如何提高jQuery的性能

Question

i have an chat application written in jsp and jQuery. I have used the setTimeout method for threads who are continuously posting request in some URL. My browser is hanging after some time and cpu utilization is very high.

Is there any way to increase performance of JS?

Answer 1

Check this one: http://www.tvidesign.co.uk/blog/improve-your-jquery-25-excellent-tips.aspx#tip1

It has some really good recommendations like:

• Keep selection operations to a minimum by caching
• Keep DOM manipulation to a minimum
• Use IDs instead of classes wherever possible
• Give your selectors a context

Answer 2

Have you tried debugging with Firebug ? You can use it to debug javascript, monitor requests and responses, and more.

Answer 3

Well i run trough this before here is what i did (by the way this has nothing to do with jquery) :

try {
    window.clearInterval(x);
} catch(e) {
    // do nothing
}
x = setInterval(Update, 1000);

in your case you should clearTimeout :)

try this :

refresh() { $.post("./chatServlet",  {  message: "hxci",  name: $("#author").val(),  event: "AUTOROOMMESSAGE",   roomname: $("#select").val() },   function(xml)   {   $("#msg").empty();   addMessages(xml);    });    try {    window.clearInterval(x);}    catch(e) {       }     x = setInterval(refresh, 3000);   }