HBASE-30246 MOB compaction does not close MobCell after resolving ref…

[liuxiaocs7]

…erence cells

• see: HBASE-30246

[Copilot]

Pull request overview

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This PR addresses HBASE-30246 by ensuring MOB reference resolution during compaction properly closes the MobCell and returns a safe, heap-resident copy of the resolved cell to avoid leaking scanners/buffers and referencing recycled NIO buffers.

Changes:

• Introduce DefaultMobStoreCompactor#resolveMobCell(...) that closes MobCell and returns an independent copied ExtendedCell.
• Update compaction paths to use resolveMobCell(...) instead of directly using mobStore.resolve(...).getCell().
• Strengthen tests to use try-with-resources for MobCell and add a unit test verifying close + copy semantics.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
hbase-server/src/main/java/org/apache/hadoop/hbase/mob/DefaultMobStoreCompactor.java	Adds resolveMobCell helper to close resolved MobCell and copy resolved cells safely; compaction updated to use it.
hbase-server/src/test/java/org/apache/hadoop/hbase/mob/FaultyMobStoreCompactor.java	Aligns test compactor implementation with new resolveMobCell behavior.
hbase-server/src/test/java/org/apache/hadoop/hbase/mob/TestDefaultMobStoreCompactor.java	Adds unit test verifying resolveMobCell closes MobCell and returns an independent copy.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestHMobStore.java	Updates resolve test to close MobCell via try-with-resources and dereference via getCell().

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[guluo2016]

Maybe protected ExtendedCell resolveMobCell(ExtendedCell reference, boolean flag) is better？

I think we can also reuse this method in the future if we need to call mobStore.resolve(reference, cacheMobBlocksOnCompaction, true) by this way

[liuxiaocs7]

Thanks @guluo2016 ! The false (readEmptyValueOnMobCellMiss) is coupled to this path's miss handling (it relies on resolve throwing, while true returns an empty cell needing different handling), so it can't be reused as-is. I'd prefer to add the param with a proper name once a real true caller appears, WDYT?