Rework DB session + transactions. Now can handle multiple read only transactions in parallel

src/ui/Auth.cpp

@@ -34,21 +34,21 @@ namespace UserInterface {
 Auth::Auth()
 : Wt::WTemplateFormView(Wt::WString::tr("Lms.Auth.template"))
 {
-	_model = std::make_shared<Wt::Auth::AuthModel>(LmsApp->getDb().getAuthService(), LmsApp->getDb().getUserDatabase());
-	_model->addPasswordAuth(&Database::Handler::getPasswordService());
+	_model = std::make_shared<Wt::Auth::AuthModel>(LmsApp->getDbSession().getAuthService(), LmsApp->getDbSession().getUserDatabase());
+	_model->addPasswordAuth(&Database::Session::getPasswordService());
 
 	// LoginName
 	setFormWidget(Wt::Auth::AuthModel::LoginNameField, std::make_unique<Wt::WLineEdit>());
 
 	{
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-		auto demoUser = Database::User::getDemo(LmsApp->getDboSession());
+		auto demoUser = Database::User::getDemo(LmsApp->getDbSession());
 		if (demoUser)
 		{
-			Wt::Auth::User authUser = LmsApp->getDb().getUserDatabase().findWithId(std::to_string(demoUser.id()));
-			_model->setValue(Wt::Auth::AuthModel::LoginNameField, authUser.identity(Wt::Auth::Identity::LoginName));
-			_model->setValue(Wt::Auth::AuthModel::PasswordField, authUser.identity(Wt::Auth::Identity::LoginName));
+			const std::string userName {LmsApp->getDbSession().getUserLoginName(demoUser)};
+			_model->setValue(Wt::Auth::AuthModel::LoginNameField, userName );
+			_model->setValue(Wt::Auth::AuthModel::PasswordField, userName);
 		}
 	}
 
@@ -64,9 +64,9 @@ Auth::Auth()
 	Wt::WPushButton* loginBtn = bindNew<Wt::WPushButton>("login-btn", Wt::WString::tr("Lms.login"));
 	loginBtn->clicked().connect(this, &Auth::processAuth);
 
-	LmsApp->getDb().getLogin().changed().connect(std::bind([=]
+	LmsApp->getDbSession().getLogin().changed().connect(std::bind([=]
 	{
-		if (LmsApp->getDb().getLogin().loggedIn())
+		if (LmsApp->getDbSession().getLogin().loggedIn())
 			this->setHidden(true);
 	}));
 
@@ -76,7 +76,7 @@ Auth::Auth()
 	if (user.isValid())
 	{
 		LMS_LOG(UI, DEBUG) << "Valid user found from auth token (id = " << user.id() << ")";
-		_model->loginUser(LmsApp->getDb().getLogin(), user, Wt::Auth::LoginState::Weak);
+		_model->loginUser(LmsApp->getDbSession().getLogin(), user, Wt::Auth::LoginState::Weak);
 	}
 }
 
@@ -86,7 +86,7 @@ Auth::processAuth()
 	updateModel(_model.get());
 
 	if (_model->validate())
-		_model->login(LmsApp->getDb().getLogin());
+		_model->login(LmsApp->getDbSession().getLogin());
 	else
 		updateView(_model.get());
 }
@@ -94,7 +94,7 @@ Auth::processAuth()
 void
 Auth::logout()
 {
-	_model->logout(LmsApp->getDb().getLogin());
+	_model->logout(LmsApp->getDbSession().getLogin());
 }
 
 } // namespace UserInterface

src/ui/LmsApplication.cpp

@@ -55,9 +55,9 @@
 namespace UserInterface {
 
 std::unique_ptr<Wt::WApplication>
-LmsApplication::create(const Wt::WEnvironment& env, Wt::Dbo::SqlConnectionPool& connectionPool, LmsApplicationGroupContainer& appGroups)
+LmsApplication::create(const Wt::WEnvironment& env, Database::Database& db, LmsApplicationGroupContainer& appGroups)
 {
-	return std::make_unique<LmsApplication>(env, connectionPool, appGroups);
+	return std::make_unique<LmsApplication>(env, db.createSession(), appGroups);
 }
 
 LmsApplication*
@@ -67,11 +67,11 @@ LmsApplication::instance()
 }
 
 LmsApplication::LmsApplication(const Wt::WEnvironment& env,
-		Wt::Dbo::SqlConnectionPool& connectionPool,
+		std::unique_ptr<Database::Session> dbSession,
 		LmsApplicationGroupContainer& appGroups)
-: Wt::WApplication(env),
-  _db(connectionPool),
-  _appGroups(appGroups)
+: Wt::WApplication {env},
+  _dbSession {std::move(dbSession)},
+  _appGroups {appGroups}
 {
 	auto  bootstrapTheme = std::make_unique<Wt::WBootstrapTheme>();
 	bootstrapTheme->setVersion(Wt::BootstrapVersion::v3);
@@ -116,12 +116,14 @@ LmsApplication::LmsApplication(const Wt::WEnvironment& env,
 
 	setTitle("LMS");
 
-	// If here is no account in the database, launch the first connection wizard
-	bool firstConnection;
-	{
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	// Handle Media Scanner events and other session events
+	enableUpdates(true);
 
-		firstConnection = (Database::User::getAll(LmsApp->getDboSession()).size() == 0);
+	// If here is no account in the database, launch the first connection wizard
+	bool firstConnection {};
+	{
+		auto transaction {_dbSession->createSharedTransaction()};
+		firstConnection = Database::User::getAll(*_dbSession).empty();
 	}
 
 	LMS_LOG(UI, DEBUG) << "Creating root widget. First connection = " << firstConnection;
@@ -132,7 +134,7 @@ LmsApplication::LmsApplication(const Wt::WEnvironment& env,
 	}
 	else
 	{
-		LmsApp->getDb().getLogin().changed().connect(this, &LmsApplication::handleAuthEvent);
+		LmsApp->getDbSession().getLogin().changed().connect(this, &LmsApplication::handleAuthEvent);
 		_auth = root()->addNew<Auth>();
 	}
 }
@@ -260,7 +262,7 @@ handlePathChange(Wt::WStackedWidget* stack, bool isAdmin)
 
 	LMS_LOG(UI, DEBUG) << "Internal path changed to '" << wApp->internalPath() << "'";
 
-	for (auto& view : views)
+	for (const auto& view : views)
 	{
 		if (wApp->internalPathMatches(view.path))
 		{
@@ -284,46 +286,46 @@ LmsApplication::getApplicationGroup()
 void
 LmsApplication::handleAuthEvent()
 {
+	if (!getDbSession().getLogin().loggedIn())
+	{
+		LMS_LOG(UI, INFO) << "User '" << _userIdentity << " 'logged out, session = " << sessionId();
+
+		goHomeAndQuit();
+		return;
+	}
+
 	try
 	{
-		if (!getDb().getLogin().loggedIn())
+//	post([this]
+//	{
+		_userIdentity = getAuthUser().identity(Wt::Auth::Identity::LoginName);
+		const LmsApplicationInfo info {LmsApplicationInfo::fromEnvironment(environment())};
+
+		LMS_LOG(UI, INFO) << "User '" << _userIdentity << "' logged in from '" << environment().clientAddress() << "', user agent = " << environment().userAgent() << ", session = " <<  sessionId();
+		getApplicationGroup().join(info);
+
+		getApplicationGroup().postOthers([info]
 		{
-			LMS_LOG(UI, INFO) << "User '" << _userIdentity << " 'logged out, session = " << sessionId();
+			LmsApp->getEvents().appOpen(info);
+		});
 
-			goHomeAndQuit();
-			return;
-		}
-		else
-		{
-			_userIdentity = getAuthUser().identity(Wt::Auth::Identity::LoginName);
-			LmsApplicationInfo info = LmsApplicationInfo::fromEnvironment(environment());
-
-			LMS_LOG(UI, INFO) << "User '" << _userIdentity << "' logged in from '" << environment().clientAddress() << "', user agent = " << environment().userAgent() << ", session = " <<  sessionId();
-			getApplicationGroup().join(info);
-
-			getApplicationGroup().postOthers([info]
-			{
-				LmsApp->getEvents().appOpen(info);
-			});
-
-			createHome();
-		}
+		createHome();
+		triggerUpdate();
+//	});
 	}
 	catch (std::exception& e)
 	{
 		LMS_LOG(UI, ERROR) << "Error while handling auth event: " << e.what();
-		throw LmsException("Internal error"); // Do not put details here at it appears on the user rendered html
+		throw LmsException {"Internal error"}; // Do not put details here at it appears on the user rendered html
 	}
 }
 
 void
 LmsApplication::createHome()
 {
-	// Handle Media Scanner events and other session events
-	enableUpdates(true);
 
 	{
-		Wt::Dbo::Transaction transaction (LmsApp->getDboSession());
+		auto transaction {_dbSession->createSharedTransaction()};
 		_isAdmin = LmsApp->getUser()->isAdmin();
 	}
 
@@ -332,14 +334,14 @@ LmsApplication::createHome()
 
 	setConfirmCloseMessage(Wt::WString::tr("Lms.quit-confirm"));
 
-	Wt::WTemplate* main = root()->addWidget(std::make_unique<Wt::WTemplate>(Wt::WString::tr("Lms.template")));
+	Wt::WTemplate* main {root()->addWidget(std::make_unique<Wt::WTemplate>(Wt::WString::tr("Lms.template")))};
 
 	// Navbar
 	Wt::WNavigationBar* navbar = main->bindNew<Wt::WNavigationBar>("navbar-top");
 	navbar->setTitle("LMS", Wt::WLink(Wt::LinkType::InternalPath, "/artists"));
 	navbar->setResponsive(true);
 
