Struct rustc_ap_rustc_data_structures::fx::FxHasher

pub struct FxHasher { /* fields omitted */ }

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

impl Default for FxHasher

pub fn default() -> FxHasher

Returns the “default value” for a type.

impl Hasher for FxHasher

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

Writes some data into this Hasher.

pub fn write_u8(&mut self, i: u8)

Writes a single u8 into this hasher.

pub fn write_u16(&mut self, i: u16)

Writes a single u16 into this hasher.

pub fn write_u32(&mut self, i: u32)

Writes a single u32 into this hasher.

pub fn write_u64(&mut self, i: u64)

Writes a single u64 into this hasher.

pub fn write_usize(&mut self, i: usize)

Writes a single usize into this hasher.

pub fn finish(&self) -> u64

Returns the hash value for the values written so far.

fn write_u128(&mut self, i: u128)

Writes a single u128 into this hasher.

fn write_i8(&mut self, i: i8)

Writes a single i8 into this hasher.

fn write_i16(&mut self, i: i16)

Writes a single i16 into this hasher.

fn write_i32(&mut self, i: i32)

Writes a single i32 into this hasher.

fn write_i64(&mut self, i: i64)

Writes a single i64 into this hasher.

fn write_i128(&mut self, i: i128)

Writes a single i128 into this hasher.

fn write_isize(&mut self, i: isize)

Writes a single isize into this hasher.