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-rw-r--r--third_party/rust/serde_json/src/de.rs2606
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diff --git a/third_party/rust/serde_json/src/de.rs b/third_party/rust/serde_json/src/de.rs
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+//! Deserialize JSON data to a Rust data structure.
+
+use crate::error::{Error, ErrorCode, Result};
+#[cfg(feature = "float_roundtrip")]
+use crate::lexical;
+use crate::number::Number;
+use crate::read::{self, Fused, Reference};
+use alloc::string::String;
+use alloc::vec::Vec;
+#[cfg(feature = "float_roundtrip")]
+use core::iter;
+use core::iter::FusedIterator;
+use core::marker::PhantomData;
+use core::result;
+use core::str::FromStr;
+use serde::de::{self, Expected, Unexpected};
+use serde::forward_to_deserialize_any;
+
+#[cfg(feature = "arbitrary_precision")]
+use crate::number::NumberDeserializer;
+
+pub use crate::read::{Read, SliceRead, StrRead};
+
+#[cfg(feature = "std")]
+pub use crate::read::IoRead;
+
+//////////////////////////////////////////////////////////////////////////////
+
+/// A structure that deserializes JSON into Rust values.
+pub struct Deserializer<R> {
+ read: R,
+ scratch: Vec<u8>,
+ remaining_depth: u8,
+ #[cfg(feature = "float_roundtrip")]
+ single_precision: bool,
+ #[cfg(feature = "unbounded_depth")]
+ disable_recursion_limit: bool,
+}
+
+impl<'de, R> Deserializer<R>
+where
+ R: read::Read<'de>,
+{
+ /// Create a JSON deserializer from one of the possible serde_json input
+ /// sources.
+ ///
+ /// Typically it is more convenient to use one of these methods instead:
+ ///
+ /// - Deserializer::from_str
+ /// - Deserializer::from_slice
+ /// - Deserializer::from_reader
+ pub fn new(read: R) -> Self {
+ Deserializer {
+ read,
+ scratch: Vec::new(),
+ remaining_depth: 128,
+ #[cfg(feature = "float_roundtrip")]
+ single_precision: false,
+ #[cfg(feature = "unbounded_depth")]
+ disable_recursion_limit: false,
+ }
+ }
+}
+
+#[cfg(feature = "std")]
+impl<R> Deserializer<read::IoRead<R>>
+where
+ R: crate::io::Read,
+{
+ /// Creates a JSON deserializer from an `io::Read`.
+ ///
+ /// Reader-based deserializers do not support deserializing borrowed types
+ /// like `&str`, since the `std::io::Read` trait has no non-copying methods
+ /// -- everything it does involves copying bytes out of the data source.
+ pub fn from_reader(reader: R) -> Self {
+ Deserializer::new(read::IoRead::new(reader))
+ }
+}
+
+impl<'a> Deserializer<read::SliceRead<'a>> {
+ /// Creates a JSON deserializer from a `&[u8]`.
+ pub fn from_slice(bytes: &'a [u8]) -> Self {
+ Deserializer::new(read::SliceRead::new(bytes))
+ }
+}
+
+impl<'a> Deserializer<read::StrRead<'a>> {
+ /// Creates a JSON deserializer from a `&str`.
+ pub fn from_str(s: &'a str) -> Self {
+ Deserializer::new(read::StrRead::new(s))
+ }
+}
+
+macro_rules! overflow {
+ ($a:ident * 10 + $b:ident, $c:expr) => {
+ match $c {
+ c => $a >= c / 10 && ($a > c / 10 || $b > c % 10),
+ }
+ };
+}
+
+pub(crate) enum ParserNumber {
+ F64(f64),
+ U64(u64),
+ I64(i64),
+ #[cfg(feature = "arbitrary_precision")]
+ String(String),
+}
+
+impl ParserNumber {
+ fn visit<'de, V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ match self {
+ ParserNumber::F64(x) => visitor.visit_f64(x),
+ ParserNumber::U64(x) => visitor.visit_u64(x),
+ ParserNumber::I64(x) => visitor.visit_i64(x),
+ #[cfg(feature = "arbitrary_precision")]
+ ParserNumber::String(x) => visitor.visit_map(NumberDeserializer { number: x.into() }),
+ }
+ }
+
+ fn invalid_type(self, exp: &dyn Expected) -> Error {
+ match self {
+ ParserNumber::F64(x) => de::Error::invalid_type(Unexpected::Float(x), exp),
+ ParserNumber::U64(x) => de::Error::invalid_type(Unexpected::Unsigned(x), exp),
+ ParserNumber::I64(x) => de::Error::invalid_type(Unexpected::Signed(x), exp),
+ #[cfg(feature = "arbitrary_precision")]
+ ParserNumber::String(_) => de::Error::invalid_type(Unexpected::Other("number"), exp),
+ }
+ }
+}
+
+impl<'de, R: Read<'de>> Deserializer<R> {
+ /// The `Deserializer::end` method should be called after a value has been fully deserialized.
+ /// This allows the `Deserializer` to validate that the input stream is at the end or that it
+ /// only has trailing whitespace.
+ pub fn end(&mut self) -> Result<()> {
+ match tri!(self.parse_whitespace()) {
+ Some(_) => Err(self.peek_error(ErrorCode::TrailingCharacters)),
+ None => Ok(()),
+ }
+ }
+
+ /// Turn a JSON deserializer into an iterator over values of type T.
+ pub fn into_iter<T>(self) -> StreamDeserializer<'de, R, T>
+ where
+ T: de::Deserialize<'de>,
+ {
+ // This cannot be an implementation of std::iter::IntoIterator because
+ // we need the caller to choose what T is.
+ let offset = self.read.byte_offset();
+ StreamDeserializer {
+ de: self,
+ offset,
+ failed: false,
+ output: PhantomData,
+ lifetime: PhantomData,
+ }
+ }
+
+ /// Parse arbitrarily deep JSON structures without any consideration for
+ /// overflowing the stack.
+ ///
+ /// You will want to provide some other way to protect against stack
+ /// overflows, such as by wrapping your Deserializer in the dynamically
+ /// growing stack adapter provided by the serde_stacker crate. Additionally
+ /// you will need to be careful around other recursive operations on the
+ /// parsed result which may overflow the stack after deserialization has
+ /// completed, including, but not limited to, Display and Debug and Drop
+ /// impls.
+ ///
+ /// *This method is only available if serde_json is built with the
+ /// `"unbounded_depth"` feature.*
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use serde::Deserialize;
+ /// use serde_json::Value;
+ ///
+ /// fn main() {
+ /// let mut json = String::new();
+ /// for _ in 0..10000 {
+ /// json = format!("[{}]", json);
+ /// }
+ ///
+ /// let mut deserializer = serde_json::Deserializer::from_str(&json);
+ /// deserializer.disable_recursion_limit();
+ /// let deserializer = serde_stacker::Deserializer::new(&mut deserializer);
+ /// let value = Value::deserialize(deserializer).unwrap();
+ ///
+ /// carefully_drop_nested_arrays(value);
+ /// }
+ ///
+ /// fn carefully_drop_nested_arrays(value: Value) {
+ /// let mut stack = vec![value];
+ /// while let Some(value) = stack.pop() {
+ /// if let Value::Array(array) = value {
+ /// stack.extend(array);
+ /// }
+ /// }
+ /// }
+ /// ```
+ #[cfg(feature = "unbounded_depth")]
+ #[cfg_attr(docsrs, doc(cfg(feature = "unbounded_depth")))]
+ pub fn disable_recursion_limit(&mut self) {
+ self.disable_recursion_limit = true;
+ }
+
+ fn peek(&mut self) -> Result<Option<u8>> {
+ self.read.peek()
+ }
+
+ fn peek_or_null(&mut self) -> Result<u8> {
+ Ok(tri!(self.peek()).unwrap_or(b'\x00'))
+ }
+
+ fn eat_char(&mut self) {
+ self.read.discard();
+ }
+
+ fn next_char(&mut self) -> Result<Option<u8>> {
+ self.read.next()
+ }
+
+ fn next_char_or_null(&mut self) -> Result<u8> {
+ Ok(tri!(self.next_char()).unwrap_or(b'\x00'))
+ }
+
+ /// Error caused by a byte from next_char().
+ #[cold]
+ fn error(&self, reason: ErrorCode) -> Error {
+ let position = self.read.position();
+ Error::syntax(reason, position.line, position.column)
+ }
+
+ /// Error caused by a byte from peek().
+ #[cold]
+ fn peek_error(&self, reason: ErrorCode) -> Error {
+ let position = self.read.peek_position();
+ Error::syntax(reason, position.line, position.column)
+ }
+
+ /// Returns the first non-whitespace byte without consuming it, or `None` if
+ /// EOF is encountered.
