77 lines
2.4 KiB
C++
77 lines
2.4 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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#pragma once
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#ifndef ROCKSDB_LITE
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#include <string>
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#include <vector>
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#include "rocksdb/comparator.h"
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#include "rocksdb/db.h"
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namespace rocksdb {
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class Transaction;
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// Database with Transaction support.
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//
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// See optimistic_transaction.h and examples/transaction_example.cc
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// Options to use when starting an Optimistic Transaction
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struct OptimisticTransactionOptions {
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// Setting set_snapshot=true is the same as calling SetSnapshot().
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bool set_snapshot = false;
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// Should be set if the DB has a non-default comparator.
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// See comment in WriteBatchWithIndex constructor.
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const Comparator* cmp = BytewiseComparator();
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};
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class OptimisticTransactionDB {
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public:
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// Open an OptimisticTransactionDB similar to DB::Open().
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static Status Open(const Options& options, const std::string& dbname,
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OptimisticTransactionDB** dbptr);
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static Status Open(const DBOptions& db_options, const std::string& dbname,
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const std::vector<ColumnFamilyDescriptor>& column_families,
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std::vector<ColumnFamilyHandle*>* handles,
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OptimisticTransactionDB** dbptr);
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virtual ~OptimisticTransactionDB() {}
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// Starts a new Transaction.
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//
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// Caller is responsible for deleting the returned transaction when no
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// longer needed.
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//
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// If old_txn is not null, BeginTransaction will reuse this Transaction
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// handle instead of allocating a new one. This is an optimization to avoid
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// extra allocations when repeatedly creating transactions.
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virtual Transaction* BeginTransaction(
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const WriteOptions& write_options,
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const OptimisticTransactionOptions& txn_options =
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OptimisticTransactionOptions(),
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Transaction* old_txn = nullptr) = 0;
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// Return the underlying Database that was opened
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virtual DB* GetBaseDB() = 0;
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protected:
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// To Create an OptimisticTransactionDB, call Open()
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explicit OptimisticTransactionDB(DB* db) {}
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OptimisticTransactionDB() {}
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private:
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// No copying allowed
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OptimisticTransactionDB(const OptimisticTransactionDB&);
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void operator=(const OptimisticTransactionDB&);
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};
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} // namespace rocksdb
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#endif // ROCKSDB_LITE
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