Restored audio simimarity based classifier

src/libs/recommendation/CMakeLists.txt

@@ -1,8 +1,10 @@
 
 add_library(lmsrecommendation SHARED
 	impl/clusters/ClustersClassifier.cpp
+	impl/features/FeaturesClassifierCache.cpp
+	impl/features/FeaturesClassifier.cpp
+	impl/features/FeaturesDefs.cpp
 	impl/Engine.cpp
-	impl/ClassifierCreator.cpp
 	)
 
 target_include_directories(lmsrecommendation INTERFACE

src/libs/recommendation/impl/ClassifierCreator.cpp

@@ -1,33 +0,0 @@
-/*
- * Copyright (C) 2020 Emeric Poupon
- *
- * This file is part of LMS.
- *
- * LMS 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 3 of the License, or
- * (at your option) any later version.
- *
- * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "recommendation/FeaturesClassifierCreator.hpp"
-#include "recommendation/IClassifier.hpp"
-
-namespace Recommendation
-{
-
-	std::unique_ptr<IClassifier> createFeaturesClassifier()
-	{
-		return {};
-	}
-	
-
-}
-

src/libs/recommendation/impl/Engine.cpp

@@ -24,6 +24,7 @@
 
 #include "database/ScanSettings.hpp"
 #include "database/TrackList.hpp"
+#include "utils/Exception.hpp"
 #include "utils/Logger.hpp"
 
 namespace Recommendation {
@@ -56,6 +57,8 @@ Engine::stop()
 	assert(_running);
 	_running = false;
 
+	cancelPendingClassifiers();
+
 	_ioService.stop();
 }
 
@@ -73,32 +76,18 @@ Engine::requestReload()
 std::vector<Database::IdType>
 Engine::getSimilarTracksFromTrackList(Database::Session& session, Database::IdType trackListId, std::size_t maxCount)
 {
-	const std::unordered_set<Database::IdType> trackIds {[&]() -> std::unordered_set<Database::IdType>
-	{
-		auto transaction {session.createSharedTransaction()};
-
-		Database::TrackList::pointer trackList {Database::TrackList::getById(session, trackListId)};
-		if (trackList)
-		{
-			const std::vector<Database::IdType> orderedTrackIds {trackList->getTrackIds()};
-			return std::unordered_set<Database::IdType> {std::cbegin(orderedTrackIds), std::cend(orderedTrackIds)};
-		}
-
-		return {};
-	}()};
-
-	if (trackIds.empty())
-		return {};
-
 	std::shared_lock lock {_classifiersMutex};
 
+	std::vector<Database::IdType> res;
+
 	for (const auto& [priority, classifier] : _classifiers)
 	{
-		if (std::any_of(std::cbegin(trackIds), std::cend(trackIds), [&](Database::IdType trackId) { return classifier->isTrackClassified(trackId); } ))
-			return classifier->getSimilarTracksFromTrackList(session, trackListId, maxCount);
+		res = classifier->getSimilarTracksFromTrackList(session, trackListId, maxCount);
+		if (!res.empty())
+			break;
 	}
 
-	return {};
+	return res;
 }
 
 std::vector<Database::IdType>
@@ -106,13 +95,16 @@ Engine::getSimilarTracks(Database::Session& dbSession, const std::unordered_set<
 {
 	std::shared_lock lock {_classifiersMutex};
 
+	std::vector<Database::IdType> res;
+
 	for (const auto& [priority, classifier] : _classifiers)
 	{
-		if (std::any_of(std::cbegin(trackIds), std::cend(trackIds), [&](Database::IdType trackId) { return classifier->isTrackClassified(trackId); } ))
-			return classifier->getSimilarTracks(dbSession, trackIds, maxCount);
+		res = classifier->getSimilarTracks(dbSession, trackIds, maxCount);
+		if (!res.empty())
+			break;
 	}
 
-	return {};
+	return res;
 }
 
 std::vector<Database::IdType>
@@ -120,13 +112,16 @@ Engine::getSimilarReleases(Database::Session& dbSession, Database::IdType releas
 {
 	std::shared_lock lock {_classifiersMutex};
 
+	std::vector<Database::IdType> res;
+
 	for (const auto& [priority, classifier] : _classifiers)
 	{
-		if (classifier->isReleaseClassified(releaseId))
-			return classifier->getSimilarReleases(dbSession, releaseId, maxCount);
+		res = classifier->getSimilarReleases(dbSession, releaseId, maxCount);
+		if (!res.empty())
+			break;
 	}
 
-	return {};
+	return res;
 }
 
 std::vector<Database::IdType>
@@ -134,13 +129,16 @@ Engine::getSimilarArtists(Database::Session& dbSession, Database::IdType artistI
 {
 	std::shared_lock lock {_classifiersMutex};
 
+	std::vector<Database::IdType> res;
+
 	for (const auto& [priority, classifier] : _classifiers)
 	{
-		if (classifier->isArtistClassified(artistId))
-			return classifier->getSimilarArtists(dbSession, artistId, maxCount);
+		res = classifier->getSimilarArtists(dbSession, artistId, maxCount);
+		if (!res.empty())
+			return res;
 	}
 
-	return {};
+	return res;
 }
 
 void
@@ -159,14 +157,35 @@ Engine::reload()
 
 	std::map<ClassifierPriority, std::unique_ptr<IClassifier>> newClassifiers;
 
+	// TODO RAII this
+	auto addClassifier = [&](ClassifierPriority prio, std::unique_ptr<IClassifier> classifier)
+	{
+		try
+		{
+			addPendingClassifier(*classifier.get());
+			bool res {classifier->init(_dbSession)};
+			removePendingClassifier(*classifier.get());
+
+			if (res)
+				newClassifiers.emplace(prio, std::move(classifier));
+
+			return res;
+		}
+		catch (LmsException& e)
+		{
+			removePendingClassifier(*classifier.get());
+			throw;
+		}
+	};
+
 	switch (engineType)
 	{
 		case ScanSettings::RecommendationEngineType::Features:
-//			newClassifiers.emplace_back(0, createFeaturesClassifier()); // higher priority
-//			[[fallthrough]];
+			addClassifier(0, createFeaturesClassifier()); // higher priority
+			[[fallthrough]];
 
 		case ScanSettings::RecommendationEngineType::Clusters:
-			newClassifiers.emplace(1, createClustersClassifier(_dbSession)); // lower priority
+			addClassifier(1, createClustersClassifier()); // lower priority
 			break;
 	}
 
@@ -180,19 +199,29 @@ Engine::reload()
 	_sigReloaded.emit();
 }
 
-
 void
-Engine::clearClassifiers()
+Engine::cancelPendingClassifiers()
 {
+	std::unique_lock<std::shared_mutex> lock {_classifiersMutex};
+	
+	for (IClassifier* classifier : _pendingClassifiers)
+		classifier->requestCancelInit();
 }
 
 void
-Engine::addClassifier(std::unique_ptr<IClassifier> classifier, unsigned priority)
+Engine::addPendingClassifier(IClassifier& classifier)
 {
-	std::unique_lock lock {_classifiersMutex};
+	std::unique_lock<std::shared_mutex> lock {_classifiersMutex};
 
-	_classifiers.emplace(priority, std::move(classifier));
+	_pendingClassifiers.insert(&classifier);
 }
 
+void
+Engine::removePendingClassifier(IClassifier& classifier)
+{
+	std::unique_lock<std::shared_mutex> lock {_classifiersMutex};
+
+	_pendingClassifiers.erase(&classifier);
+}
 
 } // ns Similarity

src/libs/recommendation/impl/Engine.hpp

@@ -52,8 +52,9 @@ namespace Recommendation
 
 
 			void reload();
-			void clearClassifiers();
-			void addClassifier(std::unique_ptr<IClassifier> classifier, unsigned priority);
+			void cancelPendingClassifiers();
+			void addPendingClassifier(IClassifier& classifier);
+			void removePendingClassifier(IClassifier& classifier);
 
 			bool			_running {};
 			Wt::WIOService		_ioService;
@@ -62,6 +63,7 @@ namespace Recommendation
 
 			std::shared_mutex	_classifiersMutex;
 			std::map<ClassifierPriority, std::unique_ptr<IClassifier>> _classifiers;
+			std::unordered_set<IClassifier*> _pendingClassifiers;
 	};
 
 } // ns Recommendation

src/libs/recommendation/impl/clusters/ClustersClassifier.cpp

@@ -28,56 +28,11 @@
 
 namespace Recommendation {
 	
-std::unique_ptr<IClassifier> createClustersClassifier(Database::Session& session)
+std::unique_ptr<IClassifier> createClustersClassifier()
 {
-	return std::make_unique<ClusterClassifier>(session);
+	return std::make_unique<ClusterClassifier>();
 }
 
-ClusterClassifier::ClusterClassifier(Database::Session& session)
-{
-	classify(session);
-}
-
-void
-ClusterClassifier::classify(Database::Session& session)
-{
-	auto transaction {session.createSharedTransaction()};
-
-	{
-		std::vector<Database::IdType> trackIds {Database::Track::getAllIdsWithClusters(session)};
-		_classifiedTracks = std::unordered_set<Database::IdType>(std::cbegin(trackIds), std::cend(trackIds));
-	}
-
-	{
-		std::vector<Database::IdType> releaseIds {Database::Release::getAllIdsWithClusters(session)};
-		_classifiedReleases = std::unordered_set<Database::IdType>(std::cbegin(releaseIds), std::cend(releaseIds));
-	}
-
-	{
-		std::vector<Database::IdType> artistIds {Database::Artist::getAllIdsWithClusters(session)};
-		_classifiedArtists = std::unordered_set<Database::IdType>(std::cbegin(artistIds), std::cend(artistIds));
-	}
-}
-
-bool
-ClusterClassifier::isTrackClassified(Database::IdType trackId) const
-{
-	return _classifiedTracks.find(trackId) != std::cend(_classifiedTracks);
-}
-
-bool
-ClusterClassifier::isReleaseClassified(Database::IdType releaseId) const
-{
-	return _classifiedReleases.find(releaseId) != std::cend(_classifiedReleases);
-}
-
-bool
-ClusterClassifier::isArtistClassified(Database::IdType artistId) const
-{
-	return _classifiedArtists.find(artistId) != std::cend(_classifiedArtists);
-}
-
-
 std::vector<Database::IdType>
 ClusterClassifier::getSimilarTracks(Database::Session& dbSession, const std::unordered_set<Database::IdType>& trackIds, std::size_t maxCount) const
 {

src/libs/recommendation/impl/clusters/ClustersClassifier.hpp

@@ -28,7 +28,7 @@ namespace Recommendation
 	class ClusterClassifier : public IClassifier
 	{
 		public:
-			ClusterClassifier(Database::Session& session);
+			ClusterClassifier() = default;
 			ClusterClassifier(const ClusterClassifier&) = delete;
 			ClusterClassifier(ClusterClassifier&&) = delete;
 			ClusterClassifier& operator=(const ClusterClassifier&) = delete;
@@ -36,20 +36,16 @@ namespace Recommendation
 
 		private:
 
