Summary:
Some changes to make it easier to make FilterPolicy
customizable. Especially, create distinct classes for the different
testing-only and user-facing built-in FilterPolicy modes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9567
Test Plan:
tests updated, with no intended difference in functionality
tested. No difference in test performance seen as a result of moving to
string-based filter type configuration.
Reviewed By: mrambacher
Differential Revision: D34234694
Pulled By: pdillinger
fbshipit-source-id: 8a94931a9e04c3bcca863a4f524cfd064aaf0122