Performance.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/20506

common/lset.cpp

@@ -569,7 +569,7 @@ const LSET& LSET::InternalCuMask()
 }
 
 
-LSET LSET::AllCuMask( int aCuLayerCount )
+LSET allCuMask( int aCuLayerCount )
 {
     LSET ret;
 
@@ -580,13 +580,39 @@ LSET LSET::AllCuMask( int aCuLayerCount )
 }
 
 
+LSET LSET::AllCuMask( int aCuLayerCount )
+{
+    static LSET savedMax = allCuMask( MAX_CU_LAYERS );
+    static LSET cache;
+    static int  cacheCuLayerCount = -1;
+
+    if( aCuLayerCount == MAX_CU_LAYERS )
+        return savedMax;
+
+    if( aCuLayerCount != cacheCuLayerCount )
+    {
+        cache = allCuMask( aCuLayerCount );
+        cacheCuLayerCount = aCuLayerCount;
+    }
+
+    return cache;
+}
+
+
+LSET allNonCuMask()
+{
+    LSET mask = LSET().set();
+
+    for( auto it = mask.copper_layers_begin(); it != mask.copper_layers_end(); ++it )
+        mask.reset( *it );
+
+    return mask;
+}
+
+
 LSET LSET::AllNonCuMask()
 {
-    LSET saved = LSET().set();
+    static LSET saved = allNonCuMask();
-
-    for( auto it = saved.copper_layers_begin(); it != saved.copper_layers_end(); ++it )
-        saved.reset( *it );
-
     return saved;
 }
 

eeschema/sch_item.cpp

@@ -474,8 +474,10 @@ int SCH_ITEM::compare( const SCH_ITEM& aOther, int aCompareFlags ) const
 
 const wxString& SCH_ITEM::GetDefaultFont() const
 {
+    static const char eeschema[] = "eeschema";
+
     SETTINGS_MANAGER&  mgr = Pgm().GetSettingsManager();
-    EESCHEMA_SETTINGS* cfg = mgr.GetAppSettings<EESCHEMA_SETTINGS>( "eeschema" );
+    EESCHEMA_SETTINGS* cfg = mgr.GetAppSettings<EESCHEMA_SETTINGS>( eeschema );
 
     return cfg->m_Appearance.default_font;
 }

pcbnew/pcb_base_frame.cpp

@@ -907,35 +907,41 @@ void PCB_BASE_FRAME::SaveSettings( APP_SETTINGS_BASE* aCfg )
 
 PCBNEW_SETTINGS* PCB_BASE_FRAME::GetPcbNewSettings() const
 {
-    return Pgm().GetSettingsManager().GetAppSettings<PCBNEW_SETTINGS>( "pcbnew" );
+    static const char pcbnew[] = "pcbnew";
+    return Pgm().GetSettingsManager().GetAppSettings<PCBNEW_SETTINGS>( pcbnew );
 }
 
 
 FOOTPRINT_EDITOR_SETTINGS* PCB_BASE_FRAME::GetFootprintEditorSettings() const
 {
-    return Pgm().GetSettingsManager().GetAppSettings<FOOTPRINT_EDITOR_SETTINGS>( "fpedit" );
+    static const char fpedit[] = "fpedit";
+    return Pgm().GetSettingsManager().GetAppSettings<FOOTPRINT_EDITOR_SETTINGS>( fpedit );
 }
 
 
 PCB_VIEWERS_SETTINGS_BASE* PCB_BASE_FRAME::GetViewerSettingsBase() const
 {
+    static const char pcbnew[] = "pcbnew";
+    static const char fpedit[] = "fpedit";
+    static const char cvpcb[] = "cvpcb";
+
     switch( GetFrameType() )
     {
     case FRAME_PCB_EDITOR:
     case FRAME_PCB_DISPLAY3D:
     default:
-        return Pgm().GetSettingsManager().GetAppSettings<PCBNEW_SETTINGS>( "pcbnew" );
+        return Pgm().GetSettingsManager().GetAppSettings<PCBNEW_SETTINGS>( pcbnew );
 