-			bool isTrackClassified(Database::IdType trackId) const override;
-			bool isReleaseClassified(Database::IdType releaseId) const override;
-			bool isArtistClassified(Database::IdType artistId) const override;
+			std::string_view getName() const { return "Clusters"; }
+
+			bool init(Database::Session&) override {return true;}
+			void requestCancelInit() override {}
 
 			std::vector<Database::IdType> getSimilarTracksFromTrackList(Database::Session& session, Database::IdType tracklistId, std::size_t maxCount) const override;
 			std::vector<Database::IdType> getSimilarTracks(Database::Session& session, const std::unordered_set<Database::IdType>& tracksId, std::size_t maxCount) const override;
 			std::vector<Database::IdType> getSimilarReleases(Database::Session& session, Database::IdType releaseId, std::size_t maxCount) const override;
 			std::vector<Database::IdType> getSimilarArtists(Database::Session& session, Database::IdType artistId, std::size_t maxCount) const override;
 
-			void classify(Database::Session& session);
-
-			std::unordered_set<Database::IdType>	_classifiedArtists;
-			std::unordered_set<Database::IdType>	_classifiedReleases;
-			std::unordered_set<Database::IdType>	_classifiedTracks;
 };
 
 } // namespace Recommendation

src/libs/recommendation/impl/features/FeaturesClassifier.cpp

@@ -0,0 +1,445 @@
+/*
+ * Copyright (C) 2018 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "FeaturesClassifier.hpp"
+
+#include <numeric>
+
+#include "database/Artist.hpp"
+#include "database/Release.hpp"
+#include "database/Session.hpp"
+#include "database/Track.hpp"
+#include "database/TrackFeatures.hpp"
+#include "database/TrackList.hpp"
+#include "som/DataNormalizer.hpp"
+#include "utils/Logger.hpp"
+#include "utils/Random.hpp"
+
+
+namespace Recommendation {
+
+std::unique_ptr<IClassifier> createFeaturesClassifier()
+{
+	return std::make_unique<FeaturesClassifier>();
+}
+
+const FeatureSettingsMap&
+FeaturesClassifier::getDefaultTrainFeatureSettings()
+{
+	static const FeatureSettingsMap defaultTrainFeatureSettings
+	{
+		{ "lowlevel.spectral_energyband_high.mean",	{1}},
+		{ "lowlevel.spectral_rolloff.median",		{1}},
+		{ "lowlevel.spectral_contrast_valleys.var",	{1}},
+		{ "lowlevel.erbbands.mean",			{1}},
+		{ "lowlevel.gfcc.mean",				{1}},
+	};
+
+	return defaultTrainFeatureSettings;
+}
+
+static
+std::optional<FeatureValuesMap>
+getTrackFeatureValues(FeaturesClassifier::FeaturesFetchFunc func, Database::IdType trackId, const std::unordered_set<FeatureName>& featureNames)
+{
+	return func(trackId, featureNames);
+}
+
+static
+std::optional<FeatureValuesMap>
+getTrackFeatureValuesFromDb(Database::Session& session, Database::IdType trackId, const std::unordered_set<FeatureName>& featureNames)
+{
+	auto func = [&](Database::IdType trackId, const std::unordered_set<FeatureName>& featureNames)
+	{
+		std::optional<FeatureValuesMap> res;
+
+		auto transaction {session.createSharedTransaction()};
+
+		Database::Track::pointer track {Database::Track::getById(session, trackId)};
+		if (!track)
+			return res;
+
+		res = track->getTrackFeatures()->getFeatureValuesMap(featureNames);
+		if (res->empty())
+			res.reset();
+
+		return res;
+	};
+
+	return getTrackFeatureValues(func, trackId, featureNames);
+}
+
+static
+std::optional<SOM::InputVector>
+convertFeatureValuesMapToInputVector(const FeatureValuesMap& featureValuesMap, std::size_t nbDimensions)
+{
+	std::size_t i {};
+	std::optional<SOM::InputVector> res {SOM::InputVector {nbDimensions}};
+	for (const auto& [featureName, values] : featureValuesMap)
+	{
+		if (values.size() != getFeatureDef(featureName).nbDimensions)
+		{
+			LMS_LOG(RECOMMENDATION, WARNING) << "Dimension mismatch for feature '" << featureName << "'. Expected " << getFeatureDef(featureName).nbDimensions << ", got " << values.size();
+			res.reset();
+			break;
+		}
+
+		for (double val : values)
+			(*res)[i++] = val;
+	}
+
+	return res;
+}
+
+static
+SOM::InputVector
+getInputVectorWeights(const FeatureSettingsMap& featureSettingsMap, std::size_t nbDimensions)
+{
+	SOM::InputVector weights {nbDimensions};
+	std::size_t index {};
+	for (const auto& [featureName, featureSettings] : featureSettingsMap)
+	{
+		const std::size_t featureNbDimensions {getFeatureDef(featureName).nbDimensions};
+
+		for (std::size_t i {}; i < featureNbDimensions; ++i)
+			weights[index++] = (1. / featureNbDimensions * featureSettings.weight);
+	}
+
+	assert(index == nbDimensions);
+
+	return weights;
+}
+
+bool
+FeaturesClassifier::initFromTraining(Database::Session& session, const TrainSettings& trainSettings)
+{
+	LMS_LOG(RECOMMENDATION, INFO) << "Constructing features classifier...";
+
+	std::unordered_set<FeatureName> featureNames;
+	std::transform(std::cbegin(trainSettings.featureSettingsMap), std::cend(trainSettings.featureSettingsMap), std::inserter(featureNames, std::begin(featureNames)),
+		[](const auto& itFeatureSetting) { return itFeatureSetting.first; });
+
+	const std::size_t nbDimensions {std::accumulate(std::cbegin(featureNames), std::cend(featureNames), std::size_t {0},
+			[](std::size_t sum, const FeatureName& featureName) { return sum + getFeatureDef(featureName).nbDimensions; })};
+
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Features dimension = " << nbDimensions;
+
+	std::vector<Database::IdType> trackIds;
+	{
+		auto transaction {session.createSharedTransaction()};
+
+		LMS_LOG(RECOMMENDATION, DEBUG) << "Getting Tracks with features...";
+		trackIds = Database::Track::getAllIdsWithFeatures(session);
+		LMS_LOG(RECOMMENDATION, DEBUG) << "Getting Tracks with features DONE (found " << trackIds.size() << " tracks)";
+	}
+
+	std::vector<SOM::InputVector> samples;
+	std::vector<Database::IdType> samplesTrackIds;
+
+	samples.reserve(trackIds.size());
+	samplesTrackIds.reserve(trackIds.size());
+
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Extracting features...";
+	for (Database::IdType trackId : trackIds)
+	{
+		if (_initCancelled)
+			return false;
+
+		std::optional<FeatureValuesMap> featureValuesMap;
+
+		if (_featuresFetchFunc)
+			featureValuesMap = getTrackFeatureValues(_featuresFetchFunc, trackId, featureNames);
+		else
+			featureValuesMap = getTrackFeatureValuesFromDb(session, trackId, featureNames);
+
+		if (!featureValuesMap)
+			continue;
+
+		std::optional<SOM::InputVector> inputVector {convertFeatureValuesMapToInputVector(*featureValuesMap, nbDimensions)};
+		if (!inputVector)
+			continue;
+
+		samples.emplace_back(std::move(*inputVector));
+		samplesTrackIds.emplace_back(trackId);
+	}
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Extracting features DONE";
+
+	if (samples.empty())
+	{
+		LMS_LOG(RECOMMENDATION, INFO) << "Nothing to classify!";
+		return false;
+	}
+
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Normalizing data...";
+	SOM::DataNormalizer dataNormalizer {nbDimensions};
+
+	dataNormalizer.computeNormalizationFactors(samples);
+	for (auto& sample : samples)
+		dataNormalizer.normalizeData(sample);
+
+	const SOM::Coordinate size {static_cast<SOM::Coordinate>(std::sqrt(samples.size() / trainSettings.sampleCountPerNeuron))};
+	LMS_LOG(RECOMMENDATION, INFO) << "Found " << samples.size() << " tracks, constructing a " << size << "*" << size << " network";
+
+	SOM::Network network {size, size, nbDimensions};
+
+	SOM::InputVector weights {getInputVectorWeights(trainSettings.featureSettingsMap, nbDimensions)};
+	network.setDataWeights(weights);
+
+	auto progressIndicator{[](const auto& iter)
+		{
+			LMS_LOG(RECOMMENDATION, DEBUG) << "Current pass = " << iter.idIteration << " / " << iter.iterationCount;
+		}};
+
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Training network...";
+	network.train(samples, trainSettings.iterationCount, progressIndicator);
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Training network DONE";
+
+	if (_initCancelled)
+		return false;
+
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Classifying tracks...";
+	ObjectPositions trackPositions;
+	for (std::size_t i {}; i < samples.size(); ++i)
+	{
+		if (_initCancelled)
+			return false;
+
+		const SOM::Position position {network.getClosestRefVectorPosition(samples[i])};
+
+		trackPositions[samplesTrackIds[i]].insert(position);
+	}
+
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Classifying tracks DONE";
+
+	return init(session, std::move(network), std::move(trackPositions));
+}
+
+bool
+FeaturesClassifier::initFromCache(Database::Session& session, const FeaturesClassifierCache& cache)
+{
+	LMS_LOG(RECOMMENDATION, INFO) << "Constructing features classifier from cache...";
+
+	return init(session, std::move(cache._network), cache._trackPositions);
+}
+
+std::vector<Database::IdType>
+FeaturesClassifier::getSimilarTracksFromTrackList(Database::Session& session, Database::IdType trackListId, std::size_t maxCount) const
+{
+	const std::unordered_set<Database::IdType> trackIds {[&]() -> std::unordered_set<Database::IdType>
+	{
+		auto transaction {session.createSharedTransaction()};
+
+		const Database::TrackList::pointer trackList {Database::TrackList::getById(session, trackListId)};
+		if (trackList)
+		{
+			const std::vector<Database::IdType> orderedTrackIds {trackList->getTrackIds()};
+			return std::unordered_set<Database::IdType> {std::cbegin(orderedTrackIds), std::cend(orderedTrackIds)};
+		}
+
+		return {};
+	}()};
+
+	return getSimilarTracks(session, trackIds, maxCount);
+}
+
+std::vector<Database::IdType>
+FeaturesClassifier::getSimilarTracks(Database::Session&, const std::unordered_set<Database::IdType>& tracksIds, std::size_t maxCount) const
+{
+	return getSimilarObjects(tracksIds, _tracksMap, _trackPositions, maxCount);
+}
+
+std::vector<Database::IdType>
+FeaturesClassifier::getSimilarReleases(Database::Session&, Database::IdType releaseId, std::size_t maxCount) const
+{
+	return getSimilarObjects({releaseId}, _releasesMap, _releasePositions, maxCount);
+}
+
+std::vector<Database::IdType>
+FeaturesClassifier::getSimilarArtists(Database::Session&, Database::IdType artistId, std::size_t maxCount) const
+{
+	return getSimilarObjects({artistId}, _artistsMap, _artistPositions, maxCount);
+}
+
+FeaturesClassifierCache
+FeaturesClassifier::toCache() const
+{
+	return FeaturesClassifierCache {*_network, _trackPositions};
+}
+
+bool
+FeaturesClassifier::init(Database::Session& session)
+{
+	std::optional<FeaturesClassifierCache> cache {FeaturesClassifierCache::read()};
+	if (cache)
+		return initFromCache(session, *cache);
+
+	TrainSettings trainSettings;
+	trainSettings.featureSettingsMap = getDefaultTrainFeatureSettings();
+
+	bool res {initFromTraining(session, trainSettings)};
+	if (res)
+		toCache().write();
+
+	return res;
+}
+
+void
+FeaturesClassifier::requestCancelInit()
+{
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Requesting init cancellation";
+	_initCancelled = true;
+}
+
+bool
+FeaturesClassifier::init(Database::Session& session,
+			SOM::Network network,
+			const ObjectPositions& tracksPosition)
+{
+	_networkRefVectorsDistanceMedian = network.computeRefVectorsDistanceMedian();
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Median distance betweend ref vectors = " << _networkRefVectorsDistanceMedian;
+
+	const SOM::Coordinate width {network.getWidth()};
+	const SOM::Coordinate height {network.getHeight()};
+
+	_artistsMap = MatrixOfObjects {width, height};
+	_releasesMap = MatrixOfObjects {width, height};
+	_tracksMap = MatrixOfObjects {width, height};
+
+	LMS_LOG(RECOMMENDATION, DEBUG) << "Constructing maps...";
+
+	for (auto itTrackCoord : tracksPosition)
+	{
+		if (_initCancelled)
+			return false;
+
+		auto transaction {session.createSharedTransaction()};
+
+		Database::IdType trackId {itTrackCoord.first};
+		const std::unordered_set<SOM::Position>& positionSet {itTrackCoord.second};
+
+		const Database::Track::pointer track {Database::Track::getById(session, trackId)};
+		if (!track)
+			continue;
+
+		for (const SOM::Position& position : positionSet)
+		{
+			_tracksMap[position].insert(trackId);
+			_trackPositions[trackId].insert(position);
+
+			if (track->getRelease())
+			{
+				_releasePositions[track->getRelease().id()].insert(position);
+				_releasesMap[position].insert(track->getRelease().id());
+			}
+			for (const auto& artist : track->getArtists())
+			{
+				_artistPositions[artist.id()].insert(position);
+				_artistsMap[position].insert(artist.id());
+			}
+		}
+	}
+
+	_network = std::make_unique<SOM::Network>(std::move(network));
+
+	LMS_LOG(RECOMMENDATION, INFO) << "Classifier successfully initialized!";
+
+	return true;
+}
+
+std::unordered_set<SOM::Position>
+FeaturesClassifier::getMatchingRefVectorsPosition(const std::unordered_set<Database::IdType>& ids, const ObjectPositions& objectPositions)
+{
+	std::unordered_set<SOM::Position> res;
+
+	if (ids.empty())
+		return res;
+
+	for (auto id : ids)
+	{
+		auto it = objectPositions.find(id);
+		if (it == objectPositions.end())
+			continue;
+
+		for (const auto& position : it->second)
+			res.insert(position);
+	}
+
+	return res;
+}
+
+std::unordered_set<Database::IdType>
+FeaturesClassifier::getObjectsIds(const std::unordered_set<SOM::Position>& positionSet, const MatrixOfObjects& objectsMap)
+{
+	std::unordered_set<Database::IdType> res;
+
+	for (const auto& position : positionSet)
+	{
+		for (auto id : objectsMap.get(position))
+			res.insert(id);
+	}
+
+	return res;
+}
+
+std::vector<Database::IdType>
+FeaturesClassifier::getSimilarObjects(const std::unordered_set<Database::IdType>& ids,
+		const MatrixOfObjects& objectsMap,
+		const ObjectPositions& objectPosition,
+		std::size_t maxCount) const
+{
+	std::vector<Database::IdType> res;
+
+	std::unordered_set<SOM::Position> searchedRefVectorsPosition {getMatchingRefVectorsPosition(ids, objectPosition)};
+	if (searchedRefVectorsPosition.empty())
+		return res;
+
+	while (1)
+	{
+		std::unordered_set<Database::IdType> closestObjectIds {getObjectsIds(searchedRefVectorsPosition, objectsMap)};
+
+		// Remove objects that are already in input or already reported
+		for (auto id : ids)
+			closestObjectIds.erase(id);
+
+		{
+			std::vector<Database::IdType> objectIdsToAdd {std::cbegin(closestObjectIds), std::cend(closestObjectIds)};
+			Random::shuffleContainer(objectIdsToAdd );
+			std::copy(std::cbegin(objectIdsToAdd), std::cend(objectIdsToAdd), std::back_inserter(res));
+		}
+
+		if (res.size() > maxCount)
+			res.resize(maxCount);
+
+		if (res.size() == maxCount)
+			break;
+
+		// If there is not enough objects, try again with closest neighbour until there is too much distance
+		const std::optional<SOM::Position> closestRefVectorPosition {_network->getClosestRefVectorPosition(searchedRefVectorsPosition, _networkRefVectorsDistanceMedian * 0.75)};
+		if (!closestRefVectorPosition)
+			break;
+
+		searchedRefVectorsPosition.insert(closestRefVectorPosition.value());
+	}
+
+	return res;
+}
+
+
+
+} // ns Recommendation