+ fn parse_whitespace(&mut self) -> Result<Option<u8>> {
+ loop {
+ match tri!(self.peek()) {
+ Some(b' ') | Some(b'\n') | Some(b'\t') | Some(b'\r') => {
+ self.eat_char();
+ }
+ other => {
+ return Ok(other);
+ }
+ }
+ }
+ }
+
+ #[cold]
+ fn peek_invalid_type(&mut self, exp: &dyn Expected) -> Error {
+ let err = match self.peek_or_null().unwrap_or(b'\x00') {
+ b'n' => {
+ self.eat_char();
+ if let Err(err) = self.parse_ident(b"ull") {
+ return err;
+ }
+ de::Error::invalid_type(Unexpected::Unit, exp)
+ }
+ b't' => {
+ self.eat_char();
+ if let Err(err) = self.parse_ident(b"rue") {
+ return err;
+ }
+ de::Error::invalid_type(Unexpected::Bool(true), exp)
+ }
+ b'f' => {
+ self.eat_char();
+ if let Err(err) = self.parse_ident(b"alse") {
+ return err;
+ }
+ de::Error::invalid_type(Unexpected::Bool(false), exp)
+ }
+ b'-' => {
+ self.eat_char();
+ match self.parse_any_number(false) {
+ Ok(n) => n.invalid_type(exp),
+ Err(err) => return err,
+ }
+ }
+ b'0'..=b'9' => match self.parse_any_number(true) {
+ Ok(n) => n.invalid_type(exp),
+ Err(err) => return err,
+ },
+ b'"' => {
+ self.eat_char();
+ self.scratch.clear();
+ match self.read.parse_str(&mut self.scratch) {
+ Ok(s) => de::Error::invalid_type(Unexpected::Str(&s), exp),
+ Err(err) => return err,
+ }
+ }
+ b'[' => de::Error::invalid_type(Unexpected::Seq, exp),
+ b'{' => de::Error::invalid_type(Unexpected::Map, exp),
+ _ => self.peek_error(ErrorCode::ExpectedSomeValue),
+ };
+
+ self.fix_position(err)
+ }
+
+ fn deserialize_number<V>(&mut self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b'-' => {
+ self.eat_char();
+ tri!(self.parse_integer(false)).visit(visitor)
+ }
+ b'0'..=b'9' => tri!(self.parse_integer(true)).visit(visitor),
+ _ => Err(self.peek_invalid_type(&visitor)),
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ fn scan_integer128(&mut self, buf: &mut String) -> Result<()> {
+ match tri!(self.next_char_or_null()) {
+ b'0' => {
+ buf.push('0');
+ // There can be only one leading '0'.
+ match tri!(self.peek_or_null()) {
+ b'0'..=b'9' => Err(self.peek_error(ErrorCode::InvalidNumber)),
+ _ => Ok(()),
+ }
+ }
+ c @ b'1'..=b'9' => {
+ buf.push(c as char);
+ while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ buf.push(c as char);
+ }
+ Ok(())
+ }
+ _ => Err(self.error(ErrorCode::InvalidNumber)),
+ }
+ }
+
+ #[cold]
+ fn fix_position(&self, err: Error) -> Error {
+ err.fix_position(move |code| self.error(code))
+ }
+
+ fn parse_ident(&mut self, ident: &[u8]) -> Result<()> {
+ for expected in ident {
+ match tri!(self.next_char()) {
+ None => {
+ return Err(self.error(ErrorCode::EofWhileParsingValue));
+ }
+ Some(next) => {
+ if next != *expected {
+ return Err(self.error(ErrorCode::ExpectedSomeIdent));
+ }
+ }
+ }
+ }
+
+ Ok(())
+ }
+
+ fn parse_integer(&mut self, positive: bool) -> Result<ParserNumber> {
+ let next = match tri!(self.next_char()) {
+ Some(b) => b,
+ None => {
+ return Err(self.error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ match next {
+ b'0' => {
+ // There can be only one leading '0'.
+ match tri!(self.peek_or_null()) {
+ b'0'..=b'9' => Err(self.peek_error(ErrorCode::InvalidNumber)),
+ _ => self.parse_number(positive, 0),
+ }
+ }
+ c @ b'1'..=b'9' => {
+ let mut significand = (c - b'0') as u64;
+
+ loop {
+ match tri!(self.peek_or_null()) {
+ c @ b'0'..=b'9' => {
+ let digit = (c - b'0') as u64;
+
+ // We need to be careful with overflow. If we can,
+ // try to keep the number as a `u64` until we grow
+ // too large. At that point, switch to parsing the
+ // value as a `f64`.
+ if overflow!(significand * 10 + digit, u64::max_value()) {
+ return Ok(ParserNumber::F64(tri!(
+ self.parse_long_integer(positive, significand),
+ )));
+ }
+
+ self.eat_char();
+ significand = significand * 10 + digit;
+ }
+ _ => {
+ return self.parse_number(positive, significand);
+ }
+ }
+ }
+ }
+ _ => Err(self.error(ErrorCode::InvalidNumber)),
+ }
+ }
+
+ fn parse_number(&mut self, positive: bool, significand: u64) -> Result<ParserNumber> {
+ Ok(match tri!(self.peek_or_null()) {
+ b'.' => ParserNumber::F64(tri!(self.parse_decimal(positive, significand, 0))),
+ b'e' | b'E' => ParserNumber::F64(tri!(self.parse_exponent(positive, significand, 0))),
+ _ => {
+ if positive {
+ ParserNumber::U64(significand)
+ } else {
+ let neg = (significand as i64).wrapping_neg();
+
+ // Convert into a float if we underflow, or on `-0`.
+ if neg >= 0 {
+ ParserNumber::F64(-(significand as f64))
+ } else {
+ ParserNumber::I64(neg)
+ }
+ }
+ }
+ })
+ }
+
+ fn parse_decimal(
+ &mut self,
+ positive: bool,
+ mut significand: u64,
+ exponent_before_decimal_point: i32,
+ ) -> Result<f64> {
+ self.eat_char();
+
+ let mut exponent_after_decimal_point = 0;
+ while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+ let digit = (c - b'0') as u64;
+
+ if overflow!(significand * 10 + digit, u64::max_value()) {
+ let exponent = exponent_before_decimal_point + exponent_after_decimal_point;
+ return self.parse_decimal_overflow(positive, significand, exponent);
+ }
+
+ self.eat_char();
+ significand = significand * 10 + digit;
+ exponent_after_decimal_point -= 1;
+ }
+
+ // Error if there is not at least one digit after the decimal point.
+ if exponent_after_decimal_point == 0 {
+ match tri!(self.peek()) {
+ Some(_) => return Err(self.peek_error(ErrorCode::InvalidNumber)),
+ None => return Err(self.peek_error(ErrorCode::EofWhileParsingValue)),
+ }
+ }
+
+ let exponent = exponent_before_decimal_point + exponent_after_decimal_point;
+ match tri!(self.peek_or_null()) {
+ b'e' | b'E' => self.parse_exponent(positive, significand, exponent),
+ _ => self.f64_from_parts(positive, significand, exponent),
+ }
+ }
+
+ fn parse_exponent(
+ &mut self,
+ positive: bool,
+ significand: u64,
+ starting_exp: i32,
+ ) -> Result<f64> {
+ self.eat_char();
+
+ let positive_exp = match tri!(self.peek_or_null()) {
+ b'+' => {
+ self.eat_char();
+ true
+ }
+ b'-' => {
+ self.eat_char();
+ false
+ }
+ _ => true,
+ };
+
+ let next = match tri!(self.next_char()) {
+ Some(b) => b,
+ None => {
+ return Err(self.error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ // Make sure a digit follows the exponent place.
+ let mut exp = match next {
+ c @ b'0'..=b'9' => (c - b'0') as i32,
+ _ => {
+ return Err(self.error(ErrorCode::InvalidNumber));
+ }
+ };
+
+ while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ let digit = (c - b'0') as i32;
+
+ if overflow!(exp * 10 + digit, i32::max_value()) {
+ let zero_significand = significand == 0;
+ return self.parse_exponent_overflow(positive, zero_significand, positive_exp);
+ }
+
+ exp = exp * 10 + digit;
+ }
+
+ let final_exp = if positive_exp {
+ starting_exp.saturating_add(exp)
+ } else {
+ starting_exp.saturating_sub(exp)
+ };
+
+ self.f64_from_parts(positive, significand, final_exp)
+ }
+
+ #[cfg(feature = "float_roundtrip")]
+ fn f64_from_parts(&mut self, positive: bool, significand: u64, exponent: i32) -> Result<f64> {
+ let f = if self.single_precision {
+ lexical::parse_concise_float::<f32>(significand, exponent) as f64
+ } else {
+ lexical::parse_concise_float::<f64>(significand, exponent)
+ };
+
+ if f.is_infinite() {
+ Err(self.error(ErrorCode::NumberOutOfRange))
+ } else {
+ Ok(if positive { f } else { -f })
+ }
+ }
+
+ #[cfg(not(feature = "float_roundtrip"))]
+ fn f64_from_parts(
+ &mut self,
+ positive: bool,
+ significand: u64,
+ mut exponent: i32,
+ ) -> Result<f64> {
+ let mut f = significand as f64;
+ loop {
+ match POW10.get(exponent.wrapping_abs() as usize) {
+ Some(&pow) => {
+ if exponent >= 0 {
+ f *= pow;
+ if f.is_infinite() {
+ return Err(self.error(ErrorCode::NumberOutOfRange));
+ }
+ } else {
+ f /= pow;
+ }
+ break;
+ }
+ None => {
+ if f == 0.0 {
+ break;
+ }
+ if exponent >= 0 {
+ return Err(self.error(ErrorCode::NumberOutOfRange));
+ }
+ f /= 1e308;
+ exponent += 308;
+ }
+ }
+ }
+ Ok(if positive { f } else { -f })
+ }
+
+ #[cfg(feature = "float_roundtrip")]
+ #[cold]
+ #[inline(never)]
+ fn parse_long_integer(&mut self, positive: bool, partial_significand: u64) -> Result<f64> {
+ // To deserialize floats we'll first push the integer and fraction
+ // parts, both as byte strings, into the scratch buffer and then feed
+ // both slices to lexical's parser. For example if the input is
+ // `12.34e5` we'll push b"1234" into scratch and then pass b"12" and
+ // b"34" to lexical. `integer_end` will be used to track where to split
+ // the scratch buffer.
