Implement short-circuit to improve performance when there are no acti…

…ve diagnostic listeners

src/EventStore.Client/Common/Diagnostics/ActivitySourceExtensions.cs

@@ -32,6 +32,9 @@ public static void TraceSubscriptionEvent(
         EventStoreClientSettings settings,
         UserCredentials? userCredentials
     ) {
+	    if (source.HasNoActiveListeners())
+		    return;
+
         var parentContext = resolvedEvent.OriginalEvent.Metadata.ExtractPropagationContext();
 
         if (parentContext is null) return;
@@ -53,6 +56,9 @@ public static void TraceSubscriptionEvent(
         this ActivitySource source,
         string operationName, ActivityKind activityKind, ActivityTagsCollection? tags = null, ActivityContext? parentContext = null
     ) {
+	    if (source.HasNoActiveListeners())
+		    return null;
+
         (tags ??= new ActivityTagsCollection())
             .WithRequiredTag(TelemetryTags.Database.System, "eventstoredb")
             .WithRequiredTag(TelemetryTags.Database.Operation, operationName);
@@ -67,4 +73,6 @@ public static void TraceSubscriptionEvent(
             )
             ?.Start();
     }
+
+    static bool HasNoActiveListeners(this ActivitySource source) => !source.HasListeners();
 }

src/EventStore.Client/Common/Diagnostics/EventMetadataExtensions.cs

@@ -23,7 +23,7 @@ public static TracingMetadata ExtractTracingMetadata(this ReadOnlyMemory<byte> e
 		var reader = new Utf8JsonReader(eventMetadata.Span);
 		if (!JsonDocument.TryParseValue(ref reader, out var doc))
 			return TracingMetadata.None;
-
+	
 		using (doc) {
 			if (!doc.RootElement.TryGetProperty(TracingConstants.Metadata.TraceId, out var traceId)
 			 || !doc.RootElement.TryGetProperty(TracingConstants.Metadata.SpanId, out var spanId))