Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 2279 insertions, 0 deletions

diff --git a/third_party/rust/bincode/src/config.rs b/third_party/rust/bincode/src/config.rs
new file mode 100644
index 0000000000..885dbc7f09
--- /dev/null
+++ b/third_party/rust/bincode/src/config.rs
@@ -0,0 +1,364 @@
+use super::internal::{Bounded, Infinite, SizeLimit};
+use byteorder::{BigEndian, ByteOrder, LittleEndian, NativeEndian};
+use de::read::BincodeRead;
+use error::Result;
+use serde;
+use std::io::{Read, Write};
+use std::marker::PhantomData;
+use {DeserializerAcceptor, SerializerAcceptor};
+
+use self::EndianOption::*;
+use self::LimitOption::*;
+
+struct DefaultOptions(Infinite);
+
+pub(crate) trait Options {
+    type Limit: SizeLimit + 'static;
+    type Endian: ByteOrder + 'static;
+
+    fn limit(&mut self) -> &mut Self::Limit;
+}
+
+pub(crate) trait OptionsExt: Options + Sized {
+    fn with_no_limit(self) -> WithOtherLimit<Self, Infinite> {
+        WithOtherLimit::new(self, Infinite)
+    }
+
+    fn with_limit(self, limit: u64) -> WithOtherLimit<Self, Bounded> {
+        WithOtherLimit::new(self, Bounded(limit))
+    }
+
+    fn with_little_endian(self) -> WithOtherEndian<Self, LittleEndian> {
+        WithOtherEndian::new(self)
+    }
+
+    fn with_big_endian(self) -> WithOtherEndian<Self, BigEndian> {
+        WithOtherEndian::new(self)
+    }
+
+    fn with_native_endian(self) -> WithOtherEndian<Self, NativeEndian> {
+        WithOtherEndian::new(self)
+    }
+}
+
+impl<'a, O: Options> Options for &'a mut O {
+    type Limit = O::Limit;
+    type Endian = O::Endian;
+
+    #[inline(always)]
+    fn limit(&mut self) -> &mut Self::Limit {
+        (*self).limit()
+    }
+}
+
+impl<T: Options> OptionsExt for T {}
+
+impl DefaultOptions {
+    fn new() -> DefaultOptions {
+        DefaultOptions(Infinite)
+    }
+}
+
+impl Options for DefaultOptions {
+    type Limit = Infinite;
+    type Endian = LittleEndian;
+
+    #[inline(always)]
+    fn limit(&mut self) -> &mut Infinite {
+        &mut self.0
+    }
+}
+
+#[derive(Clone, Copy)]
+enum LimitOption {
+    Unlimited,
+    Limited(u64),
+}
+
+#[derive(Clone, Copy)]
+enum EndianOption {
+    Big,
+    Little,
+    Native,
+}
+
+/// A configuration builder whose options Bincode will use
+/// while serializing and deserializing.
+///
+/// ### Options
+/// Endianness: The endianness with which multi-byte integers will be read/written.  *default: little endian*
+/// Limit: The maximum number of bytes that will be read/written in a bincode serialize/deserialize. *default: unlimited*
+///
+/// ### Byte Limit Details
+/// The purpose of byte-limiting is to prevent Denial-Of-Service attacks whereby malicious attackers get bincode
+/// deserialization to crash your process by allocating too much memory or keeping a connection open for too long.
+///
+/// When a byte limit is set, bincode will return `Err` on any deserialization that goes over the limit, or any
+/// serialization that goes over the limit.
+#[derive(Clone)]
+pub struct Config {
+    limit: LimitOption,
+    endian: EndianOption,
+}
+
+pub(crate) struct WithOtherLimit<O: Options, L: SizeLimit> {
+    _options: O,
+    pub(crate) new_limit: L,
+}
+
+pub(crate) struct WithOtherEndian<O: Options, E: ByteOrder> {
+    options: O,
+    _endian: PhantomData<E>,
+}
+
+impl<O: Options, L: SizeLimit> WithOtherLimit<O, L> {
+    #[inline(always)]
+    pub(crate) fn new(options: O, limit: L) -> WithOtherLimit<O, L> {
+        WithOtherLimit {
+            _options: options,
+            new_limit: limit,
+        }
+    }
+}
+
+impl<O: Options, E: ByteOrder> WithOtherEndian<O, E> {
+    #[inline(always)]
+    pub(crate) fn new(options: O) -> WithOtherEndian<O, E> {
+        WithOtherEndian {
+            options: options,
+            _endian: PhantomData,
+        }
+    }
+}
+
+impl<O: Options, E: ByteOrder + 'static> Options for WithOtherEndian<O, E> {
+    type Limit = O::Limit;
+    type Endian = E;
+
+    #[inline(always)]
+    fn limit(&mut self) -> &mut O::Limit {
+        self.options.limit()
+    }
+}
+
+impl<O: Options, L: SizeLimit + 'static> Options for WithOtherLimit<O, L> {
+    type Limit = L;
+    type Endian = O::Endian;
+
+    fn limit(&mut self) -> &mut L {
+        &mut self.new_limit
+    }
+}
+
+macro_rules! config_map {
+    ($self:expr, $opts:ident => $call:expr) => {
+        match ($self.limit, $self.endian) {
+            (Unlimited, Little) => {
+                let $opts = DefaultOptions::new().with_no_limit().with_little_endian();
+                $call
+            }
+            (Unlimited, Big) => {
+                let $opts = DefaultOptions::new().with_no_limit().with_big_endian();
+                $call
+            }
+            (Unlimited, Native) => {
+                let $opts = DefaultOptions::new().with_no_limit().with_native_endian();
+                $call
+            }
+
+            (Limited(l), Little) => {
+                let $opts = DefaultOptions::new().with_limit(l).with_little_endian();
+                $call
+            }
+            (Limited(l), Big) => {
+                let $opts = DefaultOptions::new().with_limit(l).with_big_endian();
+                $call
+            }
+            (Limited(l), Native) => {
+                let $opts = DefaultOptions::new().with_limit(l).with_native_endian();
+                $call
+            }
+        }
+    };
+}
+
+impl Config {
+    #[inline(always)]
+    pub(crate) fn new() -> Config {
+        Config {
+            limit: LimitOption::Unlimited,
+            endian: EndianOption::Little,
+        }
+    }
+
+    /// Sets the byte limit to be unlimited.
+    /// This is the default.
+    #[inline(always)]
+    pub fn no_limit(&mut self) -> &mut Self {
+        self.limit = LimitOption::Unlimited;
+        self
+    }
+
+    /// Sets the byte limit to `limit`.
+    #[inline(always)]
+    pub fn limit(&mut self, limit: u64) -> &mut Self {
+        self.limit = LimitOption::Limited(limit);
+        self
+    }
+
+    /// Sets the endianness to little-endian
+    /// This is the default.
