ceph/src/zstd/lib/common/xxhash.h

   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 #ifndef XXH_NAMESPACE
  75 #  define XXH_NAMESPACE ZSTD_  /* Zstandard specific */
  76 #endif
  77
  78
  79 /* ****************************
  80 *  Definitions
  81 ******************************/
  82 #include <stddef.h>   /* size_t */
  83 typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode;
  84
  85
  86 /* ****************************
  87 *  API modifier
  88 ******************************/
  89 /** XXH_PRIVATE_API
  90 *   This is useful if you want to include xxhash functions in `static` mode
  91 *   in order to inline them, and remove their symbol from the public list.
  92 *   Methodology :
  93 *     #define XXH_PRIVATE_API
  94 *     #include "xxhash.h"
  95 *   `xxhash.c` is automatically included.
  96 *   It's not useful to compile and link it as a separate module anymore.
  97 */
  98 #ifdef XXH_PRIVATE_API
  99 #  ifndef XXH_STATIC_LINKING_ONLY
 100 #    define XXH_STATIC_LINKING_ONLY
 101 #  endif
 102 #  if defined(__GNUC__)
 103 #    define XXH_PUBLIC_API static __inline __attribute__((unused))
 104 #  elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 105 #    define XXH_PUBLIC_API static inline
 106 #  elif defined(_MSC_VER)
 107 #    define XXH_PUBLIC_API static __inline
 108 #  else
 109 #    define XXH_PUBLIC_API static   /* this version may generate warnings for unused static functions; disable the relevant warning */
 110 #  endif
 111 #else
 112 #  define XXH_PUBLIC_API   /* do nothing */
 113 #endif /* XXH_PRIVATE_API */
 114
 115 /*!XXH_NAMESPACE, aka Namespace Emulation :
 116
 117 If you want to include _and expose_ xxHash functions from within your own library,
 118 but also want to avoid symbol collisions with another library which also includes xxHash,
 119
 120 you can use XXH_NAMESPACE, to automatically prefix any public symbol from xxhash library
 121 with the value of XXH_NAMESPACE (so avoid to keep it NULL and avoid numeric values).
 122
 123 Note that no change is required within the calling program as long as it includes `xxhash.h` :
 124 regular symbol name will be automatically translated by this header.
 125 */
 126 #ifdef XXH_NAMESPACE
 127 #  define XXH_CAT(A,B) A##B
 128 #  define XXH_NAME2(A,B) XXH_CAT(A,B)
 129 #  define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
 130 #  define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
 131 #  define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber)
 132 #  define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
 133 #  define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
 134 #  define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
 135 #  define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
 136 #  define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
 137 #  define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
 138 #  define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
 139 #  define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
 140 #  define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
 141 #  define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
 142 #  define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState)
 143 #  define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState)
 144 #  define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash)
 145 #  define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash)
 146 #  define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical)
 147 #  define XXH64_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH64_hashFromCanonical)
 148 #endif
 149
 150
 151 /* *************************************
 152 *  Version
 153 ***************************************/
 154 #define XXH_VERSION_MAJOR    0
 155 #define XXH_VERSION_MINOR    6
 156 #define XXH_VERSION_RELEASE  2
 157 #define XXH_VERSION_NUMBER  (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE)
 158 XXH_PUBLIC_API unsigned XXH_versionNumber (void);
 159
 160
 161 /* ****************************
 162 *  Simple Hash Functions
 163 ******************************/
 164 typedef unsigned int       XXH32_hash_t;
 165 typedef unsigned long long XXH64_hash_t;
 166
 167 XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t length, unsigned int seed);
 168 XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t length, unsigned long long seed);
 169
 170 /*!
 171 XXH32() :
 172     Calculate the 32-bits hash of sequence "length" bytes stored at memory address "input".
 173     The memory between input & input+length must be valid (allocated and read-accessible).
 174     "seed" can be used to alter the result predictably.
 175     Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
 176 XXH64() :
 177     Calculate the 64-bits hash of sequence of length "len" stored at memory address "input".
 178     "seed" can be used to alter the result predictably.
