RFR: 8293499: Provide jmod --compress option [v3]
Mandy Chung
mchung at openjdk.org
Mon Sep 12 19:00:57 UTC 2022
On Mon, 12 Sep 2022 18:34:12 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:
>> I have been looking into `make clean-images images` performance, and realized jmod keeps compressing files with default compression level. Tuning that toward lighter compression levels improves build performance considerably, without a heavy loss in *.jmod sizes.
>>
>> This PR allows JMOD to select the compression level. Follow-ups would use this in the build system, see #10214.
>>
>> The interesting asymmetry against `jlink` is: `jlink` provides `--compress` option that only takes `2` for "ZIP compression". (Separately, we could argue if it would be beneficial to extend `--compress` to `jlink` as well, so to select the compression level there too.)
>
> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
>
> Adopt "--compress zip-[0-9]" as option format
I also like the new `--compress` option taking `zip-0, zip-1,... zip-9` values.
src/jdk.jlink/share/classes/jdk/tools/jmod/JmodOutputStream.java line 58:
> 56: * returning the output stream to write to the JMOD file.
> 57: */
> 58: static JmodOutputStream newOutputStream(Path file, LocalDateTime date, int compLevel) throws IOException {
Suggest to name this parameter `compressLevel` to make it clear.
src/jdk.jlink/share/classes/jdk/tools/jmod/JmodTask.java line 171:
> 169: Path extractDir;
> 170: LocalDateTime date;
> 171: int compLevel;
s/compLevel/compressLevel/
src/jdk.jlink/share/classes/jdk/tools/jmod/JmodTask.java line 1191:
> 1189: if (idx != lastIdx) {
> 1190: throw new CommandException("err.compress.incorrect", value);
> 1191: }
what about checking `value.substring(0, idx)` is "zip"?
test/jdk/tools/jmod/JmodTest.java line 807:
> 805: jmod("create",
> 806: "--class-path", cp,
> 807: "--compress", "test",
good to have a test case verifying "test-0" value.
-------------
PR: https://git.openjdk.org/jdk/pull/10213
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