1 /* 2 * xxHash - Extremely Fast Hash algorithm 3 * Copyright (C) 2012-2016, Yann Collet. 4 * 5 * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions are 9 * met: 10 * 11 * * Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * * Redistributions in binary form must reproduce the above 14 * copyright notice, this list of conditions and the following disclaimer 15 * in the documentation and/or other materials provided with the 16 * distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * This program is free software; you can redistribute it and/or modify it under 31 * the terms of the GNU General Public License version 2 as published by the 32 * Free Software Foundation. This program is dual-licensed; you may select 33 * either version 2 of the GNU General Public License ("GPL") or BSD license 34 * ("BSD"). 35 * 36 * You can contact the author at: 37 * - xxHash homepage: https://cyan4973.github.io/xxHash/ 38 * - xxHash source repository: https://github.com/Cyan4973/xxHash 39 */ 40 41 #include <linux/unaligned.h> 42 #include <linux/errno.h> 43 #include <linux/compiler.h> 44 #include <linux/kernel.h> 45 #include <linux/module.h> 46 #include <linux/string.h> 47 #include <linux/xxhash.h> 48 49 /*-************************************* 50 * Macros 51 **************************************/ 52 #define xxh_rotl32(x, r) ((x << r) | (x >> (32 - r))) 53 #define xxh_rotl64(x, r) ((x << r) | (x >> (64 - r))) 54 55 #ifdef __LITTLE_ENDIAN 56 # define XXH_CPU_LITTLE_ENDIAN 1 57 #else 58 # define XXH_CPU_LITTLE_ENDIAN 0 59 #endif 60 61 /*-************************************* 62 * Constants 63 **************************************/ 64 static const uint32_t PRIME32_1 = 2654435761U; 65 static const uint32_t PRIME32_2 = 2246822519U; 66 static const uint32_t PRIME32_3 = 3266489917U; 67 static const uint32_t PRIME32_4 = 668265263U; 68 static const uint32_t PRIME32_5 = 374761393U; 69 70 static const uint64_t PRIME64_1 = 11400714785074694791ULL; 71 static const uint64_t PRIME64_2 = 14029467366897019727ULL; 72 static const uint64_t PRIME64_3 = 1609587929392839161ULL; 73 static const uint64_t PRIME64_4 = 9650029242287828579ULL; 74 static const uint64_t PRIME64_5 = 2870177450012600261ULL; 75 76 /*-*************************** 77 * Simple Hash Functions 78 ****************************/ 79 static uint32_t xxh32_round(uint32_t seed, const uint32_t input) 80 { 81 seed += input * PRIME32_2; 82 seed = xxh_rotl32(seed, 13); 83 seed *= PRIME32_1; 84 return seed; 85 } 86 87 uint32_t xxh32(const void *input, const size_t len, const uint32_t seed) 88 { 89 const uint8_t *p = (const uint8_t *)input; 90 const uint8_t *b_end = p + len; 91 uint32_t h32; 92 93 if (len >= 16) { 94 const uint8_t *const limit = b_end - 16; 95 uint32_t v1 = seed + PRIME32_1 + PRIME32_2; 96 uint32_t v2 = seed + PRIME32_2; 97 uint32_t v3 = seed + 0; 98 uint32_t v4 = seed - PRIME32_1; 99 100 do { 101 v1 = xxh32_round(v1, get_unaligned_le32(p)); 102 p += 4; 103 v2 = xxh32_round(v2, get_unaligned_le32(p)); 104 p += 4; 105 v3 = xxh32_round(v3, get_unaligned_le32(p)); 106 p += 4; 107 v4 = xxh32_round(v4, get_unaligned_le32(p)); 108 p += 4; 109 } while (p <= limit); 110 111 h32 = xxh_rotl32(v1, 1) + xxh_rotl32(v2, 7) + 112 