From b6869995e712a5a75f35cc8838344f1cb6637c3a Mon Sep 17 00:00:00 2001
From: Nikita Rushmanov <nikita.rushmanov@woven-planet.global>
Date: Tue, 28 May 2024 09:48:04 -0700
Subject: [PATCH] Serde implementations on HistoryBuffer

---
 src/de.rs  | 41 +++++++++++++++++++++++++++++++++++++++--
 src/ser.rs | 18 +++++++++++++++++-
 2 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/src/de.rs b/src/de.rs
index 96052273..455295b7 100644
--- a/src/de.rs
+++ b/src/de.rs
@@ -1,6 +1,6 @@
 use crate::{
-    binary_heap::Kind as BinaryHeapKind, BinaryHeap, Deque, IndexMap, IndexSet, LinearMap, String,
-    Vec,
+    binary_heap::Kind as BinaryHeapKind, BinaryHeap, Deque, HistoryBuffer, IndexMap, IndexSet,
+    LinearMap, String, Vec,
 };
 use core::{
     fmt,
@@ -173,6 +173,43 @@ where
     }
 }
 
+impl<'de, T, const N: usize> Deserialize<'de> for HistoryBuffer<T, N>
+where
+    T: Deserialize<'de>,
+{
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct ValueVisitor<'de, T, const N: usize>(PhantomData<(&'de (), T)>);
+
+        impl<'de, T, const N: usize> serde::de::Visitor<'de> for ValueVisitor<'de, T, N>
+        where
+            T: Deserialize<'de>,
+        {
+            type Value = HistoryBuffer<T, N>;
+
+            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+                formatter.write_str("a sequence")
+            }
+
+            fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+            where
+                A: SeqAccess<'de>,
+            {
+                let mut values = HistoryBuffer::new();
+
+                while let Some(value) = seq.next_element()? {
+                    values.write(value);
+                }
+
+                Ok(values)
+            }
+        }
+        deserializer.deserialize_seq(ValueVisitor(PhantomData))
+    }
+}
+
 // Dictionaries
 
 impl<'de, K, V, S, const N: usize> Deserialize<'de> for IndexMap<K, V, BuildHasherDefault<S>, N>
diff --git a/src/ser.rs b/src/ser.rs
index 05231319..9839da2a 100644
--- a/src/ser.rs
+++ b/src/ser.rs
@@ -2,7 +2,7 @@ use core::hash::{BuildHasher, Hash};
 
 use crate::{
     binary_heap::Kind as BinaryHeapKind, storage::Storage, vec::VecInner, BinaryHeap, Deque,
-    IndexMap, IndexSet, LinearMap, String,
+    HistoryBuffer, IndexMap, IndexSet, LinearMap, String,
 };
 use serde::ser::{Serialize, SerializeMap, SerializeSeq, Serializer};
 
@@ -74,6 +74,22 @@ where
     }
 }
 
+impl<T, const N: usize> Serialize for HistoryBuffer<T, N>
+where
+    T: Serialize,
+{
+    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.oldest_ordered() {
+            seq.serialize_element(element)?;
+        }
+        seq.end()
+    }
+}
+
 // Dictionaries
 
 impl<K, V, S, const N: usize> Serialize for IndexMap<K, V, S, N>