WorkspaceViewModel fast node and connector lookup

src/DynamoCoreWpf/ViewModels/Core/AnnotationViewModel.cs

@@ -959,10 +959,7 @@ private void CollapseConnectors()
 
             foreach (var connector in connectorsToHide)
             {
-                var connectorViewModel = WorkspaceViewModel
-                    .Connectors
-                    .Where(x => connector.GUID == x.ConnectorModel.GUID)
-                    .FirstOrDefault();
+                var connectorViewModel = WorkspaceViewModel.FindConnector(connector.GUID);
 
                 connectorViewModel.IsCollapsed = true;
             }
@@ -977,10 +974,7 @@ private void RedrawConnectors()
 
             foreach (var connector in allNodes.SelectMany(x => x.AllConnectors))
             {
-                var connectorViewModel = WorkspaceViewModel
-                    .Connectors
-                    .Where(x => connector.GUID == x.ConnectorModel.GUID)
-                    .FirstOrDefault();
+                var connectorViewModel = WorkspaceViewModel.FindConnector(connector.GUID);
 
                 connectorViewModel.Redraw();
                 connector.Start.Owner.ReportPosition();
@@ -1031,14 +1025,11 @@ private void UpdateConnectorsAndPortsOnShowContents(IEnumerable<ModelBase> nodes
         {
             foreach (var nodeModel in nodes.OfType<NodeModel>())
             {
-                var connectorGuids = nodeModel.AllConnectors
-                    .Select(x => x.GUID);
+                var connectorViewModels = nodeModel.AllConnectors
+                    .Select(x => WorkspaceViewModel.FindConnector(x.GUID))
+                    .Where(c => c != null);
 
-                var connectorViewModels = WorkspaceViewModel.Connectors
-                    .Where(x => connectorGuids.Contains(x.ConnectorModel.GUID))
-                    .ToList();
-
-                connectorViewModels.ForEach(x => x.IsCollapsed = false);
+                foreach(var c in connectorViewModels) c.IsCollapsed = false;
 
                 // Set IsProxyPort back to false when the group is expanded.
                 nodeModel.InPorts.ToList().ForEach(x => x.IsProxyPort = false);

src/DynamoCoreWpf/ViewModels/Core/ConnectorViewModel.cs

@@ -483,15 +483,15 @@ public NodeViewModel Nodevm
         {
             get
             {
-                return workspaceViewModel.Nodes?.FirstOrDefault(x => x.NodeLogic.GUID == model.Start.Owner.GUID);
+                return workspaceViewModel.FindNode(model.Start.Owner.GUID);
             }
         }
 
         public NodeViewModel NodeEnd
         {
             get
             {
-                return workspaceViewModel.Nodes?.FirstOrDefault(x => x.NodeLogic.GUID == model.End.Owner.GUID);
+                return workspaceViewModel.FindNode(model.End.Owner.GUID);
             }
         }
 

src/DynamoCoreWpf/ViewModels/Core/HomeWorkspaceViewModel.cs

@@ -232,8 +232,7 @@ private void UpdateNodesDeltaState(List<Guid> nodeGuids, bool graphExecuted)
 
             foreach (Guid t in nodeGuids)
             {
-                var nodeViewModel = Nodes.FirstOrDefault(x => x.NodeModel.GUID == t);
-                if (nodeViewModel != null)
+                if (FindNode(t) is NodeViewModel nodeViewModel)
                 {
                     nodeViewModel.ShowExecutionPreview = nodeViewModel.DynamoViewModel.ShowRunPreview;
                     nodeViewModel.IsNodeAddedRecently = false;
@@ -358,7 +357,7 @@ private void UpdateNodeInfoBubbleContent(EvaluationCompletedEventArgs evalargs)
 
             foreach (var messageID in evalargs.MessageKeys)
             {
-                var node = Nodes.FirstOrDefault(n => n.Id == messageID);
+                var node = FindNode(messageID);
                 if (node == null) continue;
 
                 node.UpdateBubbleContent();

