from_serialized_bytes for WrappedNativeMsgUntyped

Author: m-dahl

r2r/examples/serialization.rs

@@ -0,0 +1,31 @@
+use r2r::{WrappedNativeMsgUntyped, WrappedTypesupport};
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let msg = r2r::std_msgs::msg::String {
+        data: "Hello, world".into(),
+    };
+
+    let bytes = msg.to_serialized_bytes()?;
+
+    // bytes to "untyped" r2r msg
+    let mut native = WrappedNativeMsgUntyped::new_from("std_msgs/msg/String")?;
+    native.from_serialized_bytes(&bytes)?;
+
+    // "untyped" msg to json
+    let json = native.to_json()?;
+
+    println!("as json\n----\n{}", serde_json::to_string_pretty(&json)?);
+
+    // bytes to r2r msg.
+    let msg2 = r2r::std_msgs::msg::String::from_serialized_bytes(&bytes)?;
+
+    println!("as r2r msg\n----\n{:#?}", msg2);
+
+    // json to r2r msg
+    let msg3: r2r::std_msgs::msg::String = serde_json::from_value(json)?;
+
+    assert_eq!(msg, msg2);
+    assert_eq!(msg2, msg3);
+
+    Ok(())
+}

r2r/src/lib.rs

@@ -81,6 +81,7 @@ pub use msg_types::WrappedActionTypeSupport;
 pub use msg_types::WrappedNativeMsg as NativeMsg;
 pub use msg_types::WrappedServiceTypeSupport;
 pub use msg_types::WrappedTypesupport;
+pub use msg_types::WrappedNativeMsgUntyped;
 
 mod utils;
 pub use utils::*;

r2r/src/msg_types.rs

@@ -406,6 +406,37 @@ impl WrappedNativeMsgUntyped {
         }
     }
 
+    pub fn from_serialized_bytes(&mut self, data: &[u8]) -> Result<()> {
+        // TODO: Copy paste from above, should refactor later.
+        use r2r_rcl::*;
+
+        let msg_buf = rcl_serialized_message_t {
+            buffer: data.as_ptr() as *mut u8,
+            buffer_length: data.len(),
+            buffer_capacity: data.len(),
+
+            // Since its read only, this should never be used ..
+            allocator: unsafe { rcutils_get_default_allocator() },
+        };
+
+        // Note From the docs of rmw_deserialize, its not clear whether this reuses
+        // any part of msg_buf. However it shouldn't matter since from_native
+        // clones everything again anyway ..
+        let result = unsafe {
+            rmw_deserialize(
+                &msg_buf as *const rcl_serialized_message_t,
+                self.ts,
+                self.msg,
+            )
+        };
+
+        if result == RCL_RET_OK as i32 {
+            Ok(())
+        } else {
+            Err(Error::from_rcl_error(result))
+        }
+    }
+
     pub fn to_json(&self) -> Result<serde_json::Value> {
         let json = (self.msg_to_json)(self.msg);
         json.map_err(|serde_err| Error::SerdeError {