use crate::error::{Error, Result};
use byteorder::{LittleEndian, ReadBytesExt};
use serde::de::IntoDeserializer;
pub struct Deserializer<'a> {
reader: &'a mut std::io::Read,
}
impl<'a> Deserializer<'a> {
pub fn new(reader: &'a mut std::io::Read) -> Self {
Self { reader }
}
fn read_signed(&mut self) -> Result<i64> {
leb128::read::signed(&mut self.reader).map_err(Into::into)
}
fn read_unsigned(&mut self) -> Result<u64> {
leb128::read::unsigned(&mut self.reader).map_err(Into::into)
}
fn read_vec(&mut self) -> Result<Vec<u8>> {
let len: usize = serde::Deserialize::deserialize(&mut *self)?;
let mut result = vec![0u8; len];
self.reader.read_exact(&mut result)?;
Ok(result)
}
fn read_string(&mut self) -> Result<String> {
let vec = self.read_vec()?;
String::from_utf8(vec).map_err(|e| Error::InvalidUtf8Encoding(e.utf8_error()))
}
}
macro_rules! impl_uint {
($ty:ty, $dser_method:ident, $visitor_method:ident, $reader_method:ident) => {
#[inline]
fn $dser_method<V>(self, visitor: V) -> Result<V::Value>
where V: serde::de::Visitor<'de>,
{
let value = self.$reader_method()?;
if value > <$ty>::max_value() as u64 {
Err(Error::NumberOutOfRange)
} else {
visitor.$visitor_method(value as $ty)
}
}
}
}
macro_rules! impl_int {
($ty:ty, $dser_method:ident, $visitor_method:ident, $reader_method:ident) => {
#[inline]
fn $dser_method<V>(self, visitor: V) -> Result<V::Value>
where V: serde::de::Visitor<'de>,
{
let value = self.$reader_method()?;
if value < <$ty>::min_value() as i64 || value > <$ty>::max_value() as i64 {
Err(Error::NumberOutOfRange)
} else {
visitor.$visitor_method(value as $ty)
}
}
}
}
macro_rules! impl_float {
($dser_method:ident, $visitor_method:ident, $reader_method:ident) => {
#[inline]
fn $dser_method<V>(self, visitor: V) -> Result<V::Value>
where V: serde::de::Visitor<'de>,
{
let value = self.reader.$reader_method::<LittleEndian>()?;
visitor.$visitor_method(value)
}
}
}
impl<'de, 'a, 'b> serde::Deserializer<'de> for &'a mut Deserializer<'b> {
type Error = Error;
#[inline]
fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_u8(self.reader.read_u8()?)
}
#[inline]
fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_i8(self.reader.read_i8()?)
}
impl_uint!(u16, deserialize_u16, visit_u16, read_unsigned);
impl_uint!(u32, deserialize_u32, visit_u32, read_unsigned);
impl_uint!(u64, deserialize_u64, visit_u64, read_unsigned);
impl_int!(i16, deserialize_i16, visit_i16, read_signed);
impl_int!(i32, deserialize_i32, visit_i32, read_signed);
impl_int!(i64, deserialize_i64, visit_i64, read_signed);
impl_float!(deserialize_f32, visit_f32, read_f32);
impl_float!(deserialize_f64, visit_f64, read_f64);
#[inline]
fn deserialize_any<V>(self, _visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
Err(Error::DeserializeAnyNotSupported)
}
fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
let value: u8 = serde::Deserialize::deserialize(self)?;
match value {
1 => visitor.visit_bool(true),
0 => visitor.visit_bool(false),
value => Err(Error::InvalidBoolEncoding(value).into()),
}
}
fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_unit()
}
fn deserialize_char<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
let value: u32 = serde::Deserialize::deserialize(self)?;
match std::char::from_u32(value) {
Some(c) => visitor.visit_char(c),
None => Err(Error::InvalidCharEncoding(value)),
}
}
fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_string(self.read_string()?)
}
fn deserialize_string<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_string(self.read_string()?)
}
fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_byte_buf(self.read_vec()?)
