sonic-rs 0.1.3

// The code is cloned from [serde_json](https://github.com/serde-rs/json) and modified necessary parts.

use crate::error::Error;
use core::fmt::{self, Debug, Display};
use core::mem;
use serde::de::value::BorrowedStrDeserializer;
use serde::de::{
    self, Deserialize, DeserializeSeed, Deserializer, IntoDeserializer, MapAccess, Unexpected,
    Visitor,
};
use serde::forward_to_deserialize_any;
use serde::ser::{Serialize, SerializeStruct, Serializer};
use std::borrow::ToOwned;
use std::boxed::Box;
use std::string::String;

/// Reference to a range of bytes encompassing a single valid JSON value in the
/// input data.
///
#[derive(Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct RawValue {
    json: str,
}

impl RawValue {
    fn from_borrowed(json: &str) -> &Self {
        unsafe { mem::transmute::<&str, &RawValue>(json) }
    }

    fn from_owned(json: Box<str>) -> Box<Self> {
        unsafe { mem::transmute::<Box<str>, Box<RawValue>>(json) }
    }

    fn into_owned(raw_value: Box<Self>) -> Box<str> {
        unsafe { mem::transmute::<Box<RawValue>, Box<str>>(raw_value) }
    }
}

impl Clone for Box<RawValue> {
    fn clone(&self) -> Self {
        (**self).to_owned()
    }
}

impl ToOwned for RawValue {
    type Owned = Box<RawValue>;

    fn to_owned(&self) -> Self::Owned {
        RawValue::from_owned(self.json.to_owned().into_boxed_str())
    }
}

impl Default for Box<RawValue> {
    fn default() -> Self {
        RawValue::from_borrowed("null").to_owned()
    }
}

impl Debug for RawValue {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        formatter
            .debug_tuple("RawValue")
            .field(&format_args!("{}", &self.json))
            .finish()
    }
}

impl Display for RawValue {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str(&self.json)
    }
}

impl RawValue {
    /// Convert an owned `String` of JSON data to an owned `RawValue`.
    ///
    /// This function is equivalent to `sonic_rs::from_str::<Box<RawValue>>`
    /// except that we avoid an allocation and memcpy if both of the following
    /// are true:
    ///
    /// - the input has no leading or trailing whitespace, and
    /// - the input has capacity equal to its length.
    pub fn from_string(json: String) -> Result<Box<Self>, Error> {
        {
            let borrowed = crate::from_str::<&Self>(&json)?;
            if borrowed.json.len() < json.len() {
                return Ok(borrowed.to_owned());
            }
        }
        Ok(Self::from_owned(json.into_boxed_str()))
    }

    pub fn from_json_str(json: &str) -> Result<&Self, Error> {
        crate::from_str::<&Self>(json)
    }

    /// Access the JSON text underlying a raw value.
    ///
    pub fn get(&self) -> &str {
        &self.json
    }
}

impl From<Box<RawValue>> for Box<str> {
    fn from(raw_value: Box<RawValue>) -> Self {
        RawValue::into_owned(raw_value)
    }
}

/// Convert a `T` into a boxed `RawValue`.
pub fn to_raw_value<T>(value: &T) -> Result<Box<RawValue>, Error>
where
    T: ?Sized + Serialize,
{
    let json_string = crate::to_string(value)?;
    Ok(RawValue::from_owned(json_string.into_boxed_str()))
}

pub(crate) const TOKEN: &str = "$sonic_rs::private::RawValue";

impl Serialize for RawValue {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        let mut s = serializer.serialize_struct(TOKEN, 1)?;
        s.serialize_field(TOKEN, &self.json)?;
        s.end()
    }
}

impl<'de: 'a, 'a> Deserialize<'de> for &'a RawValue {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        struct ReferenceVisitor;

        impl<'de> Visitor<'de> for ReferenceVisitor {
            type Value = &'de RawValue;

            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                write!(formatter, "any valid JSON value")
            }

            fn visit_map<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
            where
                V: MapAccess<'de>,
            {
                let value = visitor.next_key::<RawKey>()?;
                if value.is_none() {
                    return Err(de::Error::invalid_type(Unexpected::Map, &self));
                }
                visitor.next_value_seed(ReferenceFromString)
            }
        }

        deserializer.deserialize_newtype_struct(TOKEN, ReferenceVisitor)
    }
}

impl<'de> Deserialize<'de> for Box<RawValue> {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        struct BoxedVisitor;

        impl<'de> Visitor<'de> for BoxedVisitor {
            type Value = Box<RawValue>;

