drivers/filesystems/btrfs/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 #if defined (__cplusplus)
  68 extern "C" {
  69 #endif
  70
  71 #ifndef XXHASH_H_5627135585666179
  72 #define XXHASH_H_5627135585666179 1
  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 if you want 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 anymore.
  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 another library which also includes xxHash,
 115
 116 you can use XXH_NAMESPACE, to automatically prefix any public symbol from xxhash library
 117 with the value of XXH_NAMESPACE (so avoid to keep it NULL and avoid 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 XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
 126 #  define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
 127 #  define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber)
 128 #  define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
 129 #  define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
 130 #  define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
 131 #  define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
 132 #  define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
 133 #  define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
 134 #  define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
 135 #  define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
 136 #  define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
 137 #  define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
 138 #  define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState)
 139 #  define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState)
 140 #  define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash)
 141 #  define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash)
 142 #  define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical)
 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 *  Simple Hash Functions
 159 ******************************/
 160 typedef unsigned int       XXH32_hash_t;
 161 typedef unsigned long long XXH64_hash_t;
 162
 163 XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t length, unsigned int seed);
 164 XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t length, unsigned long long seed);
 165
 166 /*!
 167 XXH32() :
 168     Calculate the 32-bits hash of sequence "length" bytes stored at memory address "input".
 169     The memory between input & input+length must be valid (allocated and read-accessible).
 170     "seed" can be used to alter the result predictably.
 171     Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
 172 XXH64() :
 173     Calculate the 64-bits hash of sequence of length "len" stored at memory address "input".
 174     "seed" can be used to alter the result predictably.
 175     This function runs 2x faster on 64-bits systems, but slower on 32-bits systems (see benchmark).
 176 */
 177
 178
 179 /* ****************************
 180 *  Streaming Hash Functions
 181 ******************************/
 182 typedef struct XXH32_state_s XXH32_state_t;   /* incomplete type */
 183 typedef struct XXH64_state_s XXH64_state_t;   /* incomplete type */
 184
 185 /*! State allocation, compatible with dynamic libraries */
 186
 187 XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void);
 188 XXH_PUBLIC_API XXH_errorcode  XXH32_freeState(XXH32_state_t* statePtr);
 189
 190 XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void);
 191 XXH_PUBLIC_API XXH_errorcode  XXH64_freeState(XXH64_state_t* statePtr);
 192
 193
 194 /* hash streaming */
 195
 196 XXH_PUBLIC_API XXH_errorcode XXH32_reset  (XXH32_state_t* statePtr, unsigned int seed);
 197 XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length);
 198 XXH_PUBLIC_API XXH32_hash_t  XXH32_digest (const XXH32_state_t* statePtr);
 199
 200 XXH_PUBLIC_API XXH_errorcode XXH64_reset  (XXH64_state_t* statePtr, unsigned long long seed);
 201 XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length);
 202 XXH_PUBLIC_API XXH64_hash_t  XXH64_digest (const XXH64_state_t* statePtr);
 203
 204 /*
 205 These functions generate the xxHash of an input provided in multiple segments.
 206 Note that, for small input, they are slower than single-call functions, due to state management.
 207 For small input, prefer `XXH32()` and `XXH64()` .
 208
 209 XXH state must first be allocated, using XXH*_createState() .
 210
 211 Start a new hash by initializing state with a seed, using XXH*_reset().
 212
 213 Then, feed the hash state by calling XXH*_update() as many times as necessary.
 214 Obviously, input must be allocated and read accessible.
 215 The function returns an error code, with 0 meaning OK, and any other value meaning there is an error.
 216
 217 Finally, a hash value can be produced anytime, by using XXH*_digest().
 218 This function returns the nn-bits hash as an int or long long.
 219
 220 It's still possible to continue inserting input into the hash state after a digest,
 221 and generate some new hashes later on, by calling again XXH*_digest().
 222
 223 When done, free XXH state space if it was allocated dynamically.
 224 */
 225
 226
 227 /* **************************
 228 *  Utils
 229 ****************************/
 230 #if !(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L))   /* ! C99 */
 231 #  define restrict   /* disable restrict */
 232 #endif
 233
 234 XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* restrict dst_state, const XXH32_state_t* restrict src_state);
 235 XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* restrict dst_state, const XXH64_state_t* restrict src_state);
 236
 237
 238 /* **************************
 239 *  Canonical representation
 240 ****************************/
 241 /* Default result type for XXH functions are primitive unsigned 32 and 64 bits.
 242 *  The canonical representation uses human-readable write convention, aka big-endian (large digits first).
 243 *  These functions allow transformation of hash result into and from its canonical format.
 244 *  This way, hash values can be written into a file / memory, and remain comparable on different systems and programs.
 245 */
 246 typedef struct { unsigned char digest[4]; } XXH32_canonical_t;
 247 typedef struct { unsigned char digest[8]; } XXH64_canonical_t;
 248
 249 XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash);
 250 XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash);
 251
 252 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src);
 253 XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src);
 254
 255 #endif /* XXHASH_H_5627135585666179 */
 256
 257
 258
 259 /* ================================================================================================
 260    This section contains definitions which are not guaranteed to remain stable.
 261    They may change in future versions, becoming incompatible with a different version of the library.
 262    They shall only be used with static linking.
 263    Never use these definitions in association with dynamic linking !
 264 =================================================================================================== */
 265 #if defined(XXH_STATIC_LINKING_ONLY) && !defined(XXH_STATIC_H_3543687687345)
 266 #define XXH_STATIC_H_3543687687345
 267
 268 /* These definitions are only meant to allow allocation of XXH state
 269    statically, on stack, or in a struct for example.
 270    Do not use members directly. */
 271
 272    struct XXH32_state_s {
 273        unsigned total_len_32;
 274        unsigned large_len;
 275        unsigned v1;
 276        unsigned v2;
 277        unsigned v3;
 278        unsigned v4;
 279        unsigned mem32[4];   /* buffer defined as U32 for alignment */
 280        unsigned memsize;
 281        unsigned reserved;   /* never read nor write, will be removed in a future version */
 282    };   /* typedef'd to XXH32_state_t */
 283
 284    struct XXH64_state_s {
 285        unsigned long long total_len;
 286        unsigned long long v1;
 287        unsigned long long v2;
 288        unsigned long long v3;
 289        unsigned long long v4;
 290        unsigned long long mem64[4];   /* buffer defined as U64 for alignment */
 291        unsigned memsize;
 292        unsigned reserved[2];          /* never read nor write, will be removed in a future version */
 293    };   /* typedef'd to XXH64_state_t */
 294
 295
 296 #  ifdef XXH_PRIVATE_API
 297 #    include "xxhash.c"   /* include xxhash functions as `static`, for inlining */
 298 #  endif
 299
 300 #endif /* XXH_STATIC_LINKING_ONLY && XXH_STATIC_H_3543687687345 */
 301
 302
 303 #if defined (__cplusplus)
 304 }
 305 #endif