Large main form loads SLOW

[vbdavie]

I have this mainform with tons of tabs and controls and labels etc... It was taking about 17 seconds before i saw the page start to display on the screen.

It worked fine, but the users were clicking refresh because they didn't think it was loading. They were impatient. So, i added a splash screen that displays almost immediately, but still about 17 seconds until the mainform displays.

I tracked it down to the uniGUIApplication.pas   JSPreProcess function. It consists of removing the /* and */ comments and then it removes the #3 and #4 characters.

The first task was taking about 4 seconds and the second task was taking about 13 seconds.

You can see that i modified the 1st task so that it takes less than a second instead of 4 seconds.
 

function TUniGUISession.JSPreProcess(const JSCode: string): string;
var
  I,J : Integer;
// the following variables are added by DLR
  PCharS:PChar;
  PCharD:PChar;
  Delta:Integer;
  DeltaTmp:Integer;
  OrigLen:Integer;
  ResultAddr:PChar;
  LastByte:PChar;
begin
// DLR FASTER COMMENT REMOVAL
  Result := JSCode;
  ResultAddr:=@Result[1];
  OrigLen:=Length(Result);
  LastByte:=PChar(Integer(@ResultAddr^)+OrigLen*SizeOf(Char));
  Delta:=0;
  I := pos('/*', Result);
  while I <> 0 do
  begin // Extracts comments
    J := PosEx('*/', Result, I);
    if J>I then
      Begin
      //DLE
      PCharS:=ResultAddr;
      Inc(PCharS,I + (J - I + 2)-1);
      PCharD:=ResultAddr;
      Inc(PCharD,I-1);
      DeltaTmp:=((J+1) - (I) + 1);
      Delta:=Delta + DeltaTmp;
// the move could be a little more efficient by not MOVING all the data, but it works fast
      Move(PCharS^,PCharD^,Integer(@LastByte^)-Integer(@PCharS^));
      End
    else
      Inc(I, 2);
    I := PosEx('/*', Result, I);
    If I>OrigLen-Delta Then I:=0;
  end;
//DLR
    SetLength(Result,OrigLen-Delta);

  Result := HandleJSReturns(Result);

  Result := AnsiReplaceStr(AnsiReplaceStr(Result, CommandDelim, ''), IdentDelim, ''); // Extracts aux delimiters
end;

You can see i use the MOVE instead of the DELETE operation. SO much more faster.

THEN the 2nd task was calling the "AnsiReplaceStr" function which is terribly SLOW and was taking about 13 seconds

So, I replaced that function with a replacement i found on the internet. So, i added this code BEFORE the "AnsiReplaceStr" usage.

 

function AnsiReplaceStr(const AText, AFromText, AToText: string): string;
begin
//DLR
  Result:= StrUtilsEx.FastStringReplace(AText, AFromText, AToText, [rfReplaceAll]);
//  Result:= SysUtils.StringReplace(AText, AFromText, AToText, [rfReplaceAll]);
end;
Function StringReplace(const S, OldPattern, NewPattern: string;  Flags: TReplaceFlags): string;
Begin
//DLR
Result:= StrUtilsEx.FastStringReplace(S, OldPattern, NewPattern, [rfReplaceAll]);
//Result:= SysUtils.StringReplace(S, OldPattern, NewPattern, [rfReplaceAll]);
End;

Of course you will have to include StrUtilsEx in your USES clause.

You can see that my replacement functions call a different function in the StrUtilsEX.PAS module. It's much faster. Probably 15 times faster.

So, now the 2nd task takes less than 1 second instead of the 13 seconds.

The end result is that my splash screen is only displayed for about 4 seconds instead of 17. Great improvement.

Keep in mind that this fix is EXTREMELY useful only for LARGE FORMS with tons of controls. You won't notice any difference on small forms.

Now for the magic, I have attached the StrUtilsEX.PAS file for your pleasure.

Have fun with faster loading forms.

If UNIGUI would implement my changes or similar that would be great, OTHERWISE I/we have to update the UniGUIApplication.pas file each time we download a new version

Davie

 

StrUtilsEx.pas

[Sherzod]

Hello,

We will try to analyze.

Thank you.