[OAK-4276] Refactor / rework compaction strategies

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Segment Tar 0.0.2, 1.6.0
• Component/s: segment-tar
• Labels: compaction gc technical_debt
• Epic Link: SegmentMK revision GC
• Assignee: Michael Dürig
• Reporter: Michael Dürig
• Created: 22/Apr/16 14:05
• Updated: 27/Jun/16 08:22
• Resolved: 26/Apr/16 15:12

Description

After the changes from OAK-3348 many if not all of the options in CompactionStrategy do not apply any more. Specifically the new "brutal" strategy is hard coded to always be in effect. We need to:

• Decide which cleanup methods we want to keep supporting,
• decide which options to expose through CompactionStrategy. E.g. cloneBinaries was so far always set to false and I would opt to remove the option as implementing might be tricky with the de-duplication cache based compaction we now have,
• optimally refactor CompactionStrategy into a proper abstract data type.

Issue Links

• relates to: OAK-3348 Cross gc sessions might introduce references to pre-compacted segments