rocksdb/utilities/transactions/pessimistic_transaction_db.h
Maysam Yabandeh 8feee28020 Add skip_cc option to TransactionDB::Write
Summary:
Compared to DB::Write, TransactionDB::Write has the additional overhead of creating and initializing an internal transaction object, as well as the overhead of locking/unlocking the keys. This patch extends the TransactionDB::Write with an skip_cc option to allow the users to indicate that the write batch do not conflict with others and the concurrency control and its overhead can be skipped. TransactionDB::Write by default calls DB::Write when skip_cc is set, which works for WriteCommitted WritePolicy. Any other flavor of TransactionDB that is not compatible with this default behavior (such as WritePreparedTxnDB) can extend ::Write and implement their own approach for taking into account the skip_cc optimization.
Closes https://github.com/facebook/rocksdb/pull/3457

Differential Revision: D6877318

Pulled By: maysamyabandeh

fbshipit-source-id: 56f4e21db87ff71492db4e376fb7c2b03dfeab6b
2018-02-06 15:28:24 -08:00

186 lines
6.9 KiB
C++

// 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 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;
void UpdateCFComparatorMap(const std::vector<ColumnFamilyHandle*>& handles);
void UpdateCFComparatorMap(const ColumnFamilyHandle* handle);
std::map<uint32_t, const Comparator*>* GetCFComparatorMap() {
return cf_map_.load();
}
protected:
DBImpl* db_impl_;
std::shared_ptr<Logger> info_log_;
const TransactionDBOptions txn_db_options_;
// A cache of the cf comparators
std::atomic<std::map<uint32_t, const Comparator*>*> cf_map_;
// GC of the object above
std::unique_ptr<std::map<uint32_t, const Comparator*>> cf_map_gc_;
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;
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_;
};
// 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