mirror of https://github.com/facebook/rocksdb.git
f3a99e8a4d
Summary: Previously IsInSnapshot assumed that the snapshot is valid at the time that the function is called. However there are cases where that might not be valid. Example is background compactions where the compaction algorithm operates with a list of snapshots some of which might be released by the time they are being passed to IsInSnapshot. The patch make two changes to enable the caller to tell difference: i) any live snapshot below max is added to max_committed_seq_, which allows IsInSnapshot to confidently tell whether the passed snapshot is invalid if it below max, ii) extends IsInSnapshot API with a "released" variable that is set true when IsInSnapshot find no such snapshot below max and also find no other way to give a certain return value. In such cases the return value is true but the caller should also check the "released" boolean after the call. In short here is the changes in the API: i) If the snapshot is valid, no change is required. ii) If the snapshot might be invalid, a reference to "released" boolean must be passed to IsInSnapshot. ii-a) If snapshot is above max, IsInSnapshot can figure the return valid using the commit cache. ii-b) otherwise if snapshot is in old_commit_map_, IsInSnapshot can use that to tell if value was visible to the snapshot. ii-c) otherwise it sets "released" to true and returns true as well. Pull Request resolved: https://github.com/facebook/rocksdb/pull/4856 Differential Revision: D13599847 Pulled By: maysamyabandeh fbshipit-source-id: 1752be28667f886a1efec8cae5714b9b7a8f1e0f |
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| .. | ||
| optimistic_transaction.cc | ||
| optimistic_transaction.h | ||
| optimistic_transaction_db_impl.cc | ||
| optimistic_transaction_db_impl.h | ||
| optimistic_transaction_test.cc | ||
| pessimistic_transaction.cc | ||
| pessimistic_transaction.h | ||
| pessimistic_transaction_db.cc | ||
| pessimistic_transaction_db.h | ||
| snapshot_checker.cc | ||
| transaction_base.cc | ||
| transaction_base.h | ||
| transaction_db_mutex_impl.cc | ||
| transaction_db_mutex_impl.h | ||
| transaction_lock_mgr.cc | ||
| transaction_lock_mgr.h | ||
| transaction_test.cc | ||
| transaction_test.h | ||
| transaction_util.cc | ||
| transaction_util.h | ||
| write_prepared_transaction_test.cc | ||
| write_prepared_txn.cc | ||
| write_prepared_txn.h | ||
| write_prepared_txn_db.cc | ||
| write_prepared_txn_db.h | ||
| write_unprepared_transaction_test.cc | ||
| write_unprepared_txn.cc | ||
| write_unprepared_txn.h | ||
| write_unprepared_txn_db.cc | ||
| write_unprepared_txn_db.h | ||