+ //
+ // Note that lexical expects the integer part to contain *no* leading
+ // zeroes and the fraction part to contain *no* trailing zeroes. The
+ // first requirement is already handled by the integer parsing logic.
+ // The second requirement will be enforced just before passing the
+ // slices to lexical in f64_long_from_parts.
+ self.scratch.clear();
+ self.scratch
+ .extend_from_slice(itoa::Buffer::new().format(partial_significand).as_bytes());
+
+ loop {
+ match tri!(self.peek_or_null()) {
+ c @ b'0'..=b'9' => {
+ self.scratch.push(c);
+ self.eat_char();
+ }
+ b'.' => {
+ self.eat_char();
+ return self.parse_long_decimal(positive, self.scratch.len());
+ }
+ b'e' | b'E' => {
+ return self.parse_long_exponent(positive, self.scratch.len());
+ }
+ _ => {
+ return self.f64_long_from_parts(positive, self.scratch.len(), 0);
+ }
+ }
+ }
+ }
+
+ #[cfg(not(feature = "float_roundtrip"))]
+ #[cold]
+ #[inline(never)]
+ fn parse_long_integer(&mut self, positive: bool, significand: u64) -> Result<f64> {
+ let mut exponent = 0;
+ loop {
+ match tri!(self.peek_or_null()) {
+ b'0'..=b'9' => {
+ self.eat_char();
+ // This could overflow... if your integer is gigabytes long.
+ // Ignore that possibility.
+ exponent += 1;
+ }
+ b'.' => {
+ return self.parse_decimal(positive, significand, exponent);
+ }
+ b'e' | b'E' => {
+ return self.parse_exponent(positive, significand, exponent);
+ }
+ _ => {
+ return self.f64_from_parts(positive, significand, exponent);
+ }
+ }
+ }
+ }
+
+ #[cfg(feature = "float_roundtrip")]
+ #[cold]
+ fn parse_long_decimal(&mut self, positive: bool, integer_end: usize) -> Result<f64> {
+ let mut at_least_one_digit = integer_end < self.scratch.len();
+ while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.scratch.push(c);
+ self.eat_char();
+ at_least_one_digit = true;
+ }
+
+ if !at_least_one_digit {
+ match tri!(self.peek()) {
+ Some(_) => return Err(self.peek_error(ErrorCode::InvalidNumber)),
+ None => return Err(self.peek_error(ErrorCode::EofWhileParsingValue)),
+ }
+ }
+
+ match tri!(self.peek_or_null()) {
+ b'e' | b'E' => self.parse_long_exponent(positive, integer_end),
+ _ => self.f64_long_from_parts(positive, integer_end, 0),
+ }
+ }
+
+ #[cfg(feature = "float_roundtrip")]
+ fn parse_long_exponent(&mut self, positive: bool, integer_end: usize) -> Result<f64> {
+ self.eat_char();
+
+ let positive_exp = match tri!(self.peek_or_null()) {
+ b'+' => {
+ self.eat_char();
+ true
+ }
+ b'-' => {
+ self.eat_char();
+ false
+ }
+ _ => true,
+ };
+
+ let next = match tri!(self.next_char()) {
+ Some(b) => b,
+ None => {
+ return Err(self.error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ // Make sure a digit follows the exponent place.
+ let mut exp = match next {
+ c @ b'0'..=b'9' => (c - b'0') as i32,
+ _ => {
+ return Err(self.error(ErrorCode::InvalidNumber));
+ }
+ };
+
+ while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ let digit = (c - b'0') as i32;
+
+ if overflow!(exp * 10 + digit, i32::max_value()) {
+ let zero_significand = self.scratch.iter().all(|&digit| digit == b'0');
+ return self.parse_exponent_overflow(positive, zero_significand, positive_exp);
+ }
+
+ exp = exp * 10 + digit;
+ }
+
+ let final_exp = if positive_exp { exp } else { -exp };
+
+ self.f64_long_from_parts(positive, integer_end, final_exp)
+ }
+
+ // This cold code should not be inlined into the middle of the hot
+ // decimal-parsing loop above.
+ #[cfg(feature = "float_roundtrip")]
+ #[cold]
+ #[inline(never)]
+ fn parse_decimal_overflow(
+ &mut self,
+ positive: bool,
+ significand: u64,
+ exponent: i32,
+ ) -> Result<f64> {
+ let mut buffer = itoa::Buffer::new();
+ let significand = buffer.format(significand);
+ let fraction_digits = -exponent as usize;
+ self.scratch.clear();
+ if let Some(zeros) = fraction_digits.checked_sub(significand.len() + 1) {
+ self.scratch.extend(iter::repeat(b'0').take(zeros + 1));
+ }
+ self.scratch.extend_from_slice(significand.as_bytes());
+ let integer_end = self.scratch.len() - fraction_digits;
+ self.parse_long_decimal(positive, integer_end)
+ }
+
+ #[cfg(not(feature = "float_roundtrip"))]
+ #[cold]
+ #[inline(never)]
+ fn parse_decimal_overflow(
+ &mut self,
+ positive: bool,
+ significand: u64,
+ exponent: i32,
+ ) -> Result<f64> {
+ // The next multiply/add would overflow, so just ignore all further
+ // digits.
+ while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ }
+
+ match tri!(self.peek_or_null()) {
+ b'e' | b'E' => self.parse_exponent(positive, significand, exponent),
+ _ => self.f64_from_parts(positive, significand, exponent),
+ }
+ }
+
+ // This cold code should not be inlined into the middle of the hot
+ // exponent-parsing loop above.
+ #[cold]
+ #[inline(never)]
+ fn parse_exponent_overflow(
+ &mut self,
+ positive: bool,
+ zero_significand: bool,
+ positive_exp: bool,
+ ) -> Result<f64> {
+ // Error instead of +/- infinity.
+ if !zero_significand && positive_exp {
+ return Err(self.error(ErrorCode::NumberOutOfRange));
+ }
+
+ while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ }
+ Ok(if positive { 0.0 } else { -0.0 })
+ }
+
+ #[cfg(feature = "float_roundtrip")]
+ fn f64_long_from_parts(
+ &mut self,
+ positive: bool,
+ integer_end: usize,
+ exponent: i32,
+ ) -> Result<f64> {
+ let integer = &self.scratch[..integer_end];
+ let fraction = &self.scratch[integer_end..];
+
+ let f = if self.single_precision {
+ lexical::parse_truncated_float::<f32>(integer, fraction, exponent) as f64
+ } else {
+ lexical::parse_truncated_float::<f64>(integer, fraction, exponent)
+ };
+
+ if f.is_infinite() {
+ Err(self.error(ErrorCode::NumberOutOfRange))
+ } else {
+ Ok(if positive { f } else { -f })
+ }
+ }
+
+ fn parse_any_signed_number(&mut self) -> Result<ParserNumber> {
+ let peek = match tri!(self.peek()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b'-' => {
+ self.eat_char();
+ self.parse_any_number(false)
+ }
+ b'0'..=b'9' => self.parse_any_number(true),
+ _ => Err(self.peek_error(ErrorCode::InvalidNumber)),
+ };
+
+ let value = match tri!(self.peek()) {
+ Some(_) => Err(self.peek_error(ErrorCode::InvalidNumber)),
+ None => value,
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ // The de::Error impl creates errors with unknown line and column.
+ // Fill in the position here by looking at the current index in the
+ // input. There is no way to tell whether this should call `error`
+ // or `peek_error` so pick the one that seems correct more often.
+ // Worst case, the position is off by one character.
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ #[cfg(not(feature = "arbitrary_precision"))]
+ fn parse_any_number(&mut self, positive: bool) -> Result<ParserNumber> {
+ self.parse_integer(positive)
+ }
+
+ #[cfg(feature = "arbitrary_precision")]
+ fn parse_any_number(&mut self, positive: bool) -> Result<ParserNumber> {
+ let mut buf = String::with_capacity(16);
+ if !positive {
+ buf.push('-');
+ }
+ self.scan_integer(&mut buf)?;
+ if positive {
+ if let Ok(unsigned) = buf.parse() {
+ return Ok(ParserNumber::U64(unsigned));
+ }
+ } else {
+ if let Ok(signed) = buf.parse() {
+ return Ok(ParserNumber::I64(signed));
+ }
+ }
+ Ok(ParserNumber::String(buf))
+ }
+
+ #[cfg(feature = "arbitrary_precision")]
+ fn scan_or_eof(&mut self, buf: &mut String) -> Result<u8> {
+ match tri!(self.next_char()) {
+ Some(b) => {
+ buf.push(b as char);
+ Ok(b)
+ }
+ None => Err(self.error(ErrorCode::EofWhileParsingValue)),
+ }
+ }
+
+ #[cfg(feature = "arbitrary_precision")]
+ fn scan_integer(&mut self, buf: &mut String) -> Result<()> {
+ match tri!(self.scan_or_eof(buf)) {
+ b'0' => {
+ // There can be only one leading '0'.
