use std::alloc::Allocator;
use std::borrow::Cow;
use std::cell::{Cell, RefCell};
use std::marker::PhantomData;
use std::path;
use std::rc::Rc;
use std::sync::Arc;
const STR_SENTINEL: u8 = 0xC1;
pub trait Encoder {
fn emit_usize(&mut self, v: usize);
fn emit_u128(&mut self, v: u128);
fn emit_u64(&mut self, v: u64);
fn emit_u32(&mut self, v: u32);
fn emit_u16(&mut self, v: u16);
fn emit_u8(&mut self, v: u8);
fn emit_isize(&mut self, v: isize);
fn emit_i128(&mut self, v: i128);
fn emit_i64(&mut self, v: i64);
fn emit_i32(&mut self, v: i32);
fn emit_i16(&mut self, v: i16);
#[inline]
fn emit_i8(&mut self, v: i8) {
self.emit_u8(v as u8);
}
#[inline]
fn emit_bool(&mut self, v: bool) {
self.emit_u8(if v { 1 } else { 0 });
}
#[inline]
fn emit_char(&mut self, v: char) {
self.emit_u32(v as u32);
}
#[inline]
fn emit_str(&mut self, v: &str) {
self.emit_usize(v.len());
self.emit_raw_bytes(v.as_bytes());
self.emit_u8(STR_SENTINEL);
}
fn emit_raw_bytes(&mut self, s: &[u8]);
fn emit_enum_variant<F>(&mut self, v_id: usize, f: F)
where
F: FnOnce(&mut Self),
{
self.emit_usize(v_id);
f(self);
}
}
pub trait Decoder {
fn read_usize(&mut self) -> usize;
fn read_u128(&mut self) -> u128;
fn read_u64(&mut self) -> u64;
fn read_u32(&mut self) -> u32;
fn read_u16(&mut self) -> u16;
fn read_u8(&mut self) -> u8;
fn read_isize(&mut self) -> isize;
fn read_i128(&mut self) -> i128;
fn read_i64(&mut self) -> i64;
fn read_i32(&mut self) -> i32;
fn read_i16(&mut self) -> i16;
#[inline]
fn read_i8(&mut self) -> i8 {
self.read_u8() as i8
}
#[inline]
fn read_bool(&mut self) -> bool {
let value = self.read_u8();
value != 0
}
#[inline]
fn read_char(&mut self) -> char {
let bits = self.read_u32();
std::char::from_u32(bits).unwrap()
}
#[inline]
fn read_str(&mut self) -> &str {
let len = self.read_usize();
let bytes = self.read_raw_bytes(len + 1);
assert!(bytes[len] == STR_SENTINEL);
unsafe { std::str::from_utf8_unchecked(&bytes[..len]) }
}
fn read_raw_bytes(&mut self, len: usize) -> &[u8];
fn peek_byte(&self) -> u8;
fn position(&self) -> usize;
}
pub trait Encodable<S: Encoder> {
fn encode(&self, s: &mut S);
}
pub trait Decodable<D: Decoder>: Sized {
fn decode(d: &mut D) -> Self;
}
macro_rules! direct_serialize_impls {
($($ty:ident $emit_method:ident $read_method:ident),*) => {
$(
impl<S: Encoder> Encodable<S> for $ty {
fn encode(&self, s: &mut S) {
s.$emit_method(*self);
}
}
impl<D: Decoder> Decodable<D> for $ty {
fn decode(d: &mut D) -> $ty {
d.$read_method()
}
}
)*
}
}
direct_serialize_impls! {
usize emit_usize read_usize,
u8 emit_u8 read_u8,
u16 emit_u16 read_u16,
u32 emit_u32 read_u32,
u64 emit_u64 read_u64,
u128 emit_u128 read_u128,
isize emit_isize read_isize,
i8 emit_i8 read_i8,
i16 emit_i16 read_i16,
i32 emit_i32 read_i32,
i64 emit_i64 read_i64,
i128 emit_i128 read_i128,
bool emit_bool read_bool,
char emit_char read_char
}
impl<S: Encoder, T: ?Sized> Encodable<S> for &T
where
T: Encodable<S>,
{
fn encode(&self, s: &mut S) {
(**self).encode(s)
}
}
impl<S: Encoder> Encodable<S> for ! {
fn encode(&self, _s: &mut S) {
unreachable!();
}
}
impl<D: Decoder> Decodable<D> for ! {
