RFR: 8376294: ZipFile.Source.Key should not hold on to its BasicFileAttributes instance

[Alan Bateman]

On Mon, 26 Jan 2026 10:23:16 GMT, Eirik Bjørsnøs <eirbjo at openjdk.org> wrote:

> Please review this small enhancement which makes `ZipFile.Source.Key` capture the relevant `BasicFileAttributes` fields eagerly in its constructor instead of calling into `BasicFileAttributes` for each `hashCode` or `equals` invocation.
> 
> This reduces the memory footprint of `Key` instances. It should be performance positive since we avoid creating `FileTime` instances once per comparison and avoid synchronization getting the file key. 
> 
> Capturing fields early also improves readability by making it obvious from the field declarations what information Key uses when comparing equality.
> 
> Pure refactoring, no tests updated, `noreg-trivial`.

I think this should be okay, and low risk.

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PR Comment: https://git.openjdk.org/jdk/pull/29411#issuecomment-3799756024