use core::fmt;
use core::marker::PhantomData;
use serde_::de::{Deserialize, Deserializer, SeqAccess, Visitor};
use serde_::ser::{Serialize, Serializer};
use crate::Vc;
mod helper {
use serde_::de::{Deserialize, DeserializeSeed, Deserializer};
#[inline]
pub(super) fn cautious_size_hint(hint: Option<usize>) -> usize {
core::cmp::min(hint.unwrap_or(0), 4096)
}
pub(super) struct InPlaceSeed<'a, T>(pub &'a mut T);
impl<'a, 'de, T> DeserializeSeed<'de> for InPlaceSeed<'a, T>
where
T: Deserialize<'de>,
{
type Value = ();
fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
where
D: Deserializer<'de>,
{
T::deserialize_in_place(deserializer, self.0)
}
}
}
impl<T> Serialize for Vc<T>
where
T: Serialize,
{
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.collect_seq(self)
}
}
impl<'de, T> Deserialize<'de> for Vc<T>
where
T: Deserialize<'de>,
{
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
struct VcVisitor<T> {
marker: PhantomData<T>,
}
impl<'de, T> Visitor<'de> for VcVisitor<T>
where
T: Deserialize<'de>,
{
type Value = Vc<T>;
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 = Vc::with_capacity(helper::cautious_size_hint(seq.size_hint()));
while let Some(value) = seq.next_element()? {
values.push(value);
}
Ok(values)
}
}
let visitor = VcVisitor {
marker: PhantomData,
};
deserializer.deserialize_seq(visitor)
}
fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error>
where
D: Deserializer<'de>,
{
struct VcInPlaceVisitor<'a, T>(&'a mut Vc<T>);
impl<'a, 'de, T> Visitor<'de> for VcInPlaceVisitor<'a, T>
where
T: Deserialize<'de>,
{
type Value = ();
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 hint = helper::cautious_size_hint(seq.size_hint());
if let Some(additional) = hint.checked_sub(self.0.len()) {
self.0.reserve(additional);
}
for i in 0..self.0.len() {
let next = {
let next_place = helper::InPlaceSeed(&mut self.0[i]);
seq.next_element_seed(next_place)?
};
if next.is_none() {
self.0.truncate(i);
return Ok(());
}
}
while let Some(value) = seq.next_element()? {
self.0.push(value);
}
Ok(())
}
}
deserializer.deserialize_seq(VcInPlaceVisitor(place))
}
}