fix another pass by reference

src/audio/signalinfo.h

@@ -19,13 +19,13 @@ class SignalInfo final {
   public:
     constexpr SignalInfo() = default;
     constexpr explicit SignalInfo(
-            OptionalSampleLayout sampleLayout)
+            const OptionalSampleLayout& sampleLayout)
             : m_sampleLayout(sampleLayout) {
     }
     SignalInfo(
             ChannelCount channelCount,
             SampleRate sampleRate,
-            OptionalSampleLayout sampleLayout = std::nullopt)
+            const OptionalSampleLayout& sampleLayout = std::nullopt)
             : m_channelCount(channelCount),
               m_sampleRate(sampleRate),
               m_sampleLayout(sampleLayout) {

src/controllers/controllerpreset.h

@@ -60,7 +60,7 @@ class ControllerPreset {
     }
 
     void setModuleFileInfo(QFileInfo fileInfo) {
-        m_moduleFileInfo = fileInfo;
+        m_moduleFileInfo = std::move(fileInfo);
     }
 
     QFileInfo moduleFileInfo() const {

src/controllers/engine/colormapperjsproxy.cpp

@@ -1,6 +1,6 @@
 #include "controllers/engine/colormapperjsproxy.h"
 
-ColorMapperJSProxy::ColorMapperJSProxy(QVariantMap availableColors)
+ColorMapperJSProxy::ColorMapperJSProxy(const QVariantMap& availableColors)
         : m_pColorMapper(nullptr) {
     QMap<QRgb, QVariant> qrgbMap;
     QVariantMap::const_iterator it;

src/controllers/engine/colormapperjsproxy.h

@@ -14,7 +14,7 @@ class ColorMapperJSProxy final : public QObject {
     // the ColorMapper constructor segfaults. QJSEngine converts a JS object to
     // a QVariantMap, so this constructor converts the QVariantMap to a
     // QMap<QRgb, QVariant>.
-    Q_INVOKABLE ColorMapperJSProxy(QVariantMap availableColors);
+    Q_INVOKABLE ColorMapperJSProxy(const QVariantMap& availableColors);
 
     // Mixxx would segfault without this if a script calls "new ColorMapper()"
     // This should not actually be used.

src/controllers/engine/controllerengine.cpp

@@ -240,7 +240,7 @@ void ControllerEngine::uninitializeScriptEngine() {
     }
 }
 
-void ControllerEngine::loadModule(QFileInfo moduleFileInfo) {
+void ControllerEngine::loadModule(const QFileInfo& moduleFileInfo) {
     // QFileInfo does not have a isValid/isEmpty/isNull method to check if it
     // actually contains a reference, so we check if the filePath is empty as a
     // workaround.
@@ -291,7 +291,7 @@ void ControllerEngine::loadModule(QFileInfo moduleFileInfo) {
 #endif
 }
 
-void ControllerEngine::handleInput(QByteArray data, mixxx::Duration timestamp) {
+void ControllerEngine::handleInput(const QByteArray& data, mixxx::Duration timestamp) {
     if (m_handleInputFunction.isCallable()) {
         QJSValueList args;
         args << byteArrayToScriptValue(data);
@@ -438,7 +438,8 @@ void ControllerEngine::throwJSError(const QString& message) {
 #endif
 }
 
-void ControllerEngine::showScriptExceptionDialog(QJSValue evaluationResult, bool bFatalError) {
+void ControllerEngine::showScriptExceptionDialog(
+        const QJSValue& evaluationResult, bool bFatalError) {
     VERIFY_OR_DEBUG_ASSERT(evaluationResult.isError()) {
         return;
     }
@@ -679,7 +680,7 @@ void ControllerEngine::log(const QString& message) {
 }
 
