Pass non-trivial/large function args by reference

Fixes a bunch of `-Wclazy-function-args-by-ref` warnings. See
https://github.com/KDE/clazy/blob/master/docs/checks/README-function-args-by-ref.md
for details.

Most of these changes are automated, using the clazy fixit by setting
the `CLAZY_EXPORT_FIXES` before compilation and then running:

    $ mkdir /tmp/patch
    $ find ../src -iname "*.yaml" -exec mv {} /tmp/patch \;
    $ clang-apply-replacements /tmp/patch

8 files changed, 12 insertions, 10 deletions

diff --git a/src/analyzer/analyzerbeats.cpp b/src/analyzer/analyzerbeats.cpp
index 62b98115cb..67dd45d17f 100644
--- a/src/analyzer/analyzerbeats.cpp
+++ b/src/analyzer/analyzerbeats.cpp
@@ -293,7 +293,7 @@ void AnalyzerBeats::storeResults(TrackPointer tio) {
 
 // static
 QHash<QString, QString> AnalyzerBeats::getExtraVersionInfo(
-        QString pluginId, bool bPreferencesFastAnalysis) {
+        const QString& pluginId, bool bPreferencesFastAnalysis) {
     QHash<QString, QString> extraVersionInfo;
     extraVersionInfo["vamp_plugin_id"] = pluginId;
     if (bPreferencesFastAnalysis) {
diff --git a/src/analyzer/analyzerbeats.h b/src/analyzer/analyzerbeats.h
index 01b9098f28..e0667149e6 100644
--- a/src/analyzer/analyzerbeats.h
+++ b/src/analyzer/analyzerbeats.h
@@ -35,7 +35,7 @@ class AnalyzerBeats : public Analyzer {
   private:
     bool shouldAnalyze(TrackPointer tio) const;
     static QHash<QString, QString> getExtraVersionInfo(
-            QString pluginId, bool bPreferencesFastAnalysis);
+            const QString& pluginId, bool bPreferencesFastAnalysis);
 
     BeatDetectionSettings m_bpmSettings;
     std::unique_ptr<mixxx::AnalyzerBeatsPlugin> m_pPlugin;
diff --git a/src/analyzer/analyzerkey.cpp b/src/analyzer/analyzerkey.cpp
index fc9bb3ee09..a11f711525 100644
--- a/src/analyzer/analyzerkey.cpp
+++ b/src/analyzer/analyzerkey.cpp
@@ -30,7 +30,7 @@ mixxx::AnalyzerPluginInfo AnalyzerKey::defaultPlugin() {
     return plugins.at(0);
 }
 
-AnalyzerKey::AnalyzerKey(KeyDetectionSettings keySettings)
+AnalyzerKey::AnalyzerKey(const KeyDetectionSettings& keySettings)
         : m_keySettings(keySettings),
           m_iSampleRate(0),
           m_iTotalSamples(0),
@@ -185,7 +185,7 @@ void AnalyzerKey::storeResults(TrackPointer tio) {
 
 // static
 QHash<QString, QString> AnalyzerKey::getExtraVersionInfo(
-        QString pluginId, bool bPreferencesFastAnalysis) {
+        const QString& pluginId, bool bPreferencesFastAnalysis) {
     QHash<QString, QString> extraVersionInfo;
     extraVersionInfo["vamp_plugin_id"] = pluginId;
     if (bPreferencesFastAnalysis) {
diff --git a/src/analyzer/analyzerkey.h b/src/analyzer/analyzerkey.h
index 52ba45b88b..b25fec8b07 100644
--- a/src/analyzer/analyzerkey.h
+++ b/src/analyzer/analyzerkey.h
@@ -14,7 +14,7 @@
 
 class AnalyzerKey : public Analyzer {
   public:
-    explicit AnalyzerKey(KeyDetectionSettings keySettings);
+    explicit AnalyzerKey(const KeyDetectionSettings& keySettings);
     ~AnalyzerKey() override = default;
 
     static QList<mixxx::AnalyzerPluginInfo> availablePlugins();
@@ -27,7 +27,7 @@ class AnalyzerKey : public Analyzer {
 
   private:
     static QHash<QString, QString> getExtraVersionInfo(
-            QString pluginId, bool bPreferencesFastAnalysis);
+            const QString& pluginId, bool bPreferencesFastAnalysis);
 
     bool shouldAnalyze(TrackPointer tio) const;
 
diff --git a/src/analyzer/analyzerwaveform.cpp b/src/analyzer/analyzerwaveform.cpp
index f7dba829fc..ec0a6a1b0f 100644
--- a/src/analyzer/analyzerwaveform.cpp
+++ b/src/analyzer/analyzerwaveform.cpp
@@ -16,7 +16,7 @@ mixxx::Logger kLogger("AnalyzerWaveform");
 
 AnalyzerWaveform::AnalyzerWaveform(
         UserSettingsPointer pConfig,
-        QSqlDatabase dbConnection)
+        const QSqlDatabase& dbConnection)
         : m_analysisDao(pConfig),
           m_waveformData(nullptr),
           m_waveformSummaryData(nullptr),
diff --git a/src/analyzer/analyzerwaveform.h b/src/analyzer/analyzerwaveform.h
index c12ccc3723..86b13f2c26 100644
--- a/src/analyzer/analyzerwaveform.h
+++ b/src/analyzer/analyzerwaveform.h
@@ -139,7 +139,7 @@ class AnalyzerWaveform : public Analyzer {
   public:
     AnalyzerWaveform(
             UserSettingsPointer pConfig,
-            QSqlDatabase dbConnection);
+            const QSqlDatabase& dbConnection);
     ~AnalyzerWaveform() override;
 
     bool initialize(TrackPointer tio, int sampleRate, int totalSamples) override;
diff --git a/src/analyzer/plugins/buffering_utils.cpp b/src/analyzer/plugins/buffering_utils.cpp
index 6edecb5ca4..680b792831 100644
--- a/src/analyzer/plugins/buffering_utils.cpp
+++ b/src/analyzer/plugins/buffering_utils.cpp
@@ -7,7 +7,9 @@
 
 namespace mixxx {
 
-bool DownmixAndOverlapHelper::initialize(size_t windowSize, size_t stepSize, WindowReadyCallback callback) {
+bool DownmixAndOverlapHelper::initialize(size_t windowSize,
+        size_t stepSize,
+        const WindowReadyCallback& callback) {
     m_buffer.assign(windowSize, 0.0);
     m_callback = callback;
     m_windowSize = windowSize;
diff --git a/src/analyzer/plugins/buffering_utils.h b/src/analyzer/plugins/buffering_utils.h
index 8e4ade0d4d..46598c3373 100644
--- a/src/analyzer/plugins/buffering_utils.h
+++ b/src/analyzer/plugins/buffering_utils.h
@@ -19,7 +19,7 @@ class DownmixAndOverlapHelper {
     bool initialize(
             size_t windowSize,
             size_t stepSize,
-            WindowReadyCallback callback);
+            const WindowReadyCallback& callback);
 
     bool processStereoSamples(
             const CSAMPLE* pInput,