+    #[inline(always)]
+    pub fn little_endian(&mut self) -> &mut Self {
+        self.endian = EndianOption::Little;
+        self
+    }
+
+    /// Sets the endianness to big-endian
+    #[inline(always)]
+    pub fn big_endian(&mut self) -> &mut Self {
+        self.endian = EndianOption::Big;
+        self
+    }
+
+    /// Sets the endianness to the the machine-native endianness
+    #[inline(always)]
+    pub fn native_endian(&mut self) -> &mut Self {
+        self.endian = EndianOption::Native;
+        self
+    }
+
+    /// Serializes a serializable object into a `Vec` of bytes using this configuration
+    #[inline(always)]
+    pub fn serialize<T: ?Sized + serde::Serialize>(&self, t: &T) -> Result<Vec<u8>> {
+        config_map!(self, opts => ::internal::serialize(t, opts))
+    }
+
+    /// Returns the size that an object would be if serialized using Bincode with this configuration
+    #[inline(always)]
+    pub fn serialized_size<T: ?Sized + serde::Serialize>(&self, t: &T) -> Result<u64> {
+        config_map!(self, opts => ::internal::serialized_size(t, opts))
+    }
+
+    /// Serializes an object directly into a `Writer` using this configuration
+    ///
+    /// If the serialization would take more bytes than allowed by the size limit, an error
+    /// is returned and *no bytes* will be written into the `Writer`
+    #[inline(always)]
+    pub fn serialize_into<W: Write, T: ?Sized + serde::Serialize>(
+        &self,
+        w: W,
+        t: &T,
+    ) -> Result<()> {
+        config_map!(self, opts => ::internal::serialize_into(w, t, opts))
+    }
+
+    /// Deserializes a slice of bytes into an instance of `T` using this configuration
+    #[inline(always)]
+    pub fn deserialize<'a, T: serde::Deserialize<'a>>(&self, bytes: &'a [u8]) -> Result<T> {
+        config_map!(self, opts => ::internal::deserialize(bytes, opts))
+    }
+
+    /// TODO: document
+    #[doc(hidden)]
+    #[inline(always)]
+    pub fn deserialize_in_place<'a, R, T>(&self, reader: R, place: &mut T) -> Result<()>
+    where
+        R: BincodeRead<'a>,
+        T: serde::de::Deserialize<'a>,
+    {
+        config_map!(self, opts => ::internal::deserialize_in_place(reader, opts, place))
+    }
+
+    /// Deserializes a slice of bytes with state `seed` using this configuration.
+    #[inline(always)]
+    pub fn deserialize_seed<'a, T: serde::de::DeserializeSeed<'a>>(
+        &self,
+        seed: T,
+        bytes: &'a [u8],
+    ) -> Result<T::Value> {
+        config_map!(self, opts => ::internal::deserialize_seed(seed, bytes, opts))
+    }
+
+    /// Deserializes an object directly from a `Read`er using this configuration
+    ///
+    /// If this returns an `Error`, `reader` may be in an invalid state.
+    #[inline(always)]
+    pub fn deserialize_from<R: Read, T: serde::de::DeserializeOwned>(
+        &self,
+        reader: R,
+    ) -> Result<T> {
+        config_map!(self, opts => ::internal::deserialize_from(reader, opts))
+    }
+
+    /// Deserializes an object directly from a `Read`er with state `seed` using this configuration
+    ///
+    /// If this returns an `Error`, `reader` may be in an invalid state.
+    #[inline(always)]
+    pub fn deserialize_from_seed<'a, R: Read, T: serde::de::DeserializeSeed<'a>>(
+        &self,
+        seed: T,
+        reader: R,
+    ) -> Result<T::Value> {
+        config_map!(self, opts => ::internal::deserialize_from_seed(seed, reader, opts))
+    }
+
+    /// Deserializes an object from a custom `BincodeRead`er using the default configuration.
+    /// It is highly recommended to use `deserialize_from` unless you need to implement
+    /// `BincodeRead` for performance reasons.
+    ///
+    /// If this returns an `Error`, `reader` may be in an invalid state.
+    #[inline(always)]
+    pub fn deserialize_from_custom<'a, R: BincodeRead<'a>, T: serde::de::DeserializeOwned>(
+        &self,
+        reader: R,
+    ) -> Result<T> {
+        config_map!(self, opts => ::internal::deserialize_from_custom(reader, opts))
+    }
+
+    /// Deserializes an object from a custom `BincodeRead`er with state `seed` using the default
+    /// configuration. It is highly recommended to use `deserialize_from` unless you need to
+    /// implement `BincodeRead` for performance reasons.
+    ///
+    /// If this returns an `Error`, `reader` may be in an invalid state.
+    #[inline(always)]
+    pub fn deserialize_from_custom_seed<
+        'a,
+        R: BincodeRead<'a>,
+        T: serde::de::DeserializeSeed<'a>,
+    >(
+        &self,
+        seed: T,
+        reader: R,
+    ) -> Result<T::Value> {
+        config_map!(self, opts => ::internal::deserialize_from_custom_seed(seed, reader, opts))
+    }
+
+    /// Executes the acceptor with a serde::Deserializer instance.
+    /// NOT A PART OF THE STABLE PUBLIC API
+    #[doc(hidden)]
+    pub fn with_deserializer<'a, A, R>(&self, reader: R, acceptor: A) -> A::Output
+    where
+        A: DeserializerAcceptor<'a>,
+        R: BincodeRead<'a>,
+    {
+        config_map!(self, opts => {
+            let mut deserializer = ::de::Deserializer::new(reader, opts);
+            acceptor.accept(&mut deserializer)
+        })
+    }
+
+    /// Executes the acceptor with a serde::Serializer instance.
+    /// NOT A PART OF THE STABLE PUBLIC API
+    #[doc(hidden)]
+    pub fn with_serializer<A, W>(&self, writer: W, acceptor: A) -> A::Output
+    where
+        A: SerializerAcceptor,
+        W: Write,
+    {
+        config_map!(self, opts => {
+            let mut serializer = ::ser::Serializer::new(writer, opts);
+            acceptor.accept(&mut serializer)
+        })
+    }
+}
diff --git a/third_party/rust/bincode/src/de/mod.rs b/third_party/rust/bincode/src/de/mod.rs
new file mode 100644
index 0000000000..00f672d36b
--- /dev/null
+++ b/third_party/rust/bincode/src/de/mod.rs
@@ -0,0 +1,465 @@
+use config::Options;
+use std::io::Read;
+
+use self::read::BincodeRead;
+use byteorder::ReadBytesExt;
+use internal::SizeLimit;
+use serde;
+use serde::de::Error as DeError;
+use serde::de::IntoDeserializer;
+use {Error, ErrorKind, Result};
+
+pub mod read;
+
+/// A Deserializer that reads bytes from a buffer.
+///
+/// This struct should rarely be used.
+/// In most cases, prefer the `deserialize_from` function.
+///
+/// The ByteOrder that is chosen will impact the endianness that
+/// is used to read integers out of the reader.
+///
+/// ```ignore
+/// let d = Deserializer::new(&mut some_reader, SizeLimit::new());
+/// serde::Deserialize::deserialize(&mut deserializer);
+/// let bytes_read = d.bytes_read();
+/// ```
+pub(crate) struct Deserializer<R, O: Options> {
+    reader: R,
+    options: O,
+}
+
+impl<'de, R: BincodeRead<'de>, O: Options> Deserializer<R, O> {
+    /// Creates a new Deserializer with a given `Read`er and a size_limit.
