Compiler: Replace SyntaxListBuilder with PooledArrayBuilder<T> and miscellaneous performance tweaks

src/Compiler/Microsoft.AspNetCore.Razor.Language/test/DirectiveTokenEditHandlerTest.cs

@@ -7,6 +7,7 @@
 using System.Linq;
 using Microsoft.AspNetCore.Razor.Language.Legacy;
 using Microsoft.AspNetCore.Razor.Language.Syntax;
+using Microsoft.AspNetCore.Razor.PooledObjects;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Razor.Language.Test;
@@ -63,13 +64,14 @@ public void CanAcceptChange_RejectsWhitespaceChanges(int index, int length, stri
 
     private static CSharpStatementLiteralSyntax GetSyntaxNode(DirectiveTokenEditHandler editHandler, string content)
     {
-        using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var builder);
+        using PooledArrayBuilder<SyntaxToken> builder = [];
 
         var tokens = NativeCSharpLanguageCharacteristics.Instance.TokenizeString(content).ToArray();
         foreach (var token in tokens)
         {
             builder.Add((SyntaxToken)token.CreateRed());
         }
+
         var node = SyntaxFactory.CSharpStatementLiteral(builder.ToList(), SpanChunkGenerator.Null);
 
         return node.WithEditHandler(editHandler);

src/Compiler/Microsoft.AspNetCore.Razor.Language/test/Legacy/CodeBlockEditHandlerTest.cs

@@ -6,6 +6,7 @@
 using System.Linq;
 using Microsoft.AspNetCore.Razor.Language.Legacy;
 using Microsoft.AspNetCore.Razor.Language.Syntax;
+using Microsoft.AspNetCore.Razor.PooledObjects;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Razor.Language.Test.Legacy;
@@ -281,7 +282,7 @@ public void ContainsInvalidContent_ValidContent_ReturnsFalse(string content)
 
     private static SyntaxNode GetSpan(SourceLocation start, string content)
     {
-        using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var builder);
+        using PooledArrayBuilder<SyntaxToken> builder = [];
 
         var tokens = NativeCSharpLanguageCharacteristics.Instance.TokenizeString(content).ToArray();
         foreach (var token in tokens)

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/DefaultRazorIntermediateNodeLoweringPhase.cs

@@ -128,9 +128,9 @@ protected override void ExecuteCore(RazorCodeDocument codeDocument, Cancellation
             documentNode.Diagnostics.Add(diagnostic);
         }
 
-        if (imports is { IsDefault: false } importsArray)
+        if (!imports.IsDefaultOrEmpty)
         {
-            foreach (var import in importsArray)
+            foreach (var import in imports)
             {
                 foreach (var diagnostic in import.Diagnostics)
                 {
@@ -492,38 +492,30 @@ public override void VisitCSharpStatementLiteral(CSharpStatementLiteralSyntax no
             return node.GetSourceSpan(SourceDocument);
         }
 
-        protected static SyntaxList<SyntaxToken> MergeLiterals(
-            SyntaxList<SyntaxToken>? literal1,
-            SyntaxList<SyntaxToken>? literal2,
-            SyntaxList<SyntaxToken>? literal3 = null,
-            SyntaxList<SyntaxToken>? literal4 = null,
-            SyntaxList<SyntaxToken>? literal5 = null)
+        protected static SyntaxList<SyntaxToken> MergeTokenLists(params ReadOnlySpan<SyntaxList<SyntaxToken>?> tokenLists)
         {
-            using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var builder);
+            var count = 0;
 
-            if (literal1 is { } tokens1)
+            foreach (var tokenList in tokenLists)
             {
-                builder.AddRange(tokens1);
+                count += tokenList?.Count ?? 0;
             }
 
-            if (literal2 is { } tokens2)
+            if (count == 0)
             {
-                builder.AddRange(tokens2);
+                return default;
             }
 
-            if (literal3 is { } tokens3)
-            {
-                builder.AddRange(tokens3);
-            }
+            using var builder = new PooledArrayBuilder<SyntaxToken>(count);
 
-            if (literal4 is { } tokens4)
+            foreach (var tokenList in tokenLists)
             {
-                builder.AddRange(tokens4);
-            }
+                if (tokenList == null)
+                {
+                    continue;
+                }
 
