Connectivity optimizations

Don't copy the recursion test cache when copy-constructing
SCH_SHEET_PATHs as it's not needed in connectivity

Fix a few places that were copying unnecessarily

eeschema/connection_graph.cpp

@@ -424,7 +424,7 @@ void CONNECTION_GRAPH::Recalculate( const SCH_SHEET_LIST& aSheetList, bool aUnco
 }
 
 
-void CONNECTION_GRAPH::updateItemConnectivity( SCH_SHEET_PATH aSheet,
+void CONNECTION_GRAPH::updateItemConnectivity( const SCH_SHEET_PATH& aSheet,
                                                const std::vector<SCH_ITEM*>& aItemList )
 {
     std::unordered_map< wxPoint, std::vector<SCH_ITEM*> > connection_map;
@@ -1807,8 +1807,8 @@ void CONNECTION_GRAPH::propagateToNeighbors( CONNECTION_SUBGRAPH* aSubgraph )
 }
 
 
-std::shared_ptr<SCH_CONNECTION> CONNECTION_GRAPH::getDefaultConnection( SCH_ITEM* aItem,
+std::shared_ptr<SCH_CONNECTION>
-                                                                        SCH_SHEET_PATH aSheet )
+CONNECTION_GRAPH::getDefaultConnection( SCH_ITEM* aItem, const SCH_SHEET_PATH& aSheet )
 {
     auto c = std::shared_ptr<SCH_CONNECTION>( nullptr );
 

eeschema/connection_graph.h

@@ -366,7 +366,7 @@ private:
      * @param aSheet is the path to the sheet of all items in the list
      * @param aItemList is a list of items to consider
      */
-    void updateItemConnectivity( SCH_SHEET_PATH aSheet,
+    void updateItemConnectivity( const SCH_SHEET_PATH& aSheet,
                                  const std::vector<SCH_ITEM*>& aItemList );
 
     /**
@@ -425,7 +425,8 @@ private:
      * @param aItem is an item that can generate a connection name
      * @return a connection generated from the item, or nullptr if item is not valid
      */
-    std::shared_ptr<SCH_CONNECTION> getDefaultConnection( SCH_ITEM* aItem, SCH_SHEET_PATH aSheet );
+    std::shared_ptr<SCH_CONNECTION> getDefaultConnection( SCH_ITEM* aItem,
+                                                          const SCH_SHEET_PATH& aSheet );
 
     void recacheSubgraphName( CONNECTION_SUBGRAPH* aSubgraph, const wxString& aOldName );
 

eeschema/sch_sheet_path.cpp

@@ -103,6 +103,30 @@ SCH_SHEET_PATH::SCH_SHEET_PATH()
 }
 
 
+SCH_SHEET_PATH::SCH_SHEET_PATH( const SCH_SHEET_PATH& aOther )
+{
+    initFromOther( aOther );
+}
+
+
+SCH_SHEET_PATH& SCH_SHEET_PATH::operator=( const SCH_SHEET_PATH& aOther )
+{
+    initFromOther( aOther );
+    return *this;
+}
+
+
+void SCH_SHEET_PATH::initFromOther( const SCH_SHEET_PATH& aOther )
+{
+    m_sheets       = aOther.m_sheets;
+    m_pageNumber   = aOther.m_pageNumber;
+    m_current_hash = aOther.m_current_hash;
+
+    // Note: don't copy m_recursion_test_cache as it is slow and we want SCH_SHEET_PATHS to be
+    // very fast to construct for use in the connectivity algorithm.
+}
+
+
 void SCH_SHEET_PATH::Rehash()
 {
     m_current_hash = 0;

eeschema/sch_sheet_path.h

@@ -132,6 +132,10 @@ protected:
 public:
     SCH_SHEET_PATH();
 
+    SCH_SHEET_PATH( const SCH_SHEET_PATH& aOther );
+
+    SCH_SHEET_PATH& operator=( const SCH_SHEET_PATH& aOther );
+
     /// Forwarded method from std::vector
     SCH_SHEET* at( size_t aIndex ) const { return m_sheets.at( aIndex ); }
 
@@ -304,6 +308,9 @@ public:
 
     bool operator<( const SCH_SHEET_PATH& d1 ) const { return m_sheets < d1.m_sheets; }
 
+private:
+
+    void initFromOther( const SCH_SHEET_PATH& aOther );
 };