File indexing completed on 2025-01-05 03:53:59

 /* ============================================================
  *
  * This file is a part of digiKam project
  * https://www.digikam.org
  *
  * Date        : 2010-10-12
  * Description : Core database convenience object for grouping operations
  *
  * SPDX-FileCopyrightText: 2010 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  *
  * ============================================================ */
 
 #ifndef DIGIKAM_CORE_DB_OPERATION_GROUP_H
 #define DIGIKAM_CORE_DB_OPERATION_GROUP_H
 
 // Qt includes
 
 #include <QVariant>
 
 // Local includes
 
 #include "digikam_export.h"
 
 namespace Digikam
 {
 
 class CoreDbAccess;
 
 /**
  * When you intend to execute a number of write operations to the database,
  * group them while holding a CoreDbOperationGroup.
  * For some database systems (SQLite), keeping a transaction across write operations
  * occurring in short time results in enormous speedup (800x).
  * For system that do not need this optimization, this class is a no-op.
  */
 class DIGIKAM_DATABASE_EXPORT CoreDbOperationGroup
 {
 public:
 
     /**
      * Retrieve a CoreDbAccess object each time when constructing and destructing.
      */
     CoreDbOperationGroup();
 
     /**
      * Use an existing CoreDbAccess object, which must live as long as this object exists.
      */
     explicit CoreDbOperationGroup(CoreDbAccess* const access);
     ~CoreDbOperationGroup();
 
     /**
      * This will - if a transaction is held - commit the transaction and acquire a new one.
      * This may improve concurrent access.
      */
     void lift();
 
     void setMaximumTime(int msecs);
 
     /**
      * Resets to 0 the time used by allowLift()
      */
     void resetTime();
 
     /**
      * Allows to lift(). The transaction will be lifted if the time set by setMaximumTime()
      * has expired.
      */
     void allowLift();
 
 private:
 
     // Disable
     CoreDbOperationGroup(const CoreDbOperationGroup&)            = delete;
     CoreDbOperationGroup& operator=(const CoreDbOperationGroup&) = delete;
 
     class Private;
     Private* const d;
 };
 
 } // namespace Digikam
 
 #endif // DIGIKAM_CORE_DB_OPERATION_GROUP_H