RFR: 8312089: Simplify and modernize equals, hashCode, and compareTo in java.nio and implementation code [v2]

[Alan Bateman]

On Fri, 14 Jul 2023 13:16:27 GMT, Pavel Rappo <prappo at openjdk.org> wrote:

>> Please review this PR to use modern APIs and language features to simplify equals, hashCode, and compareTo for in java.nio and implementation code.
>> 
>> Please note, test results are pending.
>> 
>> Additional notes:
>> 
>> * This PR saves a volatile read in java.nio.file.attribute.AclEntry.hashCode. Not that it's too important, but worth noting because of rearrangements.
>> 
>> * java.nio.charset.Charset#compareTo seems **inconsistent** with equals. If so, I cannot see where that inconsistency is specified.
>> 
>> * Is this a **bug** in sun.nio.ch.FileKey#hashCode? Tell me if not, I'll revert it.
>> 
>> * This PR simplifies the tail of java.nio.file.attribute.FileTime.compareTo. Unless I'm missing something, that comment in source above the affected lines **seems** not to prohibit such a simplification.
>> 
>> * sun.nio.fs.UnixFileStore#hashCode does not include entry.name(). While it's not wrong, I wonder if it was on purpose.
>> 
>> * Despite its title, this PR also and opportunistically refactors sun.nio.fs.UnixPath.endsWith.
>
> Pavel Rappo has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Address another case from feedback
>  - Address feedback

src/java.base/share/classes/java/nio/charset/Charset.java line 987:

> 985: 
> 986:     /**
> 987:      * {@return the string describing this charset}

You've changed this to "the string", which hints of ==, I think it should be reverted to a "a string".

src/java.base/unix/classes/sun/nio/fs/UnixPath.java line 713:

> 711: 
> 712:         return Arrays.equals(this.path, thisPos, thisLen, that.path, thatPos,
> 713:                 thatLen);

My comment here was "thatLen" ended up on its own line, it can go after thatPos without making it too long.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14886#discussion_r1263932426
PR Review Comment: https://git.openjdk.org/jdk/pull/14886#discussion_r1263936625