Merge pull request #621 from MihaZupan/perf-april

April perf improvements

src/Markdig.Tests/TestLazySubstring.cs

@@ -0,0 +1,67 @@
+using Markdig.Helpers;
+using NUnit.Framework;
+
+namespace Markdig.Tests
+{
+    public class TestLazySubstring
+    {
+        [Theory]
+        [TestCase("")]
+        [TestCase("a")]
+        [TestCase("foo")]
+        public void LazySubstring_ReturnsCorrectSubstring(string text)
+        {
+            var substring = new LazySubstring(text);
+            Assert.AreEqual(0, substring.Offset);
+            Assert.AreEqual(text.Length, substring.Length);
+
+            Assert.AreEqual(text, substring.AsSpan().ToString());
+            Assert.AreEqual(text, substring.AsSpan().ToString());
+            Assert.AreEqual(0, substring.Offset);
+            Assert.AreEqual(text.Length, substring.Length);
+
+            Assert.AreSame(substring.ToString(), substring.ToString());
+            Assert.AreEqual(text, substring.ToString());
+            Assert.AreEqual(0, substring.Offset);
+            Assert.AreEqual(text.Length, substring.Length);
+
+            Assert.AreEqual(text, substring.AsSpan().ToString());
+            Assert.AreEqual(text, substring.AsSpan().ToString());
+            Assert.AreEqual(0, substring.Offset);
+            Assert.AreEqual(text.Length, substring.Length);
+        }
+
+        [Theory]
+        [TestCase("", 0, 0)]
+        [TestCase("a", 0, 0)]
+        [TestCase("a", 1, 0)]
+        [TestCase("a", 0, 1)]
+        [TestCase("foo", 1, 0)]
+        [TestCase("foo", 1, 1)]
+        [TestCase("foo", 1, 2)]
+        [TestCase("foo", 0, 3)]
+        public void LazySubstring_ReturnsCorrectSubstring(string text, int start, int length)
+        {
+            var substring = new LazySubstring(text, start, length);
+            Assert.AreEqual(start, substring.Offset);
+            Assert.AreEqual(length, substring.Length);
+
+            string expectedSubstring = text.Substring(start, length);
+
+            Assert.AreEqual(expectedSubstring, substring.AsSpan().ToString());
+            Assert.AreEqual(expectedSubstring, substring.AsSpan().ToString());
+            Assert.AreEqual(start, substring.Offset);
+            Assert.AreEqual(length, substring.Length);
+
+            Assert.AreSame(substring.ToString(), substring.ToString());
+            Assert.AreEqual(expectedSubstring, substring.ToString());
+            Assert.AreEqual(0, substring.Offset);
+            Assert.AreEqual(length, substring.Length);
+
+            Assert.AreEqual(expectedSubstring, substring.AsSpan().ToString());
+            Assert.AreEqual(expectedSubstring, substring.AsSpan().ToString());
+            Assert.AreEqual(0, substring.Offset);
+            Assert.AreEqual(length, substring.Length);
+        }
+    }
+}

src/Markdig.Tests/TestMarkdigCoreApi.cs

@@ -74,6 +74,35 @@ public void TestToHtmlWithWriter()
             }
         }
 
+        [Test]
+        public void TestDocumentToHtmlWithWriter()
+        {
+            var writer = new StringWriter();
+
+            for (int i = 0; i < 5; i++)
+            {
+                MarkdownDocument document = Markdown.Parse("This is a text with some *emphasis*");
+                document.ToHtml(writer);
+                string html = writer.ToString();
+                Assert.AreEqual("<p>This is a text with some <em>emphasis</em></p>\n", html);
+                writer.GetStringBuilder().Length = 0;
+            }
+
+            writer = new StringWriter();
+            var pipeline = new MarkdownPipelineBuilder()
+                .UseAdvancedExtensions()
+                .Build();
+
+            for (int i = 0; i < 5; i++)
+            {
+                MarkdownDocument document = Markdown.Parse("This is a text with a https://link.tld/", pipeline);
+                document.ToHtml(writer, pipeline);
+                string html = writer.ToString();
+                Assert.AreEqual("<p>This is a text with a <a href=\"https://link.tld/\">https://link.tld/</a></p>\n", html);
+                writer.GetStringBuilder().Length = 0;
+            }
+        }
+
         [Test]
         public void TestConvert()
         {

src/Markdig/Extensions/AutoLinks/AutoLinkParser.cs

@@ -49,6 +49,53 @@ public override bool Match(InlineProcessor processor, ref StringSlice slice)
                 return false;
             }
 
