use serde::de;
use std::fmt::Display;
use std::fs::File;
use std::io::{BufReader, Read, Seek};
use std::iter::Peekable;
use std::path::Path;
use stream::{self, Event};
use {u64_to_usize, Error};
macro_rules! expect {
($next:expr, $pat:pat) => {
match $next {
Some(Ok(v @ $pat)) => v,
None => return Err(Error::UnexpectedEof),
_ => return Err(event_mismatch_error()),
}
};
($next:expr, $pat:pat => $save:expr) => {
match $next {
Some(Ok($pat)) => $save,
None => return Err(Error::UnexpectedEof),
_ => return Err(event_mismatch_error()),
}
};
}
macro_rules! try_next {
($next:expr) => {
match $next {
Some(Ok(v)) => v,
Some(Err(_)) => return Err(event_mismatch_error()),
None => return Err(Error::UnexpectedEof),
}
};
}
fn event_mismatch_error() -> Error {
Error::InvalidData
}
impl de::Error for Error {
fn custom<T: Display>(msg: T) -> Self {
Error::Serde(msg.to_string())
}
}
pub struct Deserializer<I>
where
I: IntoIterator<Item = Result<Event, Error>>,
{
events: Peekable<<I as IntoIterator>::IntoIter>,
}
impl<I> Deserializer<I>
where
I: IntoIterator<Item = Result<Event, Error>>,
{
pub fn new(iter: I) -> Deserializer<I> {
Deserializer {
events: iter.into_iter().peekable(),
}
}
}
impl<'de, 'a, I> de::Deserializer<'de> for &'a mut Deserializer<I>
where
I: IntoIterator<Item = Result<Event, Error>>,
{
type Error = Error;
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
match try_next!(self.events.next()) {
Event::StartArray(len) => {
let len = len.and_then(u64_to_usize);
let ret = visitor.visit_seq(MapAndSeqAccess::new(self, false, len))?;
expect!(self.events.next(), Event::EndArray);
Ok(ret)
}
Event::EndArray => Err(event_mismatch_error()),
Event::StartDictionary(len) => {
let len = len.and_then(u64_to_usize);
let ret = visitor.visit_map(MapAndSeqAccess::new(self, false, len))?;
expect!(self.events.next(), Event::EndDictionary);
Ok(ret)
}
Event::EndDictionary => Err(event_mismatch_error()),
Event::BooleanValue(v) => visitor.visit_bool(v),
Event::DataValue(v) => visitor.visit_byte_buf(v),
Event::DateValue(v) => visitor.visit_string(v.to_rfc3339()),
Event::IntegerValue(v) if v.is_positive() => visitor.visit_u64(v as u64),
Event::IntegerValue(v) => visitor.visit_i64(v as i64),
Event::RealValue(v) => visitor.visit_f64(v),
Event::StringValue(v) => visitor.visit_string(v),
}
}
forward_to_deserialize_any! {
bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string
seq bytes byte_buf map unit_struct
tuple_struct tuple ignored_any identifier
}
fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
expect!(self.events.next(), Event::StringValue(_));
visitor.visit_unit()
}
fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
expect!(self.events.next(), Event::StartDictionary(_));
let ret = match try_next!(self.events.next()) {
Event::StringValue(ref s) if &s[..] == "None" => {
expect!(self.events.next(), Event::StringValue(_));
visitor.visit_none::<Self::Error>()?