 QJSValue ControllerEngine::makeConnection(
-        const QString& group, const QString& name, const QJSValue callback) {
+        const QString& group, const QString& name, const QJSValue& callback) {
     VERIFY_OR_DEBUG_ASSERT(m_pScriptEngine != nullptr) {
         return QJSValue();
     }
@@ -714,7 +715,7 @@ QJSValue ControllerEngine::makeConnection(
     return QJSValue();
 }
 
-bool ControllerEngine::removeScriptConnection(const ScriptConnection connection) {
+bool ControllerEngine::removeScriptConnection(const ScriptConnection& connection) {
     ControlObjectScript* coScript = getControlObjectScript(connection.key.group,
             connection.key.item);
 
@@ -725,7 +726,7 @@ bool ControllerEngine::removeScriptConnection(const ScriptConnection connection)
     return coScript->removeScriptConnection(connection);
 }
 
-void ControllerEngine::triggerScriptConnection(const ScriptConnection connection) {
+void ControllerEngine::triggerScriptConnection(const ScriptConnection& connection) {
     VERIFY_OR_DEBUG_ASSERT(m_pScriptEngine) {
         return;
     }

src/controllers/engine/controllerengine.h

@@ -26,7 +26,7 @@ class ControllerEngine : public QObject {
     ControllerEngine(Controller* controller);
     virtual ~ControllerEngine();
 
-    void handleInput(QByteArray data, mixxx::Duration timestamp);
+    void handleInput(const QByteArray& data, mixxx::Duration timestamp);
 
     bool executeFunction(QJSValue functionObject, const QJSValueList& arguments);
     bool executeFunction(const QJSValue& functionObject, const QByteArray& data);
@@ -43,11 +43,11 @@ class ControllerEngine : public QObject {
 
     /// Shows a UI dialog notifying of a script evaluation error.
     /// Precondition: QJSValue.isError() == true
-    void showScriptExceptionDialog(QJSValue evaluationResult, bool bFatal = false);
+    void showScriptExceptionDialog(const QJSValue& evaluationResult, bool bFatal = false);
 
-    bool removeScriptConnection(const ScriptConnection conn);
+    bool removeScriptConnection(const ScriptConnection& conn);
     /// Execute a ScriptConnection's JS callback
-    void triggerScriptConnection(const ScriptConnection conn);
+    void triggerScriptConnection(const ScriptConnection& conn);
 
     inline void setTesting(bool testing) {
         m_bTesting = testing;
@@ -64,7 +64,7 @@ class ControllerEngine : public QObject {
     double getDefaultParameter(const QString& group, const QString& name);
     /// Connect a ControlObject's valueChanged() signal to a script callback function
     /// Returns to the script a ScriptConnectionJSProxy
-    QJSValue makeConnection(const QString& group, const QString& name, const QJSValue callback);
+    QJSValue makeConnection(const QString& group, const QString& name, const QJSValue& callback);
     /// DEPRECATED: Use makeConnection instead.
     QJSValue connectControl(const QString& group,
             const QString& name,
@@ -105,7 +105,7 @@ class ControllerEngine : public QObject {
     virtual void timerEvent(QTimerEvent* event);
 
   public slots:
-    void loadModule(QFileInfo moduleFileInfo);
+    void loadModule(const QFileInfo& moduleFileInfo);
     bool loadScriptFiles(const QList<ControllerPreset::ScriptFileInfo>& scripts);
     void initializeScripts(const QList<ControllerPreset::ScriptFileInfo>& scripts);
     void gracefulShutdown();

src/controllers/engine/controllerenginejsproxy.cpp

@@ -8,66 +8,100 @@ ControllerEngineJSProxy::ControllerEngineJSProxy(ControllerEngine* m_pEngine)
 ControllerEngineJSProxy::~ControllerEngineJSProxy() {
 }
 
-double ControllerEngineJSProxy::getValue(QString group, QString name) {
+double ControllerEngineJSProxy::getValue(
+        const QString& group,
+        const QString& name) {
     return m_pEngine->getValue(group, name);
 }
 
