Use XxHash128

src/Cli/Microsoft.DotNet.Cli.Utils/MSBuildForwardingAppWithoutLogging.cs

@@ -149,12 +149,12 @@ public static string GetHostServerPath(bool createDirectory)
             // Most Unix systems have a maximum path length limit for Unix Domain Sockets, with Mac having a particularly short one.
             // Mac also has a generated temp directory that can be quite long, leaving very little room for the actual pipe name.
             // Fortunately, '/tmp' is mandated by POSIX to always be a valid temp directory, so we can use that instead.
-            const string dotnetServer = "dotnet-server";
+            const string dotnet = "dotnet";
             string baseDirectory = OperatingSystem.IsWindows()
-                ? Path.Join(dotnetServer, Environment.UserName) // it's not a real path on Windows, just a name
-                : Path.Join("/tmp/", dotnetServer, Environment.UserName);
+                ? Path.Join(dotnet, Environment.UserName) // it's not a real path on Windows, just a name
+                : Path.Join("/tmp/", dotnet, Environment.UserName);
 
-            string sdkPathHashed = Sha256Hasher.HashWithNormalizedCasing(AppContext.BaseDirectory);
+            string sdkPathHashed = XxHash128Hasher.HashWithNormalizedCasing(AppContext.BaseDirectory);
 
             hostServerPath = Path.Join(baseDirectory, Product.TargetFrameworkVersion, sdkPathHashed);
 

src/Cli/Microsoft.DotNet.Cli.Utils/Sha256Hasher.cs

@@ -3,6 +3,8 @@
 
 #if NET
 
+using System.Diagnostics;
+using System.IO.Hashing;
 using System.Security.Cryptography;
 
 namespace Microsoft.DotNet.Cli.Utils;
@@ -29,4 +31,17 @@ public static string HashWithNormalizedCasing(string text)
     }
 }
 
+public static class XxHash128Hasher
+{
+    public static string HashWithNormalizedCasing(string text)
+    {
+        text = text.ToUpperInvariant();
+        var bytes = Encoding.UTF8.GetBytes(text);
+        Span<byte> hash = stackalloc byte[sizeof(ulong) * 2];
+        int bytesWritten = XxHash128.Hash(bytes.AsSpan(), hash);
+        Debug.Assert(bytesWritten == hash.Length);
+        return Convert.ToHexStringLower(hash);
+    }
+}
+
 #endif