module/zstd/lib/common/xxhash.h

   1 /*
   2  * xxHash - Extremely Fast Hash algorithm
   3  * Header File
   4  * Copyright (c) 2012-2020, Yann Collet, Facebook, Inc.
   5  *
   6  * You can contact the author at :
   7  * - xxHash source repository : https://github.com/Cyan4973/xxHash
   8  *
   9  * This source code is licensed under both the BSD-style license (found in the
  10  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  11  * in the COPYING file in the root directory of this source tree).
  12  * You may select, at your option, one of the above-listed licenses.
  13 */
  14
  15 /* Notice extracted from xxHash homepage :
  16
  17 xxHash is an extremely fast Hash algorithm, running at RAM speed limits.
  18 It also successfully passes all tests from the SMHasher suite.
  19
  20 Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz)
  21
  22 Name            Speed       Q.Score   Author
  23 xxHash          5.4 GB/s     10
  24 CrapWow         3.2 GB/s      2       Andrew
  25 MumurHash 3a    2.7 GB/s     10       Austin Appleby
  26 SpookyHash      2.0 GB/s     10       Bob Jenkins
  27 SBox            1.4 GB/s      9       Bret Mulvey
  28 Lookup3         1.2 GB/s      9       Bob Jenkins
  29 SuperFastHash   1.2 GB/s      1       Paul Hsieh
  30 CityHash64      1.05 GB/s    10       Pike & Alakuijala
  31 FNV             0.55 GB/s     5       Fowler, Noll, Vo
  32 CRC32           0.43 GB/s     9
  33 MD5-32          0.33 GB/s    10       Ronald L. Rivest
  34 SHA1-32         0.28 GB/s    10
  35
  36 Q.Score is a measure of quality of the hash function.
  37 It depends on successfully passing SMHasher test set.
  38 10 is a perfect score.
  39
  40 A 64-bits version, named XXH64, is available since r35.
  41 It offers much better speed, but for 64-bits applications only.
  42 Name     Speed on 64 bits    Speed on 32 bits
  43 XXH64       13.8 GB/s            1.9 GB/s
  44 XXH32        6.8 GB/s            6.0 GB/s
  45 */
  46
  47 #if defined (__cplusplus)
  48 extern "C" {
  49 #endif
  50
  51 #ifndef XXHASH_H_5627135585666179
  52 #define XXHASH_H_5627135585666179 1
  53
  54
  55 /* ****************************
  56 *  Definitions
  57 ******************************/
  58 #include <stddef.h>   /* size_t */
  59 typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode;
  60
  61
  62 /* ****************************
  63 *  API modifier
  64 ******************************/
  65 /** XXH_PRIVATE_API
  66 *   This is useful if you want to include xxhash functions in `static` mode
  67 *   in order to inline them, and remove their symbol from the public list.
  68 *   Methodology :
  69 *     #define XXH_PRIVATE_API
  70 *     #include "xxhash.h"
  71 *   `xxhash.c` is automatically included.
  72 *   It's not useful to compile and link it as a separate module anymore.
  73 */
  74 #ifdef XXH_PRIVATE_API
  75 #  ifndef XXH_STATIC_LINKING_ONLY
  76 #    define XXH_STATIC_LINKING_ONLY
  77 #  endif
  78 #  if defined(__GNUC__)
  79 #    define XXH_PUBLIC_API static __inline __attribute__((unused))
  80 #  elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
  81 #    define XXH_PUBLIC_API static inline
  82 #  elif defined(_MSC_VER)
  83 #    define XXH_PUBLIC_API static __inline
  84 #  else
  85 #    define XXH_PUBLIC_API static   /* this version may generate warnings for unused static functions; disable the relevant warning */
  86 #  endif
  87 #else
  88 #  define XXH_PUBLIC_API   /* do nothing */
  89 #endif /* XXH_PRIVATE_API */
  90
  91 /*!XXH_NAMESPACE, aka Namespace Emulation :
  92
  93 If you want to include _and expose_ xxHash functions from within your own library,
  94 but also want to avoid symbol collisions with another library which also includes xxHash,
  95
  96 you can use XXH_NAMESPACE, to automatically prefix any public symbol from xxhash library
  97 with the value of XXH_NAMESPACE (so avoid to keep it NULL and avoid numeric values).