src/libs/recommendation/impl/features/FeaturesClassifier.hpp

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2018 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <unordered_map>
+#include <optional>
+#include <string>
+
+#include "recommendation/IClassifier.hpp"
+#include "som/DataNormalizer.hpp"
+#include "som/Network.hpp"
+#include "FeaturesClassifierCache.hpp"
+#include "FeaturesDefs.hpp"
+
+namespace Database
+{
+	class Session;
+}
+
+namespace Recommendation {
+
+using FeatureWeight = double;
+
+class FeaturesClassifier : public IClassifier
+{
+	public:
+		FeaturesClassifier() = default;
+		FeaturesClassifier(const FeaturesClassifier&) = delete;
+		FeaturesClassifier(FeaturesClassifier&&) = delete;
+		FeaturesClassifier& operator=(const FeaturesClassifier&) = delete;
+		FeaturesClassifier& operator=(FeaturesClassifier&&) = delete;
+
+		using FeaturesFetchFunc = std::function<std::optional<std::unordered_map<std::string, std::vector<double>>>(Database::IdType /*trackId*/, const std::unordered_set<std::string>& /*features*/)>;
+		// Default is to retrieve the features from the database (may be slow).
+		// Use this only if you want to train different searchers with some cached data
+		static void setFeaturesFetchFunc(FeaturesFetchFunc func) { _featuresFetchFunc = func; }
+
+		static const FeatureSettingsMap& getDefaultTrainFeatureSettings();
+	private:
+
+		std::string_view getName() const { return "Features"; }
+
+		bool init(Database::Session& session) override;
+		void requestCancelInit() override;
+
+		std::vector<Database::IdType> getSimilarTracksFromTrackList(Database::Session& session, Database::IdType tracklistId, std::size_t maxCount) const override;
+		std::vector<Database::IdType> getSimilarTracks(Database::Session& session, const std::unordered_set<Database::IdType>& tracksId, std::size_t maxCount) const override;
+		std::vector<Database::IdType> getSimilarReleases(Database::Session& session, Database::IdType releaseId, std::size_t maxCount) const;
+		std::vector<Database::IdType> getSimilarArtists(Database::Session& session, Database::IdType artistId, std::size_t maxCount) const;
+
+		bool initFromCache(Database::Session& session, const FeaturesClassifierCache& cache);
+
+		// Use training (may be very slow)
+		struct TrainSettings
+		{
+			std::size_t iterationCount {10};
+			float sampleCountPerNeuron {4};
+			FeatureSettingsMap featureSettingsMap;
+		};
+		bool initFromTraining(Database::Session& session, const TrainSettings& trainSettings);
+
+		using ObjectPositions = std::unordered_map<Database::IdType, std::unordered_set<SOM::Position>>;
+		using MatrixOfObjects = SOM::Matrix<std::unordered_set<Database::IdType>>;
+
+		bool init(Database::Session& session,
+				SOM::Network network,
+				const ObjectPositions& tracksPosition);
+
+		FeaturesClassifierCache toCache() const;
+
+		static std::unordered_set<SOM::Position> getMatchingRefVectorsPosition(const std::unordered_set<Database::IdType>& ids, const ObjectPositions& objectPositions);
+		static std::unordered_set<Database::IdType> getObjectsIds(const std::unordered_set<SOM::Position>& positionSet, const MatrixOfObjects& objectsMap);
+
+		std::vector<Database::IdType> getSimilarObjects(const std::unordered_set<Database::IdType>& ids,
+				const SOM::Matrix<std::unordered_set<Database::IdType>>& objectsMap,
+				const ObjectPositions& objectPosition,
+				std::size_t maxCount) const;
+
+		bool				_initCancelled {};
+		std::unique_ptr<SOM::Network>	_network;
+		double				_networkRefVectorsDistanceMedian {};
+
+		MatrixOfObjects		_artistsMap;
+		ObjectPositions		_artistPositions;
+
+		MatrixOfObjects		_releasesMap;
+		ObjectPositions		_releasePositions;
+
+		MatrixOfObjects		_tracksMap;
+		ObjectPositions		_trackPositions;
+
+		static inline FeaturesFetchFunc _featuresFetchFunc;
+};
+
+} // ns Recommendation

src/libs/recommendation/impl/features/FeaturesClassifierCache.cpp

@@ -17,7 +17,7 @@
  * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "SimilarityFeaturesCache.hpp"
+#include "FeaturesClassifierCache.hpp"
 
