Cache sheet path to string conversion in UpdateSymbolInstances

Profiling of large designs (with many hierarchical sheets)
showed that this can be a huge (4x) speed up to schematic
loading times.

eeschema/files-io.cpp

@@ -43,6 +43,7 @@
 #include <sch_component.h>
 #include <schematic.h>
 #include <wildcards_and_files_ext.h>
+#include <profile.h>
 #include <project_rescue.h>
 #include <reporter.h>
 #include <eeschema_config.h>
@@ -244,6 +245,8 @@ bool SCH_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
     if( !AskToSaveChanges() )
         return false;
 
+    PROF_COUNTER openFiles( "OpenProjectFile" );
+
     wxFileName pro = fullFileName;
     pro.SetExt( ProjectFileExtension );
 
@@ -517,6 +520,10 @@ bool SCH_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
         m_infoBar->ShowMessage( "Schematic file is read only.", wxICON_WARNING );
     }
 
+#ifdef PROFILE
+    openFiles.Show();
+#endif
+
     return true;
 }
 

eeschema/sch_sheet_path.cpp

@@ -773,6 +773,20 @@ void SCH_SHEET_LIST::UpdateSymbolInstances(
 
     GetComponents( symbolInstances, true, true );
 
+    std::map<KIID_PATH, wxString> pathNameCache;
+
+    // Calculating the name of a path is somewhat expensive; on large designs with many components
+    // this can blow up to a serious amount of time when loading the schematic
+    auto getName =
+            [&pathNameCache]( const KIID_PATH& aPath ) -> const wxString&
+            {
+                if( pathNameCache.count( aPath ) )
+                    return pathNameCache.at( aPath );
+
+                pathNameCache[aPath] = aPath.AsString();
+                return pathNameCache[aPath];
+            };
+
     for( size_t i = 0; i < symbolInstances.GetCount(); i++ )
     {
         // The instance paths are stored in the file sans root path so the comparison
@@ -780,9 +794,9 @@ void SCH_SHEET_LIST::UpdateSymbolInstances(
         wxString path = symbolInstances[i].GetPath();
 
         auto it = std::find_if( aSymbolInstances.begin(), aSymbolInstances.end(),
-                    [ path ]( const COMPONENT_INSTANCE_REFERENCE& r ) -> bool
+                    [ path, &getName ]( const COMPONENT_INSTANCE_REFERENCE& r ) -> bool
                     {
-                        return path == r.m_Path.AsString();
+                        return path == getName( r.m_Path );
                     }
                 );