xxh_rotl32(v3, 12) + xxh_rotl32(v4, 18); 113 } else { 114 h32 = seed + PRIME32_5; 115 } 116 117 h32 += (uint32_t)len; 118 119 while (p + 4 <= b_end) { 120 h32 += get_unaligned_le32(p) * PRIME32_3; 121 h32 = xxh_rotl32(h32, 17) * PRIME32_4; 122 p += 4; 123 } 124 125 while (p < b_end) { 126 h32 += (*p) * PRIME32_5; 127 h32 = xxh_rotl32(h32, 11) * PRIME32_1; 128 p++; 129 } 130 131 h32 ^= h32 >> 15; 132 h32 *= PRIME32_2; 133 h32 ^= h32 >> 13; 134 h32 *= PRIME32_3; 135 h32 ^= h32 >> 16; 136 137 return h32; 138 } 139 EXPORT_SYMBOL(xxh32); 140 141 static uint64_t xxh64_round(uint64_t acc, const uint64_t input) 142 { 143 acc += input * PRIME64_2; 144 acc = xxh_rotl64(acc, 31); 145 acc *= PRIME64_1; 146 return acc; 147 } 148 149 static uint64_t xxh64_merge_round(uint64_t acc, uint64_t val) 150 { 151 val = xxh64_round(0, val); 152 acc ^= val; 153 acc = acc * PRIME64_1 + PRIME64_4; 154 return acc; 155 } 156 157 uint64_t xxh64(const void *input, const size_t len, const uint64_t seed) 158 { 159 const uint8_t *p = (const uint8_t *)input; 160 const uint8_t *const b_end = p + len; 161 uint64_t h64; 162 163 if (len >= 32) { 164 const uint8_t *const limit = b_end - 32; 165 uint64_t v1 = seed + PRIME64_1 + PRIME64_2; 166 uint64_t v2 = seed + PRIME64_2; 167 uint64_t v3 = seed + 0; 168 uint64_t v4 = seed - PRIME64_1; 169 170 do { 171 v1 = xxh64_round(v1, get_unaligned_le64(p)); 172 p += 8; 173 v2 = xxh64_round(v2, get_unaligned_le64(p)); 174 p += 8; 175 v3 = xxh64_round(v3, get_unaligned_le64(p)); 176 p += 8; 177 v4 = xxh64_round(v4, get_unaligned_le64(p)); 178 p += 8; 179 } while (p <= limit); 180 181 h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) + 182 xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18); 183 h64 = xxh64_merge_round(h64, v1); 184 h64 = xxh64_merge_round(h64, v2); 185 h64 = xxh64_merge_round(h64, v3); 186 h64 = xxh64_merge_round(h64, v4); 187 188 } else { 189 h64 = seed + PRIME64_5; 190 } 191 192 h64 += (uint64_t)len; 193 194 while (p + 8 <= b_end) { 195 const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p)); 196 197 h64 ^= k1; 198 h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4; 199 p += 8; 200 } 201 202 if (p + 4 <= b_end) { 203 h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1; 204 h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3; 205 p += 4; 206 } 207 208 while (p < b_end) { 209 h64 ^= (*p) * PRIME64_5; 210 h64 = xxh_rotl64(h64, 11) * PRIME64_1; 211 p++; 212 } 213 214 h64 ^= h64 >> 33; 215 h64 *= PRIME64_2; 216 h64 ^= h64 >> 29; 217 h64 *= PRIME64_3; 218 h64 ^= h64 >> 32; 219 220 return h64; 221 } 222 EXPORT_SYMBOL(xxh64); 223 224 /*-************************************************** 225 * Advanced Hash Functions 226 ***************************************************/ 227 void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed) 228 { 229 /* use a local state for memcpy() to avoid strict-aliasing warnings */ 230 struct xxh64_state state; 231 232 memset(&state, 0, sizeof(state)); 233 state.v1 = seed + PRIME64_1 + PRIME64_2; 234 state.v2 = seed + PRIME64_2; 235 state.v3 = seed + 0; 236 state.v4 = seed - PRIME64_1; 237 memcpy(statePtr, &state, sizeof(state)); 238 } 239 EXPORT_SYMBOL(xxh64_reset); 240 241 int xxh64_update(struct