 #include <boost/property_tree/ptree.hpp>
 #include <boost/property_tree/xml_parser.hpp>
@@ -26,7 +26,7 @@
 #include "utils/Logger.hpp"
 #include "utils/Service.hpp"
 
-namespace Similarity {
+namespace Recommendation {
 
 
 static
@@ -38,7 +38,7 @@ std::filesystem::path getCacheDirectory()
 static std::filesystem::path getCacheNetworkFilePath()
 {
 	return getCacheDirectory() / "network";
-};
+}
 
 static std::filesystem::path getCacheTrackPositionsFilePath()
 {
@@ -79,26 +79,25 @@ networkToCacheFile(const SOM::Network& network, std::filesystem::path path)
 
 		boost::property_tree::write_xml(path.string(), root);
 
-		LMS_LOG(SIMILARITY, DEBUG) << "Created network cache";
+		LMS_LOG(RECOMMENDATION, DEBUG) << "Created network cache";
 		return true;
 	}
 	catch (boost::property_tree::ptree_error& error)
 	{
-		LMS_LOG(SIMILARITY, ERROR) << "Cannot create network cache: " << error.what();
+		LMS_LOG(RECOMMENDATION, ERROR) << "Cannot create network cache: " << error.what();
 		return false;
 	}
 }
 
-static
 std::optional<SOM::Network>
-createNetworkFromCacheFile(const std::filesystem::path& path)
+FeaturesClassifierCache::createNetworkFromCacheFile(const std::filesystem::path& path)
 {
 	if (!std::filesystem::exists(path))
 		return std::nullopt;
 
 	try
 	{
-		LMS_LOG(SIMILARITY, INFO) << "Reading network from cache...";
+		LMS_LOG(RECOMMENDATION, INFO) << "Reading network from cache...";
 
 		boost::property_tree::ptree root;
 
@@ -132,20 +131,19 @@ createNetworkFromCacheFile(const std::filesystem::path& path)
 			res.setRefVector({x, y}, refVector);
 		}
 
-		LMS_LOG(SIMILARITY, INFO) << "Successfully read network from cache";
+		LMS_LOG(RECOMMENDATION, INFO) << "Successfully read network from cache";
 
 		return res;
 	}
 	catch (boost::property_tree::ptree_error& error)
 	{
-		LMS_LOG(SIMILARITY, ERROR) << "Cannot read network cache: " << error.what();
+		LMS_LOG(RECOMMENDATION, ERROR) << "Cannot read network cache: " << error.what();
 		return std::nullopt;
 	}
 }
 
-static
 bool
-objectPositionToCacheFile(const std::map<Database::IdType, std::set<SOM::Position>>& objectsPosition, std::filesystem::path path)
+FeaturesClassifierCache::objectPositionToCacheFile(const ObjectPositions& objectsPosition, const std::filesystem::path& path)
 {
 	try
 	{
@@ -174,24 +172,23 @@ objectPositionToCacheFile(const std::map<Database::IdType, std::set<SOM::Positio
 	}
 	catch (boost::property_tree::ptree_error& error)
 	{
-		LMS_LOG(SIMILARITY, ERROR) << "Cannot cache object position: " << error.what();
+		LMS_LOG(RECOMMENDATION, ERROR) << "Cannot cache object position: " << error.what();
 		return false;
 	}
 }
 
-static
-std::optional<std::map<Database::IdType, std::set<SOM::Position>>>
-createObjectPositionsFromCacheFile(std::filesystem::path path)
+std::optional<FeaturesClassifierCache::ObjectPositions>
+FeaturesClassifierCache::createObjectPositionsFromCacheFile(const std::filesystem::path& path)
 {
 	try
 	{
-		LMS_LOG(SIMILARITY, INFO) << "Reading object position from cache...";
+		LMS_LOG(RECOMMENDATION, INFO) << "Reading object position from cache...";
 
 		boost::property_tree::ptree root;
 
 		boost::property_tree::read_xml(path.string(), root);
 
-		std::map<Database::IdType, std::set<SOM::Position>> res;
+		ObjectPositions res;
 
 		for (const auto& object : root.get_child("objects"))
 		{
@@ -205,42 +202,40 @@ createObjectPositionsFromCacheFile(std::filesystem::path path)
 			}
 		}
 
-		LMS_LOG(SIMILARITY, INFO) << "Successfully read object position from cache";
+		LMS_LOG(RECOMMENDATION, INFO) << "Successfully read object position from cache";
 
 		return res;
 	}
 	catch (boost::property_tree::ptree_error& error)
 	{
-		LMS_LOG(SIMILARITY, ERROR) << "Cannot create object position from cache file: " << error.what();
+		LMS_LOG(RECOMMENDATION, ERROR) << "Cannot create object position from cache file: " << error.what();
 		return std::nullopt;
 	}
 }
 
 void
-FeaturesCache::invalidate()
+FeaturesClassifierCache::invalidate()
 {
 	std::filesystem::remove(getCacheNetworkFilePath());
 	std::filesystem::remove(getCacheTrackPositionsFilePath());
 }
 
-std::optional<FeaturesCache>
-FeaturesCache::read()
+std::optional<FeaturesClassifierCache>
+FeaturesClassifierCache::read()
 {
-	std::optional<FeaturesCache> res;
-
 	auto network{createNetworkFromCacheFile(getCacheNetworkFilePath())};
 	if (!network)
-		return res;
+		return std::nullopt;
 
 	auto trackPositions{createObjectPositionsFromCacheFile(getCacheTrackPositionsFilePath())};
 	if (!trackPositions)
-		return res;
+		return std::nullopt;
 
-	return FeaturesCache{std::move(*network), std::move(*trackPositions)};
+	return FeaturesClassifierCache {std::move(*network), std::move(*trackPositions)};
 }
 
 void
-FeaturesCache::write()
+FeaturesClassifierCache::write() const
 {
 	std::filesystem::create_directories(ServiceProvider<IConfig>::get()->getPath("working-dir") / "cache" / "features");
 
@@ -251,11 +246,10 @@ FeaturesCache::write()
 	}
 }
 
-FeaturesCache::FeaturesCache(SOM::Network network, ObjectPositions trackPositions)
+FeaturesClassifierCache::FeaturesClassifierCache(SOM::Network network, ObjectPositions trackPositions)
 : _network {std::move(network)},
 _trackPositions {std::move(trackPositions)}
 {
 }
 
-
-} // namespace Similarity
+} // namespace Recommendation

src/libs/recommendation/impl/features/FeaturesClassifierCache.hpp

@@ -19,33 +19,36 @@
 
 #pragma once
 
-#include <map>
-#include <optional>
-#include <set>
+#include <filesystem>
+#include <unordered_map>
+#include <unordered_set>
 
 #include "database/Types.hpp"
 #include "som/Network.hpp"
 
-namespace Similarity {
+namespace Recommendation {
 
-class FeaturesCache
+class FeaturesClassifierCache
 {
 	public:
-
 		static void invalidate();
 
-		static std::optional<FeaturesCache> read();
-		void write();
+		static std::optional<FeaturesClassifierCache> read();
+		void write() const;
 
 	private:
-		using ObjectPositions = std::map<Database::IdType, std::set<SOM::Position>>;
+		using ObjectPositions = std::unordered_map<Database::IdType, std::unordered_set<SOM::Position>>;
 
-		FeaturesCache(SOM::Network network, ObjectPositions trackPositions);
+		FeaturesClassifierCache(SOM::Network network, ObjectPositions trackPositions);
 
-		friend class FeaturesSearcher;
+		static std::optional<SOM::Network> createNetworkFromCacheFile(const std::filesystem::path& path);
+		static std::optional<ObjectPositions> createObjectPositionsFromCacheFile(const std::filesystem::path& path);
+		static bool objectPositionToCacheFile(const ObjectPositions& objectsPosition, const std::filesystem::path& path);
+
+		friend class FeaturesClassifier;
 
 		SOM::Network		_network;
 		ObjectPositions		_trackPositions;
 };
 
-} // namespace Similarity
+} // namespace Recommendation

src/libs/recommendation/impl/features/FeaturesDefs.cpp

@@ -17,14 +17,14 @@
  * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "SimilarityFeaturesDefs.hpp"
+#include "FeaturesDefs.hpp"
 
 #include <algorithm>
 #include <iterator>
 
 #include "utils/Exception.hpp"
 
-namespace Similarity {
+namespace Recommendation {
 
 static const std::unordered_map<FeatureName, FeatureDef> featureDefinitions
 {
@@ -398,5 +398,5 @@ getFeatureNames()
 	return res;
 }
 
-} // namespace Similarity
+} // namespace Recommendation
 

src/libs/recommendation/impl/features/FeaturesDefs.hpp

@@ -24,7 +24,7 @@
 #include <unordered_set>
 #include <vector>
 
-namespace Similarity {
+namespace Recommendation {
 
 using FeatureName = std::string;
 using FeatureNames = std::unordered_set<FeatureName>;
@@ -46,4 +46,4 @@ struct FeatureSettings
 };
 using FeatureSettingsMap = std::unordered_map<FeatureName, FeatureSettings>;
 