-void ControllerEngineJSProxy::setValue(QString group, QString name, double newValue) {
+void ControllerEngineJSProxy::setValue(
+        const QString& group,
+        const QString& name,
+        double newValue) {
     m_pEngine->setValue(group, name, newValue);
 }
 
-double ControllerEngineJSProxy::getParameter(QString group, QString name) {
+double ControllerEngineJSProxy::getParameter(
+        const QString& group,
+        const QString& name) {
     return m_pEngine->getParameter(group, name);
 }
 
-void ControllerEngineJSProxy::setParameter(QString group, QString name, double newValue) {
+void ControllerEngineJSProxy::setParameter(
+        const QString& group,
+        const QString& name,
+        double newValue) {
     m_pEngine->setParameter(group, name, newValue);
 }
 
-double ControllerEngineJSProxy::getParameterForValue(QString group,
-        QString name,
+double ControllerEngineJSProxy::getParameterForValue(
+        const QString& group,
+        const QString& name,
         double value) {
     return m_pEngine->getParameterForValue(group, name, value);
 }
 
-void ControllerEngineJSProxy::reset(QString group, QString name) {
+void ControllerEngineJSProxy::reset(
+        const QString& group,
+        const QString& name) {
     m_pEngine->reset(group, name);
 }
 
-double ControllerEngineJSProxy::getDefaultValue(QString group, QString name) {
+double ControllerEngineJSProxy::getDefaultValue(
+        const QString& group,
+        const QString& name) {
     return m_pEngine->getDefaultValue(group, name);
 }
 
-double ControllerEngineJSProxy::getDefaultParameter(QString group,
-        QString name) {
+double ControllerEngineJSProxy::getDefaultParameter(
+        const QString& group,
+        const QString& name) {
     return m_pEngine->getDefaultParameter(group, name);
 }
 
-QJSValue ControllerEngineJSProxy::makeConnection(QString group, QString name, const QJSValue callback) {
+QJSValue ControllerEngineJSProxy::makeConnection(
+        const QString& group,
+        const QString& name,
+        const QJSValue& callback) {
     return m_pEngine->makeConnection(group, name, callback);
 }
 
-QJSValue ControllerEngineJSProxy::connectControl(QString group, QString name, const QJSValue passedCallback, bool disconnect) {
+QJSValue ControllerEngineJSProxy::connectControl(
+        const QString& group,
+        const QString& name,
+        const QJSValue& passedCallback,
+        bool disconnect) {
     return m_pEngine->connectControl(group, name, passedCallback, disconnect);
 }
 
-void ControllerEngineJSProxy::trigger(QString group, QString name) {
+void ControllerEngineJSProxy::trigger(
+        const QString& group,
+        const QString& name) {
     m_pEngine->trigger(group, name);
 }
 
-void ControllerEngineJSProxy::log(QString message) {
+void ControllerEngineJSProxy::log(const QString& message) {
     m_pEngine->log(message);
 }
 
-int ControllerEngineJSProxy::beginTimer(int interval, QJSValue scriptCode, bool oneShot) {
+int ControllerEngineJSProxy::beginTimer(
+        int interval,
+        const QJSValue& scriptCode,
+        bool oneShot) {
     return m_pEngine->beginTimer(interval, scriptCode, oneShot);
 }
 
 void ControllerEngineJSProxy::stopTimer(int timerId) {
     m_pEngine->stopTimer(timerId);
 }
 
-void ControllerEngineJSProxy::scratchEnable(int deck, int intervalsPerRev, double rpm, double alpha, double beta, bool ramp) {
+void ControllerEngineJSProxy::scratchEnable(
+        int deck,
+        int intervalsPerRev,
+        double rpm,
+        double alpha,
+        double beta,
+        bool ramp) {
     m_pEngine->scratchEnable(deck, intervalsPerRev, rpm, alpha, beta, ramp);
 }
 