+ match tri!(self.peek_or_null()) {
+ b'0'..=b'9' => Err(self.peek_error(ErrorCode::InvalidNumber)),
+ _ => self.scan_number(buf),
+ }
+ }
+ b'1'..=b'9' => loop {
+ match tri!(self.peek_or_null()) {
+ c @ b'0'..=b'9' => {
+ self.eat_char();
+ buf.push(c as char);
+ }
+ _ => {
+ return self.scan_number(buf);
+ }
+ }
+ },
+ _ => Err(self.error(ErrorCode::InvalidNumber)),
+ }
+ }
+
+ #[cfg(feature = "arbitrary_precision")]
+ fn scan_number(&mut self, buf: &mut String) -> Result<()> {
+ match tri!(self.peek_or_null()) {
+ b'.' => self.scan_decimal(buf),
+ e @ b'e' | e @ b'E' => self.scan_exponent(e as char, buf),
+ _ => Ok(()),
+ }
+ }
+
+ #[cfg(feature = "arbitrary_precision")]
+ fn scan_decimal(&mut self, buf: &mut String) -> Result<()> {
+ self.eat_char();
+ buf.push('.');
+
+ let mut at_least_one_digit = false;
+ while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ buf.push(c as char);
+ at_least_one_digit = true;
+ }
+
+ if !at_least_one_digit {
+ match tri!(self.peek()) {
+ Some(_) => return Err(self.peek_error(ErrorCode::InvalidNumber)),
+ None => return Err(self.peek_error(ErrorCode::EofWhileParsingValue)),
+ }
+ }
+
+ match tri!(self.peek_or_null()) {
+ e @ b'e' | e @ b'E' => self.scan_exponent(e as char, buf),
+ _ => Ok(()),
+ }
+ }
+
+ #[cfg(feature = "arbitrary_precision")]
+ fn scan_exponent(&mut self, e: char, buf: &mut String) -> Result<()> {
+ self.eat_char();
+ buf.push(e);
+
+ match tri!(self.peek_or_null()) {
+ b'+' => {
+ self.eat_char();
+ buf.push('+');
+ }
+ b'-' => {
+ self.eat_char();
+ buf.push('-');
+ }
+ _ => {}
+ }
+
+ // Make sure a digit follows the exponent place.
+ match tri!(self.scan_or_eof(buf)) {
+ b'0'..=b'9' => {}
+ _ => {
+ return Err(self.error(ErrorCode::InvalidNumber));
+ }
+ }
+
+ while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ buf.push(c as char);
+ }
+
+ Ok(())
+ }
+
+ fn parse_object_colon(&mut self) -> Result<()> {
+ match tri!(self.parse_whitespace()) {
+ Some(b':') => {
+ self.eat_char();
+ Ok(())
+ }
+ Some(_) => Err(self.peek_error(ErrorCode::ExpectedColon)),
+ None => Err(self.peek_error(ErrorCode::EofWhileParsingObject)),
+ }
+ }
+
+ fn end_seq(&mut self) -> Result<()> {
+ match tri!(self.parse_whitespace()) {
+ Some(b']') => {
+ self.eat_char();
+ Ok(())
+ }
+ Some(b',') => {
+ self.eat_char();
+ match self.parse_whitespace() {
+ Ok(Some(b']')) => Err(self.peek_error(ErrorCode::TrailingComma)),
+ _ => Err(self.peek_error(ErrorCode::TrailingCharacters)),
+ }
+ }
+ Some(_) => Err(self.peek_error(ErrorCode::TrailingCharacters)),
+ None => Err(self.peek_error(ErrorCode::EofWhileParsingList)),
+ }
+ }
+
+ fn end_map(&mut self) -> Result<()> {
+ match tri!(self.parse_whitespace()) {
+ Some(b'}') => {
+ self.eat_char();
+ Ok(())
+ }
+ Some(b',') => Err(self.peek_error(ErrorCode::TrailingComma)),
+ Some(_) => Err(self.peek_error(ErrorCode::TrailingCharacters)),
+ None => Err(self.peek_error(ErrorCode::EofWhileParsingObject)),
+ }
+ }
+
+ fn ignore_value(&mut self) -> Result<()> {
+ self.scratch.clear();
+ let mut enclosing = None;
+
+ loop {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let frame = match peek {
+ b'n' => {
+ self.eat_char();
+ tri!(self.parse_ident(b"ull"));
+ None
+ }
+ b't' => {
+ self.eat_char();
+ tri!(self.parse_ident(b"rue"));
+ None
+ }
+ b'f' => {
+ self.eat_char();
+ tri!(self.parse_ident(b"alse"));
+ None
+ }
+ b'-' => {
+ self.eat_char();
+ tri!(self.ignore_integer());
+ None
+ }
+ b'0'..=b'9' => {
+ tri!(self.ignore_integer());
+ None
+ }
+ b'"' => {
+ self.eat_char();
+ tri!(self.read.ignore_str());
+ None
+ }
+ frame @ b'[' | frame @ b'{' => {
+ self.scratch.extend(enclosing.take());
+ self.eat_char();
+ Some(frame)
+ }
+ _ => return Err(self.peek_error(ErrorCode::ExpectedSomeValue)),
+ };
+
+ let (mut accept_comma, mut frame) = match frame {
+ Some(frame) => (false, frame),
+ None => match enclosing.take() {
+ Some(frame) => (true, frame),
+ None => match self.scratch.pop() {
+ Some(frame) => (true, frame),
+ None => return Ok(()),
+ },
+ },
+ };
+
+ loop {
+ match tri!(self.parse_whitespace()) {
+ Some(b',') if accept_comma => {
+ self.eat_char();
+ break;
+ }
+ Some(b']') if frame == b'[' => {}
+ Some(b'}') if frame == b'{' => {}
+ Some(_) => {
+ if accept_comma {
+ return Err(self.peek_error(match frame {
+ b'[' => ErrorCode::ExpectedListCommaOrEnd,
+ b'{' => ErrorCode::ExpectedObjectCommaOrEnd,
+ _ => unreachable!(),
+ }));
+ } else {
+ break;
+ }
+ }
+ None => {
+ return Err(self.peek_error(match frame {
+ b'[' => ErrorCode::EofWhileParsingList,
+ b'{' => ErrorCode::EofWhileParsingObject,
+ _ => unreachable!(),
+ }));
+ }
+ }
+
+ self.eat_char();
+ frame = match self.scratch.pop() {
+ Some(frame) => frame,
+ None => return Ok(()),
+ };
+ accept_comma = true;
+ }
+
+ if frame == b'{' {
+ match tri!(self.parse_whitespace()) {
+ Some(b'"') => self.eat_char(),
+ Some(_) => return Err(self.peek_error(ErrorCode::KeyMustBeAString)),
+ None => return Err(self.peek_error(ErrorCode::EofWhileParsingObject)),
+ }
+ tri!(self.read.ignore_str());
+ match tri!(self.parse_whitespace()) {
+ Some(b':') => self.eat_char(),
+ Some(_) => return Err(self.peek_error(ErrorCode::ExpectedColon)),
+ None => return Err(self.peek_error(ErrorCode::EofWhileParsingObject)),
+ }
+ }
+
+ enclosing = Some(frame);
+ }
+ }
+
+ fn ignore_integer(&mut self) -> Result<()> {
+ match tri!(self.next_char_or_null()) {
+ b'0' => {
+ // There can be only one leading '0'.
+ if let b'0'..=b'9' = tri!(self.peek_or_null()) {
+ return Err(self.peek_error(ErrorCode::InvalidNumber));
+ }
+ }
+ b'1'..=b'9' => {
+ while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ }
+ }
+ _ => {
+ return Err(self.error(ErrorCode::InvalidNumber));
+ }
+ }
+
+ match tri!(self.peek_or_null()) {
+ b'.' => self.ignore_decimal(),
+ b'e' | b'E' => self.ignore_exponent(),
+ _ => Ok(()),
+ }
+ }
+
+ fn ignore_decimal(&mut self) -> Result<()> {
+ self.eat_char();
+
+ let mut at_least_one_digit = false;
+ while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ at_least_one_digit = true;
+ }
+
+ if !at_least_one_digit {
+ return Err(self.peek_error(ErrorCode::InvalidNumber));
+ }
+
+ match tri!(self.peek_or_null()) {
+ b'e' | b'E' => self.ignore_exponent(),
+ _ => Ok(()),
+ }
+ }
+
+ fn ignore_exponent(&mut self) -> Result<()> {
+ self.eat_char();
+
+ match tri!(self.peek_or_null()) {
+ b'+' | b'-' => self.eat_char(),
+ _ => {}
+ }
+
+ // Make sure a digit follows the exponent place.
