@ -1,8 +1,12 @@
// Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
// Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
/*
/*
xxHash - Fast Hash algorithm xxHash - Extremely Fast Hash algorithm
Header File Header File
Copyright ( C ) 2012 - 2014 , Yann Collet . Copyright ( C ) 2012 - 2016 , Yann Collet .
BSD 2 - Clause License ( http : //www.opensource.org/licenses/bsd-license.php)
BSD 2 - Clause License ( http : //www.opensource.org/licenses/bsd-license.php)
Redistribution and use in source and binary forms , with or without Redistribution and use in source and binary forms , with or without
@ -29,7 +33,7 @@
OF THIS SOFTWARE , EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE . OF THIS SOFTWARE , EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE .
You can contact the author at : You can contact the author at :
- xxHash source repository : http : //code.google.com/p/xxhash/
- xxHash source repository : https : //github.com/Cyan4973/xxHash
*/ */
/* Notice extracted from xxHash homepage :
/* Notice extracted from xxHash homepage :
@ -49,193 +53,546 @@ Lookup3 1.2 GB/s 9 Bob Jenkins
SuperFastHash 1.2 GB / s 1 Paul Hsieh SuperFastHash 1.2 GB / s 1 Paul Hsieh
CityHash64 1.05 GB / s 10 Pike & Alakuijala CityHash64 1.05 GB / s 10 Pike & Alakuijala
FNV 0.55 GB / s 5 Fowler , Noll , Vo FNV 0.55 GB / s 5 Fowler , Noll , Vo
CRC32 0.43 GB / s 9 CRC32 0.43 GB / s # 9
MD5 - 32 0.33 GB / s 10 Ronald L . Rivest MD5 - 32 0.33 GB / s 10 Ronald L . Rivest
SHA1 - 32 0.28 GB / s 10 SHA1 - 32 0.28 GB / s 10
Note # : other CRC32 implementations can be over 40 x faster than SMHasher ' s :
http : //fastcompression.blogspot.com/2019/03/presenting-xxh3.html?showComment=1552696407071#c3490092340461170735
Q . Score is a measure of quality of the hash function . Q . Score is a measure of quality of the hash function .
It depends on successfully passing SMHasher test set . It depends on successfully passing SMHasher test set .
10 is a perfect score . 10 is a perfect score .
*/
# pragma once A 64 - bit version , named XXH64 , is available since r35 .
It offers much better speed , but for 64 - bit 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
*/
# include <stdlib.h> # ifndef XXHASH_H_5627135585666179
# define XXHASH_H_5627135585666179 1
# if !defined(__VMS) && \ /* BEGIN RocksDB customizations */
( defined ( __cplusplus ) | | \
# ifndef XXH_STATIC_LINKING_ONLY
( defined ( __STDC_VERSION__ ) & & ( __STDC_VERSION__ > = 199901L ) /* C99 */ ) ) # define XXH_STATIC_LINKING_ONLY 1 /* access experimental APIs like XXH3 */
# include <stdint.h>
# endif # endif
# define XXH_NAMESPACE ROCKSDB_
/* END RocksDB customizations */
# if defined (__cplusplus) # if defined (__cplusplus)
namespace rocksdb { extern " C " {
# endif # endif
// ****************************
/* ****************************
// Type
* Definitions
//****************************
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* size_t */ # include <stddef.h> /* size_t */
typedef enum { XXH_OK = 0 , XXH_ERROR } XXH_errorcode ; typedef enum { XXH_OK = 0 , XXH_ERROR } XXH_errorcode ;
/* ****************************
* API modifier
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/** XXH_INLINE_ALL (and XXH_PRIVATE_API)
* This build macro includes xxhash functions in ` static ` mode
* in order to inline them , and remove their symbol from the public list .
* Inlining offers great performance improvement on small keys ,
* and dramatic ones when length is expressed as a compile - time constant .
* See https : //fastcompression.blogspot.com/2018/03/xxhash-for-small-keys-impressive-power.html .
* Methodology :
* # define XXH_INLINE_ALL
* # include " xxhash.h "
* ` xxhash . c ` is automatically included .
* It ' s not useful to compile and link it as a separate object .
