Update readme, `tokio_raw_subscriber` example, cargo fmt.

README.md

@@ -45,6 +45,7 @@ What works?
 Changelog
 --------------------
 #### [Unreleased]
+- Message (de-)serialization helpers <https://github.com/sequenceplanner/r2r/pull/74>.
 - Raw message subscribers. <https://github.com/sequenceplanner/r2r/pull/73>
 
 #### [0.8.2] - 2023-12-11

r2r/benches/deserialization.rs

@@ -1,7 +1,7 @@
 use criterion::{criterion_group, criterion_main, Criterion};
 use r2r::*;
-use rand::Rng;
 use rand::thread_rng;
+use rand::Rng;
 
 const NUM_ELEMENTS: usize = 10_000;
 const NUM_TIMES: usize = 1_000;
@@ -15,7 +15,7 @@ fn bench_ros_deserialization() {
     }
     let message = std_msgs::msg::Int32MultiArray {
         layout: std_msgs::msg::MultiArrayLayout::default(),
-        data: numbers
+        data: numbers,
     };
 
     let bytes = message.to_serialized_bytes().unwrap();
@@ -34,7 +34,7 @@ fn bench_cdr_deserialization() {
     }
     let message = std_msgs::msg::Int32MultiArray {
         layout: std_msgs::msg::MultiArrayLayout::default(),
-        data: numbers
+        data: numbers,
     };
 
     let bytes = message.to_serialized_bytes().unwrap();

r2r/examples/tokio_raw_subscriber.rs

@@ -1,6 +1,7 @@
 use futures::future;
 use futures::stream::StreamExt;
 use r2r::QosProfile;
+use r2r::WrappedTypesupport;
 use serde::{Deserialize, Serialize};
 
 #[tokio::main]
@@ -27,21 +28,28 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         }
     });
 
-    // Demonstrate that we can deserialize the raw bytes into this
-    // rust struct using the cdr crate.
+    sub.for_each(|msg| {
+        println!("got raw bytes with size: {}. deserialize...", msg.len());
+
+        // We can use the ROS typesupport to perform deserialization.
+        let ros_str = r2r::std_msgs::msg::String::from_serialized_bytes(&msg);
+
+        // Demonstrate that it is possible to also deserialize the raw
+        // bytes into a rust struct using the `cdr` crate.
         #[derive(Deserialize, Serialize, PartialEq, Debug)]
         struct OurOwnStdString {
             data: String, // the field name can be anything...
         }
-    sub.for_each(|msg| {
-        println!("got raw bytes of length {}.", msg.len());
+        let cdr_str = cdr::deserialize::<OurOwnStdString>(&msg);
 
-        if let Ok(data) = cdr::deserialize::<OurOwnStdString>(&msg) {
-            println!("contents: {:?}", data);
-        } else {
-            println!("Warning: cannot deserialize data.");
+        match (ros_str, cdr_str) {
+            (Ok(s1), Ok(s2)) => {
+                assert!(s1.data == s2.data);
+                println!("... using ros: {:?}", s1);
+                println!("... using cdr: {:?}", s2);
+            }
+            _ => println!("Error: cannot deserialize data."),
         }
-
         future::ready(())
     })
     .await;

r2r/src/msg_types.rs

@@ -1,15 +1,15 @@
 use crate::error::*;
 use r2r_msg_gen::*;
 use r2r_rcl::{
-    rosidl_action_type_support_t, rosidl_message_type_support_t, rosidl_service_type_support_t,
-    rcl_serialized_message_t,
+    rcl_serialized_message_t, rosidl_action_type_support_t, rosidl_message_type_support_t,
+    rosidl_service_type_support_t,
 };
 use serde::{Deserialize, Serialize};
 use std::boxed::Box;
+use std::cell::RefCell;
 use std::convert::TryInto;
 use std::fmt::Debug;
 use std::ops::{Deref, DerefMut};
-use std::cell::RefCell;
 
 pub mod generated_msgs {
     #![allow(clippy::all)]
@@ -78,7 +78,10 @@ pub trait WrappedTypesupport:
 
             self.copy_to_native(unsafe { msg.as_mut().expect("not null") });
 
-            let msg_buf: &mut rcl_serialized_message_t = &mut *msg_buf.as_ref().map_err(|err| Error::from_rcl_error(*err))?.borrow_mut();
+            let msg_buf: &mut rcl_serialized_message_t = &mut *msg_buf
+                .as_ref()
+                .map_err(|err| Error::from_rcl_error(*err))?
+                .borrow_mut();
 
             let result = unsafe {
                 rmw_serialize(
@@ -114,7 +117,7 @@ pub trait WrappedTypesupport:
             buffer_capacity: data.len(),
 
             // Since its read only, this should never be used ..
-            allocator: unsafe { rcutils_get_default_allocator() }
+            allocator: unsafe { rcutils_get_default_allocator() },
         };
 
         // Note From the docs of rmw_deserialize, its not clear whether this reuses
@@ -129,7 +132,7 @@ pub trait WrappedTypesupport:
         };
 
         let ret_val = if result == RCL_RET_OK as i32 {
-            Ok(Self::from_native(unsafe{ msg.as_ref().expect("not null") }))
+            Ok(Self::from_native(unsafe { msg.as_ref().expect("not null") }))
         } else {
             Err(Error::from_rcl_error(result))
         };
@@ -137,7 +140,6 @@ pub trait WrappedTypesupport:
         Self::destroy_msg(msg);
 
         ret_val
-
     }
 }
 
@@ -704,7 +706,7 @@ mod tests {
 
     #[test]
     fn test_serialization_fixed_size() {
-        let message = std_msgs::msg::Int32 { data: 10};
+        let message = std_msgs::msg::Int32 { data: 10 };
 
         let bytes = message.to_serialized_bytes().unwrap();
 
@@ -717,14 +719,13 @@ mod tests {
 
         assert_eq!(bytes, bytes_2);
         assert_eq!(bytes, bytes_3);
-
     }
 
     #[test]
     fn test_serialization_dynamic_size() {
         let message = std_msgs::msg::Int32MultiArray {
             layout: std_msgs::msg::MultiArrayLayout::default(),
-            data: vec![10, 20, 30]
+            data: vec![10, 20, 30],
         };
 
         let bytes = message.to_serialized_bytes().unwrap();
@@ -738,7 +739,6 @@ mod tests {
 
         assert_eq!(bytes, bytes_2);
         assert_eq!(bytes, bytes_3);
-
     }
 
     #[cfg(r2r__test_msgs__msg__Defaults)]

r2r_msg_gen/src/lib.rs

@@ -707,8 +707,7 @@ pub fn generate_rust_msg(module_: &str, prefix_: &str, name_: &str) -> proc_macr
                 // (see https://github.com/rust-lang/rust/issues/115010)
                 typ.lifetime = Some(syn::Lifetime::new("'static", proc_macro2::Span::call_site()));
                 quote! { pub const #const_name: #typ = #value; }
-            }
-            else if let Ok(typ) = syn::parse_str::<Box<syn::Type>>(typ) {
+            } else if let Ok(typ) = syn::parse_str::<Box<syn::Type>>(typ) {
                 // Value
                 quote! { pub const #const_name: #typ = #value; }
             } else {