+ match tri!(self.next_char_or_null()) {
+ b'0'..=b'9' => {}
+ _ => {
+ return Err(self.error(ErrorCode::InvalidNumber));
+ }
+ }
+
+ while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+ self.eat_char();
+ }
+
+ Ok(())
+ }
+
+ #[cfg(feature = "raw_value")]
+ fn deserialize_raw_value<V>(&mut self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.parse_whitespace()?;
+ self.read.begin_raw_buffering();
+ self.ignore_value()?;
+ self.read.end_raw_buffering(visitor)
+ }
+}
+
+impl FromStr for Number {
+ type Err = Error;
+
+ fn from_str(s: &str) -> result::Result<Self, Self::Err> {
+ Deserializer::from_str(s)
+ .parse_any_signed_number()
+ .map(Into::into)
+ }
+}
+
+#[cfg(not(feature = "float_roundtrip"))]
+static POW10: [f64; 309] = [
+ 1e000, 1e001, 1e002, 1e003, 1e004, 1e005, 1e006, 1e007, 1e008, 1e009, //
+ 1e010, 1e011, 1e012, 1e013, 1e014, 1e015, 1e016, 1e017, 1e018, 1e019, //
+ 1e020, 1e021, 1e022, 1e023, 1e024, 1e025, 1e026, 1e027, 1e028, 1e029, //
+ 1e030, 1e031, 1e032, 1e033, 1e034, 1e035, 1e036, 1e037, 1e038, 1e039, //
+ 1e040, 1e041, 1e042, 1e043, 1e044, 1e045, 1e046, 1e047, 1e048, 1e049, //
+ 1e050, 1e051, 1e052, 1e053, 1e054, 1e055, 1e056, 1e057, 1e058, 1e059, //
+ 1e060, 1e061, 1e062, 1e063, 1e064, 1e065, 1e066, 1e067, 1e068, 1e069, //
+ 1e070, 1e071, 1e072, 1e073, 1e074, 1e075, 1e076, 1e077, 1e078, 1e079, //
+ 1e080, 1e081, 1e082, 1e083, 1e084, 1e085, 1e086, 1e087, 1e088, 1e089, //
+ 1e090, 1e091, 1e092, 1e093, 1e094, 1e095, 1e096, 1e097, 1e098, 1e099, //
+ 1e100, 1e101, 1e102, 1e103, 1e104, 1e105, 1e106, 1e107, 1e108, 1e109, //
+ 1e110, 1e111, 1e112, 1e113, 1e114, 1e115, 1e116, 1e117, 1e118, 1e119, //
+ 1e120, 1e121, 1e122, 1e123, 1e124, 1e125, 1e126, 1e127, 1e128, 1e129, //
+ 1e130, 1e131, 1e132, 1e133, 1e134, 1e135, 1e136, 1e137, 1e138, 1e139, //
+ 1e140, 1e141, 1e142, 1e143, 1e144, 1e145, 1e146, 1e147, 1e148, 1e149, //
+ 1e150, 1e151, 1e152, 1e153, 1e154, 1e155, 1e156, 1e157, 1e158, 1e159, //
+ 1e160, 1e161, 1e162, 1e163, 1e164, 1e165, 1e166, 1e167, 1e168, 1e169, //
+ 1e170, 1e171, 1e172, 1e173, 1e174, 1e175, 1e176, 1e177, 1e178, 1e179, //
+ 1e180, 1e181, 1e182, 1e183, 1e184, 1e185, 1e186, 1e187, 1e188, 1e189, //
+ 1e190, 1e191, 1e192, 1e193, 1e194, 1e195, 1e196, 1e197, 1e198, 1e199, //
+ 1e200, 1e201, 1e202, 1e203, 1e204, 1e205, 1e206, 1e207, 1e208, 1e209, //
+ 1e210, 1e211, 1e212, 1e213, 1e214, 1e215, 1e216, 1e217, 1e218, 1e219, //
+ 1e220, 1e221, 1e222, 1e223, 1e224, 1e225, 1e226, 1e227, 1e228, 1e229, //
+ 1e230, 1e231, 1e232, 1e233, 1e234, 1e235, 1e236, 1e237, 1e238, 1e239, //
+ 1e240, 1e241, 1e242, 1e243, 1e244, 1e245, 1e246, 1e247, 1e248, 1e249, //
+ 1e250, 1e251, 1e252, 1e253, 1e254, 1e255, 1e256, 1e257, 1e258, 1e259, //
+ 1e260, 1e261, 1e262, 1e263, 1e264, 1e265, 1e266, 1e267, 1e268, 1e269, //
+ 1e270, 1e271, 1e272, 1e273, 1e274, 1e275, 1e276, 1e277, 1e278, 1e279, //
+ 1e280, 1e281, 1e282, 1e283, 1e284, 1e285, 1e286, 1e287, 1e288, 1e289, //
+ 1e290, 1e291, 1e292, 1e293, 1e294, 1e295, 1e296, 1e297, 1e298, 1e299, //
+ 1e300, 1e301, 1e302, 1e303, 1e304, 1e305, 1e306, 1e307, 1e308,
+];
+
+macro_rules! deserialize_number {
+ ($method:ident) => {
+ fn $method<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.deserialize_number(visitor)
+ }
+ };
+}
+
+#[cfg(not(feature = "unbounded_depth"))]
+macro_rules! if_checking_recursion_limit {
+ ($($body:tt)*) => {
+ $($body)*
+ };
+}
+
+#[cfg(feature = "unbounded_depth")]
+macro_rules! if_checking_recursion_limit {
+ ($this:ident $($body:tt)*) => {
+ if !$this.disable_recursion_limit {
+ $this $($body)*
+ }
+ };
+}
+
+macro_rules! check_recursion {
+ ($this:ident $($body:tt)*) => {
+ if_checking_recursion_limit! {
+ $this.remaining_depth -= 1;
+ if $this.remaining_depth == 0 {
+ return Err($this.peek_error(ErrorCode::RecursionLimitExceeded));
+ }
+ }
+
+ $this $($body)*
+
+ if_checking_recursion_limit! {
+ $this.remaining_depth += 1;
+ }
+ };
+}
+
+impl<'de, 'a, R: Read<'de>> de::Deserializer<'de> for &'a mut Deserializer<R> {
+ type Error = Error;
+
+ #[inline]
+ fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b'n' => {
+ self.eat_char();
+ tri!(self.parse_ident(b"ull"));
+ visitor.visit_unit()
+ }
+ b't' => {
+ self.eat_char();
+ tri!(self.parse_ident(b"rue"));
+ visitor.visit_bool(true)
+ }
+ b'f' => {
+ self.eat_char();
+ tri!(self.parse_ident(b"alse"));
+ visitor.visit_bool(false)
+ }
+ b'-' => {
+ self.eat_char();
+ tri!(self.parse_any_number(false)).visit(visitor)
+ }
+ b'0'..=b'9' => tri!(self.parse_any_number(true)).visit(visitor),
+ b'"' => {
+ self.eat_char();
+ self.scratch.clear();
+ match tri!(self.read.parse_str(&mut self.scratch)) {
+ Reference::Borrowed(s) => visitor.visit_borrowed_str(s),
+ Reference::Copied(s) => visitor.visit_str(s),
+ }
+ }
+ b'[' => {
+ check_recursion! {
+ self.eat_char();
+ let ret = visitor.visit_seq(SeqAccess::new(self));
+ }
+
+ match (ret, self.end_seq()) {
+ (Ok(ret), Ok(())) => Ok(ret),
+ (Err(err), _) | (_, Err(err)) => Err(err),
+ }
+ }
+ b'{' => {
+ check_recursion! {
+ self.eat_char();
+ let ret = visitor.visit_map(MapAccess::new(self));
+ }
+
+ match (ret, self.end_map()) {
+ (Ok(ret), Ok(())) => Ok(ret),
+ (Err(err), _) | (_, Err(err)) => Err(err),
+ }
+ }
+ _ => Err(self.peek_error(ErrorCode::ExpectedSomeValue)),
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ // The de::Error impl creates errors with unknown line and column.
+ // Fill in the position here by looking at the current index in the
+ // input. There is no way to tell whether this should call `error`
+ // or `peek_error` so pick the one that seems correct more often.
+ // Worst case, the position is off by one character.
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b't' => {
+ self.eat_char();
+ tri!(self.parse_ident(b"rue"));
+ visitor.visit_bool(true)
+ }
+ b'f' => {
+ self.eat_char();
+ tri!(self.parse_ident(b"alse"));
+ visitor.visit_bool(false)
+ }
+ _ => Err(self.peek_invalid_type(&visitor)),
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ deserialize_number!(deserialize_i8);
+ deserialize_number!(deserialize_i16);
+ deserialize_number!(deserialize_i32);
+ deserialize_number!(deserialize_i64);
+ deserialize_number!(deserialize_u8);
+ deserialize_number!(deserialize_u16);
+ deserialize_number!(deserialize_u32);
+ deserialize_number!(deserialize_u64);
+ #[cfg(not(feature = "float_roundtrip"))]
+ deserialize_number!(deserialize_f32);
+ deserialize_number!(deserialize_f64);
+
+ #[cfg(feature = "float_roundtrip")]
+ fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.single_precision = true;
+ let val = self.deserialize_number(visitor);
+ self.single_precision = false;
+ val
+ }
+
+ fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let mut buf = String::new();
+
+ match tri!(self.parse_whitespace()) {
+ Some(b'-') => {
+ self.eat_char();
+ buf.push('-');
+ }
+ Some(_) => {}
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ tri!(self.scan_integer128(&mut buf));
+
+ let value = match buf.parse() {
+ Ok(int) => visitor.visit_i128(int),
+ Err(_) => {
+ return Err(self.error(ErrorCode::NumberOutOfRange));
+ }
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ match tri!(self.parse_whitespace()) {
+ Some(b'-') => {
+ return Err(self.peek_error(ErrorCode::NumberOutOfRange));
+ }
+ Some(_) => {}
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ }
+
+ let mut buf = String::new();
+ tri!(self.scan_integer128(&mut buf));
+
+ let value = match buf.parse() {
+ Ok(int) => visitor.visit_u128(int),
+ Err(_) => {
+ return Err(self.error(ErrorCode::NumberOutOfRange));
+ }
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ fn deserialize_char<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.deserialize_str(visitor)
+ }
+
+ fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b'"' => {
+ self.eat_char();
+ self.scratch.clear();
+ match tri!(self.read.parse_str(&mut self.scratch)) {
+ Reference::Borrowed(s) => visitor.visit_borrowed_str(s),
+ Reference::Copied(s) => visitor.visit_str(s),
+ }
+ }
+ _ => Err(self.peek_invalid_type(&visitor)),
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ fn deserialize_string<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.deserialize_str(visitor)
+ }
+
+ /// Parses a JSON string as bytes. Note that this function does not check
+ /// whether the bytes represent a valid UTF-8 string.
