Struct PartialFNVHash

pub struct PartialFNVHash(/* private fields */);

Hasher which computes the lowest 6 bits of a 32-bit FNV-1 variant.

This variant of FNV-1 hash has the regular prime constant of 0x01000193 but has a different initial state: 0x28021967 (in contrast to regular FNV-1-32’s 0x811c9dc5).

Since ssdeep only uses the lowest 6 bits of the hash value, it ignores any higher bits, enabling updating the state table-based (instead of multiply and xor) unless the opt-reduce-fnv-table feature is enabled.

Compatibility Notice

This type is going to be completely private on the next major release. If you need to experiment with internal hashing functions, just vendor the source code for your needs.

Implementations

impl PartialFNVHash

pub fn new() -> Self

Creates a new PartialFNVHash with the initial value.

pub fn update_by_byte(&mut self, ch: u8) -> &mut Self

Updates the hash value by processing a byte.

pub fn update_by_iter(&mut self, iter: impl Iterator<Item = u8>) -> &mut Self

Updates the hash value by processing an iterator of u8.

pub fn update(&mut self, buf: &[u8]) -> &mut Self

Updates the hash value by processing a slice of u8.

pub fn value(&self) -> u8

Returns the current hash value.

Note that there’s no “finalization” on the FNV hash. You can even continue updating after reading the hash value.

Trait Implementations

impl AddAssign<&[u8]> for PartialFNVHash

fn add_assign(&mut self, buffer: &[u8])

Updates the hash value by processing a slice of u8.

impl<const N: usize> AddAssign<&[u8; N]> for PartialFNVHash

fn add_assign(&mut self, buffer: &[u8; N])

Updates the hash value by processing an array of u8.

impl AddAssign<u8> for PartialFNVHash

fn add_assign(&mut self, byte: u8)

Updates the hash value by processing a byte.

impl Clone for PartialFNVHash

fn clone(&self) -> PartialFNVHash

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for PartialFNVHash

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

Formats the value using the given formatter.

impl Default for PartialFNVHash

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for PartialFNVHash

fn eq(&self, other: &PartialFNVHash) -> 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 Copy for PartialFNVHash

impl Eq for PartialFNVHash

impl StructuralPartialEq for PartialFNVHash