+    pub(crate) fn new(r: R, options: O) -> Deserializer<R, O> {
+        Deserializer {
+            reader: r,
+            options: options,
+        }
+    }
+
+    fn read_bytes(&mut self, count: u64) -> Result<()> {
+        self.options.limit().add(count)
+    }
+
+    fn read_type<T>(&mut self) -> Result<()> {
+        use std::mem::size_of;
+        self.read_bytes(size_of::<T>() as u64)
+    }
+
+    fn read_vec(&mut self) -> Result<Vec<u8>> {
+        let len: usize = try!(serde::Deserialize::deserialize(&mut *self));
+        self.read_bytes(len as u64)?;
+        self.reader.get_byte_buffer(len)
+    }
+
+    fn read_string(&mut self) -> Result<String> {
+        let vec = self.read_vec()?;
+        String::from_utf8(vec).map_err(|e| ErrorKind::InvalidUtf8Encoding(e.utf8_error()).into())
+    }
+}
+
+macro_rules! impl_nums {
+    ($ty:ty, $dser_method:ident, $visitor_method:ident, $reader_method:ident) => {
+        #[inline]
+        fn $dser_method<V>(self, visitor: V) -> Result<V::Value>
+            where V: serde::de::Visitor<'de>,
+        {
+            try!(self.read_type::<$ty>());
+            let value = try!(self.reader.$reader_method::<O::Endian>());
+            visitor.$visitor_method(value)
+        }
+    }
+}
+
+impl<'de, 'a, R, O> serde::Deserializer<'de> for &'a mut Deserializer<R, O>
+where
+    R: BincodeRead<'de>,
+    O: Options,
+{
+    type Error = Error;
+
+    #[inline]
+    fn deserialize_any<V>(self, _visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        Err(Box::new(ErrorKind::DeserializeAnyNotSupported))
+    }
+
+    fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let value: u8 = try!(serde::Deserialize::deserialize(self));
+        match value {
+            1 => visitor.visit_bool(true),
+            0 => visitor.visit_bool(false),
+            value => Err(ErrorKind::InvalidBoolEncoding(value).into()),
+        }
+    }
+
+    impl_nums!(u16, deserialize_u16, visit_u16, read_u16);
+    impl_nums!(u32, deserialize_u32, visit_u32, read_u32);
+    impl_nums!(u64, deserialize_u64, visit_u64, read_u64);
+    impl_nums!(i16, deserialize_i16, visit_i16, read_i16);
+    impl_nums!(i32, deserialize_i32, visit_i32, read_i32);
+    impl_nums!(i64, deserialize_i64, visit_i64, read_i64);
+    impl_nums!(f32, deserialize_f32, visit_f32, read_f32);
+    impl_nums!(f64, deserialize_f64, visit_f64, read_f64);
+
+    serde_if_integer128! {
+        impl_nums!(u128, deserialize_u128, visit_u128, read_u128);
+        impl_nums!(i128, deserialize_i128, visit_i128, read_i128);
+    }
+
+    #[inline]
+    fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        try!(self.read_type::<u8>());
+        visitor.visit_u8(try!(self.reader.read_u8()))
+    }
+
+    #[inline]
+    fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        try!(self.read_type::<i8>());
+        visitor.visit_i8(try!(self.reader.read_i8()))
+    }
+
+    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>,
+    {
+        use std::str;
+
+        let error = || ErrorKind::InvalidCharEncoding.into();
+
+        let mut buf = [0u8; 4];
+
+        // Look at the first byte to see how many bytes must be read
+        let _ = try!(self.reader.read_exact(&mut buf[..1]));
+        let width = utf8_char_width(buf[0]);
+        if width == 1 {
+            return visitor.visit_char(buf[0] as char);
+        }
+        if width == 0 {
+            return Err(error());
+        }
+
+        if self.reader.read_exact(&mut buf[1..width]).is_err() {
+            return Err(error());
+        }
+
+        let res = try!(
+            str::from_utf8(&buf[..width])
+                .ok()
+                .and_then(|s| s.chars().next())
+                .ok_or(error())
+        );
+        visitor.visit_char(res)
+    }
+
+    fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let len: usize = try!(serde::Deserialize::deserialize(&mut *self));
+        try!(self.read_bytes(len as u64));
+        self.reader.forward_read_str(len, visitor)
+    }
+
+    fn deserialize_string<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        visitor.visit_string(try!(self.read_string()))
+    }
+
+    fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let len: usize = try!(serde::Deserialize::deserialize(&mut *self));
+        try!(self.read_bytes(len as u64));
+        self.reader.forward_read_bytes(len, visitor)
+    }
+
+    fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        visitor.visit_byte_buf(try!(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>,
+    {
+        impl<'de, 'a, R: 'a, O> serde::de::EnumAccess<'de> for &'a mut Deserializer<R, O>
+        where
+            R: BincodeRead<'de>,
+            O: Options,
+        {
+            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 = try!(serde::de::Deserialize::deserialize(&mut *self));
+                let val: Result<_> = seed.deserialize(idx.into_deserializer());
+                Ok((try!(val), self))
+            }
+        }
+
+        visitor.visit_enum(self)
+    }
+
+    fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        struct Access<'a, R: Read + 'a, O: Options + 'a> {
+            deserializer: &'a mut Deserializer<R, O>,
+            len: usize,
+        }
+
+        impl<'de, 'a, 'b: 'a, R: BincodeRead<'de> + 'b, O: Options> serde::de::SeqAccess<'de>
+            for Access<'a, R, O>
+        {
+            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 = try!(serde::de::DeserializeSeed::deserialize(
+                        seed,
+                        &mut *self.deserializer,
+                    ));
+                    Ok(Some(value))
+                } else {
+                    Ok(None)
+                }
+            }
+
+            fn size_hint(&self) -> Option<usize> {
+                Some(self.len)
+            }
+        }
+
+        visitor.visit_seq(Access {
+            deserializer: self,
+            len: len,
+        })
+    }
+
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let value: u8 = try!(serde::de::Deserialize::deserialize(&mut *self));
+        match value {
+            0 => visitor.visit_none(),
+            1 => visitor.visit_some(&mut *self),
+            v => Err(ErrorKind::InvalidTagEncoding(v as usize).into()),
+        }
+    }
+
+    fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let len = try!(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>,
+    {
+        struct Access<'a, R: Read + 'a, O: Options + 'a> {
+            deserializer: &'a mut Deserializer<R, O>,
+            len: usize,
+        }
+
+        impl<'de, 'a, 'b: 'a, R: BincodeRead<'de> + 'b, O: Options> serde::de::MapAccess<'de>
+            for Access<'a, R, O>
+        {
+            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 = try!(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 = try!(serde::de::DeserializeSeed::deserialize(
+                    seed,
+                    &mut *self.deserializer,
+                ));
+                Ok(value)
+            }
+
+            fn size_hint(&self) -> Option<usize> {
+                Some(self.len)
+            }
+        }
+
+        let len = try!(serde::Deserialize::deserialize(&mut *self));
+
+        visitor.visit_map(Access {
+            deserializer: self,
+            len: 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>,
+    {
+        let message = "Bincode does not support Deserializer::deserialize_identifier";
+        Err(Error::custom(message))
+    }
+
+    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>,
+    {
+        let message = "Bincode does not support Deserializer::deserialize_ignored_any";
+        Err(Error::custom(message))
+    }
+
+    fn is_human_readable(&self) -> bool {
+        false
+    }
+}
+
+impl<'de, 'a, R, O> serde::de::VariantAccess<'de> for &'a mut Deserializer<R, O>
+where
+    R: BincodeRead<'de>,
+    O: Options,
+{
+    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)
+    }
+}
+static UTF8_CHAR_WIDTH: [u8; 256] = [
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, // 0x1F
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, // 0x3F
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, // 0x5F
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, // 0x7F
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, // 0x9F
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, // 0xBF
+    0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+    2, // 0xDF
+    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, // 0xEF
+    4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0xFF
+];
+
+// This function is a copy of core::str::utf8_char_width
+fn utf8_char_width(b: u8) -> usize {
+    UTF8_CHAR_WIDTH[b as usize] as usize
+}
diff --git a/third_party/rust/bincode/src/de/read.rs b/third_party/rust/bincode/src/de/read.rs
new file mode 100644
index 0000000000..ffc5ae2ac0
--- /dev/null
+++ b/third_party/rust/bincode/src/de/read.rs
@@ -0,0 +1,201 @@
+use error::Result;
+use serde;
+use std::{io, slice};
+
+/// An optional Read trait for advanced Bincode usage.
+///
+/// It is highly recommended to use bincode with `io::Read` or `&[u8]` before
+/// implementing a custom `BincodeRead`.
+pub trait BincodeRead<'storage>: io::Read {
+    /// Forwards reading `length` bytes of a string on to the serde reader.
+    fn forward_read_str<V>(&mut self, length: usize, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'storage>;
+
+    /// Return the first `length` bytes of the internal byte buffer.
+    fn get_byte_buffer(&mut self, length: usize) -> Result<Vec<u8>>;
+
+    /// Forwards reading `length` bytes on to the serde reader.
