use ducc::{Elements, Properties, Value};
use error::{Error, Result};
use serde;
use serde::de::IntoDeserializer;
pub struct Deserializer<'ducc> {
pub value: Value<'ducc>,
}
impl<'ducc, 'de> serde::Deserializer<'de> for Deserializer<'ducc> {
type Error = Error;
#[inline]
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>
{
match self.value {
Value::Undefined => visitor.visit_unit(),
Value::Null => visitor.visit_none(),
Value::Boolean(v) => visitor.visit_bool(v),
Value::Number(v) => visitor.visit_f64(v),
Value::String(v) => visitor.visit_str(&v.to_string()?),
Value::Array(v) => {
let len = v.len()?;
let mut deserializer = SeqDeserializer(v.elements());
let seq = visitor.visit_seq(&mut deserializer)?;
let remaining = deserializer.0.count();
if remaining == 0 {
Ok(seq)
} else {
Err(serde::de::Error::invalid_length(len, &"fewer elements in array"))
}
},
Value::Object(v) => {
let len = v.len()? as usize;
let mut deserializer = MapDeserializer(v.properties(), None);
let map = visitor.visit_map(&mut deserializer)?;
let remaining = deserializer.0.count();
if remaining == 0 {
Ok(map)
} else {
Err(serde::de::Error::invalid_length(len, &"fewer elements in array"))
}
},
Value::Bytes(v) => visitor.visit_bytes(&v.to_vec()),
_ => visitor.visit_unit(),
}
}
#[inline]
fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>
{
match self.value {
Value::Null | Value::Undefined => visitor.visit_none(),
_ => visitor.visit_some(self),
}
}
#[inline]
fn deserialize_enum<V>(
self,
_name: &str,
_variants: &'static [&'static str],
visitor: V,
) -> Result<V::Value>
where
V: serde::de::Visitor<'de>
{
let (variant, value) = match self.value {
Value::Object(value) => {
let mut iter = value.properties::<String, Value>();
let (variant, value) = match iter.next() {
Some(v) => v?,
None => return Err(serde::de::Error::invalid_value(
serde::de::Unexpected::Map,
&"map with a single key",
)),
};
if iter.next().is_some() {
return Err(serde::de::Error::invalid_value(
serde::de::Unexpected::Map,
&"map with a single key",
))
}
(variant, Some(value))
}
Value::String(variant) => (variant.to_string()?, None),
_ => return Err(serde::de::Error::custom("bad enum value")),
};
visitor.visit_enum(EnumDeserializer { variant, value })
}
forward_to_deserialize_any! {
bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
byte_buf unit unit_struct newtype_struct seq tuple
tuple_struct map struct identifier ignored_any
}
}
struct SeqDeserializer<'ducc>(Elements<'ducc, Value<'ducc>>);
impl<'ducc, 'de> serde::de::SeqAccess<'de> for SeqDeserializer<'ducc> {
type Error = Error;
fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
where
T: serde::de::DeserializeSeed<'de>
{
match self.0.next() {
Some(value) => seed.deserialize(Deserializer { value: value? }).map(Some),
None => Ok(None),
}
}
fn size_hint(&self) -> Option<usize> {
match self.0.size_hint() {
(lower, Some(upper)) if lower == upper => Some(upper),
_ => None,
}
}
}
struct MapDeserializer<'ducc>(
Properties<'ducc, Value<'ducc>, Value<'ducc>>,
Option<Value<'ducc>>
);
impl<'ducc, 'de> serde::de::MapAccess<'de> for MapDeserializer<'ducc> {
type Error = Error;
fn next_key_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
where
T: serde::de::DeserializeSeed<'de>
{
loop {
match self.0.next() {
Some(item) => {
let (key, value) = item?;
match value {
Value::Null => { },
Value::Boolean(ref _v) => { },
Value::Number(ref _v) => { },
Value::String(ref _v) => { },
Value::Array(ref _v) => { },
Value::Object(ref _v) => { },
Value::Bytes(ref _v) => { },
_ => continue,
}
self.1 = Some(value);
let key_de = Deserializer { value: key };
return seed.deserialize(key_de).map(Some);
},
None => return Ok(None),
}
}
}
fn next_value_seed<T>(&mut self, seed: T) -> Result<T::Value>
where
T: serde::de::DeserializeSeed<'de>
{
match self.1.take() {
Some(value) => seed.deserialize(Deserializer { value }),
None => Err(serde::de::Error::custom("value is missing")),
}
}
fn size_hint(&self) -> Option<usize> {
match self.0.size_hint() {
(lower, Some(upper)) if lower == upper => Some(upper),
_ => None,
}
}
}
struct EnumDeserializer<'ducc> {
variant: String,
value: Option<Value<'ducc>>,
}
impl<'ducc, 'de> serde::de::EnumAccess<'de> for EnumDeserializer<'ducc> {
type Error = Error;
type Variant = VariantDeserializer<'ducc>;
fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant)>
where
T: serde::de::DeserializeSeed<'de>
{
let variant = self.variant.into_deserializer();
let variant_access = VariantDeserializer { value: self.value };
seed.deserialize(variant).map(|v| (v, variant_access))
}
}
struct VariantDeserializer<'ducc> {
value: Option<Value<'ducc>>,
}
impl<'ducc, 'de> serde::de::VariantAccess<'de> for VariantDeserializer<'ducc> {
type Error = Error;
fn unit_variant(self) -> Result<()> {
match self.value {
Some(_) => Err(serde::de::Error::invalid_type(
serde::de::Unexpected::NewtypeVariant,
&"unit variant",
)),
None => Ok(())
}
}
fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value>
where
T: serde::de::DeserializeSeed<'de>
{
match self.value {
Some(value) => seed.deserialize(Deserializer { value }),
None => Err(serde::de::Error::invalid_type(
serde::de::Unexpected::UnitVariant,
&"newtype variant",
))
}
}
fn tuple_variant<V>(self, _len: usize, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>
{
match self.value {
Some(value) => serde::Deserializer::deserialize_seq(
Deserializer { value },
visitor,
),
None => Err(serde::de::Error::invalid_type(
serde::de::Unexpected::UnitVariant,
&"tuple variant",
))
}
}
fn struct_variant<V>(
self, _fields: &'static [&'static str], visitor: V
) -> Result<V::Value>
where V: serde::de::Visitor<'de>
{
match self.value {
Some(value) => serde::Deserializer::deserialize_map(
Deserializer { value },
visitor,
),
None => Err(serde::de::Error::invalid_type(
serde::de::Unexpected::UnitVariant,
&"struct variant",
))
}
}
}