On Sat, 5 Feb 2022 20:29:50 GMT, Xue-Lei Andrew Fan <xue...@openjdk.org> wrote:
> In [JDK-8281289](https://bugs.openjdk.java.net/browse/JDK-8281289), the > SSLParameters class was updated with the patch: > > - return Collections.<SNIServerName>unmodifiableList(new > ArrayList<>(sniNames.values())); > + return List.copyOf(sniNames.values()); > > However, there's a small compatibility risk with this change, > `List.copyOf(...).contains(null)` will throw NPE while > `Collections.unmodifiableList(...).contains(null)` won't. It may be not > worthy of the risk although the impact may be minimal. > > This update will re-use the Collections.unmodifiableList() methods, but > re-org the code for better performance. This looks like an appropriate solution which avoids the minor compatibility risk introduced by the previous change - and you might even end up being more efficient both when setting and reading the names/matchers. (Since we're going down the route of optimizing this: the `type` of a `SNIServerName` is constrained to a value between 0 and 255, so there's likely a small micro-optimization opportunity in using a `BitSet` for the duplicate checking rather a `ArrayList<Integer>`.. A `BitSet(256)` should have lower memory use and the existence check will run in O(1) instead of O(n) time. Might not be worthwhile to optimize these setters, though..) ------------- Marked as reviewed by redestad (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/7359
