wpi::hashing::detail::hash_state Struct Reference

The intermediate state used during hashing. More...

#include <wpi/Hashing.h>

Public Member Functions
void	mix (const char *s)
	Mix in a 64-byte buffer of data.
uint64_t	finalize (size_t length)
	Compute the final 64-bit hash code value based on the current state and the length of bytes hashed.

Static Public Member Functions
static hash_state	create (const char *s, uint64_t seed)
	Create a new hash_state structure and initialize it based on the seed and the first 64-byte chunk.
static void	mix_32_bytes (const char *s, uint64_t &a, uint64_t &b)
	Mix 32-bytes from the input sequence into the 16-bytes of 'a' and 'b', including whatever is already in 'a' and 'b'.

Public Attributes
uint64_t	h0 = 0
uint64_t	h1 = 0
uint64_t	h2 = 0
uint64_t	h3 = 0
uint64_t	h4 = 0
uint64_t	h5 = 0
uint64_t	h6 = 0

Detailed Description

The intermediate state used during hashing.

Currently, the algorithm for computing hash codes is based on CityHash and keeps 56 bytes of arbitrary state.

Member Function Documentation

create()

static hash_state wpi::hashing::detail::hash_state::create ( const char * s, uint64_t seed )

inlinestatic

Create a new hash_state structure and initialize it based on the seed and the first 64-byte chunk.

This effectively performs the initial mix.

finalize()

uint64_t wpi::hashing::detail::hash_state::finalize ( size_t length )

inline

Compute the final 64-bit hash code value based on the current state and the length of bytes hashed.

mix()

void wpi::hashing::detail::hash_state::mix ( const char * s )

inline

Mix in a 64-byte buffer of data.

We mix all 64 bytes even when the chunk length is smaller, but we record the actual length.

mix_32_bytes()

static void wpi::hashing::detail::hash_state::mix_32_bytes ( const char * s, uint64_t & a, uint64_t & b )

inlinestatic

Mix 32-bytes from the input sequence into the 16-bytes of 'a' and 'b', including whatever is already in 'a' and 'b'.

Member Data Documentation

h0

uint64_t wpi::hashing::detail::hash_state::h0 = 0

h1

uint64_t wpi::hashing::detail::hash_state::h1 = 0

h2

uint64_t wpi::hashing::detail::hash_state::h2 = 0

h3

uint64_t wpi::hashing::detail::hash_state::h3 = 0

h4

uint64_t wpi::hashing::detail::hash_state::h4 = 0

h5

uint64_t wpi::hashing::detail::hash_state::h5 = 0

h6

uint64_t wpi::hashing::detail::hash_state::h6 = 0

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The documentation for this struct was generated from the following file:

• wpi/Hashing.h