Crate fasthash

A suite of non-cryptographic hash functions for Rust.

Example

use std::hash::{Hash, Hasher};

use fasthash::{metro, MetroHasher};

fn hash<T: Hash>(t: &T) -> u64 {
    let mut s: MetroHasher = Default::default();
    t.hash(&mut s);
    s.finish()
}

let h = metro::hash64(b"hello world\xff");

assert_eq!(h, hash(&"hello world"));

By default, HashMap uses a hashing algorithm selected to provide resistance against HashDoS attacks. The hashing algorithm can be replaced on a per-HashMap basis using the HashMap::with_hasher or HashMap::with_capacity_and_hasher methods.

It also cowork with HashMap or HashSet, act as a hash function

use std::collections::HashSet;

use fasthash::spooky::SpookyHash128;

let mut set = HashSet::with_hasher(SpookyHash128 {});
set.insert(2);

Or use RandomState with a random seed.

use std::hash::{Hash, Hasher};
use std::collections::HashMap;

use fasthash::RandomState;
use fasthash::city::CityHash64;

let s = RandomState::<CityHash64>::new();
let mut map = HashMap::with_hasher(s);

assert_eq!(map.insert(37, "a"), None);
assert_eq!(map.is_empty(), false);

map.insert(37, "b");
assert_eq!(map.insert(37, "c"), Some("b"));
assert_eq!(map[&37], "c");

Reexports

pub use city::{CityHasher64 as CityHasher, CityHasherCrc128 as CityHasherExt};

pub use farm::{FarmHasher64 as FarmHasher, FarmHasher128 as FarmHasherExt};

pub use lookup3::Lookup3Hasher;

pub use metro::{MetroHasher64Crc_1 as MetroHasher, MetroHasher128Crc_1 as MetroHasherExt};

pub use mum::MumHasher;

pub use murmur::MurmurHasher;

pub use murmur2::Murmur2Hasher_x64_64 as Murmur2Hasher;

pub use murmur3::{Murmur3Hasher_x64_128 as Murmur3Hasher, Murmur3Hasher_x64_128 as Murmur3HasherExt};

pub use sea::SeaHasher64 as SeaHasher;

pub use spooky::{SpookyHasher128 as SpookyHasher, SpookyHasher128 as SpookyHasherExt};

pub use t1ha::T1ha64CrcHasher as T1haHasher;

pub use xx::XXHasher64 as XXHasher;

Modules

city	CityHash, a family of hash functions for strings.
farm	FarmHash, a family of hash functions.
lookup3	Lookup3, non-cryptographic hash.
metro	MetroHash, Exceptionally fast and statistically robust hash functions
mum	MumHash, Hashing functions and PRNGs based on them
murmur	Murmur, a suite of non-cryptographic hash functions that was used for hash-based lookups.
murmur2	Murmur2, a suite of non-cryptographic hash functions that was used for hash-based lookups.
murmur3	Murmur3, a suite of non-cryptographic hash functions that was used for hash-based lookups.
sea	SeaHash: A bizarrely fast hash function.
spooky	SpookyHash: a 128-bit noncryptographic hash function
t1ha	Fast Positive Hash, aka "Позитивный Хэш"
xx	xxHash - Extremely fast hash algorithm

Structs

RandomState	RandomState provides the default state for HashMap or HashSet types.
Seed	Generate hash seeds

Traits

BufHasher	Hasher in the buffer mode for short key
FastHash	Fast non-cryptographic hash functions
FastHasher	Fast non-cryptographic hasher
Fingerprint	Generate a good, portable, forever-fixed hash value
HasherExt	A trait which represents the ability to hash an arbitrary stream of bytes.
StreamHasher	Hasher in the streaming mode without buffer