-} // namespace Similarity
+} // namespace Recommendation

src/libs/recommendation/impl/features/SimilarityFeaturesScannerAddon.cpp

@@ -1,187 +0,0 @@
-/*
- * Copyright (C) 2019 Emeric Poupon
- *
- * This file is part of LMS.
- *
- * LMS 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 3 of the License, or
- * (at your option) any later version.
- *
- * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "similarity/features/SimilarityFeaturesScannerAddon.hpp"
-
-#include "AcousticBrainzUtils.hpp"
-#include "database/ScanSettings.hpp"
-#include "database/Track.hpp"
-#include "database/TrackFeatures.hpp"
-#include "utils/Logger.hpp"
-
-#include "SimilarityFeaturesCache.hpp"
-
-namespace Similarity {
-
-static
-bool
-hasAtLeastOneTrackWithFeatures(Database::Session& session)
-{
-	auto transaction {session.createSharedTransaction()};
-	return !Database::Track::getAllIdsWithFeatures(session, 1).empty();
-}
-
-struct TrackInfo
-{
-	Database::IdType id;
-	std::optional<UUID> mbid;
-};
-
-static
-std::vector<TrackInfo>
-getTracksWithMBIDAndMissingFeatures(Database::Session& dbSession)
-{
-	std::vector<TrackInfo> res;
-
-	auto transaction {dbSession.createSharedTransaction()};
-
-	auto tracks {Database::Track::getAllWithMBIDAndMissingFeatures(dbSession)};
-	for (const Database::Track::pointer& track : tracks)
-		res.push_back({track.id(), track->getMBID()});
-
-	return res;
-}
-
-FeaturesScannerAddon::FeaturesScannerAddon(Database::Db& db)
-: _dbSession {db}
-{
-	std::optional<Similarity::FeaturesCache> cache {Similarity::FeaturesCache::read()};
-	if (cache)
-	{
-		auto searcher {std::make_shared<Similarity::FeaturesSearcher>(_dbSession, *cache, [&]() { return _stopRequested; })};
-		if (searcher->isValid())
-			std::atomic_store(&_searcher, searcher);
-	}
-}
-
-std::shared_ptr<Similarity::FeaturesSearcher>
-FeaturesScannerAddon::getSearcher()
-{
-	return std::atomic_load(&_searcher);
-}
-
-void
-FeaturesScannerAddon::requestStop()
-{
-	_stopRequested = true;
-}
-
-void
-FeaturesScannerAddon::trackUpdated(Database::IdType trackId)
-{
-	auto uniqueTransaction {_dbSession.createUniqueTransaction()};
-
-	auto track {Database::Track::getById(_dbSession, trackId)};
-	if (!track)
-		return;
-
-	track.modify()->setFeatures({});
-}
-
-void
-FeaturesScannerAddon::preScanComplete()
-{
-	{
-		auto transaction {_dbSession.createSharedTransaction()};
-
-		if (Database::ScanSettings::get(_dbSession)->getSimilarityEngineType() != Database::ScanSettings::SimilarityEngineType::Features)
-		{
-			LMS_LOG(DBUPDATER, INFO) << "Do not fetch features since the engine type does not make use of them";
-			return;
-		}
-	}
-
-	LMS_LOG(DBUPDATER, DEBUG) << "Getting tracks with missing Features...";
-	const std::vector<TrackInfo> tracksInfo {getTracksWithMBIDAndMissingFeatures(_dbSession)};
-	LMS_LOG(DBUPDATER, DEBUG) << "Getting tracks with missing Features DONE (found " << tracksInfo.size() << ")";
-
-	if (!tracksInfo.empty())
-		Similarity::FeaturesCache::invalidate();
-
-	for (const TrackInfo& trackInfo : tracksInfo)
-	{
-		if (_stopRequested)
-			return;
-
-		if (trackInfo.mbid)
-			fetchFeatures(trackInfo.id, *trackInfo.mbid);
-	}
-
-	updateSearcher();
-}
-
-void
-FeaturesScannerAddon::updateSearcher()
-{
-	LMS_LOG(SIMILARITY, INFO) << "Updating searcher...";
-
-	if (!hasAtLeastOneTrackWithFeatures(_dbSession))
-	{
-		LMS_LOG(DBUPDATER, INFO) << "No track found with features!";
-		std::atomic_store(&_searcher, std::shared_ptr<FeaturesSearcher>{});
-		return;
-	}
-
-	Similarity::FeaturesSearcher::TrainSettings trainSettings;
-	trainSettings.featureSettingsMap = FeaturesSearcher::getDefaultTrainFeatureSettings();
-
-	auto searcher {std::make_shared<FeaturesSearcher>(_dbSession, trainSettings, [&]() { return _stopRequested; })};
-	if (searcher->isValid())
-	{
-		std::atomic_store(&_searcher, searcher);
-		FeaturesCache cache{searcher->toCache()};
-		cache.write();
-
-		LMS_LOG(DBUPDATER, INFO) << "New features similarity searcher instanciated";
-	}
-	else
-	{
-		LMS_LOG(DBUPDATER, ERROR) << "Cannot set up a valid features similarity searcher!";
-		std::atomic_store(&_searcher, std::shared_ptr<FeaturesSearcher>{});
-	}
-}
-
-bool
-FeaturesScannerAddon::fetchFeatures(Database::IdType trackId, const UUID& MBID)
-{
-	std::map<std::string, double> features;
-
-	LMS_LOG(DBUPDATER, DEBUG) << "Fetching low level features for track '" << MBID.getAsString() << "'";
-	const std::string data {AcousticBrainz::extractLowLevelFeatures(MBID)};
-	if (data.empty())
-	{
-		LMS_LOG(DBUPDATER, ERROR) << "Track " << trackId << ", MBID = '" << MBID.getAsString() << "': cannot extract features using AcousticBrainz";
-		return false;
-	}
-
-	{
-		auto uniqueTransaction {_dbSession.createUniqueTransaction()};
-
-		Wt::Dbo::ptr<Database::Track> track {Database::Track::getById(_dbSession, trackId)};
-		if (!track)
-			return false;
-
-		Database::TrackFeatures::create(_dbSession, track, data);
-	}
-
-	return true;
-}
-
-} // namespace Similarity
-