+            var startPosition = slice.Start;
+            int domainOffset = 0;
+
+            var c = slice.CurrentChar;
+            // Precheck URL
+            switch (c)
+            {
+                case 'h':
+                    if (slice.MatchLowercase("ttp://", 1))
+                    {
+                        domainOffset = 7; // http://
+                    }
+                    else if (slice.MatchLowercase("ttps://", 1))
+                    {
+                        domainOffset = 8; // https://
+                    }
+                    else return false;
+                    break;
+                case 'f':
+                    if (!slice.MatchLowercase("tp://", 1))
+                    {
+                        return false;
+                    }
+                    domainOffset = 6; // ftp://
+                    break;
+                case 'm':
+                    if (!slice.MatchLowercase("ailto:", 1))
+                    {
+                        return false;
+                    }
+                    break;
+                case 't':
+                    if (!slice.MatchLowercase("el:", 1))
+                    {
+                        return false;
+                    }
+                    domainOffset = 4;
+                    break;
+                case 'w':
+                    if (!slice.MatchLowercase("ww.", 1)) // We won't match http:/www. or /www.xxx
+                    {
+                        return false;
+                    }
+                    domainOffset = 4; // www.
+                    break;
+            }
+
             List<char> pendingEmphasis = _listOfCharCache.Get();
             try
             {
@@ -58,53 +105,6 @@ public override bool Match(InlineProcessor processor, ref StringSlice slice)
                     return false;
                 }
 
-                var startPosition = slice.Start;
-                int domainOffset = 0;
-
-                var c = slice.CurrentChar;
-                // Precheck URL
-                switch (c)
-                {
-                    case 'h':
-                        if (slice.MatchLowercase("ttp://", 1))
-                        {
-                            domainOffset = 7; // http://
-                        }
-                        else if (slice.MatchLowercase("ttps://", 1))
-                        {
-                            domainOffset = 8; // https://
-                        }
-                        else return false;
-                        break;
-                    case 'f':
-                        if (!slice.MatchLowercase("tp://", 1))
-                        {
-                            return false;
-                        }
-                        domainOffset = 6; // ftp://
-                        break;
-                    case 'm':
-                        if (!slice.MatchLowercase("ailto:", 1))
-                        {
-                            return false;
-                        }
-                        break;
-                    case 't':
-                        if (!slice.MatchLowercase("el:", 1))
-                        {
-                            return false;
-                        }
-                        domainOffset = 4;
-                        break;
-                    case 'w':
-                        if (!slice.MatchLowercase("ww.", 1)) // We won't match http:/www. or /www.xxx
-                        {
-                            return false;
-                        }
-                        domainOffset = 4; // www.
-                        break;
-                }
-
                 // Parse URL
                 if (!LinkHelper.TryParseUrl(ref slice, out string? link, out _, true))
                 {

src/Markdig/Extensions/Bootstrap/BootstrapExtension.cs

@@ -28,9 +28,16 @@ public void Setup(MarkdownPipeline pipeline, IMarkdownRenderer renderer)
 
         private static void PipelineOnDocumentProcessed(MarkdownDocument document)
         {
-            foreach(var node in document.Descendants())
+            foreach (var node in document.Descendants())
             {
-                if (node is Block)
+                if (node.IsInline)
+                {
+                    if (node.IsContainerInline && node is LinkInline link && link.IsImage)
+                    {
+                        link.GetAttributes().AddClass("img-fluid");
+                    }
+                }
+                else if (node.IsContainerBlock)
                 {
                     if (node is Tables.Table)
                     {
@@ -44,16 +51,12 @@ private static void PipelineOnDocumentProcessed(MarkdownDocument document)
                     {
                         node.GetAttributes().AddClass("figure");
                     }
-                    else if (node is Figures.FigureCaption)
-                    {
-                        node.GetAttributes().AddClass("figure-caption");
-                    }
                 }
-                else if (node is Inline)
+                else
                 {
-                    if (node is LinkInline link && link.IsImage)
+                    if (node is Figures.FigureCaption)
                     {
-                        link.GetAttributes().AddClass("img-fluid");
+                        node.GetAttributes().AddClass("figure-caption");
                     }
                 }
             }

