[webkit-dev] EventListener Invocation Cost?

Alex Milowski alex at milowski.org
Mon Jan 10 11:15:01 PST 2011

On Mon, Jan 10, 2011 at 10:19 AM, Darin Adler <darin at apple.com> wrote:
> On Jan 9, 2011, at 11:56 AM, Alex Milowski wrote:
>> I'm not sure there is a lot that can be done about it.
> I’m sure we can speed it up if we have a reason to. Step one is to find out exactly where the time is spent. Then we figure out ways to streamline the code path. The experts on this may not have the same priorities you do, so they may not have plans to spend time improving it.

I will certainly spend some time trying to narrow this down but I also
think my current situation is rather extreme and so I may have "spoke
too soon."  Digging deeper into the performance of the API I'm
experimenting with shows, by no surprise, that it delivers an extreme
number of small event objects.  There is always going to be a penalty
for that but the relative performance of the execution of the event
listener is actually rather good if you take the number of events
delivered into account.  I'm certain that a listener within C++ would
perform better, but that isn't a big surprise either.

When you take the overall application speed into account, things look
very different.  That is, not just the speed of parsing and delivering
the XML information but how long does it take the application to load
or use the data it has received.

--Alex Milowski
"The excellence of grammar as a guide is proportional to the paucity of the
inflexions, i.e. to the degree of analysis effected by the language

Bertrand Russell in a footnote of Principles of Mathematics

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