xxh64_state *state, const void *input, const size_t len) 242 { 243 const uint8_t *p = (const uint8_t *)input; 244 const uint8_t *const b_end = p + len; 245 246 if (input == NULL) 247 return -EINVAL; 248 249 state->total_len += len; 250 251 if (state->memsize + len < 32) { /* fill in tmp buffer */ 252 memcpy(((uint8_t *)state->mem64) + state->memsize, input, len); 253 state->memsize += (uint32_t)len; 254 return 0; 255 } 256 257 if (state->memsize) { /* tmp buffer is full */ 258 uint64_t *p64 = state->mem64; 259 260 memcpy(((uint8_t *)p64) + state->memsize, input, 261 32 - state->memsize); 262 263 state->v1 = xxh64_round(state->v1, get_unaligned_le64(p64)); 264 p64++; 265 state->v2 = xxh64_round(state->v2, get_unaligned_le64(p64)); 266 p64++; 267 state->v3 = xxh64_round(state->v3, get_unaligned_le64(p64)); 268 p64++; 269 state->v4 = xxh64_round(state->v4, get_unaligned_le64(p64)); 270 271 p += 32 - state->memsize; 272 state->memsize = 0; 273 } 274 275 if (p + 32 <= b_end) { 276 const uint8_t *const limit = b_end - 32; 277 uint64_t v1 = state->v1; 278 uint64_t v2 = state->v2; 279 uint64_t v3 = state->v3; 280 uint64_t v4 = state->v4; 281 282 do { 283 v1 = xxh64_round(v1, get_unaligned_le64(p)); 284 p += 8; 285 v2 = xxh64_round(v2, get_unaligned_le64(p)); 286 p += 8; 287 v3 = xxh64_round(v3, get_unaligned_le64(p)); 288 p += 8; 289 v4 = xxh64_round(v4, get_unaligned_le64(p)); 290 p += 8; 291 } while (p <= limit); 292 293 state->v1 = v1; 294 state->v2 = v2; 295 state->v3 = v3; 296 state->v4 = v4; 297 } 298 299 if (p < b_end) { 300 memcpy(state->mem64, p, (size_t)(b_end-p)); 301 state->memsize = (uint32_t)(b_end - p); 302 } 303 304 return 0; 305 } 306 EXPORT_SYMBOL(xxh64_update); 307 308 uint64_t xxh64_digest(const struct xxh64_state *state) 309 { 310 const uint8_t *p = (const uint8_t *)state->mem64; 311 const uint8_t *const b_end = (const uint8_t *)state->mem64 + 312 state->memsize; 313 uint64_t h64; 314 315 if (state->total_len >= 32) { 316 const uint64_t v1 = state->v1; 317 const uint64_t v2 = state->v2; 318 const uint64_t v3 = state->v3; 319 const uint64_t v4 = state->v4; 320 321 h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) + 322 xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18); 323 h64 = xxh64_merge_round(h64, v1); 324 h64 = xxh64_merge_round(h64, v2); 325 h64 = xxh64_merge_round(h64, v3); 326 h64 = xxh64_merge_round(h64, v4); 327 } else { 328 h64 = state->v3 + PRIME64_5; 329 } 330 331 h64 += (uint64_t)state->total_len; 332 333 while (p + 8 <= b_end) { 334 const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p)); 335 336 h64 ^= k1; 337 h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4; 338 p += 8; 339 } 340 341 if (p + 4 <= b_end) { 342 h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1; 343 h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3; 344 p += 4; 345 } 346 347 while (p < b_end) { 348 h64 ^= (*p) * PRIME64_5; 349 h64 = xxh_rotl64(h64, 11) * PRIME64_1; 350 p++; 351 } 352 353 h64 ^= h64 >> 33; 354 h64 *= PRIME64_2; 355 h64 ^= h64 >> 29; 356 h64 *= PRIME64_3; 357 h64 ^= h64 >> 32; 358 359 return h64; 360 } 361 EXPORT_SYMBOL(xxh64_digest); 362 363 MODULE_LICENSE("Dual BSD/GPL"); 364 MODULE_DESCRIPTION("xxHash"); 365