RFR: 8304020: Speed up test/jdk/java/util/zip/ZipFile/TestTooManyEntries.java and clarify its purpose [v3]

[Alan Bateman]

On Sun, 12 Mar 2023 10:00:50 GMT, Eirik Bjorsnos <duke at openjdk.org> wrote:

>> Please review this PR which speeds up TestTooManyEntries and clarifies its purpose:
>> 
>> - The name 'TestTooManyEntries' does not clearly convey the purpose of the test. What is tested is the validation that the total CEN size fits in a Java byte array. Suggested rename: CenSizeTooLarge
>> - The test creates DEFLATED entries which incurs zlib costs and File Data / Data Descriptors for no additional benefit. We can use STORED instead.
>> - By creating a single LocalDateTime and setting it with `ZipEntry.setTimeLocal`, we can avoid repeated time zone calculations. 
>> - The name of entries is generated by calling UUID.randomUUID, we could use simple counter instead.
>> - The produced file is unnecessarily large. We know how large a CEN entry is, let's take advantage of that to create a file with the minimal size.
>> - The summary and comments of the test can be improved to help explain the purpose of the test and how we reach the limit being tested.
>> 
>> These speedups reduced the runtime from 4 min 17 sec to 1 min 54 sec on my Macbook Pro. The produced ZIP size was reduced from 5.7 GB to 3.5 GB.
>
> Eirik Bjorsnos has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Use Integer.toString instead of Long.toString

It would be great if we could change this to be an automatic test. Maybe we could create a sub-directory in test/jdk/java/util/zip/ZipFile for the resource hogs and put this here, exclude this directory from tier1, and add it to tier2_part2.

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PR: https://git.openjdk.org/jdk/pull/12991