Bug 77745 – Shareable stylesheet data structures

• Status: NEW
• Component: CSS

[Antti Koivisto]

To improve performance and save memory we should make stylesheet data structures cacheable in the memory cache and shareable between documents.

[Antti Koivisto]

<rdar://problem/10217321>

[Antti Koivisto]

Related bunch of recent bugs towards this goal.

[Eric Seidel (no email)]

Interesting.  I'm attempting to "share" stylesheets between documents for <iframe seamless>:
https://github.com/eseidel/webkit/compare/master...seamless#L61R423

I wonder if I'm getting myself in trouble. :)

[Antti Koivisto]

(In reply to comment #3)
> Interesting.  I'm attempting to "share" stylesheets between documents for <iframe seamless>:
> https://github.com/eseidel/webkit/compare/master...seamless#L61R423
> 
> I wonder if I'm getting myself in trouble. :)

That is going to be bit tricky. Stylesheets can mutate, the style selectors in the sharing child frames will need to be reset too. They hold raw pointers so this must happen synchronously.

Should still be doable.

[Eric Seidel (no email)]

(In reply to comment #4)
> (In reply to comment #3)
> > Interesting.  I'm attempting to "share" stylesheets between documents for <iframe seamless>:
> > https://github.com/eseidel/webkit/compare/master...seamless#L61R423
> > 
> > I wonder if I'm getting myself in trouble. :)
> 
> That is going to be bit tricky. Stylesheets can mutate, the style selectors in the sharing child frames will need to be reset too. They hold raw pointers so this must happen synchronously.
> 
> Should still be doable.

Yes, I need to find wherver the CSSStyleSelector is reset on the parent(s) and make sure all seamless iframe documents also recalc their selectors at that time.  If you have suggestions for specific methods I should hack into, I'm all ears (we can also discuss this on a different bug).