}
Event::StringValue(ref s) if &s[..] == "Some" => visitor.visit_some(&mut *self)?,
_ => return Err(event_mismatch_error()),
};
expect!(self.events.next(), Event::EndDictionary);
Ok(ret)
}
fn deserialize_newtype_struct<V>(
self,
_name: &'static str,
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
visitor.visit_newtype_struct(self)
}
fn deserialize_struct<V>(
self,
_name: &'static str,
_fields: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
expect!(self.events.next(), Event::StartDictionary(_));
let ret = visitor.visit_map(MapAndSeqAccess::new(self, true, None))?;
expect!(self.events.next(), Event::EndDictionary);
Ok(ret)
}
fn deserialize_enum<V>(
self,
_enum: &'static str,
_variants: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
expect!(self.events.next(), Event::StartDictionary(_));
let ret = visitor.visit_enum(&mut *self)?;
expect!(self.events.next(), Event::EndDictionary);
Ok(ret)
}
}
impl<'de, 'a, I> de::EnumAccess<'de> for &'a mut Deserializer<I>
where
I: IntoIterator<Item = Result<Event, Error>>,
{
type Error = Error;
type Variant = Self;
fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self), Self::Error>
where
V: de::DeserializeSeed<'de>,
{
Ok((seed.deserialize(&mut *self)?, self))
}
}
impl<'de, 'a, I> de::VariantAccess<'de> for &'a mut Deserializer<I>
where
I: IntoIterator<Item = Result<Event, Error>>,
{
type Error = Error;
fn unit_variant(self) -> Result<(), Self::Error> {
<() as de::Deserialize>::deserialize(self)
}
fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Self::Error>
where
T: de::DeserializeSeed<'de>,
{
seed.deserialize(self)
}
fn tuple_variant<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
<Self as de::Deserializer>::deserialize_tuple(self, len, visitor)
}
fn struct_variant<V>(
self,
fields: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
let name = "";
<Self as de::Deserializer>::deserialize_struct(self, name, fields, visitor)
}
}
pub struct StructValueDeserializer<'a, I: 'a>
where
I: IntoIterator<Item = Result<Event, Error>>,
{
de: &'a mut Deserializer<I>,
}
impl<'de, 'a, I> de::Deserializer<'de> for StructValueDeserializer<'a, I>
where
I: IntoIterator<Item = Result<Event, Error>>,
{
type Error = Error;
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
self.de.deserialize_any(visitor)
}
forward_to_deserialize_any! {
bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string
seq bytes byte_buf map unit_struct
tuple_struct tuple ignored_any identifier
}
fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
self.de.deserialize_unit(visitor)
}
fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
visitor.visit_some(self.de)
}
fn deserialize_newtype_struct<V>(
self,
name: &'static str,
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
self.de.deserialize_newtype_struct(name, visitor)
}
fn deserialize_struct<V>(
self,
name: &'static str,
fields: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
self.de.deserialize_struct(name, fields, visitor)
}
fn deserialize_enum<V>(
self,
enum_: &'static str,
variants: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
self.de.deserialize_enum(enum_, variants, visitor)
}
}
struct MapAndSeqAccess<'a, I>
where
I: 'a + IntoIterator<Item = Result<Event, Error>>,
{
de: &'a mut Deserializer<I>,
is_struct: bool,
remaining: Option<usize>,
}
impl<'a, I> MapAndSeqAccess<'a, I>
where
I: 'a + IntoIterator<Item = Result<Event, Error>>,
{
fn new(
de: &'a mut Deserializer<I>,
is_struct: bool,
len: Option<usize>,
) -> MapAndSeqAccess<'a, I> {
MapAndSeqAccess {
de,
is_struct,
remaining: len,
}
}
}
impl<'de, 'a, I> de::SeqAccess<'de> for MapAndSeqAccess<'a, I>
where
I: 'a + IntoIterator<Item = Result<Event, Error>>,
{
type Error = Error;
fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error>
where
T: de::DeserializeSeed<'de>,
{
if let Some(&Ok(Event::EndArray)) = self.de.events.peek() {
return Ok(None);
}
self.remaining = self.remaining.map(|r| r.saturating_sub(1));
seed.deserialize(&mut *self.de).map(Some)
}
fn size_hint(&self) -> Option<usize> {
self.remaining
}
}
impl<'de, 'a, I> de::MapAccess<'de> for MapAndSeqAccess<'a, I>
where
I: 'a + IntoIterator<Item = Result<Event, Error>>,
{
type Error = Error;
fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Self::Error>
where
K: de::DeserializeSeed<'de>,
{
if let Some(&Ok(Event::EndDictionary)) = self.de.events.peek() {
return Ok(None);
}
self.remaining = self.remaining.map(|r| r.saturating_sub(1));
seed.deserialize(&mut *self.de).map(Some)
}
fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error>
where
V: de::DeserializeSeed<'de>,
{
if self.is_struct {
seed.deserialize(StructValueDeserializer { de: &mut *self.de })
} else {
seed.deserialize(&mut *self.de)
}
}
fn size_hint(&self) -> Option<usize> {
self.remaining
}
}
pub fn from_file<P: AsRef<Path>, T: de::DeserializeOwned>(path: P) -> Result<T, Error> {
let file = File::open(path)?;
from_reader(BufReader::new(file))
}
pub fn from_reader<R: Read + Seek, T: de::DeserializeOwned>(reader: R) -> Result<T, Error> {
let reader = stream::Reader::new(reader);
let mut de = Deserializer::new(reader);
de::Deserialize::deserialize(&mut de)
}
pub fn from_reader_xml<R: Read, T: de::DeserializeOwned>(reader: R) -> Result<T, Error> {
let reader = stream::XmlReader::new(reader);
let mut de = Deserializer::new(reader);
de::Deserialize::deserialize(&mut de)
}