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/*
* xxHash - Extremely Fast Hash algorithm
* Copyright (C) 2012-2016, Yann Collet.
*
* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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.
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License version 2 as published by the
* Free Software Foundation. This program is dual-licensed; you may select
* either version 2 of the GNU General Public License ("GPL") or BSD license
* ("BSD").
*
* You can contact the author at:
* - xxHash homepage: https://cyan4973.github.io/xxHash/
* - xxHash source repository: https://github.com/Cyan4973/xxHash
*/
#include <xen/compiler.h>
#include <xen/errno.h>
#include <xen/string.h>
#include <xen/xxhash.h>
#include <asm/unaligned.h>
/*-*************************************
* Macros
**************************************/
#define xxh_rotl32(x, r) ((x << r) | (x >> (32 - r)))
#ifdef __LITTLE_ENDIAN
# define XXH_CPU_LITTLE_ENDIAN 1
#else
# define XXH_CPU_LITTLE_ENDIAN 0
#endif
/*-*************************************
* Constants
**************************************/
static const uint32_t PRIME32_1 = 2654435761U;
static const uint32_t PRIME32_2 = 2246822519U;
static const uint32_t PRIME32_3 = 3266489917U;
static const uint32_t PRIME32_4 = 668265263U;
static const uint32_t PRIME32_5 = 374761393U;
/*-**************************
* Utils
***************************/
void xxh32_copy_state(struct xxh32_state *dst, const struct xxh32_state *src)
{
memcpy(dst, src, sizeof(*dst));
}
/*-***************************
* Simple Hash Functions
****************************/
static uint32_t xxh32_round(uint32_t seed, const uint32_t input)
{
seed += input * PRIME32_2;
seed = xxh_rotl32(seed, 13);
seed *= PRIME32_1;
return seed;
}
uint32_t xxh32(const void *input, const size_t len, const uint32_t seed)
{
const uint8_t *p = (const uint8_t *)input;
const uint8_t *b_end = p + len;
uint32_t h32;
if (len >= 16) {
const uint8_t *const limit = b_end - 16;
uint32_t v1 = seed + PRIME32_1 + PRIME32_2;
uint32_t v2 = seed + PRIME32_2;
uint32_t v3 = seed + 0;
uint32_t v4 = seed - PRIME32_1;
do {
v1 = xxh32_round(v1, get_unaligned_le32(p));
p += 4;
v2 = xxh32_round(v2, get_unaligned_le32(p));
p += 4;
v3 = xxh32_round(v3, get_unaligned_le32(p));
p += 4;
v4 = xxh32_round(v4, get_unaligned_le32(p));
p += 4;
} while (p <= limit);
h32 = xxh_rotl32(v1, 1) + xxh_rotl32(v2, 7) +
xxh_rotl32(v3, 12) + xxh_rotl32(v4, 18);
} else {
h32 = seed + PRIME32_5;
}
h32 += (uint32_t)len;
while (p + 4 <= b_end) {
h32 += get_unaligned_le32(p) * PRIME32_3;
h32 = xxh_rotl32(h32, 17) * PRIME32_4;
p += 4;
}
while (p < b_end) {
h32 += (*p) * PRIME32_5;
h32 = xxh_rotl32(h32, 11) * PRIME32_1;
p++;
}
h32 ^= h32 >> 15;
h32 *= PRIME32_2;
h32 ^= h32 >> 13;
h32 *= PRIME32_3;
h32 ^= h32 >> 16;
return h32;
}
/*-**************************************************
* Advanced Hash Functions
***************************************************/
void xxh32_reset(struct xxh32_state *statePtr, const uint32_t seed)
{
/* use a local state for memcpy() to avoid strict-aliasing warnings */
struct xxh32_state state;
memset(&state, 0, sizeof(state));
state.v1 = seed + PRIME32_1 + PRIME32_2;
state.v2 = seed + PRIME32_2;
state.v3 = seed + 0;
state.v4 = seed - PRIME32_1;
memcpy(statePtr, &state, sizeof(state));
}
int xxh32_update(struct xxh32_state *state, const void *input, const size_t len)
{
const uint8_t *p = (const uint8_t *)input;
const uint8_t *const b_end = p + len;
if (input == NULL)
return -EINVAL;
state->total_len_32 += (uint32_t)len;
state->large_len |= (len >= 16) | (state->total_len_32 >= 16);
if (state->memsize + len < 16) { /* fill in tmp buffer */
memcpy((uint8_t *)(state->mem32) + state->memsize, input, len);
state->memsize += (uint32_t)len;
return 0;
}
if (state->memsize) { /* some data left from previous update */
const uint32_t *p32 = state->mem32;
memcpy((uint8_t *)(state->mem32) + state->memsize, input,
16 - state->memsize);
state->v1 = xxh32_round(state->v1, get_unaligned_le32(p32));
p32++;
state->v2 = xxh32_round(state->v2, get_unaligned_le32(p32));
p32++;
state->v3 = xxh32_round(state->v3, get_unaligned_le32(p32));
p32++;
state->v4 = xxh32_round(state->v4, get_unaligned_le32(p32));
p32++;
p += 16-state->memsize;
state->memsize = 0;
}
if (p <= b_end - 16) {
const uint8_t *const limit = b_end - 16;
uint32_t v1 = state->v1;
uint32_t v2 = state->v2;
uint32_t v3 = state->v3;
uint32_t v4 = state->v4;
do {
v1 = xxh32_round(v1, get_unaligned_le32(p));
p += 4;
v2 = xxh32_round(v2, get_unaligned_le32(p));
p += 4;
v3 = xxh32_round(v3, get_unaligned_le32(p));
p += 4;
v4 = xxh32_round(v4, get_unaligned_le32(p));
p += 4;
} while (p <= limit);
state->v1 = v1;
state->v2 = v2;
state->v3 = v3;
state->v4 = v4;
}
if (p < b_end) {
memcpy(state->mem32, p, (size_t)(b_end-p));
state->memsize = (uint32_t)(b_end-p);
}
return 0;
}
uint32_t xxh32_digest(const struct xxh32_state *state)
{
const uint8_t *p = (const uint8_t *)state->mem32;
const uint8_t *const b_end = (const uint8_t *)(state->mem32) +
state->memsize;
uint32_t h32;
if (state->large_len) {
h32 = xxh_rotl32(state->v1, 1) + xxh_rotl32(state->v2, 7) +
xxh_rotl32(state->v3, 12) + xxh_rotl32(state->v4, 18);
} else {
h32 = state->v3 /* == seed */ + PRIME32_5;
}
h32 += state->total_len_32;
while (p + 4 <= b_end) {
h32 += get_unaligned_le32(p) * PRIME32_3;
h32 = xxh_rotl32(h32, 17) * PRIME32_4;
p += 4;
}
while (p < b_end) {
h32 += (*p) * PRIME32_5;
h32 = xxh_rotl32(h32, 11) * PRIME32_1;
p++;
}
h32 ^= h32 >> 15;
h32 *= PRIME32_2;
h32 ^= h32 >> 13;
h32 *= PRIME32_3;
h32 ^= h32 >> 16;
return h32;
}
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