}
fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_byte_buf(self.read_vec()?)
}
fn deserialize_enum<V>(
self,
_enum: &'static str,
_variants: &'static [&'static str],
visitor: V,
) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_enum(self)
}
fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_seq(Access {
deserializer: self,
len,
})
}
fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
let value: u8 = serde::de::Deserialize::deserialize(&mut *self)?;
match value {
0 => visitor.visit_none(),
1 => visitor.visit_some(&mut *self),
v => Err(Error::InvalidTagEncoding(v as usize)),
}
}
fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
let len = serde::Deserialize::deserialize(&mut *self)?;
self.deserialize_tuple(len, visitor)
}
fn deserialize_map<V>(self, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
let len = serde::Deserialize::deserialize(&mut *self)?;
visitor.visit_map(Access {
deserializer: self,
len,
})
}
fn deserialize_struct<V>(
self,
_name: &str,
fields: &'static [&'static str],
visitor: V,
) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
self.deserialize_tuple(fields.len(), visitor)
}
fn deserialize_identifier<V>(self, _visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
Err(Error::DeserializeIdentifierNotSupported)
}
fn deserialize_newtype_struct<V>(self, _name: &str, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_newtype_struct(self)
}
fn deserialize_unit_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
visitor.visit_unit()
}
fn deserialize_tuple_struct<V>(
self,
_name: &'static str,
len: usize,
visitor: V,
) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
self.deserialize_tuple(len, visitor)
}
fn deserialize_ignored_any<V>(self, _visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
Err(Error::DeserializeIgnoredAnyNotSupported)
}
fn is_human_readable(&self) -> bool {
false
}
}
struct Access<'a, 'b> {
deserializer: &'a mut Deserializer<'b>,
len: usize,
}
impl<'de, 'a, 'b> serde::de::SeqAccess<'de> for Access<'a, 'b> {
type Error = Error;
fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
where
T: serde::de::DeserializeSeed<'de>,
{
if self.len > 0 {
self.len -= 1;
let value = serde::de::DeserializeSeed::deserialize(seed, &mut *self.deserializer)?;
Ok(Some(value))
} else {
Ok(None)
}
}
fn size_hint(&self) -> Option<usize> {
Some(self.len)
}
}
impl<'de, 'a, 'b> serde::de::MapAccess<'de> for Access<'a, 'b> {
type Error = Error;
fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
where
K: serde::de::DeserializeSeed<'de>,
{
if self.len > 0 {
self.len -= 1;
let key = serde::de::DeserializeSeed::deserialize(seed, &mut *self.deserializer)?;
Ok(Some(key))
} else {
Ok(None)
}
}
fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value>
where
V: serde::de::DeserializeSeed<'de>,
{
let value = serde::de::DeserializeSeed::deserialize(seed, &mut *self.deserializer)?;
Ok(value)
}
fn size_hint(&self) -> Option<usize> {
Some(self.len)
}
}
impl<'de, 'a, 'b> serde::de::EnumAccess<'de> for &'a mut Deserializer<'b> {
type Error = Error;
type Variant = Self;
fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant)>
where
V: serde::de::DeserializeSeed<'de>,
{
let idx: u32 = serde::de::Deserialize::deserialize(&mut *self)?;
let val: Result<_> = seed.deserialize(idx.into_deserializer());
Ok((val?, self))
}
}
impl<'de, 'a, 'b> serde::de::VariantAccess<'de> for &'a mut Deserializer<'b> {
type Error = Error;
fn unit_variant(self) -> Result<()> {
Ok(())
}
fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value>
where
T: serde::de::DeserializeSeed<'de>,
{
serde::de::DeserializeSeed::deserialize(seed, self)
}
fn tuple_variant<V>(self, len: usize, visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
serde::de::Deserializer::deserialize_tuple(self, len, visitor)
}
fn struct_variant<V>(self, fields: &'static [&'static str], visitor: V) -> Result<V::Value>
where
V: serde::de::Visitor<'de>,
{
serde::de::Deserializer::deserialize_tuple(self, fields.len(), visitor)
}
}