-	Wt::WMenu* menu = navbar->addMenu(std::make_unique<Wt::WMenu>());
+	Wt::WMenu* menu {navbar->addMenu(std::make_unique<Wt::WMenu>())};
 	{
 		auto menuItem = menu->insertItem(0, Wt::WString::tr("Lms.Explore.artists"));
 		menuItem->setLink(Wt::WLink(Wt::LinkType::InternalPath, "/artists"));
@@ -417,14 +419,14 @@ LmsApplication::createHome()
 		mainStack->addNew<UserView>();
 	}
 
-	explore->tracksAdd.connect([=] (std::vector<Database::Track::pointer> tracks)
+	explore->tracksAdd.connect([=] (const std::vector<Database::IdType>& trackIds)
 	{
-		playqueue->addTracks(tracks);
+		playqueue->addTracks(trackIds);
 	});
 
-	explore->tracksPlay.connect([=] (std::vector<Database::Track::pointer> tracks)
+	explore->tracksPlay.connect([=] (const std::vector<Database::IdType>& trackIds)
 	{
-		playqueue->playTracks(tracks);
+		playqueue->playTracks(trackIds);
 	});
 
 
@@ -459,7 +461,7 @@ LmsApplication::createHome()
 
 	// Events from MediaScanner
 	{
-		std::string sessionId = LmsApp->sessionId();
+		const std::string sessionId {LmsApp->sessionId()};
 		getService<Scanner::MediaScanner>()->scanComplete().connect(this, [=] (Scanner::MediaScanner::Stats stats)
 		{
 			Wt::WServer::instance()->post(sessionId, [=]
@@ -551,7 +553,7 @@ static std::string msgTypeToString(MsgType type)
 void
 LmsApplication::post(std::function<void()> func)
 {
-	Wt::WServer::instance()->post(LmsApp->sessionId(), func);
+	Wt::WServer::instance()->post(LmsApp->sessionId(), std::move(func));
 }
 
 static std::string escape(std::string str)

src/ui/LmsApplication.hpp

@@ -23,9 +23,8 @@
 #include <boost/optional.hpp>
 
 #include <Wt/WApplication.h>
-#include <Wt/Dbo/SqlConnectionPool.h>
 
-#include "database/DatabaseHandler.hpp"
+#include "database/Database.hpp"
 #include "scanner/MediaScanner.hpp"
 
 #include "LmsApplicationGroup.hpp"
@@ -35,6 +34,7 @@ namespace Database {
 	class Artist;
 	class Cluster;
 	class Release;
+	class User;
 }
 
 namespace UserInterface {
@@ -73,20 +73,18 @@ enum class MsgType
 class LmsApplication : public Wt::WApplication
 {
 	public:
-		LmsApplication(const Wt::WEnvironment& env, Wt::Dbo::SqlConnectionPool& connectionPool, LmsApplicationGroupContainer& appGroups);
+		LmsApplication(const Wt::WEnvironment& env, std::unique_ptr<Database::Session> dbSession, LmsApplicationGroupContainer& appGroups);
 
-		static std::unique_ptr<Wt::WApplication> create(const Wt::WEnvironment& env,
-				Wt::Dbo::SqlConnectionPool& connectionPool, LmsApplicationGroupContainer& appGroups);
+		static std::unique_ptr<Wt::WApplication> create(const Wt::WEnvironment& env, Database::Database& db, LmsApplicationGroupContainer& appGroups);
 		static LmsApplication* instance();
 
 		// Session application data
 		std::shared_ptr<ImageResource> getImageResource() { return _imageResource; }
 		std::shared_ptr<AudioResource> getAudioResource() { return _audioResource; }
-		Database::Handler& getDb() { return _db;}
-		Wt::Dbo::Session& getDboSession() { return _db.getSession();}
+		Database::Session& getDbSession() { return *_dbSession.get();}
 
-		const Wt::Auth::User& getAuthUser() { return _db.getLogin().user(); }
-		Database::User::pointer getUser() { return _db.getCurrentUser(); }
+		const Wt::Auth::User& getAuthUser() { return getDbSession().getLogin().user(); }
+		Wt::Dbo::ptr<Database::User> getUser() { return getDbSession().getLoggedUser(); }
 		Wt::WString getUserIdentity() { return _userIdentity; }
 
 		Events& getEvents() { return _events; }
@@ -118,15 +116,15 @@ class LmsApplication : public Wt::WApplication
 
 		void createHome();
 
-		Wt::Signal<>		_preQuit;
-		Database::Handler	_db;
-		LmsApplicationGroupContainer&   _appGroups;
-		Events			_events;
-		Wt::WString		_userIdentity;
-		Auth*			_auth = nullptr;
-		std::shared_ptr<ImageResource>	_imageResource;
-		std::shared_ptr<AudioResource>	_audioResource;
-		bool			_isAdmin = false;
+		Wt::Signal<>				_preQuit;
+		std::unique_ptr<Database::Session>	_dbSession;
+		LmsApplicationGroupContainer&   	_appGroups;
+		Events					_events;
+		Wt::WString				_userIdentity;
+		Auth*					_auth {};
+		std::shared_ptr<ImageResource>		_imageResource;
+		std::shared_ptr<AudioResource>		_audioResource;
+		bool					_isAdmin {};
 };
 
 

src/ui/MediaPlayer.cpp

@@ -59,12 +59,12 @@ MediaPlayer::loadTrack(Database::IdType trackId, bool play)
 {
 	LMS_LOG(UI, DEBUG) << "Playing track ID = " << trackId;
 
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-	auto track = Database::Track::getById(LmsApp->getDboSession(), trackId);
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+	const auto track {Database::Track::getById(LmsApp->getDbSession(), trackId)};
 
 	try
 	{
-		Av::MediaFile mediaFile(track->getPath());
+		const Av::MediaFile mediaFile {track->getPath()};
 
 		auto resource = LmsApp->getAudioResource()->getUrl(trackId);
 		auto imgResource = LmsApp->getImageResource()->getTrackUrl(trackId, 64);

src/ui/PlayHistoryView.cpp

@@ -70,7 +70,7 @@ std::unique_ptr<Wt::WTemplate> createEntry(Database::Track::pointer track)
 namespace UserInterface {
 
 PlayHistory::PlayHistory()
-: Wt::WTemplate(Wt::WString::tr("Lms.PlayHistory.template"))
+: Wt::WTemplate {Wt::WString::tr("Lms.PlayHistory.template")}
 {
 	addFunction("tr", &Wt::WTemplate::Functions::tr);
 
@@ -86,10 +86,14 @@ PlayHistory::PlayHistory()
 
 	LmsApp->getEvents().trackLoaded.connect([=](Database::IdType trackId, bool /* play */)
 	{
-		Wt::Dbo::Transaction transaction (LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
 
-		auto trackEntry = LmsApp->getUser()->getPlayedTrackList().modify()->add(trackId);
-		_entriesContainer->insertWidget(0, createEntry(trackEntry->getTrack()));
+		Database::Track::pointer track {Database::Track::getById(LmsApp->getDbSession(), trackId)};
+		if (track)
+		{
+			Database::TrackListEntry::create(LmsApp->getDbSession(), track, LmsApp->getUser()->getPlayedTrackList(LmsApp->getDbSession()));
+			_entriesContainer->insertWidget(0, createEntry(track));
+		}
 	});
 
 	addSome();
@@ -98,11 +102,11 @@ PlayHistory::PlayHistory()
 void
 PlayHistory::addSome()
 {
-	Wt::Dbo::Transaction transaction (LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	auto trackList = LmsApp->getUser()->getPlayedTrackList();
-	auto trackEntries = trackList->getEntriesReverse(_entriesContainer->count(), 50);
-	for (auto trackEntry : trackEntries)
+	const Database::TrackList::pointer trackList {LmsApp->getUser()->getPlayedTrackList(LmsApp->getDbSession())};
+	auto trackEntries {trackList->getEntriesReverse(_entriesContainer->count(), 50)};
+	for (const auto& trackEntry : trackEntries)
 		_entriesContainer->addWidget(createEntry(trackEntry->getTrack()));
 
 	_showMore->setHidden(static_cast<std::size_t>(_entriesContainer->count()) >= trackList->getCount());

src/ui/PlayHistoryView.hpp

@@ -23,8 +23,6 @@
 #include <Wt/WPushButton.h>
 #include <Wt/WTemplate.h>
 
-#include "database/Types.hpp"
-
 namespace UserInterface {
 
 class PlayHistory : public Wt::WTemplate

src/ui/PlayQueueView.cpp

@@ -19,12 +19,15 @@
 
 #include "PlayQueueView.hpp"
 
+#include <Wt/WText.h>
 #include <Wt/WText.h>
 
+#include "database/Track.hpp"
 #include "database/TrackList.hpp"
 #include "main/Service.hpp"
 #include "similarity/SimilaritySearcher.hpp"
 #include "utils/Logger.hpp"
+#include "utils/Utils.hpp"
 #include "LmsApplication.hpp"
 
 namespace UserInterface {
@@ -35,7 +38,7 @@ PlayQueue::PlayQueue()
 	addFunction("tr", &Wt::WTemplate::Functions::tr);
 
 	{
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 		_repeatAll = LmsApp->getUser()->isRepeatAllSet();
 		_radioMode = LmsApp->getUser()->isRadioSet();
 	}
@@ -62,9 +65,15 @@ PlayQueue::PlayQueue()
 	shuffleBtn->clicked().connect([=]
 	{
 		{
-			Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+			auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
 
-			getTrackList().modify()->shuffle();
+			Database::TrackList::pointer trackList {getTrackList()};
+			auto entries {trackList->getEntries()};
+			shuffleContainer(entries);
+
+			getTrackList().modify()->clear();
+			for (const auto& entry : entries)
+				Database::TrackListEntry::create(LmsApp->getDbSession(), entry->getTrack(), trackList);
 		}
 		_entriesContainer->clear();
 		addSome();
@@ -77,7 +86,7 @@ PlayQueue::PlayQueue()
 		_repeatAll = !_repeatAll;
 		updateRepeatBtn();
 