@@ -83,20 +117,32 @@ bool ControllerEngineJSProxy::isScratching(int deck) {
     return m_pEngine->isScratching(deck);
 }
 
-void ControllerEngineJSProxy::softTakeover(QString group, QString name, bool set) {
+void ControllerEngineJSProxy::softTakeover(
+        const QString& group,
+        const QString& name,
+        bool set) {
     m_pEngine->softTakeover(group, name, set);
 }
 
-void ControllerEngineJSProxy::softTakeoverIgnoreNextValue(QString group,
-        QString name) {
+void ControllerEngineJSProxy::softTakeoverIgnoreNextValue(
+        const QString& group,
+        const QString& name) {
     m_pEngine->softTakeoverIgnoreNextValue(group, name);
 }
 
-void ControllerEngineJSProxy::brake(int deck, bool activate, double factor, double rate) {
+void ControllerEngineJSProxy::brake(
+        int deck,
+        bool activate,
+        double factor,
+        double rate) {
     m_pEngine->brake(deck, activate, factor, rate);
 }
 
-void ControllerEngineJSProxy::spinback(int deck, bool activate, double factor, double rate) {
+void ControllerEngineJSProxy::spinback(
+        int deck,
+        bool activate,
+        double factor,
+        double rate) {
     m_pEngine->spinback(deck, activate, factor, rate);
 }
 

src/controllers/engine/controllerenginejsproxy.h

@@ -21,28 +21,34 @@ class ControllerEngineJSProxy : public QObject {
 
     virtual ~ControllerEngineJSProxy();
 
-    Q_INVOKABLE double getValue(QString group, QString name);
-    Q_INVOKABLE void setValue(QString group, QString name, double newValue);
-    Q_INVOKABLE double getParameter(QString group, QString name);
-    Q_INVOKABLE void setParameter(QString group, QString name, double newValue);
-    Q_INVOKABLE double getParameterForValue(QString group, QString name, double value);
-    Q_INVOKABLE void reset(QString group, QString name);
-    Q_INVOKABLE double getDefaultValue(QString group, QString name);
-    Q_INVOKABLE double getDefaultParameter(QString group, QString name);
-    Q_INVOKABLE QJSValue makeConnection(QString group, QString name, const QJSValue callback);
+    Q_INVOKABLE double getValue(const QString& group, const QString& name);
+    Q_INVOKABLE void setValue(const QString& group, const QString& name, double newValue);
+    Q_INVOKABLE double getParameter(const QString& group, const QString& name);
+    Q_INVOKABLE void setParameter(const QString& group, const QString& name, double newValue);
+    Q_INVOKABLE double getParameterForValue(
+            const QString& group, const QString& name, double value);
+    Q_INVOKABLE void reset(const QString& group, const QString& name);
+    Q_INVOKABLE double getDefaultValue(const QString& group, const QString& name);
+    Q_INVOKABLE double getDefaultParameter(const QString& group, const QString& name);
+    Q_INVOKABLE QJSValue makeConnection(const QString& group,
+            const QString& name,
+            const QJSValue& callback);
     // DEPRECATED: Use makeConnection instead.
-    Q_INVOKABLE QJSValue connectControl(QString group, QString name, const QJSValue passedCallback, bool disconnect = false);
+    Q_INVOKABLE QJSValue connectControl(const QString& group,
+            const QString& name,
+            const QJSValue& passedCallback,
+            bool disconnect = false);
     // Called indirectly by the objects returned by connectControl
-    Q_INVOKABLE void trigger(QString group, QString name);
-    Q_INVOKABLE void log(QString message);
-    Q_INVOKABLE int beginTimer(int interval, QJSValue scriptCode, bool oneShot = false);
+    Q_INVOKABLE void trigger(const QString& group, const QString& name);
+    Q_INVOKABLE void log(const QString& message);
+    Q_INVOKABLE int beginTimer(int interval, const QJSValue& scriptCode, bool oneShot = false);
     Q_INVOKABLE void stopTimer(int timerId);
     Q_INVOKABLE void scratchEnable(int deck, int intervalsPerRev, double rpm, double alpha, double beta, bool ramp = true);
     Q_INVOKABLE void scratchTick(int deck, int interval);
     Q_INVOKABLE void scratchDisable(int deck, bool ramp = true);
     Q_INVOKABLE bool isScratching(int deck);
-    Q_INVOKABLE void softTakeover(QString group, QString name, bool set);
-    Q_INVOKABLE void softTakeoverIgnoreNextValue(QString group, QString name);
+    Q_INVOKABLE void softTakeover(const QString& group, const QString& name, bool set);
+    Q_INVOKABLE void softTakeoverIgnoreNextValue(const QString& group, const QString& name);
     Q_INVOKABLE void brake(int deck, bool activate, double factor = 1.0, double rate = 1.0);
     Q_INVOKABLE void spinback(int deck, bool activate, double factor = 1.8, double rate = -10.0);
     Q_INVOKABLE void softStart(int deck, bool activate, double factor = 1.0);

