program readfile;

{$mode objfpc}{$H+}

uses
  {$IFDEF UNIX}{$IFDEF UseCThreads}
  cthreads,
  {$ENDIF}{$ENDIF}
  Classes, SysUtils, CustApp,
  windows
  { you can add units after this };

type

  { readfile }

  rfile = class(TCustomApplication)
  protected
    procedure DoRun; override;
  public
    constructor Create(TheOwner: TComponent); override;
    destructor Destroy; override;
    procedure WriteHelp; virtual;
  end;

{ rfile }




procedure rfile.DoRun;
var
  ErrorMsg, FileName: String;
  //Fin : File;
  Fin : THANDLE;
  NumRead, PrevNumRead, NumOverlapped : LongWord;
  Buf : Array of Byte;
  BufSize, NumReadOps, StartTime, EndTime, ExecTime, Size:  Int64;
  Speed : Double;
  fsizehigh, fsizelow: DWORD;
begin
  // quick check parameters
  ErrorMsg:=CheckOptions('h','help');
  if ErrorMsg<>'' then begin
    ShowException(Exception.Create(ErrorMsg));
    Terminate;
    Exit;
  end;

  // parse parameters
  if HasOption('h','help') then begin
    WriteHelp;
    Terminate;
    Exit;
  end;

  If Paramcount < 1 then WriteHelp;
  FileName := ParamStr(1);

  If ParamCount > 1 then
    BufSize := StrToInt(ParamStr(2))
  else
    BufSize := 4096;

  NumRead  := 0;
  SetLength(Buf, BufSize);
  Bufsize  := Length(Buf);
  NumReadOps:=0; // Number of read operations

  If FileExists (FileName) then
    begin
      //System.Assign (Fin, FileName);
//Fin := windows.CreateFile(PChar(FileName),FILE_FLAG_NO_BUFFERING, 0, LPSECURITY_ATTRIBUTES,OPEN_EXISTING, 0, 0);
      Fin := CreateFile(
          PChar(FileName),
          GENERIC_READ,
          0,
          NIL,
          OPEN_EXISTING,
          FILE_FLAG_NO_BUFFERING,
          0);

      if (Fin = INVALID_HANDLE_VALUE) then
    Exit;
      fsizelow := Windows.GetFileSize(Fin, Pointer(@fsizehigh));

      //Reset (Fin,1);
      WriteLn('Reading "',FileName,'"');
      //WriteLn('FileSize: ',FileSize(Fin), ' bytes');
      WriteLn('FileSizeHigh: ',fsizehigh, ' bytes');
      WriteLn('FileSizeLow: ',fsizelow, ' bytes');
      WriteLn('Bufsize:', bufsize);

      StartTime := Windows.GetTickCount();
      Repeat
        PrevNumRead := NumRead;
        //BlockRead (Fin,buf[0],BufSize,NumRead);
        Windows.ReadFile(Fin, Buf[0], BufSize, NumRead, @NumOverlapped);
        inc(NumReadOps);
        //If NumReadOps mod 100000 = 0 then
        //  writeln(Total, ' : ', NumReadOps * BufSize);
      Until (NumRead=0);
      //close(Fin);
      Windows.CloseHandle(Fin);
      EndTime := Windows.GetTickCount();
      // Add 1 in order to avoid divbyzero on very short exectime
      ExecTime:= EndTime - StartTime + 1;

      WriteLn();
      //WriteLn('Numread=',NumRead);
      //WriteLn('PrevNumRead=',PrevNumRead);
      //writeln(NumReadOps, ' : ', NumReadOps * BufSize);

      Size  := (NumReadOps-2) * BufSize + PrevNumRead;
      If Size < 0 then Size := 0;
      Speed := Size / ExecTime;
      WriteLn ('Read ',Size,
              ' bytes (', FloatToStrF(Size/1024/1024, ffFixed,1,1),
              ' mb) from file ',FileName,
              ' in ', ExecTime, ' ms :');
      Speed := Size / (ExecTime/1000);
      WriteLn(FloatToStrF(speed,ffFixed,1,2),                  ' b/s');
      WriteLn(FloatToStrF(speed/1024,ffFixed,1,2),            ' kb/s');
      WriteLn(FloatToStrF(speed/1024/1024,ffFixed,1,2),       ' mb/s');
      WriteLn(FloatToStrF(speed/1024/1024/1024,ffFixed,1,2),  ' gb/s');
    end
  else
  begin
    Writeln ('File "'+FileName+'" NOT found');
  end;
  //Write('Enter to quit');
  //ReadLn;

  // stop program loop
  Terminate;
end;

constructor rfile.Create(TheOwner: TComponent);
begin
  inherited Create(TheOwner);
  StopOnException:=True;
end;

destructor rfile.Destroy;
begin
  inherited Destroy;
end;

procedure rfile.WriteHelp;
begin
  WriteLn('Usage: '+ExeName+' <filename> [bufsize]');
  WriteLn('       Default bufsize: 4096');
  WriteLn('');
  WriteLn('Example: ', ExeName, ' c:\tempfile.dat 1024');
  Halt;
end;


var
  Application: rfile;

{$R *.res}


begin
  Application:=rfile.Create(nil);
  Application.Title:='rfile';
  Application.Run;
  Application.Free;
end.