Bring back search performance improvement (#15789)

src/DynamoCore/Engine/EngineController.cs

@@ -174,6 +174,7 @@ public void Dispose()
 
             liveRunnerServices.Dispose();
             codeCompletionServices = null;
+            CompilationServices = null;
         }
 
         /// <summary>

src/DynamoCore/Models/DynamoModel.cs

@@ -454,6 +454,10 @@ public void ShutDown(bool shutdownHost)
 
             AnalyticsService.ShutDown();
 
+            LuceneSearch.LuceneUtilityNodeSearch = null;
+            LuceneSearch.LuceneUtilityNodeAutocomplete = null;
+            LuceneSearch.LuceneUtilityPackageManager = null;
+
             State = DynamoModelState.NotStarted;
             OnShutdownCompleted(); // Notify possible event handlers.
         }

src/DynamoCoreWpf/DynamoCoreWpf.csproj

@@ -432,6 +432,7 @@
     <Compile Include="ViewModels\Preview\ConnectorAnchorViewModel.cs" />
     <Compile Include="ViewModels\Preview\ConnectorContextMenuViewModel.cs" />
     <Compile Include="ViewModels\RunSettingsViewModel.cs" />
+    <Compile Include="Utilities\ActionDebouncer.cs" />
     <Compile Include="ViewModels\Search\BrowserInternalElementViewModel.cs" />
     <Compile Include="ViewModels\Search\BrowserItemViewModel.cs" />
     <Compile Include="ViewModels\Search\NodeAutoCompleteSearchViewModel.cs" />

src/DynamoCoreWpf/UI/SharedResourceDictionary.cs

@@ -67,7 +67,6 @@ public static class SharedDictionaryManager
         private static ResourceDictionary outPortsDictionary;
         private static ResourceDictionary inPortsDictionary;
         private static ResourceDictionary _liveChartDictionary;
-
 
         public static string ThemesDirectory 
         {

src/DynamoCoreWpf/Utilities/ActionDebouncer.cs

@@ -0,0 +1,61 @@
+using Dynamo.Logging;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Dynamo.Wpf.Utilities
+{
+    /// <summary>
+    /// The ActionDebouncer class offers a means to reduce the number of UI notifications for a specified time.
+    /// It is meant to be used in UI elements where too many UI updates can cause perfomance issues.
+    /// </summary>
+    internal class ActionDebouncer(ILogger logger) : IDisposable
+    {
+        private readonly ILogger logger = logger;
+        private CancellationTokenSource cts;
+
+        public void Cancel()
+        {
+            if (cts != null)
+            {
+                cts.Cancel();
+                cts.Dispose();
+                cts = null;
+            }
+        }
+
+        /// <summary>
+        /// Delays the "action" for a "timeout" number of milliseconds
+        /// The input Action will run on same syncronization context as the Debounce method call.
+        /// </summary>
+        /// <param name="timeout">Number of milliseconds to wait</param>
+        /// <param name="action">The action to execute after the timeout runs out.</param>
+        /// <returns>A task that finishes when the deboucing is cancelled or the input action has completed (successfully or not). Should be discarded in most scenarios.</returns>
+        public void Debounce(int timeout, Action action)
+        {
+            Cancel();
+            cts = new CancellationTokenSource();
+
+            Task.Delay(timeout, cts.Token).ContinueWith((t) =>
+            {
+                try
+                {
+                    if (t.Status == TaskStatus.RanToCompletion)
+                    {
+                        action();
+                    }
+                }
+                catch (Exception ex)
+                {
+                    logger?.Log("Failed to run debounce action with the following error:");
+                    logger?.Log(ex.ToString());
+                }
+            }, TaskScheduler.FromCurrentSynchronizationContext());
+        }
+
+        public void Dispose()
+        {
+            Cancel();
+        }
+    }
+}

src/DynamoCoreWpf/ViewModels/Core/WorkspaceViewModel.cs

@@ -606,11 +606,6 @@ public WorkspaceViewModel(WorkspaceModel model, DynamoViewModel dynamoViewModel)
             foreach (NoteModel note in Model.Notes) Model_NoteAdded(note);
             foreach (AnnotationModel annotation in Model.Annotations) Model_AnnotationAdded(annotation);
             foreach (ConnectorModel connector in Model.Connectors) Connectors_ConnectorAdded(connector);
-
-            NodeAutoCompleteSearchViewModel = new NodeAutoCompleteSearchViewModel(DynamoViewModel)
-            {
-                Visible = true
-            };
 
             geoScalingViewModel = new GeometryScalingViewModel(this.DynamoViewModel);
             geoScalingViewModel.ScaleValue = Convert.ToInt32(Math.Log10(Model.ScaleFactor));

src/DynamoCoreWpf/ViewModels/Search/SearchViewModel.cs

@@ -18,7 +18,9 @@
 using Dynamo.UI;
 using Dynamo.Utilities;
 using Dynamo.Wpf.Services;
+using Dynamo.Wpf.Utilities;
 using Dynamo.Wpf.ViewModels;
+using DynamoUtilities;
 
 namespace Dynamo.ViewModels
 {
@@ -73,7 +75,11 @@ public bool BrowserVisibility
             set { browserVisibility = value; RaisePropertyChanged("BrowserVisibility"); }
         }
 