*/
# if defined(XXH_INLINE_ALL) || defined(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
/* this version may generate warnings for unused static functions */
# define XXH_PUBLIC_API static
# endif
# else
# if defined(WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
# ifdef XXH_EXPORT
# define XXH_PUBLIC_API __declspec(dllexport)
# elif XXH_IMPORT
# define XXH_PUBLIC_API __declspec(dllimport)
# endif
# else
# define XXH_PUBLIC_API /* do nothing */
# endif
# endif /* XXH_INLINE_ALL || XXH_PRIVATE_API */
/*! XXH_NAMESPACE, aka Namespace Emulation :
*
* If you want to include _and expose_ xxHash functions from within your own library ,
* but also want to avoid symbol collisions with other libraries which may also include xxHash ,
*
* you can use XXH_NAMESPACE , to automatically prefix any public symbol from xxhash library
* with the value of XXH_NAMESPACE ( therefore , avoid NULL and numeric values ) .
*
* Note that no change is required within the calling program as long as it includes ` xxhash . h ` :
* regular symbol name will be automatically translated by this header .
*/
# ifdef XXH_NAMESPACE
# define XXH_CAT(A,B) A##B
# define XXH_NAME2(A,B) XXH_CAT(A,B)
# define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber)
# define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
# define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
# define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
# define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
# define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
# define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
# define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState)
# define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash)
# define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical)
# define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
# define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
# define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
# define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
# define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
# define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
# define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState)
# define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash)
# define XXH64_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH64_hashFromCanonical)
# endif
//****************************
// Simple Hash Functions
//****************************
unsigned int XXH32 ( const void * input , int len , unsigned int seed ) ; /* *************************************
* Version
/*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
XXH32 ( ) : # define XXH_VERSION_MAJOR 0
Calculate the 32 - bits hash of sequence of length " len " stored at memory address " input " . # define XXH_VERSION_MINOR 7
The memory between input & input + len must be valid ( allocated and read - accessible ) . # define XXH_VERSION_RELEASE 2
" seed " can be used to alter the result predictably . # define XXH_VERSION_NUMBER (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE)
This function successfully passes all SMHasher tests . XXH_PUBLIC_API unsigned XXH_versionNumber ( void ) ;
Speed on Core 2 Duo @ 3 GHz ( single thread , SMHasher benchmark ) : 5.4 GB / s
Note that " len " is type " int " , which means it is limited to 2 ^ 31 - 1.
If your data is larger , use the advanced functions below .
*/
/*-**********************************************************************
* 32 - bit hash
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
# if !defined (__VMS) \
& & ( defined ( __cplusplus ) \
| | ( defined ( __STDC_VERSION__ ) & & ( __STDC_VERSION__ > = 199901L ) /* C99 */ ) )
# include <stdint.h>
typedef uint32_t XXH32_hash_t ;
# else
# include <limits.h>
# if UINT_MAX == 0xFFFFFFFFUL
typedef unsigned int XXH32_hash_t ;
# else
# if ULONG_MAX == 0xFFFFFFFFUL
typedef unsigned long XXH32_hash_t ;
# else
# error "unsupported platform : need a 32-bit type"
# endif
# endif
# endif
//****************************
/*! XXH32() :
// Advanced Hash Functions
Calculate the 32 - bit hash of sequence " length " bytes stored at memory address " input " .
//****************************
The memory between input & input + length must be valid ( allocated and read - accessible ) .
" seed " can be used to alter the result predictably .
Speed on Core 2 Duo @ 3 GHz ( single thread , SMHasher benchmark ) : 5.4 GB / s */
XXH_PUBLIC_API XXH32_hash_t XXH32 ( const void * input , size_t length , XXH32_hash_t seed ) ;
void * XXH32_init ( unsigned int seed ) ; /*====== Streaming ======*/
XXH_errorcode XXH32_update ( void * state , const void * input , int len ) ;
unsigned int XXH32_digest ( void * state ) ;
/*
/*
These functions calculate the xxhash of an input provided in several small packets , * Streaming functions generate the xxHash value from an incrememtal input .
as opposed to an input provided as a single block . * This method is slower than single - call functions , due to state management .
* For small inputs , prefer ` XXH32 ( ) ` and ` XXH64 ( ) ` , which are better optimized .
It must be started with : *
void * XXH32_init ( ) * XXH state must first be allocated , using XXH * _createState ( ) .
The function returns a pointer which holds the state of calculation . *
* Start a new hash by initializing state with a seed , using XXH * _reset ( ) .
