File indexing completed on 2024-05-05 04:48:47

 /****************************************************************************************
  * Copyright (c) 2008-2012 Soren Harward <stharward@gmail.com>                          *
  *                                                                                      *
  * 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 APG_CONSTRAINTSOLVER
 #define APG_CONSTRAINTSOLVER
 
 #include "core/meta/forward_declarations.h"
 
 #include <QHash>
 #include <QMutex>
 #include <QString>
 
 #include <ThreadWeaver/Job>
 
 class ConstraintNode;
 
 namespace Collections {
     class QueryMaker;
 }
 
 namespace APG {
     class ConstraintSolver : public QObject, public ThreadWeaver::Job
     {
         Q_OBJECT
 
         public:
             typedef QHash<Meta::TrackList*, double> Population;
 
             static const int QUALITY_RANGE; // allows used to adjust speed/quality tradeoff
 
             ConstraintSolver( ConstraintNode*, int );
             ~ConstraintSolver() override;
 
             Meta::TrackList getSolution() const;
             bool satisfied() const;
             int serial() const { return m_serialNumber; }
             int iterationCount() const { return m_maxGenerations; }
 
             // overloaded ThreadWeaver::Job functions
             bool canBeExecuted();
             bool success() const override;
             void requestAbort() override;
 
         Q_SIGNALS:
             void readyToRun();
             void incrementProgress();
             void totalSteps( int );
             void endProgressOperation( QObject* );
 
             /** This signal is emitted when this job is being processed by a thread. */
             void started(ThreadWeaver::JobPointer);
             /** This signal is emitted when the job has been finished (no matter if it succeeded or not). */
             void done(ThreadWeaver::JobPointer);
             /** This job has failed.
              * This signal is emitted when success() returns false after the job is executed. */
             void failed(ThreadWeaver::JobPointer);
 
         protected:
             void defaultBegin(const ThreadWeaver::JobPointer& job, ThreadWeaver::Thread *thread) override;
             void defaultEnd(const ThreadWeaver::JobPointer& job, ThreadWeaver::Thread *thread) override;
             void run(ThreadWeaver::JobPointer self = QSharedPointer<ThreadWeaver::Job>(), ThreadWeaver::Thread *thread = nullptr) override; // from ThreadWeaver::Job
 
         private Q_SLOTS:
             void receiveQueryMakerData( const Meta::TrackList &);
             void receiveQueryMakerDone();
 
         private:
             int m_serialNumber;                 // a randomly-generated serial number to help with debugging
             double m_satisfactionThreshold;
             double m_finalSatisfaction;
 
             ConstraintNode* const m_constraintTreeRoot;
             Collections::QueryMaker* m_qm;
 
             mutable Meta::TrackList m_domain;   // tracks available to solver
             QMutex m_domainMutex;
             bool m_domainReductionFailed;
             Meta::TrackList m_solvedPlaylist;   // playlist generated by solver
 
             bool m_readyToRun;                  // job execution depends on QueryMaker finishing
             bool m_abortRequested;
 
             // internal mathematical functions
             void fill_population( Population& );
             Meta::TrackList* find_best( const Population& ) const;
             void select_population( Population&, Meta::TrackList* );
             void mutate_population( Population& );
 
             Meta::TrackList* crossover( Meta::TrackList*, Meta::TrackList* ) const;
             static bool pop_comp( double, double );
             Meta::TrackPtr random_track_from_domain() const;
             Meta::TrackList sample( Meta::TrackList, const int ) const;
 
             double rng_gaussian( const double, const double ) const;
             quint32 rng_poisson( const double ) const;
             double rng_uniform() const;
 
             quint32 playlist_size() const;
             bool select( const double ) const;
 
             // convenience function
             void dump_population( const Population& ) const;
 
             // internal mathematical parameters
             quint32 m_maxGenerations;
             quint32 m_populationSize;
             quint32 m_suggestedPlaylistSize;
     };
 } // namespace APG
 
 #endif