+200x Performance increase for huge HTML file | Refactor to TextWriter and more

src/ReverseMarkdown.Benchmark/Benchmark.md

@@ -0,0 +1,60 @@
+# Benchmark Results for ReverseMarkdown
+
+**Legends**
+
+```
+  Mean      : Arithmetic mean of all measurements
+  Error     : Half of 99.9% confidence interval
+  StdDev    : Standard deviation of all measurements
+  Gen0      : GC Generation 0 collects per 1000 operations
+  Gen1      : GC Generation 1 collects per 1000 operations
+  Gen2      : GC Generation 2 collects per 1000 operations
+  Allocated : Allocated memory per single operation (managed only, inclusive, 1KB = 1024B)
+  Ratio     : Mean of the method divided by the mean of the baseline
+  1 s       : 1 Second (1 sec)
+  1 ms      : 1 Millisecond (1 ms)
+```
+
+---
+
+## Comparing ReverseMarkdown v4.7.1 vs TextWriter approach
+
+**Hardware: AMD Ryzen 9 3900X 3.80GHz, 24 cores, 12 physical cores**
+
+```
+BenchmarkDotNet v0.15.6, Windows 11 (10.0.26200.6899)
+AMD Ryzen 9 3900X 3.80GHz, 1 CPU, 24 logical and 12 physical cores
+.NET SDK 9.0.306
+  [Host]   : .NET 9.0.10 (9.0.10, 9.0.1025.47515), X64 RyuJIT x86-64-v3
+  .NET 9.0 : .NET 9.0.10 (9.0.10, 9.0.1025.47515), X64 RyuJIT x86-64-v3
+```
+
+Job=.NET 9.0  Runtime=.NET 9.0
+
+### Running with `Files/1000-paragraphs.html` file (size: 442KB) and `1000` paragraphs.
+
+| Method                     | Mean     | Error    | StdDev   | Gen0        | Gen1       | Gen2       | Allocated | Ratio |
+|--------------------------- |---------:|---------:|---------:|------------:|-----------:|-----------:|----------:|------:|
+| ReverseMarkdown TextWriter | 25.96 ms | 0.519 ms | 0.744 ms |   3500.0000 |  1593.7500 |  1218.7500 |  24.95 MB |     1 |
+| ReverseMarkdown v4.7.1     | 147.7 ms |  2.95 ms |  8.37 ms | 100500.0000 | 97500.0000 | 97500.0000 | 896.35 MB | 5.689 |
+
+Outliers:
+- ReverseMarkdown v4.7.1: .NET 9.0 -> 2 outliers were removed (172.08 ms, 174.42 ms)
+
+### Running with `Files/10k-paragraphs.html` file (size: 3.7MB) and `10k` paragraphs.
+
+| Method                     | Mean     | Error   | StdDev  | Gen0        | Gen1        | Gen2        | Allocated | Ratio |
+|--------------------------- |---------:|--------:|--------:|------------:|------------:|------------:|----------:|------:|
+| ReverseMarkdown TextWriter |  0.232 s | 0.005 s | 0.009 s |  20000.0000 |   5000.0000 |   1000.0000 | 210.15 MB |     1 |
+| ReverseMarkdown v4.7.1     |  14.08 s | 0.280 s | 0.747 s | 624000.0000 | 605000.0000 | 603000.0000 |  75.27 GB | 60.69 |
+
+Outliers:
+- ReverseMarkdown TextWriter: .NET 9.0 -> 1 outlier  was  removed (265.53 ms)
+- ReverseMarkdown v4.7.1: .NET 9.0 -> 2 outliers were removed (17.04 s, 17.23 s)
+
+### Running with `Files/huge.html` file (size: 16MB) and `41312` paragraphs.
+
+| Method                     | Mean      | Error    | StdDev   | Gen0         | Gen1         | Gen2         | Allocated    | Ratio  |
+|--------------------------- |----------:|---------:|---------:|-------------:|-------------:|-------------:|-------------:|-------:|
+| ReverseMarkdown TextWriter |   0.944 s | 0.0175 s | 0.0172 s |   86000.0000 |   20000.0000 |    3000.0000 |    955.34 MB |      1 |
+| ReverseMarkdown v4.7.1     | 191.611 s | 3.7686 s | 4.4863 s | 2735000.0000 | 2666000.0000 | 2659000.0000 | 640544.94 MB | 202.97 |