fn decode(_d: &mut D) -> ! {
unreachable!()
}
}
impl<S: Encoder> Encodable<S> for ::std::num::NonZeroU32 {
fn encode(&self, s: &mut S) {
s.emit_u32(self.get());
}
}
impl<D: Decoder> Decodable<D> for ::std::num::NonZeroU32 {
fn decode(d: &mut D) -> Self {
::std::num::NonZeroU32::new(d.read_u32()).unwrap()
}
}
impl<S: Encoder> Encodable<S> for str {
fn encode(&self, s: &mut S) {
s.emit_str(self);
}
}
impl<S: Encoder> Encodable<S> for String {
fn encode(&self, s: &mut S) {
s.emit_str(&self[..]);
}
}
impl<D: Decoder> Decodable<D> for String {
fn decode(d: &mut D) -> String {
d.read_str().to_owned()
}
}
impl<S: Encoder> Encodable<S> for () {
fn encode(&self, _s: &mut S) {}
}
impl<D: Decoder> Decodable<D> for () {
fn decode(_: &mut D) -> () {}
}
impl<S: Encoder, T> Encodable<S> for PhantomData<T> {
fn encode(&self, _s: &mut S) {}
}
impl<D: Decoder, T> Decodable<D> for PhantomData<T> {
fn decode(_: &mut D) -> PhantomData<T> {
PhantomData
}
}
impl<D: Decoder, A: Allocator + Default, T: Decodable<D>> Decodable<D> for Box<[T], A> {
fn decode(d: &mut D) -> Box<[T], A> {
let v: Vec<T, A> = Decodable::decode(d);
v.into_boxed_slice()
}
}
impl<S: Encoder, T: Encodable<S>> Encodable<S> for Rc<T> {
fn encode(&self, s: &mut S) {
(**self).encode(s);
}
}
impl<D: Decoder, T: Decodable<D>> Decodable<D> for Rc<T> {
fn decode(d: &mut D) -> Rc<T> {
Rc::new(Decodable::decode(d))
}
}
impl<S: Encoder, T: Encodable<S>> Encodable<S> for [T] {
default fn encode(&self, s: &mut S) {
s.emit_usize(self.len());
for e in self.iter() {
e.encode(s);
}
}
}
impl<S: Encoder, T: Encodable<S>> Encodable<S> for Vec<T> {
fn encode(&self, s: &mut S) {
let slice: &[T] = self;
slice.encode(s);
}
}
impl<D: Decoder, T: Decodable<D>, A: Allocator + Default> Decodable<D> for Vec<T, A> {
default fn decode(d: &mut D) -> Vec<T, A> {
let len = d.read_usize();
let allocator = A::default();
let mut vec = Vec::with_capacity_in(len, allocator);
unsafe {
let ptr: *mut T = vec.as_mut_ptr();
for i in 0..len {
std::ptr::write(ptr.add(i), Decodable::decode(d));
}
vec.set_len(len);
}
vec
}
}
impl<S: Encoder, T: Encodable<S>, const N: usize> Encodable<S> for [T; N] {
fn encode(&self, s: &mut S) {
let slice: &[T] = self;
slice.encode(s);
}
}
impl<D: Decoder, const N: usize> Decodable<D> for [u8; N] {
fn decode(d: &mut D) -> [u8; N] {
let len = d.read_usize();
assert!(len == N);
let mut v = [0u8; N];
for i in 0..len {
v[i] = Decodable::decode(d);
}
v
}
}
impl<'a, S: Encoder, T: Encodable<S>> Encodable<S> for Cow<'a, [T]>
where
[T]: ToOwned<Owned = Vec<T>>,
{
fn encode(&self, s: &mut S) {
let slice: &[T] = self;
slice.encode(s);
}
}
impl<D: Decoder, T: Decodable<D> + ToOwned> Decodable<D> for Cow<'static, [T]>
where
[T]: ToOwned<Owned = Vec<T>>,
{
fn decode(d: &mut D) -> Cow<'static, [T]> {
let v: Vec<T> = Decodable::decode(d);
Cow::Owned(v)
}
}
impl<'a, S: Encoder> Encodable<S> for Cow<'a, str> {
fn encode(&self, s: &mut S) {
let val: &str = self;
val.encode(s)
}
}
impl<'a, D: Decoder> Decodable<D> for Cow<'a, str> {
fn decode(d: &mut D) -> Cow<'static, str> {
let v: String = Decodable::decode(d);
Cow::Owned(v)
