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 /* This file is part of the KDE project
    Copyright (C) 2003-2017 Jarosław Staniek <staniek@kde.org>
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library 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
    Library General Public License for more details.
 
    You should have received a copy of the GNU Library General Public License
    along with this program; see the file COPYING.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
 */
 
 #ifndef KDB_TRANSACTION_H
 #define KDB_TRANSACTION_H
 
 #include "config-kdb.h"
 #include "kdb_export.h"
 
 #include <QtGlobal>
 
 class KDbConnection;
 class KDbTransactionData;
 
 /**
  * @brief This class encapsulates a single database transaction
  *
  * The KDbTransaction handle abstracts a database transaction for given database connection.
  * Transaction objects are value-based, implicitly shared.
  *
  * Lifetime of the transaction object is closely related to a KDbConnection object.
  * Deleting the either instance does not commit or rollback the actual transaction.
  * Use KDbTransactionGuard for automatic commits or rolls back.
  *
  * @see KDbConnection::beginTransaction()
  */
 class KDB_EXPORT KDbTransaction
 {
 public:
     /**
      * @brief Constructs a null transaction.
      *
      * @note It can be initialized only by KDbConnection.
      */
     KDbTransaction();
 
     /**
      * @brief Copy constructor
      */
     KDbTransaction(const KDbTransaction& trans);
 
     ~KDbTransaction();
 
     //! Options for commiting and rolling back transactions
     //! @see KDbConnection::beginTransaction() KDbConnection::rollbackTransaction()
     //! @see KDbTransactionGuard::commit() KDbTransactionGuard::rollback()
     enum class CommitOption {
         None = 0,
         IgnoreInactive = 1 //!< Do not return error for inactive or null transactions when
                            //!< requesting commit or rollback
     };
     Q_DECLARE_FLAGS(CommitOptions, CommitOption)
 
     KDbTransaction& operator=(const KDbTransaction& trans);
 
     /**
      * @brief Returns @c true if this transaction is equal to @a other; otherwise returns @c false
      *
      * Two transactions are equal if they encapsulate the same physical transaction,
      * i.e. copy constructor or assignment operator was used.
      * Two null transaction objects are equal.
      */
     bool operator==(const KDbTransaction& other) const;
 
     //! @return @c true if this transaction is not equal to @a other; otherwise returns @c false.
     //! @since 3.1
     inline bool operator!=(const KDbTransaction &other) const { return !operator==(other); }
 
     /**
      * @brief Returns database connection for which the transaction belongs.
      *
      * @c nullptr is returned for null transactions.
      */
     KDbConnection* connection();
 
     //! @overload
     //! @since 3.1
     const KDbConnection* connection() const;
 
     /**
      * @brief Returns @c true if transaction is active (i.e. started)
      *
      * @return @c false also if transaction is uninitialised (null) or not started.
      * @see KDbConnection::beginTransaction()
      * @since 3.1
      */
     bool isActive() const;
 
     /**
      * @brief Returns @c true if this transaction is null.
      *
      * Null implies !isActive().
      */
     bool isNull() const;
 
 #ifdef KDB_TRANSACTIONS_DEBUG
     //! Helper for debugging, returns value of global transaction data reference counter
     static int globalCount();
 #endif
 
 protected:
     KDbTransactionData *m_data;
 
     friend class KDbConnection;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(KDbTransaction::CommitOptions)
 
 #endif