Improve Bankswitch class efficiency by using string_view.

src/emucore/Bankswitch.cxx

@@ -20,13 +20,12 @@
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 string Bankswitch::typeToName(Bankswitch::Type type)
 {
-  return BSList[static_cast<int>(type)].name;
+  return string{BSList[static_cast<int>(type)].name};
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-Bankswitch::Type Bankswitch::nameToType(string_view n)  // FIXME: name
+Bankswitch::Type Bankswitch::nameToType(string_view name)
 {
-  string name{n};
   const auto it = ourNameToTypes.find(name);
   if(it != ourNameToTypes.end())
     return it->second;
@@ -37,17 +36,17 @@ Bankswitch::Type Bankswitch::nameToType(string_view n)  // FIXME: name
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 string Bankswitch::typeToDesc(Bankswitch::Type type)
 {
-  return BSList[static_cast<int>(type)].desc;
+  return string{BSList[static_cast<int>(type)].desc};
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Bankswitch::Type Bankswitch::typeFromExtension(const FSNode& file)
 {
-  const string& name = file.getPath();
+  const string_view name = file.getPath();
-  const string::size_type idx = name.find_last_of('.');
+  const auto idx = name.find_last_of('.');
-  if(idx != string::npos)
+  if(idx != string_view::npos)
   {
-    const auto it = ourExtensions.find(name.c_str() + idx + 1);
+    const auto it = ourExtensions.find(name.substr(idx + 1));
     if(it != ourExtensions.end())
       return it->second;
   }
@@ -56,12 +55,12 @@ Bankswitch::Type Bankswitch::typeFromExtension(const FSNode& file)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool Bankswitch::isValidRomName(const string& name, string& ext)
+bool Bankswitch::isValidRomName(string_view name, string& ext)
 {
-  const string::size_type idx = name.find_last_of('.');
+  const auto idx = name.find_last_of('.');
-  if(idx != string::npos)
+  if(idx != string_view::npos)
   {
-    const char* const e = name.c_str() + idx + 1;
+    const auto e = name.substr(idx + 1);
     const auto it = ourExtensions.find(e);
     if(it != ourExtensions.end())
     {
@@ -73,27 +72,7 @@ bool Bankswitch::isValidRomName(const string& name, string& ext)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool Bankswitch::isValidRomName(const FSNode& name, string& ext)
+constexpr std::array<Bankswitch::Description, static_cast<uInt32>(Bankswitch::Type::NumSchemes)>
-{
-  return isValidRomName(name.getPath(), ext);
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool Bankswitch::isValidRomName(const FSNode& name)
-{
-  string ext;  // extension not used
-  return isValidRomName(name.getPath(), ext);
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool Bankswitch::isValidRomName(const string& name)
-{
-  string ext;  // extension not used
-  return isValidRomName(name, ext);
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-constexpr std::array<Bankswitch::Description, static_cast<int>(Bankswitch::Type::NumSchemes)>
 Bankswitch::BSList = {{
   { "AUTO"    , "Auto-detect"                 },
   { "0840"    , "0840 (8K EconoBanking)"      },
@@ -154,8 +133,8 @@ Bankswitch::BSList = {{
 #endif
 }};
 
-#if defined(GUI_SUPPORT)
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-const std::array<Bankswitch::SizesType, static_cast<int>(Bankswitch::Type::NumSchemes)>
+const std::array<Bankswitch::SizesType, static_cast<uInt32>(Bankswitch::Type::NumSchemes)>
 Bankswitch::Sizes = {{
   { Bankswitch::any_KB, Bankswitch::any_KB }, // _AUTO
   {    8_KB,   8_KB }, // _0840
@@ -215,7 +194,6 @@ Bankswitch::Sizes = {{
   { Bankswitch::any_KB, Bankswitch::any_KB }
 #endif
 }};
-#endif  // GUI_SUPPORT
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Bankswitch::ExtensionMap Bankswitch::ourExtensions = {

src/emucore/Bankswitch.hxx

@@ -52,23 +52,23 @@ class Bankswitch
       NumMulti = _128IN1 - _2IN1 + 1,
     };
 
-#ifdef GUI_SUPPORT
     struct SizesType {
       size_t minSize{0};
       size_t maxSize{0};
     };
     static constexpr size_t any_KB = 0;
 
-    static const std::array<SizesType, static_cast<uInt32>(Type::NumSchemes)> Sizes;
+    static const std::array<SizesType,
-#endif
+                            static_cast<uInt32>(Type::NumSchemes)> Sizes;
 
     // Info about the various bankswitch schemes, useful for displaying
     // in GUI dropdown boxes, etc
     struct Description {
-      const char* const name{nullptr};
+      string_view name;
-      const char* const desc{nullptr};
+      string_view desc;
     };
-    static const std::array<Description, static_cast<int>(Type::NumSchemes)> BSList;
+    static const std::array<Description,
+                            static_cast<uInt32>(Type::NumSchemes)> BSList;
 
   public:
     // Convert BSType enum to string
@@ -90,14 +90,22 @@ class Bankswitch
       @param name  Filename of potential ROM file
       @param ext   The extension extracted from the given file
      */
-    static bool isValidRomName(const string& name, string& ext);
+    static bool isValidRomName(string_view name, string& ext);
 
     /**
       Convenience functions for different parameter types.
      */
-    static bool isValidRomName(const FSNode& name, string& ext);
+    static inline bool isValidRomName(const FSNode& name, string& ext) {
-    static bool isValidRomName(const FSNode& name);
+      return isValidRomName(name.getPath(), ext);
-    static bool isValidRomName(const string& name);
+    }
+    static inline bool isValidRomName(const FSNode& name) {
+      string ext;  // extension not used
+      return isValidRomName(name.getPath(), ext);
+    }
+    static inline bool isValidRomName(string_view name) {
+      string ext;  // extension not used
+      return isValidRomName(name, ext);
+    }
 
     // Output operator
     friend ostream& operator<<(ostream& os, const Bankswitch::Type& t) {
@@ -106,14 +114,16 @@ class Bankswitch
 
   private:
     struct TypeComparator {
-      bool operator() (const string& a, const string& b) const {
+      bool operator() (string_view a, string_view b) const {
         return BSPF::compareIgnoreCase(a, b) < 0;
       }
     };
-    using ExtensionMap = const std::map<string, Bankswitch::Type, TypeComparator>;
+    using ExtensionMap = const std::map<string_view, Bankswitch::Type,
+                                        TypeComparator>;
     static ExtensionMap ourExtensions;
 
-    using NameToTypeMap = const std::map<string, Bankswitch::Type, TypeComparator>;
+    using NameToTypeMap = const std::map<string_view, Bankswitch::Type,
+                                         TypeComparator>;
     static NameToTypeMap ourNameToTypes;
 
   private: