blogs.embarcadero.com/jimtierney/2009/04/06/31461)没有运气,我甚至无法编译代码,因为缺少库,无论如何......

我能够接收的流的最大大小是64k,因此您可以为像我这样的周末程序员提供的任何提示/想法/代码示例都会受到欢迎.谢谢!

我的服务器代码:

function TsrvMethods.getStream(iCount: integer): TStream;
begin
  Result := dummyStream('0123456789', iCount);
end;

function dummyStream(sCnt: string; iCount: integer): TStream;
begin
  Result := TMemoryStream.Create;
  while iCount > 1 do begin
    Result.Write(Pointer(sCnt)^, Length(sCnt));
    Dec(iCount);
  end;
  Result.Seek(0, TSeekOrigin.soBeginning);
end;

我的客户端调用代码:

procedure TfrmMain.butStreamClick(Sender: TObject);
var
  sStr : TStream;
begin
  cycleConnection; //make sure we have an active connection

  with TsrvMethodsClient.Create( SQLConn.DBXConnection, False ) do begin
    sStr := getStream( Integer(SpinCount.Value) );
    Free;
  end;
  FreeAndNil(sStr);
end;

Answer 1

实际上,我想我已经明白了.我发布这个作为答案,也许其他人需要这个.

procedure TfrmMain.butStreamClick(Sender: TObject);
const
  iBufSize = 128;
var
  sStr : TStream;
  sMem : TMemoryStream;
  buf: PByte;
  iRead: integer;
begin
  cycleConnection;

  with TsrvMethodsClient.Create( SQLConn.DBXConnection, False ) do begin

    sStr := getStream( 500000 ); //500k stream

    GetMem(buf, iBufSize);
    sMem := TMemoryStream.Create;
    try
      repeat
        iRead := sStr.Read( Pointer(buf)^, iBufSize);

        if iRead > 0 then sMem.WriteBuffer( Pointer(buf)^, iRead);
        if iRead < iBufSize then break;
      until iRead < iBufSize;
    finally
      FreeMem(buf, iBufSize);
    end;

    Free;
  end;
  FreeAndNil(sStr);
  FreeAndNil(sMem);
end;

PS

通过搜索DataSnap代码示例,我发现一个(速度相关的)改进是将iBufSize设置为61440(或等效的十六进制值$ F000),这似乎是可以一次性接收的最大尺寸.如果接收流较大,则报告的大小将为-1,并且需要上面的代码来读取整个流.