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diff --git a/src/rocksdb/utilities/transactions/pessimistic_transaction_db.h b/src/rocksdb/utilities/transactions/pessimistic_transaction_db.h
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+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+#ifndef ROCKSDB_LITE
+
+#include <mutex>
+#include <queue>
+#include <set>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "db/db_iter.h"
+#include "db/read_callback.h"
+#include "db/snapshot_checker.h"
+#include "rocksdb/db.h"
+#include "rocksdb/options.h"
+#include "rocksdb/utilities/transaction_db.h"
+#include "utilities/transactions/pessimistic_transaction.h"
+#include "utilities/transactions/transaction_lock_mgr.h"
+#include "utilities/transactions/write_prepared_txn.h"
+
+namespace rocksdb {
+
+class PessimisticTransactionDB : public TransactionDB {
+ public:
+  explicit PessimisticTransactionDB(DB* db,
+                                    const TransactionDBOptions& txn_db_options);
+
+  explicit PessimisticTransactionDB(StackableDB* db,
+                                    const TransactionDBOptions& txn_db_options);
+
+  virtual ~PessimisticTransactionDB();
+
+  virtual const Snapshot* GetSnapshot() override { return db_->GetSnapshot(); }
+
+  virtual Status Initialize(
+      const std::vector<size_t>& compaction_enabled_cf_indices,
+      const std::vector<ColumnFamilyHandle*>& handles);
+
+  Transaction* BeginTransaction(const WriteOptions& write_options,
+                                const TransactionOptions& txn_options,
+                                Transaction* old_txn) override = 0;
+
+  using StackableDB::Put;
+  virtual Status Put(const WriteOptions& options,
+                     ColumnFamilyHandle* column_family, const Slice& key,
+                     const Slice& val) override;
+
+  using StackableDB::Delete;
+  virtual Status Delete(const WriteOptions& wopts,
+                        ColumnFamilyHandle* column_family,
+                        const Slice& key) override;
+
+  using StackableDB::SingleDelete;
+  virtual Status SingleDelete(const WriteOptions& wopts,
+                              ColumnFamilyHandle* column_family,
+                              const Slice& key) override;
+
+  using StackableDB::Merge;
+  virtual Status Merge(const WriteOptions& options,
+                       ColumnFamilyHandle* column_family, const Slice& key,
+                       const Slice& value) override;
+
+  using TransactionDB::Write;
+  virtual Status Write(const WriteOptions& opts, WriteBatch* updates) override;
+
+  using StackableDB::CreateColumnFamily;
+  virtual Status CreateColumnFamily(const ColumnFamilyOptions& options,
+                                    const std::string& column_family_name,
+                                    ColumnFamilyHandle** handle) override;
+
+  using StackableDB::DropColumnFamily;
+  virtual Status DropColumnFamily(ColumnFamilyHandle* column_family) override;
+
+  Status TryLock(PessimisticTransaction* txn, uint32_t cfh_id,
+                 const std::string& key, bool exclusive);
+
+  void UnLock(PessimisticTransaction* txn, const TransactionKeyMap* keys);
+  void UnLock(PessimisticTransaction* txn, uint32_t cfh_id,
+              const std::string& key);
+
+  void AddColumnFamily(const ColumnFamilyHandle* handle);
+
+  static TransactionDBOptions ValidateTxnDBOptions(
+      const TransactionDBOptions& txn_db_options);
+
+  const TransactionDBOptions& GetTxnDBOptions() const {
+    return txn_db_options_;
+  }
+
+  void InsertExpirableTransaction(TransactionID tx_id,
+                                  PessimisticTransaction* tx);
+  void RemoveExpirableTransaction(TransactionID tx_id);
+
+  // If transaction is no longer available, locks can be stolen
+  // If transaction is available, try stealing locks directly from transaction
+  // It is the caller's responsibility to ensure that the referred transaction
+  // is expirable (GetExpirationTime() > 0) and that it is expired.
