src: optimize trace_name allocation in Worker::Run

Author: mertcanaltin

src/node_worker.cc

@@ -296,11 +296,13 @@ size_t Worker::NearHeapLimit(void* data, size_t current_heap_limit,
 
 void Worker::Run() {
   std::string trace_name;
-  // Pre-allocate space: "[worker " (8) + thread_id (20) + "]" (1) + " " (1)
-  // + typical name (~30) = ~60 bytes. Use 64 for alignment.
-  trace_name.reserve(64);
+  std::string id = std::to_string(thread_id_.id);
+  // Pre-allocate space: "[worker " (8) + thread_id + "]" (1)
+  // + (optional: " " (1) + name)
+  trace_name.reserve(8 + id.size() + 1 +
+                     (name_.empty() ? 0 : 1 + name_.size()));
   trace_name = "[worker ";
-  trace_name += std::to_string(thread_id_.id);
+  trace_name += id;
   trace_name += "]";
   if (!name_.empty()) {
     trace_name += " ";