This pointer must be provided as " void* state " parameter for XXH32_update ( ) . *
XXH32_update ( ) can be called as many times as necessary . * Then , feed the hash state by calling XXH * _update ( ) as many times as necessary .
The user must provide a valid ( allocated ) input . * The function returns an error code , with 0 meaning OK , and any other value meaning there is an error .
The function returns an error code , with 0 meaning OK , and any other value meaning there is an error . *
Note that " len " is type " int " , which means it is limited to 2 ^ 31 - 1. * Finally , a hash value can be produced anytime , by using XXH * _digest ( ) .
If your data is larger , it is recommended to chunk your data into blocks * This function returns the nn - bits hash as an int or long long .
of size for example 2 ^ 30 ( 1 GB ) to avoid any " int " overflow issue . *
* It ' s still possible to continue inserting input into the hash state after a digest ,
Finally , you can end the calculation anytime , by using XXH32_digest ( ) . * and generate some new hash values later on , by invoking again XXH * _digest ( ) .
This function returns the final 32 - bits hash . *
You must provide the same " void* state " parameter created by XXH32_init ( ) . * When done , release the state , using XXH * _freeState ( ) .
Memory will be freed by XXH32_digest ( ) . */
*/
typedef struct XXH32_state_s XXH32_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 void XXH32_copyState ( XXH32_state_t * dst_state , const XXH32_state_t * src_state ) ;
XXH_PUBLIC_API XXH_errorcode XXH32_reset ( XXH32_state_t * statePtr , XXH32_hash_t 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 ) ;
int XXH32_sizeofState ( ) ; /*====== Canonical representation ======*/
XXH_errorcode XXH32_resetState ( void * state , unsigned int seed ) ;
# define XXH32_SIZEOFSTATE 48
typedef struct { long long ll [ ( XXH32_SIZEOFSTATE + ( sizeof ( long long ) - 1 ) ) / sizeof ( long long ) ] ; } XXH32_stateSpace_t ;
/*
These functions allow user application to make its own allocation for state .
XXH32_sizeofState ( ) is used to know how much space must be allocated for the xxHash 32 - bits state . /* Default return values from XXH functions are basic unsigned 32 and 64 bits.
Note that the state must be aligned to access ' long long ' fields . Memory must be allocated and referenced by a pointer . * This the simplest and fastest format for further post - processing .
This pointer must then be provided as ' state ' into XXH32_resetState ( ) , which initializes the state . * However , this leaves open the question of what is the order of bytes ,
* since little and big endian conventions will write the same number differently .
*
* The canonical representation settles this issue ,
* by mandating big - endian convention ,
* aka , the same convention as human - readable numbers ( large digits first ) .
* When writing hash values to storage , sending them over a network , or printing them ,
* it ' s highly recommended to use the canonical representation ,
* to ensure portability across a wider range of systems , present and future .
*
* The following functions allow transformation of hash values into and from canonical format .
*/
typedef struct { unsigned char digest [ 4 ] ; } XXH32_canonical_t ;
XXH_PUBLIC_API void XXH32_canonicalFromHash ( XXH32_canonical_t * dst , XXH32_hash_t hash ) ;
XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical ( const XXH32_canonical_t * src ) ;
# ifndef XXH_NO_LONG_LONG
/*-**********************************************************************
* 64 - bit hash
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
# if !defined (__VMS) \
& & ( defined ( __cplusplus ) \
| | ( defined ( __STDC_VERSION__ ) & & ( __STDC_VERSION__ > = 199901L ) /* C99 */ ) )
# include <stdint.h>
typedef uint64_t XXH64_hash_t ;
# else
/* the following type must have a width of 64-bit */
typedef unsigned long long XXH64_hash_t ;
# endif
For static allocation purposes ( such as allocation on stack , or freestanding systems without malloc ( ) ) , /*! XXH64() :
use the structure XXH32_stateSpace_t , which will ensure that memory space is large enough and correctly aligned to access ' long long ' fields . Calculate the 64 - bit hash of sequence of length " len " stored at memory address " input " .
" seed " can be used to alter the result predictably .
This function runs faster on 64 - bit systems , but slower on 32 - bit systems ( see benchmark ) .
