Struct HasherFx

pub struct HasherFx<T> { /* private fields */ }

Available on crate feature hash only.

This hashing algorithm was extracted from the Rustc compiler.

This is the same hashing algorithm used for some internal operations in Firefox. The strength of this algorithm is in hashing 4 bytes at a time on any platform, where the FNV algorithm works on one byte at a time.

This hashing algorithm should not be used for cryptographic, or in scenarios where DoS attacks are a concern.

It’s implemented for u32, u64 and usize.

Derived Work

This is derived work from the fxhash crate, including the following modifications:

• join all structs in a single HasherFx const-generic.
• implement the standalone functions as methods.
• make it no_std compatible.
• remove byteorder dependency.
• add const methods for hashing byte slices.
• rename the structures.
• misc. refactoring.

Implementations

impl HasherFx<u32>

pub const fn new() -> Self

Returns a default Fx hasher.

pub const fn with_seed(seed: u32) -> Self

Returns a new Fx hasher with the given seed.

pub fn hash<T: Hash + ?Sized>(v: &T) -> u32

A convenience method for when you need a quick hash.

pub const fn hash_bytes(v: &[u8]) -> u32

A const method for when you need a hash of a byte slice.

impl HasherFx<u64>

pub const fn new() -> Self

Returns a default Fx hasher.

pub const fn with_seed(seed: u64) -> Self

Returns a new Fx hasher with the given seed.

pub fn hash<T: Hash + ?Sized>(v: &T) -> u64

A convenience method for when you need a quick hash.

pub const fn hash_bytes(v: &[u8]) -> u64

A const method for when you need a hash of a byte slice.

impl HasherFx<usize>

pub const fn new() -> Self

Returns a default Fx hasher.

pub const fn with_seed(seed: usize) -> Self

Returns a new Fx hasher with the given seed.

pub fn hash<T: Hash + ?Sized>(v: &T) -> usize

A convenience method for when you need a quick hash.

pub const fn hash_bytes(v: &[u8]) -> usize

A const method for when you need a hash of a byte slice.

Trait Implementations

impl<T: Clone> Clone for HasherFx<T>

fn clone(&self) -> HasherFx<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl ConstDefault for HasherFx<u32>

const DEFAULT: Self

Returns the compile-time “default value” for a type.

impl ConstDefault for HasherFx<u64>

const DEFAULT: Self

Returns the compile-time “default value” for a type.

impl ConstDefault for HasherFx<usize>

const DEFAULT: Self

Returns the compile-time “default value” for a type.

impl<T: Debug> Debug for HasherFx<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for HasherFx<u32>

fn default() -> Self

Returns the “default value” for a type.

impl Default for HasherFx<u64>

fn default() -> Self

Returns the “default value” for a type.

impl Default for HasherFx<usize>

fn default() -> Self

Returns the “default value” for a type.

impl Hasher for HasherFx<u32>

fn write(&mut self, bytes: &[u8])

Writes some data into this Hasher.

fn write_u8(&mut self, i: u8)

Writes a single u8 into this hasher.

fn write_u16(&mut self, i: u16)

Writes a single u16 into this hasher.

fn write_u32(&mut self, i: u32)

Writes a single u32 into this hasher.

fn write_u64(&mut self, i: u64)

Writes a single u64 into this hasher.

fn write_usize(&mut self, i: usize)

Writes a single usize into this hasher.

fn finish(&self) -> u64

Returns the hash value for the values written so far.

fn write_u128(&mut self, i: u128)

Writes a single u128 into this hasher.

fn write_i8(&mut self, i: i8)

Writes a single i8 into this hasher.

fn write_i16(&mut self, i: i16)

Writes a single i16 into this hasher.

fn write_i32(&mut self, i: i32)

Writes a single i32 into this hasher.

fn write_i64(&mut self, i: i64)

Writes a single i64 into this hasher.

fn write_i128(&mut self, i: i128)

Writes a single i128 into this hasher.

fn write_isize(&mut self, i: isize)

Writes a single isize into this hasher.

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.

fn write_str(&mut self, s: &str)

🔬This is a nightly-only experimental API. (hasher_prefixfree_extras)

Writes a single str into this hasher.

impl Hasher for HasherFx<u64>

fn write(&mut self, bytes: &[u8])

Writes some data into this Hasher.

fn write_u8(&mut self, i: u8)

Writes a single u8 into this hasher.

fn write_u16(&mut self, i: u16)

Writes a single u16 into this hasher.

fn write_u32(&mut self, i: u32)

Writes a single u32 into this hasher.

fn write_u64(&mut self, i: u64)

Writes a single u64 into this hasher.

fn write_usize(&mut self, i: usize)

Writes a single usize into this hasher.

fn finish(&self) -> u64

Returns the hash value for the values written so far.

fn write_u128(&mut self, i: u128)

Writes a single u128 into this hasher.

fn write_i8(&mut self, i: i8)

Writes a single i8 into this hasher.

fn write_i16(&mut self, i: i16)

Writes a single i16 into this hasher.

fn write_i32(&mut self, i: i32)

Writes a single i32 into this hasher.

fn write_i64(&mut self, i: i64)

Writes a single i64 into this hasher.

fn write_i128(&mut self, i: i128)

Writes a single i128 into this hasher.

fn write_isize(&mut self, i: isize)

Writes a single isize into this hasher.

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.

fn write_str(&mut self, s: &str)

🔬This is a nightly-only experimental API. (hasher_prefixfree_extras)

Writes a single str into this hasher.

impl Hasher for HasherFx<usize>

fn write(&mut self, bytes: &[u8])

Writes some data into this Hasher.

fn write_u8(&mut self, i: u8)

Writes a single u8 into this hasher.

fn write_u16(&mut self, i: u16)

Writes a single u16 into this hasher.

fn write_u32(&mut self, i: u32)

Writes a single u32 into this hasher.

fn write_u64(&mut self, i: u64)

Writes a single u64 into this hasher.

fn write_usize(&mut self, i: usize)

Writes a single usize into this hasher.

fn finish(&self) -> u64

Returns the hash value for the values written so far.

fn write_u128(&mut self, i: u128)

Writes a single u128 into this hasher.

fn write_i8(&mut self, i: i8)

Writes a single i8 into this hasher.

fn write_i16(&mut self, i: i16)

Writes a single i16 into this hasher.

fn write_i32(&mut self, i: i32)

Writes a single i32 into this hasher.

fn write_i64(&mut self, i: i64)

Writes a single i64 into this hasher.

fn write_i128(&mut self, i: i128)

Writes a single i128 into this hasher.

fn write_isize(&mut self, i: isize)

Writes a single isize into this hasher.

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.

fn write_str(&mut self, s: &str)

🔬This is a nightly-only experimental API. (hasher_prefixfree_extras)

Writes a single str into this hasher.

impl<T: PartialEq> PartialEq for HasherFx<T>

fn eq(&self, other: &HasherFx<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: Copy> Copy for HasherFx<T>

impl<T: Eq> Eq for HasherFx<T>

impl<T> StructuralPartialEq for HasherFx<T>