Transaction.h

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/*
 * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef _TRANSACTION_H
#define _TRANSACTION_H
 
#include "Define.h"
#include "DatabaseEnvFwd.h"
#include "StringFormat.h"
#include <functional>
#include <mutex>
#include <variant>
#include <vector>
 
class MySQLConnection;
 
struct TransactionData
{
 std::variant<std::unique_ptr<PreparedStatementBase>, std::string> query;
 
 template<typename... Args>
 TransactionData(Args&&... args) : query(std::forward<Args>(args)...) { }
 
 static PreparedStatementBase* ToExecutable(std::unique_ptr<PreparedStatementBase> const& stmt) { return stmt.get(); }
 static char const* ToExecutable(std::string const& sql) { return sql.c_str(); }
};
 
class TC_DATABASE_API TransactionBase
{
 friend class TransactionTask;
 friend class MySQLConnection;
 
 template <typename T>
 friend class DatabaseWorkerPool;
 
 public:
 TransactionBase() : _cleanedUp(false) { }
 TransactionBase(TransactionBase const&) = delete;
 TransactionBase(TransactionBase &&) noexcept = default;
 TransactionBase& operator=(TransactionBase const&) = delete;
 TransactionBase& operator=(TransactionBase &&) noexcept = default;
 virtual ~TransactionBase() { Cleanup(); }
 
 void Append(char const* sql);
 template<typename... Args>
 void PAppend(Trinity::FormatString<Args...> sql, Args&&... args)
 {
 Append(Trinity::StringFormat(sql, std::forward<Args>(args)...).c_str());
 }
 
 std::size_t GetSize() const { return m_queries.size(); }
 
 protected:
 void AppendPreparedStatement(PreparedStatementBase* statement);
 void Cleanup();
 std::vector<TransactionData> m_queries;
 
 private:
 bool _cleanedUp;
};
 
template<typename T>
class Transaction : public TransactionBase
{
public:
 using TransactionBase::Append;
 void Append(PreparedStatement<T>* statement)
 {
 AppendPreparedStatement(statement);
 }
};
 
class TC_DATABASE_API TransactionTask
{
public:
 static bool Execute(MySQLConnection* conn, std::shared_ptr<TransactionBase> trans);
 
private:
 static int TryExecute(MySQLConnection* conn, std::shared_ptr<TransactionBase> trans);
 
 static std::mutex _deadlockLock;
};
 
class TC_DATABASE_API TransactionCallback
{
public:
 TransactionCallback(TransactionFuture&& future) : m_future(std::move(future)) { }
 TransactionCallback(TransactionCallback&&) = default;
 
 TransactionCallback& operator=(TransactionCallback&&) = default;
 
 void AfterComplete(std::function<void(bool)> callback) &
 {
 m_callback = std::move(callback);
 }
 
 bool InvokeIfReady();
 
 TransactionFuture m_future;
 std::function<void(bool)> m_callback;
};
 
#endif