src/DynamoCoreWpf/ViewModels/Core/NodeViewModel.cs

@@ -1970,7 +1970,7 @@ private void RaisePropertyChangedOnDownStreamNodes()
 
             foreach (var inode in nodes)
             {
-                var current = this.WorkspaceViewModel.Nodes.FirstOrDefault(x => x.NodeLogic == inode);
+                var current = WorkspaceViewModel.FindNode(inode.GUID);
                 if (current != null)
                 {
                     current.RaisePropertyChanged("IsFrozen");

src/DynamoCoreWpf/ViewModels/Core/NoteViewModel.cs

@@ -136,9 +136,7 @@ public NodeViewModel PinnedNode
                     return null;
                 }
 
-                return WorkspaceViewModel.Nodes
-                    .Where(x => x.Id == Model.PinnedNode.GUID)
-                    .FirstOrDefault();
+                return WorkspaceViewModel.FindNode(Model.PinnedNode.GUID);
             }
         }
 

src/DynamoCoreWpf/ViewModels/Core/OutPortViewModel.cs

@@ -302,9 +302,9 @@ private void BreakConnections(object parameter)
             Analytics.TrackEvent(Actions.Break, Categories.ConnectorOperations, port.PortType.ToString(), port.Connectors.Count);
             for (var i = port.Connectors.Count - 1; i >= 0; i--)
             {
+                var portConnectorGuid = port.Connectors[i].GUID;
                 // Attempting to get the relevant ConnectorViewModel via matching GUID
-                ConnectorViewModel connectorViewModel = node.WorkspaceViewModel.Connectors
-                    .FirstOrDefault(x => x.ConnectorModel.GUID == port.Connectors[i].GUID);
+                ConnectorViewModel connectorViewModel = node.WorkspaceViewModel.FindConnector(portConnectorGuid);
 
                 if (connectorViewModel == null)
                 {
@@ -325,8 +325,7 @@ private void HideConnections(object parameter)
             foreach(var connector in port.Connectors)
             {
                 // Attempting to get the relevant ConnectorViewModel via matching GUID
-                var connectorViewModel = node.WorkspaceViewModel.Connectors
-                    .FirstOrDefault(x => x.ConnectorModel.GUID == connector.GUID);
+                var connectorViewModel = node.WorkspaceViewModel.FindConnector(connector.GUID);
                 connectorViewModel?.ShowhideConnectorCommand.Execute(!AreConnectorsHidden);
             }
             if (AreConnectorsHidden)

src/DynamoCoreWpf/ViewModels/Core/WorkspaceViewModel.cs

@@ -285,11 +285,17 @@ public bool IsCursorForced
 
         [JsonIgnore]
         public CompositeCollection WorkspaceElements { get; } = new CompositeCollection();
+
         [JsonIgnore]
         public ObservableCollection<ConnectorViewModel> Connectors { get; } = new ObservableCollection<ConnectorViewModel>();
 
+        private Dictionary<Guid, ConnectorViewModel> connectorDict = new();
+
         [JsonProperty("NodeViews")]
         public ObservableCollection<NodeViewModel> Nodes { get; } = new ObservableCollection<NodeViewModel>();
+
+        private Dictionary<Guid, NodeViewModel> nodeDict = new();
+
         // Do not serialize notes, they will be converted to annotations during serialization
         [JsonIgnore]
         public ObservableCollection<NoteViewModel> Notes { get; } = new ObservableCollection<NoteViewModel>();
@@ -713,9 +719,11 @@ public override void Dispose()
             Connectors.ToList().ForEach(connectorViewmModel => connectorViewmModel.Dispose());
             Annotations.ToList().ForEach(AnnotationViewModel => AnnotationViewModel.Dispose());
             Nodes.Clear();
+            nodeDict.Clear();
             Notes.Clear();
             Pins.Clear();
             Connectors.Clear();
+            connectorDict.Clear();
             Errors.Clear();
             Annotations.Clear();
             InCanvasSearchViewModel?.Dispose();
@@ -860,15 +868,18 @@ void CopyPasteChanged(object sender, EventArgs e)
 