+    fn forward_read_bytes<V>(&mut self, length: usize, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'storage>;
+}
+
+/// A BincodeRead implementation for byte slices
+/// NOT A PART OF THE STABLE PUBLIC API
+#[doc(hidden)]
+pub struct SliceReader<'storage> {
+    slice: &'storage [u8],
+}
+
+/// A BincodeRead implementation for io::Readers
+/// NOT A PART OF THE STABLE PUBLIC API
+#[doc(hidden)]
+pub struct IoReader<R> {
+    reader: R,
+    temp_buffer: Vec<u8>,
+}
+
+impl<'storage> SliceReader<'storage> {
+    /// Constructs a slice reader
+    pub fn new(bytes: &'storage [u8]) -> SliceReader<'storage> {
+        SliceReader { slice: bytes }
+    }
+}
+
+impl<R> IoReader<R> {
+    /// Constructs an IoReadReader
+    pub fn new(r: R) -> IoReader<R> {
+        IoReader {
+            reader: r,
+            temp_buffer: vec![],
+        }
+    }
+}
+
+impl<'storage> io::Read for SliceReader<'storage> {
+    #[inline(always)]
+    fn read(&mut self, out: &mut [u8]) -> io::Result<usize> {
+        (&mut self.slice).read(out)
+    }
+    #[inline(always)]
+    fn read_exact(&mut self, out: &mut [u8]) -> io::Result<()> {
+        (&mut self.slice).read_exact(out)
+    }
+}
+
+impl<R: io::Read> io::Read for IoReader<R> {
+    #[inline(always)]
+    fn read(&mut self, out: &mut [u8]) -> io::Result<usize> {
+        self.reader.read(out)
+    }
+    #[inline(always)]
+    fn read_exact(&mut self, out: &mut [u8]) -> io::Result<()> {
+        self.reader.read_exact(out)
+    }
+}
+
+impl<'storage> SliceReader<'storage> {
+    #[inline(always)]
+    fn unexpected_eof() -> Box<::ErrorKind> {
+        return Box::new(::ErrorKind::Io(io::Error::new(
+            io::ErrorKind::UnexpectedEof,
+            "",
+        )));
+    }
+}
+
+impl<'storage> BincodeRead<'storage> for SliceReader<'storage> {
+    #[inline(always)]
+    fn forward_read_str<V>(&mut self, length: usize, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'storage>,
+    {
+        use ErrorKind;
+        if length > self.slice.len() {
+            return Err(SliceReader::unexpected_eof());
+        }
+
+        let string = match ::std::str::from_utf8(&self.slice[..length]) {
+            Ok(s) => s,
+            Err(e) => return Err(ErrorKind::InvalidUtf8Encoding(e).into()),
+        };
+        let r = visitor.visit_borrowed_str(string);
+        self.slice = &self.slice[length..];
+        r
+    }
+
+    #[inline(always)]
+    fn get_byte_buffer(&mut self, length: usize) -> Result<Vec<u8>> {
+        if length > self.slice.len() {
+            return Err(SliceReader::unexpected_eof());
+        }
+
+        let r = &self.slice[..length];
+        self.slice = &self.slice[length..];
+        Ok(r.to_vec())
+    }
+
+    #[inline(always)]
+    fn forward_read_bytes<V>(&mut self, length: usize, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'storage>,
+    {
+        if length > self.slice.len() {
+            return Err(SliceReader::unexpected_eof());
+        }
+
+        let r = visitor.visit_borrowed_bytes(&self.slice[..length]);
+        self.slice = &self.slice[length..];
+        r
+    }
+}
+
+impl<R> IoReader<R>
+where
+    R: io::Read,
+{
+    fn fill_buffer(&mut self, length: usize) -> Result<()> {
+        // We first reserve the space needed in our buffer.
+        let current_length = self.temp_buffer.len();
+        if length > current_length {
+            self.temp_buffer.reserve_exact(length - current_length);
+        }
+
+        // Then create a slice with the length as our desired length. This is
+        // safe as long as we only write (no reads) to this buffer, because
+        // `reserve_exact` above has allocated this space.
+        let buf = unsafe {
+            slice::from_raw_parts_mut(self.temp_buffer.as_mut_ptr(), length)
+        };
+
+        // This method is assumed to properly handle slices which include
+        // uninitialized bytes (as ours does). See discussion at the link below.
+        // https://github.com/servo/bincode/issues/260
+        self.reader.read_exact(buf)?;
+
+        // Only after `read_exact` successfully returns do we set the buffer
+        // length. By doing this after the call to `read_exact`, we can avoid
+        // exposing uninitialized memory in the case of `read_exact` returning
+        // an error.
+        unsafe {
+            self.temp_buffer.set_len(length);
+        }
+
+        Ok(())
+    }
+}
+
+impl<'a, R> BincodeRead<'a> for IoReader<R>
+where
+    R: io::Read,
+{
+    fn forward_read_str<V>(&mut self, length: usize, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'a>,
+    {
+        self.fill_buffer(length)?;
+
+        let string = match ::std::str::from_utf8(&self.temp_buffer[..]) {
+            Ok(s) => s,
+            Err(e) => return Err(::ErrorKind::InvalidUtf8Encoding(e).into()),
+        };
+
+        let r = visitor.visit_str(string);
+        r
+    }
+
+    fn get_byte_buffer(&mut self, length: usize) -> Result<Vec<u8>> {
+        self.fill_buffer(length)?;
+        Ok(::std::mem::replace(&mut self.temp_buffer, Vec::new()))
+    }
+
+    fn forward_read_bytes<V>(&mut self, length: usize, visitor: V) -> Result<V::Value>
+    where
+        V: serde::de::Visitor<'a>,
+    {
+        self.fill_buffer(length)?;
+        let r = visitor.visit_bytes(&self.temp_buffer[..]);
+        r
+    }
+}
diff --git a/third_party/rust/bincode/src/error.rs b/third_party/rust/bincode/src/error.rs
new file mode 100644
index 0000000000..1f52424c18
--- /dev/null
+++ b/third_party/rust/bincode/src/error.rs
@@ -0,0 +1,115 @@
+use std::error::Error as StdError;
+use std::io;
+use std::str::Utf8Error;
+use std::{error, fmt};
+
+use serde;
+
+/// The result of a serialization or deserialization operation.
+pub type Result<T> = ::std::result::Result<T, Error>;
+
+/// An error that can be produced during (de)serializing.
+pub type Error = Box<ErrorKind>;
+
+/// The kind of error that can be produced during a serialization or deserialization.
+#[derive(Debug)]
+pub enum ErrorKind {
+    /// If the error stems from the reader/writer that is being used
+    /// during (de)serialization, that error will be stored and returned here.
+    Io(io::Error),
+    /// Returned if the deserializer attempts to deserialize a string that is not valid utf8
+    InvalidUtf8Encoding(Utf8Error),
+    /// Returned if the deserializer attempts to deserialize a bool that was
+    /// not encoded as either a 1 or a 0
+    InvalidBoolEncoding(u8),
+    /// Returned if the deserializer attempts to deserialize a char that is not in the correct format.
+    InvalidCharEncoding,
+    /// Returned if the deserializer attempts to deserialize the tag of an enum that is
+    /// not in the expected ranges
+    InvalidTagEncoding(usize),
+    /// Serde has a deserialize_any method that lets the format hint to the
+    /// object which route to take in deserializing.
+    DeserializeAnyNotSupported,
+    /// If (de)serializing a message takes more than the provided size limit, this
+    /// error is returned.
+    SizeLimit,
+    /// Bincode can not encode sequences of unknown length (like iterators).
+    SequenceMustHaveLength,
+    /// A custom error message from Serde.
