RFR: 8225763: Inflater and Deflater should implement AutoCloseable [v7]

[Stuart Marks]

On Fri, 15 Nov 2024 11:15:28 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

>> Can I please get a review of this enhancement which proposes to enhance `java.util.zip.Deflater/Inflater` classes to now implement `AutoCloseable`?
>> 
>> The actual work for this was done a few years back when we discussed the proposed approaches and then I raised a RFR. At that time I couldn't take this to completion. The current changes in this PR involve the implementation that was discussed at that time and also have implemented the review suggestions from that time. Here are those previous discussions and reviews:
>> 
>> https://mail.openjdk.org/pipermail/core-libs-dev/2019-June/061079.html
>> https://mail.openjdk.org/pipermail/core-libs-dev/2019-July/061177.html
>> https://mail.openjdk.org/pipermail/core-libs-dev/2019-July/061229.html
>> 
>> To summarize those discussions, we had concluded that:
>> - `Deflater` and `Inflater` will implement the `AutoCloseable` interface
>> -  In the `close()` implementation we will invoke the `end()` method (`end()` can be potentially overridden by subclasses).
>> - `close()` will be specified and implemented to be idempotent. Calling `close()` a second time or more will be a no-op.
>> - Calling `end()` and then `close()`, although uncommon, will also support idempotency and that `close()` call will be a no-op.
>> - However, calling `close()` and then `end()` will not guarantee idempotency and depending on the implementing subclass, the `end()` may throw an exception.
>> 
>> New tests have been included as part of these changes and they continue to pass along with existing tests in tier1, tier2 and tier3. When I had originally added these new tests, I hadn't used junit. I can convert them to junit if that's preferable.
>> 
>> I'll file a CSR shortly.
>
> Jaikiran Pai has updated the pull request incrementally with one additional commit since the last revision:
> 
>   missed a few methods for specifying IllegalStateException

src/java.base/share/classes/java/util/zip/Deflater.java line 892:

> 890:      * and discards any unprocessed input.
> 891:      * <p>
> 892:      * If this method is invoked multiple times, the subsequent calls are treated as a no-op.

I would say,

> If this method is invoked multiple times, the second and subsequent calls do nothing.

src/java.base/share/classes/java/util/zip/Inflater.java line 65:

> 63:  * usage with try-with-resources, this class implements {@link AutoCloseable}. The
> 64:  * {@link #close()} method of this class calls {@code end()} to clean up its
> 65:  * resources. Subclasses are responsible for the cleanup of resources

Once we've agreed on the arrangement in the Deflater class, the corresponding changes should be made to Inflater, mutatis mutandis.

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PR Review Comment: https://git.openjdk.org/jdk/pull/19675#discussion_r1848948353
PR Review Comment: https://git.openjdk.org/jdk/pull/19675#discussion_r1848952003