From 5971f6a1c4486d25486523041d22a4fbe67157ba Mon Sep 17 00:00:00 2001
From: "Augusto F. Hack" <hack.augusto@gmail.com>
Date: Fri, 1 Dec 2023 17:58:50 +0100
Subject: [PATCH] serde: add support for arrays

---
 utils/core/src/serde/mod.rs | 35 +++++++++++++++++------------------
 1 file changed, 17 insertions(+), 18 deletions(-)

diff --git a/utils/core/src/serde/mod.rs b/utils/core/src/serde/mod.rs
index 471aa96c7..3619faac1 100644
--- a/utils/core/src/serde/mod.rs
+++ b/utils/core/src/serde/mod.rs
@@ -3,7 +3,7 @@
 // This source code is licensed under the MIT license found in the
 // LICENSE file in the root directory of this source tree.
 
-use super::{flatten_slice_elements, DeserializationError, Vec};
+use super::{DeserializationError, Vec};
 
 mod byte_reader;
 pub use byte_reader::{ByteReader, SliceReader};
@@ -210,30 +210,15 @@ impl Serializable for &String {
     }
 }
 
-impl<T: Serializable, const N: usize> Serializable for Vec<[T; N]> {
-    fn write_into<W: ByteWriter>(&self, target: &mut W) {
-        let source = flatten_slice_elements(self);
-        T::write_batch_into(source, target);
-    }
-}
-
-impl<T: Serializable, const N: usize> Serializable for &Vec<[T; N]> {
-    fn write_into<W: ByteWriter>(&self, target: &mut W) {
-        let source = flatten_slice_elements(self);
-        T::write_batch_into(source, target);
-    }
-}
-
 impl<T: Serializable> Serializable for &[T] {
     fn write_into<W: ByteWriter>(&self, target: &mut W) {
         T::write_batch_into(self, target);
     }
 }
 
-impl<T: Serializable, const N: usize> Serializable for &[[T; N]] {
+impl<T: Serializable, const C: usize> Serializable for [T; C] {
     fn write_into<W: ByteWriter>(&self, target: &mut W) {
-        let source = flatten_slice_elements(self);
-        T::write_batch_into(source, target);
+        T::write_batch_into(self, target);
     }
 }
 
@@ -437,3 +422,17 @@ impl Deserializable for String {
         String::from_utf8(data).map_err(|err| DeserializationError::InvalidValue(format!("{err}")))
     }
 }
+
+impl<T: Deserializable, const C: usize> Deserializable for [T; C] {
+    fn read_from<R: ByteReader>(source: &mut R) -> Result<Self, DeserializationError> {
+        let data: Vec<T> = T::read_batch_from(source, C)?;
+
+        // SAFETY: the call above only returns a Vec if there are `C` elements, this conversion
+        // always succeeds
+        let res = data.try_into().unwrap_or_else(|v: Vec<T>| {
+            panic!("Expected a Vec of length {} but it was {}", C, v.len())
+        });
+
+        Ok(res)
+    }
+}