Summary:
When `--sync_fault_injection` is set, this PR takes a snapshot of the expected values and starts an operation trace when the DB is opened. These files are stored in `--expected_values_dir`. They will be used for recovering the expected state of the DB following a crash where a suffix of unsynced operations are allowed to be lost.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8960
Test Plan: injected crashed at various points in `FileExpectedStateManager` and verified the next run recovers the state/trace file with highest seqno and removes all older/temporary files. Note we don't use sync_fault_injection in CI crash tests yet.
Reviewed By: pdillinger
Differential Revision: D31194941
Pulled By: ajkr
fbshipit-source-id: b0f935a529a0186c5a9c7709fcaa8829de8a84cf