395058 - getAnonymousElementByAttribute is slowing Ts / Txul

Status: NEW

(Core :: DOM: Core & HTML, defect, P5)

Description

[Robert Sayre]

This function is a major hotspot for the JS that executes in chrome on startup.

I'm not sure whether this is due to overall tabbrowser.xml complexity, or there's something inherently slow about it. Is there a reason we can't use other methods of selecting these elements?

Comment 1

[Robert Sayre]

Attachment: function times on trunk

Comment 2

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

Do you have any data on what attribute names are searched? If it's a lot of 'id', it'd probably help to atomize the value before searching in the implementation.

Comment 3

[Robert Sayre]

So, I think I see why we're detecting slow calls here, but Stuart's profiles don't show it. They're nesting:

61811        tabbrowser.xml           | -> getAnonymousElementByAttribute
4257760      tabbrowser.xml           |  -> getAnonymousElementByAttribute
5228638      scrollbox.xml            |   -> getAnonymousElementByAttribute

Timeless tells me this is because of XBL lazy binding.

Comment 4

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

So what I think we should do here is to make "anonid" always stored as an atom, and then make getAnonymousElementByAttribute use atom-values when doing the searching. Not sure that it'll make a big difference, but it might help a bit.

Comment 5

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1472046

Move all DOM bugs that haven’t been updated in more than 3 years and has no one currently assigned to P5.

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