// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
// (online at:
https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
use super::LiteMap;
use crate::store::*;
use core::fmt;
use core::marker::PhantomData;
use serde::de::{MapAccess, SeqAccess, Visitor};
use serde::{Deserialize, Deserializer};
#[cfg(feature = "serde")]
use serde::{ser::SerializeMap, Serialize, Serializer};
#[cfg(feature = "serde")]
impl<K, V, R> Serialize for LiteMap<K, V, R>
where
K: Serialize,
V: Serialize,
R: Store<K, V> + Serialize,
{
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
// Many human-readable formats don't support values other
// than numbers and strings as map keys. For them, we can serialize
// as a vec of tuples instead
if serializer.is_human_readable() {
if let Some((ref k, _)) = self.values.lm_get(0) {
if !super::serde_helpers::is_num_or_string(k) {
return self.values.serialize(serializer);
}
// continue to regular serialization
}
}
let mut map = serializer.serialize_map(Some(self.len()))?;
let mut i = 0;
while i < self.values.lm_len() {
#[allow(clippy::unwrap_used)] // i is in range
let (k, v) = self.values.lm_get(i).unwrap();
map.serialize_entry(k, v)?;
i += 1;
}
map.end()
}
}
/// Modified example from
https://serde.rs/deserialize-map.html
#[allow(clippy::type_complexity)]
struct LiteMapVisitor<K, V, R> {
marker: PhantomData<fn() -> LiteMap<K, V, R>>,
}
impl<K, V, R> LiteMapVisitor<K, V, R> {
fn new() -> Self {
Self {
marker: PhantomData,
}
}
}
impl<'de, K, V, R> Visitor<'de> for LiteMapVisitor<K, V, R>
where
K: Deserialize<'de> + Ord,
V: Deserialize<'de>,
R: StoreMut<K, V> + StoreFromIterable<K, V>,
{
type Value = LiteMap<K, V, R>;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a map produced by LiteMap")
}
fn visit_seq<S>(self, mut access: S) -> Result<Self::Value, S::Error>
where
S: SeqAccess<'de>,
{
let mut map = LiteMap::with_capacity(access.size_hint().unwrap_or(0));
// While there are entries remaining in the input, add them
// into our map.
while let Some((key, value)) = access.next_element()? {
// Try to append it at the end, hoping for a sorted map.
// If not sorted, insert as usual.
// This allows for arbitrary maps (e.g. from user JSON)
// to be deserialized into LiteMap
// without impacting performance in the case of deserializing
// a serialized map that came from another LiteMap
if let Some((key, value)) = map.try_append(key, value) {
// Note: this effectively selection sorts the map,
// which isn't efficient for large maps
map.insert(key, value);
}
}
Ok(map)
}
fn visit_map<M>(self, mut access: M) -> Result<Self::Value, M::Error>
where
M: MapAccess<'de>,
{
let mut map = LiteMap::with_capacity(access.size_hint().unwrap_or(0));
// While there are entries remaining in the input, add them
// into our map.
while let Some((key, value)) = access.next_entry()? {
// Try to append it at the end, hoping for a sorted map.
// If not sorted, insert as usual.
// This allows for arbitrary maps (e.g. from user JSON)
// to be deserialized into LiteMap
// without impacting performance in the case of deserializing
// a serialized map that came from another LiteMap
if let Some((key, value)) = map.try_append(key, value) {
// Note: this effectively selection sorts the map,
// which isn't efficient for large maps
map.insert(key, value);
}
}
Ok(map)
}
}
impl<'de, K, V, R> Deserialize<'de> for LiteMap<K, V, R>
where
K: Ord + Deserialize<'de>,
V: Deserialize<'de>,
R: StoreMut<K, V> + StoreFromIterable<K, V>,
{
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
if deserializer.is_human_readable() {
// deserialize_any only works on self-describing (human-readable)
// formats
deserializer.deserialize_any(LiteMapVisitor::new())
} else {
deserializer.deserialize_map(LiteMapVisitor::new())
}
}
}
#[cfg(test)]
mod test {
use crate::LiteMap;
use alloc::borrow::ToOwned;
use alloc::string::String;
fn get_simple_map() -> LiteMap<u32, String> {
[
(1, "one".to_owned()),
(2, "two".to_owned()),
(4, "four".to_owned()),
(5, "five".to_owned()),
]
.into_iter()
.collect()
}
fn get_tuple_map() -> LiteMap<(u32, String), String> {
[
((1, "en".to_owned()), "one".to_owned()),
((1, "zh".to_owned()), "一".to_owned()),
((2, "en".to_owned()), "two".to_owned()),
((2, "zh".to_owned()), "二".to_owned()),
((4, "en".to_owned()), "four".to_owned()),
((5, "en".to_owned()), "five".to_owned()),
((5, "zh".to_owned()), "五".to_owned()),
((7, "zh".to_owned()), "七".to_owned()),
]
.into_iter()
.collect()
}
#[test]
fn test_roundtrip_json() {
let map = get_simple_map();
let json = serde_json::to_string(&map).unwrap();
assert_eq!(
json,
"{\"1\":\"one\",\"2\":\"two\",\"4\":\"four\",\"5\":\"five\"}"
);
let deserialized: LiteMap<u32, String> = serde_json::from_str(&json).unwrap();
assert_eq!(map, deserialized);
let map = get_tuple_map();
let json = serde_json::to_string(&map).unwrap();
assert_eq!(
json,
"[[[1,\"en\"],\"one\"],[[1,\"zh\"],\"一\"],[[2,\"en\"],\"two\"],\
[[2,\"zh\"],\"二\"],[[4,\"en\"],\"four\"],[[5,\"en\"],\"five\"],\
[[5,\"zh\"],\"五\"],[[7,\"zh\"],\"七\"]]"
);
let deserialized: LiteMap<(u32, String), String> = serde_json::from_str(&json).unwrap();
assert_eq!(map, deserialized);
}
#[test]
fn test_roundtrip_postcard() {
let map = get_simple_map();
let postcard = postcard::to_stdvec(&map).unwrap();
let deserialized: LiteMap<u32, String> = postcard::from_bytes(&postcard).unwrap();
assert_eq!(map, deserialized);
let map = get_tuple_map();
let postcard = postcard::to_stdvec(&map).unwrap();
let deserialized: LiteMap<(u32, String), String> = postcard::from_bytes(&postcard).unwrap();
assert_eq!(map, deserialized);
}
}
