[Webkit-unassigned] [Bug 33696] let's cache nodelists instead of dynamicnodelist::cache

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=33696





--- Comment #24 from anton muhin <antonm at chromium.org>  2010-01-22 05:12:54 PST ---
(In reply to comment #23)
> (In reply to comment #22)
> > (In reply to comment #21)
> > > Mozilla has been returning the same NodeList from getElementsByTagName for a
> > > long time:
> > > https://bugzilla.mozilla.org/show_bug.cgi?id=140758
> > > 
> > > It's not clear if they know this technically violates the DOM Core spec, but it
> > > does seem to imply the behavior is safe for Web compatibility.
> > 
> > Yep, I verified that Mozilla caches node lists as well.
> > 
> > And regarding standard.  There is funny inconsistency. If you take a look at
> > Document wording it says new, but for Element wording it doesn't say new for
> > getElementsByTagName, but does for getElementsByTagNameNS.
> > 
> > Answering another question: gain is due to reduced pressure on GC, so producing
> > new JS wrappers would most probably kill the optimization.  And Mozilla bug you
> > spotted says roughly the same.
> > 
> > So the conclusion is we are waiting for changed HTML5 spec?
> > 
> > If yes, any ETA?
> > 
> > And thanks a lot for very interesting investigation of the question.
> 
> I think we should suggest a change or erratum to the DOM Level 3 Core spec. It
> seems like even if returning a new object was intended, it's not what
> implementations do. I suggest mailing public-webapps at w3.org to start a
> discussion. Or I can do it if you'd rather not deal with the standards groups.

Mac(In reply to comment #23)
> (In reply to comment #22)
> > (In reply to comment #21)
> > > Mozilla has been returning the same NodeList from getElementsByTagName for a
> > > long time:
> > > https://bugzilla.mozilla.org/show_bug.cgi?id=140758
> > > 
> > > It's not clear if they know this technically violates the DOM Core spec, but it
> > > does seem to imply the behavior is safe for Web compatibility.
> > 
> > Yep, I verified that Mozilla caches node lists as well.
> > 
> > And regarding standard.  There is funny inconsistency. If you take a look at
> > Document wording it says new, but for Element wording it doesn't say new for
> > getElementsByTagName, but does for getElementsByTagNameNS.
> > 
> > Answering another question: gain is due to reduced pressure on GC, so producing
> > new JS wrappers would most probably kill the optimization.  And Mozilla bug you
> > spotted says roughly the same.
> > 
> > So the conclusion is we are waiting for changed HTML5 spec?
> > 
> > If yes, any ETA?
> > 
> > And thanks a lot for very interesting investigation of the question.
> 
> I think we should suggest a change or erratum to the DOM Level 3 Core spec. It
> seems like even if returning a new object was intended, it's not what
> implementations do. I suggest mailing public-webapps at w3.org to start a
> discussion. Or I can do it if you'd rather not deal with the standards groups.

I see, thanks, Maciej.  I've sent an email cc'ing you.  If anyone else wants to
be in the loop, just let me know.

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