+    Custom(String),
+}
+
+impl StdError for ErrorKind {
+    fn description(&self) -> &str {
+        match *self {
+            ErrorKind::Io(ref err) => error::Error::description(err),
+            ErrorKind::InvalidUtf8Encoding(_) => "string is not valid utf8",
+            ErrorKind::InvalidBoolEncoding(_) => "invalid u8 while decoding bool",
+            ErrorKind::InvalidCharEncoding => "char is not valid",
+            ErrorKind::InvalidTagEncoding(_) => "tag for enum is not valid",
+            ErrorKind::SequenceMustHaveLength => {
+                "Bincode can only encode sequences and maps that have a knowable size ahead of time"
+            }
+            ErrorKind::DeserializeAnyNotSupported => {
+                "Bincode doesn't support serde::Deserializer::deserialize_any"
+            }
+            ErrorKind::SizeLimit => "the size limit has been reached",
+            ErrorKind::Custom(ref msg) => msg,
+        }
+    }
+
+    fn cause(&self) -> Option<&error::Error> {
+        match *self {
+            ErrorKind::Io(ref err) => Some(err),
+            ErrorKind::InvalidUtf8Encoding(_) => None,
+            ErrorKind::InvalidBoolEncoding(_) => None,
+            ErrorKind::InvalidCharEncoding => None,
+            ErrorKind::InvalidTagEncoding(_) => None,
+            ErrorKind::SequenceMustHaveLength => None,
+            ErrorKind::DeserializeAnyNotSupported => None,
+            ErrorKind::SizeLimit => None,
+            ErrorKind::Custom(_) => None,
+        }
+    }
+}
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Error {
+        ErrorKind::Io(err).into()
+    }
+}
+
+impl fmt::Display for ErrorKind {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            ErrorKind::Io(ref ioerr) => write!(fmt, "io error: {}", ioerr),
+            ErrorKind::InvalidUtf8Encoding(ref e) => write!(fmt, "{}: {}", self.description(), e),
+            ErrorKind::InvalidBoolEncoding(b) => {
+                write!(fmt, "{}, expected 0 or 1, found {}", self.description(), b)
+            }
+            ErrorKind::InvalidCharEncoding => write!(fmt, "{}", self.description()),
+            ErrorKind::InvalidTagEncoding(tag) => {
+                write!(fmt, "{}, found {}", self.description(), tag)
+            }
+            ErrorKind::SequenceMustHaveLength => write!(fmt, "{}", self.description()),
+            ErrorKind::SizeLimit => write!(fmt, "{}", self.description()),
+            ErrorKind::DeserializeAnyNotSupported => write!(
+                fmt,
+                "Bincode does not support the serde::Deserializer::deserialize_any method"
+            ),
+            ErrorKind::Custom(ref s) => s.fmt(fmt),
+        }
+    }
+}
+
+impl serde::de::Error for Error {
+    fn custom<T: fmt::Display>(desc: T) -> Error {
+        ErrorKind::Custom(desc.to_string()).into()
+    }
+}
+
+impl serde::ser::Error for Error {
+    fn custom<T: fmt::Display>(msg: T) -> Self {
+        ErrorKind::Custom(msg.to_string()).into()
+    }
+}
diff --git a/third_party/rust/bincode/src/internal.rs b/third_party/rust/bincode/src/internal.rs
new file mode 100644
index 0000000000..968950a312
--- /dev/null
+++ b/third_party/rust/bincode/src/internal.rs
@@ -0,0 +1,191 @@
+use serde;
+use std::io::{Read, Write};
+use std::marker::PhantomData;
+
+use config::{Options, OptionsExt};
+use de::read::BincodeRead;
+use {ErrorKind, Result};
+
+#[derive(Clone)]
+struct CountSize<L: SizeLimit> {
+    total: u64,
+    other_limit: L,
+}
+
+pub(crate) fn serialize_into<W, T: ?Sized, O>(writer: W, value: &T, mut options: O) -> Result<()>
+where
+    W: Write,
+    T: serde::Serialize,
+    O: Options,
+{
+    if options.limit().limit().is_some() {
+        // "compute" the size for the side-effect
+        // of returning Err if the bound was reached.
+        serialized_size(value, &mut options)?;
+    }
+
+    let mut serializer = ::ser::Serializer::<_, O>::new(writer, options);
+    serde::Serialize::serialize(value, &mut serializer)
+}
+
+pub(crate) fn serialize<T: ?Sized, O>(value: &T, mut options: O) -> Result<Vec<u8>>
+where
+    T: serde::Serialize,
+    O: Options,
+{
+    let mut writer = {
+        let actual_size = serialized_size(value, &mut options)?;
+        Vec::with_capacity(actual_size as usize)
+    };
+
+    serialize_into(&mut writer, value, options.with_no_limit())?;
+    Ok(writer)
+}
+
+impl<L: SizeLimit> SizeLimit for CountSize<L> {
+    fn add(&mut self, c: u64) -> Result<()> {
+        self.other_limit.add(c)?;
+        self.total += c;
+        Ok(())
+    }
+
+    fn limit(&self) -> Option<u64> {
+        unreachable!();
+    }
+}
+
+pub(crate) fn serialized_size<T: ?Sized, O: Options>(value: &T, mut options: O) -> Result<u64>
+where
+    T: serde::Serialize,
+{
+    let old_limiter = options.limit().clone();
+    let mut size_counter = ::ser::SizeChecker {
+        options: ::config::WithOtherLimit::new(
+            options,
+            CountSize {
+                total: 0,
+                other_limit: old_limiter,
+            },
+        ),
+    };
+
+    let result = value.serialize(&mut size_counter);
+    result.map(|_| size_counter.options.new_limit.total)
+}
+
+pub(crate) fn deserialize_from<R, T, O>(reader: R, options: O) -> Result<T>
+where
+    R: Read,
+    T: serde::de::DeserializeOwned,
+    O: Options,
+{
+    deserialize_from_seed(PhantomData, reader, options)
+}
+
+pub(crate) fn deserialize_from_seed<'a, R, T, O>(seed: T, reader: R, options: O) -> Result<T::Value>
+where
+    R: Read,
+    T: serde::de::DeserializeSeed<'a>,
+    O: Options,
+{
+    let reader = ::de::read::IoReader::new(reader);
+    deserialize_from_custom_seed(seed, reader, options)
+}
+
+pub(crate) fn deserialize_from_custom<'a, R, T, O>(reader: R, options: O) -> Result<T>
+where
+    R: BincodeRead<'a>,
+    T: serde::de::DeserializeOwned,
+    O: Options,
+{
+    deserialize_from_custom_seed(PhantomData, reader, options)
+}
+
+pub(crate) fn deserialize_from_custom_seed<'a, R, T, O>(
+    seed: T,
+    reader: R,
+    options: O,
+) -> Result<T::Value>
+where
+    R: BincodeRead<'a>,
+    T: serde::de::DeserializeSeed<'a>,
+    O: Options,
+{
+    let mut deserializer = ::de::Deserializer::<_, O>::new(reader, options);
+    seed.deserialize(&mut deserializer)
+}
+
+pub(crate) fn deserialize_in_place<'a, R, T, O>(reader: R, options: O, place: &mut T) -> Result<()>
+where
+    R: BincodeRead<'a>,
+    T: serde::de::Deserialize<'a>,
+    O: Options,
+{
+    let mut deserializer = ::de::Deserializer::<_, _>::new(reader, options);
+    serde::Deserialize::deserialize_in_place(&mut deserializer, place)
+}
+
+pub(crate) fn deserialize<'a, T, O>(bytes: &'a [u8], options: O) -> Result<T>
+where
+    T: serde::de::Deserialize<'a>,
+    O: Options,
+{
+    deserialize_seed(PhantomData, bytes, options)
+}
+
+pub(crate) fn deserialize_seed<'a, T, O>(seed: T, bytes: &'a [u8], options: O) -> Result<T::Value>
+where
+    T: serde::de::DeserializeSeed<'a>,
+    O: Options,
+{
+    let reader = ::de::read::SliceReader::new(bytes);
+    let options = ::config::WithOtherLimit::new(options, Infinite);
+    deserialize_from_custom_seed(seed, reader, options)
+}
+
+pub(crate) trait SizeLimit: Clone {
+    /// Tells the SizeLimit that a certain number of bytes has been
+    /// read or written.  Returns Err if the limit has been exceeded.
