From 64bf8d9d06213ebb24b9e04372dd410f69913064 Mon Sep 17 00:00:00 2001
From: ronso0 <ronso0@mixxx.org>
Date: Fri, 11 Nov 2022 11:28:23 +0100
Subject: [PATCH] Effect parameter: QHash for unit strings lookup

---
 .../backends/effectmanifestparameter.h        | 89 +++++++------------
 src/effects/backends/lv2/lv2manifest.cpp      |  2 +-
 2 files changed, 34 insertions(+), 57 deletions(-)

diff --git a/src/effects/backends/effectmanifestparameter.h b/src/effects/backends/effectmanifestparameter.h
index fb5ae555dc10..40f9ac007d11 100644
--- a/src/effects/backends/effectmanifestparameter.h
+++ b/src/effects/backends/effectmanifestparameter.h
@@ -123,59 +123,28 @@ class EffectManifestParameter {
         }
     }
 
-    static QString unitsHintToString(const UnitsHint unitsHint) {
-        switch (unitsHint) {
-        case UnitsHint::BPM:
-            return QStringLiteral("BPM");
-        case UnitsHint::Cent:
-            return QStringLiteral("ct");
-        case UnitsHint::Centimetre:
-            return QStringLiteral("cm");
-        case UnitsHint::Decibel:
-            return QStringLiteral("dB");
-        case UnitsHint::Degree:
-            return QStringLiteral("°");
-        case UnitsHint::Frame:
-            return QStringLiteral("f");
-        case UnitsHint::Hertz:
-            return QStringLiteral("Hz");
-        case UnitsHint::Inch:
-            return QStringLiteral("in");
-        case UnitsHint::KiloHertz:
-            return QStringLiteral("kHz");
-        case UnitsHint::Kilometer:
-            return QStringLiteral("km");
-        case UnitsHint::Meter:
-            return QStringLiteral("m");
-        case UnitsHint::MegaHertz:
-            return QStringLiteral("MHz");
-        case UnitsHint::Mile:
-            return QStringLiteral("mi");
-        case UnitsHint::Minute:
-            return QStringLiteral("min");
-        case UnitsHint::Millmeter:
-            return QStringLiteral("mm");
-        case UnitsHint::Millisecond:
-            return QStringLiteral("ms");
-        case UnitsHint::Octave:
-            return QStringLiteral("oct");
-        case UnitsHint::Percentage:
-            return QStringLiteral("%");
-        case UnitsHint::Seconds:
-            return QStringLiteral("s");
-        case UnitsHint::Semitone12tet:
-            return QStringLiteral("semi");
-        case UnitsHint::Unknown:
-        case UnitsHint::Beat:
-        case UnitsHint::Beats:
-        case UnitsHint::Bar:
-        case UnitsHint::Coefficient:
-        case UnitsHint::Midinote:
-        case UnitsHint::SampleRate:
-        default:
-            return QLatin1String("");
-        }
-    }
+    const QHash<UnitsHint, QString> unitsHintStringHash{
+            {UnitsHint::BPM, QString("BPM")},
+            {UnitsHint::Cent, QString("ct")},
+            {UnitsHint::Centimetre, QString("cm")},
+            {UnitsHint::Decibel, QString("dB")},
+            {UnitsHint::Degree, QString("°")},
+            {UnitsHint::Frame, QString("f")},
+            {UnitsHint::Hertz, QString("Hz")},
+            {UnitsHint::Inch, QString("in")},
+            {UnitsHint::KiloHertz, QString("kHz")},
+            {UnitsHint::Kilometer, QString("km")},
+            {UnitsHint::Meter, QString("m")},
+            {UnitsHint::MegaHertz, QString("MHz")},
+            {UnitsHint::Mile, QString("mi")},
+            {UnitsHint::Minute, QString("min")},
+            {UnitsHint::Millmeter, QString("mm")},
+            {UnitsHint::Millisecond, QString("ms")},
+            {UnitsHint::Octave, QString("oct")},
+            {UnitsHint::Percentage, QString("%")},
+            {UnitsHint::Seconds, QString("s")},
+            {UnitsHint::Semitone12tet, QString("semi")},
+    };
 
     // Custom units we do not want to use in effect widgets
     QSet<QString> customUnitsBlacklist = {
@@ -312,11 +281,12 @@ class EffectManifestParameter {
     UnitsHint unitsHint() const {
         return m_unitsHint;
     }
-    const QString unitString() const {
-        return unitsHintToString(m_unitsHint);
-    }
     void setUnitsHint(UnitsHint unitsHint) {
         m_unitsHint = unitsHint;
+        m_unitString = EffectManifestParameter::unitsHintStringHash.value(unitsHint);
+    }
+    const QString unitString() const {
+        return m_unitString;
     }
 
     LinkType defaultLinkType() const {
@@ -405,6 +375,7 @@ class EffectManifestParameter {
     ParameterType m_parameterType;
     ValueScaler m_valueScaler;
     UnitsHint m_unitsHint;
+    QString m_unitString;
     LinkType m_defaultLinkType;
     LinkInversion m_defaultLinkInversion;
     double m_neutralPointOnScale;
@@ -428,3 +399,9 @@ typedef EffectManifestParameter::ParameterType EffectParameterType;
 inline qhash_seed_t qHash(const EffectParameterType& parameterType) {
     return static_cast<qhash_seed_t>(parameterType);
 }
+
+typedef EffectManifestParameter::UnitsHint UnitsHint;
+
+inline qhash_seed_t qHash(const UnitsHint& uhint) {
+    return static_cast<qhash_seed_t>(uhint);
+}
diff --git a/src/effects/backends/lv2/lv2manifest.cpp b/src/effects/backends/lv2/lv2manifest.cpp
index 968f15eac9ff..bccf96b6aabb 100644
--- a/src/effects/backends/lv2/lv2manifest.cpp
+++ b/src/effects/backends/lv2/lv2manifest.cpp
@@ -92,7 +92,7 @@ LV2Manifest::LV2Manifest(LilvWorld* world,
                     if (customUnit) {
                         // Accepted custom units needs to be 'whitelisted' in
                         // EffectManifestParameter::lv2UnitToUnitsHint and added to
-                        // EffectManifestParameter::unitsHintToString
+                        // EffectManifestParameter::unitsHintStringHash
                         unitsHint = EffectManifestParameter::lv2UnitToUnitsHint(
                                 lilv_node_as_string(customUnit));
                         if (lv2ParamDebug &&