src/libs/recommendation/impl/features/SimilarityFeaturesSearcher.cpp

@@ -1,487 +0,0 @@
-/*
- * Copyright (C) 2018 Emeric Poupon
- *
- * This file is part of LMS.
- *
- * LMS 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 3 of the License, or
- * (at your option) any later version.
- *
- * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "SimilarityFeaturesSearcher.hpp"
-
-#include <random>
-#include <unordered_map>
-
-#include "database/Artist.hpp"
-#include "database/Release.hpp"
-#include "database/Session.hpp"
-#include "database/Track.hpp"
-#include "database/TrackFeatures.hpp"
-#include "som/DataNormalizer.hpp"
-#include "utils/Logger.hpp"
-
-
-namespace Similarity {
-
-const FeatureSettingsMap&
-FeaturesSearcher::getDefaultTrainFeatureSettings()
-{
-	static FeatureSettingsMap defaultTrainFeatureSettings
-	{
-		{ "lowlevel.spectral_energyband_high.mean",	{1}},
-		{ "lowlevel.spectral_rolloff.median",		{1}},
-		{ "lowlevel.spectral_contrast_valleys.var",	{1}},
-		{ "lowlevel.erbbands.mean",			{1}},
-		{ "lowlevel.gfcc.mean",				{1}},
-	};
-
-	return defaultTrainFeatureSettings;
-}
-
-static
-std::optional<FeatureValuesMap>
-getTrackFeatureValues(FeaturesSearcher::FeaturesFetchFunc func, Database::IdType trackId, const std::unordered_set<FeatureName>& featureNames)
-{
-	return func(trackId, featureNames);
-}
-
-static
-std::optional<FeatureValuesMap>
-getTrackFeatureValuesFromDb(Database::Session& session, Database::IdType trackId, const std::unordered_set<FeatureName>& featureNames)
-{
-	auto func = [&](Database::IdType trackId, const std::unordered_set<FeatureName>& featureNames)
-	{
-		std::optional<FeatureValuesMap> res;
-
-		auto transaction {session.createSharedTransaction()};
-
-		Database::Track::pointer track {Database::Track::getById(session, trackId)};
-		if (!track)
-			return res;
-
-		res = track->getTrackFeatures()->getFeatureValuesMap(featureNames);
-		if (res->empty())
-			res.reset();
-
-		return res;
-	};
-
-	return getTrackFeatureValues(func, trackId, featureNames);
-}
-
-static
-std::optional<SOM::InputVector>
-convertFeatureValuesMapToInputVector(const FeatureValuesMap& featureValuesMap, std::size_t nbDimensions)
-{
-	std::size_t i {};
-	std::optional<SOM::InputVector> res {SOM::InputVector {nbDimensions}};
-	for (const auto& [featureName, values] : featureValuesMap)
-	{
-		if (values.size() != getFeatureDef(featureName).nbDimensions)
-		{
-			LMS_LOG(SIMILARITY, WARNING) << "Dimension mismatch for feature '" << featureName << "'. Expected " << getFeatureDef(featureName).nbDimensions << ", got " << values.size();
-			res.reset();
-			break;
-		}
-
-		for (double val : values)
-			(*res)[i++] = val;
-	}
-
-	return res;
-}
-
-static
-SOM::InputVector
-getInputVectorWeights(const FeatureSettingsMap& featureSettingsMap, std::size_t nbDimensions)
-{
-	SOM::InputVector weights {nbDimensions};
-	std::size_t index {};
-	for (const auto& [featureName, featureSettings] : featureSettingsMap)
-	{
-		const std::size_t featureNbDimensions {getFeatureDef(featureName).nbDimensions};
-
-		for (std::size_t i {}; i < featureNbDimensions; ++i)
-			weights[index++] = (1. / featureNbDimensions * featureSettings.weight);
-	}
-
-	assert(index == nbDimensions);
-
-	return weights;
-}
-
-FeaturesSearcher::FeaturesSearcher(Database::Session& session,
-		const TrainSettings& trainSettings,
-		StopRequestedFunction stopRequested)
-{
-	LMS_LOG(SIMILARITY, INFO) << "Constructing features searcher...";
-
-	std::unordered_set<FeatureName> featureNames;
-	std::transform(std::cbegin(trainSettings.featureSettingsMap), std::cend(trainSettings.featureSettingsMap), std::inserter(featureNames, std::begin(featureNames)),
-		[](const auto& itFeatureSetting) { return itFeatureSetting.first; });
-
-	const std::size_t nbDimensions {std::accumulate(std::cbegin(featureNames), std::cend(featureNames), std::size_t {0},
-			[](std::size_t sum, const FeatureName& featureName) { return sum + getFeatureDef(featureName).nbDimensions; })};
-
-	LMS_LOG(SIMILARITY, DEBUG) << "Features dimension = " << nbDimensions;
-
-	std::vector<Database::IdType> trackIds;
-	{
-		auto transaction {session.createSharedTransaction()};
-
-		LMS_LOG(SIMILARITY, DEBUG) << "Getting Tracks with features...";
-		trackIds = Database::Track::getAllIdsWithFeatures(session);
-		LMS_LOG(SIMILARITY, DEBUG) << "Getting Tracks with features DONE (found " << trackIds.size() << " tracks)";
-	}
-
-	std::vector<SOM::InputVector> samples;
-	std::vector<Database::IdType> samplesTrackIds;
-
-	samples.reserve(trackIds.size());
-	samplesTrackIds.reserve(trackIds.size());
-
-	LMS_LOG(SIMILARITY, DEBUG) << "Extracting features...";
-	for (Database::IdType trackId : trackIds)
-	{
-		if (stopRequested && stopRequested())
-			return;
-
-		std::optional<FeatureValuesMap> featureValuesMap;
-
-		if (_featuresFetchFunc)
-			featureValuesMap = getTrackFeatureValues(_featuresFetchFunc, trackId, featureNames);
-		else
-			featureValuesMap = getTrackFeatureValuesFromDb(session, trackId, featureNames);
-
-		if (!featureValuesMap)
-			continue;
-
-		std::optional<SOM::InputVector> inputVector {convertFeatureValuesMapToInputVector(*featureValuesMap, nbDimensions)};
-		if (!inputVector)
-			continue;
-
-		samples.emplace_back(std::move(*inputVector));
-		samplesTrackIds.emplace_back(trackId);
-	}
-	LMS_LOG(SIMILARITY, DEBUG) << "Extracting features DONE";
-
-	if (samples.empty())
-	{
-		LMS_LOG(SIMILARITY, INFO) << "Nothing to classify!";
-		return;
-	}
-
-	LMS_LOG(SIMILARITY, DEBUG) << "Normalizing data...";
-	SOM::DataNormalizer dataNormalizer {nbDimensions};
-
-	dataNormalizer.computeNormalizationFactors(samples);
-	for (auto& sample : samples)
-		dataNormalizer.normalizeData(sample);
-
-	SOM::Coordinate size {static_cast<SOM::Coordinate>(std::sqrt(samples.size() / trainSettings.sampleCountPerNeuron))};
-	LMS_LOG(SIMILARITY, INFO) << "Found " << samples.size() << " tracks, constructing a " << size << "*" << size << " network";
-
-	SOM::Network network {size, size, nbDimensions};
-
-	SOM::InputVector weights {getInputVectorWeights(trainSettings.featureSettingsMap, nbDimensions)};
-	network.setDataWeights(weights);
-
-	auto progressIndicator{[](const auto& iter)
-		{
-			LMS_LOG(SIMILARITY, DEBUG) << "Current pass = " << iter.idIteration << " / " << iter.iterationCount;
-		}};
-
-	LMS_LOG(SIMILARITY, DEBUG) << "Training network...";
-	network.train(samples, trainSettings.iterationCount, progressIndicator, stopRequested);
-	LMS_LOG(SIMILARITY, DEBUG) << "Training network DONE";
-
-	if (stopRequested && stopRequested())
-		return;
-
-	LMS_LOG(SIMILARITY, DEBUG) << "Classifying tracks...";
-	std::map<Database::IdType, std::set<SOM::Position>> trackPositions;
-	for (std::size_t i {}; i < samples.size(); ++i)
-	{
-		if (stopRequested && stopRequested())
-			return;
-
-		const SOM::Position position {network.getClosestRefVectorPosition(samples[i])};
-
-		trackPositions[samplesTrackIds[i]].insert(position);
-	}
-
-	LMS_LOG(SIMILARITY, DEBUG) << "Classifying tracks DONE";
-
-	init(session, std::move(network), std::move(trackPositions), stopRequested);
-
-	LMS_LOG(SIMILARITY, INFO) << "Successfully constructed features searcher";
-}
-
-FeaturesSearcher::FeaturesSearcher(Database::Session& session, FeaturesCache cache, StopRequestedFunction stopRequested)
-{
-	LMS_LOG(SIMILARITY, INFO) << "Constructing features searcher from cache...";
-
-	init(session, std::move(cache._network), std::move(cache._trackPositions), stopRequested);
-
-	LMS_LOG(SIMILARITY, INFO) << "Successfully constructed features searcher from cache";
-}
-
-bool
-FeaturesSearcher::isValid() const
-{
-	return _network.get() != nullptr;
-}
-
-bool
-FeaturesSearcher::isTrackClassified(Database::IdType trackId) const
-{
-	return (_trackPositions.find(trackId) != _trackPositions.end());
-}
-
-bool
-FeaturesSearcher::isReleaseClassified(Database::IdType releaseId) const
-{
-	return (_releasePositions.find(releaseId) != _releasePositions.end());
-}
-
-bool
-FeaturesSearcher::isArtistClassified(Database::IdType artistId) const
-{
-	return (_artistPositions.find(artistId) != _artistPositions.end());
-}
-
-std::vector<Database::IdType>
-FeaturesSearcher::getSimilarTracks(const std::set<Database::IdType>& tracksIds, std::size_t maxCount) const
-{
-	return getSimilarObjects(tracksIds, _tracksMap, _trackPositions, maxCount);
-}
-
-std::vector<Database::IdType>
-FeaturesSearcher::getSimilarReleases(Database::IdType releaseId, std::size_t maxCount) const
-{
-	return getSimilarObjects({releaseId}, _releasesMap, _releasePositions, maxCount);
-}
-
-std::vector<Database::IdType>
-FeaturesSearcher::getSimilarArtists(Database::IdType artistId, std::size_t maxCount) const
-{
-	return getSimilarObjects({artistId}, _artistsMap, _artistPositions, maxCount);
-}
-
-void
-FeaturesSearcher::dump(Database::Session& session, std::ostream& os) const
-{
-	if (!isValid())
-	{
-		os << "Invalid searcher" << std::endl;
-		return;
-	}
-
-	os << "Number of tracks classified: " << _trackPositions.size() << std::endl;
-	os << "Network size: " << _network->getWidth() << " * " << _network->getHeight() << std::endl;
-	os << "Ref vectors median distance = " << _networkRefVectorsDistanceMedian << std::endl;
-
-	auto transaction {session.createSharedTransaction()};
-
-	for (SOM::Coordinate y {}; y < _network->getHeight(); ++y)
-	{
-		for (SOM::Coordinate x {}; x < _network->getWidth(); ++x)
-		{
-			const auto& trackIds {_tracksMap[{x, y}]};
-
-			os << "{" << x << ", " << y << "}";
-
-			if (y > 0)
-				os << " - {" << x << ", " << y - 1 << "}: " << _network->getRefVectorsDistance({x, y}, {x, y - 1});
-			if (x > 0)
-				os << " - {" << x - 1 << ", " << y << "}: " << _network->getRefVectorsDistance({x, y}, {x - 1, y});
-			if (y !=  _network->getHeight() - 1)
-				os << " - {" << x << ", " << y + 1 << "}: " << _network->getRefVectorsDistance({x, y}, {x, y + 1});
-			if (x !=  _network->getWidth() - 1)
-				os << " - {" << x + 1 << ", " << y << "}: " << _network->getRefVectorsDistance({x, y}, {x + 1, y});
-			os << std::endl;
-
-			for (Database::IdType trackId : trackIds)
-			{
-				auto track {Database::Track::getById(session, trackId)};
-				if (!track)
-					continue;
-
-				os << "\t";
-				for (auto artist : track->getArtists())
-					os << artist->getName() << " - ";
-				if (track->getRelease())
-					os << track->getRelease()->getName() << " - ";
-				os << track->getName() << std::endl;
-			}
-
-		}
-		os << std::endl;
-	}
-}
-
-FeaturesCache
-FeaturesSearcher::toCache() const
-{
-	return FeaturesCache{*_network, _trackPositions};
-}
-
-void
-FeaturesSearcher::init(Database::Session& session,
-			SOM::Network network,
-			std::map<Database::IdType,
-			std::set<SOM::Position>> tracksPosition,
-			std::function<bool()> stopRequested)
-{
-	_networkRefVectorsDistanceMedian = network.computeRefVectorsDistanceMedian();
-	LMS_LOG(SIMILARITY, DEBUG) << "Median distance betweend ref vectors = " << _networkRefVectorsDistanceMedian;
-
-	SOM::Coordinate width {network.getWidth()};
-	SOM::Coordinate height {network.getHeight()};
-
-	_artistsMap = SOM::Matrix<std::set<Database::IdType>>{width, height};
-	_releasesMap = SOM::Matrix<std::set<Database::IdType>>{width, height};
-	_tracksMap = SOM::Matrix<std::set<Database::IdType>>{width, height};
-
-	LMS_LOG(SIMILARITY, DEBUG) << "Constructing maps...";
-
-	for (auto itTrackCoord : tracksPosition)
-	{
-		if (stopRequested && stopRequested())
-			return;
-
-		auto transaction {session.createSharedTransaction()};
-
-		Database::IdType trackId {itTrackCoord.first};
-		const std::set<SOM::Position>& positionSet {itTrackCoord.second};
-
-		const Database::Track::pointer track {Database::Track::getById(session, trackId)};
-		if (!track)
-			continue;
-
-		for (const SOM::Position& position : positionSet)
-		{
-			_tracksMap[position].insert(trackId);
-			_trackPositions[trackId].insert(position);
-
-			if (track->getRelease())
-			{
-				_releasePositions[track->getRelease().id()].insert(position);
-				_releasesMap[position].insert(track->getRelease().id());
-			}
-			for (const auto& artist : track->getArtists())
-			{
-				_artistPositions[artist.id()].insert(position);
-				_artistsMap[position].insert(artist.id());
-			}
-		}
-	}
-
-	_network = std::make_unique<SOM::Network>(std::move(network));
-
-	LMS_LOG(SIMILARITY, DEBUG) << "Constructing maps... DONE";
-
-}
-
-static
-std::set<SOM::Position>
-getMatchingRefVectorsPosition(const std::set<Database::IdType>& ids, const std::map<Database::IdType, std::set<SOM::Position>>& objectPosition)
-{
-	std::set<SOM::Position> res;
-
-	if (ids.empty())
-		return res;
-
-	for (auto id : ids)
-	{
-		auto it = objectPosition.find(id);
-		if (it == objectPosition.end())
-			continue;
-
-		for (const auto& position : it->second)
-			res.insert(position);
-	}
-
-	return res;
-}
-
-static
-std::set<Database::IdType>
-getObjectsIds(const std::set<SOM::Position>& positionSet, const SOM::Matrix<std::set<Database::IdType>>& objectsMap )
-{
-	std::set<Database::IdType> res;
-
-	for (const auto& position : positionSet)
-	{
-		for (auto id : objectsMap.get(position))
-			res.insert(id);
-	}
-
-	return res;
-}
-
-std::vector<Database::IdType>
-FeaturesSearcher::getSimilarObjects(const std::set<Database::IdType>& ids,
-		const SOM::Matrix<std::set<Database::IdType>>& objectsMap,
-		const std::map<Database::IdType, std::set<SOM::Position>>& objectPosition,
-		std::size_t maxCount) const
-{
-	std::vector<Database::IdType> res;
-
-	if (!isValid())
-		return res;
-
-	auto now {std::chrono::system_clock::now()};
-	std::mt19937 randGenerator{static_cast<std::mt19937::result_type>(std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count())};
-
-	std::set<SOM::Position> searchedRefVectorsPosition {getMatchingRefVectorsPosition(ids, objectPosition)};
-	if (searchedRefVectorsPosition.empty())
-		return res;
-
-	while (1)
-	{
-		std::set<Database::IdType> closestObjectIds {getObjectsIds(searchedRefVectorsPosition, objectsMap)};
-
-		// Remove objects that are already in input or already reported
-		for (auto id : ids)
-			closestObjectIds.erase(id);
-
-		for (auto id : res)
-			closestObjectIds.erase(id);
-
-		{
-			std::vector<Database::IdType> objectIdsToAdd {closestObjectIds.begin(), closestObjectIds.end()};
-			std::shuffle(objectIdsToAdd.begin(), objectIdsToAdd.end(), randGenerator);
-			std::copy(objectIdsToAdd.begin(), objectIdsToAdd.end(), std::back_inserter(res));
-		}
-
-		if (res.size() > maxCount)
-			res.resize(maxCount);
-
-		if (res.size() == maxCount)
-			break;
-
-		// If there is not enough objects, try again with closest neighbour until there is too much distance
-		std::optional<SOM::Position> closestRefVectorPosition {_network->getClosestRefVectorPosition(searchedRefVectorsPosition, _networkRefVectorsDistanceMedian * 0.75)};
-		if (!closestRefVectorPosition)
-			break;
-
-		searchedRefVectorsPosition.insert(*closestRefVectorPosition);
-	}
-
-	return res;
-}
-
-
-
-} // ns Similarity

