RSCBC-12: Add tracing::span_enabled! fast path consistently across SDK

Author: Matt-Woz

sdk/couchbase-core/src/kvclient_ops.rs

@@ -429,11 +429,6 @@ where
         Fut: Future<Output = KvResult<(Resp, u32)>> + Send,
         Resp: TraceAttributes,
     {
-        // Fast path: skip tracing overhead when no subscriber is listening
-        if !tracing::span_enabled!(tracing::Level::TRACE) {
-            return op_fn(req).await.map(|(resp, _)| resp);
-        }
-
         let result = self
             .tracing
             .orchestrate_dispatch_span(

sdk/couchbase-core/src/tracingcomponent.rs

@@ -287,6 +287,11 @@ impl TracingComponent {
         Fut: Future<Output = T> + Send,
         F: FnOnce(&T) -> EndDispatchFields + Send,
     {
+        // Fast path: skip tracing overhead when no subscriber is listening
+        if !tracing::span_enabled!(tracing::Level::TRACE) {
+            return operation.await;
+        }
+
         let span = self.create_dispatch_span(&begin_fields);
         let result = operation.instrument(span.clone()).await;
         let end_fields = end_fields_provider(&result);

sdk/couchbase/src/clients/tracing_client.rs

@@ -128,6 +128,11 @@ impl CouchbaseTracingClient {
         &self,
         f: impl FnOnce() -> crate::error::Result<T>,
     ) -> crate::error::Result<T> {
+        // Fast path: skip tracing overhead when no subscriber is listening
+        if !tracing::span_enabled!(Level::TRACE) {
+            return f();
+        }
+
         let span = trace_span!(
             target: "couchbase::tracing",
             SPAN_NAME_REQUEST_ENCODING,
@@ -152,8 +157,8 @@ impl CouchbaseTracingClient {
     ) -> OperationContext<'a> {
         let operation_name = span.name();
 
-        // Fast-path: if tracing is not enabled, avoid fetching the cluster labels.
-        let tracing_enabled = tracing::enabled!(Level::TRACE);
+        // Fast path: skip tracing overhead when no subscriber is listening
+        let tracing_enabled = tracing::span_enabled!(Level::TRACE);
 
         let cluster_labels: Option<ClusterLabels> = if tracing_enabled {
             self.get_cluster_labels().await.unwrap_or_default()