Merge pull request #73676 from CyrusNajmabadi/tagNode

Convert interval-tree type to a struct
dotnet · May 25, 2024 · 122dc90 · 122dc90
2 parents 6c9936c + bb87e4d
commit 122dc90
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Showing 3 changed files with 27 additions and 38 deletions.
diff --git a/src/EditorFeatures/Core/Shared/Tagging/Utilities/TagSpanIntervalTree.TagNode.cs b/src/EditorFeatures/Core/Shared/Tagging/Utilities/TagSpanIntervalTree.TagNode.cs
@@ -2,49 +2,36 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CodeAnalysis.Editor.Shared.Extensions;
 using Microsoft.VisualStudio.Text;
 using Microsoft.VisualStudio.Text.Tagging;
 
 namespace Microsoft.CodeAnalysis.Editor.Shared.Tagging;
 
 internal partial class TagSpanIntervalTree<TTag>
 {
-    private class TagNode(ITagSpan<TTag> ts, SpanTrackingMode trackingMode)
+    private readonly struct TagNode(ITagSpan<TTag> tagSpan, SpanTrackingMode trackingMode)
     {
-        public readonly TTag Tag = ts.Tag;
-        public readonly ITrackingSpan Span = ts.Span.CreateTrackingSpan(trackingMode);
-        private SnapshotSpan _snapshotSpan = ts.Span;
+        private readonly ITagSpan<TTag> _originalTagSpan = tagSpan;
+        private readonly SpanTrackingMode _trackingMode = trackingMode;
 
-        private SnapshotSpan GetSnapshotSpan(ITextSnapshot textSnapshot)
-        {
-            var localSpan = _snapshotSpan;
-            if (localSpan.Snapshot == textSnapshot)
-            {
-                return localSpan;
-            }
-            else if (localSpan.Snapshot != null)
-            {
-                _snapshotSpan = default;
-            }
-
-            return default;
-        }
+        public TTag Tag => _originalTagSpan.Tag;
 
-        internal int GetStart(ITextSnapshot textSnapshot)
-        {
-            var localSpan = this.GetSnapshotSpan(textSnapshot);
-            return localSpan.Snapshot == textSnapshot
-                ? localSpan.Start
-                : this.Span.GetStartPoint(textSnapshot);
-        }
+        public TagSpan<TTag> GetTranslatedTagSpan(ITextSnapshot textSnapshot)
+            => new(GetTranslatedSpan(textSnapshot), Tag);
 
-        internal int GetLength(ITextSnapshot textSnapshot)
+        public SnapshotSpan GetTranslatedSpan(ITextSnapshot textSnapshot)
         {
-            var localSpan = this.GetSnapshotSpan(textSnapshot);
+            var localSpan = _originalTagSpan.Span;
+
             return localSpan.Snapshot == textSnapshot
-                ? localSpan.Length
-                : this.Span.GetSpan(textSnapshot).Length;
+                ? localSpan
+                : localSpan.TranslateTo(textSnapshot, _trackingMode);
         }
+
+        public int GetStart(ITextSnapshot textSnapshot)
+            => GetTranslatedSpan(textSnapshot).Start;
+
+        public int GetLength(ITextSnapshot textSnapshot)
+            => GetTranslatedSpan(textSnapshot).Length;
     }
 }
diff --git a/src/EditorFeatures/Core/Shared/Tagging/Utilities/TagSpanIntervalTree.cs b/src/EditorFeatures/Core/Shared/Tagging/Utilities/TagSpanIntervalTree.cs
@@ -71,11 +71,11 @@ private void AppendIntersectingSpansInSortedOrder(SnapshotSpan snapshotSpan, Seg
             snapshotSpan.Start, snapshotSpan.Length, ref intersectingIntervals.AsRef(), new IntervalIntrospector(snapshot));
 
         foreach (var tagNode in intersectingIntervals)
-            result.Add(new TagSpan<TTag>(tagNode.Span.GetSpan(snapshot), tagNode.Tag));
+            result.Add(tagNode.GetTranslatedTagSpan(snapshot));
     }
 
     public IEnumerable<ITagSpan<TTag>> GetSpans(ITextSnapshot snapshot)
-        => _tree.Select(tn => new TagSpan<TTag>(tn.Span.GetSpan(snapshot), tn.Tag));
+        => _tree.Select(tn => tn.GetTranslatedTagSpan(snapshot));
 
     public bool IsEmpty()
         => _tree.IsEmpty();

diff --git a/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Collections/IntervalTree`1.cs b/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Collections/IntervalTree`1.cs
@@ -10,6 +10,7 @@
 using System.Diagnostics.CodeAnalysis;
 using Microsoft.CodeAnalysis.PooledObjects;
 using Microsoft.CodeAnalysis.Shared.Extensions;
+using Microsoft.CodeAnalysis.Text;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.Shared.Collections;
@@ -54,10 +55,11 @@ protected static bool Contains<TIntrospector>(T value, int start, int length, in
         var otherStart = start;
         var otherEnd = start + length;
 
-        var thisEnd = GetEnd(value, in introspector);
         var thisStart = introspector.GetStart(value);
+        var thisEnd = thisStart + introspector.GetLength(value);
 
-        // make sure "Contains" test to be same as what TextSpan does
+        // TODO(cyrusn): This doesn't actually seem to match what TextSpan.Contains does.  It doesn't specialize empty
+        // length in any way.  Preserving this behavior for now, but we should consider changing this.
         if (length == 0)
         {
             return thisStart <= otherStart && otherEnd < thisEnd;
@@ -72,8 +74,8 @@ private static bool IntersectsWith<TIntrospector>(T value, int start, int length
         var otherStart = start;
         var otherEnd = start + length;
 
-        var thisEnd = GetEnd(value, in introspector);
         var thisStart = introspector.GetStart(value);
+        var thisEnd = thisStart + introspector.GetLength(value);
 
         return otherStart <= thisEnd && otherEnd >= thisStart;
     }
@@ -84,13 +86,13 @@ private static bool OverlapsWith<TIntrospector>(T value, int start, int length,
         var otherStart = start;
         var otherEnd = start + length;
 
-        var thisEnd = GetEnd(value, in introspector);
         var thisStart = introspector.GetStart(value);
+        var thisEnd = thisStart + introspector.GetLength(value);
 
+        // TODO(cyrusn): This doesn't actually seem to match what TextSpan.OverlapsWith does.  It doesn't specialize empty
+        // length in any way.  Preserving this behavior for now, but we should consider changing this.
         if (length == 0)
-        {
             return thisStart < otherStart && otherStart < thisEnd;
-        }
 
         var overlapStart = Math.Max(thisStart, otherStart);
         var overlapEnd = Math.Min(thisEnd, otherEnd);