Add serde support to messages (#131)

Author: nnmm

rosidl_generator_rs/cmake/rosidl_generator_rs_generate_interfaces.cmake

@@ -133,10 +133,13 @@ file(MAKE_DIRECTORY "${_output_path}")
 set(_target_suffix "__rs")
 
 set(CRATES_DEPENDENCIES "rosidl_runtime_rs = \"*\"")
+set(SERDE_FEATURES "[\"dep:serde\", \"rosidl_runtime_rs/serde\"")
 foreach(_pkg_name ${rosidl_generate_interfaces_DEPENDENCY_PACKAGE_NAMES})
   find_package(${_pkg_name} REQUIRED)
   set(CRATES_DEPENDENCIES "${CRATES_DEPENDENCIES}\n${_pkg_name} = \"*\"")
+  set(SERDE_FEATURES "${SERDE_FEATURES}, \"${_pkg_name}/serde\"")
 endforeach()
+  set(SERDE_FEATURES "${SERDE_FEATURES}]")
 ament_index_register_resource("rust_packages")
 
 

rosidl_generator_rs/resource/Cargo.toml.in

@@ -5,4 +5,8 @@ edition = "2021"
 
 [dependencies]
 libc = "0.2"
-@CRATES_DEPENDENCIES@
+serde = { version = "1", optional = true, features = ["derive"] }
+@CRATES_DEPENDENCIES@
+
+[features]
+serde = @SERDE_FEATURES@

rosidl_generator_rs/resource/msg.rs.em

@@ -10,6 +10,8 @@ from rosidl_parser.definition import UnboundedString
 from rosidl_parser.definition import UnboundedWString
 }@
 pub mod rmw {
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
   @[for subfolder, msg_spec in msg_specs]@
 @{
 type_name = msg_spec.structure.namespaced_type.name
@@ -31,6 +33,7 @@ extern "C" {
 @# it just calls the drop/fini functions of all fields
 // Corresponds to @(package_name)__@(subfolder)__@(type_name)
 #[repr(C)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 #[derive(Clone, Debug, PartialEq, PartialOrd)]
 pub struct @(type_name) {
 @[for member in msg_spec.structure.members]@
@@ -87,11 +90,14 @@ impl rosidl_runtime_rs::RmwMessage for @(type_name) where Self: Sized {
 @# ############ Idiomatic message types ############
 @# #################################################
 @# These types use standard Rust containers where possible.
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 @[for subfolder, msg_spec in msg_specs]@
 @{
 type_name = msg_spec.structure.namespaced_type.name
 }@
 
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 #[derive(Clone, Debug, PartialEq, PartialOrd)]
 pub struct @(type_name) {
 @[for member in msg_spec.structure.members]@

rosidl_runtime_rs/Cargo.toml

@@ -12,7 +12,13 @@ path = "src/lib.rs"
 [dependencies]
 # Needed for FFI
 libc = "0.2"
+# Optional dependency for making it possible to convert messages to and from
+# formats such as JSON, YAML, Pickle, etc.
+serde = { version = "1", optional = true }
 
 [dev-dependencies]
 # Needed for writing property tests
-quickcheck = "1"
+quickcheck = "1"
+# Needed for testing serde support
+serde_json = "1"
+

rosidl_runtime_rs/src/sequence.rs

@@ -4,6 +4,9 @@ use std::hash::{Hash, Hasher};
 use std::iter::{Extend, FromIterator, FusedIterator};
 use std::ops::{Deref, DerefMut};
 
+#[cfg(feature = "serde")]
+mod serde;
+
 use crate::traits::SequenceAlloc;
 
 /// An unbounded sequence.
@@ -674,7 +677,20 @@ macro_rules! seq {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use quickcheck::quickcheck;
+    use quickcheck::{quickcheck, Arbitrary, Gen};
+
+    impl<T: Arbitrary + SequenceAlloc> Arbitrary for Sequence<T> {
+        fn arbitrary(g: &mut Gen) -> Self {
+            Vec::arbitrary(g).into()
+        }
+    }
+
+    impl<T: Arbitrary + SequenceAlloc> Arbitrary for BoundedSequence<T, 256> {
+        fn arbitrary(g: &mut Gen) -> Self {
+            let len = u8::arbitrary(g);
+            (0..len).map(|_| T::arbitrary(g)).collect()
+        }
+    }
 