*/ */
XXH_PUBLIC_API XXH64_hash_t XXH64 ( const void * input , size_t length , XXH64_hash_t seed ) ;
/*====== Streaming ======*/
typedef struct XXH64_state_s XXH64_state_t ; /* incomplete type */
XXH_PUBLIC_API XXH64_state_t * XXH64_createState ( void ) ;
XXH_PUBLIC_API XXH_errorcode XXH64_freeState ( XXH64_state_t * statePtr ) ;
XXH_PUBLIC_API void XXH64_copyState ( XXH64_state_t * dst_state , const XXH64_state_t * src_state ) ;
unsigned int XXH32_intermediateDigest ( void * state ) ; XXH_PUBLIC_API XXH_errorcode XXH64_reset ( XXH64_state_t * statePtr , XXH64_hash_t seed ) ;
/*
XXH_PUBLIC_API XXH_errorcode XXH64_update ( XXH64_state_t * statePtr , const void * input , size_t length ) ;
This function does the same as XXH32_digest ( ) , generating a 32 - bit hash , XXH_PUBLIC_API XXH64_hash_t XXH64_digest ( const XXH64_state_t * statePtr ) ;
but preserve memory context .
This way , it becomes possible to generate intermediate hashes , and then continue feeding data with XXH32_update ( ) .
To free memory context , use XXH32_digest ( ) , or free ( ) .
*/
/*====== Canonical representation ======*/
typedef struct { unsigned char digest [ 8 ] ; } XXH64_canonical_t ;
XXH_PUBLIC_API void XXH64_canonicalFromHash ( XXH64_canonical_t * dst , XXH64_hash_t hash ) ;
XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical ( const XXH64_canonical_t * src ) ;
//****************************
// Deprecated function names
//****************************
// The following translations are provided to ease code transition
// You are encouraged to no longer this function names
# define XXH32_feed XXH32_update
# define XXH32_result XXH32_digest
# define XXH32_getIntermediateResult XXH32_intermediateDigest
/*-**********************************************************************
# endif /* XXH_NO_LONG_LONG */
* 64 - bit hash
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
typedef unsigned long long XXH64_hash_t ;
/*! XXH64() :
Calculate the 64 - bit hash of sequence of length " len " stored at memory
address " input " . " seed " can be used to alter the result predictably . This
function runs faster on 64 - bit systems , but slower on 32 - bit systems ( see
benchmark ) .
*/
XXH64_hash_t XXH64 ( const void * input , size_t length , unsigned long long seed ) ;
/*====== Streaming ======*/
typedef struct XXH64_state_s XXH64_state_t ; /* incomplete type */
XXH64_state_t * XXH64_createState ( void ) ;
XXH_errorcode XXH64_freeState ( XXH64_state_t * statePtr ) ;
void XXH64_copyState ( XXH64_state_t * dst_state , const XXH64_state_t * src_state ) ;
XXH_errorcode XXH64_reset ( XXH64_state_t * statePtr , unsigned long long seed ) ; # ifdef XXH_STATIC_LINKING_ONLY
XXH_errorcode XXH64_update ( XXH64_state_t * statePtr , const void * input ,
size_t length ) ;
XXH64_hash_t XXH64_digest ( const XXH64_state_t * statePtr ) ;
/*====== Canonical representation ======*/ /* ================================================================================================
typedef struct { This section contains declarations which are not guaranteed to remain stable .
unsigned char digest [ 8 ] ; They may change in future versions , becoming incompatible with a different version of the library .
} XXH64_canonical_t ; These declarations should only be used with static linking .
void XXH64_canonicalFromHash ( XXH64_canonical_t * dst , XXH64_hash_t hash ) ; Never use them in association with dynamic linking !
XXH64_hash_t XXH64_hashFromCanonical ( const XXH64_canonical_t * src ) ; = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = */
/* These definitions are only present to allow
/* These definitions are only present to allow
* static allocation of XXH state , on stack or in a struct for example . * static allocation of XXH state , on stack or in a struct for example .
