A TreeWalker ends up walking potentially every single subsequent
node in the document looking for a target node. Instead use upwards
traversal to find a common ancestor, then sibling traversal to
compare document order.
This makes calling cloneContents on every comment on a 300k talk page
significantly faster, going from >30s to 500ms locally.
Change-Id: I28a2b8c11d4098d9bc44d19b98e19ccc02273098
If A follows B, then we can assume that B does not follow A.
Calling the function recursively computes that twice,
we can instead make some simple changes to "invert" the result.
Change-Id: I709aca7cb997dd2fe3980468a8c6bde6f366fb5b
It's an expensive method, and we previously called it for
every child of the common ancestor, completely unnecessarily.
These changes follow from two observations:
* If there is a $firstPartiallyContainedChild, then the
first fully contained child must follow it; similarly,
if there is a $lastPartiallyContainedChild, then the
last fully contained child must precede it.
* All nodes between the first and last fully contained
children are also fully contained.
Maybe it can be made cleverer still, but it's a lot better.
Change-Id: I4e596c62274c2c0be115f0ddec42629115b430a4
We can check whether a node is a child of another node directly,
without iterating over all its children.
Change-Id: I3a26df89365bf765348d96b477c983ec9c4e43fe
