Selector performance regression when parsing XML

Reported by:	steveworkman	Owned by:	steveworkman
Priority:	undecided	Milestone:	None
Component:	unfiled	Version:	1.7
Keywords:		Cc:
Blocked by:		Blocking:

Description

Related to http://bugs.jquery.com/ticket/10377 jQuery 1.7 no longer supports selecting XML nodes by [nodeName='z:row']. The agreed workaround is to use "z\\\\:row, row" as the selector instead.

Running this through larger amounts of data, I'm seeing significant slow-down in IE browsers when using 1.7 compared to using 1.6.4. JSPerf test can be seen here http://jsperf.com/node-vs-double-select

Performance appears to have reduced by half in IE8, Opera 12 and Safari 5.1 and by small amounts in other browsers. Chrome and Firefox performance is almost identical.

Attachments (0)

Change History (5)

Changed November 08, 2011 02:38PM UTC by dmethvin comment:1

owner:	→ steveworkman
status:	new → pending

Did you try the custom plugin in the ticket? If you're having performance issues that should be much faster.

Changed November 08, 2011 04:05PM UTC by steveworkman comment:2

status:	pending → new

Replying to [comment:1 dmethvin]:

Did you try the custom plugin in the ticket? If you're having performance issues that should be much faster.

I've updated the perf test http://jsperf.com/node-vs-double-select with a custom filter-based plugin. It works and is a lot faster, but in order to select the right set in the first place I have to go 8 levels of children() down because filter does not recurse like find does. It is much faster, but:

1. doesn't solve the performance problem in 1.7

2. isn't work-able because I'm having to use multiple .children() calls

Changed November 08, 2011 05:26PM UTC by dmethvin comment:3

status:	new → pending

If you're going that deep, use a filter function passed to .find(). How does that fare?

Changed November 09, 2011 01:53PM UTC by steveworkman comment:4

status:	pending → new

Replying to [comment:3 dmethvin]:

If you're going that deep, use a filter function passed to .find(). How does that fare?

Testing the following function:

$.fn.filterNode = function(name) {
      return this.find('*').filter(function() {
        return this.nodeName === name;
      });
    };

I get a very fast selector, in the order of 200x faster than

.find('z\\\\:row, row')

and about 5x faster than the

.children().children().children().children().children().children().children().filterNode('z:row')

function.

Full jsPerf test results are at http://jsperf.com/node-vs-double-select/3

Could this one-line plugin be integrated into the selector engine to allow for faster node selection?

Changed November 09, 2011 01:56PM UTC by dmethvin comment:5

resolution:	→ worksforme
status:	new → closed

That's not a very generalized function, so no. Filtering with a function *is* generalized and it does exactly what you want in this case.

Side navigation

#10720 closed bug (worksforme)