src/ReverseMarkdown.Benchmark/CompareBenchmark.cs

@@ -0,0 +1,28 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+
+
+namespace ReverseMarkdown.Benchmark;
+
+[SimpleJob(RuntimeMoniker.Net90)]
+[RPlotExporter]
+[MemoryDiagnoser]
+public class CompareBenchmark {
+    private string _html = null!;
+    private Converter _converter = null!;
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        //_html = FileHelper.ReadFile("Files/1000-paragraphs.html");
+        _html = FileHelper.ReadFile("Files/10k-paragraphs.html");
+        _converter = new Converter(new Config());
+    }
+
+    [Benchmark]
+    public string ReverseMarkdown()
+    {
+        var result = _converter.Convert(_html);
+        return result;
+    }
+}

src/ReverseMarkdown.Benchmark/FileHelper.cs

@@ -0,0 +1,8 @@
+namespace ReverseMarkdown.Benchmark {
+    internal sealed class FileHelper {
+        public static string ReadFile(string path)
+        {
+            return File.ReadAllText(Path.Combine(AppContext.BaseDirectory, path));
+        }
+    }
+}

src/ReverseMarkdown.Benchmark/Program.cs

@@ -0,0 +1,6 @@
+using BenchmarkDotNet.Running;
+using ReverseMarkdown.Benchmark;
+
+
+var summary = BenchmarkRunner.Run<CompareBenchmark>();
+Console.ReadLine();

src/ReverseMarkdown.Benchmark/ReverseMarkdown.Benchmark.csproj

@@ -0,0 +1,32 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <Optimize>true</Optimize>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="BenchmarkDotNet" Version="0.15.6" />
+    <!--<PackageReference Include="ReverseMarkdown" Version="4.7.1" />-->
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ReverseMarkdown\ReverseMarkdown.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Update="Files\1000-paragraphs.html">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+    <None Update="Files\10k-paragraphs.html">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+    <None Update="Files\huge.html">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
+</Project>

src/ReverseMarkdown.Test/ChildConverterTests.cs

@@ -1,19 +1,13 @@
 using ReverseMarkdown.Converters;
 using ReverseMarkdown.Test.Children;
-
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
-using System.Text;
-using System.Threading.Tasks;
-
 using Xunit;
 
-namespace ReverseMarkdown.Test
-{
-    public class ChildConverterTests
-    {
+
+namespace ReverseMarkdown.Test {
+    public class ChildConverterTests {
         [Fact]
         public void WhenConverter_A_IsReplacedByConverter_IgnoreAWhenHasClass()
         {
@@ -28,7 +22,7 @@ public void WhenConverter_A_IsReplacedByConverter_IgnoreAWhenHasClass()
 
             Assert.NotNull(propValRaw);
 
-            var propVal = (IDictionary<string, IConverter>)propValRaw;
+            var propVal = (IDictionary<string, IConverter>) propValRaw;
 
             Assert.NotNull(propVal);
 

src/ReverseMarkdown.Test/Children/IgnoreAWhenHasClass.cs

@@ -1,28 +1,18 @@
 using HtmlAgilityPack;
-
 using ReverseMarkdown.Converters;
+using System.IO;
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace ReverseMarkdown.Test.Children
-{
-    internal class IgnoreAWhenHasClass : A
-    {
-        private readonly string _ignore = "ignore";
 
-        public IgnoreAWhenHasClass(Converter converter) : base(converter)
-        { }
+namespace ReverseMarkdown.Test.Children {
+    internal class IgnoreAWhenHasClass(Converter converter) : A(converter) {
+        private const string Ignore = "ignore";
 
