8296158: Refactor the verification of CDS region checksum

[iklam]

Consolidate the two old functions

• FileMapInfo::region_crc_check(char* buf, size_t size, int expected_crc)
• FileMapInfo::verify_region_checksum(int i)

Into a single function FileMapRegion::check_region_crc().

Also performed some minor renaming and removed a useless API.

---

Progress

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Issue

• JDK-8296158: Refactor the verification of CDS region checksum

Reviewers

• Calvin Cheung (@calvinccheung - Reviewer) ⚠️ Review applies to 3ad8d838
• Matias Saavedra Silva (@matias9927 - Author) ⚠️ Review applies to 10dcd0b1

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[mlbridge]

Webrevs

• 02: Full - Incremental (52a5f4be)
• 01: Full - Incremental (10dcd0b1)
• 00: Full (3ad8d838)

[calvinccheung]

Code refactoring looks good.

[openjdk]

@iklam This change now passes all automated pre-integration checks.

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After integration, the commit message for the final commit will be:

8296158: Refactor the verification of CDS region checksum

Reviewed-by: ccheung, matsaave

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At the time when this comment was updated there had been 4 new commits pushed to the master branch:

• 655a712: 8301444: Port fdlibm hyperbolic transcendental functions to Java
• b242eef: 8280419: Remove dead code related to VerifyThread and verify_thread()
• 4ce493f: 8302225: SunJCE Provider doesn't validate key sizes when using 'constrained' transforms for AES/KW and AES/KWP
• a39cf2e: 8301753: AppendFile/WriteFile has differences between make 3.81 and 4+

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[matias9927]

While I think this is a nice shortcut to avoid checking VerifySharedSpaces, I think it occludes the fact it is a necessary condition in the if statements below. Just my 2 cents but I think it is more intuitive to keep if (VerifySharesSpaces && !check_region_crc()) and keep an assert inside this method.

Either way does work, so go with what you think makes the most sense. Other than that, LGTM!

[iklam]

Thanks for the comment. I fixed the code as you suggested.

[matias9927]

LGTM!

[iklam]

Thanks @matias9927 and @calvinccheung for the review
/integrate

[openjdk]

Going to push as commit 49eb68b.
Since your change was applied there have been 4 commits pushed to the master branch:

• 655a712: 8301444: Port fdlibm hyperbolic transcendental functions to Java
• b242eef: 8280419: Remove dead code related to VerifyThread and verify_thread()
• 4ce493f: 8302225: SunJCE Provider doesn't validate key sizes when using 'constrained' transforms for AES/KW and AES/KWP
• a39cf2e: 8301753: AppendFile/WriteFile has differences between make 3.81 and 4+

Your commit was automatically rebased without conflicts.

[openjdk]

@iklam Pushed as commit 49eb68b.

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