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
 
 		if (!LmsApp->getUser()->isDemo())
 			LmsApp->getUser().modify()->setRepeatAll(_repeatAll);
@@ -91,7 +100,7 @@ PlayQueue::PlayQueue()
 		_radioMode = !_radioMode;
 		updateRadioBtn();
 
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
 
 		if (!LmsApp->getUser()->isDemo())
 			LmsApp->getUser().modify()->setRadio(_radioMode);
@@ -102,23 +111,21 @@ PlayQueue::PlayQueue()
 
 	LmsApp->preQuit().connect([=]
 	{
-		if (_tracklistId)
+		auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
+
+		if (LmsApp->getUser()->isDemo())
 		{
-			LMS_LOG(UI, DEBUG) << "Removing tracklist id " << *_tracklistId;
-
-			Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-
-			auto tracklist = Database::TrackList::getById(LmsApp->getDboSession(), *_tracklistId);
+			LMS_LOG(UI, DEBUG) << "Removing tracklist id " << _tracklistId;
+			auto tracklist = Database::TrackList::getById(LmsApp->getDbSession(), _tracklistId);
 			if (tracklist)
 				tracklist.remove();
 		}
 	});
 
-	updateInfo();
-	addSome();
-
 	{
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
+
+		Database::TrackList::pointer trackList;
 
 		if (!LmsApp->getUser()->isDemo())
 		{
@@ -126,8 +133,19 @@ PlayQueue::PlayQueue()
 			{
 				load(LmsApp->getUser()->getCurPlayingTrackPos(), false);
 			});
+			trackList = LmsApp->getUser()->getQueuedTrackList(LmsApp->getDbSession());
 		}
+		else
+		{
+			static const std::string currentPlayQueueName {"__current__playqueue__"};
+			trackList = Database::TrackList::create(LmsApp->getDbSession(), currentPlayQueueName, Database::TrackList::Type::Internal, false, LmsApp->getUser());
+		}
+
+		_tracklistId = trackList.id();
 	}
+
+	updateInfo();
+	addSome();
 }
 
 void
@@ -145,32 +163,17 @@ PlayQueue::updateRadioBtn()
 Database::TrackList::pointer
 PlayQueue::getTrackList()
 {
-	Database::TrackList::pointer res;
-
-	if (LmsApp->getUser()->isDemo())
-	{
-		static const std::string currentPlayQueueName = "__current__playqueue__";
-
-		if (!_tracklistId)
-		{
-			res = Database::TrackList::create(LmsApp->getDboSession(), currentPlayQueueName, Database::TrackList::Type::Internal, false, LmsApp->getUser());
-			LmsApp->getDboSession().flush();
-			_tracklistId = res.id();
-			return res;
-		}
-
-		return Database::TrackList::getById(LmsApp->getDboSession(), *_tracklistId);
-	}
-
-	return LmsApp->getUser()->getQueuedTrackList();
+	return Database::TrackList::getById(LmsApp->getDbSession(), _tracklistId);
 }
 
 void
 PlayQueue::clearTracks()
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	{
+		auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
+		getTrackList().modify()->clear();
+	}
 
-	getTrackList().modify()->clear();
 	_showMore->setHidden(true);
 	_entriesContainer->clear();
 	updateInfo();
@@ -189,11 +192,12 @@ PlayQueue::load(std::size_t pos, bool play)
 {
 	updateCurrentTrack(false);
 
-	Database::IdType trackId;
+	Database::IdType trackId {};
+	bool addRadioTrack {};
 	{
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-		auto tracklist = getTrackList();
+		Database::TrackList::pointer tracklist {getTrackList()};
 
 		// If out of range, stop playing
 		if (pos >= tracklist->getCount())
@@ -209,19 +213,22 @@ PlayQueue::load(std::size_t pos, bool play)
 
 		// If last and radio mode, fill the next song
 		if (_radioMode && pos == tracklist->getCount() - 1)
-			addRadioTrack();
+			addRadioTrack = true;
 
 		_trackPos = pos;
 		auto track = tracklist->getEntry(*_trackPos)->getTrack();
 
 		trackId = track.id();
 
-		updateCurrentTrack(true);
-
 		if (!LmsApp->getUser()->isDemo())
 			LmsApp->getUser().modify()->setCurPlayingTrackPos(pos);
 	}
 
+	if (addRadioTrack)
+		enqueueRadioTrack();
+
+	updateCurrentTrack(true);
+
 	loadTrack.emit(trackId, play);
 }
 
@@ -252,7 +259,7 @@ PlayQueue::playNext()
 void
 PlayQueue::updateInfo()
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
 	_nbTracks->setText(Wt::WString::tr("Lms.PlayQueue.nb-tracks").arg(static_cast<unsigned>(getTrackList()->getCount())));
 }
@@ -274,55 +281,58 @@ PlayQueue::updateCurrentTrack(bool selected)
 }
 
 void
-PlayQueue::enqueueTracks(const std::vector<Database::Track::pointer>& tracks)
+PlayQueue::enqueueTracks(const std::vector<Database::IdType>& trackIds)
 {
-	// Use a "session" playqueue in order to store the current playqueue
-	// so that the user can disconnect and get its playqueue back
+	{
+		auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
 
-	auto tracklist = getTrackList();
+		auto tracklist = getTrackList();
+		for (Database::IdType trackId : trackIds)
+		{
+			Database::Track::pointer track {Database::Track::getById(LmsApp->getDbSession(), trackId)};
+			if (!track)
+				continue;
 
-	for (auto track : tracks)
-		Database::TrackListEntry::create(LmsApp->getDboSession(), track, tracklist);
+			Database::TrackListEntry::create(LmsApp->getDbSession(), track, tracklist);
+		}
+	}
 
 	updateInfo();
 	addSome();
 }
 
 void
-PlayQueue::enqueueTrack(Database::Track::pointer track)
+PlayQueue::enqueueTrack(Database::IdType trackId)
 {
-	enqueueTracks(std::vector<Database::Track::pointer>(1, track));
+	enqueueTracks({trackId});
 }
 
 void
-PlayQueue::addTracks(const std::vector<Database::Track::pointer>& tracks)
+PlayQueue::addTracks(const std::vector<Database::IdType>& trackIds)
 {
-	enqueueTracks(tracks);
-	LmsApp->notifyMsg(MsgType::Info, Wt::WString::trn("Lms.PlayQueue.nb-tracks-added", tracks.size()).arg(tracks.size()), std::chrono::milliseconds(2000));
+	enqueueTracks(trackIds);
+	LmsApp->notifyMsg(MsgType::Info, Wt::WString::trn("Lms.PlayQueue.nb-tracks-added", trackIds.size()).arg(trackIds.size()), std::chrono::milliseconds(2000));
 }
 
 void
-PlayQueue::playTracks(const std::vector<Database::Track::pointer>& tracks)
+PlayQueue::playTracks(const std::vector<Database::IdType>& trackIds)
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-
 	clearTracks();
-	enqueueTracks(tracks);
+	enqueueTracks(trackIds);
 	load(0, true);
 
-	LmsApp->notifyMsg(MsgType::Info, Wt::WString::trn("Lms.PlayQueue.nb-tracks-playing", tracks.size()).arg(tracks.size()), std::chrono::milliseconds(2000));
+	LmsApp->notifyMsg(MsgType::Info, Wt::WString::trn("Lms.PlayQueue.nb-tracks-playing", trackIds.size()).arg(trackIds.size()), std::chrono::milliseconds(2000));
 }
 
-
 void
 PlayQueue::addSome()
 {
-	Wt::Dbo::Transaction transaction (LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
 	auto tracklist = getTrackList();
 
 	auto tracklistEntries = tracklist->getEntries(_entriesContainer->count(), 50);
-	for (auto tracklistEntry : tracklistEntries)
+	for (const Database::TrackListEntry::pointer& tracklistEntry : tracklistEntries)
 	{
 		auto tracklistEntryId = tracklistEntry.id();
 		auto track = tracklistEntry->getTrack();
@@ -367,15 +377,15 @@ PlayQueue::addSome()
 		{
 			// Remove the entry n both the widget tree and the playqueue
 			{
-				Wt::Dbo::Transaction transaction (LmsApp->getDboSession());
+				auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
 
-				auto entryToRemove = Database::TrackListEntry::getById(LmsApp->getDboSession(), tracklistEntryId);
+				Database::TrackListEntry::pointer entryToRemove {Database::TrackListEntry::getById(LmsApp->getDbSession(), tracklistEntryId)};
 				entryToRemove.remove();
 			}
 
 			if (_trackPos)
 			{
-				auto pos = _entriesContainer->indexOf(entry);
+				auto pos {_entriesContainer->indexOf(entry)};
 				if (pos > 0 && *_trackPos >= static_cast<std::size_t>(pos))
 					(*_trackPos)--;
 			}
@@ -391,28 +401,23 @@ PlayQueue::addSome()
 }
 
 void
-PlayQueue::addRadioTrack()
+PlayQueue::enqueueRadioTrack()
 {
-	auto tracklist = getTrackList();
+	std::vector<Database::IdType> trackIds;
+
+	{
+		auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+		Database::TrackList::pointer tracklist {getTrackList()};
+
+		trackIds = getTrackList()->getTrackIds();
+	}
 
-	std::vector<Database::IdType> trackIds = getTrackList()->getTrackIds();
 	if (trackIds.empty())
 		return;
 
-	auto res = getService<Similarity::Searcher>()->getSimilarTracks(LmsApp->getDboSession(), std::set<Database::IdType>(trackIds.begin(), trackIds.end()), 1);
-	for (auto trackId : res)
-	{
-		auto trackToAdd = Database::Track::getById(LmsApp->getDboSession(), trackId);
-		enqueueTrack(trackToAdd);
-	}
-
+	const std::vector<Database::IdType> trackToAddIds {getService<Similarity::Searcher>()->getSimilarTracks(LmsApp->getDbSession(), std::set<Database::IdType>(std::cbegin(trackIds), std::cend(trackIds)), 1)};
+	enqueueTracks(trackToAddIds);
 }
 