            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                write!(formatter, "any valid JSON value")
            }

            fn visit_map<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
            where
                V: MapAccess<'de>,
            {
                let value = visitor.next_key::<RawKey>()?;
                if value.is_none() {
                    return Err(de::Error::invalid_type(Unexpected::Map, &self));
                }
                visitor.next_value_seed(BoxedFromString)
            }
        }

        deserializer.deserialize_newtype_struct(TOKEN, BoxedVisitor)
    }
}

struct RawKey;

impl<'de> Deserialize<'de> for RawKey {
    fn deserialize<D>(deserializer: D) -> Result<RawKey, D::Error>
    where
        D: Deserializer<'de>,
    {
        struct FieldVisitor;

        impl<'de> Visitor<'de> for FieldVisitor {
            type Value = ();

            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                formatter.write_str("raw value")
            }

            fn visit_str<E>(self, s: &str) -> Result<(), E>
            where
                E: de::Error,
            {
                if s == TOKEN {
                    Ok(())
                } else {
                    Err(de::Error::custom("unexpected raw value"))
                }
            }
        }

        deserializer.deserialize_identifier(FieldVisitor)?;
        Ok(RawKey)
    }
}

pub struct ReferenceFromString;

impl<'de> DeserializeSeed<'de> for ReferenceFromString {
    type Value = &'de RawValue;

    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
    where
        D: Deserializer<'de>,
    {
        deserializer.deserialize_str(self)
    }
}

impl<'de> Visitor<'de> for ReferenceFromString {
    type Value = &'de RawValue;

    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        formatter.write_str("raw value")
    }

    fn visit_borrowed_str<E>(self, s: &'de str) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(RawValue::from_borrowed(s))
    }
}

pub struct BoxedFromString;

impl<'de> DeserializeSeed<'de> for BoxedFromString {
    type Value = Box<RawValue>;

    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
    where
        D: Deserializer<'de>,
    {
        deserializer.deserialize_str(self)
    }
}

impl<'de> Visitor<'de> for BoxedFromString {
    type Value = Box<RawValue>;

    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        formatter.write_str("raw value")
    }

    fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(RawValue::from_owned(s.to_owned().into_boxed_str()))
    }

    fn visit_string<E>(self, s: String) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(RawValue::from_owned(s.into_boxed_str()))
    }
}

struct RawKeyDeserializer;

impl<'de> Deserializer<'de> for RawKeyDeserializer {
    type Error = Error;

    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_borrowed_str(TOKEN)
    }

    forward_to_deserialize_any! {
        bool u8 u16 u32 u64 u128 i8 i16 i32 i64 i128 f32 f64 char str string seq
        bytes byte_buf map struct option unit newtype_struct ignored_any
        unit_struct tuple_struct tuple enum identifier
    }
}

pub struct OwnedRawDeserializer {
    pub raw_value: Option<String>,
}

impl<'de> MapAccess<'de> for OwnedRawDeserializer {
    type Error = Error;

    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
    where
        K: de::DeserializeSeed<'de>,
    {
        if self.raw_value.is_none() {
            return Ok(None);
        }
        seed.deserialize(RawKeyDeserializer).map(Some)
    }

    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
    where
        V: de::DeserializeSeed<'de>,
    {
        seed.deserialize(self.raw_value.take().unwrap().into_deserializer())
    }
}

pub struct BorrowedRawDeserializer<'de> {
    pub raw_value: Option<&'de str>,
}

impl<'de> MapAccess<'de> for BorrowedRawDeserializer<'de> {
    type Error = Error;

    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
    where
        K: de::DeserializeSeed<'de>,
    {
        if self.raw_value.is_none() {
            return Ok(None);
        }
        seed.deserialize(RawKeyDeserializer).map(Some)
    }

    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
    where
        V: de::DeserializeSeed<'de>,
    {
        seed.deserialize(BorrowedStrDeserializer::new(self.raw_value.take().unwrap()))
    }
}