OpenDocumentGenerator: Use HashSet<DocumentKey> for unique items

Update OpenDocumentGenerator to use a dedicated HashSet instance to compute the most recent unique items. In addition, make the following changes:

- Add a DocumentSnapshot.Key property that produces a DocumentKey.
- Update OpenDocumentGenerator's async batching work queue to track DocumentKeys rather than DocumentSnapshots.
- Prefer faster boolean tests first, but checking _options.UpdateBuffersForCLosedDocuments before _projectManager.IsDocumentOpen(...)

Author: DustinCampbell

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/OpenDocumentGenerator.Comparer.cs

@@ -6,6 +6,7 @@
 using System.Collections.Immutable;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Utilities;
 using Microsoft.CodeAnalysis.Razor.Logging;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
@@ -32,21 +33,23 @@ internal partial class OpenDocumentGenerator : IRazorStartupService, IDisposable
     private readonly LanguageServerFeatureOptions _options;
     private readonly ILogger _logger;
 
-    private readonly AsyncBatchingWorkQueue<DocumentSnapshot> _workQueue;
+    private readonly AsyncBatchingWorkQueue<DocumentKey> _workQueue;
     private readonly CancellationTokenSource _disposeTokenSource;
+    private readonly HashSet<DocumentKey> _workerSet;
 
     public OpenDocumentGenerator(
         IEnumerable<IDocumentProcessedListener> listeners,
         ProjectSnapshotManager projectManager,
         LanguageServerFeatureOptions options,
         ILoggerFactory loggerFactory)
     {
-        _listeners = listeners.ToImmutableArray();
+        _listeners = [.. listeners];
         _projectManager = projectManager;
         _options = options;
 
+        _workerSet = [];
         _disposeTokenSource = new();
-        _workQueue = new AsyncBatchingWorkQueue<DocumentSnapshot>(
+        _workQueue = new AsyncBatchingWorkQueue<DocumentKey>(
             s_delay,
             ProcessBatchAsync,
             _disposeTokenSource.Token);
@@ -66,15 +69,22 @@ public void Dispose()
         _disposeTokenSource.Dispose();
     }
 
-    private async ValueTask ProcessBatchAsync(ImmutableArray<DocumentSnapshot> items, CancellationToken token)
+    private async ValueTask ProcessBatchAsync(ImmutableArray<DocumentKey> items, CancellationToken token)
     {
-        foreach (var document in items.GetMostRecentUniqueItems(Comparer.Instance))
+        _workerSet.Clear();
+
+        foreach (var key in items.GetMostRecentUniqueItems(_workerSet))
         {
             if (token.IsCancellationRequested)
             {
                 return;
             }
 
+            if (!_projectManager.TryGetDocument(key, out var document))
+            {
+                continue;
+            }
+
             var codeDocument = await document.GetGeneratedOutputAsync(token).ConfigureAwait(false);
 
             foreach (var listener in _listeners)
@@ -109,7 +119,7 @@ private void ProjectManager_Changed(object? sender, ProjectChangeEventArgs args)
                     {
                         if (newProject.TryGetDocument(documentFilePath, out var document))
                         {
-                            EnqueueIfNecessary(document);
+                            EnqueueIfNecessary(document.Key, document.Version);
                         }
                     }
 
@@ -127,11 +137,11 @@ private void ProjectManager_Changed(object? sender, ProjectChangeEventArgs args)
 
                     if (newProject.TryGetDocument(documentFilePath, out var document))
                     {
-                        EnqueueIfNecessary(document);
+                        EnqueueIfNecessary(document.Key, document.Version);
 
                         foreach (var relatedDocument in newProject.GetRelatedDocuments(document))
                         {
-                            EnqueueIfNecessary(relatedDocument);
+                            EnqueueIfNecessary(relatedDocument.Key, relatedDocument.Version);
                         }
                     }
 
@@ -152,7 +162,7 @@ private void ProjectManager_Changed(object? sender, ProjectChangeEventArgs args)
 
                             if (newProject.TryGetDocument(relatedDocumentFilePath, out var newRelatedDocument))
                             {
-                                EnqueueIfNecessary(newRelatedDocument);
+                                EnqueueIfNecessary(newRelatedDocument.Key, newRelatedDocument.Version);
                             }
                         }
                     }
@@ -167,17 +177,17 @@ private void ProjectManager_Changed(object? sender, ProjectChangeEventArgs args)
                 }
         }
 
-        void EnqueueIfNecessary(DocumentSnapshot document)
+        void EnqueueIfNecessary(DocumentKey documentKey, int documentVersion)
         {
-            if (!_projectManager.IsDocumentOpen(document.FilePath) &&
-                !_options.UpdateBuffersForClosedDocuments)
+            if (!_options.UpdateBuffersForClosedDocuments &&
+                !_projectManager.IsDocumentOpen(documentKey.FilePath))
             {
                 return;
             }
 
-            _logger.LogDebug($"Enqueuing generation of {document.FilePath} in {document.Project.Key.Id} at version {document.Version}");
+            _logger.LogDebug($"Enqueuing generation of {documentKey.FilePath} in {documentKey.ProjectKey.Id} at version {documentVersion}");
 
-            _workQueue.AddWork(document);
+            _workQueue.AddWork(documentKey);
         }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/OpenDocumentGenerator.cs

@@ -19,6 +19,7 @@ internal sealed class DocumentSnapshot(ProjectSnapshot project, DocumentState st
 
     public HostDocument HostDocument => _state.HostDocument;
 
+    public DocumentKey Key => new(Project.Key, FilePath);
     public string FileKind => _state.HostDocument.FileKind;
     public string FilePath => _state.HostDocument.FilePath;
     public string TargetPath => _state.HostDocument.TargetPath;