src/Markdig/Helpers/ArrayHelper.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Alexandre Mutel. All rights reserved.
 // This file is licensed under the BSD-Clause 2 license. 
 // See the license.txt file in the project root for more information.
+
 namespace Markdig.Helpers
 {
     /// <summary>

src/Markdig/Helpers/BlockWrapper.cs

@@ -0,0 +1,30 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+using Markdig.Syntax;
+using System;
+
+namespace Markdig.Helpers
+{
+    // Used to avoid the overhead of type covariance checks
+    internal readonly struct BlockWrapper : IEquatable<BlockWrapper>
+    {
+        public readonly Block Block;
+
+        public BlockWrapper(Block block)
+        {
+            Block = block;
+        }
+
+        public static implicit operator Block(BlockWrapper wrapper) => wrapper.Block;
+
+        public static implicit operator BlockWrapper(Block block) => new BlockWrapper(block);
+
+        public bool Equals(BlockWrapper other) => ReferenceEquals(Block, other.Block);
+
+        public override bool Equals(object obj) => Block.Equals(obj);
+
+        public override int GetHashCode() => Block.GetHashCode();
+    }
+}

src/Markdig/Helpers/CharHelper.cs

@@ -744,7 +744,7 @@ internal static string SmallNumberToString(int number)
                 return cache[number];
             }
 
-            return number.ToString();
+            return number.ToString(CultureInfo.InvariantCulture);
         }
     }
 }

src/Markdig/Helpers/LazySubstring.cs

@@ -0,0 +1,44 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+using System;
+using System.Diagnostics;
+
+namespace Markdig.Helpers
+{
+    internal struct LazySubstring
+    {
+        private string _text;
+        public int Offset;
+        public int Length;
+
+        public LazySubstring(string text)
+        {
+            _text = text;
+            Offset = 0;
+            Length = text.Length;
+        }
+
+        public LazySubstring(string text, int offset, int length)
+        {
+            Debug.Assert((ulong)offset + (ulong)length <= (ulong)text.Length, $"{offset}-{length} in {text}");
+            _text = text;
+            Offset = offset;
+            Length = length;
+        }
+
+        public ReadOnlySpan<char> AsSpan() => _text.AsSpan(Offset, Length);
+
+        public override string ToString()
+        {
+            if (Offset != 0 || Length != _text.Length)
+            {
+                _text = _text.Substring(Offset, Length);
+                Offset = 0;
+            }
+
+            return _text;
+        }
+    }
+}

src/Markdig/Markdown.cs

@@ -132,6 +132,28 @@ public static string ToHtml(this MarkdownDocument document, MarkdownPipeline? pi
             return renderer.Writer.ToString() ?? string.Empty;
         }
 
+        /// <summary>
+        /// Converts a Markdown document to HTML.
+        /// </summary>
+        /// <param name="document">A Markdown document.</param>
+        /// <param name="writer">The destination <see cref="TextWriter"/> that will receive the result of the conversion.</param>
+        /// <param name="pipeline">The pipeline used for the conversion.</param>
+        /// <returns>The result of the conversion</returns>
+        /// <exception cref="ArgumentNullException">if markdown document variable is null</exception>
+        public static void ToHtml(this MarkdownDocument document, TextWriter writer, MarkdownPipeline? pipeline = null)
+        {
+            if (document is null) ThrowHelper.ArgumentNullException(nameof(document));
+            if (writer is null) ThrowHelper.ArgumentNullException_writer();
+
+            pipeline ??= DefaultPipeline;
+
+            using var rentedRenderer = pipeline.RentHtmlRenderer(writer);
+            HtmlRenderer renderer = rentedRenderer.Instance;
+
+            renderer.Render(document);
+            renderer.Writer.Flush();
+        }
+
         /// <summary>
         /// Converts a Markdown string to HTML and output to the specified writer.
         /// </summary>

src/Markdig/MarkdownPipeline.cs

@@ -94,7 +94,7 @@ internal RentedHtmlRenderer RentHtmlRenderer(TextWriter? writer = null)
 
         internal sealed class HtmlRendererCache : ObjectCache<HtmlRenderer>
         {
-            private static readonly TextWriter s_dummyWriter = new StringWriter();
+            private static readonly TextWriter s_dummyWriter = new FastStringWriter();
 
             private readonly MarkdownPipeline _pipeline;
             private readonly bool _customWriter;