-        public override string Convert(HtmlNode node)
+        public override void Convert(TextWriter writer, HtmlNode node)
         {
-            if (node.HasClass(_ignore))
-                return "";
+            if (node.HasClass(Ignore))
+                return;
 
-            return base.Convert(node);
+            base.Convert(writer, node);
         }
     }
 }

src/ReverseMarkdown.Test/ConverterTests.cs

@@ -55,7 +55,7 @@ public Task WhenThereIsHtmlLinkNotWhitelisted_ThenBypass()
                 @"Leave <a href=""http://example.com"">http</a>, <a href=""https://example.com"">https</a>, <a href=""ftp://example.com"">ftp</a>, <a href=""ftps://example.com"">ftps</a>, <a href=""file://example.com"">file</a>. Remove <a href=""data:text/plain;charset=UTF-8;page=21,the%20data:1234,5678"">data</a>, <a href=""tel://example.com"">tel</a> and <a href=""whatever://example.com"">whatever</a>";
             return CheckConversion(html, new Config
             {
-                WhitelistUriSchemes = new[] {"http", "https", "ftp", "ftps", "file"}
+                WhitelistUriSchemes = {"http", "https", "ftp", "ftps", "file"}
             });
         }
 
@@ -66,7 +66,7 @@ public Task WhenThereHtmlWithHrefAndNoSchema_WhitelistedEmptyString_ThenConvertT
                 html: @"<a href=""example.com"">yeah</a>",
                 config: new Config
                 {
-                    WhitelistUriSchemes = new[] {""}
+                    WhitelistUriSchemes = {""}
                 }
             );
         }
@@ -78,7 +78,7 @@ public Task WhenThereHtmlWithHrefAndNoSchema_NotWhitelisted_ThenConvertToPlain()
                 html: @"<a href=""example.com"">yeah</a>",
                 config: new Config
                 {
-                    WhitelistUriSchemes = new[] {"whatever"}
+                    WhitelistUriSchemes = {"whatever"}
                 }
             );
         }
@@ -430,7 +430,7 @@ public Task WhenThereIsImgTag_SchemeNotWhitelisted_ThenEmptyOutput()
                 html: @"<img src=""data:image/gif;base64,R0lGODlhEAAQ...""/>",
                 config: new Config
                 {
-                    WhitelistUriSchemes = new[] {"http"}
+                    WhitelistUriSchemes = {"http"}
                 }
             );
         }
@@ -442,7 +442,7 @@ public Task WhenThereIsImgTag_SchemeIsWhitelisted_ThenConvertToMarkdown()
                 html: @"<img src=""data:image/gif;base64,R0lGODlhEAAQ...""/>",
                 config: new Config()
                 {
-                    WhitelistUriSchemes = new[] {"data"}
+                    WhitelistUriSchemes = {"data"}
                 }
             );
         }
@@ -454,7 +454,7 @@ public Task WhenThereIsImgTagAndSrcWithNoSchema_WhitelistedEmptyString_ThenConve
                 html: @"<img src=""example.com""/>",
                 config: new Config()
                 {
-                    WhitelistUriSchemes = new[] {""}
+                    WhitelistUriSchemes = {""}
                 }
             );
         }
@@ -466,7 +466,7 @@ public Task WhenThereIsImgTagAndSrcWithNoSchema_NotWhitelisted_ThenConvertToPlai
                 html: @"<img src=""data:image/gif;base64,R0lGODlhEAAQ...""/>",
                 config: new Config()
                 {
-                    WhitelistUriSchemes = new[] {"whatever"}
+                    WhitelistUriSchemes = {"whatever"}
                 }
             );
         }
@@ -478,7 +478,7 @@ public Task WhenThereIsImgTagWithRelativeUrl_NotWhitelisted_ThenConvertToMarkdow
                 html: @"<img src=""/example.gif""/>",
                 config: new Config()
                 {
-                    WhitelistUriSchemes = new[] {"data"}
+                    WhitelistUriSchemes = {"data"}
                 }
             );
         }
@@ -490,7 +490,7 @@ public Task WhenThereIsImgTagWithUnixUrl_ConfigHasWhitelist_ThenConvertToMarkdow
                 html: @"<img src=""/example.gif""/>",
                 config: new Config()
                 {
-                    WhitelistUriSchemes = new[] {"file"}
+                    WhitelistUriSchemes = {"file"}
                 }
             );
         }
@@ -501,7 +501,7 @@ public Task WhenThereIsImgTagWithHttpProtocolRelativeUrl_ConfigHasWhitelist_Then
             var html = @"<img src=""//example.gif""/>";
             var config = new Config
             {
-                WhitelistUriSchemes = new[] {"http"}
+                WhitelistUriSchemes = {"http"}
             };
             return CheckConversion(html, config);
         }
@@ -1152,7 +1152,7 @@ public Task When_Tag_In_PassThoughTags_List_Then_Use_PassThroughConverter()
                 @"This text has image <img alt=""alt"" src=""http://test.com/images/test.png"">. Next line of text";
             var config = new Config
             {
-                PassThroughTags = new[] {"img"}
+                PassThroughTags = ["img"]
             };
             return CheckConversion(html, config);
         }