  98
  99 Note that no change is required within the calling program as long as it includes `xxhash.h` :
 100 regular symbol name will be automatically translated by this header.
 101 */
 102 #ifdef XXH_NAMESPACE
 103 #  define XXH_CAT(A,B) A##B
 104 #  define XXH_NAME2(A,B) XXH_CAT(A,B)
 105 #  define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
 106 #  define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
 107 #  define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber)
 108 #  define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
 109 #  define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
 110 #  define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
 111 #  define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
 112 #  define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
 113 #  define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
 114 #  define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
 115 #  define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
 116 #  define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
 117 #  define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
 118 #  define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState)
 119 #  define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState)
 120 #  define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash)
 121 #  define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash)
 122 #  define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical)
 123 #  define XXH64_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH64_hashFromCanonical)
 124 #endif
 125
 126
 127 /* *************************************
 128 *  Version
 129 ***************************************/
 130 #define XXH_VERSION_MAJOR    0
 131 #define XXH_VERSION_MINOR    6
 132 #define XXH_VERSION_RELEASE  2
 133 #define XXH_VERSION_NUMBER  (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE)
 134 XXH_PUBLIC_API unsigned XXH_versionNumber (void);
 135
 136
 137 /* ****************************
 138 *  Simple Hash Functions
 139 ******************************/
 140 typedef unsigned int       XXH32_hash_t;
 141 typedef unsigned long long XXH64_hash_t;
 142
 143 XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t length, unsigned int seed);
 144 XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t length, unsigned long long seed);
 145
 146 /*!
 147 XXH32() :
 148     Calculate the 32-bits hash of sequence "length" bytes stored at memory address "input".
 149     The memory between input & input+length must be valid (allocated and read-accessible).
 150     "seed" can be used to alter the result predictably.
 151     Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
 152 XXH64() :
 153     Calculate the 64-bits hash of sequence of length "len" stored at memory address "input".
 154     "seed" can be used to alter the result predictably.
