From fbbbc45c24c84af5941c9504d496083582efee52 Mon Sep 17 00:00:00 2001
From: Henrik <hg@impact.dk>
Date: Sun, 28 Sep 2025 23:40:50 +0200
Subject: [PATCH] Micro-optimization: Move compilation of some Regex generation
 to compile time instead of runtime, make some static ones compiled (#20287)

Move compilation of some Regex generation to compile time instead of runtime, make some static ones compiled
---
 src/Umbraco.Core/IO/ShadowFileSystem.cs       | 30 ++++++++++++++-----
 .../Templates/HtmlLocalLinkParser.cs          |  6 ++--
 .../Persistence/NPocoDatabaseExtensions.cs    |  8 +++--
 3 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/src/Umbraco.Core/IO/ShadowFileSystem.cs b/src/Umbraco.Core/IO/ShadowFileSystem.cs
index ef35006ef5..31e884454f 100644
--- a/src/Umbraco.Core/IO/ShadowFileSystem.cs
+++ b/src/Umbraco.Core/IO/ShadowFileSystem.cs
@@ -2,7 +2,7 @@ using System.Text.RegularExpressions;
 
 namespace Umbraco.Cms.Core.IO;
 
-internal sealed class ShadowFileSystem : IFileSystem
+internal sealed partial class ShadowFileSystem : IFileSystem
 {
     private readonly IFileSystem _sfs;
 
@@ -392,14 +392,28 @@ internal sealed class ShadowFileSystem : IFileSystem
     }
 
     // copied from System.Web.Util.Wildcard internal
-    internal sealed class WildcardExpression
+    internal sealed partial class WildcardExpression
     {
-        private static readonly Regex MetaRegex = new("[\\+\\{\\\\\\[\\|\\(\\)\\.\\^\\$]");
-        private static readonly Regex QuestRegex = new("\\?");
-        private static readonly Regex StarRegex = new("\\*");
-        private static readonly Regex CommaRegex = new(",");
-        private static readonly Regex SlashRegex = new("(?=/)");
-        private static readonly Regex BackslashRegex = new("(?=[\\\\:])");
+        private static readonly Regex MetaRegex = GetMetaRegex();
+
+        [GeneratedRegex("[\\+\\{\\\\\\[\\|\\(\\)\\.\\^\\$]")]
+        private static partial Regex GetMetaRegex();
+
+        private static readonly Regex QuestRegex = GetQuestRegex();
+
+        [GeneratedRegex("\\?")]
+        private static partial Regex GetQuestRegex();
+
+        private static readonly Regex StarRegex = GetStarRegex();
+
+        [GeneratedRegex("\\*")]
+        private static partial Regex GetStarRegex();
+
+        private static readonly Regex CommaRegex = GetCommaRegex();
+
+        [GeneratedRegex(",")]
+        private static partial Regex GetCommaRegex();
+
         private readonly bool _caseInsensitive;
         private readonly string _pattern;
         private Regex? _regex;
diff --git a/src/Umbraco.Core/Templates/HtmlLocalLinkParser.cs b/src/Umbraco.Core/Templates/HtmlLocalLinkParser.cs
index 73aec2e74d..468d9b462a 100644
--- a/src/Umbraco.Core/Templates/HtmlLocalLinkParser.cs
+++ b/src/Umbraco.Core/Templates/HtmlLocalLinkParser.cs
@@ -15,15 +15,15 @@ public sealed class HtmlLocalLinkParser
     // <a type="document" href="/{localLink:eed5fc6b-96fd-45a5-a0f1-b1adfb483c2f}" title="other page">other page</a>
     internal static readonly Regex LocalLinkTagPattern = new(
         @"<a.+?href=['""](?<locallink>\/?{localLink:(?<guid>[a-fA-F0-9-]+)})[^>]*?>",
-        RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace | RegexOptions.Singleline);
+        RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace | RegexOptions.Singleline | RegexOptions.Compiled);
 
     internal static readonly Regex TypePattern = new(
         """type=['"](?<type>(?:media|document))['"]""",
-        RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace);
+        RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace | RegexOptions.Compiled);
 
     internal static readonly Regex LocalLinkPattern = new(
         @"href=['""](?<locallink>\/?(?:\{|\%7B)localLink:(?<guid>[a-zA-Z0-9-://]+)(?:\}|\%7D))",
-        RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace);
+        RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace | RegexOptions.Compiled);
 
     private readonly IPublishedUrlProvider _publishedUrlProvider;
 
diff --git a/src/Umbraco.Infrastructure/Persistence/NPocoDatabaseExtensions.cs b/src/Umbraco.Infrastructure/Persistence/NPocoDatabaseExtensions.cs
index bebf59cbe7..7ad54ba16e 100644
--- a/src/Umbraco.Infrastructure/Persistence/NPocoDatabaseExtensions.cs
+++ b/src/Umbraco.Infrastructure/Persistence/NPocoDatabaseExtensions.cs
@@ -225,16 +225,18 @@ public static partial class NPocoDatabaseExtensions
     /// <returns></returns>
     public static string EscapeAtSymbols(string value)
     {
-        if (value.Contains("@") == false)
+        if (value.Contains('@') == false)
         {
             return value;
         }
 
         // this fancy regex will only match a single @ not a double, etc...
-        var regex = new Regex("(?<!@)@(?!@)");
-        return regex.Replace(value, "@@");
+        return AtRegex().Replace(value, "@@");
     }
 
+    [GeneratedRegex("(?<!@)@(?!@)")]
+    private static partial Regex AtRegex();
+
     /// <summary>
     ///     Returns the underlying connection as a typed connection - this is used to unwrap the profiled mini profiler stuff
     /// </summary>