[20156] Feature: topic keys

rosidl_parser/rosidl_parser/definition.py

@@ -508,6 +508,15 @@ def __init__(self, namespaced_type: NamespacedType, members=None):
         self.namespaced_type = namespaced_type
         self.members = members or []
 
+    def has_any_member_with_annotation(self, name: str):
+        """
+        Returns whether any member has a particular annotation.
+
+        :param name: the annotation name
+        """
+        has_any = [member.name for member in self.members if member.has_annotation(name)]
+        return bool(has_any)
+
 
 class Include:
     """An include statement."""

rosidl_typesupport_introspection_c/include/rosidl_typesupport_introspection_c/message_introspection.h

@@ -39,6 +39,8 @@ typedef struct rosidl_typesupport_introspection_c__MessageMember_s
   /// If the type_id_ value is rosidl_typesupport_introspection_c__ROS_TYPE_MESSAGE,
   /// this points to an array describing the fields of the sub-interface.
   const rosidl_message_type_support_t * members_;
+  /// True if this field is a keyed field, false otherwise.
+  bool is_key_;
   /// True if this field is an array type, false if it is any other type. An
   /// array has the same value for / type_id_.
   bool is_array_;

rosidl_typesupport_introspection_c/resource/msg__type_support.c.em

@@ -238,6 +238,8 @@ for index, member in enumerate(message.structure.members):
         print('    0,  // upper bound of string')
         # const rosidl_message_type_support_t * members_
         print('    NULL,  // members of sub message (initialized later)')
+    # bool is_key_
+    print('    %s,  // is key' % ('true' if member.has_annotation('key') else 'false'))
     # bool is_array_
     print('    %s,  // is array' % ('true' if isinstance(member.type, AbstractNestedType) else 'false'))
     # size_t array_size_

rosidl_typesupport_introspection_cpp/include/rosidl_typesupport_introspection_cpp/message_introspection.hpp

@@ -41,6 +41,8 @@ typedef struct ROSIDL_TYPESUPPORT_INTROSPECTION_CPP_PUBLIC MessageMember_s
   /// If the type_id_ value is rosidl_typesupport_introspection_cpp::ROS_TYPE_MESSAGE
   /// this points to an array describing the fields of the sub-interface.
   const rosidl_message_type_support_t * members_;
+  /// True if this field is a keyed field, false otherwise.
+  bool is_key_;
   /// True if this field is an array, false if it is a unary type. An array has the same value for
   /// type_id_.
   bool is_array_;

rosidl_typesupport_introspection_cpp/resource/msg__type_support.cpp.em

@@ -204,6 +204,8 @@ for index, member in enumerate(message.structure.members):
         print('    0,  // upper bound of string')
         # const rosidl_message_type_support_t * members_
         print('    ::rosidl_typesupport_introspection_cpp::get_message_type_support_handle<%s>(),  // members of sub message' % '::'.join(type_.namespaced_name()))
+    # bool is_key_
+    print('    %s,  // is key' % ('true' if member.has_annotation('key') else 'false'))
     # bool is_array_
     print('    %s,  // is array' % ('true' if isinstance(member.type, AbstractNestedType) else 'false'))
     # size_t array_size_