void
APG::ConstraintSolver::run()
{
if ( !m_readyToRun ) {
error() << "DANGER WILL ROBINSON! A ConstraintSolver (serial no:" << m_serialNumber << ") tried to run before its QueryMaker finished!";
m_abortRequested = true;
return;
}
if ( m_domain.empty() ) {
debug() << "The QueryMaker returned no tracks";
return;
} else {
debug() << "Domain has" << m_domain.size() << "tracks";
}
debug() << "Running ConstraintSolver" << m_serialNumber;
emit totalSteps( m_maxGenerations );
// GENETIC ALGORITHM LOOP
Population population;
quint32 generation = 0;
Meta::TrackList* best = NULL;
while ( !m_abortRequested && ( generation < m_maxGenerations ) ) {
quint32 s = m_constraintTreeRoot->suggestPlaylistSize();
m_suggestedPlaylistSize = (s > 0) ? s : m_suggestedPlaylistSize;
fill_population( population );
best = find_best( population );
if ( population.value( best ) < m_satisfactionThreshold ) {
select_population( population, best );
mutate_population( population );
generation++;
emit incrementProgress();
} else {
break;
}
}
debug() << "solution at" << (void*)(best);
m_solvedPlaylist = best->mid( 0 );
m_finalSatisfaction = m_constraintTreeRoot->satisfaction( m_solvedPlaylist );
/* clean up */
Population::iterator it = population.begin();
while ( it != population.end() ) {
delete it.key();
it = population.erase( it );
}
emit endProgressOperation( this );
}
Meta::TrackList
APG::ConstraintSolver::sample( Meta::TrackList domain, const int sampleSize ) const
{
std::random_shuffle( domain.begin(), domain.end() );
return domain.mid( 0, sampleSize );
}