LibUv Networking (#65)

Projects/Server/Kestrel/CorrelationIdGenerator.cs

@@ -0,0 +1,43 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Threading;
+
+namespace Microsoft.AspNetCore.Connections
+{
+  public static class CorrelationIdGenerator
+  {
+    // Base32 encoding - in ascii sort order for easy text based sorting
+    private static readonly char[] s_encode32Chars = "0123456789ABCDEFGHIJKLMNOPQRSTUV".ToCharArray();
+
+    // Seed the _lastConnectionId for this application instance with
+    // the number of 100-nanosecond intervals that have elapsed since 12:00:00 midnight, January 1, 0001
+    // for a roughly increasing _lastId over restarts
+    private static long _lastId = DateTime.UtcNow.Ticks;
+
+    public static string GetNextId() => GenerateId(Interlocked.Increment(ref _lastId));
+
+    private static string GenerateId(long id)
+    {
+      return string.Create(13, id, (buffer, value) =>
+      {
+        char[] encode32Chars = s_encode32Chars;
+
+        buffer[12] = encode32Chars[value & 31];
+        buffer[11] = encode32Chars[(value >> 5) & 31];
+        buffer[10] = encode32Chars[(value >> 10) & 31];
+        buffer[9] = encode32Chars[(value >> 15) & 31];
+        buffer[8] = encode32Chars[(value >> 20) & 31];
+        buffer[7] = encode32Chars[(value >> 25) & 31];
+        buffer[6] = encode32Chars[(value >> 30) & 31];
+        buffer[5] = encode32Chars[(value >> 35) & 31];
+        buffer[4] = encode32Chars[(value >> 40) & 31];
+        buffer[3] = encode32Chars[(value >> 45) & 31];
+        buffer[2] = encode32Chars[(value >> 50) & 31];
+        buffer[1] = encode32Chars[(value >> 55) & 31];
+        buffer[0] = encode32Chars[(value >> 60) & 31];
+      });
+    }
+  }
+}