feat: 性能优化。

Cyjb.Markdown/Cyjb.Markdown.csproj

@@ -36,15 +36,15 @@
   </ItemGroup>
 
   <ItemGroup>
-	<PackageReference Include="Cyjb" Version="1.0.15">
+	<PackageReference Include="Cyjb" Version="1.0.17">
 	  <GeneratePathProperty>True</GeneratePathProperty>
 	</PackageReference>
-	<PackageReference Include="Cyjb.Compilers.Design" Version="1.0.15">
+	<PackageReference Include="Cyjb.Compilers.Design" Version="1.0.16">
 	  <GeneratePathProperty>True</GeneratePathProperty>
 	  <PrivateAssets>all</PrivateAssets>
 	  <IncludeAssets>compile; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 	</PackageReference>
-	<PackageReference Include="Cyjb.Compilers.Runtime" Version="1.0.15" />
+	<PackageReference Include="Cyjb.Compilers.Runtime" Version="1.0.16" />
   </ItemGroup>
 
   <ItemGroup>

Cyjb.Markdown/ParseBlock/AutoIdentifierWalker.cs

@@ -1,5 +1,5 @@
 using System.Globalization;
-using System.Text;
+using Cyjb.Collections;
 using Cyjb.Markdown.Syntax;
 using Cyjb.Markdown.Utils;
 
@@ -8,7 +8,7 @@ namespace Cyjb.Markdown.ParseBlock;
 /// <summary>
 /// 自动生成标识符的遍历器。
 /// </summary>
-internal sealed class AutoIdentifierWalker : SyntaxWalker
+internal sealed class AutoIdentifierWalker : SyntaxWalker, IDisposable
 {
 	/// <summary>
 	/// 唯一标识符。
@@ -18,10 +18,6 @@ internal sealed class AutoIdentifierWalker : SyntaxWalker
 	/// Alt 文本的渲染器。
 	/// </summary>
 	private readonly AltTextRenderer altTextRenderer = new();
-	/// <summary>
-	/// 标识符的构造器。
-	/// </summary>
-	private readonly StringBuilder identifierBuilder = new(128);
 
 	/// <summary>
 	/// 初始化 <see cref="AutoIdentifierWalker"/> 类的新实例。
@@ -49,9 +45,9 @@ public override void VisitHeading(Heading node)
 	/// </summary>
 	/// <param name="text">原始文本。</param>
 	/// <returns>从文本生成的标识符。</returns>
-	private string GetIdentifier(StringBuilder text)
+	private string GetIdentifier(ReadOnlySpan<char> text)
 	{
-		identifierBuilder.Clear();
+		using ValueList<char> identifierBuilder = new(stackalloc char[ValueList.StackallocCharSizeLimit]);
 		for (int i = 0; i < text.Length; i++)
 		{
 			char ch = text[i];
@@ -83,17 +79,18 @@ private string GetIdentifier(StringBuilder text)
 					continue;
 				}
 			}
-			identifierBuilder.Append(ch);
+			identifierBuilder.Add(ch);
 		}
-		for (; identifierBuilder.Length > 0 && IsPunctuation(identifierBuilder[^1]); identifierBuilder.Length--) ;
+		int end = identifierBuilder.Length - 1;
+		for (; end >= 0 && IsPunctuation(identifierBuilder[end]); end--) ;
 		// 7. 如果结果是空字符串，那么使用 `section` 作为标识符。
-		if (identifierBuilder.Length == 0)
+		if (end < 0)
 		{
 			return "section";
 		}
 		else
 		{
-			return identifierBuilder.ToString();
+			return identifierBuilder.AsSpan(0, end + 1).ToString();
 		}
 	}
 
@@ -130,4 +127,13 @@ private static bool IsPunctuation(char ch)
 	{
 		return ch is '_' or '-' or '.';
 	}
+
+	/// <summary>
+	/// 释放非托管资源。
+	/// </summary>
+	public void Dispose()
+	{
+		altTextRenderer.Dispose();
+		GC.SuppressFinalize(this);
+	}
 }

Cyjb.Markdown/ParseBlock/BlockLexer.cs

@@ -37,11 +37,11 @@ private void ATXHeadingWithAttributesAction()
 	{
 		if (Options.UseHeaderAttributes)
 		{
-			ReadOnlySpan<char> text = Text;
+			StringView text = Text;
 			HtmlAttributeList attrs = new();
 			if (MarkdownUtil.TryParseAttributes(ref text, attrs))
 			{
-				Text = text.ToString();
+				Text = text;
 				Accept(attrs);
 				return;
 			}
@@ -65,11 +65,11 @@ private void CodeFenceStartWithAttributesAction()
 	{
 		if (Options.UseCodeAttributes)
 		{
-			ReadOnlySpan<char> text = Text;
+			StringView text = Text;
 			HtmlAttributeList attrs = new();
 			if (MarkdownUtil.TryParseAttributes(ref text, attrs))
 			{
-				Text = text.ToString();
+				Text = text;
 				Accept(attrs);
 				return;
 			}
@@ -337,11 +337,11 @@ private void MathFenceStartWithAttributesAction()
 	{
 		if (Options.UseMath && Options.UseMathAttributes)
 		{
-			ReadOnlySpan<char> text = Text;
+			StringView text = Text;
 			HtmlAttributeList attrs = new();
 			if (MarkdownUtil.TryParseAttributes(ref text, attrs))
 			{
-				Text = text.ToString();
+				Text = text;
 				Accept(attrs);
 				return;
 			}
@@ -390,11 +390,11 @@ private void CustomContainerFenceStartWithAttributesAction()
 	{
 		if (Options.UseCustomContainers && Options.UseCustomContainerAttributes)
 		{
-			ReadOnlySpan<char> text = Text;
+			StringView text = Text;
 			HtmlAttributeList attrs = new();
 			if (MarkdownUtil.TryParseAttributes(ref text, attrs))
 			{
-				Text = text.ToString();
+				Text = text;
 				Accept(attrs);
 				return;
 			}

