autoware_component_interface_utils

Features

This is a utility package that provides the following features:

• Instantiation of the wrapper class
• Registration of every interface a node creates into a queryable manifest
• Serialization of that manifest to the admission manifest document schema
• Opt-in service introspection for service and client
• Service exception for response
• Relays for topic and service
• A test helper for pinning a package’s committed manifest fragment against what a node actually registers

Design

This package provides the wrappers for the interface classes of rclcpp. The wrappers limit the usage of the original class to enforce the processing recommended by the component interface. Do not inherit the class of rclcpp, and forward or wrap the member function that is allowed to be used.

Instantiation of the wrapper class

The wrapper class requires interface information in this format.

struct SampleService
{
  using Service = sample_msgs::srv::ServiceType;
  static constexpr char name[] = "/sample/service";
};

struct SampleMessage
{
  using Message = sample_msgs::msg::MessageType;
  static constexpr char name[] = "/sample/message";
  static constexpr size_t depth = 1;
  static constexpr auto reliability = RMW_QOS_POLICY_RELIABILITY_RELIABLE;
  static constexpr auto durability = RMW_QOS_POLICY_DURABILITY_TRANSIENT_LOCAL;
};

Create the wrapper by asking the adaptor for it directly, giving the specification as an explicit template argument. This is the current style: these are non-const member functions, so the adaptor must not be declared const when they are used.

// source file
auto node = autoware::component_interface_utils::NodeAdaptor(this);
srv_ = node.create_service<SampleService>(callback);
cli_ = node.create_client<SampleService>();
pub_ = node.create_publisher<SampleMessage>();
sub_ = node.create_subscription<SampleMessage>(callback);

The adaptor also provides deducing forms that take the output variable instead of an explicit template argument (init_srv, init_cli, init_pub, init_sub). They create the same wrappers as the create_* methods above, but they are the legacy form; see Migrating from init_* for the create_* replacement of each overload.

// header file
autoware::component_interface_utils::Service<SampleService>::SharedPtr srv_;
autoware::component_interface_utils::Client<SampleService>::SharedPtr cli_;
autoware::component_interface_utils::Publisher<SampleMessage>::SharedPtr pub_;
autoware::component_interface_utils::Subscription<SampleMessage>::SharedPtr sub_;

// source file
const auto node = autoware::component_interface_utils::NodeAdaptor(this);
node.init_srv(srv_, callback);  // legacy form, prefer create_service<SampleService>(callback)
node.init_cli(cli_);            // legacy form, prefer create_client<SampleService>()
node.init_pub(pub_);            // legacy form, prefer create_publisher<SampleMessage>()
node.init_sub(sub_, callback);  // legacy form, prefer create_subscription<SampleMessage>(callback)

Migrating from init_*

Every init_* overload is the legacy form and has a create_* replacement that returns the wrapper instead of writing it into an output parameter. Both styles register the interface identically, so migrating a call site is a mechanical rewrite with no behavior change.

The init_* overloads are not removed, so existing call sites keep compiling as-is; create_* is preferred for new code, and existing call sites are expected to migrate over time.

Opt-in service introspection for service and client

This package does not trace service calls by itself. What it provides is a single node-scoped switch that turns on the standard ROS 2 service introspection for every wrapper of that node, so the wrappers do not have to be configured one by one. Each node that creates wrappers through NodeAdaptor declares the following parameter, and its value is applied to all the Service and Client wrappers that the adaptor creates.

Introspection is disabled by default, so nothing is recorded unless the parameter is set. When the mode is not off, each wrapper exposes the service event topic <service name>/_service_event, which is /sample/service/_service_event for the specification above.

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