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Diffstat (limited to 'lib/xxhash.c')
| -rw-r--r-- | lib/xxhash.c | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/lib/xxhash.c b/lib/xxhash.c new file mode 100644 index 0000000..aa61e2a --- /dev/null +++ b/lib/xxhash.c @@ -0,0 +1,500 @@ +/* + * 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: http://cyan4973.github.io/xxHash/ + * - xxHash source repository: https://github.com/Cyan4973/xxHash + */ + +#include <asm/unaligned.h> +#include <linux/errno.h> +#include <linux/compiler.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/xxhash.h> + +/*-************************************* + * Macros + **************************************/ +#define xxh_rotl32(x, r) ((x << r) | (x >> (32 - r))) +#define xxh_rotl64(x, r) ((x << r) | (x >> (64 - 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; + +static const uint64_t PRIME64_1 = 11400714785074694791ULL; +static const uint64_t PRIME64_2 = 14029467366897019727ULL; +static const uint64_t PRIME64_3 = 1609587929392839161ULL; +static const uint64_t PRIME64_4 = 9650029242287828579ULL; +static const uint64_t PRIME64_5 = 2870177450012600261ULL; + +/*-************************** + * Utils + ***************************/ +void xxh32_copy_state(struct xxh32_state *dst, const struct xxh32_state *src) +{ + memcpy(dst, src, sizeof(*dst)); +} +EXPORT_SYMBOL(xxh32_copy_state); + +void xxh64_copy_state(struct xxh64_state *dst, const struct xxh64_state *src) +{ + memcpy(dst, src, sizeof(*dst)); +} +EXPORT_SYMBOL(xxh64_copy_state); + +/*-*************************** + * 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; +} +EXPORT_SYMBOL(xxh32); + +static uint64_t xxh64_round(uint64_t acc, const uint64_t input) +{ + acc += input * PRIME64_2; + acc = xxh_rotl64(acc, 31); + acc *= PRIME64_1; + return acc; +} + +static uint64_t xxh64_merge_round(uint64_t acc, uint64_t val) +{ + val = xxh64_round(0, val); + acc ^= val; + acc = acc * PRIME64_1 + PRIME64_4; + return acc; +} + +uint64_t xxh64(const void *input, const size_t len, const uint64_t seed) +{ + const uint8_t *p = (const uint8_t *)input; + const uint8_t *const b_end = p + len; + uint64_t h64; + + if (len >= 32) { + const uint8_t *const limit = b_end - 32; + uint64_t v1 = seed + PRIME64_1 + PRIME64_2; + uint64_t v2 = seed + PRIME64_2; + uint64_t v3 = seed + 0; + uint64_t v4 = seed - PRIME64_1; + + do { + v1 = xxh64_round(v1, get_unaligned_le64(p)); + p += 8; + v2 = xxh64_round(v2, get_unaligned_le64(p)); + p += 8; + v3 = xxh64_round(v3, get_unaligned_le64(p)); + p += 8; + v4 = xxh64_round(v4, get_unaligned_le64(p)); + p += 8; + } while (p <= limit); + + h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) + + xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18); + h64 = xxh64_merge_round(h64, v1); + h64 = xxh64_merge_round(h64, v2); + h64 = xxh64_merge_round(h64, v3); + h64 = xxh64_merge_round(h64, v4); + + } else { + h64 = seed + PRIME64_5; + } + + h64 += (uint64_t)len; + + while (p + 8 <= b_end) { + const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p)); + + h64 ^= k1; + h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4; + p += 8; + } + + if (p + 4 <= b_end) { + h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1; + h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3; + p += 4; + } + + while (p < b_end) { + h64 ^= (*p) * PRIME64_5; + h64 = xxh_rotl64(h64, 11) * PRIME64_1; + p++; + } + + h64 ^= h64 >> 33; + h64 *= PRIME64_2; + h64 ^= h64 >> 29; + h64 *= PRIME64_3; + h64 ^= h64 >> 32; + + return