Cyjb.Markdown/ParseBlock/BlockParser.cs

@@ -1,3 +1,4 @@
+using System.Text;
 using Cyjb.Collections;
 using Cyjb.Markdown.ParseInline;
 using Cyjb.Markdown.Syntax;

Cyjb.Markdown/ParseBlock/IndentInfo.cs

@@ -1,4 +1,4 @@
-using System.Text;
+using Cyjb.Collections;
 using Cyjb.Text;
 
 namespace Cyjb.Markdown.ParseBlock;
@@ -23,7 +23,7 @@ internal class IndentInfo
 	/// <summary>
 	/// 缩进文本。
 	/// </summary>
-	private readonly string text;
+	private readonly StringView text;
 	/// <summary>
 	/// 原始起始位置。
 	/// </summary>
@@ -47,7 +47,7 @@ public IndentInfo(int start, LineLocator locator)
 		this.start = end = start;
 		originalStart = start;
 		this.locator = locator;
-		text = string.Empty;
+		text = StringView.Empty;
 		startColumn = endColumn = 0;
 	}
 
@@ -57,7 +57,7 @@ public IndentInfo(int start, LineLocator locator)
 	/// <param name="span">缩进文本范围。</param>
 	/// <param name="locator">行定位器。</param>
 	/// <param name="text">缩进文本。</param>
-	public IndentInfo(TextSpan span, LineLocator locator, string text)
+	public IndentInfo(TextSpan span, LineLocator locator, StringView text)
 	{
 		start = span.Start;
 		end = span.End;
@@ -131,12 +131,12 @@ public void Skip()
 	/// 返回剩余的缩进文本。
 	/// </summary>
 	/// <returns>缩进文本。</returns>
-	public string GetText()
+	public StringView GetText()
 	{
 		if (startColumn == endColumn)
 		{
 			// 所有缩进均已消费。
-			return string.Empty;
+			return StringView.Empty;
 		}
 		int column = locator.GetPosition(start).Column;
 		if (column == startColumn)
@@ -147,13 +147,13 @@ public string GetText()
 		{
 			// 当前是部分 Tab，需要使用空格补齐 column(start) 到 startColumn 的位置。
 			column = locator.GetPosition(start + 1).Column;
-			StringBuilder result = new();
-			result.Append(' ', column - startColumn);
+			using ValueList<char> result = new(stackalloc char[ValueList.StackallocCharSizeLimit]);
+			result.Add(' ', column - startColumn);
 			int idx = start + 1 - originalStart;
 			// 存在 Tab 时，可能会出现列数超出字符数的场景。
 			if (idx < text.Length)
 			{
-				result.Append(text, idx, text.Length - idx);
+				result.Add(text.AsSpan(idx));
 			}
 			return result.ToString();
 		}

Cyjb.Markdown/ParseBlock/LineInfo.cs

@@ -1,4 +1,3 @@
-using System.Text;
 using Cyjb.Collections;
 using Cyjb.Text;
 
@@ -64,6 +63,16 @@ internal LineInfo(BlockParser parser, LineLocator locator)
 		this.locator = locator;
 	}
 
+	/// <summary>
+	/// 返回指定索引的行列位置。
+	/// </summary>
+	/// <param name="index">要检查行列位置的索引。</param>
+	/// <returns>指定索引的行列位置。</returns>
+	public LinePosition GetPosition(int index)
+	{
+		return locator.GetPosition(index);
+	}
+
 	/// <summary>
 	/// 获取当前缩进宽度。
 	/// </summary>
@@ -106,15 +115,22 @@ public MappedText Text
 		{
 			if (text == null)
 			{
-				StringBuilder builder = new();
+				List<StringView> texts = new();
+				int length = 0;
+				int lastLength = 0;
+				int lastMappedIndex = 0;
 				TextSpanBuilder spanBuilder = new();
-				List<Tuple<int, int>> map = new();
+				List<Tuple<int, int>> maps = new();
 				// 添加缩进。
 				if (indent != null && indent.Width > 0)
 				{
-					map.Add(new Tuple<int, int>(0, indent.Start));
-					spanBuilder.Add(indent.Start);
-					builder.Append(indent.GetText());
+					lastMappedIndex = indent.Start;
+					maps.Add(new Tuple<int, int>(0, lastMappedIndex));
+					spanBuilder.Add(lastMappedIndex);
+					StringView text = indent.GetText();
+					lastLength = text.Length;
+					length += lastLength;
+					texts.Add(text);
 				}
 				// 添加剩余词法单元。
 				bool isFirst = true;
@@ -123,13 +139,20 @@ public MappedText Text
 					// 首个缩进可能会存在 Tab 部分替换为空格的情况，因此之后的词法单元也需要添加索引。
 					if (isFirst)
 					{
-						map.Add(new Tuple<int, int>(builder.Length, token.Span.Start));
+						int offset = token.Span.Start - lastMappedIndex;
+						if (lastLength != offset)
+						{
+							maps.Add(new Tuple<int, int>(lastLength, offset));
+						}
 						isFirst = false;
 					}
-					builder.Append(token.Text);
+					lastMappedIndex = token.Span.Start;
+					lastLength = token.Text.Length;
+					length += lastLength;
+					texts.Add(token.Text);
 					spanBuilder.Add(token.Span);
 				}
-				text = new MappedText(builder.ToString(), spanBuilder.GetSpan(), map.ToArray());
+				text = new MappedText(texts, length, spanBuilder.GetSpan(), maps);
 			}
 			return text;
 		}