RFR: 8303891: Speed up Zip64SizeTest using a small ZIP64 file [v5]

[Jaikiran Pai]

On Thu, 8 Feb 2024 14:09:35 GMT, Eirik Bjørsnøs <eirbjo at openjdk.org> wrote:

>> Please review this PR which suggests we speed up the `Zip64SizeTest` using a small-sized ZIP64 ZIP file specifically created to reproduce the issue being tested.
>> 
>> The disk space requirement of this test is known to cause problems in some builds, see [JDK-8259866](https://bugs.openjdk.org/browse/JDK-8259866)
>> 
>> By using a sparse file, we reduce consumed disk space from 5GB to 266 bytes and also reduce the runtime from ~35 seconds to ~1 seconds on my Macbook Pro.
>> 
>> The PR also fixes the `@summary` tag, which seems to have been copied from an unrelated test.
>
> Eirik Bjørsnøs has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 13 additional commits since the last revision:
> 
>  - Use a small ZIP64 file to reproduce the issue. Convert test to JUnit
>  - Update copyright year for 2024
>  - Use ENTRY instead of FILE when refering to names and sizes of file entries in the ZIP file
>  - Merge branch 'master' into zip64-size-test-sparse
>  - Merge branch 'master' into zip64-size-test-sparse
>  - Sparse files must be created explicitly on NTFS
>  - Merge branch 'master' into zip64-size-test-sparse
>  - Merge branch 'master' into zip64-size-test-sparse
>  - Make test method public
>  - Add a missing "when" in Javadocs for SparseOutputStream
>  - ... and 3 more: https://git.openjdk.org/jdk/compare/d01414fa...41b2ba5e

test/jdk/java/util/zip/ZipFile/Zip64SizeTest.java line 112:

> 110:             ZipEntry e1 = new ZipEntry("first");
> 111:             // Make room for an 8-byte ZIP64 extra field
> 112:             e1.setExtra(createOpaqueExtra((short) Long.BYTES));

Hello Eirik, I couldn't understand why we first add a opaque extra field first and then update it to be a zip64 extra field. Why do we do this?

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PR Review Comment: https://git.openjdk.org/jdk/pull/12948#discussion_r1483943970