Runtime Interface Reflection: rmw

rmw/CMakeLists.txt

@@ -20,6 +20,7 @@ endif()
 find_package(ament_cmake_ros REQUIRED)
 
 find_package(rcutils REQUIRED)
+find_package(rosidl_dynamic_typesupport REQUIRED)
 find_package(rosidl_runtime_c REQUIRED)
 
 include(cmake/configure_rmw_library.cmake)
@@ -28,6 +29,7 @@ set(rmw_sources
   "src/allocators.c"
   "src/convert_rcutils_ret_to_rmw_ret.c"
   "src/discovery_options.c"
+  "src/dynamic_message_type_support.c"
   "src/event.c"
   "src/init.c"
   "src/init_options.c"
@@ -54,6 +56,9 @@ add_library(${PROJECT_NAME} ${rmw_sources})
 target_include_directories(${PROJECT_NAME} PUBLIC
   "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
   "$<INSTALL_INTERFACE:include/${PROJECT_NAME}>")
+target_link_libraries(${PROJECT_NAME}
+  rosidl_dynamic_typesupport::rosidl_dynamic_typesupport
+)
 
 if(BUILD_TESTING AND NOT RCUTILS_DISABLE_FAULT_INJECTION)
   target_compile_definitions(${PROJECT_NAME} PUBLIC RCUTILS_ENABLE_FAULT_INJECTION)
@@ -67,6 +72,7 @@ configure_rmw_library(${PROJECT_NAME} LANGUAGE "C")
 
 ament_export_dependencies(
   rcutils
+  rosidl_dynamic_typesupport
   rosidl_runtime_c
 )
 

rmw/include/rmw/dynamic_message_type_support.h

@@ -0,0 +1,87 @@
+// Copyright 2022 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RMW__DYNAMIC_MESSAGE_TYPE_SUPPORT_H_
+#define RMW__DYNAMIC_MESSAGE_TYPE_SUPPORT_H_
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#include <rosidl_dynamic_typesupport/api/serialization_support.h>
+#include <rosidl_dynamic_typesupport/dynamic_message_type_support_struct.h>
+#include <rosidl_dynamic_typesupport/identifier.h>
+#include <rosidl_dynamic_typesupport/types.h>
+
+#include <rosidl_runtime_c/message_type_support_struct.h>
+#include <rosidl_runtime_c/type_description/type_description__struct.h>
+#include <rosidl_runtime_c/type_description/type_source__struct.h>
+
+#include "rmw/features.h"
+#include "rmw/serialized_message.h"
+#include "rmw/visibility_control.h"
+
+/// Interfaces for runtime interface reflection
+
+RMW_PUBLIC
+RMW_WARN_UNUSED
+rmw_ret_t
+rmw_take_dynamic_message(
+  const rmw_subscription_t * subscription,
+  rosidl_dynamic_typesupport_dynamic_data_t * dynamic_message,
+  bool * taken,
+  rmw_subscription_allocation_t * allocation);
+
+RMW_PUBLIC
+RMW_WARN_UNUSED
+rmw_ret_t
+rmw_take_dynamic_message_with_info(
+  const rmw_subscription_t * subscription,
+  rosidl_dynamic_typesupport_dynamic_data_t * dynamic_message,
+  bool * taken,
+  rmw_message_info_t * message_info,
+  rmw_subscription_allocation_t * allocation);
+
+RMW_PUBLIC
+RMW_WARN_UNUSED
+rmw_ret_t
+rmw_get_serialization_support(
+  const char * serialization_lib_name,
+  rosidl_dynamic_typesupport_serialization_support_t ** serialization_support);  // OUT
+
+// TODO(methylDragon): Nice to have only
+// RMW_PUBLIC
+// RMW_WARN_UNUSED
+// rmw_ret_t
+// rmw_get_dynamic_type_from_middleware(
+//   const rmw_node_t * node,
+//   const char * topic_name,
+//   const rosidl_message_type_support_t type_support,
+//   rosidl_dynamic_typesupport_dynamic_type_t * dynamic_message_type);
+//
+// RMW_PUBLIC
+// RMW_WARN_UNUSED
+// rmw_ret_t
+// rmw_get_dynamic_data_from_middleware(
+//   const rmw_node_t * node,
+//   const char * topic_name,
+//   const rosidl_message_type_support_t type_support,
+//   rosidl_dynamic_typesupport_dynamic_data_t * dynamic_message);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // RMW__DYNAMIC_MESSAGE_TYPE_SUPPORT_H_

rmw/include/rmw/features.h

@@ -46,6 +46,11 @@ typedef enum RMW_PUBLIC_TYPE rmw_feature_e
   /// `rmw_message_info_t.reception_sequence_number` is filled correctly
   /// by the rmw implementation.
   RMW_FEATURE_MESSAGE_INFO_RECEPTION_SEQUENCE_NUMBER = 1,
+  /// deferred description dynamic type rosidl_message_type_support_t structs are allowed, and the
+  /// middleware MUST populate them on type discovery
+  RMW_MIDDLEWARE_SUPPORTS_TYPE_DISCOVERY = 2,
+  /// dynamic type subscriptions will use take_dynamic_message_with_info()
+  RMW_MIDDLEWARE_CAN_TAKE_DYNAMIC_MESSAGE = 3,
 } rmw_feature_t;
 
 /// Query if a feature is supported by the rmw implementation.

rmw/include/rmw/rmw.h

@@ -106,6 +106,7 @@ extern "C"
 #include "rmw/message_sequence.h"
 #include "rmw/publisher_options.h"
 #include "rmw/qos_profiles.h"
+#include "rmw/dynamic_message_type_support.h"
 #include "rmw/subscription_options.h"
 #include "rmw/types.h"
 #include "rmw/visibility_control.h"

rmw/package.xml

@@ -19,10 +19,12 @@
   <build_depend>rcutils</build_depend>
   <!-- Only needed because CMake versions less than 3.13 don't support CMP0079 -->
   <build_depend>rosidl_runtime_c</build_depend>
+  <build_depend>rosidl_dynamic_typesupport</build_depend>
 
   <build_export_depend>rcutils</build_export_depend>
   <!-- This is required for the definition of the rosidl typesupport types -->
   <build_export_depend>rosidl_runtime_c</build_export_depend>
+  <build_export_depend>rosidl_dynamic_typesupport</build_export_depend>
 
   <test_depend>ament_cmake_gmock</test_depend>
   <test_depend>ament_lint_auto</test_depend>