RFR: 8362958: Unnecessary copying / sorting in Streams using Comparator.naturalOrder() [v4]
Patrick Strawderman
duke at openjdk.org
Tue Nov 11 17:56:19 UTC 2025
> When `Comparator.naturalOrder()` was explicitly supplied to a collection such as `TreeSet`, or passed into the `sorted` method of a stream, the sorted characteristic was not preserved, causing unnecessary buffering and duplicate sorting.
>
> Example:
>
>
> TreeSet<Integer> sortedSet = new TreeSet<>(Comparator.naturalOrder());
> sortedSet.add(1);
> sortedSet.add(2);
> // SortedOps.OfRef.opWrapSink is not a no-op
> sortedSet.stream().sorted().forEach(System.out::println);
>
> or
>
> TreeSet<Integer> sortedSet = new TreeSet<>();
> sortedSet.add(1);
> sortedSet.add(2);
> // SortedOps.OfRef.opWrapSink is not a no-op
> sortedSet.stream().sorted(Comparator.naturalOrder()).forEach(System.out::println);
>
>
> This PR updates `SortedOps.makeRef` and `StreamOpFlag.fromCharacteristics` to handle the above cases and avoid the unnecessary sort step.
Patrick Strawderman has updated the pull request incrementally with one additional commit since the last revision:
Fix bad merge
-------------
Changes:
- all: https://git.openjdk.org/jdk/pull/28226/files
- new: https://git.openjdk.org/jdk/pull/28226/files/caeb8f37..4c48f937
Webrevs:
- full: https://webrevs.openjdk.org/?repo=jdk&pr=28226&range=03
- incr: https://webrevs.openjdk.org/?repo=jdk&pr=28226&range=02-03
Stats: 4 lines in 1 file changed: 0 ins; 2 del; 2 mod
Patch: https://git.openjdk.org/jdk/pull/28226.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/28226/head:pull/28226
PR: https://git.openjdk.org/jdk/pull/28226
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