src/libs/recommendation/impl/features/SimilarityFeaturesSearcher.hpp

@@ -1,110 +0,0 @@
-/*
- * Copyright (C) 2018 Emeric Poupon
- *
- * This file is part of LMS.
- *
- * LMS 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 3 of the License, or
- * (at your option) any later version.
- *
- * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#pragma once
-
-#include <map>
-#include <optional>
-#include <set>
-#include <string>
-
-#include "database/Types.hpp"
-#include "som/DataNormalizer.hpp"
-#include "som/Network.hpp"
-#include "SimilarityFeaturesCache.hpp"
-#include "SimilarityFeaturesDefs.hpp"
-
-namespace Database
-{
-	class Session;
-}
-
-namespace Similarity {
-
-using FeatureWeight = double;
-
-class FeaturesSearcher
-{
-	public:
-
-		using StopRequestedFunction = std::function<bool()>; // return true if stop requested
-
-		// Use cache
-		FeaturesSearcher(Database::Session& session, FeaturesCache cache, StopRequestedFunction stopRequested);
-
-		// Use training (may be very slow)
-		struct TrainSettings
-		{
-			std::size_t iterationCount {10};
-			float sampleCountPerNeuron {4};
-			FeatureSettingsMap featureSettingsMap;
-		};
-		FeaturesSearcher(Database::Session& session, const TrainSettings& trainSettings, StopRequestedFunction stopRequested = {});
-
-		static const FeatureSettingsMap& getDefaultTrainFeatureSettings();
-
-		bool isValid() const;
-
-		bool isTrackClassified(Database::IdType trackId) const;
-		bool isReleaseClassified(Database::IdType releaseId) const;
-		bool isArtistClassified(Database::IdType artistId) const;
-
-		std::vector<Database::IdType> getSimilarTracks(const std::set<Database::IdType>& tracksId, std::size_t maxCount) const;
-		std::vector<Database::IdType> getSimilarReleases(Database::IdType releaseId, std::size_t maxCount) const;
-		std::vector<Database::IdType> getSimilarArtists(Database::IdType artistId, std::size_t maxCount) const;
-
-		void dump(Database::Session& session, std::ostream& os) const;
-
-		FeaturesCache toCache() const;
-
-		using FeaturesFetchFunc = std::function<std::optional<std::unordered_map<std::string, std::vector<double>>>(Database::IdType /*trackId*/, const std::unordered_set<std::string>& /*features*/)>;
-		// Default is to retrieve the features from the database (may be slow).
-		// Use this only if you want to train different searchers with the same data
-		static void setFeaturesFetchFunc(FeaturesFetchFunc func) { _featuresFetchFunc = func; }
-
-	private:
-
-		using ObjectPositions = std::map<Database::IdType, std::set<SOM::Position>>;
-
-		void init(Database::Session& session,
-				SOM::Network network,
-				ObjectPositions tracksPosition,
-				StopRequestedFunction stopRequested);
-
-		std::vector<Database::IdType> getSimilarObjects(const std::set<Database::IdType>& ids,
-				const SOM::Matrix<std::set<Database::IdType>>& objectsMap,
-				const ObjectPositions& objectPosition,
-				std::size_t maxCount) const;
-
-		std::unique_ptr<SOM::Network>	_network;
-		double				_networkRefVectorsDistanceMedian {};
-
-		SOM::Matrix<std::set<Database::IdType>> 	_artistsMap;
-		ObjectPositions					_artistPositions;
-
-		SOM::Matrix<std::set<Database::IdType>> 	_releasesMap;
-		ObjectPositions					_releasePositions;
-
-		SOM::Matrix<std::set<Database::IdType>> 	_tracksMap;
-		ObjectPositions					_trackPositions;
-
-		static inline FeaturesFetchFunc _featuresFetchFunc;
-};
-
-} // ns Similarity

src/libs/recommendation/include/recommendation/ClustersClassifierCreator.hpp

@@ -25,6 +25,6 @@ namespace Recommendation
 {
 	class IClassifier;
 
-	std::unique_ptr<IClassifier> createClustersClassifier(Database::Session& session);
+	std::unique_ptr<IClassifier> createClustersClassifier();
 }
 

src/libs/recommendation/include/recommendation/FeaturesClassifierCreator.hpp

@@ -20,11 +20,10 @@
 #pragma once
 
 #include <memory>
+#include "recommendation/IClassifier.hpp"
 
 namespace Recommendation
 {
-	class IClassifier;
-
 	std::unique_ptr<IClassifier> createFeaturesClassifier();
 }
 

src/libs/recommendation/include/recommendation/IClassifier.hpp

@@ -19,6 +19,7 @@
 
 #pragma once
 
+#include <functional>
 #include <unordered_set>
 #include <vector>
 
@@ -37,9 +38,10 @@ namespace Recommendation
 		public:
 			virtual ~IClassifier() = default;
 
-			virtual bool isTrackClassified(Database::IdType trackId) const = 0;
-			virtual bool isReleaseClassified(Database::IdType releaseId) const = 0;
-			virtual bool isArtistClassified(Database::IdType artistId) const = 0;
+			virtual std::string_view getName() const = 0;
+
+			virtual bool init(Database::Session& session) = 0;
+			virtual void requestCancelInit() = 0;
 
 			virtual std::vector<Database::IdType> getSimilarTracksFromTrackList(Database::Session& session, Database::IdType tracklistId, std::size_t maxCount) const = 0;
 			virtual std::vector<Database::IdType> getSimilarTracks(Database::Session& session, const std::unordered_set<Database::IdType>& tracksId, std::size_t maxCount) const = 0;

src/libs/scanner/CMakeLists.txt

@@ -1,5 +1,6 @@
 
 add_library(lmsscanner SHARED
+	impl/AcousticBrainzUtils.cpp
 	impl/MediaScanner.cpp
 	impl/MediaScannerStats.cpp
 	)

src/libs/scanner/impl/AcousticBrainzUtils.cpp

@@ -28,6 +28,7 @@
 #include "utils/IConfig.hpp"
 #include "utils/Logger.hpp"
 #include "utils/Service.hpp"
+#include "utils/UUID.hpp"
 
 
 namespace AcousticBrainz
@@ -50,7 +51,7 @@ getJsonData(const UUID& mbid)
 
 	if (!client.get(url))
 	{
-		LMS_LOG(SIMILARITY, ERROR) << "Cannot perform a GET request to url '" << url << "'";
+		LMS_LOG(DBUPDATER, ERROR) << "Cannot perform a GET request to url '" << url << "'";
 		return {};
 	}
 
@@ -59,13 +60,13 @@ getJsonData(const UUID& mbid)
 	{
 		if (ec)
 		{
-			LMS_LOG(SIMILARITY, ERROR) << "GET request to url '" << url << "' failed: " << ec.message();
+			LMS_LOG(DBUPDATER, ERROR) << "GET request to url '" << url << "' failed: " << ec.message();
 			return;
 		}
 
 		if (msg.status() != 200)
 		{
-			LMS_LOG(SIMILARITY, ERROR) << "GET request to url '" << url << "' failed: status = " << msg.status() << ", body = " << msg.body();
+			LMS_LOG(DBUPDATER, ERROR) << "GET request to url '" << url << "' failed: status = " << msg.status() << ", body = " << msg.body();
 			return;
 		}
 

src/libs/scanner/impl/AcousticBrainzUtils.hpp

@@ -21,7 +21,7 @@
 
 #include <string>
 
-#include "utils/UUID.hpp"
+class UUID;
 
 namespace AcousticBrainz
 {

src/libs/scanner/impl/MediaScanner.cpp

@@ -28,10 +28,13 @@
 #include "database/Release.hpp"
 #include "database/ScanSettings.hpp"
 #include "database/Track.hpp"
+#include "database/TrackFeatures.hpp"
 #include "metadata/TagLibParser.hpp"
 #include "utils/Exception.hpp"
 #include "utils/Logger.hpp"
 #include "utils/Path.hpp"
+#include "utils/UUID.hpp"
+#include "AcousticBrainzUtils.hpp"
 
 using namespace Database;
 