-void addRadioTrackFromSimilarity(std::shared_ptr<Similarity::Searcher> similaritySearcher)
-{
-
-}
-
-
 } // namespace UserInterface
 

src/ui/PlayQueueView.hpp

@@ -19,23 +19,23 @@
 
 #pragma once
 
-#include <Wt/WCheckBox.h>
 #include <Wt/WContainerWidget.h>
 #include <Wt/WPushButton.h>
-#include <Wt/WSignal.h>
 #include <Wt/WTemplate.h>
 #include <Wt/WText.h>
 
 #include <boost/optional.hpp>
 
-#include "database/TrackList.hpp"
-#include "database/Track.hpp"
+#include "database/Types.hpp"
 
-namespace Similarity
-{
+namespace Similarity {
 	class Finder;
 }
 
+namespace Database {
+	class TrackList;
+}
+
 namespace UserInterface {
 
 class PlayQueue : public Wt::WTemplate
@@ -43,8 +43,8 @@ class PlayQueue : public Wt::WTemplate
 	public:
 		PlayQueue();
 
-		void addTracks(const std::vector<Database::Track::pointer>& tracks);
-		void playTracks(const std::vector<Database::Track::pointer>& tracks);
+		void addTracks(const std::vector<Database::IdType>& trackIds);
+		void playTracks(const std::vector<Database::IdType>& trackIds);
 
 		// play the next track in the queue
 		void playNext();
@@ -59,13 +59,13 @@ class PlayQueue : public Wt::WTemplate
 		Wt::Signal<> trackUnload;
 
 	private:
-		Database::TrackList::pointer getTrackList();
+		Wt::Dbo::ptr<Database::TrackList> getTrackList();
 
 		void clearTracks();
-		void enqueueTracks(const std::vector<Database::Track::pointer>& tracks);
-		void enqueueTrack(Database::Track::pointer track);
+		void enqueueTracks(const std::vector<Database::IdType>& trackIds);
+		void enqueueTrack(Database::IdType trackId);
 		void addSome();
-		void addRadioTrack();
+		void enqueueRadioTrack();
 		void updateInfo();
 		void updateCurrentTrack(bool selected);
 		void updateRepeatBtn();
@@ -77,14 +77,14 @@ class PlayQueue : public Wt::WTemplate
 		void addRadioTrackFromSimilarity(std::shared_ptr<Similarity::Finder> similarityFinder);
 		void addRadioTrackFromClusters();
 
-		bool _repeatAll = false;
-		bool _radioMode = false;
-		boost::optional<Database::IdType> _tracklistId;
-		Wt::WContainerWidget* _entriesContainer = nullptr;
-		Wt::WPushButton* _showMore = nullptr;
-		Wt::WText* _nbTracks = nullptr;
-		Wt::WText* _repeatBtn = nullptr;
-		Wt::WText* _radioBtn = nullptr;
+		bool _repeatAll {};
+		bool _radioMode {};
+		Database::IdType _tracklistId {};
+		Wt::WContainerWidget* _entriesContainer {};
+		Wt::WPushButton* _showMore {};
+		Wt::WText* _nbTracks {};
+		Wt::WText* _repeatBtn {};
+		Wt::WText* _radioBtn {};
 		boost::optional<std::size_t> _trackPos;	// current track position, if set
 };
 

src/ui/SettingsView.cpp

@@ -69,7 +69,7 @@ class SettingsModel : public Wt::WFormModel
 
 		void saveData()
 		{
-			Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+			auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
 
 			LmsApp->getUser().modify()->setAudioTranscodeEnable(Wt::asNumber(value(TranscodeEnableField)));
 
@@ -82,12 +82,12 @@ class SettingsModel : public Wt::WFormModel
 				LmsApp->getUser().modify()->setAudioTranscodeFormat(_transcodeFormatModel->getValue(*transcodeFormatRow));
 
 			if (!valueText(PasswordField).empty())
-				Handler::getPasswordService().updatePassword(LmsApp->getAuthUser(), valueText(PasswordField));
+				Session::getPasswordService().updatePassword(LmsApp->getAuthUser(), valueText(PasswordField));
 		}
 
 		void loadData()
 		{
-			Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+			auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
 			setValue(TranscodeEnableField, LmsApp->getUser()->getAudioTranscodeEnable());
 			if (!LmsApp->getUser()->getAudioTranscodeEnable())
@@ -116,7 +116,7 @@ class SettingsModel : public Wt::WFormModel
 				if (!valueText(PasswordField).empty())
 				{
 					// Evaluate the strength of the password
-					auto res = Handler::getPasswordService().strengthValidator()->evaluateStrength(valueText(PasswordField), LmsApp->getUserIdentity(), "");
+					auto res = Session::getPasswordService().strengthValidator()->evaluateStrength(valueText(PasswordField), LmsApp->getUserIdentity(), "");
 
 					if (!res.isValid())
 						error = res.message();
@@ -148,12 +148,12 @@ class SettingsModel : public Wt::WFormModel
 		{
 			Bitrate maxAudioBitrate;
 			{
-				Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+				auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 				maxAudioBitrate = LmsApp->getUser()->getMaxAudioTranscodeBitrate();
 			}
 
 			_transcodeBitrateModel = std::make_shared<ValueStringModel<Bitrate>>();
-			for (Bitrate bitrate : User::audioTranscodeAllowedBitrates)
+			for (const Bitrate bitrate : User::audioTranscodeAllowedBitrates)
 			{
 				if (bitrate > maxAudioBitrate)
 					break;
@@ -243,7 +243,7 @@ SettingsView::refreshView()
 	{
 
 		{
-			Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+			auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
 			if (LmsApp->getUser()->isDemo())
 			{

src/ui/admin/DatabaseSettingsView.cpp

@@ -85,10 +85,10 @@ class DatabaseSettingsModel : public Wt::WFormModel
 
 		void loadData()
 		{
-			Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+			auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-			auto scanSettings {ScanSettings::get(LmsApp->getDboSession())};
-			auto similaritySettings {SimilaritySettings::get(LmsApp->getDboSession())};
+			const ScanSettings::pointer scanSettings {ScanSettings::get(LmsApp->getDbSession())};
+			const SimilaritySettings::pointer similaritySettings {SimilaritySettings::get(LmsApp->getDbSession())};
 
 			setValue(MediaDirectoryField, scanSettings->getMediaDirectory().string());
 
@@ -108,17 +108,17 @@ class DatabaseSettingsModel : public Wt::WFormModel
 			if (!clusterTypes.empty())
 			{
 				std::vector<std::string> names;
-				std::transform(clusterTypes.begin(), clusterTypes.end(),std::back_inserter(names),  [](auto clusterType) { return clusterType->getName(); });
+				std::transform(clusterTypes.begin(), clusterTypes.end(), std::back_inserter(names),  [](auto clusterType) { return clusterType->getName(); });
 				setValue(TagsField, joinStrings(names, " "));
 			}
 		}
 
 		void saveData()
 		{
-			Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+			auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
 
-			auto scanSettings {ScanSettings::get(LmsApp->getDboSession())};
-			auto similaritySettings {SimilaritySettings::get(LmsApp->getDboSession())};
+			ScanSettings::pointer scanSettings {ScanSettings::get(LmsApp->getDbSession())};
+			SimilaritySettings::pointer similaritySettings {SimilaritySettings::get(LmsApp->getDbSession())};
 
 			scanSettings.modify()->setMediaDirectory(valueText(MediaDirectoryField).toUTF8());
 
@@ -135,7 +135,7 @@ class DatabaseSettingsModel : public Wt::WFormModel
 				similaritySettings.modify()->setEngineType(_similarityEngineTypeModel->getValue(*similarityEngineTypeRow));
 
 			auto clusterTypes {splitString(valueText(TagsField).toUTF8(), " ")};
-			scanSettings.modify()->setClusterTypes(std::set<std::string>(clusterTypes.begin(), clusterTypes.end()));
+			scanSettings.modify()->setClusterTypes(LmsApp->getDbSession(), std::set<std::string>(clusterTypes.begin(), clusterTypes.end()));
 		}
 
 	private:

src/ui/admin/InitWizardView.cpp

@@ -54,21 +54,14 @@ class InitWizardModel : public Wt::WFormModel
 
 		void saveData()
 		{
-			Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+			auto transaction(LmsApp->getDbSession().createUniqueTransaction());
 
 			// Check if a user already exist
 			// If it's the case, just do nothing
-			if (!Database::User::getAll(LmsApp->getDboSession()).empty())
+			if (!Database::User::getAll(LmsApp->getDbSession()).empty())
 				throw LmsException("Admin user already created");
 
-			// Create user
-			Wt::Auth::User authUser = LmsApp->getDb().getUserDatabase().registerNew();
-			Database::User::pointer user = LmsApp->getDb().createUser(authUser);
-
-			// Account
-			authUser.setIdentity(Wt::Auth::Identity::LoginName, valueText(AdminLoginField));
-			Database::Handler::getPasswordService().updatePassword(authUser, valueText(PasswordField));
-
+			Database::User::pointer user {LmsApp->getDbSession().createUser(valueText(AdminLoginField).toUTF8(), valueText(PasswordField).toUTF8())};
 			user.modify()->setType(Database::User::Type::ADMIN);
 		}
 
@@ -81,7 +74,7 @@ class InitWizardModel : public Wt::WFormModel
 				if (!valueText(PasswordField).empty())
 				{
 					// Evaluate the strength of the password
-					auto res = Database::Handler::getPasswordService().strengthValidator()->evaluateStrength(valueText(PasswordField),
+					auto res = Database::Session::getPasswordService().strengthValidator()->evaluateStrength(valueText(PasswordField),
 								valueText(AdminLoginField), "");
 
 					if (!res.isValid())

src/ui/admin/UserView.cpp

@@ -78,17 +78,16 @@ class UserModel : public Wt::WFormModel
 
 		void saveData()
 		{
-			Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+			auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
 
 			if (_userId)
 			{
 				// Update user
-				Wt::Auth::User authUser = LmsApp->getDb().getUserDatabase().findWithId( std::to_string(*_userId) );
-				Database::User::pointer user = LmsApp->getDb().getUser( authUser );
+				Database::User::pointer user {Database::User::getById(LmsApp->getDbSession(), *_userId)};
 
