Struct HasherFx

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

A hashing algorithm used in the Rustc compiler, implemented for u32, u64 & usize.

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.

Vendored

This is adapted work from fxhash.

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

Computes a hash of a byte slice using the default seed.

Equivalent to calling Self::hash_bytes_with_seed with 0.

pub const fn hash_bytes_with_seed(seed: u32, v: &[u8]) -> u32

Computes a hash of a byte slice using a custom seed.

This allows deterministic but varied hashing for different use cases.

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

Computes a hash of a byte slice using the default seed.

Equivalent to calling Self::hash_bytes_with_seed with 0.

pub const fn hash_bytes_with_seed(seed: u64, v: &[u8]) -> u64

Computes a hash of a byte slice using a custom seed.

This allows deterministic but varied hashing for different use cases.

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

Computes a hash of a byte slice using the default seed.

Equivalent to calling Self::hash_bytes_with_seed with 0.

pub const fn hash_bytes_with_seed(seed: usize, v: &[u8]) -> usize

Computes a hash of a byte slice using a custom seed.

This allows deterministic but varied hashing for different use cases.

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>