Optimize Schematic.Deserialize, a lot

Circuit/Schematic/Schematic.cs

@@ -42,10 +42,35 @@ public class Schematic
         /// </summary>
         public ILog Log { get { return log; } set { log = value; } }
 
-        public Schematic(ILog Log) : this() { log = Log; }
-        public Schematic()
+        public Schematic(ILog Log, IEnumerable<Element> Elements = null) : this(Elements) 
+        {
+            log = Log; 
+        }
+        public Schematic(IEnumerable<Element> Elements = null)
         {
             elements = new ElementCollection();
+            if (Elements != null)
+            {
+                // If we rely on the normal events for adding/removing these components,
+                // it's very slow because the nodes get rebuilt every time a new
+                // component is added. To avoid this, just manually connect everything
+                // here, and then rebuild the nodes once.
+                elements.AddRange(Elements);
+                foreach (Symbol i in elements.OfType<Symbol>())
+                    circuit.Components.Add(i.Component);
+                // Rebuild the nodes here so we at least reduce to one node per connected
+                // group of wires.
+                RebuildNodes(null, false);
+                foreach (Element i in elements)
+                    foreach (Terminal j in i.Terminals)
+                        j.ConnectTo(NodeAt(i.MapTerminal(j)));
+                // Rebuild the nodes again in case a named wire changed the name of the nodes.
+                RebuildNodes(null, true);
+            }
+
+            // We skipped this usual event setup for the initial elements, add the events now.
+            foreach (Element i in elements)
+                i.LayoutChanged += OnLayoutChanged;
             elements.ItemAdded += OnElementAdded;
             elements.ItemRemoved += OnElementRemoved;
         }
@@ -197,22 +222,26 @@ protected void OnLayoutChanged(object sender, EventArgs e)
             UpdateTerminals(of);
         }
 
-        // Wires was a single node but it is now two. Break it into two sets of nodes
-        // and return the one containing Target.
-        private IEnumerable<Wire> ConnectedTo(IEnumerable<Wire> Wires, Wire Target)
+        private IEnumerable<Wire> ConnectedTo(IEnumerable<Wire> Wires, Wire Target, HashSet<Wire> visited)
         {
-            // Repeatedly search for connections with the target.
-            IEnumerable<Wire> connected = new Wire[] { Target };
-            int count = connected.Count();
-            while (true)
+            foreach (Wire i in Wires.Where(j => !visited.Contains(j)))
             {
-                connected = Wires.Where(i => connected.Any(j => i.IsConnectedTo(j))).ToArray();
-                if (connected.Count() == count)
-                    break;
-                count = connected.Count();
+                if (i.IsConnectedTo(Target))
+                {
+                    visited.Add(i);
+                    yield return i;
+                    foreach (Wire j in ConnectedTo(Wires, i, visited))
+                        yield return j;
+                }
             }
+        }
 
-            return connected;
+        // Wires was a single node but it is now two. Break it into two sets of nodes
+        // and return the one containing Target.
+        private IEnumerable<Wire> ConnectedTo(IEnumerable<Wire> Wires, Wire Target)
+        {
+            HashSet<Wire> visited = new HashSet<Wire>();
+            return ConnectedTo(Wires.Buffer(), Target, visited);
         }
 
         // Merge all of the nodes contained in wires to one.
@@ -244,7 +273,7 @@ private Node MergeNode(IEnumerable<Wire> Wires)
                 circuit.Nodes.Add(n);
             }
 
-            foreach (Wire i in Wires)
+            foreach (Wire i in Wires.Where(j => j.Node != n))
             {
                 i.Node = n;
                 UpdateTerminals(i);
@@ -289,16 +318,17 @@ private void UpdateTerminals(Element Of)
         {
             foreach (Terminal i in Of.Terminals)
                 Connect(i, NodeAt(Of.MapTerminal(i), Of as Wire));
-
-            // If Of is a named wire, the nodes might have changed.
-            if (Of is Symbol symbol && symbol.Component is NamedWire wire)
-                RebuildNodes(wire.ConnectedTo, false);
         }
 
         private void Connect(Terminal T, Node V)
         {
             if (V != T.ConnectedTo)
+            {
                 T.ConnectTo(V);
+                // If this terminal is a named wire, the nodes need to be rebuilt.
+                if (T.Owner is NamedWire)
+                    RebuildNodes(V, false);
+            }
         }
 
         private void LogComponents()
@@ -341,8 +371,8 @@ public XElement Serialize()
 
         public static Schematic Deserialize(XElement X, ILog Log)
         {
-            Schematic s = new Schematic(Log);
-            s.Elements.AddRange(X.Elements("Element").Select(i => Element.Deserialize(i)));
+            IEnumerable<Element> elements = X.Elements("Element").Select(i => Element.Deserialize(i));
+            Schematic s = new Schematic(Log, elements);
             s.Circuit.Name = Value(X.Attribute("Name"));
             s.Circuit.Description = Value(X.Attribute("Description"));
             s.Circuit.PartNumber = Value(X.Attribute("PartNumber"));