RFR: 8304020: Speed up test/jdk/java/util/zip/ZipFile/TestTooManyEntries.java and clarify its purpose [v6]
Eirik Bjorsnos
duke at openjdk.org
Sun Mar 12 21:25:46 UTC 2023
> 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.
> - By adding a maximally large extra field to the CEN entries, we get away with fewer CEN records and save memory
> - 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 4 seconds on my Macbook Pro. The produced ZIP size was reduced from 5.7 GB to 2 GB. Memory consumption is down from 8GB to something like 12MB.
Eirik Bjorsnos has updated the pull request incrementally with two additional commits since the last revision:
- MAX_EXTRA_FIELD_SIZE can be better expressed as 0xFFFF
- Bring back '@requires sun.arch.data.model == 64' for now
-------------
Changes:
- all: https://git.openjdk.org/jdk/pull/12991/files
- new: https://git.openjdk.org/jdk/pull/12991/files/8969de16..a1a77192
Webrevs:
- full: https://webrevs.openjdk.org/?repo=jdk&pr=12991&range=05
- incr: https://webrevs.openjdk.org/?repo=jdk&pr=12991&range=04-05
Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
Patch: https://git.openjdk.org/jdk/pull/12991.diff
Fetch: git fetch https://git.openjdk.org/jdk pull/12991/head:pull/12991
PR: https://git.openjdk.org/jdk/pull/12991
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