xxhash.h

/*
 * xxHash - Extremely Fast Hash algorithm
 * Header File
 * Copyright (c) 2012-2020, Yann Collet, Facebook, Inc.
 *
 * You can contact the author at :
 * - xxHash source repository : https://github.com/Cyan4973/xxHash
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
*/
 
/* Notice extracted from xxHash homepage :
 
xxHash is an extremely fast Hash algorithm, running at RAM speed limits.
It also successfully passes all tests from the SMHasher suite.
 
Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz)
 
Name            Speed       Q.Score   Author
xxHash          5.4 GB/s     10
CrapWow         3.2 GB/s      2       Andrew
MumurHash 3a    2.7 GB/s     10       Austin Appleby
SpookyHash      2.0 GB/s     10       Bob Jenkins
SBox            1.4 GB/s      9       Bret Mulvey
Lookup3         1.2 GB/s      9       Bob Jenkins
SuperFastHash   1.2 GB/s      1       Paul Hsieh
CityHash64      1.05 GB/s    10       Pike & Alakuijala
FNV             0.55 GB/s     5       Fowler, Noll, Vo
CRC32           0.43 GB/s     9
MD5-32          0.33 GB/s    10       Ronald L. Rivest
SHA1-32         0.28 GB/s    10
 
Q.Score is a measure of quality of the hash function.
It depends on successfully passing SMHasher test set.
10 is a perfect score.
 
A 64-bits version, named XXH64, is available since r35.
It offers much better speed, but for 64-bits applications only.
Name     Speed on 64 bits    Speed on 32 bits
XXH64       13.8 GB/s            1.9 GB/s
XXH32        6.8 GB/s            6.0 GB/s
*/
 
#if defined (__cplusplus)
extern "C" {
#endif
 
#ifndef XXHASH_H_5627135585666179
#define XXHASH_H_5627135585666179 1
 
 
/* ****************************
*  Definitions
******************************/
#include <stddef.h>   /* size_t */
#include <stdint.h>   /* uintxx_t */
typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode;
 
 
/* ****************************
*  API modifier
******************************/
#ifdef XXH_PRIVATE_API
#  ifndef XXH_STATIC_LINKING_ONLY
#    define XXH_STATIC_LINKING_ONLY
#  endif
#  if defined(__GNUC__)
#    define XXH_PUBLIC_API static __inline __attribute__((unused))
#  elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#    define XXH_PUBLIC_API static inline
#  elif defined(_MSC_VER)
#    define XXH_PUBLIC_API static __inline
#  else
#    define XXH_PUBLIC_API static   /* this version may generate warnings for unused static functions; disable the relevant warning */
#  endif
#else
#  define XXH_PUBLIC_API   /* do nothing */
#endif /* XXH_PRIVATE_API */
 
#ifdef XXH_NAMESPACE
#  define XXH_CAT(A,B) A##B
#  define XXH_NAME2(A,B) XXH_CAT(A,B)
#  define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
#  define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
#  define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber)
#  define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
#  define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
#  define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
#  define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
#  define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
#  define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
#  define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
#  define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
#  define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
#  define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
#  define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState)
#  define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState)
#  define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash)
#  define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash)
#  define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical)
#  define XXH64_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH64_hashFromCanonical)
#endif
 
 
/* *************************************
*  Version
***************************************/
#define XXH_VERSION_MAJOR    0
#define XXH_VERSION_MINOR    6
#define XXH_VERSION_RELEASE  2
#define XXH_VERSION_NUMBER  (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE)
XXH_PUBLIC_API unsigned XXH_versionNumber (void);
 
 
/* ****************************
*  Simple Hash Functions
******************************/
typedef unsigned int       XXH32_hash_t;
typedef unsigned long long XXH64_hash_t;
 
XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t length, unsigned int seed);
XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t length, unsigned long long seed);
 
/* ****************************
*  Streaming Hash Functions
******************************/
typedef struct XXH32_state_s XXH32_state_t;   /* incomplete type */
typedef struct XXH64_state_s XXH64_state_t;   /* incomplete type */
 
XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void);
XXH_PUBLIC_API XXH_errorcode  XXH32_freeState(XXH32_state_t* statePtr);
 
XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void);
XXH_PUBLIC_API XXH_errorcode  XXH64_freeState(XXH64_state_t* statePtr);
 
 
/* hash streaming */
 
XXH_PUBLIC_API XXH_errorcode XXH32_reset  (XXH32_state_t* statePtr, unsigned int seed);
XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length);
XXH_PUBLIC_API XXH32_hash_t  XXH32_digest (const XXH32_state_t* statePtr);
 
XXH_PUBLIC_API XXH_errorcode XXH64_reset  (XXH64_state_t* statePtr, unsigned long long seed);
XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length);
XXH_PUBLIC_API XXH64_hash_t  XXH64_digest (const XXH64_state_t* statePtr);
 
/*
These functions generate the xxHash of an input provided in multiple segments.
Note that, for small input, they are slower than single-call functions, due to state management.
For small input, prefer `XXH32()` and `XXH64()` .
 
XXH state must first be allocated, using XXH*_createState() .
 
Start a new hash by initializing state with a seed, using XXH*_reset().
 
Then, feed the hash state by calling XXH*_update() as many times as necessary.
Obviously, input must be allocated and read accessible.
The function returns an error code, with 0 meaning OK, and any other value meaning there is an error.
 
Finally, a hash value can be produced anytime, by using XXH*_digest().
This function returns the nn-bits hash as an int or long long.
 
It's still possible to continue inserting input into the hash state after a digest,
and generate some new hashes later on, by calling again XXH*_digest().
 
When done, free XXH state space if it was allocated dynamically.
*/
 
 
/* **************************
*  Utils
****************************/
#if !(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L))   /* ! C99 */
#  define restrict   /* disable restrict */
#endif
 
XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* restrict dst_state, const XXH32_state_t* restrict src_state);
XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* restrict dst_state, const XXH64_state_t* restrict src_state);
 
 
/* **************************
*  Canonical representation
****************************/
/* Default result type for XXH functions are primitive unsigned 32 and 64 bits.
*  The canonical representation uses human-readable write convention, aka big-endian (large digits first).
*  These functions allow transformation of hash result into and from its canonical format.
*  This way, hash values can be written into a file / memory, and remain comparable on different systems and programs.
*/
typedef struct { unsigned char digest[4]; } XXH32_canonical_t;
typedef struct { unsigned char digest[8]; } XXH64_canonical_t;
 
XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash);
XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash);
 
XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src);
XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src);
 
#endif /* XXHASH_H_5627135585666179 */
 
 
 
/* ================================================================================================
   This section contains definitions which are not guaranteed to remain stable.
   They may change in future versions, becoming incompatible with a different version of the library.
   They shall only be used with static linking.
   Never use these definitions in association with dynamic linking !
=================================================================================================== */
#if defined(XXH_STATIC_LINKING_ONLY) && !defined(XXH_STATIC_H_3543687687345)
#define XXH_STATIC_H_3543687687345
 
/* These definitions are only meant to allow allocation of XXH state
   statically, on stack, or in a struct for example.
   Do not use members directly. */
 
   struct XXH32_state_s {
       uint32_t total_len_32;
       uint32_t large_len;
       uint32_t v1;
       uint32_t v2;
       uint32_t v3;
       uint32_t v4;
       uint32_t mem32[4];   /* buffer defined as U32 for alignment */
       uint32_t memsize;
       uint32_t reserved;   /* never read nor write, will be removed in a future version */
   };   /* typedef'd to XXH32_state_t */
 
   struct XXH64_state_s {
       uint64_t total_len;
       uint64_t v1;
       uint64_t v2;
       uint64_t v3;
       uint64_t v4;
       uint64_t mem64[4];   /* buffer defined as U64 for alignment */
       unsigned memsize;
       unsigned reserved[2];          /* never read nor write, will be removed in a future version */
   };   /* typedef'd to XXH64_state_t */
 
 
#  ifdef XXH_PRIVATE_API
#    include "xxhash.c"   /* include xxhash functions as `static`, for inlining */
#  endif
 
#endif /* XXH_STATIC_LINKING_ONLY && XXH_STATIC_H_3543687687345 */
 
 
#if defined (__cplusplus)
}
#endif