feat(batch4-task3): implement error and rate-limit logging helpers

dotnet/src/ZB.MOM.NatsNet.Server/NatsServer.Logging.cs

@@ -171,6 +171,83 @@ public sealed partial class NatsServer
         action(logger);
     }
 
+    /// <summary>
+    /// Logs an error with a scope.
+    /// Mirrors Go <c>Server.Errors()</c>.
+    /// </summary>
+    public void Errors(object scope, Exception e)
+    {
+        ExecuteLogCall(l => l.Errorf("{0} - {1}", scope, ErrorContextHelper.UnpackIfErrorCtx(e)));
+    }
+
+    /// <summary>
+    /// Logs an error with context.
+    /// Mirrors Go <c>Server.Errorc()</c>.
+    /// </summary>
+    public void Errorc(string ctx, Exception e)
+    {
+        ExecuteLogCall(l => l.Errorf("{0}: {1}", ctx, ErrorContextHelper.UnpackIfErrorCtx(e)));
+    }
+
+    /// <summary>
+    /// Logs an error with scope and context.
+    /// Mirrors Go <c>Server.Errorsc()</c>.
+    /// </summary>
+    public void Errorsc(object scope, string ctx, Exception e)
+    {
+        ExecuteLogCall(l => l.Errorf("{0} - {1}: {2}", scope, ctx, ErrorContextHelper.UnpackIfErrorCtx(e)));
+    }
+
+    /// <summary>
+    /// Rate-limited warning based on the raw format string.
+    /// Mirrors Go <c>Server.rateLimitFormatWarnf()</c>.
+    /// </summary>
+    internal void RateLimitFormatWarnf(string format, params object[] args)
+    {
+        if (!_rateLimitLogging.TryAdd(format, DateTime.UtcNow))
+        {
+            return;
+        }
+
+        var statement = string.Format(format, args);
+        ExecuteLogCall(l => l.Warnf("{0}", statement));
+    }
+
+    /// <summary>
+    /// Rate-limited warning based on rendered statement.
+    /// Mirrors Go <c>Server.RateLimitWarnf()</c>.
+    /// </summary>
+    public void RateLimitWarnf(string format, params object[] args)
+    {
+        var statement = string.Format(format, args);
+        if (!_rateLimitLogging.TryAdd(statement, DateTime.UtcNow))
+        {
+            return;
+        }
+
+        ExecuteLogCall(l => l.Warnf("{0}", statement));
+    }
+
+    /// <summary>
+    /// Rate-limited debug logging based on rendered statement.
+    /// Mirrors Go <c>Server.RateLimitDebugf()</c>.
+    /// </summary>
+    public void RateLimitDebugf(string format, params object[] args)
+    {
+        var statement = string.Format(format, args);
+        if (!_rateLimitLogging.TryAdd(statement, DateTime.UtcNow))
+        {
+            return;
+        }
+
+        if (Interlocked.CompareExchange(ref _debugEnabled, 0, 0) == 0)
+        {
+            return;
+        }
+
+        ExecuteLogCall(l => l.Debugf("{0}", statement));
+    }
+
     private static ILogger ToMicrosoftLogger(INatsLogger? logger)
     {
         return logger switch