Thanks. If only I could use something this simple for my graduation
thesis :D
That was mr. Firefox 3.0.5 on a C2D 1.6ghz. Firebug's timing is said
not to be reliable, but I don't think there's much distortion in that.
For a comparison, simply looping over the creation of 5000 functions
takes mere 5ms.
happy new year to all!
On Dec 31 2008, 3:42 am, "Michael Geary" <m...@mg.to> wrote:
> Excellent analysis, Ricardo. BTW, which browser did you run your timing test
> in?
>
> Here's another tip. If you really do need to have thousands of ready
> functions, you can speed things up a bit by rolling your own. For example:
>
> window.ready = [];
> jQuery(function() {
> for( var fn, i = -1; fn = ready[++i]; )
> fn( jQuery );
> });
>
> Now you can replace each instance of:
>
> $(function() { ... });
>
> With:
>
> ready.push( function() { ... } );
>
> Or, for a bit more of a speedup in IE:
>
> ready[ready.length] = function() { ... };
>
> -Mike
>
> > From: Ricardo Tomasi
>
> > Hi Kean,
>
> > AFAIK, ready() puts the function you passed into an array of
> > functions. Another function is bound to the DOMContentLoaded
> > event, which is fired when the DOM is ready on compliant
> > browsers. For the others, several methods are in place to
> > detect when DOM is loaded.
> > When the event fires/DOM load is detected, that function
> > starts calling each of the functions in that array.
>
> > Was I clear? :D
>
> > In short, ready() stacks functions that will get executed
> > when DOMContentLoaded fires or the other browser techniques
> > detect DOM is complete. The slowness in this comes mostly
> > from the overhead of jQuery's methods. When you call $()
> > jQuery has to:
> > 1. check if you're passing an object/function/array/selector
> > string 2. grab the 'document' object (default) 3. return the
> > jQuery object with document 4. call the ready() method on
> > that object passing your function 5. store the function in an array
>
> > that's quite a bit of overhead. this:
>
> > (function(){
> > console.time('a');
> > for (var i=-1;i<5000;i++){
> > $(function(){});
> > }
> > console.timeEnd('a');
> > })();
>
> > takes around 200 ms here.
>
> > $(document).ready() is a bit faster, around 90ms, probably
> > because it doesn't run as many conditionals to guess what you want.
>
> > hope that was helpful!
>
> > cheers,
> > -ricardo
>
> > cheers,
> > - ricardo
>
> > On Dec 31, 1:49 am, Kean <shenan...@gmail.com> wrote:
> > > No, I don't take that as an insult.
>
> > > I was just wondering how document ready was coded so it really was
> > > just a hypothetical question.
>
> > > Why do I really need so much on ready?
>
> > > Also, MorningZ, I will be very active in the jQuery mailing list in
> > > future to learn more js. Perhaps this is not the best
> > starting point
> > > for us.
>
> > > On Dec 30, 7:23 pm, MorningZ <morni...@gmail.com> wrote:
>
> > > > "There probably is a better way to do it. "
>
> > > > Which is what i was getting at...... i hope "honest"
> > isn't/wasn't
> > > > taken as "insulting"
>
> > > > On Dec 30, 10:16 pm, "Michael Geary" <m...@mg.to> wrote:
>
> > > > > Come on, MorningZ, there's no need for insults.
>
> > > > > But yes, 5000 of those will be pretty slow - and that's
> > before you
> > > > > even execute the code inside those functions. How slow?
> > It's easy
> > > > > to test. The ready functions are run in the order that the $()
> > > > > functions are called. So simply do this in a test page:
>
> > > > > var t1 = +new Date;
> > > > > $(function(){});
> > > > > // ... Repeat above line 5000 times
> > > > > $(function() {
> > > > > var t2 = +new Date;
> > > > > alert( (t2-t1)/1000 + ' seconds' );
> > > > > });
>
> > > > > You can easily generate that file by hand in a text editor. You
> > > > > don't have to do 5000 pastes. Start with 10 of them, copy that
> > > > > block and paste it 10 times so you have 100, copy
> > *that* block and
> > > > > paste it 10 times so you have 1000, copy that and five
> > more pastes and you're done.
>
> > > > > Test it in IE6 (!), and if you're on your usual development
> > > > > machine, triple the time from the alert to take into
> > account the
> > > > > slower machines that your visitors will have (think a
> > slow laptop
> > > > > running on battery). If you don't have IE6, try it in
> > IE7 and as a
> > > > > rough guess, multiply your observed time by six (triple
> > for the slow machines, double again for IE6).
>
> > > > > Mind if I ask: why do you need 5000 of these? There
> > probably is a
> > > > > better way to do it.
>
> > > > > -Mike
>
> > > > > > From: MorningZ
>
> > > > > > If you've got 5000 of those, it's *seriously* time to
> > reconsider
> > > > > > your coding techniques..... depending on that much
> > JavaScript
> > > > > > is just plain old stupid......
> > > > > > On Dec 30, 8:59 pm, Kean <shenan...@gmail.com> wrote:
> > > > > > > Is document ready "actually" an event handler?
>
> > > > > > > Let's say I have
>
> > > > > > > $(function(){
>
> > > > > > > });
>
> > > > > > > $(function(){
>
> > > > > > > });
>
> > > > > > > $(function(){
>
> > > > > > > });
>
> > > > > > > $(function(){
>
> > > > > > > });
>
> > > > > > > $(function(){
>
> > > > > > > });
>
> > > > > > > etc ..... around 5000 of those.
>
> > > > > > > Will it actually degrade performance like 5000 bind()?
> > > > > > > My guess is not much performance penalty, but
> > again, it's a guess.