     case FRAME_FOOTPRINT_EDITOR:
     case FRAME_FOOTPRINT_WIZARD:
-        return Pgm().GetSettingsManager().GetAppSettings<FOOTPRINT_EDITOR_SETTINGS>( "fpedit" );
+        return Pgm().GetSettingsManager().GetAppSettings<FOOTPRINT_EDITOR_SETTINGS>( fpedit );
 
     case FRAME_FOOTPRINT_VIEWER:
     case FRAME_FOOTPRINT_CHOOSER:
     case FRAME_FOOTPRINT_PREVIEW:
     case FRAME_CVPCB:
     case FRAME_CVPCB_DISPLAY:
-        return Pgm().GetSettingsManager().GetAppSettings<CVPCB_SETTINGS>( "cvpcb" );
+        return Pgm().GetSettingsManager().GetAppSettings<CVPCB_SETTINGS>( cvpcb );
     }
 }
 

pcbnew/pcb_draw_panel_gal.cpp

@@ -464,7 +464,8 @@ void PCB_DRAW_PANEL_GAL::UpdateColors()
     }
     else
     {
-        auto* app = Pgm().GetSettingsManager().GetAppSettings<PCBNEW_SETTINGS>( "pcbnew" );
+        static const char pcbnew[] = "pcbnew";
+        PCBNEW_SETTINGS*  app = Pgm().GetSettingsManager().GetAppSettings<PCBNEW_SETTINGS>( pcbnew );
 
         if( app )
             cs = Pgm().GetSettingsManager().GetColorSettings( app->m_ColorTheme );

pcbnew/pcb_painter.cpp

@@ -83,23 +83,27 @@ PCBNEW_SETTINGS* pcbconfig()
 // returns the viewer options existing to Cvpcb and Pcbnew
 PCB_VIEWERS_SETTINGS_BASE* PCB_PAINTER::viewer_settings()
 {
+    static const char pcbnew[] = "pcbnew";
+    static const char fpedit[] = "fpedit";
+    static const char cvpcb[] = "cvpcb";
+
     switch( m_frameType )
     {
     case FRAME_PCB_EDITOR:
     case FRAME_PCB_DISPLAY3D:
     default:
-        return Pgm().GetSettingsManager().GetAppSettings<PCBNEW_SETTINGS>( "pcbnew" );
+        return Pgm().GetSettingsManager().GetAppSettings<PCBNEW_SETTINGS>( pcbnew );
 
     case FRAME_FOOTPRINT_EDITOR:
     case FRAME_FOOTPRINT_WIZARD:
-        return Pgm().GetSettingsManager().GetAppSettings<FOOTPRINT_EDITOR_SETTINGS>( "fpedit" );
+        return Pgm().GetSettingsManager().GetAppSettings<FOOTPRINT_EDITOR_SETTINGS>( fpedit );
 
     case FRAME_FOOTPRINT_VIEWER:
     case FRAME_FOOTPRINT_CHOOSER:
     case FRAME_FOOTPRINT_PREVIEW:
     case FRAME_CVPCB:
     case FRAME_CVPCB_DISPLAY:
-        return Pgm().GetSettingsManager().GetAppSettings<CVPCB_SETTINGS>( "cvpcb" );
+        return Pgm().GetSettingsManager().GetAppSettings<CVPCB_SETTINGS>( cvpcb );
     }
 }
 
@@ -1230,10 +1234,8 @@ void PCB_PAINTER::draw( const PCB_VIA* aVia, int aLayer )
 void PCB_PAINTER::draw( const PAD* aPad, int aLayer )
 {
     COLOR4D      color = m_pcbSettings.GetColor( aPad, aLayer );
-
     const int    copperLayer = IsPadCopperLayer( aLayer ) ? aLayer - LAYER_PAD_COPPER_START : aLayer;
-
+    PCB_LAYER_ID pcbLayer = static_cast<PCB_LAYER_ID>( copperLayer );
-    const PCB_LAYER_ID& pcbLayer = static_cast<PCB_LAYER_ID>( copperLayer );
 
     if( IsNetnameLayer( aLayer ) )
     {