 179     This function runs 2x faster on 64-bits systems, but slower on 32-bits systems (see benchmark).
 180 */
 181
 182
 183 /* ****************************
 184 *  Streaming Hash Functions
 185 ******************************/
 186 typedef struct XXH32_state_s XXH32_state_t;   /* incomplete type */
 187 typedef struct XXH64_state_s XXH64_state_t;   /* incomplete type */
 188
 189 /*! State allocation, compatible with dynamic libraries */
 190
 191 XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void);
 192 XXH_PUBLIC_API XXH_errorcode  XXH32_freeState(XXH32_state_t* statePtr);
 193
 194 XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void);
 195 XXH_PUBLIC_API XXH_errorcode  XXH64_freeState(XXH64_state_t* statePtr);
 196
 197
 198 /* hash streaming */
 199
 200 XXH_PUBLIC_API XXH_errorcode XXH32_reset  (XXH32_state_t* statePtr, unsigned int seed);
 201 XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length);
 202 XXH_PUBLIC_API XXH32_hash_t  XXH32_digest (const XXH32_state_t* statePtr);
 203
 204 XXH_PUBLIC_API XXH_errorcode XXH64_reset  (XXH64_state_t* statePtr, unsigned long long seed);
 205 XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length);
 206 XXH_PUBLIC_API XXH64_hash_t  XXH64_digest (const XXH64_state_t* statePtr);
 207
 208 /*
 209 These functions generate the xxHash of an input provided in multiple segments.
 210 Note that, for small input, they are slower than single-call functions, due to state management.
 211 For small input, prefer `XXH32()` and `XXH64()` .
 212
 213 XXH state must first be allocated, using XXH*_createState() .
 214
 215 Start a new hash by initializing state with a seed, using XXH*_reset().
 216
 217 Then, feed the hash state by calling XXH*_update() as many times as necessary.
 218 Obviously, input must be allocated and read accessible.
 219 The function returns an error code, with 0 meaning OK, and any other value meaning there is an error.
 220
 221 Finally, a hash value can be produced anytime, by using XXH*_digest().
 222 This function returns the nn-bits hash as an int or long long.
 223
 224 It's still possible to continue inserting input into the hash state after a digest,
 225 and generate some new hashes later on, by calling again XXH*_digest().
 226
 227 When done, free XXH state space if it was allocated dynamically.
 228 */
 229
 230
 231 /* **************************
 232 *  Utils
 233 ****************************/
 234 #if !(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L))   /* ! C99 */
 235 #  define restrict   /* disable restrict */
 236 #endif
 237
 238 XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* restrict dst_state, const XXH32_state_t* restrict src_state);
 239 XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* restrict dst_state, const XXH64_state_t* restrict src_state);
 240
 241
 242 /* **************************
 243 *  Canonical representation
 244 ****************************/
 245 typedef struct { unsigned char digest[4]; } XXH32_canonical_t;
 246 typedef struct { unsigned char digest[8]; } XXH64_canonical_t;
 247
 248 XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash);
 249 XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash);
 250
 251 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src);
 252 XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src);
 253
 254 /* Default result type for XXH functions are primitive unsigned 32 and 64 bits.
 255 *  The canonical representation uses human-readable write convention, aka big-endian (large digits first).
 256 *  These functions allow transformation of hash result into and from its canonical format.
 257 *  This way, hash values can be written into a file / memory, and remain comparable on different systems and programs.
 258 */
 259
 260
 261 #ifdef XXH_STATIC_LINKING_ONLY
 262
 263 /* ================================================================================================
 264    This section contains definitions which are not guaranteed to remain stable.
 265    They may change in future versions, becoming incompatible with a different version of the library.
 266    They shall only be used with static linking.
 267    Never use these definitions in association with dynamic linking !
 268 =================================================================================================== */
 269
 270 /* These definitions are only meant to allow allocation of XXH state
 271    statically, on stack, or in a struct for example.
 272    Do not use members directly. */
 273
 274    struct XXH32_state_s {
 275        unsigned total_len_32;
 276        unsigned large_len;
 277        unsigned v1;
 278        unsigned v2;
 279        unsigned v3;
 280        unsigned v4;
 281        unsigned mem32[4];   /* buffer defined as U32 for alignment */
 282        unsigned memsize;
 283        unsigned reserved;   /* never read nor write, will be removed in a future version */
 284    };   /* typedef'd to XXH32_state_t */
 285
 286    struct XXH64_state_s {
 287        unsigned long long total_len;
 288        unsigned long long v1;
 289        unsigned long long v2;
 290        unsigned long long v3;
 291        unsigned long long v4;
 292        unsigned long long mem64[4];   /* buffer defined as U64 for alignment */
 293        unsigned memsize;
 294        unsigned reserved[2];          /* never read nor write, will be removed in a future version */
 295    };   /* typedef'd to XXH64_state_t */
 296
 297
 298 #  ifdef XXH_PRIVATE_API
 299 #    include "xxhash.c"   /* include xxhash functions as `static`, for inlining */
 300 #  endif
 301
 302 #endif /* XXH_STATIC_LINKING_ONLY */
 303
 304
 305 #if defined (__cplusplus)
 306 }
 307 #endif
 308
 309 #endif /* XXHASH_H_5627135585666179 */