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::Hash128;

let mut set = HashSet::with_hasher(Hash128);
set.insert(2);

Or use RandomState<CityHash64> with a random seed.

use std::collections::HashMap;

use fasthash::{city, RandomState};

let s = RandomState::<city::Hash64>::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");

Re-exports

• pub use farm::Hasher128 as FarmHasherExt;
• pub use farm::Hasher64 as FarmHasher;
• pub use lookup3::Hasher32 as Lookup3Hasher;
• pub use mum::Hasher64 as MumHasher;
• pub use murmur::Hasher32 as MurmurHasher;
• pub use murmur3::Hasher32 as Murmur3Hasher;
• pub use sea::Hasher64 as SeaHasher;
• pub use spooky::Hasher128 as SpookyHasherExt;
• pub use spooky::Hasher64 as SpookyHasher;
• pub use t1ha::t1ha0;
• pub use t1ha::t1ha1;
• pub use t1ha::t1ha2;
• pub use t1ha2::Hasher128 as T1haHasherExt;
• pub use t1ha2::Hasher64 as T1haHasher;
• pub use xx::Hasher64 as XXHasher;
• pub use murmur2::Hasher64_x64 as Murmur2Hasher;
• pub use murmur3::Hasher128_x64 as Murmur3HasherExt;
• pub use city::Hasher64 as CityHasher;
• pub use city::crc::Hasher128 as CityHasherExt;
• pub use metro::crc::Hasher128_1 as MetroHasherExt;
• pub use metro::crc::Hasher64_1 as MetroHasher;

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