use bytes::{Buf, BufMut};
use super::varint::VarInt;
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub struct UnexpectedEnd(pub usize);
pub type Result<T> = ::std::result::Result<T, UnexpectedEnd>;
pub trait Encode {
fn encode<B: BufMut>(&self, buf: &mut B);
}
pub trait Decode: Sized {
fn decode<B: Buf>(buf: &mut B) -> Result<Self>;
}
impl Encode for u8 {
fn encode<B: BufMut>(&self, buf: &mut B) {
buf.put_u8(*self);
}
}
impl Decode for u8 {
fn decode<B: Buf>(buf: &mut B) -> Result<u8> {
if buf.remaining() < 1 {
return Err(UnexpectedEnd(1));
}
Ok(buf.get_u8())
}
}
pub trait BufExt {
fn get<T: Decode>(&mut self) -> Result<T>;
fn get_var(&mut self) -> Result<u64>;
}
impl<T: Buf> BufExt for T {
fn get<U: Decode>(&mut self) -> Result<U> {
U::decode(self)
}
fn get_var(&mut self) -> Result<u64> {
Ok(VarInt::decode(self)?.into_inner())
}
}
pub trait BufMutExt {
fn write<T: Encode>(&mut self, x: T);
fn write_var(&mut self, x: u64);
}
impl<T: BufMut> BufMutExt for T {
fn write<U: Encode>(&mut self, x: U) {
x.encode(self);
}
fn write_var(&mut self, x: u64) {
VarInt::from_u64(x).unwrap().encode(self);
}
}