+ ///
+ /// The relevant part of the JSON specification is Section 8.2 of [RFC
+ /// 7159]:
+ ///
+ /// > When all the strings represented in a JSON text are composed entirely
+ /// > of Unicode characters (however escaped), then that JSON text is
+ /// > interoperable in the sense that all software implementations that
+ /// > parse it will agree on the contents of names and of string values in
+ /// > objects and arrays.
+ /// >
+ /// > However, the ABNF in this specification allows member names and string
+ /// > values to contain bit sequences that cannot encode Unicode characters;
+ /// > for example, "\uDEAD" (a single unpaired UTF-16 surrogate). Instances
+ /// > of this have been observed, for example, when a library truncates a
+ /// > UTF-16 string without checking whether the truncation split a
+ /// > surrogate pair. The behavior of software that receives JSON texts
+ /// > containing such values is unpredictable; for example, implementations
+ /// > might return different values for the length of a string value or even
+ /// > suffer fatal runtime exceptions.
+ ///
+ /// [RFC 7159]: https://tools.ietf.org/html/rfc7159
+ ///
+ /// The behavior of serde_json is specified to fail on non-UTF-8 strings
+ /// when deserializing into Rust UTF-8 string types such as String, and
+ /// succeed with non-UTF-8 bytes when deserializing using this method.
+ ///
+ /// Escape sequences are processed as usual, and for `\uXXXX` escapes it is
+ /// still checked if the hex number represents a valid Unicode code point.
+ ///
+ /// # Examples
+ ///
+ /// You can use this to parse JSON strings containing invalid UTF-8 bytes,
+ /// or unpaired surrogates.
+ ///
+ /// ```
+ /// use serde_bytes::ByteBuf;
+ ///
+ /// fn look_at_bytes() -> Result<(), serde_json::Error> {
+ /// let json_data = b"\"some bytes: \xe5\x00\xe5\"";
+ /// let bytes: ByteBuf = serde_json::from_slice(json_data)?;
+ ///
+ /// assert_eq!(b'\xe5', bytes[12]);
+ /// assert_eq!(b'\0', bytes[13]);
+ /// assert_eq!(b'\xe5', bytes[14]);
+ ///
+ /// Ok(())
+ /// }
+ /// #
+ /// # look_at_bytes().unwrap();
+ /// ```
+ ///
+ /// Backslash escape sequences like `\n` are still interpreted and required
+ /// to be valid. `\u` escape sequences are required to represent a valid
+ /// Unicode code point or lone surrogate.
+ ///
+ /// ```
+ /// use serde_bytes::ByteBuf;
+ ///
+ /// fn look_at_bytes() -> Result<(), serde_json::Error> {
+ /// let json_data = b"\"lone surrogate: \\uD801\"";
+ /// let bytes: ByteBuf = serde_json::from_slice(json_data)?;
+ /// let expected = b"lone surrogate: \xED\xA0\x81";
+ /// assert_eq!(expected, bytes.as_slice());
+ /// Ok(())
+ /// }
+ /// #
+ /// # look_at_bytes();
+ /// ```
+ fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b'"' => {
+ self.eat_char();
+ self.scratch.clear();
+ match tri!(self.read.parse_str_raw(&mut self.scratch)) {
+ Reference::Borrowed(b) => visitor.visit_borrowed_bytes(b),
+ Reference::Copied(b) => visitor.visit_bytes(b),
+ }
+ }
+ b'[' => self.deserialize_seq(visitor),
+ _ => Err(self.peek_invalid_type(&visitor)),
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ #[inline]
+ fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.deserialize_bytes(visitor)
+ }
+
+ /// Parses a `null` as a None, and any other values as a `Some(...)`.
+ #[inline]
+ fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ match tri!(self.parse_whitespace()) {
+ Some(b'n') => {
+ self.eat_char();
+ tri!(self.parse_ident(b"ull"));
+ visitor.visit_none()
+ }
+ _ => visitor.visit_some(self),
+ }
+ }
+
+ fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b'n' => {
+ self.eat_char();
+ tri!(self.parse_ident(b"ull"));
+ visitor.visit_unit()
+ }
+ _ => Err(self.peek_invalid_type(&visitor)),
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ fn deserialize_unit_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.deserialize_unit(visitor)
+ }
+
+ /// Parses a newtype struct as the underlying value.
+ #[inline]
+ fn deserialize_newtype_struct<V>(self, name: &str, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ #[cfg(feature = "raw_value")]
+ {
+ if name == crate::raw::TOKEN {
+ return self.deserialize_raw_value(visitor);
+ }
+ }
+
+ let _ = name;
+ visitor.visit_newtype_struct(self)
+ }
+
+ fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b'[' => {
+ check_recursion! {
+ self.eat_char();
+ let ret = visitor.visit_seq(SeqAccess::new(self));
+ }
+
+ match (ret, self.end_seq()) {
+ (Ok(ret), Ok(())) => Ok(ret),
+ (Err(err), _) | (_, Err(err)) => Err(err),
+ }
+ }
+ _ => Err(self.peek_invalid_type(&visitor)),
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.deserialize_seq(visitor)
+ }
+
+ fn deserialize_tuple_struct<V>(
+ self,
+ _name: &'static str,
+ _len: usize,
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.deserialize_seq(visitor)
+ }
+
+ fn deserialize_map<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b'{' => {
+ check_recursion! {
+ self.eat_char();
+ let ret = visitor.visit_map(MapAccess::new(self));
+ }
+
+ match (ret, self.end_map()) {
+ (Ok(ret), Ok(())) => Ok(ret),
+ (Err(err), _) | (_, Err(err)) => Err(err),
+ }
+ }
+ _ => Err(self.peek_invalid_type(&visitor)),
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ fn deserialize_struct<V>(
+ self,
+ _name: &'static str,
+ _fields: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ let peek = match tri!(self.parse_whitespace()) {
+ Some(b) => b,
+ None => {
+ return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+ }
+ };
+
+ let value = match peek {
+ b'[' => {
+ check_recursion! {
+ self.eat_char();
+ let ret = visitor.visit_seq(SeqAccess::new(self));
+ }
+
+ match (ret, self.end_seq()) {
+ (Ok(ret), Ok(())) => Ok(ret),
+ (Err(err), _) | (_, Err(err)) => Err(err),
+ }
+ }
+ b'{' => {
+ check_recursion! {
+ self.eat_char();
+ let ret = visitor.visit_map(MapAccess::new(self));
+ }
+
+ match (ret, self.end_map()) {
+ (Ok(ret), Ok(())) => Ok(ret),
+ (Err(err), _) | (_, Err(err)) => Err(err),
+ }
+ }
+ _ => Err(self.peek_invalid_type(&visitor)),
+ };
+
+ match value {
+ Ok(value) => Ok(value),
+ Err(err) => Err(self.fix_position(err)),
+ }
+ }
+
+ /// Parses an enum as an object like `{"$KEY":$VALUE}`, where $VALUE is either a straight
+ /// value, a `[..]`, or a `{..}`.
