Dnae adas/generic subscriber and publisher

rclcpp/CMakeLists.txt

@@ -253,6 +253,18 @@ if(BUILD_TESTING)
     "test_msgs"
   )
   target_link_libraries(test_loaned_message ${PROJECT_NAME})
+  ament_add_gtest(test_intra_process_communication test/test_intra_process_communication.cpp
+    TIMEOUT 120)
+  if(TARGET test_intra_process_communication)
+    ament_target_dependencies(test_intra_process_communication
+      "rcl"
+      "rcl_interfaces"
+      "rmw"
+      "rosidl_typesupport_cpp"
+      "test_msgs"
+    )
+  endif()
+  target_link_libraries(test_intra_process_communication ${PROJECT_NAME})
 
   ament_add_gtest(test_node test/test_node.cpp TIMEOUT 240)
   if(TARGET test_node)

rclcpp/include/rclcpp/create_publisher.hpp

@@ -29,6 +29,46 @@
 namespace rclcpp
 {
 
+/// Create and return a publisher of the given MessageT type.
+/**
+ * The NodeT type only needs to have a method called get_node_topics_interface()
+ * which returns a shared_ptr to a NodeTopicsInterface.
+ */
+template<
+  typename MessageT = SerializedMessage,
+  typename AllocatorT = std::allocator<void>,
+  typename PublisherT = rclcpp::Publisher<MessageT, AllocatorT>,
+  typename NodeT>
+std::shared_ptr<PublisherT>
+create_publisher(
+  NodeT & node,
+  const std::string & topic_name,
+  const rosidl_message_type_support_t & type_support,
+  const rclcpp::QoS & qos,
+  const rclcpp::PublisherOptionsWithAllocator<AllocatorT> & options = (
+    rclcpp::PublisherOptionsWithAllocator<AllocatorT>()
+  )
+)
+{
+  // Extract the NodeTopicsInterface from the NodeT.
+  using rclcpp::node_interfaces::get_node_topics_interface;
+  auto node_topics = get_node_topics_interface(node);
+
+  // Create the publisher.
+  auto pub = node_topics->create_publisher(
+    topic_name,
+    rclcpp::create_publisher_factory<AllocatorT, PublisherT>(
+      options,
+      type_support),
+    qos
+  );
+
+  // Add the publisher to the node topics interface.
+  node_topics->add_publisher(pub, options.callback_group);
+
+  return std::dynamic_pointer_cast<PublisherT>(pub);
+}
+
 /// Create and return a publisher of the given MessageT type.
 /**
  * The NodeT type only needs to have a method called get_node_topics_interface()

rclcpp/include/rclcpp/create_subscription.hpp

@@ -29,6 +29,52 @@
 namespace rclcpp
 {
 
+/// Create and return a subscription of the given MessageT type.
+/**
+ * The NodeT type only needs to have a method called get_node_topics_interface()
+ * which returns a shared_ptr to a NodeTopicsInterface, or be a
+ * NodeTopicsInterface pointer itself.
+ */
+template<
+  typename CallbackT,
+  typename AllocatorT = std::allocator<void>,
+  typename CallbackMessageT =
+  typename rclcpp::subscription_traits::has_message_type<CallbackT>::type,
+  typename SubscriptionT = rclcpp::Subscription<CallbackMessageT, AllocatorT>,
+  typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<
+    CallbackMessageT,
+    AllocatorT
+  >,
+  typename NodeT>
+typename std::shared_ptr<SubscriptionT>
+create_subscription(
+  NodeT && node,
+  const std::string & topic_name,
+  const rosidl_message_type_support_t & type_support,
+  const rclcpp::QoS & qos,
+  CallbackT && callback,
+  const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options =
+  rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>(),
+  typename MessageMemoryStrategyT::SharedPtr msg_mem_strat =
+  MessageMemoryStrategyT::create_default()
+)
+{
+  using rclcpp::node_interfaces::get_node_topics_interface;
+  auto node_topics = get_node_topics_interface(std::forward<NodeT>(node));
+
+  auto factory = rclcpp::create_subscription_factory(
+    std::forward<CallbackT>(callback),
+    options,
+    msg_mem_strat,
+    type_support
+  );
+
+  auto sub = node_topics->create_subscription(topic_name, factory, qos);
+  node_topics->add_subscription(sub, options.callback_group);
+
+  return std::dynamic_pointer_cast<SubscriptionT>(sub);
+}
+
 /// Create and return a subscription of the given MessageT type.
 /**
  * The NodeT type only needs to have a method called get_node_topics_interface()