-        private string searchText;
+        internal int searchDelayTimeout = 150;
+        // Feature flags activated debouncer for the search UI.
+        internal ActionDebouncer searchDebouncer = null;
+
+        private string searchText = string.Empty;
         /// <summary>
         ///     SearchText property
         /// </summary>
@@ -86,10 +92,28 @@ public string SearchText
             set
             {
                 searchText = value;
-                OnSearchTextChanged(this, EventArgs.Empty);
+
                 RaisePropertyChanged("SearchText");
                 RaisePropertyChanged("BrowserRootCategories");
                 RaisePropertyChanged("CurrentMode");
+
+                // The searchText is set multiple times before the control becomes visible and interactable.
+                // To prevent any debounces from triggering at some unexpected point before or after the control
+                // becomes visible, this flag is only set once the searchText value is set by the user
+                // (unless it somehow gets set somewhere else)
+                //
+                // pinzart: The search text is set multiple times with an empty value. Seems sufficient to only use the debouncer
+                // if we get a non-empty value.
+                if (!string.IsNullOrEmpty(searchText) && searchDebouncer != null)
+                {
+                    searchDebouncer.Debounce(searchDelayTimeout, () => OnSearchTextChanged(this, EventArgs.Empty));
+                }
+                else
+                {
+                    // Make sure any previously scheduled debounces are cancelled
+                    searchDebouncer?.Cancel();
+                    OnSearchTextChanged(this, EventArgs.Empty);
+                }
             }
         }
 
@@ -374,9 +398,19 @@ internal SearchViewModel(DynamoViewModel dynamoViewModel)
 
             iconServices = new IconServices(pathManager);
 
+            DynamoFeatureFlagsManager.FlagsRetrieved += TryInitializeDebouncer;
+
             InitializeCore();
         }
 
+        private void TryInitializeDebouncer()
+        {
+            if (DynamoModel.FeatureFlags?.CheckFeatureFlag("searchbar_debounce", false) ?? false)
+            {
+                searchDebouncer ??= new ActionDebouncer(dynamoViewModel?.Model?.Logger);
+            }
+        }
+
         // Just for tests. Please refer to LibraryTests.cs
         internal SearchViewModel(NodeSearchModel model)
         {
@@ -407,6 +441,9 @@ public override void Dispose()
             Model.EntryUpdated -= UpdateEntry;
             Model.EntryRemoved -= RemoveEntry;
 
+            searchDebouncer?.Dispose();
+            DynamoFeatureFlagsManager.FlagsRetrieved -= TryInitializeDebouncer;
+
             base.Dispose();
         }
 
@@ -434,6 +471,9 @@ private void InitializeCore()
 
             DefineFullCategoryNames(LibraryRootCategories, "");
             InsertClassesIntoTree(LibraryRootCategories);
+
+            // If feature flags are already cached, try to initialize the debouncer
+            TryInitializeDebouncer();
         }
 
         private void AddEntry(NodeSearchElement entry)

src/DynamoCoreWpf/Views/Core/DynamoView.xaml.cs

@@ -2081,6 +2081,7 @@ private void WindowClosed(object sender, EventArgs e)
             this.dynamoViewModel.RequestEnableShortcutBarItems -= DynamoViewModel_RequestEnableShortcutBarItems;
             this.dynamoViewModel.RequestExportWorkSpaceAsImage -= OnRequestExportWorkSpaceAsImage;
             this.dynamoViewModel.RequestShorcutToolbarLoaded -= onRequestShorcutToolbarLoaded;
+            PythonEngineManager.Instance.AvailableEngines.CollectionChanged -= OnPythonEngineListUpdated;
 
             if (homePage != null)
             {

src/Tools/DynamoFeatureFlags/FeatureFlagsClient.cs

@@ -85,7 +85,9 @@ internal FeatureFlagsClient(string userkey, string mobileKey = null, bool testMo
                 AllFlags = LdValue.ObjectFrom(new Dictionary<string,LdValue> { { "TestFlag1",LdValue.Of(true) },
                     { "TestFlag2", LdValue.Of("I am a string") },
                     //in tests we want instancing on so we can test it.
-                    { "graphics-primitive-instancing", LdValue.Of(true) } });
+                    { "graphics-primitive-instancing", LdValue.Of(true) },
+                    //in tests we want search debouncing on so we can test it.
+                    { "searchbar_debounce", LdValue.Of(true) } });
                 return;
             }