+ #[inline]
+ fn deserialize_enum<V>(
+ self,
+ _name: &str,
+ _variants: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ match tri!(self.parse_whitespace()) {
+ Some(b'{') => {
+ check_recursion! {
+ self.eat_char();
+ let value = tri!(visitor.visit_enum(VariantAccess::new(self)));
+ }
+
+ match tri!(self.parse_whitespace()) {
+ Some(b'}') => {
+ self.eat_char();
+ Ok(value)
+ }
+ Some(_) => Err(self.error(ErrorCode::ExpectedSomeValue)),
+ None => Err(self.error(ErrorCode::EofWhileParsingObject)),
+ }
+ }
+ Some(b'"') => visitor.visit_enum(UnitVariantAccess::new(self)),
+ Some(_) => Err(self.peek_error(ErrorCode::ExpectedSomeValue)),
+ None => Err(self.peek_error(ErrorCode::EofWhileParsingValue)),
+ }
+ }
+
+ fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.deserialize_str(visitor)
+ }
+
+ fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ tri!(self.ignore_value());
+ visitor.visit_unit()
+ }
+}
+
+struct SeqAccess<'a, R: 'a> {
+ de: &'a mut Deserializer<R>,
+ first: bool,
+}
+
+impl<'a, R: 'a> SeqAccess<'a, R> {
+ fn new(de: &'a mut Deserializer<R>) -> Self {
+ SeqAccess { de, first: true }
+ }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::SeqAccess<'de> for SeqAccess<'a, R> {
+ type Error = Error;
+
+ fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
+ where
+ T: de::DeserializeSeed<'de>,
+ {
+ let peek = match tri!(self.de.parse_whitespace()) {
+ Some(b']') => {
+ return Ok(None);
+ }
+ Some(b',') if !self.first => {
+ self.de.eat_char();
+ tri!(self.de.parse_whitespace())
+ }
+ Some(b) => {
+ if self.first {
+ self.first = false;
+ Some(b)
+ } else {
+ return Err(self.de.peek_error(ErrorCode::ExpectedListCommaOrEnd));
+ }
+ }
+ None => {
+ return Err(self.de.peek_error(ErrorCode::EofWhileParsingList));
+ }
+ };
+
+ match peek {
+ Some(b']') => Err(self.de.peek_error(ErrorCode::TrailingComma)),
+ Some(_) => Ok(Some(tri!(seed.deserialize(&mut *self.de)))),
+ None => Err(self.de.peek_error(ErrorCode::EofWhileParsingValue)),
+ }
+ }
+}
+
+struct MapAccess<'a, R: 'a> {
+ de: &'a mut Deserializer<R>,
+ first: bool,
+}
+
+impl<'a, R: 'a> MapAccess<'a, R> {
+ fn new(de: &'a mut Deserializer<R>) -> Self {
+ MapAccess { de, first: true }
+ }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::MapAccess<'de> for MapAccess<'a, R> {
+ type Error = Error;
+
+ fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
+ where
+ K: de::DeserializeSeed<'de>,
+ {
+ let peek = match tri!(self.de.parse_whitespace()) {
+ Some(b'}') => {
+ return Ok(None);
+ }
+ Some(b',') if !self.first => {
+ self.de.eat_char();
+ tri!(self.de.parse_whitespace())
+ }
+ Some(b) => {
+ if self.first {
+ self.first = false;
+ Some(b)
+ } else {
+ return Err(self.de.peek_error(ErrorCode::ExpectedObjectCommaOrEnd));
+ }
+ }
+ None => {
+ return Err(self.de.peek_error(ErrorCode::EofWhileParsingObject));
+ }
+ };
+
+ match peek {
+ Some(b'"') => seed.deserialize(MapKey { de: &mut *self.de }).map(Some),
+ Some(b'}') => Err(self.de.peek_error(ErrorCode::TrailingComma)),
+ Some(_) => Err(self.de.peek_error(ErrorCode::KeyMustBeAString)),
+ None => Err(self.de.peek_error(ErrorCode::EofWhileParsingValue)),
+ }
+ }
+
+ fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value>
+ where
+ V: de::DeserializeSeed<'de>,
+ {
+ tri!(self.de.parse_object_colon());
+
+ seed.deserialize(&mut *self.de)
+ }
+}
+
+struct VariantAccess<'a, R: 'a> {
+ de: &'a mut Deserializer<R>,
+}
+
+impl<'a, R: 'a> VariantAccess<'a, R> {
+ fn new(de: &'a mut Deserializer<R>) -> Self {
+ VariantAccess { de }
+ }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::EnumAccess<'de> for VariantAccess<'a, R> {
+ type Error = Error;
+ type Variant = Self;
+
+ fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self)>
+ where
+ V: de::DeserializeSeed<'de>,
+ {
+ let val = tri!(seed.deserialize(&mut *self.de));
+ tri!(self.de.parse_object_colon());
+ Ok((val, self))
+ }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::VariantAccess<'de> for VariantAccess<'a, R> {
+ type Error = Error;
+
+ fn unit_variant(self) -> Result<()> {
+ de::Deserialize::deserialize(self.de)
+ }
+
+ fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value>
+ where
+ T: de::DeserializeSeed<'de>,
+ {
+ seed.deserialize(self.de)
+ }
+
+ fn tuple_variant<V>(self, _len: usize, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ de::Deserializer::deserialize_seq(self.de, visitor)
+ }
+
+ fn struct_variant<V>(self, fields: &'static [&'static str], visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ de::Deserializer::deserialize_struct(self.de, "", fields, visitor)
+ }
+}
+
+struct UnitVariantAccess<'a, R: 'a> {
+ de: &'a mut Deserializer<R>,
+}
+
+impl<'a, R: 'a> UnitVariantAccess<'a, R> {
+ fn new(de: &'a mut Deserializer<R>) -> Self {
+ UnitVariantAccess { de }
+ }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::EnumAccess<'de> for UnitVariantAccess<'a, R> {
+ type Error = Error;
+ type Variant = Self;
+
+ fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self)>
+ where
+ V: de::DeserializeSeed<'de>,
+ {
+ let variant = tri!(seed.deserialize(&mut *self.de));
+ Ok((variant, self))
+ }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::VariantAccess<'de> for UnitVariantAccess<'a, R> {
+ type Error = Error;
+
+ fn unit_variant(self) -> Result<()> {
+ Ok(())
+ }
+
+ fn newtype_variant_seed<T>(self, _seed: T) -> Result<T::Value>
+ where
+ T: de::DeserializeSeed<'de>,
+ {
+ Err(de::Error::invalid_type(
+ Unexpected::UnitVariant,
+ &"newtype variant",
+ ))
+ }
+
+ fn tuple_variant<V>(self, _len: usize, _visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ Err(de::Error::invalid_type(
+ Unexpected::UnitVariant,
+ &"tuple variant",
+ ))
+ }
+
+ fn struct_variant<V>(self, _fields: &'static [&'static str], _visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ Err(de::Error::invalid_type(
+ Unexpected::UnitVariant,
+ &"struct variant",
+ ))
+ }
+}
+
+/// Only deserialize from this after peeking a '"' byte! Otherwise it may
+/// deserialize invalid JSON successfully.
+struct MapKey<'a, R: 'a> {
+ de: &'a mut Deserializer<R>,
+}
+
+macro_rules! deserialize_integer_key {
+ ($method:ident => $visit:ident) => {
+ fn $method<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.de.eat_char();
+ self.de.scratch.clear();
+ let string = tri!(self.de.read.parse_str(&mut self.de.scratch));
+ match (string.parse(), string) {
+ (Ok(integer), _) => visitor.$visit(integer),
+ (Err(_), Reference::Borrowed(s)) => visitor.visit_borrowed_str(s),
+ (Err(_), Reference::Copied(s)) => visitor.visit_str(s),
+ }
+ }
+ };
+}
+
+impl<'de, 'a, R> de::Deserializer<'de> for MapKey<'a, R>
+where
+ R: Read<'de>,
+{
+ type Error = Error;
+
+ #[inline]
+ fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.de.eat_char();
+ self.de.scratch.clear();
+ match tri!(self.de.read.parse_str(&mut self.de.scratch)) {
+ Reference::Borrowed(s) => visitor.visit_borrowed_str(s),
+ Reference::Copied(s) => visitor.visit_str(s),
+ }
+ }
+
+ deserialize_integer_key!(deserialize_i8 => visit_i8);
+ deserialize_integer_key!(deserialize_i16 => visit_i16);
+ deserialize_integer_key!(deserialize_i32 => visit_i32);
+ deserialize_integer_key!(deserialize_i64 => visit_i64);
+ deserialize_integer_key!(deserialize_i128 => visit_i128);
+ deserialize_integer_key!(deserialize_u8 => visit_u8);
+ deserialize_integer_key!(deserialize_u16 => visit_u16);
+ deserialize_integer_key!(deserialize_u32 => visit_u32);
+ deserialize_integer_key!(deserialize_u64 => visit_u64);
+ deserialize_integer_key!(deserialize_u128 => visit_u128);
+
+ #[inline]
+ fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ // Map keys cannot be null.
+ visitor.visit_some(self)
+ }
+
+ #[inline]
+ fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ #[cfg(feature = "raw_value")]
+ {
+ if name == crate::raw::TOKEN {
+ return self.de.deserialize_raw_value(visitor);
+ }
+ }
+
+ let _ = name;
+ visitor.visit_newtype_struct(self)
+ }
+
+ #[inline]
+ fn deserialize_enum<V>(
+ self,
+ name: &'static str,
+ variants: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.de.deserialize_enum(name, variants, visitor)
+ }
+
+ #[inline]
+ fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.de.deserialize_bytes(visitor)
+ }
+
+ #[inline]
+ fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: de::Visitor<'de>,
+ {
+ self.de.deserialize_bytes(visitor)
+ }
+
+ forward_to_deserialize_any! {
+ bool f32 f64 char str string unit unit_struct seq tuple tuple_struct map
+ struct identifier ignored_any
+ }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+/// Iterator that deserializes a stream into multiple JSON values.
+///
+/// A stream deserializer can be created from any JSON deserializer using the
+/// `Deserializer::into_iter` method.
+///
+/// The data can consist of any JSON value. Values need to be a self-delineating value e.g.
+/// arrays, objects, or strings, or be followed by whitespace or a self-delineating value.
+///
+/// ```
+/// use serde_json::{Deserializer, Value};
+///
+/// fn main() {
+/// let data = "{\"k\": 3}1\"cool\"\"stuff\" 3{} [0, 1, 2]";
+///
+/// let stream = Deserializer::from_str(data).into_iter::<Value>();
+///
+/// for value in stream {
+/// println!("{}", value.unwrap());
+/// }
+/// }
+/// ```
+pub struct StreamDeserializer<'de, R, T> {
+ de: Deserializer<R>,
+ offset: usize,
+ failed: bool,
+ output: PhantomData<T>,
+ lifetime: PhantomData<&'de ()>,
+}
+
+impl<'de, R, T> StreamDeserializer<'de, R, T>
+where
+ R: read::Read<'de>,
+ T: de::Deserialize<'de>,
+{
+ /// Create a JSON stream deserializer from one of the possible serde_json
+ /// input sources.
+ ///
+ /// Typically it is more convenient to use one of these methods instead:
+ ///
+ /// - Deserializer::from_str(...).into_iter()
+ /// - Deserializer::from_slice(...).into_iter()
+ /// - Deserializer::from_reader(...).into_iter()
+ pub fn new(read: R) -> Self {
+ let offset = read.byte_offset();
+ StreamDeserializer {
+ de: Deserializer::new(read),
+ offset,
+ failed: false,
+ output: PhantomData,
+ lifetime: PhantomData,
+ }
+ }
+
+ /// Returns the number of bytes so far deserialized into a successful `T`.
+ ///
+ /// If a stream deserializer returns an EOF error, new data can be joined to
+ /// `old_data[stream.byte_offset()..]` to try again.
