Struct rustc_hash::FxHasher

source ·
pub struct FxHasher { /* private fields */ }
Expand description

A speedy hash algorithm for use within rustc. The hashmap in liballoc 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.

Trait Implementations§

source§

impl Default for FxHasher

source§

fn default() -> FxHasher

Returns the “default value” for a type. Read more
source§

impl Hasher for FxHasher

source§

fn write(&mut self, bytes: &[u8])

Writes some data into this Hasher. Read more
source§

fn write_u8(&mut self, i: u8)

Writes a single u8 into this hasher.
source§

fn write_u16(&mut self, i: u16)

Writes a single u16 into this hasher.
source§

fn write_u32(&mut self, i: u32)

Writes a single u32 into this hasher.
source§

fn write_u64(&mut self, i: u64)

Writes a single u64 into this hasher.
source§

fn write_usize(&mut self, i: usize)

Writes a single usize into this hasher.
source§

fn finish(&self) -> u64

Returns the hash value for the values written so far. Read more
1.26.0 · source§

fn write_u128(&mut self, i: u128)

Writes a single u128 into this hasher.
1.3.0 · source§

fn write_i8(&mut self, i: i8)

Writes a single i8 into this hasher.
1.3.0 · source§

fn write_i16(&mut self, i: i16)

Writes a single i16 into this hasher.
1.3.0 · source§

fn write_i32(&mut self, i: i32)

Writes a single i32 into this hasher.
1.3.0 · source§

fn write_i64(&mut self, i: i64)

Writes a single i64 into this hasher.
1.26.0 · source§

fn write_i128(&mut self, i: i128)

Writes a single i128 into this hasher.
1.3.0 · source§

fn write_isize(&mut self, i: isize)

Writes a single isize into this hasher.
source§

fn write_length_prefix(&mut self, len: usize)

🔬This is a nightly-only experimental API. (hasher_prefixfree_extras)
Writes a length prefix into this hasher, as part of being prefix-free. Read more
source§

fn write_str(&mut self, s: &str)

🔬This is a nightly-only experimental API. (hasher_prefixfree_extras)
Writes a single str into this hasher. Read more

Auto Trait Implementations§

Blanket Implementations§

source§

impl<T> Any for Twhere T: 'static + ?Sized,

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

impl<T> Borrow<T> for Twhere T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for Twhere T: ?Sized,

source§

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

Mutably borrows from an owned value. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T, U> Into<U> for Twhere U: From<T>,

source§

fn into(self) -> U

Calls U::from(self).

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

source§

impl<T, U> TryFrom<U> for Twhere U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
source§

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

Performs the conversion.