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 Hasher for FxHasher
impl Hasher for FxHasher
source§fn write_usize(&mut self, i: usize)
fn write_usize(&mut self, i: usize)
Writes a single
usize
into this hasher.1.26.0 · source§fn write_u128(&mut self, i: u128)
fn write_u128(&mut self, i: u128)
Writes a single
u128
into this hasher.1.26.0 · source§fn write_i128(&mut self, i: i128)
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)
fn write_isize(&mut self, i: isize)
Writes a single
isize
into this hasher.source§fn write_length_prefix(&mut self, len: usize)
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
Auto Trait Implementations§
impl RefUnwindSafe for FxHasher
impl Send for FxHasher
impl Sync for FxHasher
impl Unpin for FxHasher
impl UnwindSafe for FxHasher
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more