src/controllers/midi/midicontroller.h

@@ -138,7 +138,7 @@ class MidiControllerJSProxy : public ControllerJSProxy {
         m_pMidiController->sendShortMsg(status, byte1, byte2);
     }
 
-    Q_INVOKABLE void sendSysexMsg(QList<int> data, unsigned int length = 0) {
+    Q_INVOKABLE void sendSysexMsg(const QList<int>& data, unsigned int length = 0) {
         m_pMidiController->sendSysexMsg(data, length);
     }
 

src/effects/effectsmanager.cpp

@@ -14,8 +14,8 @@
 #include "util/assert.h"
 
 namespace {
-const QString kEffectGroupSeparator = "_";
-const QString kGroupClose = "]";
+constexpr QChar kEffectGroupSeparator = '_';
+constexpr QChar kGroupClose = ']';
 const unsigned int kEffectMessagPipeFifoSize = 2048;
 } // anonymous namespace
 

src/library/dao/trackdao.cpp

@@ -606,7 +606,7 @@ bool insertTrackLibrary(
         const mixxx::BeatsPointer& pBeats,
         DbId trackLocationId,
         const TrackFile& trackFile,
-        QDateTime trackDateAdded) {
+        const QDateTime& trackDateAdded) {
     bindTrackLibraryValues(pTrackLibraryInsert, trackRecord, pBeats);
 
     if (!trackRecord.getDateAdded().isNull()) {
@@ -2169,7 +2169,7 @@ TrackFile TrackDAO::relocateCachedTrack(
 }
 
 bool TrackDAO::updatePlayCounterFromPlayedHistory(
-        const QSet<TrackId> trackIds) const {
+        const QSet<TrackId>& trackIds) const {
     // Update both timesplay and last_played_at according to the
     // corresponding aggregated properties from the played history,
     // i.e. COUNT for the number of times a track has been played

src/library/dao/trackdao.h

@@ -73,7 +73,7 @@ class TrackDAO : public QObject, public virtual DAO, public virtual GlobalTrackC
     /// Update the play counter properties according to the corresponding
     /// aggregated properties obtained from the played history.
     bool updatePlayCounterFromPlayedHistory(
-            const QSet<TrackId> trackIds) const;
+            const QSet<TrackId>& trackIds) const;
 
   signals:
     // Forwarded from Track object

src/library/trackset/crate/cratetablemodel.cpp

@@ -59,7 +59,7 @@ void CrateTableModel::selectCrate(CrateId crateId) {
     setDefaultSort(fieldIndex("artist"), Qt::AscendingOrder);
 }
 
-bool CrateTableModel::addTrack(const QModelIndex& index, QString location) {
+bool CrateTableModel::addTrack(const QModelIndex& index, const QString& location) {
     Q_UNUSED(index);
 
     // This will only succeed if the file actually exist.