+ ///
+ /// ```
+ /// let data = b"[0] [1] [";
+ ///
+ /// let de = serde_json::Deserializer::from_slice(data);
+ /// let mut stream = de.into_iter::<Vec<i32>>();
+ /// assert_eq!(0, stream.byte_offset());
+ ///
+ /// println!("{:?}", stream.next()); // [0]
+ /// assert_eq!(3, stream.byte_offset());
+ ///
+ /// println!("{:?}", stream.next()); // [1]
+ /// assert_eq!(7, stream.byte_offset());
+ ///
+ /// println!("{:?}", stream.next()); // error
+ /// assert_eq!(8, stream.byte_offset());
+ ///
+ /// // If err.is_eof(), can join the remaining data to new data and continue.
+ /// let remaining = &data[stream.byte_offset()..];
+ /// ```
+ ///
+ /// *Note:* In the future this method may be changed to return the number of
+ /// bytes so far deserialized into a successful T *or* syntactically valid
+ /// JSON skipped over due to a type error. See [serde-rs/json#70] for an
+ /// example illustrating this.
+ ///
+ /// [serde-rs/json#70]: https://github.com/serde-rs/json/issues/70
+ pub fn byte_offset(&self) -> usize {
+ self.offset
+ }
+
+ fn peek_end_of_value(&mut self) -> Result<()> {
+ match tri!(self.de.peek()) {
+ Some(b' ') | Some(b'\n') | Some(b'\t') | Some(b'\r') | Some(b'"') | Some(b'[')
+ | Some(b']') | Some(b'{') | Some(b'}') | Some(b',') | Some(b':') | None => Ok(()),
+ Some(_) => {
+ let position = self.de.read.peek_position();
+ Err(Error::syntax(
+ ErrorCode::TrailingCharacters,
+ position.line,
+ position.column,
+ ))
+ }
+ }
+ }
+}
+
+impl<'de, R, T> Iterator for StreamDeserializer<'de, R, T>
+where
+ R: Read<'de>,
+ T: de::Deserialize<'de>,
+{
+ type Item = Result<T>;
+
+ fn next(&mut self) -> Option<Result<T>> {
+ if R::should_early_return_if_failed && self.failed {
+ return None;
+ }
+
+ // skip whitespaces, if any
+ // this helps with trailing whitespaces, since whitespaces between
+ // values are handled for us.
+ match self.de.parse_whitespace() {
+ Ok(None) => {
+ self.offset = self.de.read.byte_offset();
+ None
+ }
+ Ok(Some(b)) => {
+ // If the value does not have a clear way to show the end of the value
+ // (like numbers, null, true etc.) we have to look for whitespace or
+ // the beginning of a self-delineated value.
+ let self_delineated_value = match b {
+ b'[' | b'"' | b'{' => true,
+ _ => false,
+ };
+ self.offset = self.de.read.byte_offset();
+ let result = de::Deserialize::deserialize(&mut self.de);
+
+ Some(match result {
+ Ok(value) => {
+ self.offset = self.de.read.byte_offset();
+ if self_delineated_value {
+ Ok(value)
+ } else {
+ self.peek_end_of_value().map(|_| value)
+ }
+ }
+ Err(e) => {
+ self.de.read.set_failed(&mut self.failed);
+ Err(e)
+ }
+ })
+ }
+ Err(e) => {
+ self.de.read.set_failed(&mut self.failed);
+ Some(Err(e))
+ }
+ }
+ }
+}
+
+impl<'de, R, T> FusedIterator for StreamDeserializer<'de, R, T>
+where
+ R: Read<'de> + Fused,
+ T: de::Deserialize<'de>,
+{
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+fn from_trait<'de, R, T>(read: R) -> Result<T>
+where
+ R: Read<'de>,
+ T: de::Deserialize<'de>,
+{
+ let mut de = Deserializer::new(read);
+ let value = tri!(de::Deserialize::deserialize(&mut de));
+
+ // Make sure the whole stream has been consumed.
+ tri!(de.end());
+ Ok(value)
+}
+
+/// Deserialize an instance of type `T` from an IO stream of JSON.
+///
+/// The content of the IO stream is deserialized directly from the stream
+/// without being buffered in memory by serde_json.
+///
+/// When reading from a source against which short reads are not efficient, such
+/// as a [`File`], you will want to apply your own buffering because serde_json
+/// will not buffer the input. See [`std::io::BufReader`].
+///
+/// It is expected that the input stream ends after the deserialized object.
+/// If the stream does not end, such as in the case of a persistent socket connection,
+/// this function will not return. It is possible instead to deserialize from a prefix of an input
+/// stream without looking for EOF by managing your own [`Deserializer`].
+///
+/// Note that counter to intuition, this function is usually slower than
+/// reading a file completely into memory and then applying [`from_str`]
+/// or [`from_slice`] on it. See [issue #160].
+///
+/// [`File`]: https://doc.rust-lang.org/std/fs/struct.File.html
+/// [`std::io::BufReader`]: https://doc.rust-lang.org/std/io/struct.BufReader.html
+/// [`from_str`]: ./fn.from_str.html
+/// [`from_slice`]: ./fn.from_slice.html
+/// [issue #160]: https://github.com/serde-rs/json/issues/160
+///
+/// # Example
+///
+/// Reading the contents of a file.
+///
+/// ```
+/// use serde::Deserialize;
+///
+/// use std::error::Error;
+/// use std::fs::File;
+/// use std::io::BufReader;
+/// use std::path::Path;
+///
+/// #[derive(Deserialize, Debug)]
+/// struct User {
+/// fingerprint: String,
+/// location: String,
+/// }
+///
+/// fn read_user_from_file<P: AsRef<Path>>(path: P) -> Result<User, Box<dyn Error>> {
+/// // Open the file in read-only mode with buffer.
+/// let file = File::open(path)?;
+/// let reader = BufReader::new(file);
+///
+/// // Read the JSON contents of the file as an instance of `User`.
+/// let u = serde_json::from_reader(reader)?;
+///
+/// // Return the `User`.
+/// Ok(u)
+/// }
+///
+/// fn main() {
+/// # }
+/// # fn fake_main() {
+/// let u = read_user_from_file("test.json").unwrap();
+/// println!("{:#?}", u);
+/// }
+/// ```
+///
+/// Reading from a persistent socket connection.
+///
+/// ```
+/// use serde::Deserialize;
+///
+/// use std::error::Error;
+/// use std::net::{TcpListener, TcpStream};
+///
+/// #[derive(Deserialize, Debug)]
+/// struct User {
+/// fingerprint: String,
+/// location: String,
+/// }
+///
+/// fn read_user_from_stream(tcp_stream: TcpStream) -> Result<User, Box<dyn Error>> {
+/// let mut de = serde_json::Deserializer::from_reader(tcp_stream);
+/// let u = User::deserialize(&mut de)?;
+///
+/// Ok(u)
+/// }
+///
+/// fn main() {
+/// # }
+/// # fn fake_main() {
+/// let listener = TcpListener::bind("127.0.0.1:4000").unwrap();
+///
+/// for stream in listener.incoming() {
+/// println!("{:#?}", read_user_from_stream(stream.unwrap()));
+/// }
+/// }
+/// ```
+///
+/// # Errors
+///
+/// This conversion can fail if the structure of the input does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the input
+/// contains something other than a JSON map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the JSON map or some number is too big to fit in the expected primitive
+/// type.
+#[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+pub fn from_reader<R, T>(rdr: R) -> Result<T>
+where
+ R: crate::io::Read,
+ T: de::DeserializeOwned,
+{
+ from_trait(read::IoRead::new(rdr))
+}
+
+/// Deserialize an instance of type `T` from bytes of JSON text.
+///
+/// # Example
+///
+/// ```
+/// use serde::Deserialize;
+///
+/// #[derive(Deserialize, Debug)]
+/// struct User {
+/// fingerprint: String,
+/// location: String,
+/// }
+///
+/// fn main() {
+/// // The type of `j` is `&[u8]`
+/// let j = b"
+/// {
+/// \"fingerprint\": \"0xF9BA143B95FF6D82\",
+/// \"location\": \"Menlo Park, CA\"
+/// }";
+///
+/// let u: User = serde_json::from_slice(j).unwrap();
+/// println!("{:#?}", u);
+/// }
+/// ```
+///
+/// # Errors
+///
+/// This conversion can fail if the structure of the input does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the input
+/// contains something other than a JSON map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the JSON map or some number is too big to fit in the expected primitive
+/// type.
+pub fn from_slice<'a, T>(v: &'a [u8]) -> Result<T>
+where
+ T: de::Deserialize<'a>,
+{
+ from_trait(read::SliceRead::new(v))
+}
+
+/// Deserialize an instance of type `T` from a string of JSON text.
+///
+/// # Example
+///
+/// ```
+/// use serde::Deserialize;
+///
+/// #[derive(Deserialize, Debug)]
+/// struct User {
+/// fingerprint: String,
+/// location: String,
+/// }
+///
+/// fn main() {
+/// // The type of `j` is `&str`
+/// let j = "
+/// {
+/// \"fingerprint\": \"0xF9BA143B95FF6D82\",
+/// \"location\": \"Menlo Park, CA\"
+/// }";
+///
+/// let u: User = serde_json::from_str(j).unwrap();
+/// println!("{:#?}", u);
+/// }
+/// ```
+///
+/// # Errors
+///
+/// This conversion can fail if the structure of the input does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the input
+/// contains something other than a JSON map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the JSON map or some number is too big to fit in the expected primitive
+/// type.
+pub fn from_str<'a, T>(s: &'a str) -> Result<T>
+where
+ T: de::Deserialize<'a>,
+{
+ from_trait(read::StrRead::new(s))
+}