Improve notebook explorer performance

Cache relative paths of items, as `IOneNoteItem.GetRelativePath` builds a string everytime.
Cache the OneNote hierarchy, only query once while traversing.

Author: Odotocodot

Changelog.md

@@ -6,6 +6,7 @@
 - Update to Net 9.0
 - Refactored code
 - Migrate from `Odotocodot.OneNote.Linq 1.2.0` to `LinqToOneNote 2.0.0`
+- Improve notebook explorer performance.
 
 
 ## 2.1.2 - 2025-6-11

Flow.Launcher.Plugin.OneNote/Main.cs

@@ -9,7 +9,7 @@
 using OneNoteApp = LinqToOneNote.OneNote;
 namespace Flow.Launcher.Plugin.OneNote
 {
-    #nullable disable
+#nullable disable
     public class Main : IAsyncPlugin, IContextMenu, ISettingProvider, IDisposable
     {
         private PluginInitContext context;
@@ -18,6 +18,7 @@ public class Main : IAsyncPlugin, IContextMenu, ISettingProvider, IDisposable
         private SearchManager searchManager;
         private Settings settings;
         private IconProvider iconProvider;
+        private VisibilityChanged visibilityChanged;
 
         private static SemaphoreSlim semaphore;
 
@@ -26,21 +27,19 @@ public Task InitAsync(PluginInitContext context)
         {
             this.context = context;
             settings = context.API.LoadSettingJsonStorage<Settings>();
-            
+
+            visibilityChanged = new VisibilityChanged(context);
             iconProvider = new IconProvider(context, settings);
             resultCreator = new ResultCreator(context, settings, iconProvider);
-            searchManager = new SearchManager(context, settings, resultCreator);
-            semaphore = new SemaphoreSlim(1,1);
-            context.API.VisibilityChanged += OnVisibilityChanged;
-            return Task.CompletedTask;
-        }
+            searchManager = new SearchManager(context, settings, resultCreator, visibilityChanged);
+            semaphore = new SemaphoreSlim(1, 1);
 
-        private void OnVisibilityChanged(object _, VisibilityChangedEventArgs e)
-        {
-            if (context.CurrentPluginMetadata.Disabled || !e.IsVisible)
+            visibilityChanged.Subscribe(static (isVisible) =>
             {
-                Task.Run(OneNoteApp.ReleaseComObject);
-            }
+                if (!isVisible)
+                    Task.Run(OneNoteApp.ReleaseComObject);
+            });
+            return Task.CompletedTask;
         }
 
         private static async Task OneNoteInitAsync(CancellationToken token)
@@ -70,7 +69,7 @@ public async Task<List<Result>> QueryAsync(Query query, CancellationToken token)
 
             await init;
 
-            return searchManager.Query(query.Search);
+            return searchManager.Query(query);
         }
 
         public List<Result> LoadContextMenus(Result selectedResult)
@@ -85,7 +84,7 @@ public Control CreateSettingPanel()
 
         public void Dispose()
         {
-            context.API.VisibilityChanged -= OnVisibilityChanged;
+            visibilityChanged.Dispose();
             semaphore.Dispose();
             OneNoteApp.ReleaseComObject();
         }

Flow.Launcher.Plugin.OneNote/ResultCreator.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
@@ -16,6 +17,7 @@ public class ResultCreator
         private readonly PluginInitContext context;
         private readonly Settings settings;
         private readonly IconProvider iconProvider;
+        private readonly ConcurrentDictionary<RelativePathKey, string> relativePaths = [];
 
         private const string PathSeparator = " > ";
         private const string BulletPoint = "\u2022  ";
@@ -28,7 +30,9 @@ public ResultCreator(PluginInitContext context, Settings settings, IconProvider
             this.context = context;
         }
 
-        private static string GetNicePath(IOneNoteItem item, string separator = PathSeparator) => item.GetRelativePath(false, separator);
+        private readonly record struct RelativePathKey(IOneNoteItem Item, string Separator);
+        private string GetNicePath(IOneNoteItem item, string separator = PathSeparator) 
+            => relativePaths.GetOrAdd(new RelativePathKey(item, separator), v => v.Item.GetRelativePath(false, v.Separator));
 
         private string GetTitle(IOneNoteItem item, List<int>? highlightData)
         {

Flow.Launcher.Plugin.OneNote/Search/NotebookExplorer.cs

@@ -11,13 +11,22 @@ namespace Flow.Launcher.Plugin.OneNote.Search
 	public class NotebookExplorer : SearchBase
 	{
 		private readonly TitleSearch titleSearch;
-		public NotebookExplorer(PluginInitContext context, Settings settings, ResultCreator resultCreator, TitleSearch titleSearch) 
+		private Root? cache;
+		private bool updateCache;
+		public NotebookExplorer(PluginInitContext context, Settings settings, ResultCreator resultCreator, TitleSearch titleSearch, VisibilityChanged visibilityChanged)
 			: base(context, settings, resultCreator, settings.Keywords.NotebookExplorer)
 		{
 			this.titleSearch = titleSearch;
+			visibilityChanged.Subscribe(isVisible =>
+			{
+				if (!isVisible)
+				{
+					updateCache = true;
+				}
+			});
 		}
 
