Optimize StringHelper.Concat

Singulink · Dec 8, 2023 · 70ef39a · 70ef39a
1 parent ef10093
commit 70ef39a
Showing 1 changed file with 37 additions and 30 deletions.
diff --git a/Source/Singulink.IO.FileSystem/Utilities/StringHelper.cs b/Source/Singulink.IO.FileSystem/Utilities/StringHelper.cs
@@ -1,36 +1,43 @@
 using System;
 
-namespace Singulink.IO.Utilities
+namespace Singulink.IO.Utilities;
+
+#pragma warning disable CS8500 // This takes the address of, gets the size of, or declares a pointer to a managed type
+
+internal static class StringHelper
 {
-    internal static class StringHelper
+    public static unsafe string Concat(ReadOnlySpan<char> s1, ReadOnlySpan<char> s2)
     {
-        public static unsafe string Concat(ReadOnlySpan<char> s1, ReadOnlySpan<char> s2)
-        {
-            fixed (char* p1 = s1)
-            fixed (char* p2 = s2) {
-                var data = (p1: (IntPtr)p1, p2: (IntPtr)p2, length1: s1.Length, length2: s2.Length);
-
-                return string.Create(s1.Length + s2.Length, data, (span, data) =>
-                {
-                    new ReadOnlySpan<char>((char*)data.p1, data.length1).CopyTo(span);
-                    new ReadOnlySpan<char>((char*)data.p2, data.length2).CopyTo(span.Slice(data.length1));
-                });
-            }
-        }
-
-        public static unsafe string Concat(ReadOnlySpan<char> s1, ReadOnlySpan<char> s2, ReadOnlySpan<char> s3)
-        {
-            fixed (char* p1 = s1)
-            fixed (char* p2 = s2)
-            fixed (char* p3 = s3) {
-                var data = (p1: (IntPtr)p1, p2: (IntPtr)p2, p3: (IntPtr)p3, length1: s1.Length, length2: s2.Length, length3: s3.Length);
-
-                return string.Create(s1.Length + s2.Length + s3.Length, data, (span, data) => {
-                    new ReadOnlySpan<char>((char*)data.p1, data.length1).CopyTo(span);
-                    new ReadOnlySpan<char>((char*)data.p2, data.length2).CopyTo(span = span.Slice(data.length1));
-                    new ReadOnlySpan<char>((char*)data.p3, data.length3).CopyTo(span.Slice(data.length2));
-                });
-            }
-        }
+        var p1 = &s1;
+        var p2 = &s2;
+
+        var data = (p1: (nint)p1, p2: (nint)p2);
+
+        return string.Create(s1.Length + s2.Length, data, (span, data) => {
+            var s1 = *(ReadOnlySpan<char>*)data.p1;
+            var s2 = *(ReadOnlySpan<char>*)data.p2;
+
+            s1.CopyTo(span);
+            s2.CopyTo(span.Slice(s1.Length));
+        });
+    }
+
+    public static unsafe string Concat(ReadOnlySpan<char> s1, ReadOnlySpan<char> s2, ReadOnlySpan<char> s3)
+    {
+        var p1 = &s1;
+        var p2 = &s2;
+        var p3 = &s3;
+
+        var data = (p1: (nint)p1, p2: (nint)p2, p3: (nint)p3);
+
+        return string.Create(s1.Length + s2.Length + s3.Length, data, (span, data) => {
+            var s1 = *(ReadOnlySpan<char>*)data.p1;
+            var s2 = *(ReadOnlySpan<char>*)data.p2;
+            var s3 = *(ReadOnlySpan<char>*)data.p3;
+
+            s1.CopyTo(span);
+            s2.CopyTo(span = span.Slice(s1.Length));
+            s3.CopyTo(span.Slice(s2.Length));
+        });
     }
 }