xxhash.h (12577B)
1 /* 2 xxHash - Extremely Fast Hash algorithm 3 Header File 4 Copyright (C) 2012-2016, Yann Collet. 5 6 BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) 7 8 Redistribution and use in source and binary forms, with or without 9 modification, are permitted provided that the following conditions are 10 met: 11 12 * Redistributions of source code must retain the above copyright 13 notice, this list of conditions and the following disclaimer. 14 * Redistributions in binary form must reproduce the above 15 copyright notice, this list of conditions and the following disclaimer 16 in the documentation and/or other materials provided with the 17 distribution. 18 19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 You can contact the author at : 32 - xxHash source repository : https://github.com/Cyan4973/xxHash 33 */ 34 35 /* Notice extracted from xxHash homepage : 36 37 xxHash is an extremely fast Hash algorithm, running at RAM speed limits. 38 It also successfully passes all tests from the SMHasher suite. 39 40 Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz) 41 42 Name Speed Q.Score Author 43 xxHash 5.4 GB/s 10 44 CrapWow 3.2 GB/s 2 Andrew 45 MumurHash 3a 2.7 GB/s 10 Austin Appleby 46 SpookyHash 2.0 GB/s 10 Bob Jenkins 47 SBox 1.4 GB/s 9 Bret Mulvey 48 Lookup3 1.2 GB/s 9 Bob Jenkins 49 SuperFastHash 1.2 GB/s 1 Paul Hsieh 50 CityHash64 1.05 GB/s 10 Pike & Alakuijala 51 FNV 0.55 GB/s 5 Fowler, Noll, Vo 52 CRC32 0.43 GB/s 9 53 MD5-32 0.33 GB/s 10 Ronald L. Rivest 54 SHA1-32 0.28 GB/s 10 55 56 Q.Score is a measure of quality of the hash function. 57 It depends on successfully passing SMHasher test set. 58 10 is a perfect score. 59 60 A 64-bits version, named XXH64, is available since r35. 61 It offers much better speed, but for 64-bits applications only. 62 Name Speed on 64 bits Speed on 32 bits 63 XXH64 13.8 GB/s 1.9 GB/s 64 XXH32 6.8 GB/s 6.0 GB/s 65 */ 66 67 #ifndef XXHASH_H_5627135585666179 68 #define XXHASH_H_5627135585666179 1 69 70 #if defined (__cplusplus) 71 extern "C" { 72 #endif 73 74 75 /* **************************** 76 * Definitions 77 ******************************/ 78 #include <stddef.h> /* size_t */ 79 typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode; 80 81 82 /* **************************** 83 * API modifier 84 ******************************/ 85 /** XXH_PRIVATE_API 86 * This is useful to include xxhash functions in `static` mode 87 * in order to inline them, and remove their symbol from the public list. 88 * Methodology : 89 * #define XXH_PRIVATE_API 90 * #include "xxhash.h" 91 * `xxhash.c` is automatically included. 92 * It's not useful to compile and link it as a separate module. 93 */ 94 #ifdef XXH_PRIVATE_API 95 # ifndef XXH_STATIC_LINKING_ONLY 96 # define XXH_STATIC_LINKING_ONLY 97 # endif 98 # if defined(__GNUC__) 99 # define XXH_PUBLIC_API static __inline __attribute__((unused)) 100 # elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) 101 # define XXH_PUBLIC_API static inline 102 # elif defined(_MSC_VER) 103 # define XXH_PUBLIC_API static __inline 104 # else 105 # define XXH_PUBLIC_API static /* this version may generate warnings for unused static functions; disable the relevant warning */ 106 # endif 107 #else 108 # define XXH_PUBLIC_API /* do nothing */ 109 #endif /* XXH_PRIVATE_API */ 110 111 /*!XXH_NAMESPACE, aka Namespace Emulation : 112 113 If you want to include _and expose_ xxHash functions from within your own library, 114 but also want to avoid symbol collisions with other libraries which may also include xxHash, 115 116 you can use XXH_NAMESPACE, to automatically prefix any public symbol from xxhash library 117 with the value of XXH_NAMESPACE (therefore, avoid NULL and numeric values). 118 119 Note that no change is required within the calling program as long as it includes `xxhash.h` : 120 regular symbol name will be automatically translated by this header. 121 */ 122 #ifdef XXH_NAMESPACE 123 # define XXH_CAT(A,B) A##B 124 # define XXH_NAME2(A,B) XXH_CAT(A,B) 125 # define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber) 126 # define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32) 127 # define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState) 128 # define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState) 129 # define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset) 130 # define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update) 131 # define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest) 132 # define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState) 133 # define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash) 134 # define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical) 135 # define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64) 136 # define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState) 137 # define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState) 138 # define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset) 139 # define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update) 140 # define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest) 141 # define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState) 142 # define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash) 143 # define XXH64_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH64_hashFromCanonical) 144 #endif 145 146 147 /* ************************************* 148 * Version 149 ***************************************/ 150 #define XXH_VERSION_MAJOR 0 151 #define XXH_VERSION_MINOR 6 152 #define XXH_VERSION_RELEASE 2 153 #define XXH_VERSION_NUMBER (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE) 154 XXH_PUBLIC_API unsigned XXH_versionNumber (void); 155 156 157 /*-********************************************************************** 158 * 32-bits hash 159 ************************************************************************/ 160 typedef unsigned int XXH32_hash_t; 161 162 /*! XXH32() : 163 Calculate the 32-bits hash of sequence "length" bytes stored at memory address "input". 