 155     This function runs 2x faster on 64-bits systems, but slower on 32-bits systems (see benchmark).
 156 */
 157
 158
 159 /* ****************************
 160 *  Streaming Hash Functions
 161 ******************************/
 162 typedef struct XXH32_state_s XXH32_state_t;   /* incomplete type */
 163 typedef struct XXH64_state_s XXH64_state_t;   /* incomplete type */
 164
 165 /*! State allocation, compatible with dynamic libraries */
 166
 167 XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void);
 168 XXH_PUBLIC_API XXH_errorcode  XXH32_freeState(XXH32_state_t* statePtr);
 169
 170 XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void);
 171 XXH_PUBLIC_API XXH_errorcode  XXH64_freeState(XXH64_state_t* statePtr);
 172
 173
 174 /* hash streaming */
 175
 176 XXH_PUBLIC_API XXH_errorcode XXH32_reset  (XXH32_state_t* statePtr, unsigned int seed);
 177 XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length);
 178 XXH_PUBLIC_API XXH32_hash_t  XXH32_digest (const XXH32_state_t* statePtr);
 179
 180 XXH_PUBLIC_API XXH_errorcode XXH64_reset  (XXH64_state_t* statePtr, unsigned long long seed);
 181 XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length);
 182 XXH_PUBLIC_API XXH64_hash_t  XXH64_digest (const XXH64_state_t* statePtr);
 183
 184 /*
 185 These functions generate the xxHash of an input provided in multiple segments.
 186 Note that, for small input, they are slower than single-call functions, due to state management.
 187 For small input, prefer `XXH32()` and `XXH64()` .
 188
 189 XXH state must first be allocated, using XXH*_createState() .
 190
 191 Start a new hash by initializing state with a seed, using XXH*_reset().
 192
 193 Then, feed the hash state by calling XXH*_update() as many times as necessary.
 194 Obviously, input must be allocated and read accessible.
 195 The function returns an error code, with 0 meaning OK, and any other value meaning there is an error.
 196
 197 Finally, a hash value can be produced anytime, by using XXH*_digest().
 198 This function returns the nn-bits hash as an int or long long.
 199
 200 It's still possible to continue inserting input into the hash state after a digest,
 201 and generate some new hashes later on, by calling again XXH*_digest().
 202
 203 When done, free XXH state space if it was allocated dynamically.
 204 */
 205
 206
 207 /* **************************
 208 *  Utils
 209 ****************************/
 210 #if !(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L))   /* ! C99 */
 211 #  define restrict   /* disable restrict */
 212 #endif
 213
 214 XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* restrict dst_state, const XXH32_state_t* restrict src_state);
 215 XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* restrict dst_state, const XXH64_state_t* restrict src_state);
 216
 217
 218 /* **************************
 219 *  Canonical representation
 220 ****************************/
 221 /* Default result type for XXH functions are primitive unsigned 32 and 64 bits.
 222 *  The canonical representation uses human-readable write convention, aka big-endian (large digits first).
 223 *  These functions allow transformation of hash result into and from its canonical format.
 224 *  This way, hash values can be written into a file / memory, and remain comparable on different systems and programs.
 225 */
 226 typedef struct { unsigned char digest[4]; } XXH32_canonical_t;
 227 typedef struct { unsigned char digest[8]; } XXH64_canonical_t;
 228
 229 XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash);
 230 XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash);
 231
 232 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src);
 233 XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src);
 234
 235 #endif /* XXHASH_H_5627135585666179 */
 236
 237
 238
 239 /* ================================================================================================
 240    This section contains definitions which are not guaranteed to remain stable.
 241    They may change in future versions, becoming incompatible with a different version of the library.
 242    They shall only be used with static linking.
 243    Never use these definitions in association with dynamic linking !
 244 =================================================================================================== */
 245 #if defined(XXH_STATIC_LINKING_ONLY) && !defined(XXH_STATIC_H_3543687687345)
 246 #define XXH_STATIC_H_3543687687345
 247
 248 /* These definitions are only meant to allow allocation of XXH state
 249    statically, on stack, or in a struct for example.
 250    Do not use members directly. */
 251
 252    struct XXH32_state_s {
 253        unsigned total_len_32;
 254        unsigned large_len;
 255        unsigned v1;
 256        unsigned v2;
 257        unsigned v3;
 258        unsigned v4;
 259        unsigned mem32[4];   /* buffer defined as U32 for alignment */
 260        unsigned memsize;
 261        unsigned reserved;   /* never read nor write, will be removed in a future version */
 262    };   /* typedef'd to XXH32_state_t */
 263
 264    struct XXH64_state_s {
 265        unsigned long long total_len;
 266        unsigned long long v1;
 267        unsigned long long v2;
 268        unsigned long long v3;
 269        unsigned long long v4;
 270        unsigned long long mem64[4];   /* buffer defined as U64 for alignment */
 271        unsigned memsize;
 272        unsigned reserved[2];          /* never read nor write, will be removed in a future version */
 273    };   /* typedef'd to XXH64_state_t */
 274
 275
 276 #  ifdef XXH_PRIVATE_API
 277 #    include "xxhash.c"   /* include xxhash functions as `static`, for inlining */
 278 #  endif
 279
 280 #endif /* XXH_STATIC_LINKING_ONLY && XXH_STATIC_H_3543687687345 */
 281
 282
 283 #if defined (__cplusplus)
 284 }
 285 #endif