Struct `FxHasher`

pub(in ::bridge) struct FxHasher { pub(in ::bridge::fxhash) hash: usize }

A speedy hash algorithm for use within rustc. The hashmap in alloc by default uses SipHash which isn't quite as speedy as we want. In the compiler we're not really worried about DOS attempts, so we use a fast non-cryptographic hash.

This is the same as the algorithm used by Firefox -- which is a homespun one not based on any widely-known algorithm -- though modified to produce 64-bit hash values instead of 32-bit hash values. It consistently out-performs an FNV-based hash within rustc itself -- the collision rate is similar or slightly worse than FNV, but the speed of the hash function itself is much higher because it works on up to 8 bytes at a time.

Fields

hash: usize

Implementations

`impl FxHasher`

fn add_to_hash(&mut self, i: usize)

Trait Implementations

`impl Default for FxHasher`

fn default() -> FxHasher

`impl Hasher for FxHasher`

fn write(&mut self, bytes: &[u8])
fn write_u8(&mut self, i: u8)
fn write_u16(&mut self, i: u16)
fn write_u32(&mut self, i: u32)
fn write_u64(&mut self, i: u64)
fn write_usize(&mut self, i: usize)
fn finish(&self) -> u64

Auto Trait Implementations

`impl Freeze for FxHasher`

`impl RefUnwindSafe for FxHasher`

`impl Send for FxHasher`

`impl Sync for FxHasher`

`impl Unpin for FxHasher`

`impl UnsafeUnpin for FxHasher`

`impl UnwindSafe for FxHasher`

Blanket Implementations

`impl<T> Any for FxHasher where T: 'static + ?Sized,`

fn type_id(&self) -> TypeId

`impl<T> Borrow<T> for FxHasher where T: ?Sized,`

fn borrow(&self) -> &T

`impl<T> BorrowMut<T> for FxHasher where T: ?Sized,`

fn borrow_mut(&mut self) -> &mut T

`impl<T> From<T> for FxHasher`

fn from(t: T) -> T: Returns the argument unchanged.

`impl<T> SizeHint for FxHasher where T: ?Sized,`

fn lower_bound(&self) -> usize
fn upper_bound(&self) -> Option<usize>

`impl<T> SizedTypeProperties for FxHasher`

`impl<T, U> Into<U> for FxHasher where U: From<T>,`

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

`impl<T, U> TryFrom<U> for FxHasher where U: Into<T>,`

type Error = never;
fn try_from(value: U) -> Result<T, never>

`impl<T, U> TryInto<U> for FxHasher where U: TryFrom<T>,`

type Error = <U as TryFrom<T>>::Error;
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>