From 20181e4d4d7f0f99ace2be09ef1b8a68cca872a9 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Mon, 7 Nov 2022 16:08:38 +0100
Subject: [PATCH] Implement Serde traits for `ffi_safe::Vec`

---
 crates/fj/src/abi/ffi_safe.rs | 29 +++++++++++++++
 crates/fj/src/shape_2d.rs     | 66 +----------------------------------
 2 files changed, 30 insertions(+), 65 deletions(-)

diff --git a/crates/fj/src/abi/ffi_safe.rs b/crates/fj/src/abi/ffi_safe.rs
index 47dac10ab..12f51a6fa 100644
--- a/crates/fj/src/abi/ffi_safe.rs
+++ b/crates/fj/src/abi/ffi_safe.rs
@@ -127,6 +127,35 @@ impl<T> Drop for Vec<T> {
 unsafe impl<T: Send> Send for Vec<T> {}
 unsafe impl<T: Sync> Sync for Vec<T> {}
 
+#[cfg(feature = "serde")]
+impl<T> serde::ser::Serialize for Vec<T>
+where
+    T: serde::ser::Serialize,
+{
+    fn serialize<S>(
+        &self,
+        serializer: S,
+    ) -> std::result::Result<S::Ok, S::Error>
+    where
+        S: serde::ser::Serializer,
+    {
+        self.deref().serialize(serializer)
+    }
+}
+
+#[cfg(feature = "serde")]
+impl<'de, T> serde::de::Deserialize<'de> for Vec<T>
+where
+    T: serde::de::Deserialize<'de>,
+{
+    fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
+    where
+        D: serde::de::Deserializer<'de>,
+    {
+        Ok(std::vec::Vec::deserialize(deserializer)?.into())
+    }
+}
+
 /// A FFI-safe version of `Box<str>`.
 #[repr(transparent)]
 #[derive(Debug, PartialEq, Clone)]
diff --git a/crates/fj/src/shape_2d.rs b/crates/fj/src/shape_2d.rs
index 16bbf8492..fcdb6f1ce 100644
--- a/crates/fj/src/shape_2d.rs
+++ b/crates/fj/src/shape_2d.rs
@@ -169,6 +169,7 @@ impl Circle {
 
 /// A polygonal chain that is part of a [`Sketch`]
 #[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[repr(C)]
 pub struct PolyChain {
     points: ffi_safe::Vec<[f64; 2]>,
@@ -187,48 +188,6 @@ impl PolyChain {
     }
 }
 
-#[cfg(feature = "serde")]
-impl serde::ser::Serialize for PolyChain {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: serde::ser::Serializer,
-    {
-        let serde_sketch = PolyChainSerde {
-            points: self.to_points(),
-        };
-
-        serde_sketch.serialize(serializer)
-    }
-}
-
-#[cfg(feature = "serde")]
-impl<'de> serde::de::Deserialize<'de> for PolyChain {
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: serde::de::Deserializer<'de>,
-    {
-        PolyChainSerde::deserialize(deserializer)
-            .map(|serde_sketch| PolyChain::from_points(serde_sketch.points))
-    }
-}
-
-/// An owned, non-repr-C [`PolyChain`]
-///
-/// De/serializing a non-trivial structure with raw pointers is a hassle.
-/// This structure is a simple, owned intermediate form that can use the derive
-/// macros provided by serde. The implementation of the `Serialize` and
-/// `Deserialize` traits for [`PolyChain`] use this type as a stepping stone.
-///
-/// Note that constructing this requires cloning the points behind
-/// [`PolyChain`]. If de/serialization turns out to be a bottleneck, a more
-/// complete implementation will be required.
-#[cfg(feature = "serde")]
-#[derive(serde::Serialize, serde::Deserialize)]
-#[serde(rename = "Polyline")]
-struct PolyChainSerde {
-    points: Vec<[f64; 2]>,
-}
-
 impl From<Sketch> for Shape {
     fn from(shape: Sketch) -> Self {
         Self::Shape2d(shape.into())
@@ -240,26 +199,3 @@ impl From<Sketch> for Shape2d {
         Shape2d::Sketch(shape)
     }
 }
-
-#[cfg(test)]
-mod tests {
-    #[cfg(feature = "serde")]
-    #[test]
-    fn test_poly_chain_serialize_loopback() {
-        use serde_json::{from_str, to_string};
-
-        let poly_chain = super::PolyChain::from_points(vec![
-            [1.0, 1.0],
-            [2.0, 1.0],
-            [2.0, 2.0],
-            [1.0, 2.0],
-        ]);
-
-        let json = to_string(&poly_chain).expect("failed to serialize sketch");
-        let poly_chain_de: super::PolyChain =
-            from_str(&json).expect("failed to deserialize sketch");
-
-        // ensure same content
-        assert_eq!(poly_chain.to_points(), poly_chain_de.to_points());
-    }
-}