use std::{io, rc::Rc};
use crate::bytes::{Bytes, BytesMut, BytesVec};
pub trait EncoderDecoder:Encoder+Decoder{}
impl <T>EncoderDecoder for T where T:Encoder+Decoder{}
pub trait Encoder {
type EncodeItem;
type EncodeError: std::fmt::Debug;
fn encode(&self, item: Self::EncodeItem, dst: &mut BytesMut) -> Result<(), Self::EncodeError>;
fn encode_vec(&self, item: Self::EncodeItem, dst: &mut BytesVec) -> Result<(), Self::EncodeError> {
dst.with_bytes_mut(|dst| self.encode(item, dst))
}
}
pub trait Decoder {
type DecodeItem;
type DecodeError: std::fmt::Debug;
fn decode(&self, src: &mut BytesMut) -> Result<Option<Self::DecodeItem>, Self::DecodeError>;
fn decode_vec(&self, src: &mut BytesVec) -> Result<Option<Self::DecodeItem>, Self::DecodeError> {
src.with_bytes_mut(|src| self.decode(src))
}
}
impl<T> Encoder for Rc<T>
where
T: Encoder,
{
type EncodeItem = T::EncodeItem;
type EncodeError = T::EncodeError;
fn encode(&self, item: Self::EncodeItem, dst: &mut BytesMut) -> Result<(), Self::EncodeError> {
(**self).encode(item, dst)
}
}
impl<T> Decoder for Rc<T>
where
T: Decoder,
{
type DecodeItem = T::DecodeItem;
type DecodeError = T::DecodeError;
fn decode(&self, src: &mut BytesMut) -> Result<Option<Self::DecodeItem>, Self::DecodeError> {
(**self).decode(src)
}
}
#[derive(Debug, Copy, Clone)]
pub struct BytesCodec;
impl Encoder for BytesCodec {
type EncodeItem = Bytes;
type EncodeError = io::Error;
#[inline]
fn encode(&self, item: Bytes, dst: &mut BytesMut) -> Result<(), Self::EncodeError> {
dst.extend_from_slice(&item[..]);
Ok(())
}
}
impl Decoder for BytesCodec {
type DecodeItem = BytesMut;
type DecodeError = io::Error;
fn decode(&self, src: &mut BytesMut) -> Result<Option<Self::DecodeItem>, Self::DecodeError> {
if src.is_empty() {
Ok(None)
} else {
let len = src.len();
Ok(Some(src.split_to(len)))
}
}
}