h64; +} +EXPORT_SYMBOL(xxh64); + +/*-************************************************** + * 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)); +} +EXPORT_SYMBOL(xxh32_reset); + +void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed) +{ + /* use a local state for memcpy() to avoid strict-aliasing warnings */ + struct xxh64_state state; + + memset(&state, 0, sizeof(state)); + state.v1 = seed + PRIME64_1 + PRIME64_2; + state.v2 = seed + PRIME64_2; + state.v3 = seed + 0; + state.v4 = seed - PRIME64_1; + memcpy(statePtr, &state, sizeof(state)); +} +EXPORT_SYMBOL(xxh64_reset); + +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; +} +EXPORT_SYMBOL(xxh32_update); + +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; +} +EXPORT_SYMBOL(xxh32_digest); + +int xxh64_update(struct xxh64_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 += len; + + if (state->memsize + len < 32) { /* fill in tmp buffer */ + memcpy(((uint8_t *)state->mem64) + state->memsize, input, len); + state->memsize += (uint32_t)len; + return 0; + } + + if (state->memsize) { /* tmp buffer is full */ + uint64_t *p64 = state->mem64; + + memcpy(((uint8_t *)p64) + state->memsize, input, + 32 - state->memsize); + + state->v1 = xxh64_round(state->v1, get_unaligned_le64(p64)); + p64++; + state->v2 = xxh64_round(state->v2, get_unaligned_le64(p64)); + p64++; + state->v3 = xxh64_round(state->v3, get_unaligned_le64(p64)); + p64++; + state->v4 = xxh64_round(state->v4, get_unaligned_le64(p64)); + + p += 32 - state->memsize; + state->memsize = 0; + } + + if (p + 32 <= b_end) { + const uint8_t *const limit = b_end - 32; + uint64_t v1 = state->v1; + uint64_t v2 = state->v2; + uint64_t v3 = state->v3; + uint64_t v4 = state->v4; + + do { + v1 = xxh64_round(v1, get_unaligned_le64(p)); + p += 8; + v2 = xxh64_round(v2, get_unaligned_le64(p)); + p += 8; + v3 = xxh64_round(v3, get_unaligned_le64(p)); + p += 8; + v4 = xxh64_round(v4, get_unaligned_le64(p)); + p += 8; + } while (p <= limit); + + state->v1 = v1; + state->v2 = v2; + state->v3 = v3; + state->v4 = v4; + } + + if (p < b_end) { + memcpy(state->mem64, p, (size_t)(b_end-p)); + state->memsize = (uint32_t)(b_end - p); + } + + return 0; +} +EXPORT_SYMBOL(xxh64_update); + +uint64_t xxh64_digest(const struct xxh64_state *state) +{ + const uint8_t *p = (const uint8_t *)state->mem64; + const uint8_t *const b_end = (const uint8_t *)state->mem64 + + state->memsize; + uint64_t h64; + + if (state->total_len >= 32) { + const uint64_t v1 = state->v1; + const uint64_t v2 = state->v2; + const uint64_t v3 = state->v3; + const uint64_t v4 = state->v4; + + h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) + + xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18); + h64 = xxh64_merge_round(h64, v1); + h64 = xxh64_merge_round(h64, v2); + h64 = xxh64_merge_round(h64, v3); + h64 = xxh64_merge_round(h64, v4); + } else { + h64 = state->v3 + PRIME64_5; + } + + h64 += (uint64_t)state->total_len; + + while (p + 8 <= b_end) { + const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p)); + + h64 ^= k1; + h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4; + p += 8; + } + + if (p + 4 <= b_end) { + h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1; + h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3; + p += 4; + } + + while (p < b_end) { + h64 ^= (*p) * PRIME64_5; + h64 = xxh_rotl64(h64, 11) * PRIME64_1; + p++; + } + + h64 ^= h64 >> 33; + h64 *= PRIME64_2; + h64 ^= h64 >> 29; + h64 *= PRIME64_3; + h64 ^= h64 >> 32; + + return h64; +} +EXPORT_SYMBOL(xxh64_digest); + +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_DESCRIPTION("xxHash"); |
