RFR: 8352642: Set zipinfo-time=false when constructing zipfs FileSystem in com.sun.tools.javac.file.JavacFileManager$ArchiveContainer for better performance

[Jaikiran Pai]

On Sun, 23 Mar 2025 12:38:04 GMT, Jason Zaugg <jzaugg at openjdk.org> wrote:

> 8352642: Set zipinfo-time=false when constructing zipfs FileSystem in com.sun.tools.javac.file.JavacFileManager$ArchiveContainer for better performance

Hello Jason, I was crafting some JAR files to compose a large classpath and running some compilation tests on a Windows system to see if there's a observable difference with this change. But I see that you have done the necessary testing externally with much more precise checks and those do show the expected improvements with reduced native calls to read. I won't pursue my Windows testing, since what you have is good both from the code change as well as testing point of view. 

> I could create a jtreg test along similar lines. ... The test would construct a JAR that previously triggered one read per entry, and assert that after this change, only a single read is needed to initialize a compiler whose classpath includes that JAR.

I don't think that can be guaranteed/asserted and could lead to an intermittent failing or brittle test.

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PR Comment: https://git.openjdk.org/jdk/pull/24176#issuecomment-2749811146