RtlVclOptimize 2.77 - DelphiSpeedUp Code im eigenen Programm

[bigg]

Zitat von jgb:

Wenn du dein System ausbremsen willst, kannst du das ja gerne machen.

Jein.
Der Leistungsgewinn von etwa 100% überzeugen mich dann doch.
Wobei deine Funktion im WorstCase (pagefile.sys) recht bescheiden weg kommt. *hüstel*

Delphi-Quellcode:

function RTL_MOD_FileExists(const FileName: String): Boolean;
var
  Handle: THandle;
  FindData: TWin32FindData;
begin
  Result := False;
  Handle := Windows.FindFirstFile(PChar(FileName), FindData);

  if Handle <> INVALID_HANDLE_VALUE then
  begin
    Result := ( (FindData.dwFileAttributes and FILE_ATTRIBUTE_DIRECTORY) = 0 );
    Windows.FindClose(Handle);
  end;
end;


function jgbFileExists(const Filename: string): Boolean;

  function FailSafe(const Filename: string): Boolean;
  var
    FindData: TWin32FindData;
    h: THandle;
  begin
    { Either the file is locked/share_exclusive or we got an access denied }
    h := Windows.FindFirstFile(PChar(Filename), FindData);
    if h <> 0 then
    begin
      Windows.FindClose(h);
      Result := FindData.dwFileAttributes and FILE_ATTRIBUTE_DIRECTORY = 0;
    end
    else
      Result := False;
  end;

var
  Code: Integer;
  LastError: Cardinal;
begin
  Code := Integer(Windows.GetFileAttributes(Pointer(FileName)));
  if Code <> -1 then
    Result := (FILE_ATTRIBUTE_DIRECTORY and Code = 0)
  else
  begin
    LastError := Windows.GetLastError();
    Result := (LastError <> ERROR_FILE_NOT_FOUND) and
              (LastError <> ERROR_PATH_NOT_FOUND) and
              FailSafe(Filename);
  end;
end;



procedure TForm1.Button1Click(Sender: TObject);
var b: Boolean;
    i: Integer;
    Start: Cardinal;
    s, FileName: String;
begin
  i := 0;
  Start := Windows.GetTickCount;
  //FileName := 'C:\pagefile.sys';
  FileName := 'C:\boot.ini';

  repeat
    //b := jgbFileExists(FileName);
    b := MyFileExists(FileName);
    inc(i);
  until (i > 100000);

  if b then
    s := 'True'
  else
    s := 'False';

  ShowMessage( IntToStr(Windows.GetTickCount - Start) + ' ms' + #13#10 + s);
end;

Gruß