Bug 164603 – Speed up HTMLInputElement validation

• Component: DOM
• Status: RESOLVED FIXED

[Chris Dumez]

Speed up HTMLInputElement validation.

[Chris Dumez]

Created attachment 294462 [details]
Patch

[Radar WebKit Bug Importer]

<rdar://problem/29213028>

[WebKit Commit Bot]

Comment on attachment 294462 [details]
Patch

Clearing flags on attachment: 294462

Committed r208577: <http://trac.webkit.org/changeset/208577>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Darin Adler]

Comment on attachment 294462 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=294462&action=review

> Source/WebCore/html/TextFieldInputType.cpp:397
> +    return newLength < string.length() ? string.left(newLength) : string;

What was the point of this change? Change log doesn’t seem to say. String::left should do this optimization, not the call site.

[Chris Dumez]

(In reply to comment #5)
> Comment on attachment 294462 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=294462&action=review
> 
> > Source/WebCore/html/TextFieldInputType.cpp:397
> > +    return newLength < string.length() ? string.left(newLength) : string;
> 
> What was the point of this change? Change log doesn’t seem to say.
> String::left should do this optimization, not the call site.

String::left currently does not do this optimization, neither does substring() which left() relies on. The reason I made this change is because I saw the input value sanitization spending time under String::substring (called from TextFieldInput::limitLength) even though the value length is never above the limit.

I am happy to move the optimization to left() or substring() though if you think it is better. I was trying to restrict the scope of my change to HTMLInputElement. It is kind of silly to call s.left(s.length()) which is why I felt it may be better to not do this and deal with it at the call site rather than add a branch in s.left() which may slow down "sane" call sites.