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rocksdb/utilities/transactions/optimistic_transaction_impl.h

90 lines
2.7 KiB

// Copyright (c) 2015, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
#pragma once
#ifndef ROCKSDB_LITE
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>
#include "db/write_callback.h"
#include "rocksdb/db.h"
#include "rocksdb/slice.h"
#include "rocksdb/snapshot.h"
#include "rocksdb/status.h"
#include "rocksdb/types.h"
#include "rocksdb/utilities/transaction.h"
#include "rocksdb/utilities/optimistic_transaction_db.h"
#include "rocksdb/utilities/write_batch_with_index.h"
#include "utilities/transactions/transaction_base.h"
#include "utilities/transactions/transaction_util.h"
namespace rocksdb {
class OptimisticTransactionImpl : public TransactionBaseImpl {
public:
OptimisticTransactionImpl(OptimisticTransactionDB* db,
const WriteOptions& write_options,
const OptimisticTransactionOptions& txn_options);
virtual ~OptimisticTransactionImpl();
Status Commit() override;
void Rollback() override;
uint64_t GetNumKeys() const override;
const TransactionKeyMap* GetTrackedKeys() const { return &tracked_keys_; }
protected:
Status TryLock(ColumnFamilyHandle* column_family, const Slice& key,
bool untracked = false) override;
private:
OptimisticTransactionDB* const txn_db_;
// Map of Column Family IDs to keys and corresponding sequence numbers.
// The sequence number stored for a key will be used during commit to make
// sure this key has
// not changed since this sequence number.
TransactionKeyMap tracked_keys_;
friend class OptimisticTransactionCallback;
// Returns OK if it is safe to commit this transaction. Returns Status::Busy
// if there are read or write conflicts that would prevent us from committing
// OR if we can not determine whether there would be any such conflicts.
//
// Should only be called on writer thread.
Status CheckTransactionForConflicts(DB* db);
void Clear() override;
// No copying allowed
OptimisticTransactionImpl(const OptimisticTransactionImpl&);
void operator=(const OptimisticTransactionImpl&);
};
// Used at commit time to trigger transaction validation
class OptimisticTransactionCallback : public WriteCallback {
public:
explicit OptimisticTransactionCallback(OptimisticTransactionImpl* txn)
: txn_(txn) {}
Status Callback(DB* db) override {
return txn_->CheckTransactionForConflicts(db);
}
private:
OptimisticTransactionImpl* txn_;
};
} // namespace rocksdb
#endif // ROCKSDB_LITE