serdebin 0.1.0

serializer/deserializer to minimal binary format
Documentation
use crate::consts::{U16_MAX, U16_TAG, U32_MAX, U32_TAG, U64_TAG, U8_MAX, U8_TAG};
use serde::ser::{
    SerializeMap, SerializeSeq, SerializeStruct, SerializeStructVariant, SerializeTuple,
    SerializeTupleStruct, SerializeTupleVariant,
};
use serde::{ser, Serialize};

use crate::error::SerializerError;

#[derive(Default)]
pub struct BinSerializer {
    pub(crate) bts: Vec<u8>,
}

impl BinSerializer {
    fn put_size(&mut self, size: usize) {
        if size < U8_MAX {
            self.bts.push(U8_TAG);
            self.bts.push((size as u8).to_le());
            return;
        }
        if size < U16_MAX {
            self.bts.push(U16_TAG);
            self.bts.extend((size as u16).to_le_bytes());
            return;
        }
        if size < U32_MAX {
            self.bts.push(U32_TAG);
            self.bts.extend((size as u32).to_le_bytes());
            return;
        }
        self.bts.push(U64_TAG);
        self.bts.extend((size as u64).to_le_bytes());
    }
}

impl<'a> ser::Serializer for &'a mut BinSerializer {
    type Ok = ();
    type Error = SerializerError;
    type SerializeSeq = Self;
    type SerializeTuple = Self;
    type SerializeTupleStruct = Self;
    type SerializeTupleVariant = Self;
    type SerializeMap = Self;
    type SerializeStruct = Self;
    type SerializeStructVariant = Self;

    fn serialize_bool(self, v: bool) -> Result<Self::Ok, Self::Error> {
        self.bts.push(v as u8);
        Ok(())
    }

    fn serialize_i8(self, v: i8) -> Result<Self::Ok, Self::Error> {
        self.bts.extend(v.to_le_bytes());
        Ok(())
    }

    fn serialize_i16(self, v: i16) -> Result<Self::Ok, Self::Error> {
        self.bts.extend(v.to_le_bytes());
        Ok(())
    }

    fn serialize_i32(self, v: i32) -> Result<Self::Ok, Self::Error> {
        self.bts.extend(v.to_le_bytes());
        Ok(())
    }

    fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error> {
        self.bts.extend(v.to_le_bytes());
        Ok(())
    }

    fn serialize_u8(self, v: u8) -> Result<Self::Ok, Self::Error> {
        self.bts.push(v.to_le());
        Ok(())
    }

    fn serialize_u16(self, v: u16) -> Result<Self::Ok, Self::Error> {
        self.bts.extend(v.to_le_bytes());
        Ok(())
    }

    fn serialize_u32(self, v: u32) -> Result<Self::Ok, Self::Error> {
        self.bts.extend(v.to_le_bytes());
        Ok(())
    }

    fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error> {
        self.bts.extend(v.to_le_bytes());
        Ok(())
    }

    fn serialize_f32(self, v: f32) -> Result<Self::Ok, Self::Error> {
        self.bts.extend(v.to_le_bytes());
        Ok(())
    }

    fn serialize_f64(self, v: f64) -> Result<Self::Ok, Self::Error> {
        self.bts.extend(v.to_le_bytes());
        Ok(())
    }

    fn serialize_char(self, v: char) -> Result<Self::Ok, Self::Error> {
        self.serialize_str(&String::from(v))
    }

    fn serialize_str(self, v: &str) -> Result<Self::Ok, Self::Error> {
        self.put_size(v.len());
        self.bts.extend(v.bytes());
        Ok(())
    }

    fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok, Self::Error> {
        self.put_size(v.len());
        self.bts.extend(v);
        Ok(())
    }

    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
        self.bts.push(0);
        Ok(())
    }

    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
    where
        T: Serialize,
    {
        self.bts.push(1);
        value.serialize(self)
    }

    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
        Ok(())
    }

    fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
        Ok(())
    }

    fn serialize_unit_variant(
        self,
        _: &'static str,
        variant_index: u32,
        _: &'static str,
    ) -> Result<Self::Ok, Self::Error> {
        self.put_size(variant_index as usize);
        Ok(())
    }

    fn serialize_newtype_struct<T: ?Sized>(
        self,
        _: &'static str,
        value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
        T: Serialize,
    {
        value.serialize(self)
    }

    fn serialize_newtype_variant<T: ?Sized>(
        self,
        _: &'static str,
        variant_index: u32,
        _: &'static str,
        value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
        T: Serialize,
    {
        self.put_size(variant_index as usize);
        value.serialize(self)
    }

    fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
        self.put_size(len.unwrap_or(0));
        Ok(self)
    }

    fn serialize_tuple(self, _: usize) -> Result<Self::SerializeTuple, Self::Error> {
        Ok(self)
    }

    fn serialize_tuple_struct(
        self,
        _: &'static str,
        len: usize,
    ) -> Result<Self::SerializeTupleStruct, Self::Error> {
        self.serialize_tuple(len)
    }

    fn serialize_tuple_variant(
        self,
        _: &'static str,
        variant_index: u32,
        _: &'static str,
        len: usize,
    ) -> Result<Self::SerializeTupleVariant, Self::Error> {
        self.put_size(variant_index as usize);
        self.put_size(len);
        Ok(self)
    }

    fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
        self.put_size(len.unwrap_or(0));
        Ok(self)
    }

    fn serialize_struct(
        self,
        _: &'static str,
        _: usize,
    ) -> Result<Self::SerializeStruct, Self::Error> {
        Ok(self)
    }

    fn serialize_struct_variant(
        self,
        _: &'static str,
        variant_index: u32,
        _: &'static str,
        _: usize,
    ) -> Result<Self::SerializeStructVariant, Self::Error> {
        self.put_size(variant_index as usize);
        Ok(self)
    }
}

impl<'a> SerializeSeq for &'a mut BinSerializer {
    type Ok = ();
    type Error = SerializerError;

    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        Ok(())
    }
}

impl<'a> SerializeTuple for &'a mut BinSerializer {
    type Ok = ();
    type Error = SerializerError;

    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        Ok(())
    }
}

impl<'a> SerializeTupleStruct for &'a mut BinSerializer {
    type Ok = ();
    type Error = SerializerError;

    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        Ok(())
    }
}

impl<'a> SerializeTupleVariant for &'a mut BinSerializer {
    type Ok = ();
    type Error = SerializerError;

    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        Ok(())
    }
}

impl<'a> SerializeMap for &'a mut BinSerializer {
    type Ok = ();
    type Error = SerializerError;

    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        key.serialize(&mut **self)
    }

    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        Ok(())
    }
}

impl<'a> SerializeStruct for &'a mut BinSerializer {
    type Ok = ();
    type Error = SerializerError;

    fn serialize_field<T: ?Sized>(&mut self, _: &'static str, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        Ok(())
    }
}

impl<'a> SerializeStructVariant for &'a mut BinSerializer {
    type Ok = ();
    type Error = SerializerError;

    fn serialize_field<T: ?Sized>(&mut self, _: &'static str, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        Ok(())
    }
}