RFR: JDK-8199216: Memory leak and quadratic layout time with nested nodes (hbox) and pseudo-class in style sheet [v3]

[John Hendrikx]

On Sat, 8 Apr 2023 17:37:27 GMT, Michael Strauß <mstrauss at openjdk.org> wrote:

>>> I could cache the hash code for the sets that are returned here (they are immutable sets returned by `Set.copyOf` -- I checked their code, and they don't cache the hash codes). That would however only help if you often pass in a set that is already cached, to find out if you got the same one. Perhaps this happens a lot, I could test that.
>> 
>> That's what I meant to say. It seems like an easy win to cache the hash code of immutable sets if those same immutable sets can concievably be passed into this method quite often.
>
>> Allocations only occur in two cases:
>> 
>> * When the set you pass in is not immutable, and it is a new set that wasn't cached yet.  A copy is made (allocation) and a `Map.Entry` is created (allocation)
>> * When the set you pass in is immutable, but wasn't cached yet.  No copy is needed, but still a `Map.Entry` is created.
> 
> This method will allocate on every single call because it captures the method argument in a lambda object (but it doesn't need to, it can be written in a way that doesn't use capturing lambdas). That's another easy win to be had if this method is called often.

@mstr2 I've optimized this now without the lambda as you suggested.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1076#discussion_r1176095204