 				// Account
 				if (!valueText(PasswordField).empty())
-					Database::Handler::getPasswordService().updatePassword(authUser, valueText(PasswordField));
+					LmsApp->getDbSession().updateUserPassword(user, valueText(PasswordField).toUTF8());
 
 				auto transcodeBitrateLimitRow {_bitrateModel->getRowFromString(valueText(AudioTranscodeBitrateLimitField))};
 				if (transcodeBitrateLimitRow)
@@ -97,12 +96,7 @@ class UserModel : public Wt::WFormModel
 			else
 			{
 				// Create user
-				Wt::Auth::User authUser = LmsApp->getDb().getUserDatabase().registerNew();
-				Database::User::pointer user = LmsApp->getDb().createUser(authUser);
-
-				// Account
-				authUser.setIdentity(Wt::Auth::Identity::LoginName, valueText(LoginField));
-				Database::Handler::getPasswordService().updatePassword(authUser, valueText(PasswordField));
+				Database::User::pointer user = LmsApp->getDbSession().createUser(valueText(LoginField).toUTF8(), valueText(PasswordField).toUTF8());
 
 				auto transcodeBitrateLimitRow {_bitrateModel->getRowFromString(valueText(AudioTranscodeBitrateLimitField))};
 				if (transcodeBitrateLimitRow )
@@ -120,11 +114,9 @@ class UserModel : public Wt::WFormModel
 			if (!_userId)
 				return;
 
-			Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
-
-			auto authUser {LmsApp->getDb().getUserDatabase().findWithId( std::to_string(*_userId) )};
-			auto user {LmsApp->getDb().getUser(authUser)};
+			auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
+			const Database::User::pointer user {Database::User::getById(LmsApp->getDbSession(), *_userId)};
 			if (user == LmsApp->getUser())
 				throw LmsException("Cannot edit ourselves");
 
@@ -133,12 +125,14 @@ class UserModel : public Wt::WFormModel
 				setValue(AudioTranscodeBitrateLimitField, _bitrateModel->getString(*transcodeBitrateLimitRow));
 		}
 
-		Wt::WString getLogin() const
+		Wt::WString getLoginName() const
 		{
 			if (_userId)
 			{
-				auto authUser = LmsApp->getDb().getUserDatabase().findWithId( std::to_string(*_userId) );
-				return authUser.identity(Wt::Auth::Identity::LoginName);
+				auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+
+				const Database::User::pointer user {Database::User::getById(LmsApp->getDbSession(), *_userId)};
+				return LmsApp->getDbSession().getUserLoginName(user);
 			}
 			else
 				return valueText(LoginField);
@@ -150,8 +144,8 @@ class UserModel : public Wt::WFormModel
 
 			if (field == LoginField)
 			{
-				auto user = LmsApp->getDb().getUserDatabase().findWithIdentity(Wt::Auth::Identity::LoginName, valueText(LoginField));
-				if (user.isValid())
+				const Database::User::pointer user {LmsApp->getDbSession().getUser(valueText(LoginField).toUTF8())};
+				if (user)
 					error = Wt::WString::tr("Lms.Admin.User.user-already-exists");
 			}
 			else if (field == PasswordField)
@@ -161,13 +155,13 @@ class UserModel : public Wt::WFormModel
 					if (Wt::asNumber(value(DemoField)))
 					{
 						//Demo account: password must be the same as the login name
-						if (valueText(PasswordField) != getLogin())
+						if (valueText(PasswordField) != getLoginName())
 							error = Wt::WString::tr("Lms.Admin.User.demo-password-invalid");
 					}
 					else
 					{
 						// Evaluate the strength of the password for non demo accounts
-						auto res = Database::Handler::getPasswordService().strengthValidator()->evaluateStrength(valueText(PasswordField), getLogin(), "");
+						auto res = Database::Session::getPasswordService().strengthValidator()->evaluateStrength(valueText(PasswordField), getLoginName(), "");
 
 						if (!res.isValid())
 							error = res.message();
@@ -176,9 +170,9 @@ class UserModel : public Wt::WFormModel
 			}
 			else if (field == DemoField)
 			{
-				Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+				auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-				if (Wt::asNumber(value(DemoField)) && Database::User::getDemo(LmsApp->getDboSession()))
+				if (Wt::asNumber(value(DemoField)) && Database::User::getDemo(LmsApp->getDbSession()))
 					error = Wt::WString::tr("Lms.Admin.User.demo-account-already-exists");
 			}
 
@@ -226,23 +220,23 @@ UserView::refreshView()
 
 	auto userId = readAs<Database::IdType>(wApp->internalPathNextPart("/admin/user/"));
 
-	LMS_LOG(UI, DEBUG) << "userId = " << (userId ? std::to_string(*userId) : "none");
-
 	clear();
 
-	Wt::WTemplateFormView* t = addNew<Wt::WTemplateFormView>(Wt::WString::tr("Lms.Admin.User.template"));
+	Wt::WTemplateFormView* t {addNew<Wt::WTemplateFormView>(Wt::WString::tr("Lms.Admin.User.template"))};
 
-	auto model = std::make_shared<UserModel>(userId);
+	auto model {std::make_shared<UserModel>(userId)};
 
 	if (userId)
 	{
-		auto authUser = LmsApp->getDb().getUserDatabase().findWithId( std::to_string(*userId) );
-		auto name = authUser.identity(Wt::Auth::Identity::LoginName);
-		t->bindString("title", Wt::WString::tr("Lms.Admin.User.user-edit").arg(name), Wt::TextFormat::Plain);
+		auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+
+		const Database::User::pointer user {Database::User::getById(LmsApp->getDbSession(), *userId)};
+		const std::string loginName {LmsApp->getDbSession().getUserLoginName(user)};
+		t->bindString("title", Wt::WString::tr("Lms.Admin.User.user-edit").arg(loginName), Wt::TextFormat::Plain);
 		t->setCondition("if-has-last-login-attempt", true);
 
-		Wt::WLineEdit *lastLoginAttempt = t->bindNew<Wt::WLineEdit>("last-login-attempt");
-		lastLoginAttempt->setText(authUser.lastLoginAttempt().toString());
+		Wt::WLineEdit *lastLoginAttempt {t->bindNew<Wt::WLineEdit>("last-login-attempt")};
+		lastLoginAttempt->setText(LmsApp->getDbSession().getUserLastLoginAttempt(user).toString());
 		lastLoginAttempt->setEnabled(false);
 	}
 	else

src/ui/admin/UsersView.cpp

@@ -59,22 +59,16 @@ UsersView::refreshView()
 
 	_container->clear();
 
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	auto users = Database::User::getAll(LmsApp->getDboSession());
-	for (auto user : users)
+	auto users = Database::User::getAll(LmsApp->getDbSession());
+	for (const auto& user : users)
 	{
-		auto userId = std::to_string(user.id());
-		Wt::WTemplate* entry = _container->addNew<Wt::WTemplate>(Wt::WString::tr("Lms.Admin.Users.template.entry"));
+		const Database::IdType userId {user.id()};
 
-		Wt::Auth::User authUser = LmsApp->getDb().getUserDatabase().findWithId(userId);
-		if (!authUser.isValid()) {
-			LMS_LOG(UI, ERROR) << "Skipping invalid userId = " << user.id();
-			continue;
-		}
+		Wt::WTemplate* entry {_container->addNew<Wt::WTemplate>(Wt::WString::tr("Lms.Admin.Users.template.entry"))};
 
-		auto login = authUser.identity(Wt::Auth::Identity::LoginName);
-		entry->bindString("name", login, Wt::TextFormat::Plain);
+		entry->bindString("name", LmsApp->getDbSession().getUserLoginName(user), Wt::TextFormat::Plain);
 
 		// Create tag
 		if (user->isAdmin() || user->isDemo())
@@ -106,16 +100,18 @@ UsersView::refreshView()
 			{
 				if (btn == Wt::StandardButton::Yes)
 				{
-					Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+					auto transaction {LmsApp->getDbSession().createUniqueTransaction()};
+
+					Database::User::pointer user {Database::User::getById(LmsApp->getDbSession(), userId)};
+					if (user)
+						LmsApp->getDbSession().removeUser(user);
 
-					auto authUser = LmsApp->getDb().getUserDatabase().findWithId(userId);
-					auto user = LmsApp->getDb().getUser(authUser);
-					LmsApp->getDb().getUserDatabase().deleteUser( authUser );
-					user.remove();
 					_container->removeWidget(entry);
 				}
 				else
+				{
 					delBtn->removeChild(msgBox);
+				}
 			});
 
 			msgBox->show();

src/ui/explore/ArtistInfoView.cpp

@@ -63,21 +63,18 @@ ArtistInfo::refresh()
 	if (!artistId)
 		return;
 
-	auto artistsIds = getService<Similarity::Searcher>()->getSimilarArtists(LmsApp->getDboSession(), *artistId, 5);
+	const std::vector<Database::IdType> artistsIds {getService<Similarity::Searcher>()->getSimilarArtists(LmsApp->getDbSession(), *artistId, 5)};
 
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	std::vector<Database::Artist::pointer> artists;
-	for (auto artistId : artistsIds)
+	for (Database::IdType artistId : artistsIds)
 	{
-		auto artist = Database::Artist::getById(LmsApp->getDboSession(), artistId);
+		Database::Artist::pointer artist {Database::Artist::getById(LmsApp->getDbSession(), artistId)};
+		if (!artist)
+			continue;
 