     quickcheck! {
         fn test_extend(xs: Vec<i32>, ys: Vec<i32>) -> bool {

rosidl_runtime_rs/src/sequence/serde.rs

@@ -0,0 +1,70 @@
+use serde::{de::Error, ser::SerializeSeq, Deserialize, Deserializer, Serialize, Serializer};
+
+use super::{BoundedSequence, Sequence};
+use crate::traits::SequenceAlloc;
+
+impl<'de, T: Deserialize<'de> + SequenceAlloc> Deserialize<'de> for Sequence<T> {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let v: Vec<_> = Deserialize::deserialize(deserializer)?;
+        Ok(Self::from(v))
+    }
+}
+
+impl<T: Serialize + SequenceAlloc> Serialize for Sequence<T> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut seq = serializer.serialize_seq(Some(self.len()))?;
+        for element in self.iter() {
+            seq.serialize_element(element)?;
+        }
+        seq.end()
+    }
+}
+
+impl<'de, T: Deserialize<'de> + SequenceAlloc, const N: usize> Deserialize<'de>
+    for BoundedSequence<T, N>
+{
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let v: Vec<_> = Deserialize::deserialize(deserializer)?;
+        Self::try_from(v).map_err(D::Error::custom)
+    }
+}
+
+impl<T: Serialize + SequenceAlloc, const N: usize> Serialize for BoundedSequence<T, N> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        self.inner.serialize(serializer)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{BoundedSequence, Sequence};
+    use quickcheck::quickcheck;
+
+    quickcheck! {
+        fn test_json_roundtrip_sequence(xs: Sequence<i32>) -> bool {
+            let value = serde_json::to_value(xs.clone()).unwrap();
+            let recovered = serde_json::from_value(value).unwrap();
+            xs == recovered
+        }
+    }
+
+    quickcheck! {
+        fn test_json_roundtrip_bounded_sequence(xs: BoundedSequence<i32, 256>) -> bool {
+            let value = serde_json::to_value(xs.clone()).unwrap();
+            let recovered = serde_json::from_value(value).unwrap();
+            xs == recovered
+        }
+    }
+}

rosidl_runtime_rs/src/string.rs

@@ -4,6 +4,9 @@ use std::fmt::{self, Debug, Display};
 use std::hash::{Hash, Hasher};
 use std::ops::{Deref, DerefMut};
 
+#[cfg(feature = "serde")]
+mod serde;
+
 use crate::sequence::Sequence;
 use crate::traits::SequenceAlloc;
 
@@ -449,3 +452,37 @@ impl Display for StringExceedsBoundsError {
 }
 
 impl std::error::Error for StringExceedsBoundsError {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use quickcheck::{Arbitrary, Gen};
+
+    impl Arbitrary for String {
+        fn arbitrary(g: &mut Gen) -> Self {
+            std::string::String::arbitrary(g).as_str().into()
+        }
+    }
+
+    impl Arbitrary for WString {
+        fn arbitrary(g: &mut Gen) -> Self {
+            std::string::String::arbitrary(g).as_str().into()
+        }
+    }
+
+    impl Arbitrary for BoundedString<256> {
+        fn arbitrary(g: &mut Gen) -> Self {
+            let len = u8::arbitrary(g);
+            let s: std::string::String = (0..len).map(|_| char::arbitrary(g)).collect();
+            s.as_str().try_into().unwrap()
+        }
+    }
+
+    impl Arbitrary for BoundedWString<256> {
+        fn arbitrary(g: &mut Gen) -> Self {
+            let len = u8::arbitrary(g);
+            let s: std::string::String = (0..len).map(|_| char::arbitrary(g)).collect();
+            s.as_str().try_into().unwrap()
+        }
+    }
+}

rosidl_runtime_rs/src/string/serde.rs

@@ -0,0 +1,120 @@
+use serde::{de::Error, Deserialize, Deserializer, Serialize, Serializer};
+use std::ops::Deref;
+
+use super::{BoundedString, BoundedWString, String, WString};
+
+impl<'de> Deserialize<'de> for String {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        std::string::String::deserialize(deserializer).map(|s| Self::from(s.as_str()))
+    }
+}
+
+impl Serialize for String {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        // Not particularly efficient
+        let s = std::string::String::from_utf8_lossy(self.deref());
+        serializer.serialize_str(&s)
+    }
+}
+
+impl<'de> Deserialize<'de> for WString {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        std::string::String::deserialize(deserializer).map(|s| Self::from(s.as_str()))
+    }
+}
+
+impl Serialize for WString {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        // Not particularly efficient
+        let s = std::string::String::from_utf16_lossy(self.deref());
+        serializer.serialize_str(&s)
+    }
+}
+
+impl<'de, const N: usize> Deserialize<'de> for BoundedString<N> {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        std::string::String::deserialize(deserializer)
+            .and_then(|s| Self::try_from(s.as_str()).map_err(D::Error::custom))
+    }
+}
+
+impl<const N: usize> Serialize for BoundedString<N> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        self.inner.serialize(serializer)
+    }
+}
+
+impl<'de, const N: usize> Deserialize<'de> for BoundedWString<N> {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        std::string::String::deserialize(deserializer)
+            .and_then(|s| Self::try_from(s.as_str()).map_err(D::Error::custom))
+    }
+}
+
+impl<const N: usize> Serialize for BoundedWString<N> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        self.inner.serialize(serializer)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{BoundedString, BoundedWString, String, WString};
+    use quickcheck::quickcheck;
+
+    quickcheck! {
+        fn test_json_roundtrip_string(s: String) -> bool {
+            let value = serde_json::to_value(s.clone()).unwrap();
+            let recovered = serde_json::from_value(value).unwrap();
+            s == recovered
+        }
+    }
+
+    quickcheck! {
+        fn test_json_roundtrip_wstring(s: WString) -> bool {
+            let value = serde_json::to_value(s.clone()).unwrap();
+            let recovered = serde_json::from_value(value).unwrap();
+            s == recovered
+        }
+    }
+
+    quickcheck! {
+        fn test_json_roundtrip_bounded_string(s: BoundedString<256>) -> bool {
+            let value = serde_json::to_value(s.clone()).unwrap();
+            let recovered = serde_json::from_value(value).unwrap();
+            s == recovered
+        }
+    }
+
+    quickcheck! {
+        fn test_json_roundtrip_bounded_wstring(s: BoundedWString<256>) -> bool {
+            let value = serde_json::to_value(s.clone()).unwrap();
+            let recovered = serde_json::from_value(value).unwrap();
+            s == recovered
+        }
+    }
+}