@@ -420,7 +423,10 @@ MediaScanner::scan(boost::system::error_code err)
 	if (_running)
 		checkDuplicatedAudioFiles(stats);
 
-	LMS_LOG(DBUPDATER, INFO) << "Scan " << (_running ? "complete" : "aborted") << ". Changes = " << stats.nbChanges() << " (added = " << stats.additions << ", removed = " << stats.deletions << ", updated = " << stats.updates << "), Not changed = " << stats.skips << ", Scanned = " << stats.scans << " (errors = " << stats.errors.size() << "), duplicates = " << stats.duplicates.size();
+	// Now update all the track features if needed
+	fetchTrackFeatures(stats);
+
+	LMS_LOG(DBUPDATER, INFO) << "Scan " << (_running ? "complete" : "aborted") << ". Changes = " << stats.nbChanges() << " (added = " << stats.additions << ", removed = " << stats.deletions << ", updated = " << stats.updates << "), Not changed = " << stats.skips << ", Scanned = " << stats.scans << " (errors = " << stats.errors.size() << "), features fetched = " << stats.featuresFetched << "/" << stats.featuresToFetch <<",  duplicates = " << stats.duplicates.size();
 
 	LMS_LOG(DBUPDATER, INFO) << "Optimizing db...";
 	_dbSession.optimize();
@@ -449,6 +455,76 @@ MediaScanner::scan(boost::system::error_code err)
 	}
 }
 
+bool
+MediaScanner::fetchTrackFeatures(Database::IdType trackId, const UUID& MBID)
+{
+	std::map<std::string, double> features;
+
+	LMS_LOG(DBUPDATER, INFO) << "Fetching low level features for track '" << MBID.getAsString() << "'";
+	const std::string data {AcousticBrainz::extractLowLevelFeatures(MBID)};
+	if (data.empty())
+	{
+		LMS_LOG(DBUPDATER, ERROR) << "Track " << trackId << ", MBID = '" << MBID.getAsString() << "': cannot extract features using AcousticBrainz";
+		return false;
+	}
+
+	{
+		auto uniqueTransaction {_dbSession.createUniqueTransaction()};
+
+		Wt::Dbo::ptr<Database::Track> track {Database::Track::getById(_dbSession, trackId)};
+		if (!track)
+			return false;
+
+		Database::TrackFeatures::create(_dbSession, track, data);
+	}
+
+	return true;
+}
+
+void
+MediaScanner::fetchTrackFeatures(ScanStats& stats)
+{
+	if (_recommendationEngineType != ScanSettings::RecommendationEngineType::Features)
+		return;
+
+	LMS_LOG(DBUPDATER, INFO) << "Fetching missing track features...";
+
+	struct TrackInfo
+	{
+		Database::IdType id;
+		UUID mbid;
+	};
+
+	const auto tracksToFetch {[&]()
+	{
+		std::vector<TrackInfo> res;
+
+		auto transaction {_dbSession.createSharedTransaction()};
+
+		auto tracks {Database::Track::getAllWithMBIDAndMissingFeatures(_dbSession)};
+		for (const auto& track : tracks)
+			res.emplace_back(TrackInfo {track.id(), *track->getMBID()});
+
+		return res;
+	}()};
+
+	stats.featuresToFetch = tracksToFetch.size();
+
+	LMS_LOG(DBUPDATER, INFO) << "Found " << tracksToFetch.size() << " track(s) to fetch!";
+
+	for (const TrackInfo& trackToFetch : tracksToFetch)
+	{
+		if (!_running)
+			return;
+
+		if (fetchTrackFeatures(trackToFetch.id, trackToFetch.mbid))
+			stats.featuresFetched++;
+
+	}
+
+	LMS_LOG(DBUPDATER, INFO) << "Track features fetched!";
+}
+
 void
 MediaScanner::refreshScanSettings()
 {
@@ -464,6 +540,7 @@ MediaScanner::refreshScanSettings()
 
 	_fileExtensions = scanSettings->getAudioFileExtensions();
 	_mediaDirectory = scanSettings->getMediaDirectory();
+	_recommendationEngineType = scanSettings->getRecommendationEngineType();
 
 	auto clusterTypes = scanSettings->getClusterTypes();
 	std::set<std::string> clusterTypeNames;
@@ -648,6 +725,7 @@ MediaScanner::scanAudioFile(const std::filesystem::path& file, bool forceScan, S
 		track.modify()->setYear(*trackInfo->originalYear);
 
 	track.modify()->setMBID(trackInfo->musicBrainzRecordID);
+	track.modify()->setFeatures({}); // TODO: only if MBID changed?
 	track.modify()->setHasCover(trackInfo->hasCover);
 	track.modify()->setCopyright(trackInfo->copyright);
 	track.modify()->setCopyrightURL(trackInfo->copyrightURL);

src/libs/scanner/impl/MediaScanner.hpp

@@ -35,6 +35,7 @@
 #include "metadata/IParser.hpp"
 #include "scanner/IMediaScanner.hpp"
 
+class UUID;
 
 namespace Scanner {
 
@@ -72,6 +73,8 @@ class MediaScanner : public IMediaScanner
 		void scan(boost::system::error_code ec);
 
 		void scanMediaDirectory( const std::filesystem::path& mediaDirectory, bool forceScan, ScanStats& stats);
+		bool fetchTrackFeatures(Database::IdType trackId, const UUID& MBID);
+		void fetchTrackFeatures(ScanStats& stats);
 
 		// Helpers
 		void refreshScanSettings();
@@ -102,11 +105,12 @@ class MediaScanner : public IMediaScanner
 		Wt::WDateTime				_nextScheduledScan;
 
 		// Current scan settings
-		std::size_t _scanVersion {};
-		Wt::WTime _startTime;
+		std::size_t				_scanVersion {};
+		Wt::WTime				_startTime;
 		Database::ScanSettings::UpdatePeriod 	_updatePeriod {Database::ScanSettings::UpdatePeriod::Never};
 		std::set<std::filesystem::path>		_fileExtensions;
 		std::filesystem::path			_mediaDirectory;
+		Database::ScanSettings::RecommendationEngineType _recommendationEngineType;
 
 
 }; // class MediaScanner

src/libs/scanner/include/scanner/MediaScannerStats.hpp

@@ -77,10 +77,13 @@ namespace Scanner {
 		std::size_t	skips {};		// no change since last scan
 		std::size_t	scans {};		// actually scanned filed
 
-		std::size_t	additions {};		// Added in DB
+		std::size_t	additions {};		// added in DB
 		std::size_t	deletions {};		// removed from DB
 		std::size_t	updates {};		// updated file in DB
 
+		std::size_t	featuresFetched {};	// features fetched in DB
+		std::size_t	featuresToFetch {};	// features to be fetched in DB
+
 		std::vector<ScanError>		errors;
 		std::vector<ScanDuplicate>	duplicates;
 

src/libs/som/CMakeLists.txt

@@ -16,3 +16,5 @@ target_link_libraries(lmssom PUBLIC
 	lmsutils
 	)
 
+set_property(TARGET lmssom PROPERTY POSITION_INDEPENDENT_CODE ON)
+

src/libs/som/impl/Network.cpp

@@ -201,9 +201,9 @@ Network::getClosestRefVectorPosition(const InputVector& data, InputVector::Dista
 }
 
 std::optional<Position>
-Network::getClosestRefVectorPosition(const std::set<Position>& refVectorsPosition, InputVector::Distance maxDistance) const
+Network::getClosestRefVectorPosition(const std::unordered_set<Position>& refVectorsPosition, InputVector::Distance maxDistance) const
 {
-	std::set<Position> neighboursPosition;
+	std::unordered_set<Position> neighboursPosition;
 	for (const Position& refVectorPosition : refVectorsPosition)
 	{
 		if (refVectorPosition.y > 0)

src/libs/som/include/som/InputVector.hpp

@@ -31,7 +31,7 @@ namespace SOM
 class Exception : public LmsException
 {
 	public:
-		Exception(const std::string& msg) : LmsException(msg) {}
+		using LmsException::LmsException;
 };
 
 class InputVector

src/libs/som/include/som/Matrix.hpp

@@ -21,7 +21,7 @@
 
 #include <algorithm>
 #include <cassert>
-#include <sstream>
+#include <functional>
 #include <vector>
 
 namespace SOM
@@ -116,3 +116,20 @@ class Matrix
 };
 
 } // ns SOM
+
+namespace std {
+
+template<>
+class hash<SOM::Position>
+{
+	public:
+		size_t operator()(const SOM::Position& s) const
+		{
+			size_t h1 = std::hash<SOM::Coordinate>()(s.x);
+			size_t h2 = std::hash<SOM::Coordinate>()(s.y);
+			return h1 ^ (h2 << 1);
+		}
+};
+
+} // ns std
+

src/libs/som/include/som/Network.hpp

@@ -20,7 +20,7 @@
 #pragma once
 
 #include <vector>
-#include <set>
+#include <unordered_set>
 #include <optional>
 #include <ostream>
 #include <functional>
@@ -70,7 +70,7 @@ class Network
 		Position getClosestRefVectorPosition(const InputVector& data) const;
 		std::optional<Position> getClosestRefVectorPosition(const InputVector& data, InputVector::Distance maxDistance) const;
 
-		std::optional<Position> getClosestRefVectorPosition(const std::set<Position>& refVectorsPosition, InputVector::Distance maxDistance) const;
+		std::optional<Position> getClosestRefVectorPosition(const std::unordered_set<Position>& refVectorsPosition, InputVector::Distance maxDistance) const;
 
 		InputVector::Distance getRefVectorsDistance(const Position& position1, const Position& position2) const;