-		if (artist)
-			artists.push_back(artist);
-	}
-
-	for (auto artist : artists)
 		_similarArtistsContainer->addNew<ArtistLink>(artist);
+	}
 }
 
 } // namespace UserInterface

src/ui/explore/ArtistView.cpp

@@ -66,22 +66,22 @@ Artist::refresh()
 	if (!artistId)
 		return;
 
-        Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-	auto artist = Database::Artist::getById(LmsApp->getDboSession(), *artistId);
+        auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
+	const Database::Artist::pointer artist = Database::Artist::getById(LmsApp->getDbSession(), *artistId);
 	if (!artist)
 	{
 		LmsApp->goHome();
 		return;
 	}
 
-	Wt::WTemplate* t = addNew<Wt::WTemplate>(Wt::WString::tr("Lms.Explore.Artist.template"));
+	Wt::WTemplate* t {addNew<Wt::WTemplate>(Wt::WString::tr("Lms.Explore.Artist.template"))};
 	t->addFunction("tr", &Wt::WTemplate::Functions::tr);
 
 	Wt::WContainerWidget* clusterContainers = t->bindNew<Wt::WContainerWidget>("clusters");
 
 	{
-		auto clusterTypes = ScanSettings::get(LmsApp->getDboSession())->getClusterTypes();
+		auto clusterTypes = ScanSettings::get(LmsApp->getDbSession())->getClusterTypes();
 		auto clusterGroups = artist->getClusterGroups(clusterTypes, 3);
 
 		for (auto clusters : clusterGroups)

src/ui/explore/ArtistsInfoView.cpp

@@ -58,22 +58,23 @@ ArtistsInfo::refreshRecentlyAdded()
 {
 	auto after = Wt::WLocalDateTime::currentServerDateTime().toUTC().addMonths(-1);
 
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-	auto artists = Artist::getLastAdded(LmsApp->getDboSession(), after, 5);
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+	const std::vector<Database::Artist::pointer> artists {Artist::getLastAdded(LmsApp->getDbSession(), after, 5)};
 
 	_recentlyAddedContainer->clear();
-	for (auto artist : artists)
+	for (const Database::Artist::pointer& artist : artists)
 		_recentlyAddedContainer->addNew<ArtistLink>(artist);
 }
 
 void
 ArtistsInfo::refreshMostPlayed()
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-	auto artists = LmsApp->getUser()->getPlayedTrackList()->getTopArtists(5);
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+
+	const std::vector<Database::Artist::pointer> artists {LmsApp->getUser()->getPlayedTrackList(LmsApp->getDbSession())->getTopArtists(5)};
 
 	_mostPlayedContainer->clear();
-	for (auto artist : artists)
+	for (const Database::Artist::pointer& artist : artists)
 		_mostPlayedContainer->addNew<ArtistLink>(artist);
 }
 

src/ui/explore/ArtistsView.cpp

@@ -73,17 +73,17 @@ Artists::addSome()
 
 	auto clusterIds = _filters->getClusterIds();
 
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	bool moreResults;
-	auto artists = Artist::getByFilter(LmsApp->getDboSession(),
+	bool moreResults {};
+	const std::vector<Artist::pointer> artists {Artist::getByFilter(LmsApp->getDbSession(),
 			clusterIds,
 			searchKeywords,
-			_container->count(), 20, moreResults);
+			_container->count(), 20, moreResults)};
 
-	for (auto artist : artists)
+	for (const auto& artist : artists)
 	{
-		Wt::WTemplate* entry = _container->addNew<Wt::WTemplate>(Wt::WString::tr("Lms.Explore.Artists.template.entry"));
+		Wt::WTemplate* entry {_container->addNew<Wt::WTemplate>(Wt::WString::tr("Lms.Explore.Artists.template.entry"))};
 
 		entry->bindWidget("name", LmsApplication::createArtistAnchor(artist));
 	}

src/ui/explore/Explore.cpp

@@ -25,6 +25,7 @@
 
 #include "database/Artist.hpp"
 #include "database/Release.hpp"
+#include "database/Track.hpp"
 #include "utils/Logger.hpp"
 
 #include "LmsApplication.hpp"
@@ -66,9 +67,7 @@ handleContentsPathChange(Wt::WStackedWidget* stack)
 		{ "/tracks",		IdxTracks },
 	};
 
-	LMS_LOG(UI, DEBUG) << "Internal path changed to '" << wApp->internalPath() << "'";
-
-	for (auto index : indexes)
+	for (const auto& index : indexes)
 	{
 		if (wApp->internalPathMatches(index.first))
 		{
@@ -182,102 +181,104 @@ Explore::Explore()
 	handleInfoPathChange(infoStack);
 }
 
-// TODO SQL this?
-static std::vector<Database::Track::pointer> getArtistTracks(Wt::Dbo::Session& session, Database::IdType artistId, std::set<Database::IdType> clusters)
+static
+std::vector<Database::IdType>
+getArtistTracks(Database::Session& session, Database::IdType artistId, const std::set<Database::IdType>& clusters)
 {
-	std::vector<Database::Track::pointer> res;
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	auto artist = Database::Artist::getById(session, artistId);
+	Database::Artist::pointer artist {Database::Artist::getById(session, artistId)};
 	if (!artist)
-		return res;
+		return {};
 
-	res = artist->getTracks();
+	// TODO handle clusters here
+	const std::vector<Database::Track::pointer> tracks {artist->getTracks()};
 
+	std::vector<Database::IdType> res;
+	res.reserve(tracks.size());
+
+	std::transform(std::cbegin(tracks), std::cend(tracks), std::back_inserter(res), [](const Database::Track::pointer& track) { return track.id(); });
 	return res;
 }
 
-static std::vector<Database::Track::pointer> getReleaseTracks(Wt::Dbo::Session& session, Database::IdType releaseId, std::set<Database::IdType> clusters)
+static
+std::vector<Database::IdType>
+getReleaseTracks(Database::Session& session, Database::IdType releaseId, std::set<Database::IdType> clusters)
 {
-	std::vector<Database::Track::pointer> res;
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	auto release = Database::Release::getById(session, releaseId);
+	Database::Release::pointer release {Database::Release::getById(session, releaseId)};
 	if (!release)
-		return res;
+		return {};
 
-	res = release->getTracks(clusters);
+	const std::vector<Database::Track::pointer> tracks {release->getTracks(clusters)};
 
+	std::vector<Database::IdType> res;
+	res.reserve(tracks.size());
+
+	std::transform(std::cbegin(tracks), std::cend(tracks), std::back_inserter(res), [](const Database::Track::pointer& track) { return track.id(); });
 	return res;
 }
 
-static std::vector<Database::Track::pointer> getTrack(Wt::Dbo::Session& session, Database::IdType trackId)
+static
+std::vector<Database::IdType>
+getTrack(Database::Session& session, Database::IdType trackId)
 {
-	std::vector<Database::Track::pointer> res;
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	auto track = Database::Track::getById(session, trackId);
-	if (track)
-		res.push_back(track);
+	Database::Track::pointer track {Database::Track::getById(session, trackId)};
+	if (!track)
+		return {};
 
-	return res;
+	return {track.id()};
 }
 
 void
 Explore::handleArtistAdd(Database::IdType id)
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-
-	tracksAdd.emit(getArtistTracks(LmsApp->getDboSession(), id, _filters->getClusterIds()));
+	tracksAdd.emit(getArtistTracks(LmsApp->getDbSession(), id, _filters->getClusterIds()));
 }
 
 void
 Explore::handleArtistPlay(Database::IdType id)
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-
-	tracksPlay.emit(getArtistTracks(LmsApp->getDboSession(), id, _filters->getClusterIds()));
+	tracksPlay.emit(getArtistTracks(LmsApp->getDbSession(), id, _filters->getClusterIds()));
 }
 
 void
 Explore::handleReleaseAdd(Database::IdType id)
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-
-	tracksAdd.emit(getReleaseTracks(LmsApp->getDboSession(), id, _filters->getClusterIds()));
+	tracksAdd.emit(getReleaseTracks(LmsApp->getDbSession(), id, _filters->getClusterIds()));
 }
 
 void
 Explore::handleReleasePlay(Database::IdType id)
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-
-	tracksPlay.emit(getReleaseTracks(LmsApp->getDboSession(), id, _filters->getClusterIds()));
+	tracksPlay.emit(getReleaseTracks(LmsApp->getDbSession(), id, _filters->getClusterIds()));
 }
 
 void
 Explore::handleTrackAdd(Database::IdType id)
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-
-	tracksAdd.emit(getTrack(LmsApp->getDboSession(), id));
+	tracksAdd.emit(getTrack(LmsApp->getDbSession(), id));
 }
 
 void
 Explore::handleTrackPlay(Database::IdType id)
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-
-	tracksPlay.emit(getTrack(LmsApp->getDboSession(), id));
+	tracksPlay.emit(getTrack(LmsApp->getDbSession(), id));
 }
 
 void
-Explore::handleTracksAdd(std::vector<Database::Track::pointer> tracks)
+Explore::handleTracksAdd(const std::vector<Database::IdType>& trackIds)
 {
-	tracksAdd.emit(tracks);
+	tracksAdd.emit(trackIds);
 }
 
 void
-Explore::handleTracksPlay(std::vector<Database::Track::pointer> tracks)
+Explore::handleTracksPlay(const std::vector<Database::IdType>& trackIds)
 {
-	tracksPlay.emit(tracks);
+	tracksPlay.emit(trackIds);
 }
 
 } // namespace UserInterface

src/ui/explore/Explore.hpp

@@ -21,7 +21,6 @@
 
 #include <Wt/WTemplate.h>
 
-#include "database/Track.hpp"
 #include "database/Types.hpp"
 
 namespace UserInterface {
@@ -33,19 +32,19 @@ class Explore : public Wt::WTemplate
 	public:
 		Explore();
 