-            if (literal5 is { } tokens5)
-            {
-                builder.AddRange(tokens5);
+                builder.AddRange(tokenList.GetValueOrDefault());
             }
 
             return builder.ToList();
@@ -574,7 +566,10 @@ public bool TryCast<TNode>(out ImmutableArray<TNode> result)
 
         protected static MarkupTextLiteralSyntax MergeAttributeValue(MarkupLiteralAttributeValueSyntax node)
         {
-            var valueTokens = MergeLiterals(node.Prefix?.LiteralTokens, node.Value?.LiteralTokens);
+            var valueTokens = MergeTokenLists(
+                node.Prefix?.LiteralTokens,
+                node.Value?.LiteralTokens);
+
             var rewritten = node.Prefix?.Update(valueTokens, node.Prefix.ChunkGenerator) ?? node.Value?.Update(valueTokens, node.Value.ChunkGenerator);
             rewritten = (MarkupTextLiteralSyntax)rewritten?.Green.CreateRed(node, node.Position);
 
@@ -606,12 +601,13 @@ public LegacyFileKindVisitor(DocumentIntermediateNode document, IntermediateNode
         //  Suffix="
         public override void VisitMarkupAttributeBlock(MarkupAttributeBlockSyntax node)
         {
-            var prefixTokens = MergeLiterals(
+            var prefixTokens = MergeTokenLists(
                 node.NamePrefix?.LiteralTokens,
                 node.Name.LiteralTokens,
                 node.NameSuffix?.LiteralTokens,
-                node.EqualsToken != null ? new SyntaxList<SyntaxToken>(node.EqualsToken) : default,
+                new SyntaxList<SyntaxToken>(node.EqualsToken),
                 node.ValuePrefix?.LiteralTokens);
+
             var prefix = (MarkupTextLiteralSyntax)SyntaxFactory.MarkupTextLiteral(prefixTokens, chunkGenerator: null).Green.CreateRed(node, node.NamePrefix?.Position ?? node.Name.Position);
 
             var name = node.Name.GetContent();
@@ -629,7 +625,7 @@ public override void VisitMarkupAttributeBlock(MarkupAttributeBlockSyntax node)
 
                     if (children.TryCast<MarkupLiteralAttributeValueSyntax>(out var attributeLiteralArray))
                     {
-                        using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var builder);
+                        using var builder = new PooledArrayBuilder<SyntaxToken>();
 
                         foreach (var literal in attributeLiteralArray)
                         {
@@ -639,7 +635,11 @@ public override void VisitMarkupAttributeBlock(MarkupAttributeBlockSyntax node)
 
                         var rewritten = SyntaxFactory.MarkupTextLiteral(builder.ToList(), chunkGenerator: null);
 
-                        var mergedLiterals = MergeLiterals(prefix?.LiteralTokens, rewritten.LiteralTokens, node.ValueSuffix?.LiteralTokens);
+                        var mergedLiterals = MergeTokenLists(
+                            prefix?.LiteralTokens,
+                            rewritten.LiteralTokens,
+                            node.ValueSuffix?.LiteralTokens);
+
                         var mergedAttribute = SyntaxFactory.MarkupTextLiteral(mergedLiterals, chunkGenerator: null).Green.CreateRed(node.Parent, node.Position);
                         Visit(mergedAttribute);
 
@@ -675,9 +675,10 @@ public override void VisitMarkupMinimizedAttributeBlock(MarkupMinimizedAttribute
             }
 
             // Minimized attributes are just html content.
-            var literals = MergeLiterals(
+            var literals = MergeTokenLists(
                 node.NamePrefix?.LiteralTokens,
                 node.Name?.LiteralTokens);
+
             var literal = SyntaxFactory.MarkupTextLiteral(literals, chunkGenerator: null).Green.CreateRed(node.Parent, node.Position);
 
             Visit(literal);
@@ -1188,7 +1189,7 @@ private void VisitAttributeValue(SyntaxNode node)
 
             if (children.TryCast<MarkupLiteralAttributeValueSyntax>(out var attributeLiteralArray))
             {
-                using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var builder);
+                using PooledArrayBuilder<SyntaxToken> builder = [];
 
                 foreach (var literal in attributeLiteralArray)
                 {
@@ -1201,7 +1202,7 @@ private void VisitAttributeValue(SyntaxNode node)
             }
             else if (children.TryCast<MarkupTextLiteralSyntax>(out var markupLiteralArray))
             {
-                using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var builder);
+                using PooledArrayBuilder<SyntaxToken> builder = [];
 
                 foreach (var literal in markupLiteralArray)
                 {
@@ -1213,7 +1214,7 @@ private void VisitAttributeValue(SyntaxNode node)
             }
             else if (children.TryCast<CSharpExpressionLiteralSyntax>(out var expressionLiteralArray))
             {
-                using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var builder);
+                using PooledArrayBuilder<SyntaxToken> builder = [];
 
                 SpanEditHandler editHandler = null;
                 ISpanChunkGenerator generator = null;
@@ -1244,16 +1245,16 @@ private void Combine(HtmlContentIntermediateNode node, SyntaxNode item)
                 Source = BuildSourceSpanFromNode(item),
             });
 
