Improve service server ergonomics

examples/minimal_client_service/src/minimal_service.rs

@@ -3,7 +3,6 @@ use std::env;
 use anyhow::{Error, Result};
 
 fn handle_service(
-    _request_header: &rclrs::rmw_request_id_t,
     request: example_interfaces::srv::AddTwoInts_Request,
 ) -> example_interfaces::srv::AddTwoInts_Response {
     println!("request: {} + {}", request.a, request.b);
@@ -17,8 +16,8 @@ fn main() -> Result<(), Error> {
 
     let node = rclrs::create_node(&context, "minimal_service")?;
 
-    let _server = node
-        .create_service::<example_interfaces::srv::AddTwoInts, _>("add_two_ints", handle_service)?;
+    let _server =
+        node.create_service::<example_interfaces::srv::AddTwoInts>("add_two_ints", handle_service)?;
 
     println!("Starting server");
     rclrs::spin(node).map_err(|err| err.into())

rclrs/src/node.rs

@@ -263,14 +263,32 @@ impl Node {
     ///
     /// [1]: crate::Service
     // TODO: make service's lifetime depend on node's lifetime
-    pub fn create_service<T, F>(
+    pub fn create_service<T>(
         &self,
         topic: &str,
-        callback: F,
+        mut callback: impl FnMut(T::Request) -> T::Response + 'static + Send,
+    ) -> Result<Arc<Service<T>>, RclrsError>
+    where
+        T: rosidl_runtime_rs::Service,
+    {
+        let callback =
+            move |_request_header: &rmw_request_id_t, request: T::Request| callback(request);
+        self.create_service_with_header(topic, callback)
+    }
+
+    /// Creates a [`Service`][1]. Same as [`create_service`][2] but the callback
+    /// also has access to the ID of the service request.
+    ///
+    /// [1]: crate::Service
+    /// [2]: Self::create_service
+    // TODO: make service's lifetime depend on node's lifetime
+    pub fn create_service_with_header<T>(
+        &self,
+        topic: &str,
+        callback: impl FnMut(&rmw_request_id_t, T::Request) -> T::Response + 'static + Send,
     ) -> Result<Arc<Service<T>>, RclrsError>
     where
         T: rosidl_runtime_rs::Service,
-        F: Fn(&rmw_request_id_t, T::Request) -> T::Response + 'static + Send,
     {
         let service = Arc::new(Service::<T>::new(
             Arc::clone(&self.rcl_node_mtx),

rclrs/src/service.rs

@@ -47,15 +47,17 @@ pub trait ServiceBase: Send + Sync {
 }
 
 type ServiceCallback<Request, Response> =
-    Box<dyn Fn(&rmw_request_id_t, Request) -> Response + 'static + Send>;
+    Box<dyn FnMut(&rmw_request_id_t, Request) -> Response + 'static + Send>;
 
 /// Main class responsible for responding to requests sent by ROS clients.
 ///
-/// The only available way to instantiate services is via [`Node::create_service()`][1], this is to
-/// ensure that [`Node`][2]s can track all the services that have been created.
+/// The only available way to instantiate services is via [`Node::create_service()`][1] and
+/// [`Node::create_service_with_header()`][2], this is to
+/// ensure that [`Node`][3]s can track all the services that have been created.
 ///
 /// [1]: crate::Node::create_service
-/// [2]: crate::Node
+/// [2]: crate::Node::create_service_with_header
+/// [3]: crate::Node
 pub struct Service<T>
 where
     T: rosidl_runtime_rs::Service,
@@ -79,7 +81,7 @@ where
     // [`Node::create_service`], see the struct's documentation for the rationale
     where
         T: rosidl_runtime_rs::Service,
-        F: Fn(&rmw_request_id_t, T::Request) -> T::Response + 'static + Send,
+        F: FnMut(&rmw_request_id_t, T::Request) -> T::Response + 'static + Send,
     {
         // SAFETY: Getting a zero-initialized value is always safe.
         let mut rcl_service = unsafe { rcl_get_zero_initialized_service() };

rclrs_tests/src/graph_tests.rs

@@ -203,7 +203,7 @@ fn test_services() -> Result<(), RclrsError> {
     let _node_1_empty_service =
         graph
             .node1
-            .create_service::<srv::Empty, _>("graph_test_topic_4", |_, _| srv::Empty_Response {
+            .create_service::<srv::Empty>("graph_test_topic_4", |_| srv::Empty_Response {
                 structure_needs_at_least_one_member: 0,
             })?;
     let _node_2_empty_client = graph