-		Wt::Signal<std::vector<Database::Track::pointer>> tracksAdd;
-		Wt::Signal<std::vector<Database::Track::pointer>> tracksPlay;
+		Wt::Signal<std::vector<Database::IdType>> tracksAdd;
+		Wt::Signal<std::vector<Database::IdType>> tracksPlay;
 
 	private:
 
-		void handleArtistAdd(Database::IdType id);
-		void handleArtistPlay(Database::IdType id);
-		void handleReleaseAdd(Database::IdType id);
-		void handleReleasePlay(Database::IdType id);
-		void handleTrackAdd(Database::IdType id);
-		void handleTrackPlay(Database::IdType id);
-		void handleTracksAdd(std::vector<Database::Track::pointer> tracks);
-		void handleTracksPlay(std::vector<Database::Track::pointer> tracks);
+		void handleArtistAdd(Database::IdType artistId);
+		void handleArtistPlay(Database::IdType artistId);
+		void handleReleaseAdd(Database::IdType releaseId);
+		void handleReleasePlay(Database::IdType releaseId);
+		void handleTrackAdd(Database::IdType trackId);
+		void handleTrackPlay(Database::IdType trackId);
+		void handleTracksAdd(const std::vector<Database::IdType>& trackIds);
+		void handleTracksPlay(const std::vector<Database::IdType>& trackIds);
 
 		Filters* _filters;
 };

src/ui/explore/Filters.cpp

@@ -49,43 +49,41 @@ Filters::showDialog()
 
 	// Populate data
 	{
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-		auto types = Database::ClusterType::getAll(LmsApp->getDboSession());
-
-		for (auto type : types)
+		const auto types {Database::ClusterType::getAll(LmsApp->getDbSession())};
+		for (const Database::ClusterType::pointer& type : types)
 			typeCombo->addItem(Wt::WString::fromUTF8(type->getName()));
 
 		if (!types.empty())
 		{
-			auto values = types.front()->getClusters();
+			const auto values {types.front()->getClusters()};
 
-			for (auto value : values)
+			for (const Database::Cluster::pointer& value : values)
 			{
 				if (_filterIds.find(value.id()) == _filterIds.end())
 					valueCombo->addItem(Wt::WString::fromUTF8(value->getName()));
 			}
 		}
-
 	}
 
-	typeCombo->changed().connect(std::bind([=]
+	typeCombo->changed().connect([=]
 	{
-		auto name = typeCombo->valueText().toUTF8();
+		const std::string name {typeCombo->valueText().toUTF8()};
 
 		valueCombo->clear();
 
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-		auto clusterType = Database::ClusterType::getByName(LmsApp->getDboSession(), name);
+		auto clusterType = Database::ClusterType::getByName(LmsApp->getDbSession(), name);
 
-		auto values = clusterType->getClusters();
-		for (auto value : values)
+		const auto values = clusterType->getClusters();
+		for (const Database::Cluster::pointer& value : values)
 		{
 			if (_filterIds.find(value.id()) == _filterIds.end())
 				valueCombo->addItem(Wt::WString::fromUTF8(value->getName()));
 		}
-	}));
+	});
 
 	dialog->setModal(true);
 	dialog->setMovable(false);
@@ -93,26 +91,26 @@ Filters::showDialog()
 	dialog->setResizable(false);
 	dialog->setClosable(false);
 
-	dialog->finished().connect(std::bind([=]
+	dialog->finished().connect([=]
 	{
 		if (dialog->result() != Wt::DialogCode::Accepted)
 			return;
 
-		auto type = typeCombo->valueText().toUTF8();
-		auto value = valueCombo->valueText().toUTF8();
+		const std::string type {typeCombo->valueText().toUTF8()};
+		const std::string value {valueCombo->valueText().toUTF8()};
 
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+		auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-		auto clusterType = Database::ClusterType::getByName(LmsApp->getDboSession(), type);
+		Database::ClusterType::pointer clusterType {Database::ClusterType::getByName(LmsApp->getDbSession(), type)};
 		if (!clusterType)
 			return;
 
-		auto cluster = clusterType->getCluster(value);
+		Database::Cluster::pointer cluster {clusterType->getCluster(value)};
 		if (!cluster)
 			return;
 
 		add(cluster.id());
-	}));
+	});
 
 	dialog->show();
 }
@@ -120,17 +118,17 @@ Filters::showDialog()
 void
 Filters::add(Database::IdType clusterId)
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	auto cluster = Database::Cluster::getById(LmsApp->getDboSession(), clusterId);
+	Database::Cluster::pointer cluster {Database::Cluster::getById(LmsApp->getDbSession(), clusterId)};
 	if (!cluster)
 		return;
 
-	auto res = _filterIds.insert(clusterId);
+	auto res {_filterIds.insert(clusterId)};
 	if (!res.second)
 		return;
 
-	auto filter = _filters->addWidget(LmsApp->createCluster(cluster, true));
+	auto filter {_filters->addWidget(LmsApp->createCluster(cluster, true))};
 	filter->clicked().connect(std::bind([=]
 	{
 		_filters->removeWidget(filter);

src/ui/explore/ReleaseInfoView.cpp

@@ -68,11 +68,11 @@ ReleaseInfo::refresh()
 	if (!releaseId)
 		return;
 
-	std::vector<Database::IdType> releasesIds {getService<Similarity::Searcher>()->getSimilarReleases(LmsApp->getDboSession(), *releaseId, 5)};
+	const std::vector<Database::IdType> releasesIds {getService<Similarity::Searcher>()->getSimilarReleases(LmsApp->getDbSession(), *releaseId, 5)};
 
-	Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	Database::Release::pointer release {Database::Release::getById(LmsApp->getDboSession(), *releaseId)};
+	Database::Release::pointer release {Database::Release::getById(LmsApp->getDbSession(), *releaseId)};
 	if (!release)
 		return;
 
@@ -102,13 +102,13 @@ ReleaseInfo::refresh()
 	std::vector<Database::Release::pointer> similarReleases;
 	for (Database::IdType id : releasesIds)
 	{
-		Database::Release::pointer similarRelease {Database::Release::getById(LmsApp->getDboSession(), id)};
+		Database::Release::pointer similarRelease {Database::Release::getById(LmsApp->getDbSession(), id)};
 
 		if (similarRelease)
 			similarReleases.emplace_back(similarRelease);
 	}
 
-	for (const auto& similarRelease : similarReleases)
+	for (const Database::Release::pointer& similarRelease : similarReleases)
 		_similarReleasesContainer->addNew<ReleaseLink>(similarRelease);
 }
 

src/ui/explore/ReleaseView.cpp

@@ -67,9 +67,9 @@ Release::refresh()
 	if (!releaseId)
 		return;
 
-        Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+        auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	auto release {Database::Release::getById(LmsApp->getDboSession(), *releaseId)};
+	const Database::Release::pointer release {Database::Release::getById(LmsApp->getDbSession(), *releaseId)};
 	if (!release)
 	{
 		LmsApp->goHome();
@@ -118,12 +118,12 @@ Release::refresh()
 
 	Wt::WContainerWidget* clusterContainers {t->bindNew<Wt::WContainerWidget>("clusters")};
 	{
-		auto clusterTypes {ScanSettings::get(LmsApp->getDboSession())->getClusterTypes()};
-		auto clusterGroups {release->getClusterGroups(clusterTypes, 3)};
+		const auto clusterTypes {ScanSettings::get(LmsApp->getDbSession())->getClusterTypes()};
+		const auto clusterGroups {release->getClusterGroups(clusterTypes, 3)};
 
-		for (auto clusters : clusterGroups)
+		for (const auto& clusters : clusterGroups)
 		{
-			for (auto cluster : clusters)
+			for (const auto& cluster : clusters)
 			{
 				auto clusterId {cluster.id()};
 				auto entry {clusterContainers->addWidget(LmsApp->createCluster(cluster))};

src/ui/explore/ReleasesInfoView.cpp

@@ -58,24 +58,24 @@ ReleasesInfo::refreshRecentlyAdded()
 {
 	auto after = Wt::WLocalDateTime::currentServerDateTime().toUTC().addMonths(-1);
 
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	auto releases {Release::getLastAdded(LmsApp->getDboSession(), after, 0, 5)};
+	const auto releases {Release::getLastAdded(LmsApp->getDbSession(), after, 0, 5)};
 
 	_recentlyAddedContainer->clear();
-	for (auto release : releases)
+	for (const Database::Release::pointer& release : releases)
 		_recentlyAddedContainer->addNew<ReleaseLink>(release);
 }
 
 void
 ReleasesInfo::refreshMostPlayed()
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-	auto releases = LmsApp->getUser()->getPlayedTrackList()->getTopReleases(5);
+	const auto releases {LmsApp->getUser()->getPlayedTrackList(LmsApp->getDbSession())->getTopReleases(5)};
 
 	_mostPlayedContainer->clear();
-	for (auto release : releases)
+	for (const Database::Release::pointer& release : releases)
 		_mostPlayedContainer->addNew<ReleaseLink>(release);
 }
 

src/ui/explore/ReleasesView.cpp

@@ -71,18 +71,17 @@ Releases::refresh()
 void
 Releases::addSome()
 {
-	auto searchKeywords = splitString(_search->text().toUTF8(), " ");
+	const auto searchKeywords {splitString(_search->text().toUTF8(), " ")};
+	const auto clusterIds {_filters->getClusterIds()};
 
-	auto clusterIds = _filters->getClusterIds();
-
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
 	bool moreResults;
-	auto releases = Release::getByFilter(LmsApp->getDboSession(), clusterIds, searchKeywords, _container->count(), 20, moreResults);
+	const auto releases {Release::getByFilter(LmsApp->getDbSession(), clusterIds, searchKeywords, _container->count(), 20, moreResults)};
 
-	for (auto release : releases)
+	for (const Database::Release::pointer& release : releases)
 	{
-		auto releaseId = release.id();
+		const Database::IdType releaseId {release.id()};
 
