mod key;
pub use self::key::BytesKey;
use std::hash::Hasher;
use std::{mem, slice};
pub trait Hash {
fn hash<H: Hasher>(&self, state: &mut H);
fn hash_slice<H: Hasher>(data: &[Self], state: &mut H)
where
Self: Sized,
{
for piece in data {
piece.hash(state);
}
}
}
macro_rules! impl_write {
($(($ty:ident, $meth:ident),)*) => {$(
impl Hash for $ty {
fn hash<H: Hasher>(&self, state: &mut H) {
state.$meth(*self)
}
fn hash_slice<H: Hasher>(data: &[$ty], state: &mut H) {
let newlen = data.len() * mem::size_of::<$ty>();
let ptr = data.as_ptr() as *const u8;
state.write(unsafe { slice::from_raw_parts(ptr, newlen) })
}
}
)*}
}
impl_write! {
(u8, write_u8),
(u16, write_u16),
(u32, write_u32),
(u64, write_u64),
(usize, write_usize),
(i8, write_i8),
(i16, write_i16),
(i32, write_i32),
(i64, write_i64),
(isize, write_isize),
(u128, write_u128),
(i128, write_i128),
}
impl Hash for bool {
fn hash<H: Hasher>(&self, state: &mut H) {
state.write_u8(*self as u8)
}
}
impl Hash for char {
fn hash<H: Hasher>(&self, state: &mut H) {
state.write_u32(*self as u32)
}
}
impl Hash for str {
fn hash<H: Hasher>(&self, state: &mut H) {
state.write(self.as_bytes());
}
}
impl Hash for String {
fn hash<H: Hasher>(&self, state: &mut H) {
state.write(self.as_bytes());
}
}
macro_rules! impl_hash_tuple {
() => (
impl Hash for () {
fn hash<H: Hasher>(&self, _state: &mut H) {}
}
);
( $($name:ident)+) => (
impl<$($name: Hash),*> Hash for ($($name,)*) where last_type!($($name,)+): ?Sized {
#[allow(non_snake_case)]
fn hash<S: Hasher>(&self, state: &mut S) {
let ($(ref $name,)*) = *self;
$($name.hash(state);)*
}
}
);
}
macro_rules! last_type {
($a:ident,) => { $a };
($a:ident, $($rest_a:ident,)+) => { last_type!($($rest_a,)+) };
}
impl_hash_tuple! {}
impl_hash_tuple! { A }
impl_hash_tuple! { A B }
impl_hash_tuple! { A B C }
impl_hash_tuple! { A B C D }
impl_hash_tuple! { A B C D E }
impl_hash_tuple! { A B C D E F }
impl_hash_tuple! { A B C D E F G }
impl_hash_tuple! { A B C D E F G H }
impl_hash_tuple! { A B C D E F G H I }
impl_hash_tuple! { A B C D E F G H I J }
impl_hash_tuple! { A B C D E F G H I J K }
impl_hash_tuple! { A B C D E F G H I J K L }
impl<T: Hash> Hash for [T] {
fn hash<H: Hasher>(&self, state: &mut H) {
Hash::hash_slice(self, state)
}
}
impl<T: Hash> Hash for Vec<T> {
fn hash<H: Hasher>(&self, state: &mut H) {
Hash::hash_slice(self, state)
}
}
impl<T: ?Sized + Hash> Hash for &T {
fn hash<H: Hasher>(&self, state: &mut H) {
(**self).hash(state);
}
}
impl<T: ?Sized + Hash> Hash for &mut T {
fn hash<H: Hasher>(&self, state: &mut H) {
(**self).hash(state);
}
}
impl<T: ?Sized> Hash for *const T {
fn hash<H: Hasher>(&self, state: &mut H) {
if mem::size_of::<Self>() == mem::size_of::<usize>() {
state.write_usize(*self as *const () as usize);
} else {
let (a, b) = unsafe { *(self as *const Self as *const (usize, usize)) };
state.write_usize(a);
state.write_usize(b);
}
}
}
impl<T: ?Sized> Hash for *mut T {
fn hash<H: Hasher>(&self, state: &mut H) {
if mem::size_of::<Self>() == mem::size_of::<usize>() {
state.write_usize(*self as *const () as usize);
} else {
let (a, b) = unsafe { *(self as *const Self as *const (usize, usize)) };
state.write_usize(a);
state.write_usize(b);
}
}
}