304753 - [FIX]nsImageMap is too eager to invalidate on attribute changes

Status: RESOLVED FIXED

(Core :: Layout, defect, P2)

Description

[Boris Zbarsky [:bzbarsky]]

STEPS TO REPRODUCE:

1)  Load https://bugzilla.mozilla.org/attachment.cgi?id=162706
2)  Watch it freeze up for 2-3 seconds

EXPECTED RESULTS: no freeze

The problem is that we rebuild the imagemap on every attr set, which makes the
whole thing O(N^2) in the number of <area>s.  Since none of the attrs relevant
to the functioning of the imagemap are changing, we shouldn't be rebuilding.

Comment 1

[Boris Zbarsky [:bzbarsky]]

Attachment: Proposed patch

Comment 2

[Johnny Stenback (:jst)]

Comment on attachment 192780 [details] [diff] [review]
Proposed patch

+  if (aContent->IsContentOfType(nsIContent::eHTML) &&
+      (aContent->GetNodeInfo()->Equals(nsHTMLAtoms::area) ||
+	aContent->GetNodeInfo()->Equals(nsHTMLAtoms::a)) &&

aContent->GetNodeInfo() is a virtual function, you may be better off storing it
in a local here. Your call.

r+sr=jst either way.

Comment 3

[Boris Zbarsky [:bzbarsky]]

This is 1.9 stuff, and I expect peterv's inlining (and renaming) of
nsIContent::NodeInfo() to land in 1.9, hopefully sometime soon.  ;)

Comment 4

[Peter Van der Beken [:peterv]]

(In reply to comment #3)
> peterv's inlining (and renaming) of
> nsIContent::NodeInfo()

That's sicking's, I wouldn't do such crazy things! :-P

Comment 5

[Boris Zbarsky [:bzbarsky]]

Fixed.