 		Wt::WTemplate* entry = _container->addNew<Wt::WTemplate>(Wt::WString::tr("Lms.Explore.Releases.template.entry"));
 		entry->addFunction("tr", Wt::WTemplate::Functions::tr);

src/ui/explore/TracksInfoView.cpp

@@ -74,10 +74,10 @@ TracksInfo::TracksInfo()
 void
 TracksInfo::refreshRecentlyAdded()
 {
-	auto after = Wt::WLocalDateTime::currentServerDateTime().toUTC().addMonths(-1);
+	const auto after {Wt::WLocalDateTime::currentServerDateTime().toUTC().addMonths(-1)};
 
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-	auto tracks = Track::getLastAdded(LmsApp->getDboSession(), after, 5);
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+	const auto tracks {Track::getLastAdded(LmsApp->getDbSession(), after, 5)};
 
 	_recentlyAddedContainer->clear();
 	addEntries(_recentlyAddedContainer, tracks);
@@ -86,8 +86,8 @@ TracksInfo::refreshRecentlyAdded()
 void
 TracksInfo::refreshMostPlayed()
 {
-	Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-	auto tracks = LmsApp->getUser()->getPlayedTrackList()->getTopTracks(5);
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+	const auto tracks {LmsApp->getUser()->getPlayedTrackList(LmsApp->getDbSession())->getTopTracks(5)};
 
 	_mostPlayedContainer->clear();
 	addEntries(_mostPlayedContainer, tracks);

src/ui/explore/TracksView.cpp

@@ -52,14 +52,12 @@ _filters(filters)
 	Wt::WText* playBtn = bindNew<Wt::WText>("play-btn", Wt::WString::tr("Lms.Explore.template.play-btn"), Wt::TextFormat::XHTML);
 	playBtn->clicked().connect(std::bind([=]
 	{
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
 		tracksPlay.emit(getTracks());
 	}));
 
 	Wt::WText* addBtn = bindNew<Wt::WText>("add-btn", Wt::WString::tr("Lms.Explore.template.add-btn"), Wt::TextFormat::XHTML);
 	addBtn->clicked().connect(std::bind([=]
 	{
-		Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
 		tracksAdd.emit(getTracks());
 	}));
 
@@ -76,18 +74,24 @@ _filters(filters)
 	filters->updated().connect(this, &Tracks::refresh);
 }
 
-std::vector<Database::Track::pointer>
+std::vector<Database::IdType>
 Tracks::getTracks(boost::optional<std::size_t> offset, boost::optional<std::size_t> size, bool& moreResults)
 {
-	auto searchKeywords {splitString(_search->text().toUTF8(), " ")};
-	auto clusterIds {_filters->getClusterIds()};
+	const auto searchKeywords {splitString(_search->text().toUTF8(), " ")};
+	const auto clusterIds {_filters->getClusterIds()};
 
-	Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
+	auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+
+	const auto tracks {Track::getByFilter(LmsApp->getDbSession(), clusterIds, searchKeywords, offset, size, moreResults)};
+	std::vector<Database::IdType> res;
+	res.reserve(tracks.size());
+	std::transform(std::cbegin(tracks), std::cend(tracks), std::back_inserter(res), [](const Database::Track::pointer& track) { return track.id(); });
+
+	return res;
 
-	return Track::getByFilter(LmsApp->getDboSession(), clusterIds, searchKeywords, offset, size, moreResults);
 }
 
-std::vector<Database::Track::pointer>
+std::vector<Database::IdType>
 Tracks::getTracks()
 {
 	bool moreResults;
@@ -104,14 +108,15 @@ Tracks::refresh()
 void
 Tracks::addSome()
 {
-	Wt::Dbo::Transaction transaction {LmsApp->getDboSession()};
-
 	bool moreResults;
-	auto tracks {getTracks(_tracksContainer->count(), 20, moreResults)};
+	const std::vector<Database::IdType> trackIds {getTracks(_tracksContainer->count(), 20, moreResults)};
 
-	for (auto track : tracks)
+	for (const Database::IdType trackId : trackIds)
 	{
-		auto trackId {track.id()};
+		auto transaction {LmsApp->getDbSession().createSharedTransaction()};
+
+		const Database::Track::pointer track {Database::Track::getById(LmsApp->getDbSession(), trackId)};
+
 		Wt::WTemplate* entry {_tracksContainer->addNew<Wt::WTemplate>(Wt::WString::tr("Lms.Explore.Tracks.template.entry"))};
 
 		entry->bindString("name", Wt::WString::fromUTF8(track->getName()), Wt::TextFormat::Plain);

src/ui/explore/TracksView.hpp

@@ -19,13 +19,14 @@
 
 #pragma once
 
+#include <boost/optional.hpp>
+
 #include <Wt/WContainerWidget.h>
 #include <Wt/WLineEdit.h>
 #include <Wt/WPushButton.h>
 #include <Wt/WTemplate.h>
 
 #include "database/Types.hpp"
-#include "database/Track.hpp"
 
 namespace UserInterface {
 
@@ -38,15 +39,15 @@ class Tracks : public Wt::WTemplate
 		Wt::Signal<Database::IdType> trackAdd;
 		Wt::Signal<Database::IdType> trackPlay;
 
-		Wt::Signal<std::vector<Database::Track::pointer>> tracksAdd;
-		Wt::Signal<std::vector<Database::Track::pointer>> tracksPlay;
+		Wt::Signal<std::vector<Database::IdType>> tracksAdd;
+		Wt::Signal<std::vector<Database::IdType>> tracksPlay;
 
 	private:
 		void refresh();
 		void addSome();
 
-		std::vector<Database::Track::pointer> getTracks(boost::optional<std::size_t> offset, boost::optional<std::size_t> size, bool& moreResults);
-		std::vector<Database::Track::pointer> getTracks();
+		std::vector<Database::IdType> getTracks(boost::optional<std::size_t> offset, boost::optional<std::size_t> size, bool& moreResults);
+		std::vector<Database::IdType> getTracks();
 
 		Wt::WContainerWidget* _tracksContainer;
 		Wt::WPushButton* _showMore;

src/ui/resource/AudioResource.cpp

@@ -38,9 +38,7 @@ AudioResource:: ~AudioResource()
 std::string
 AudioResource::getUrl(Database::IdType trackId) const
 {
-	std::string res = url()+ "&trackid=" + std::to_string(trackId);
-
-	return res;
+	return url()+ "&trackid=" + std::to_string(trackId);
 }
 
 void
@@ -82,14 +80,12 @@ AudioResource::handleRequest(const Wt::Http::Request& request,
 			return;
 		}
 
-		// transactions are not thread safe
+		// DbSession are not thread safe
 		{
 			Wt::WApplication::UpdateLock lock(LmsApp);
+			auto transaction {LmsApp->getDbSession().createSharedTransaction()};
 
-			Wt::Dbo::Transaction transaction(LmsApp->getDboSession());
-
-			Database::Track::pointer track = Database::Track::getById(LmsApp->getDboSession(), trackId);
-
+			const Database::Track::pointer track {Database::Track::getById(LmsApp->getDbSession(), trackId)};
 			if (!track)
 			{
 				LMS_LOG(UI, ERROR) << "Missing track";

src/ui/resource/AudioResource.hpp

@@ -23,7 +23,6 @@
 
 #include "av/AvTranscoder.hpp"
 
-#include "database/DatabaseHandler.hpp"
 #include "database/Types.hpp"
 
 

src/ui/resource/ImageResource.cpp

@@ -65,7 +65,7 @@ ImageResource::handleRequest(const Wt::Http::Request& request, Wt::Http::Respons
 	if (!sizeStr)
 		return;
 
-	auto size = readAs<std::size_t>(*sizeStr);
+	const auto size {readAs<std::size_t>(*sizeStr)};
 	if (!size || *size > maxSize)
 		return;
 
@@ -73,26 +73,26 @@ ImageResource::handleRequest(const Wt::Http::Request& request, Wt::Http::Respons
 
 	if (trackIdStr)
 	{
-		auto trackId = readAs<Database::IdType>(*trackIdStr);
+		const auto trackId {readAs<Database::IdType>(*trackIdStr)};
 		if (!trackId)
 			return;
 
-		// transactions are not thread safe
+		// DbSession are not thread safe
 		{
-			Wt::WApplication::UpdateLock lock(LmsApp);
-			cover = getService<CoverArt::Grabber>()->getFromTrack(LmsApp->getDboSession(), *trackId, Image::Format::JPEG, *size);
+			Wt::WApplication::UpdateLock lock {LmsApp};
+			cover = getService<CoverArt::Grabber>()->getFromTrack(LmsApp->getDbSession(), *trackId, Image::Format::JPEG, *size);
 		}
 	}
 	else if (releaseIdStr)
 	{
-		auto releaseId = readAs<Database::IdType>(*releaseIdStr);
+		const auto releaseId {readAs<Database::IdType>(*releaseIdStr)};
 		if (!releaseId)
 			return;
 
-		// transactions are not thread safe
+		// DbSession are not thread safe
 		{
-			Wt::WApplication::UpdateLock lock(LmsApp);
-			cover = getService<CoverArt::Grabber>()->getFromRelease(LmsApp->getDboSession(), *releaseId, Image::Format::JPEG, *size);
+			Wt::WApplication::UpdateLock lock {LmsApp};
+			cover = getService<CoverArt::Grabber>()->getFromRelease(LmsApp->getDbSession(), *releaseId, Image::Format::JPEG, *size);
 		}
 	}
 	else

src/ui/resource/ImageResource.hpp

@@ -24,7 +24,6 @@
 
 #include <Wt/WResource.h>
 
-#include "database/DatabaseHandler.hpp"
 #include "database/Types.hpp"
 
 #include "image/Image.hpp"
@@ -35,7 +34,7 @@ namespace UserInterface {
 class ImageResource : public Wt::WResource
 {
 	public:
-		static const std::size_t maxSize = 512;
+		static const std::size_t maxSize {512};
 
 		~ImageResource();