Serialized Messages with Topic Statistics (ros2#2274)

Signed-off-by: CursedRock17 <mtglucas1@gmail.com>

rclcpp/include/rclcpp/subscription.hpp

@@ -325,8 +325,20 @@ class Subscription : public SubscriptionBase
     const std::shared_ptr<rclcpp::SerializedMessage> & serialized_message,
     const rclcpp::MessageInfo & message_info) override
   {
-    // TODO(wjwwood): enable topic statistics for serialized messages
+    std::chrono::time_point<std::chrono::system_clock> now;
+    if (subscription_topic_statistics_) {
+      // get current time before executing callback to
+      // exclude callback duration from topic statistics result.
+      now = std::chrono::system_clock::now();
+    }
+
     any_callback_.dispatch(serialized_message, message_info);
+
+    if (subscription_topic_statistics_) {
+      const auto nanos = std::chrono::time_point_cast<std::chrono::nanoseconds>(now);
+      const auto time = rclcpp::Time(nanos.time_since_epoch().count());
+      subscription_topic_statistics_->handle_message(message_info.get_rmw_message_info(), time);
+    }
   }
 
   void