164 The memory between input & input+length must be valid (allocated and read-accessible). 165 "seed" can be used to alter the result predictably. 166 Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s */ 167 XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t length, unsigned int seed); 168 169 /*====== Streaming ======*/ 170 typedef struct XXH32_state_s XXH32_state_t; /* incomplete type */ 171 XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void); 172 XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr); 173 XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dst_state, const XXH32_state_t* src_state); 174 175 XXH_PUBLIC_API XXH_errorcode XXH32_reset (XXH32_state_t* statePtr, unsigned int seed); 176 XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length); 177 XXH_PUBLIC_API XXH32_hash_t XXH32_digest (const XXH32_state_t* statePtr); 178 179 /* 180 These functions generate the xxHash of an input provided in multiple segments. 181 Note that, for small input, they are slower than single-call functions, due to state management. 182 For small input, prefer `XXH32()` and `XXH64()` . 183 184 XXH state must first be allocated, using XXH*_createState() . 185 186 Start a new hash by initializing state with a seed, using XXH*_reset(). 187 188 Then, feed the hash state by calling XXH*_update() as many times as necessary. 189 Obviously, input must be allocated and read accessible. 190 The function returns an error code, with 0 meaning OK, and any other value meaning there is an error. 191 192 Finally, a hash value can be produced anytime, by using XXH*_digest(). 193 This function returns the nn-bits hash as an int or long long. 194 195 It's still possible to continue inserting input into the hash state after a digest, 196 and generate some new hashes later on, by calling again XXH*_digest(). 197 198 When done, free XXH state space if it was allocated dynamically. 199 */ 200 201 /*====== Canonical representation ======*/ 202 203 typedef struct { unsigned char digest[4]; } XXH32_canonical_t; 204 XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash); 205 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src); 206 207 /* Default result type for XXH functions are primitive unsigned 32 and 64 bits. 208 * The canonical representation uses human-readable write convention, aka big-endian (large digits first). 209 * These functions allow transformation of hash result into and from its canonical format. 210 * This way, hash values can be written into a file / memory, and remain comparable on different systems and programs. 211 */ 212 213 214 #ifndef XXH_NO_LONG_LONG 215 /*-********************************************************************** 216 * 64-bits hash 217 ************************************************************************/ 218 typedef unsigned long long XXH64_hash_t; 219 220 /*! XXH64() : 221 Calculate the 64-bits hash of sequence of length "len" stored at memory address "input". 222 "seed" can be used to alter the result predictably. 223 This function runs faster on 64-bits systems, but slower on 32-bits systems (see benchmark). 224 */ 225 XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t length, unsigned long long seed); 226 227 /*====== Streaming ======*/ 228 typedef struct XXH64_state_s XXH64_state_t; /* incomplete type */ 229 XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void); 230 XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr); 231 XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dst_state, const XXH64_state_t* src_state); 232 233 XXH_PUBLIC_API XXH_errorcode XXH64_reset (XXH64_state_t* statePtr, unsigned long long seed); 234 XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length); 235 XXH_PUBLIC_API XXH64_hash_t XXH64_digest (const XXH64_state_t* statePtr); 236 237 /*====== Canonical representation ======*/ 238 typedef struct { unsigned char digest[8]; } XXH64_canonical_t; 239 XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash); 240 XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src); 241 #endif /* XXH_NO_LONG_LONG */ 242 243 244 #ifdef XXH_STATIC_LINKING_ONLY 245 246 /* ================================================================================================ 247 This section contains definitions which are not guaranteed to remain stable. 248 They may change in future versions, becoming incompatible with a different version of the library. 249 They shall only be used with static linking. 250 Never use these definitions in association with dynamic linking ! 251 =================================================================================================== */ 252 253 /* These definitions are only meant to make possible 254 static allocation of XXH state, on stack or in a struct for example. 255 Never use members directly. */ 256 257 struct XXH32_state_s { 258 unsigned total_len_32; 259 unsigned large_len; 260 unsigned v1; 261 unsigned v2; 262 unsigned v3; 263 unsigned v4; 264 unsigned mem32[4]; /* buffer defined as U32 for alignment */ 265 unsigned memsize; 266 unsigned reserved; /* never read nor write, will be removed in a future version */ 267 }; /* typedef'd to XXH32_state_t */ 268 269 #ifndef XXH_NO_LONG_LONG /* remove 64-bits support */ 270 struct XXH64_state_s { 271 unsigned long long total_len; 272 unsigned long long v1; 273 unsigned long long v2; 274 unsigned long long v3; 275 unsigned long long v4; 276 unsigned long long mem64[4]; /* buffer defined as U64 for alignment */ 277 unsigned memsize; 278 unsigned reserved[2]; /* never read nor write, will be removed in a future version */ 279 }; /* typedef'd to XXH64_state_t */ 280 #endif 281 282 #ifdef XXH_PRIVATE_API 283 # include "xxhash.c" /* include xxhash function bodies as `static`, for inlining */ 284 #endif 285 286 #endif /* XXH_STATIC_LINKING_ONLY */ 287 288 289 #if defined (__cplusplus) 290 } 291 #endif 292 293 #endif /* XXHASH_H_5627135585666179 */