+  bool TryStealingExpiredTransactionLocks(TransactionID tx_id);
+
+  Transaction* GetTransactionByName(const TransactionName& name) override;
+
+  void RegisterTransaction(Transaction* txn);
+  void UnregisterTransaction(Transaction* txn);
+
+  // not thread safe. current use case is during recovery (single thread)
+  void GetAllPreparedTransactions(std::vector<Transaction*>* trans) override;
+
+  TransactionLockMgr::LockStatusData GetLockStatusData() override;
+
+  std::vector<DeadlockPath> GetDeadlockInfoBuffer() override;
+  void SetDeadlockInfoBufferSize(uint32_t target_size) override;
+
+  // The default implementation does nothing. The actual implementation is moved
+  // to the child classes that actually need this information. This was due to
+  // an odd performance drop we observed when the added std::atomic member to
+  // the base class even when the subclass do not read it in the fast path.
+  virtual void UpdateCFComparatorMap(const std::vector<ColumnFamilyHandle*>&) {}
+  virtual void UpdateCFComparatorMap(ColumnFamilyHandle*) {}
+
+ protected:
+  DBImpl* db_impl_;
+  std::shared_ptr<Logger> info_log_;
+  const TransactionDBOptions txn_db_options_;
+
+  void ReinitializeTransaction(
+      Transaction* txn, const WriteOptions& write_options,
+      const TransactionOptions& txn_options = TransactionOptions());
+
+  virtual Status VerifyCFOptions(const ColumnFamilyOptions& cf_options);
+
+ private:
+  friend class WritePreparedTxnDB;
+  friend class WritePreparedTxnDBMock;
+  friend class WriteUnpreparedTxn;
+  friend class TransactionTest_DoubleEmptyWrite_Test;
+  friend class TransactionTest_DuplicateKeys_Test;
+  friend class TransactionTest_PersistentTwoPhaseTransactionTest_Test;
+  friend class TransactionStressTest_TwoPhaseLongPrepareTest_Test;
+  friend class TransactionTest_TwoPhaseDoubleRecoveryTest_Test;
+  friend class TransactionTest_TwoPhaseOutOfOrderDelete_Test;
+  friend class WriteUnpreparedTransactionTest_RecoveryTest_Test;
+  friend class WriteUnpreparedTransactionTest_MarkLogWithPrepSection_Test;
+  TransactionLockMgr lock_mgr_;
+
+  // Must be held when adding/dropping column families.
+  InstrumentedMutex column_family_mutex_;
+  Transaction* BeginInternalTransaction(const WriteOptions& options);
+
+  // Used to ensure that no locks are stolen from an expirable transaction
+  // that has started a commit. Only transactions with an expiration time
+  // should be in this map.
+  std::mutex map_mutex_;
+  std::unordered_map<TransactionID, PessimisticTransaction*>
+      expirable_transactions_map_;
+
+  // map from name to two phase transaction instance
+  std::mutex name_map_mutex_;
+  std::unordered_map<TransactionName, Transaction*> transactions_;
+
+  // Signal that we are testing a crash scenario. Some asserts could be relaxed
+  // in such cases.
+  virtual void TEST_Crash() {}
+};
+
+// A PessimisticTransactionDB that writes the data to the DB after the commit.
+// In this way the DB only contains the committed data.
+class WriteCommittedTxnDB : public PessimisticTransactionDB {
+ public:
+  explicit WriteCommittedTxnDB(DB* db,
+                               const TransactionDBOptions& txn_db_options)
+      : PessimisticTransactionDB(db, txn_db_options) {}
+
+  explicit WriteCommittedTxnDB(StackableDB* db,
+                               const TransactionDBOptions& txn_db_options)
+      : PessimisticTransactionDB(db, txn_db_options) {}
+
+  virtual ~WriteCommittedTxnDB() {}
+
+  Transaction* BeginTransaction(const WriteOptions& write_options,
+                                const TransactionOptions& txn_options,
+                                Transaction* old_txn) override;
+
+  // Optimized version of ::Write that makes use of skip_concurrency_control
+  // hint
+  using TransactionDB::Write;
+  virtual Status Write(const WriteOptions& opts,
+                       const TransactionDBWriteOptimizations& optimizations,
+                       WriteBatch* updates) override;
+};
+
+}  //  namespace rocksdb
+#endif  // ROCKSDB_LITE