qt-creator/src/libs/sqlite/sqlitetransaction.h

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**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Creator.
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** GNU General Public License Usage
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** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
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#pragma once

#include "sqliteglobal.h"

#include <mutex>

namespace Sqlite {

class DatabaseBackend;
class Database;

template <typename Database>
class AbstractTransaction
{
public:
    ~AbstractTransaction()
    {
        if (!m_isAlreadyCommited)
            m_database.execute("ROLLBACK");
    }

    void commit()
    {
        m_database.execute("COMMIT");
        m_isAlreadyCommited = true;
    }

protected:
    AbstractTransaction(Database &database)
        : m_databaseLock(database.databaseMutex()),
          m_database(database)
    {
    }

private:
    std::lock_guard<typename Database::MutexType> m_databaseLock;
    Database &m_database;
    bool m_isAlreadyCommited = false;
};

template <typename Database>
class DeferredTransaction final : public AbstractTransaction<Database>
{
public:
    DeferredTransaction(Database &database)
        : AbstractTransaction<Database>(database)
    {
        database.execute("BEGIN");
    }
};

template <typename Database>
class ImmediateTransaction final : public AbstractTransaction<Database>
{
public:
    ImmediateTransaction(Database &database)
        : AbstractTransaction<Database>(database)
    {
        database.execute("BEGIN IMMEDIATE");
    }
};

template <typename Database>
class ExclusiveTransaction final : public AbstractTransaction<Database>
{
public:
    ExclusiveTransaction(Database &database)
        : AbstractTransaction<Database>(database)
    {
        database.execute("BEGIN EXCLUSIVE");
    }
};

} // namespace Sqlite