File indexing completed on 2024-05-19 04:49:26

 /****************************************************************************************
  * Copyright (c) 2009 Maximilian Kossick <maximilian.kossick@googlemail.com>            *
  * Copyright (c) 2012 Matěj Lait <matej@laitl.cz>                                       *
  *                                                                                      *
  * 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 PERSISTENTSTATISTICSSTORE_H
 #define PERSISTENTSTATISTICSSTORE_H
 
 #include "amarok_export.h"
 #include "core/meta/Observer.h"
 #include "core/meta/Statistics.h"
 
 #include <QDateTime>
 #include <QReadWriteLock>
 
 /**
  * Base class for all permanent statistics storage providers. Use one of the subclassed if
  * your collection cannot store statistics (rating, play count..) natively, but you still
  * want to provide the functionality.
  *
  * All subclasses automatically call notifyObservers() on your track when the statistics
  * change. PersistentStatisticsStore uses some trickery not to hold reference to your
  * track to avoid circular reference counting. PersistentStatisticsStore can even deal
  * with your track being destroyed and is implemented in thread-safe way. You should
  * store is as StatisticsPtr (a AmarokSharedPointer) in your Track class.
  */
 class AMAROK_EXPORT PersistentStatisticsStore : public Meta::Statistics, private Meta::Observer
 {
     public:
         /**
          * Create persistent statistics store of @param track statistics. @p track may
          * not be null.
          *
          * This methods takes plain pointer so that you can call it in the Track
          * constructor without AmarokSharedPointer deleting it right away.
          */
         explicit PersistentStatisticsStore( Meta::Track *track );
         ~PersistentStatisticsStore() override;
 
         // Meta::Statistics methods
         double score() const override;
         void setScore( double newScore ) override;
 
         int rating() const override;
         void setRating( int newRating ) override;
 
         QDateTime lastPlayed() const override;
         void setLastPlayed( const QDateTime &dt ) override;
 
         QDateTime firstPlayed() const override;
         void setFirstPlayed( const QDateTime &dt ) override;
 
         int playCount() const override;
         void setPlayCount( int playCount ) override;
 
         void beginUpdate() override;
         void endUpdate() override;
 
         // Meta::Observer methods
 
         /**
          * Notice that the linked track was destroyed.
          */
         void entityDestroyed() override;
 
     protected:
         virtual void save() = 0; // called with m_lock locked for writing!
 
         static const QString s_sqlDateFormat;
 
         Meta::Track *m_track; // plain pointer not to hold reference
         QDateTime m_lastPlayed;
         QDateTime m_firstPlayed;
         double m_score;
         int m_rating;
         int m_playCount;
         mutable QReadWriteLock m_lock; // lock protecting access to fields.
 
     private:
         void commitIfInNonBatchUpdate(); // must be called with the m_lock locked for writing
 
         /**
          * Number of current batch operations started by @see beginUpdate() and not
          * yet ended by @see endUpdate(). Must only be accessed with m_track held.
          */
         int m_batch;
 };
 
 #endif // PERSISTENTSTATISTICSSTORE_H