+    fn add(&mut self, n: u64) -> Result<()>;
+    /// Returns the hard limit (if one exists)
+    fn limit(&self) -> Option<u64>;
+}
+
+/// A SizeLimit that restricts serialized or deserialized messages from
+/// exceeding a certain byte length.
+#[derive(Copy, Clone)]
+pub struct Bounded(pub u64);
+
+/// A SizeLimit without a limit!
+/// Use this if you don't care about the size of encoded or decoded messages.
+#[derive(Copy, Clone)]
+pub struct Infinite;
+
+impl SizeLimit for Bounded {
+    #[inline(always)]
+    fn add(&mut self, n: u64) -> Result<()> {
+        if self.0 >= n {
+            self.0 -= n;
+            Ok(())
+        } else {
+            Err(Box::new(ErrorKind::SizeLimit))
+        }
+    }
+
+    #[inline(always)]
+    fn limit(&self) -> Option<u64> {
+        Some(self.0)
+    }
+}
+
+impl SizeLimit for Infinite {
+    #[inline(always)]
+    fn add(&mut self, _: u64) -> Result<()> {
+        Ok(())
+    }
+
+    #[inline(always)]
+    fn limit(&self) -> Option<u64> {
+        None
+    }
+}
diff --git a/third_party/rust/bincode/src/lib.rs b/third_party/rust/bincode/src/lib.rs
new file mode 100644
index 0000000000..594b69d741
--- /dev/null
+++ b/third_party/rust/bincode/src/lib.rs
@@ -0,0 +1,173 @@
+#![deny(missing_docs)]
+
+//! Bincode is a crate for encoding and decoding using a tiny binary
+//! serialization strategy.  Using it, you can easily go from having
+//! an object in memory, quickly serialize it to bytes, and then
+//! deserialize it back just as fast!
+//!
+//! ### Using Basic Functions
+//!
+//! ```edition2018
+//! fn main() {
+//!     // The object that we will serialize.
+//!     let target: Option<String>  = Some("hello world".to_string());
+//!
+//!     let encoded: Vec<u8> = bincode::serialize(&target).unwrap();
+//!     let decoded: Option<String> = bincode::deserialize(&encoded[..]).unwrap();
+//!     assert_eq!(target, decoded);
+//! }
+//! ```
+//!
+//! ### 128bit numbers
+//!
+//! Support for `i128` and `u128` is automatically enabled on Rust toolchains
+//! greater than or equal to `1.26.0` and disabled for targets which do not support it
+
+#![doc(html_root_url = "https://docs.rs/bincode/1.2.1")]
+#![crate_name = "bincode"]
+#![crate_type = "rlib"]
+#![crate_type = "dylib"]
+
+extern crate byteorder;
+#[macro_use]
+extern crate serde;
+
+mod config;
+mod de;
+mod error;
+mod internal;
+mod ser;
+
+pub use config::Config;
+pub use de::read::{BincodeRead, IoReader, SliceReader};
+pub use error::{Error, ErrorKind, Result};
+
+/// An object that implements this trait can be passed a
+/// serde::Deserializer without knowing its concrete type.
+///
+/// This trait should be used only for `with_deserializer` functions.
+#[doc(hidden)]
+pub trait DeserializerAcceptor<'a> {
+    /// The return type for the accept method
+    type Output;
+    /// Accept a serde::Deserializer and do whatever you want with it.
+    fn accept<T: serde::Deserializer<'a>>(self, T) -> Self::Output;
+}
+
+/// An object that implements this trait can be passed a
+/// serde::Serializer without knowing its concrete type.
+///
+/// This trait should be used only for `with_serializer` functions.
+#[doc(hidden)]
+pub trait SerializerAcceptor {
+    /// The return type for the accept method
+    type Output;
+    /// Accept a serde::Serializer and do whatever you want with it.
+    fn accept<T: serde::Serializer>(self, T) -> Self::Output;
+}
+
+/// Get a default configuration object.
+///
+/// ### Default Configuration:
+///
+/// | Byte limit | Endianness |
+/// |------------|------------|
+/// | Unlimited  | Little     |
+#[inline(always)]
+pub fn config() -> Config {
+    Config::new()
+}
+
+/// Serializes an object directly into a `Writer` using the default configuration.
+///
+/// If the serialization would take more bytes than allowed by the size limit, an error
+/// is returned and *no bytes* will be written into the `Writer`.
+pub fn serialize_into<W, T: ?Sized>(writer: W, value: &T) -> Result<()>
+where
+    W: std::io::Write,
+    T: serde::Serialize,
+{
+    config().serialize_into(writer, value)
+}
+
+/// Serializes a serializable object into a `Vec` of bytes using the default configuration.
+pub fn serialize<T: ?Sized>(value: &T) -> Result<Vec<u8>>
+where
+    T: serde::Serialize,
+{
+    config().serialize(value)
+}
+
+/// Deserializes an object directly from a `Read`er using the default configuration.
+///
+/// If this returns an `Error`, `reader` may be in an invalid state.
+pub fn deserialize_from<R, T>(reader: R) -> Result<T>
+where
+    R: std::io::Read,
+    T: serde::de::DeserializeOwned,
+{
+    config().deserialize_from(reader)
+}
+
+/// Deserializes an object from a custom `BincodeRead`er using the default configuration.
+/// It is highly recommended to use `deserialize_from` unless you need to implement
+/// `BincodeRead` for performance reasons.
+///
+/// If this returns an `Error`, `reader` may be in an invalid state.
+pub fn deserialize_from_custom<'a, R, T>(reader: R) -> Result<T>
+where
+    R: de::read::BincodeRead<'a>,
+    T: serde::de::DeserializeOwned,
+{
+    config().deserialize_from_custom(reader)
+}
+
+/// Only use this if you know what you're doing.
+///
+/// This is part of the public API.
+#[doc(hidden)]
+pub fn deserialize_in_place<'a, R, T>(reader: R, place: &mut T) -> Result<()>
+where
+    T: serde::de::Deserialize<'a>,
+    R: BincodeRead<'a>,
+{
+    config().deserialize_in_place(reader, place)
+}
+
+/// Deserializes a slice of bytes into an instance of `T` using the default configuration.
+pub fn deserialize<'a, T>(bytes: &'a [u8]) -> Result<T>
+where
+    T: serde::de::Deserialize<'a>,
+{
+    config().deserialize(bytes)
+}
+
+/// Returns the size that an object would be if serialized using Bincode with the default configuration.
+pub fn serialized_size<T: ?Sized>(value: &T) -> Result<u64>
+where
+    T: serde::Serialize,
+{
+    config().serialized_size(value)
+}
+
+/// Executes the acceptor with a serde::Deserializer instance.
+/// NOT A PART OF THE STABLE PUBLIC API
+#[doc(hidden)]
+pub fn with_deserializer<'a, A, R>(reader: R, acceptor: A) -> A::Output
+where
+    A: DeserializerAcceptor<'a>,
+    R: BincodeRead<'a>,
+{
+    config().with_deserializer(reader, acceptor)
+}
+
+/// Executes the acceptor with a serde::Serializer instance.
+/// NOT A PART OF THE STABLE PUBLIC API
+#[doc(hidden)]
+pub fn with_serializer<A, W>(writer: W, acceptor: A) -> A::Output
+where
+    A: SerializerAcceptor,
+    W: std::io::Write,
+{
+    config().with_serializer(writer, acceptor)
+}
diff --git a/third_party/rust/bincode/src/ser/mod.rs b/third_party/rust/bincode/src/ser/mod.rs
new file mode 100644
index 0000000000..737c80d129
--- /dev/null
+++ b/third_party/rust/bincode/src/ser/mod.rs
@@ -0,0 +1,770 @@
+use std::io::Write;
+use std::u32;
+
+use serde;
+
+use byteorder::WriteBytesExt;
+
+use super::internal::SizeLimit;
+use super::{Error, ErrorKind, Result};
+use config::Options;
+
+/// An Serializer that encodes values directly into a Writer.
