save progress

src/Scanner/__Libraries/StellaOps.Scanner.ReachabilityDrift/DeterministicIds.cs

@@ -0,0 +1,41 @@
+using System.Security.Cryptography;
+using System.Text;
+
+namespace StellaOps.Scanner.ReachabilityDrift;
+
+internal static class DeterministicIds
+{
+    internal static readonly Guid CodeChangeNamespace = new("a420df67-6c4b-4f80-9870-0d070a845b4b");
+    internal static readonly Guid DriftResultNamespace = new("c60e2a63-9bc4-4ff0-9f8c-2a7c11c2f8c4");
+    internal static readonly Guid DriftedSinkNamespace = new("9b8ed5d2-4b6f-4f6f-9e3b-3a81e9f85a25");
+
+    public static Guid Create(Guid namespaceId, params string[] segments)
+    {
+        var normalized = string.Join(
+            '|',
+            segments.Select(static s => (s ?? string.Empty).Trim()));
+        return Create(namespaceId, Encoding.UTF8.GetBytes(normalized));
+    }
+
+    public static Guid Create(Guid namespaceId, ReadOnlySpan<byte> nameBytes)
+    {
+        Span<byte> namespaceBytes = stackalloc byte[16];
+        namespaceId.TryWriteBytes(namespaceBytes);
+
+        Span<byte> buffer = stackalloc byte[namespaceBytes.Length + nameBytes.Length];
+        namespaceBytes.CopyTo(buffer);
+        nameBytes.CopyTo(buffer[namespaceBytes.Length..]);
+
+        Span<byte> hash = stackalloc byte[32];
+        SHA256.TryHashData(buffer, hash, out _);
+
+        Span<byte> guidBytes = stackalloc byte[16];
+        hash[..16].CopyTo(guidBytes);
+
+        guidBytes[6] = (byte)((guidBytes[6] & 0x0F) | 0x50);
+        guidBytes[8] = (byte)((guidBytes[8] & 0x3F) | 0x80);
+
+        return new Guid(guidBytes);
+    }
+}
+