Trait FastHash 

pub trait FastHash {
    type Output: Copy + Eq + Debug + Default;
    type Seed: Copy + Debug + Default;

    const OUTPUT_SIZE: usize;

    // Required method
    fn hash_with_seed(seed: Self::Seed, data: &[u8]) -> Self::Output;

    // Provided method
    fn hash(data: &[u8]) -> Self::Output { ... }
}

A fast non-cryptographic hash.

These hashes are suitable for hash tables, sharding, fingerprints, and other non-adversarial settings. They are not suitable for signatures, MACs, password hashing, or untrusted inputs where collision attacks matter.

This trait is intentionally one-shot. Streaming APIs for fast hashes often require algorithm-specific buffering and are exposed as concrete types.

Examples

let hash = MyHash::hash(b"hello world");
let seeded = MyHash::hash_with_seed(42, b"hello world");
assert_ne!(hash, seeded);

Required Associated Constants

const OUTPUT_SIZE: usize

Output size in bytes.

Required Associated Types

type Output: Copy + Eq + Debug + Default

Hash output type.

type Seed: Copy + Debug + Default

Seed type (typically u64).

Required Methods

fn hash_with_seed(seed: Self::Seed, data: &[u8]) -> Self::Output

Compute the hash of data using seed.

Provided Methods

fn hash(data: &[u8]) -> Self::Output

Compute the hash of data using a default seed.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl FastHash for RapidHash64

Available on (crate features sha2 or sha3 or blake2b or blake2s or blake3 or ascon-hash or xxh3 or rapidhash) and (crate features xxh3 or rapidhash) and crate feature rapidhash only.

const OUTPUT_SIZE: usize = 8

type Output = u64

type Seed = u64

impl FastHash for RapidHash128

Available on (crate features sha2 or sha3 or blake2b or blake2s or blake3 or ascon-hash or xxh3 or rapidhash) and (crate features xxh3 or rapidhash) and crate feature rapidhash only.

const OUTPUT_SIZE: usize = 16

type Output = u128

type Seed = u64

impl FastHash for RapidHashFast64

Available on (crate features sha2 or sha3 or blake2b or blake2s or blake3 or ascon-hash or xxh3 or rapidhash) and (crate features xxh3 or rapidhash) and crate feature rapidhash only.

const OUTPUT_SIZE: usize = 8

type Output = u64

type Seed = u64

impl FastHash for RapidHashFast128

Available on (crate features sha2 or sha3 or blake2b or blake2s or blake3 or ascon-hash or xxh3 or rapidhash) and (crate features xxh3 or rapidhash) and crate feature rapidhash only.

const OUTPUT_SIZE: usize = 16

type Output = u128

type Seed = u64

impl FastHash for Xxh3_64

Available on (crate features sha2 or sha3 or blake2b or blake2s or blake3 or ascon-hash or xxh3 or rapidhash) and (crate features xxh3 or rapidhash) and crate feature xxh3 only.

const OUTPUT_SIZE: usize = 8

type Output = u64

type Seed = u64

impl FastHash for Xxh3_128

Available on (crate features sha2 or sha3 or blake2b or blake2s or blake3 or ascon-hash or xxh3 or rapidhash) and (crate features xxh3 or rapidhash) and crate feature xxh3 only.

const OUTPUT_SIZE: usize = 16

type Output = u128

type Seed = u64