-            if (node.Source != null)
+            if (node.Source is SourceSpan source)
             {
                 node.Source = new SourceSpan(
-                    node.Source.Value.FilePath,
-                    node.Source.Value.AbsoluteIndex,
-                    node.Source.Value.LineIndex,
-                    node.Source.Value.CharacterIndex,
-                    node.Source.Value.Length + item.Width,
-                    node.Source.Value.LineCount,
-                    node.Source.Value.EndCharacterIndex);
+                    source.FilePath,
+                    source.AbsoluteIndex,
+                    source.LineIndex,
+                    source.CharacterIndex,
+                    source.Length + item.Width,
+                    source.LineCount,
+                    source.EndCharacterIndex);
             }
         }
     }
@@ -1298,8 +1299,8 @@ public override void VisitMarkupElement(MarkupElementSyntax node)
             if (node.StartTag != null && node.EndTag != null && node.StartTag.IsVoidElement())
             {
                 element.Diagnostics.Add(
-                        ComponentDiagnosticFactory.Create_UnexpectedClosingTagForVoidElement(
-                            BuildSourceSpanFromNode(node.EndTag), node.EndTag.GetTagNameWithOptionalBang()));
+                    ComponentDiagnosticFactory.Create_UnexpectedClosingTagForVoidElement(
+                        BuildSourceSpanFromNode(node.EndTag), node.EndTag.GetTagNameWithOptionalBang()));
             }
             else if (node.StartTag != null && node.EndTag == null && !node.StartTag.IsVoidElement() && !node.StartTag.IsSelfClosing())
             {
@@ -1388,12 +1389,13 @@ public override void VisitMarkupAttributeBlock(MarkupAttributeBlockSyntax node)
             // building Prefix and Suffix, even though we don't really use them. If we
             // end up using another node type in the future this can be simplified quite
             // a lot.
-            var prefixTokens = MergeLiterals(
+            var prefixTokens = MergeTokenLists(
                 node.NamePrefix?.LiteralTokens,
                 node.Name.LiteralTokens,
                 node.NameSuffix?.LiteralTokens,
-                node.EqualsToken == null ? new SyntaxList<SyntaxToken>() : new SyntaxList<SyntaxToken>(node.EqualsToken),
+                new SyntaxList<SyntaxToken>(node.EqualsToken),
                 node.ValuePrefix?.LiteralTokens);
+
             var prefix = (MarkupTextLiteralSyntax)SyntaxFactory.MarkupTextLiteral(prefixTokens, chunkGenerator: null).Green.CreateRed(node, node.NamePrefix?.Position ?? node.Name.Position);
 
             var name = node.Name.GetContent();
@@ -1412,7 +1414,10 @@ public override void VisitMarkupAttributeBlock(MarkupAttributeBlockSyntax node)
 
         public override void VisitMarkupMinimizedAttributeBlock(MarkupMinimizedAttributeBlockSyntax node)
         {
-            var prefixTokens = MergeLiterals(node.NamePrefix?.LiteralTokens, node.Name.LiteralTokens);
+            var prefixTokens = MergeTokenLists(
+                node.NamePrefix?.LiteralTokens,
+                node.Name.LiteralTokens);
+
             var prefix = (MarkupTextLiteralSyntax)SyntaxFactory.MarkupTextLiteral(prefixTokens, chunkGenerator: null).Green.CreateRed(node, node.NamePrefix?.Position ?? node.Name.Position);
 
             var name = node.Name.GetContent();
@@ -2158,7 +2163,7 @@ private void VisitAttributeValue(SyntaxNode node)
 
             if (children.TryCast<MarkupLiteralAttributeValueSyntax>(out var attributeLiteralArray))
             {
-                using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var valueTokens);
+                using PooledArrayBuilder<SyntaxToken> valueTokens = [];
 
                 foreach (var literal in attributeLiteralArray)
                 {
@@ -2171,7 +2176,7 @@ private void VisitAttributeValue(SyntaxNode node)
             }
             else if (children.TryCast<MarkupTextLiteralSyntax>(out var markupLiteralArray))
             {
-                using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var builder);
+                using PooledArrayBuilder<SyntaxToken> builder = [];
 
                 foreach (var literal in markupLiteralArray)
                 {
@@ -2183,7 +2188,7 @@ private void VisitAttributeValue(SyntaxNode node)
             }
             else if (children.TryCast<CSharpExpressionLiteralSyntax>(out var expressionLiteralArray))
             {
-                using var _ = SyntaxListBuilderPool.GetPooledBuilder<SyntaxToken>(out var builder);
+                using PooledArrayBuilder<SyntaxToken> builder = [];
 
