Trait Fnv

pub trait Fnv
where
    Self: 'static + Copy + WrappingMul + BitXor<Output = Self>,
    u8: AsPrimitive<Self>,
{
    const PRIME: Self;
    const OFFSET_BASIS: Self;

    // Provided methods
    fn fnv1<I>(self, data: I) -> Self
       where I: IntoIterator<Item = u8> { ... }
    fn fnv1a<I>(self, data: I) -> Self
       where I: IntoIterator<Item = u8> { ... }
}

Fowler-Noll-Vo Hashes

Both FNV-1 and FNV-1a are provided.

Note that:

• FNV is not a cryptographic hash.
• FNV is not resistant to “hash flooding” denial-of-service attacks.

Required Associated Constants

const PRIME: Self

The FNV prime

const OFFSET_BASIS: Self

The FNV offset basis

Provided Methods

fn fnv1<I>(self, data: I) -> Self

where I: IntoIterator<Item = u8>,

Compute the Fowler-Noll-Vo hash FNV-1 (multiply before xor)

fn fnv1a<I>(self, data: I) -> Self

where I: IntoIterator<Item = u8>,

Compute the Fowler-Noll-Vo hash FNV-1a (xor before multiply)

use yafnv::Fnv;

// Test vectors from
// https://datatracker.ietf.org/doc/draft-eastlake-fnv/21/
for (data, h32, h64) in [
    ("", 0x811c9dc5, 0xcbf29ce484222325),
    ("a", 0xe40c292c, 0xaf63dc4c8601ec8c),
    ("foobar", 0xbf9cf968, 0x85944171f73967e8),
] {
    let data = data.as_bytes().iter().copied();
    assert_eq!(u32::OFFSET_BASIS.fnv1a(data.clone()), h32);
    assert_eq!(u64::OFFSET_BASIS.fnv1a(data), h64);
}

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.

Implementations on Foreign Types

impl Fnv for u32

const PRIME: u32 = 16_777_619u32

const OFFSET_BASIS: u32 = 2_166_136_261u32

impl Fnv for u64

const PRIME: u64 = 1_099_511_628_211u64

const OFFSET_BASIS: u64 = 14_695_981_039_346_656_037u64

impl Fnv for u128

const PRIME: u128 = 309_485_009_821_345_068_724_781_371u128

const OFFSET_BASIS: u128 = 144_066_263_297_769_815_596_495_629_667_062_367_629u128

Implementors