Desaströse Performance von TRichedit

[Uwe Raabe]

Zitat von Maekkelrajter:

Festzustehen scheint, dass die aktuelle Implementierung von TRichedit gewissermaßen suboptimal ist.

Ich habe das mal auf einen simplen WinApi-Aufruf reduziert und komme auf ziemlich dieselben Werte. Es hängt also wohl nicht an der Delphi-Implementierung.

Delphi-Quellcode:

  var FN:= 'c:\Users\Uwe\Downloads\TestDateien\Windows_ITunesContent.txt';
//  var FN:= 'c:\Users\Uwe\Downloads\TestDateien\MacOS_ItunesContent.txt';
  var S := TFile.ReadAllText(FN, TEncoding.Unicode);
  var sw := TStopwatch.StartNew;
  RichEdit1.SetSelText(S);
  label1.Caption := sw.ElapsedMilliseconds.ToString;

Warum die doppelt so große Windows-Datei aber nur 1/4 der Zeit braucht erschließt sich mir noch nicht so ganz.

[himitsu]

TextDateien ohne Formatierung ... warum überhaupt in ein RichEdit anstatt in ein Memo?

[Uwe Raabe]

Zitat von himitsu:

TextDateien ohne Formatierung ... warum überhaupt in ein RichEdit anstatt in ein Memo?

Na ja, weil:

Zitat von Maekkelrajter:

Aber einige optische Gimmicks wie mehrfarbiger Text sind eben mit einem TMemo nicht zu realisieren.

[himitsu]

Zitat von Uwe Raabe:

Zitat von himitsu:

TextDateien ohne Formatierung ... warum überhaupt in ein RichEdit anstatt in ein Memo?

Na ja, weil:

Zitat von Maekkelrajter:

Aber einige optische Gimmicks wie mehrfarbiger Text sind eben mit einem TMemo nicht zu realisieren.

ups.

SynEdit/SynMemo oder dergleichen?
oder das neue Direct2D-RichEdit ... müsste man doch bestimmt gut im FireMokey einbinden können.
(der Start von dem Geraffel dauert zwar ewig, aber danach scheint es schnell zu sein)

[Kas Ob.]

What about this

Delphi-Quellcode:

var
  Stream: TMemoryStream;
begin
  Stream := TMemoryStream.Create;
  try
    Stream.LoadFromFile(FILE_NAME);
    SendMessage(RichEdit1.Handle, WM_SETTEXT, LPARAM(0), WPARAM(Stream.Memory)); // better to add to the stream another byte with 0 or double bytes with 0, but for testing now
    //Stream.Position := 0;
    //RichEdit1.Lines.LoadFromStream(Stream);
  finally
    Stream.Free;
  end;
end;

[himitsu]

Zitat von Kas Ob.:

What about this

And this is supposed to work in a Delphi since 2009?

SendMessage = SendMessageW = Unicode
Is your file also Unicode?

[Kas Ob.]

Zitat von himitsu:

Zitat von Kas Ob.:

What about this

And this is supposed to work in a Delphi since 2009?

SendMessage = SendMessageW = Unicode
Is your file also Unicode?

It should !

Notice by sending the stream in full as it in the file, meaning the header included U+FEFF BOM header, yet the Window class recognized it, and handle it right, this even should work with Delphi 5.

But was it faster ?

[Uwe Raabe]

Zitat von himitsu:

Is your file also Unicode?

At least the example files posted above are.

Anyway, the TMemoryStream approach is quite similar to setting the Text or SelText with a string. It doesn't affect the performance, though.

[Kas Ob.]

Zitat von himitsu:

Zitat von Kas Ob.:

What about this

And this is supposed to work in a Delphi since 2009?

SendMessage = SendMessageW = Unicode
Is your file also Unicode?

Yes after re-reading more, i think WM_SETTEXT with Delphi 5 or may be even Delphi 7 might not work, as it will fail to handle the BOM marker for UTF16, as the used RichEdit class is version 1.0 and it is

Zitat:

ANSI (single-byte character set (SBCS) and multibyte character set (MBCS)) editing

So will work if the class changed to version 2.0, yet i might be wrong though, all in all this need more digging.

[Kas Ob.]

Well, if someone reading my writing somewhere, then try this

Delphi-Quellcode:

var
  Stream:TMemoryStream;
begin
  Stream := TMemoryStream.Create;
  try
    Stream.LoadFromFile(FILE_NAMEXX);
    Stream.Position := 0;
    RichEdit1.Lines.LoadFromStream(Stream);
  finally
    Stream.Free;
  end;
end;

The problem is known, which is the ****** stream handling in RTL, and also in VCL, it does many small read at 2kb (like it was bronze age) instead of 64kb, anyway TMemoryStream will load this stuff in full in memory and feed it, this should be faster, (Well in theory and in my slow brain)