                 ISpanChunkGenerator generator = null;
                 SpanEditHandler editHandler = null;
@@ -2195,7 +2200,12 @@ private void VisitAttributeValue(SyntaxNode node)
                 }
 
                 var rewritten = SyntaxFactory.CSharpExpressionLiteral(builder.ToList(), generator).Green.CreateRed(node.Parent, position);
-                rewritten = editHandler != null ? rewritten.WithEditHandler(editHandler) : rewritten;
+
+                if (editHandler != null)
+                {
+                    rewritten = rewritten.WithEditHandler(editHandler);
+                }
+
                 Visit(rewritten);
             }
             else

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Legacy/LegacySyntaxNodeExtensions.cs

@@ -164,7 +164,7 @@ public static TNode WithEditHandler<TNode>(this TNode node, SpanEditHandler? edi
 
         if (node.IsSpanKind())
         {
-            var editHandler = node.GetEditHandler() ?? SpanEditHandler.CreateDefault(AcceptedCharactersInternal.Any);
+            var editHandler = node.GetEditHandler() ?? SpanEditHandler.GetDefault(AcceptedCharactersInternal.Any);
             return editHandler.OwnsChange(node, change) ? node : null;
         }
 

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Legacy/SpanEditHandler.cs

@@ -5,22 +5,43 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Diagnostics;
-using System.Linq;
 using Microsoft.AspNetCore.Razor.Language.Syntax;
 
 namespace Microsoft.AspNetCore.Razor.Language.Legacy;
 
 internal class SpanEditHandler
 {
+    internal static readonly Func<string, IEnumerable<Syntax.InternalSyntax.SyntaxToken>> NoTokenizer = _ => [];
+
+    private static readonly ImmutableArray<SpanEditHandler> s_defaultEditHandlers =
+    [
+        // AcceptedCharactersInternal consists up of 3 bit flags.
+        // So, there are 8 possible combinations from 0 to 7.
+        CreateDefault(NoTokenizer, AcceptedCharactersInternal.None),
+        CreateDefault(NoTokenizer, (AcceptedCharactersInternal)1),
+        CreateDefault(NoTokenizer, (AcceptedCharactersInternal)2),
+        CreateDefault(NoTokenizer, (AcceptedCharactersInternal)3),
+        CreateDefault(NoTokenizer, (AcceptedCharactersInternal)4),
+        CreateDefault(NoTokenizer, (AcceptedCharactersInternal)5),
+        CreateDefault(NoTokenizer, (AcceptedCharactersInternal)6),
+        CreateDefault(NoTokenizer, (AcceptedCharactersInternal)7)
+    ];
+
     private static readonly int TypeHashCode = typeof(SpanEditHandler).GetHashCode();
 
     public required AcceptedCharactersInternal AcceptedCharacters { get; init; }
     public required Func<string, IEnumerable<Syntax.InternalSyntax.SyntaxToken>> Tokenizer { get; init; }
 
-    public static SpanEditHandler CreateDefault(AcceptedCharactersInternal acceptedCharacters)
+    public static SpanEditHandler GetDefault(AcceptedCharactersInternal acceptedCharacters)
     {
-        return CreateDefault(static c => Enumerable.Empty<Syntax.InternalSyntax.SyntaxToken>(), acceptedCharacters);
+        var index = (int)acceptedCharacters;
+
+        ArgHelper.ThrowIfNegative(index, nameof(acceptedCharacters));
+        ArgHelper.ThrowIfGreaterThanOrEqual(index, 8, nameof(acceptedCharacters));
+
+        return s_defaultEditHandlers[index];
     }
 
     public static SpanEditHandler CreateDefault(Func<string, IEnumerable<Syntax.InternalSyntax.SyntaxToken>> tokenizer, AcceptedCharactersInternal acceptedCharacters)

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Legacy/SpanEditHandlerBuilder.cs

@@ -1,18 +1,17 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// 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 System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Microsoft.AspNetCore.Razor.Language.Syntax.InternalSyntax;
 
 namespace Microsoft.AspNetCore.Razor.Language.Legacy;
 
 internal sealed class SpanEditHandlerBuilder
 {
-    private static readonly Func<string, IEnumerable<SyntaxToken>> DefaultTokenizer = static content => Enumerable.Empty<SyntaxToken>();
-    private static readonly SpanEditHandler DefaultEditHandler = SpanEditHandler.CreateDefault(AcceptedCharactersInternal.Any);
+    private static readonly Func<string, IEnumerable<SyntaxToken>> DefaultTokenizer = SpanEditHandler.NoTokenizer;
+    private static readonly SpanEditHandler DefaultEditHandler = SpanEditHandler.GetDefault(AcceptedCharactersInternal.Any);
 
     private readonly Func<string, IEnumerable<SyntaxToken>>? _defaultLanguageTokenizer;
     private readonly SpanEditHandler? _defaultLanguageEditHandler;