[webkit-qt] webkit2, v8, diplomacy

Keith Kyzivat keith.kyzivat at nokia.com
Tue Jun 5 07:35:02 PDT 2012


On 06/05/2012 09:22 AM, ext Balazs Kelemen wrote:
> On 06/05/2012 03:12 PM, Coda Highland wrote:
>> I don't understand why the push for V8 in the first place. JSC and V8
>> are in an arms race for performance, so you can't categorically say V8
>> is faster because that's not always true.
>
> I did not say it's faster or superior but using two js engines in a 
> stack is insane.
>
>> JSC also has broader support
>> (see Konstantin's post). Furthermore, my understanding is that V8
>> doesn't expose the necessary APIs to be able to provide the full scope
>> of the QtScript API. (Has this changed since the original plans to
>> move to V8 were announced?)
>
> I don't think v8 lack's any API that JSC has. If we only consider 
> public API, I think v8 is much more rich - maybe I'm wrong. Anyway, 
> declarative - which is really a fundamental of Qt5 - is using v8 and I 
> guess there is a reason for that and it's not desirable to move it to 
> JSC.

I have been hearing speak of Qt trying something new/moving away from 
using v8 (I think because v8 is not optimized for the quick entry/exit 
that QML does), though I imagine that Qt5 will stil provide opportunity 
to use v8...

Isn't there a way we can have v8 and JSC be separate options, with one 
or the other compiled in at compile-time?
How about separating out the JS engine entirely into a separate shared 
library?
Granted, there's a maintenance cost for maintaining both engines...  
Maybe you're considering that in addition to the memory savings you 
mentioned?

~Keith
-- 
Keith "Keithel" Kyzivat     | mailto: keith.kyzivat at nokia.com
Senior SW Engineer, Browser | callto: +1 (978) 821-7115
Nokia, MP Development       | sendto: 5 Wayside Rd.
                             | Burlington, MA 01803 USA



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