Perf: Cache IsViewComponent results

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Extensions/INamedTypeSymbolExtensions.Cache.IsViewComponentResult.cs

@@ -0,0 +1,69 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using Microsoft.AspNetCore.Mvc.Razor.Extensions;
+
+namespace Microsoft.CodeAnalysis.Razor.Compiler.Language.Extensions;
+
+internal static partial class INamedTypeSymbolExtensions
+{
+    private sealed partial class Cache
+    {
+        private sealed class IsViewComponentResult
+        {
+            public bool IsViewComponent { get; }
+            public INamedTypeSymbol ViewComponentAttribute { get; }
+            public INamedTypeSymbol? NonViewComponentAttribute { get; }
+
+            public IsViewComponentResult(INamedTypeSymbol symbol, INamedTypeSymbol viewComponentAttribute, INamedTypeSymbol? nonViewComponentAttribute)
+            {
+                ViewComponentAttribute = viewComponentAttribute;
+                NonViewComponentAttribute = nonViewComponentAttribute;
+
+                if (symbol.DeclaredAccessibility != Accessibility.Public ||
+                    symbol.IsAbstract ||
+                    symbol.IsGenericType ||
+                    AttributeIsDefined(symbol, nonViewComponentAttribute))
+                {
+                    IsViewComponent = false;
+                }
+                else
+                {
+                    IsViewComponent = symbol.Name.EndsWith(ViewComponentTypes.ViewComponentSuffix, StringComparison.Ordinal) ||
+                        AttributeIsDefined(symbol, viewComponentAttribute);
+                }
+            }
+
+            public bool IsMatchingCache(INamedTypeSymbol viewComponentAttribute, INamedTypeSymbol? nonViewComponentAttribute)
+            {
+                return SymbolEqualityComparer.Default.Equals(ViewComponentAttribute, viewComponentAttribute)
+                    && SymbolEqualityComparer.Default.Equals(NonViewComponentAttribute, nonViewComponentAttribute);
+            }
+
+            private static bool AttributeIsDefined(INamedTypeSymbol type, INamedTypeSymbol? queryAttribute)
+            {
+                if (queryAttribute == null)
+                {
+                    return false;
+                }
+
+                var currentType = type;
+                while (currentType != null)
+                {
+                    foreach (var attribute in currentType.GetAttributes())
+                    {
+                        if (SymbolEqualityComparer.Default.Equals(attribute.AttributeClass, queryAttribute))
+                        {
+                            return true;
+                        }
+                    }
+
+                    currentType = currentType.BaseType;
+                }
+
+                return false;
+            }
+        }
+    }
+}

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Extensions/INamedTypeSymbolExtensions.Cache.cs

@@ -0,0 +1,26 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.CodeAnalysis.Razor.Compiler.Language.Extensions;
+
+internal static partial class INamedTypeSymbolExtensions
+{
+    private sealed partial class Cache(INamedTypeSymbol symbol)
+    {
+        private readonly INamedTypeSymbol _symbol = symbol;
+        private IsViewComponentResult? _isViewComponentResult;
+
+        public bool IsViewComponent(INamedTypeSymbol viewComponentAttribute, INamedTypeSymbol? nonViewComponentAttribute)
+        {
+            var isViewComponentResult = _isViewComponentResult;
+            if (isViewComponentResult is null
+                || !isViewComponentResult.IsMatchingCache(viewComponentAttribute, nonViewComponentAttribute))
+            {
+                isViewComponentResult = new IsViewComponentResult(_symbol, viewComponentAttribute, nonViewComponentAttribute);
+                _isViewComponentResult = isViewComponentResult;
+            }
+
+            return isViewComponentResult.IsViewComponent;
+        }
+    }
+}

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Extensions/INamedTypeSymbolExtensions.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Runtime.CompilerServices;
+
+namespace Microsoft.CodeAnalysis.Razor.Compiler.Language.Extensions;
+
+internal static partial class INamedTypeSymbolExtensions
+{
+    private static readonly ConditionalWeakTable<INamedTypeSymbol, Cache> s_instance = new();
+
+    public static bool IsViewComponent(this INamedTypeSymbol symbol, INamedTypeSymbol viewComponentAttribute, INamedTypeSymbol? nonViewComponentAttribute)
+    {
+        var cache = s_instance.GetValue(symbol, static s => new Cache(s));
+
+        return cache.IsViewComponent(viewComponentAttribute, nonViewComponentAttribute);
+    }
+}

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc/ViewComponentTypeVisitor.cs

@@ -3,7 +3,9 @@
 
 using System;
 using System.Collections.Generic;
+using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Razor.Compiler.Language.Extensions;
 
 namespace Microsoft.AspNetCore.Mvc.Razor.Extensions;
 
@@ -61,33 +63,6 @@ internal bool IsViewComponent(INamedTypeSymbol symbol)
             return false;
         }
 
-        if (symbol.DeclaredAccessibility != Accessibility.Public ||
-            symbol.IsAbstract ||
-            symbol.IsGenericType ||
-            AttributeIsDefined(symbol, _nonViewComponentAttribute))
-        {
-            return false;
-        }
-
-        return symbol.Name.EndsWith(ViewComponentTypes.ViewComponentSuffix, StringComparison.Ordinal) ||
-            AttributeIsDefined(symbol, _viewComponentAttribute);
-    }
-
-    private static bool AttributeIsDefined(INamedTypeSymbol? type, INamedTypeSymbol? queryAttribute)
-    {
-        if (type == null || queryAttribute == null)
-        {
-            return false;
-        }
-
-        foreach (var attribute in type.GetAttributes())
-        {
-            if (SymbolEqualityComparer.Default.Equals(attribute.AttributeClass, queryAttribute))
-            {
-                return true;
-            }
-        }
-
-        return AttributeIsDefined(type.BaseType, queryAttribute);
+        return symbol.IsViewComponent(_viewComponentAttribute, _nonViewComponentAttribute);
     }
 }