         void Connectors_ConnectorAdded(ConnectorModel c)
         {
-            var viewModel = new ConnectorViewModel(this, c);
-            if (Connectors.All(x => x.ConnectorModel != c))
+            if (!connectorDict.ContainsKey(c.GUID))
+            {
+                // Only create the view model if needed. This prevents event handler leaks
+                var viewModel = new ConnectorViewModel(this, c);
+                connectorDict[c.GUID] = viewModel;
                 Connectors.Add(viewModel);
+            }
         }
 
         void Connectors_ConnectorDeleted(ConnectorModel c)
         {
-            var connector = Connectors.FirstOrDefault(x => x.ConnectorModel == c);
-            if (connector != null)
+            if (connectorDict.Remove(c.GUID, out var connector))
             {
                 Connectors.Remove(connector);
                 connector.Dispose();
@@ -930,6 +941,7 @@ void Model_NodesCleared()
                     nodeViewModel.Dispose();
                 }
                 Nodes.Clear();
+                nodeDict.Clear();
             }
             Errors.Clear();
 
@@ -948,7 +960,7 @@ void Model_NodeRemoved(NodeModel node)
             NodeViewModel nodeViewModel;
             lock (Nodes)
             {
-                nodeViewModel = Nodes.First(x => x.NodeLogic == node);
+                nodeDict.Remove(node.GUID, out nodeViewModel);
                 if (nodeViewModel.ErrorBubble != null)
                     Errors.Remove(nodeViewModel.ErrorBubble);
                 Nodes.Remove(nodeViewModel);
@@ -970,6 +982,7 @@ void Model_NodeAdded(NodeModel node)
             lock (Nodes)
             {
                 Nodes.Add(nodeViewModel);
+                nodeDict[node.GUID] = nodeViewModel;
             }
             if (nodeViewModel.ErrorBubble != null)
                 Errors.Add(nodeViewModel.ErrorBubble);
@@ -979,6 +992,20 @@ void Model_NodeAdded(NodeModel node)
             SetStopNodeZoomAnimationBehavior(zoomAnimationThresholdFeatureFlagVal);
         }
 
+        internal NodeViewModel? FindNode(Guid nodeGuid)
+        {
+            return nodeDict.TryGetValue(nodeGuid, out var nodeModel)
+                ? nodeModel
+                : null;
+        }
+
+        internal ConnectorViewModel? FindConnector(Guid connectorGuid)
+        {
+            return connectorDict.TryGetValue(connectorGuid, out var connectorModel)
+                ? connectorModel
+                : null;
+        }
+
         void PostNodeChangeActions()
         {
             if (RunSettingsViewModel == null) return;
@@ -1896,10 +1923,10 @@ private void RefreshViewOnSelectionChange(object sender, NotifyCollectionChanged
         /// <returns>Found <see cref="ViewModelBase"/> object.</returns>
         internal ViewModelBase GetViewModelInternal(Guid modelGuid)
         {
-            ViewModelBase foundModel = (Connectors.FirstOrDefault(c => c.ConnectorModel.GUID == modelGuid)
-                ?? Nodes.FirstOrDefault(node => node.NodeModel.GUID == modelGuid) as ViewModelBase)
-                ?? (Notes.FirstOrDefault(note => note.Model.GUID == modelGuid)
-                ?? Annotations.FirstOrDefault(annotation => annotation.AnnotationModel.GUID == modelGuid) as ViewModelBase);
+            ViewModelBase foundModel = FindConnector(modelGuid) as ViewModelBase
+                ?? FindNode(modelGuid) as ViewModelBase
+                ?? Notes.FirstOrDefault(note => note.Model.GUID == modelGuid) as ViewModelBase
+                ?? Annotations.FirstOrDefault(annotation => annotation.AnnotationModel.GUID == modelGuid) as ViewModelBase;
 
             return foundModel;
         }