Adding QoS to subscription options (ros2#2323)

* Adding QoS to subscription options

Signed-off-by: CursedRock17 <[email protected]>

Author: CursedRock17

rclcpp/include/rclcpp/create_subscription.hpp

@@ -88,7 +88,7 @@ create_subscription(
       node_parameters,
       node_topics_interface,
       options.topic_stats_options.publish_topic,
-      qos);
+      options.topic_stats_options.qos);
 
     subscription_topic_stats =
       std::make_shared<rclcpp::topic_statistics::SubscriptionTopicStatistics>(

rclcpp/include/rclcpp/subscription_options.hpp

@@ -77,6 +77,10 @@ struct SubscriptionOptionsBase
     // Topic statistics publication period in ms. Defaults to one second.
     // Only values greater than zero are allowed.
     std::chrono::milliseconds publish_period{std::chrono::seconds(1)};
+
+    // An optional QoS which can provide topic_statistics with a stable QoS separate from
+    // the subscription's current QoS settings which could be unstable.
+    rclcpp::QoS qos = SystemDefaultsQoS();
   };
 
   TopicStatisticsOptions topic_stats_options;

rclcpp/test/rclcpp/test_subscription_options.cpp

@@ -60,14 +60,17 @@ TEST_F(TestSubscriptionOptions, topic_statistics_options_default_and_set) {
   EXPECT_EQ(options.topic_stats_options.state, rclcpp::TopicStatisticsState::NodeDefault);
   EXPECT_EQ(options.topic_stats_options.publish_topic, defaultPublishTopic);
   EXPECT_EQ(options.topic_stats_options.publish_period, 1s);
+  EXPECT_EQ(options.topic_stats_options.qos, rclcpp::SystemDefaultsQoS());
 
   options.topic_stats_options.state = rclcpp::TopicStatisticsState::Enable;
   options.topic_stats_options.publish_topic = "topic_statistics";
   options.topic_stats_options.publish_period = 5min;
+  options.topic_stats_options.qos = rclcpp::BestAvailableQoS();
 
   EXPECT_EQ(options.topic_stats_options.state, rclcpp::TopicStatisticsState::Enable);
   EXPECT_EQ(options.topic_stats_options.publish_topic, "topic_statistics");
   EXPECT_EQ(options.topic_stats_options.publish_period, 5min);
+  EXPECT_EQ(options.topic_stats_options.qos, rclcpp::BestAvailableQoS());
 }
 
 TEST_F(TestSubscriptionOptions, topic_statistics_options_node_default_mode) {