src/ReverseMarkdown.Test/ReverseMarkdown.Test.csproj

@@ -1,22 +1,26 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks>net472;net6.0;net9.0</TargetFrameworks>
     <IsTestProject>true</IsTestProject>
+    <LangVersion>preview</LangVersion>
   </PropertyGroup>
+
   <ItemGroup>
-    <ProjectReference Include="..\ReverseMarkdown\ReverseMarkdown.csproj" />
-    <PackageReference Include="MarkdownSnippets.MsBuild" Version="27.0.2">
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-      <PrivateAssets>all</PrivateAssets>
-    </PackageReference>
-    <PackageReference Include="Verify.Xunit" Version="30.1.0" />
+    <PackageReference Include="coverlet.collector" Version="6.0.2" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
     <PackageReference Include="xunit" Version="2.9.3" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.4">
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-      <PrivateAssets>all</PrivateAssets>
-    </PackageReference>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
+    <PackageReference Include="Verify.Xunit" Version="31.4.3" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ReverseMarkdown\ReverseMarkdown.csproj" />
   </ItemGroup>
+
   <ItemGroup>
     <None Update="ConverterTests.When_Span_with_newline_Should_Convert_Properly.verified.md">
       <DependentUpon>ConverterTests.cs</DependentUpon>

src/ReverseMarkdown.sln

@@ -1,12 +1,14 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 15
-VisualStudioVersion = 15.0.26228.9
+# Visual Studio Version 17
+VisualStudioVersion = 17.14.36616.10 d17.14
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ReverseMarkdown", "ReverseMarkdown\ReverseMarkdown.csproj", "{518A6D79-4596-4086-BA5D-DD353BCEC9A6}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ReverseMarkdown.Test", "ReverseMarkdown.Test\ReverseMarkdown.Test.csproj", "{1756FE48-2619-459C-A0D0-2D2A1D163A03}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ReverseMarkdown.Benchmark", "ReverseMarkdown.Benchmark\ReverseMarkdown.Benchmark.csproj", "{B0521F32-EA69-4ABF-8F60-89AF704ABFD4}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -21,8 +23,15 @@ Global
 		{1756FE48-2619-459C-A0D0-2D2A1D163A03}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{1756FE48-2619-459C-A0D0-2D2A1D163A03}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{1756FE48-2619-459C-A0D0-2D2A1D163A03}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B0521F32-EA69-4ABF-8F60-89AF704ABFD4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B0521F32-EA69-4ABF-8F60-89AF704ABFD4}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B0521F32-EA69-4ABF-8F60-89AF704ABFD4}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B0521F32-EA69-4ABF-8F60-89AF704ABFD4}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {478AE4EC-DF7B-46D4-9350-862EA335D02F}
+	EndGlobalSection
 EndGlobal