+///
+/// The specified byte-order will impact the endianness that is
+/// used during the encoding.
+///
+/// This struct should not be used often.
+/// For most cases, prefer the `encode_into` function.
+pub(crate) struct Serializer<W, O: Options> {
+    writer: W,
+    _options: O,
+}
+
+impl<W: Write, O: Options> Serializer<W, O> {
+    /// Creates a new Serializer with the given `Write`r.
+    pub fn new(w: W, options: O) -> Serializer<W, O> {
+        Serializer {
+            writer: w,
+            _options: options,
+        }
+    }
+}
+
+impl<'a, W: Write, O: Options> serde::Serializer for &'a mut Serializer<W, O> {
+    type Ok = ();
+    type Error = Error;
+    type SerializeSeq = Compound<'a, W, O>;
+    type SerializeTuple = Compound<'a, W, O>;
+    type SerializeTupleStruct = Compound<'a, W, O>;
+    type SerializeTupleVariant = Compound<'a, W, O>;
+    type SerializeMap = Compound<'a, W, O>;
+    type SerializeStruct = Compound<'a, W, O>;
+    type SerializeStructVariant = Compound<'a, W, O>;
+
+    fn serialize_unit(self) -> Result<()> {
+        Ok(())
+    }
+
+    fn serialize_unit_struct(self, _: &'static str) -> Result<()> {
+        Ok(())
+    }
+
+    fn serialize_bool(self, v: bool) -> Result<()> {
+        self.writer
+            .write_u8(if v { 1 } else { 0 })
+            .map_err(Into::into)
+    }
+
+    fn serialize_u8(self, v: u8) -> Result<()> {
+        self.writer.write_u8(v).map_err(Into::into)
+    }
+
+    fn serialize_u16(self, v: u16) -> Result<()> {
+        self.writer.write_u16::<O::Endian>(v).map_err(Into::into)
+    }
+
+    fn serialize_u32(self, v: u32) -> Result<()> {
+        self.writer.write_u32::<O::Endian>(v).map_err(Into::into)
+    }
+
+    fn serialize_u64(self, v: u64) -> Result<()> {
+        self.writer.write_u64::<O::Endian>(v).map_err(Into::into)
+    }
+
+    fn serialize_i8(self, v: i8) -> Result<()> {
+        self.writer.write_i8(v).map_err(Into::into)
+    }
+
+    fn serialize_i16(self, v: i16) -> Result<()> {
+        self.writer.write_i16::<O::Endian>(v).map_err(Into::into)
+    }
+
+    fn serialize_i32(self, v: i32) -> Result<()> {
+        self.writer.write_i32::<O::Endian>(v).map_err(Into::into)
+    }
+
+    fn serialize_i64(self, v: i64) -> Result<()> {
+        self.writer.write_i64::<O::Endian>(v).map_err(Into::into)
+    }
+
+    serde_if_integer128! {
+        fn serialize_u128(self, v: u128) -> Result<()> {
+            self.writer.write_u128::<O::Endian>(v).map_err(Into::into)
+        }
+
+        fn serialize_i128(self, v: i128) -> Result<()> {
+            self.writer.write_i128::<O::Endian>(v).map_err(Into::into)
+        }
+    }
+
+    fn serialize_f32(self, v: f32) -> Result<()> {
+        self.writer.write_f32::<O::Endian>(v).map_err(Into::into)
+    }
+
+    fn serialize_f64(self, v: f64) -> Result<()> {
+        self.writer.write_f64::<O::Endian>(v).map_err(Into::into)
+    }
+
+    fn serialize_str(self, v: &str) -> Result<()> {
+        try!(self.serialize_u64(v.len() as u64));
+        self.writer.write_all(v.as_bytes()).map_err(Into::into)
+    }
+
+    fn serialize_char(self, c: char) -> Result<()> {
+        self.writer
+            .write_all(encode_utf8(c).as_slice())
+            .map_err(Into::into)
+    }
+
+    fn serialize_bytes(self, v: &[u8]) -> Result<()> {
+        try!(self.serialize_u64(v.len() as u64));
+        self.writer.write_all(v).map_err(Into::into)
+    }
+
+    fn serialize_none(self) -> Result<()> {
+        self.writer.write_u8(0).map_err(Into::into)
+    }
+
+    fn serialize_some<T: ?Sized>(self, v: &T) -> Result<()>
+    where
+        T: serde::Serialize,
+    {
+        try!(self.writer.write_u8(1));
+        v.serialize(self)
+    }
+
+    fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
+        let len = try!(len.ok_or(ErrorKind::SequenceMustHaveLength));
+        try!(self.serialize_u64(len as u64));
+        Ok(Compound { ser: self })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple> {
+        Ok(Compound { ser: self })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleStruct> {
+        Ok(Compound { ser: self })
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleVariant> {
+        try!(self.serialize_u32(variant_index));
+        Ok(Compound { ser: self })
+    }
+
+    fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap> {
+        let len = try!(len.ok_or(ErrorKind::SequenceMustHaveLength));
+        try!(self.serialize_u64(len as u64));
+        Ok(Compound { ser: self })
+    }
+
+    fn serialize_struct(self, _name: &'static str, _len: usize) -> Result<Self::SerializeStruct> {
+        Ok(Compound { ser: self })
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStructVariant> {
+        try!(self.serialize_u32(variant_index));
+        Ok(Compound { ser: self })
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _name: &'static str,
+        variant_index: u32,
+        _variant: &'static str,
+        value: &T,
+    ) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        try!(self.serialize_u32(variant_index));
+        value.serialize(self)
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        variant_index: u32,
+        _variant: &'static str,
+    ) -> Result<()> {
+        self.serialize_u32(variant_index)
+    }
+
+    fn is_human_readable(&self) -> bool {
+        false
+    }
+}
+
+pub(crate) struct SizeChecker<O: Options> {
+    pub options: O,
+}
+
+impl<O: Options> SizeChecker<O> {
+    pub fn new(options: O) -> SizeChecker<O> {
+        SizeChecker { options: options }
+    }
+
+    fn add_raw(&mut self, size: u64) -> Result<()> {
+        self.options.limit().add(size)
+    }
+
+    fn add_value<T>(&mut self, t: T) -> Result<()> {
+        use std::mem::size_of_val;
+        self.add_raw(size_of_val(&t) as u64)
+    }
+}
+
+impl<'a, O: Options> serde::Serializer for &'a mut SizeChecker<O> {
+    type Ok = ();
+    type Error = Error;
+    type SerializeSeq = SizeCompound<'a, O>;
+    type SerializeTuple = SizeCompound<'a, O>;
+    type SerializeTupleStruct = SizeCompound<'a, O>;
+    type SerializeTupleVariant = SizeCompound<'a, O>;
+    type SerializeMap = SizeCompound<'a, O>;
+    type SerializeStruct = SizeCompound<'a, O>;
+    type SerializeStructVariant = SizeCompound<'a, O>;
+
+    fn serialize_unit(self) -> Result<()> {
+        Ok(())
+    }
+
+    fn serialize_unit_struct(self, _: &'static str) -> Result<()> {
+        Ok(())
+    }
+
+    fn serialize_bool(self, _: bool) -> Result<()> {
+        self.add_value(0 as u8)
+    }
+
+    fn serialize_u8(self, v: u8) -> Result<()> {
+        self.add_value(v)
+    }
+
+    fn serialize_u16(self, v: u16) -> Result<()> {
+        self.add_value(v)
+    }
+
+    fn serialize_u32(self, v: u32) -> Result<()> {
+        self.add_value(v)
+    }
+
+    fn serialize_u64(self, v: u64) -> Result<()> {
+        self.add_value(v)
+    }
+
+    fn serialize_i8(self, v: i8) -> Result<()> {
+        self.add_value(v)
+    }
+
+    fn serialize_i16(self, v: i16) -> Result<()> {
+        self.add_value(v)
+    }
+
+    fn serialize_i32(self, v: i32) -> Result<()> {
+        self.add_value(v)
+    }
+
+    fn serialize_i64(self, v: i64) -> Result<()> {
+        self.add_value(v)
+    }
+
+    serde_if_integer128! {
+        fn serialize_u128(self, v: u128) -> Result<()> {
+            self.add_value(v)
+        }