}
}
impl<S: Encoder, T: Encodable<S>> Encodable<S> for Option<T> {
fn encode(&self, s: &mut S) {
match *self {
None => s.emit_enum_variant(0, |_| {}),
Some(ref v) => s.emit_enum_variant(1, |s| v.encode(s)),
}
}
}
impl<D: Decoder, T: Decodable<D>> Decodable<D> for Option<T> {
fn decode(d: &mut D) -> Option<T> {
match d.read_usize() {
0 => None,
1 => Some(Decodable::decode(d)),
_ => panic!("Encountered invalid discriminant while decoding `Option`."),
}
}
}
impl<S: Encoder, T1: Encodable<S>, T2: Encodable<S>> Encodable<S> for Result<T1, T2> {
fn encode(&self, s: &mut S) {
match *self {
Ok(ref v) => s.emit_enum_variant(0, |s| v.encode(s)),
Err(ref v) => s.emit_enum_variant(1, |s| v.encode(s)),
}
}
}
impl<D: Decoder, T1: Decodable<D>, T2: Decodable<D>> Decodable<D> for Result<T1, T2> {
fn decode(d: &mut D) -> Result<T1, T2> {
match d.read_usize() {
0 => Ok(T1::decode(d)),
1 => Err(T2::decode(d)),
_ => panic!("Encountered invalid discriminant while decoding `Result`."),
}
}
}
macro_rules! peel {
($name:ident, $($other:ident,)*) => (tuple! { $($other,)* })
}
macro_rules! tuple {
() => ();
( $($name:ident,)+ ) => (
impl<D: Decoder, $($name: Decodable<D>),+> Decodable<D> for ($($name,)+) {
fn decode(d: &mut D) -> ($($name,)+) {
($({ let element: $name = Decodable::decode(d); element },)+)
}
}
impl<S: Encoder, $($name: Encodable<S>),+> Encodable<S> for ($($name,)+) {
#[allow(non_snake_case)]
fn encode(&self, s: &mut S) {
let ($(ref $name,)+) = *self;
$($name.encode(s);)+
}
}
peel! { $($name,)+ }
)
}
tuple! { T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, }
impl<S: Encoder> Encodable<S> for path::Path {
fn encode(&self, e: &mut S) {
self.to_str().unwrap().encode(e);
}
}
impl<S: Encoder> Encodable<S> for path::PathBuf {
fn encode(&self, e: &mut S) {
path::Path::encode(self, e);
}
}
impl<D: Decoder> Decodable<D> for path::PathBuf {
fn decode(d: &mut D) -> path::PathBuf {
let bytes: String = Decodable::decode(d);
path::PathBuf::from(bytes)
}
}
impl<S: Encoder, T: Encodable<S> + Copy> Encodable<S> for Cell<T> {
fn encode(&self, s: &mut S) {
self.get().encode(s);
}
}
impl<D: Decoder, T: Decodable<D> + Copy> Decodable<D> for Cell<T> {
fn decode(d: &mut D) -> Cell<T> {
Cell::new(Decodable::decode(d))
}
}
impl<S: Encoder, T: Encodable<S>> Encodable<S> for RefCell<T> {
fn encode(&self, s: &mut S) {
self.borrow().encode(s);
}
}
impl<D: Decoder, T: Decodable<D>> Decodable<D> for RefCell<T> {
fn decode(d: &mut D) -> RefCell<T> {
RefCell::new(Decodable::decode(d))
}
}
impl<S: Encoder, T: Encodable<S>> Encodable<S> for Arc<T> {
fn encode(&self, s: &mut S) {
(**self).encode(s);
}
}
impl<D: Decoder, T: Decodable<D>> Decodable<D> for Arc<T> {
fn decode(d: &mut D) -> Arc<T> {
Arc::new(Decodable::decode(d))
}
}
impl<S: Encoder, T: ?Sized + Encodable<S>, A: Allocator + Default> Encodable<S> for Box<T, A> {
fn encode(&self, s: &mut S) {
(**self).encode(s)
}
}
impl<D: Decoder, A: Allocator + Default, T: Decodable<D>> Decodable<D> for Box<T, A> {
fn decode(d: &mut D) -> Box<T, A> {
let allocator = A::default();
Box::new_in(Decodable::decode(d), allocator)
}
}