-		public override List<Result> GetResults(string query)
+		internal List<Result> GetResults(Query query)
 		{
 			if (!ValidateSearch(query, out string? search, out IOneNoteItem? parent, out IEnumerable<IOneNoteItem> collection))
 				return resultCreator.InvalidQuery(false);
@@ -40,13 +49,21 @@ public override List<Result> GetResults(string query)
 			return results;
 		}
 
-		private bool ValidateSearch(string query, out string? lastSearch, out IOneNoteItem? parent, out IEnumerable<IOneNoteItem> collection)
+		public override List<Result> GetResults(string query) => GetResults(query);
+
+		private bool ValidateSearch(Query query, out string? lastSearch, out IOneNoteItem? parent, out IEnumerable<IOneNoteItem> collection)
 		{
 			lastSearch = null;
 			parent = null;
-			collection = OneNoteApp.GetFullHierarchy().Notebooks;
-			
-			string search = query[(query.IndexOf(Keywords.NotebookExplorer, StringComparison.Ordinal) + Keywords.NotebookExplorer.Length)..];
+			if (updateCache || query.IsReQuery || cache == null)
+			{
+				cache = OneNoteApp.GetFullHierarchy();
+				updateCache = false;
+			}
+
+			collection = cache.Notebooks;
+
+			string search = query.Search[(query.Search.IndexOf(Keywords.NotebookExplorer, StringComparison.Ordinal) + Keywords.NotebookExplorer.Length)..];
 			const string separator = Keywords.NotebookExplorerSeparator;
 			var currIndex = search.IndexOf(separator, StringComparison.Ordinal);
 			var prevIndex = 0;

Flow.Launcher.Plugin.OneNote/Search/SearchManager.cs

@@ -9,20 +9,21 @@ public class SearchManager
 		private readonly DefaultSearch defaultSearch;
 		private readonly RecentPages recentPages;
 
-		public SearchManager(PluginInitContext context, Settings settings, ResultCreator resultCreator)
+		public SearchManager(PluginInitContext context, Settings settings, ResultCreator resultCreator, VisibilityChanged visibilityChanged)
 		{
 			titleSearch = new TitleSearch(context, settings, resultCreator);
-			notebookExplorer = new NotebookExplorer(context, settings, resultCreator, titleSearch);
+			notebookExplorer = new NotebookExplorer(context, settings, resultCreator, titleSearch, visibilityChanged);
 			recentPages = new RecentPages(context, settings, resultCreator);
 			defaultSearch = new DefaultSearch(context, settings, resultCreator);
 		}
-		
-		public List<Result> Query(string search)
+
+		public List<Result> Query(Query query)
 		{
+			string search = query.Search;
 			return search switch
 			{
 				{ } when search.StartsWithOrd(titleSearch.keyword) => titleSearch.GetResults(search),
-				{ } when search.StartsWithOrd(notebookExplorer.keyword) => notebookExplorer.GetResults(search),
+				{ } when search.StartsWithOrd(notebookExplorer.keyword) => notebookExplorer.GetResults(query),
 				{ } when search.StartsWithOrd(recentPages.keyword) => recentPages.GetResults(search),
 				_ => defaultSearch.GetResults(search!),
 			};

Flow.Launcher.Plugin.OneNote/VisibilityChanged.cs

@@ -0,0 +1,32 @@
+namespace Flow.Launcher.Plugin.OneNote
+{
+    public delegate void VisibilityChangedEventHandler(bool isVisible);
+    public class VisibilityChanged
+    {
+        private event VisibilityChangedEventHandler? OnVisibilityChanged;
+        private readonly PluginInitContext context;
+        public VisibilityChanged(PluginInitContext context)
+        {
+            this.context = context;
+            context.API.VisibilityChanged += OnVisibilityChangedWrap;
+        }
+
+        private void OnVisibilityChangedWrap(object _, VisibilityChangedEventArgs e)
+        {
+            if (!context.CurrentPluginMetadata.Disabled)
+            {
+                OnVisibilityChanged?.Invoke(e.IsVisible);
+            }
+        }
+        public void Subscribe(VisibilityChangedEventHandler action)
+        {
+            OnVisibilityChanged += action;
+        }
+
+        public void Dispose()
+        {
+            context.API.VisibilityChanged -= OnVisibilityChangedWrap;
+            OnVisibilityChanged = null;
+        }
+    }
+}