cryb-to/lib/hash/cryb_fnv.c
2022-05-15 18:27:01 +02:00

113 lines
2.8 KiB
C

/*-
* Copyright (c) 2022 Dag-Erling Smørgrav
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "cryb/impl.h"
#include <stddef.h>
#include <stdint.h>
#include <cryb/hash.h>
#include "cryb_fnv_impl.h"
/*
* Implementations of the 32- and 64-bit Fowler-Noll-Vo (FNV) 0, 1, and 1a hashes.
*/
uint32_t fnv0_32_hash(const void *data, size_t len)
{
const uint8_t *p;
uint32_t h;
for (p = data, h = 0; len > 0; ++p, --len) {
h *= FNV_32_PRIME;
h ^= *p;
}
return (h);
}
uint64_t fnv0_64_hash(const void *data, size_t len)
{
const uint8_t *p;
uint64_t h;
for (p = data, h = 0; len > 0; ++p, --len) {
h *= FNV_64_PRIME;
h ^= *p;
}
return (h);
}
uint32_t fnv1_32_hash(const void *data, size_t len)
{
const uint8_t *p;
uint32_t h;
for (p = data, h = FNV_32_OFFSET_BASIS; len > 0; ++p, --len) {
h *= FNV_32_PRIME;
h ^= *p;
}
return (h);
}
uint64_t fnv1_64_hash(const void *data, size_t len)
{
const uint8_t *p;
uint64_t h;
for (p = data, h = FNV_64_OFFSET_BASIS; len > 0; ++p, --len) {
h *= FNV_64_PRIME;
h ^= *p;
}
return (h);
}
uint32_t fnv1a_32_hash(const void *data, size_t len)
{
const uint8_t *p;
uint32_t h;
for (p = data, h = FNV_32_OFFSET_BASIS; len > 0; ++p, --len) {
h ^= *p;
h *= FNV_32_PRIME;
}
return (h);
}
uint64_t fnv1a_64_hash(const void *data, size_t len)
{
const uint8_t *p;
uint64_t h;
for (p = data, h = FNV_64_OFFSET_BASIS; len > 0; ++p, --len) {
h ^= *p;
h *= FNV_64_PRIME;
}
return (h);
}