Analyse jQuery selector performance?

Is there an analytics tool of any kind to analyse the performance of selectors on a site (ie. number of iterations over the dom, average time taken for each search, number of searches etc.)? Either a desktop tool, or a jQuery plugin or anything?

We are finding performance开发者_StackOverflow社区 is being impacted by the number of selector searches jQuery is doing.

When I search this topic in Google I found it hard to get past all the results for using Google Analytics in jQuery (This is not what I want!)

John Resig himself has a plugin which analyses jQuery performance on a site.

http://ejohn.org/blog/deep-profiling-jquery-apps/

I will check it out and see how it goes!

Edit: This is still essentially at a page level too. I am really looking for something that is at a site level...

Haven't tried it but the "DOM Monster" bookmarklet looks helpful. You get it if you buy the JavaScript Performance Rocks eBook (see http://jsrocks.com)

I am going to add a couple of hooks to the selector code in jQuery myself, which will write to cookies that store analytics data to analyse the performance across a site.

This functionality does not appear to be easily available at this point.