+
+        fn serialize_i128(self, v: i128) -> Result<()> {
+            self.add_value(v)
+        }
+    }
+
+    fn serialize_f32(self, v: f32) -> Result<()> {
+        self.add_value(v)
+    }
+
+    fn serialize_f64(self, v: f64) -> Result<()> {
+        self.add_value(v)
+    }
+
+    fn serialize_str(self, v: &str) -> Result<()> {
+        try!(self.add_value(0 as u64));
+        self.add_raw(v.len() as u64)
+    }
+
+    fn serialize_char(self, c: char) -> Result<()> {
+        self.add_raw(encode_utf8(c).as_slice().len() as u64)
+    }
+
+    fn serialize_bytes(self, v: &[u8]) -> Result<()> {
+        try!(self.add_value(0 as u64));
+        self.add_raw(v.len() as u64)
+    }
+
+    fn serialize_none(self) -> Result<()> {
+        self.add_value(0 as u8)
+    }
+
+    fn serialize_some<T: ?Sized>(self, v: &T) -> Result<()>
+    where
+        T: serde::Serialize,
+    {
+        try!(self.add_value(1 as u8));
+        v.serialize(self)
+    }
+
+    fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
+        let len = try!(len.ok_or(ErrorKind::SequenceMustHaveLength));
+
+        try!(self.serialize_u64(len as u64));
+        Ok(SizeCompound { ser: self })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple> {
+        Ok(SizeCompound { ser: self })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleStruct> {
+        Ok(SizeCompound { ser: self })
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleVariant> {
+        try!(self.add_value(variant_index));
+        Ok(SizeCompound { ser: self })
+    }
+
+    fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap> {
+        let len = try!(len.ok_or(ErrorKind::SequenceMustHaveLength));
+
+        try!(self.serialize_u64(len as u64));
+        Ok(SizeCompound { ser: self })
+    }
+
+    fn serialize_struct(self, _name: &'static str, _len: usize) -> Result<Self::SerializeStruct> {
+        Ok(SizeCompound { ser: self })
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStructVariant> {
+        try!(self.add_value(variant_index));
+        Ok(SizeCompound { ser: self })
+    }
+
+    fn serialize_newtype_struct<V: serde::Serialize + ?Sized>(
+        self,
+        _name: &'static str,
+        v: &V,
+    ) -> Result<()> {
+        v.serialize(self)
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        variant_index: u32,
+        _variant: &'static str,
+    ) -> Result<()> {
+        self.add_value(variant_index)
+    }
+
+    fn serialize_newtype_variant<V: serde::Serialize + ?Sized>(
+        self,
+        _name: &'static str,
+        variant_index: u32,
+        _variant: &'static str,
+        value: &V,
+    ) -> Result<()> {
+        try!(self.add_value(variant_index));
+        value.serialize(self)
+    }
+
+    fn is_human_readable(&self) -> bool {
+        false
+    }
+}
+
+pub(crate) struct Compound<'a, W: 'a, O: Options + 'a> {
+    ser: &'a mut Serializer<W, O>,
+}
+
+impl<'a, W, O> serde::ser::SerializeSeq for Compound<'a, W, O>
+where
+    W: Write,
+    O: Options,
+{
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, W, O> serde::ser::SerializeTuple for Compound<'a, W, O>
+where
+    W: Write,
+    O: Options,
+{
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, W, O> serde::ser::SerializeTupleStruct for Compound<'a, W, O>
+where
+    W: Write,
+    O: Options,
+{
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, W, O> serde::ser::SerializeTupleVariant for Compound<'a, W, O>
+where
+    W: Write,
+    O: Options,
+{
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, W, O> serde::ser::SerializeMap for Compound<'a, W, O>
+where
+    W: Write,
+    O: Options,
+{
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_key<K: ?Sized>(&mut self, value: &K) -> Result<()>
+    where
+        K: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn serialize_value<V: ?Sized>(&mut self, value: &V) -> Result<()>
+    where
+        V: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, W, O> serde::ser::SerializeStruct for Compound<'a, W, O>
+where
+    W: Write,
+    O: Options,
+{
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_field<T: ?Sized>(&mut self, _key: &'static str, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, W, O> serde::ser::SerializeStructVariant for Compound<'a, W, O>
+where
+    W: Write,
+    O: Options,
+{
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_field<T: ?Sized>(&mut self, _key: &'static str, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+pub(crate) struct SizeCompound<'a, S: Options + 'a> {
+    ser: &'a mut SizeChecker<S>,
+}
+
+impl<'a, O: Options> serde::ser::SerializeSeq for SizeCompound<'a, O> {
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, O: Options> serde::ser::SerializeTuple for SizeCompound<'a, O> {
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, O: Options> serde::ser::SerializeTupleStruct for SizeCompound<'a, O> {
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, O: Options> serde::ser::SerializeTupleVariant for SizeCompound<'a, O> {
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, O: Options + 'a> serde::ser::SerializeMap for SizeCompound<'a, O> {
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_key<K: ?Sized>(&mut self, value: &K) -> Result<()>
+    where
+        K: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn serialize_value<V: ?Sized>(&mut self, value: &V) -> Result<()>
+    where
+        V: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, O: Options> serde::ser::SerializeStruct for SizeCompound<'a, O> {
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_field<T: ?Sized>(&mut self, _key: &'static str, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a, O: Options> serde::ser::SerializeStructVariant for SizeCompound<'a, O> {
+    type Ok = ();
+    type Error = Error;
+
+    #[inline]
+    fn serialize_field<T: ?Sized>(&mut self, _key: &'static str, value: &T) -> Result<()>
+    where
+        T: serde::ser::Serialize,
+    {
+        value.serialize(&mut *self.ser)
+    }
+
+    #[inline]
+    fn end(self) -> Result<()> {
+        Ok(())
+    }
+}
+const TAG_CONT: u8 = 0b1000_0000;
+const TAG_TWO_B: u8 = 0b1100_0000;
+const TAG_THREE_B: u8 = 0b1110_0000;
+const TAG_FOUR_B: u8 = 0b1111_0000;
+const MAX_ONE_B: u32 = 0x80;
+const MAX_TWO_B: u32 = 0x800;
+const MAX_THREE_B: u32 = 0x10000;
+
+fn encode_utf8(c: char) -> EncodeUtf8 {
+    let code = c as u32;
+    let mut buf = [0; 4];
+    let pos = if code < MAX_ONE_B {
+        buf[3] = code as u8;
+        3
+    } else if code < MAX_TWO_B {
+        buf[2] = (code >> 6 & 0x1F) as u8 | TAG_TWO_B;
+        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
+        2
+    } else if code < MAX_THREE_B {
+        buf[1] = (code >> 12 & 0x0F) as u8 | TAG_THREE_B;
+        buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT;
+        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
+        1
+    } else {
+        buf[0] = (code >> 18 & 0x07) as u8 | TAG_FOUR_B;
+        buf[1] = (code >> 12 & 0x3F) as u8 | TAG_CONT;
+        buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT;
+        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
+        0
+    };
+    EncodeUtf8 { buf: buf, pos: pos }
+}
+
+struct EncodeUtf8 {
+    buf: [u8; 4],
+    pos: usize,
+}
+
+impl EncodeUtf8 {
+    fn as_slice(&self) -> &[u8] {
+        &self.buf[self.pos..]
+    }
+}