* Never * * ever * * use members directly . */ * Never * * ever * * use members directly . */
# if !defined(__VMS) && \ struct XXH32_state_s {
( defined ( __cplusplus ) | | \
XXH32_hash_t total_len_32 ;
( defined ( __STDC_VERSION__ ) & & ( __STDC_VERSION__ > = 199901L ) /* C99 */ ) ) XXH32_hash_t large_len ;
XXH32_hash_t v1 ;
XXH32_hash_t v2 ;
XXH32_hash_t v3 ;
XXH32_hash_t v4 ;
XXH32_hash_t mem32 [ 4 ] ;
XXH32_hash_t memsize ;
XXH32_hash_t reserved ; /* never read nor write, might be removed in a future version */
} ; /* typedef'd to XXH32_state_t */
# ifndef XXH_NO_LONG_LONG /* remove 64-bit support */
struct XXH64_state_s { struct XXH64_state_s {
uint64_t total_len ; XXH64_hash _t total_len ;
uint64_t v1 ; XXH64_hash _t v1 ;
uint64_t v2 ; XXH64_hash _t v2 ;
uint64_t v3 ; XXH64_hash _t v3 ;
uint64_t v4 ; XXH64_hash _t v4 ;
uint64_t mem64 [ 4 ] ; XXH64_hash _t mem64 [ 4 ] ;
uint32 _tmemsize ; XXH32_hash _t memsize ;
uint32_t reserved [ 2 ] ; /* never read nor write, might be removed in a future
XXH32_hash_t reserved32 ; /* required for padding anyway */
version */ XXH64_hash_t reserved64 ; /* never read nor write, might be removed in a future version */
} ; /* typedef'd to XXH64_state_t */ } ; /* typedef'd to XXH64_state_t */
# endif /* XXH_NO_LONG_LONG */
/*-**********************************************************************
* XXH3
* New experimental hash
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
# ifndef XXH_NO_LONG_LONG
/* ============================================
* XXH3 is a new hash algorithm ,
* featuring improved speed performance for both small and large inputs .
* See full speed analysis at : http : //fastcompression.blogspot.com/2019/03/presenting-xxh3.html
* In general , expect XXH3 to run about ~ 2 x faster on large inputs ,
* and > 3 x faster on small ones , though exact differences depend on platform .
*
* The algorithm is portable , will generate the same hash on all platforms .
* It benefits greatly from vectorization units , but does not require it .
*
* XXH3 offers 2 variants , _64bits and _128bits .
* When only 64 bits are needed , prefer calling the _64bits variant :
* it reduces the amount of mixing , resulting in faster speed on small inputs .
* It ' s also generally simpler to manipulate a scalar return type than a struct .
*
* The XXH3 algorithm is still considered experimental .
* Produced results can still change between versions .
* Results produced by v0 .7 . x are not comparable with results from v0 .7 . y .
* It ' s nonetheless possible to use XXH3 for ephemeral data ( local sessions ) ,
* but avoid storing values in long - term storage for later reads .
*
* The API supports one - shot hashing , streaming mode , and custom secrets .
*
* There are still a number of opened questions that community can influence during the experimental period .
* I ' m trying to list a few of them below , though don ' t consider this list as complete .
*
* - 128 - bits output type : currently defined as a structure of two 64 - bits fields .
* That ' s because 128 - bit values do not exist in C standard .
* Note that it means that , at byte level , result is not identical depending on endianess .
* However , at field level , they are identical on all platforms .
* The canonical representation solves the issue of identical byte - level representation across platforms ,
* which is necessary for serialization .
* Q1 : Would there be a better representation for a 128 - bit hash result ?
* Q2 : Are the names of the inner 64 - bit fields important ? Should they be changed ?
*
* - Prototype XXH128 ( ) : XXH128 ( ) uses the same arguments as XXH64 ( ) , for consistency .
* It means it maps to XXH3p_128bits_withSeed ( ) .
* This variant is slightly slower than XXH3p_128bits ( ) ,
* because the seed is now part of the algorithm , and can ' t be simplified .
* Is that a good idea ?
*
* - Seed type for XXH128 ( ) : currently , it ' s a single 64 - bit value , like the 64 - bit variant .
* It could be argued that it ' s more logical to offer a 128 - bit seed input parameter for a 128 - bit hash .
* But 128 - bit seed is more difficult to use , since it requires to pass a structure instead of a scalar value .
* Such a variant could either replace current one , or become an additional one .
* Farmhash , for example , offers both variants ( the 128 - bits seed variant is called ` doubleSeed ` ) .
* Follow up question : if both 64 - bit and 128 - bit seeds are allowed , which variant should be called XXH128 ?
*
* - Result for len = = 0 : Currently , the result of hashing a zero - length input is always ` 0 ` .
* It seems okay as a return value when using " default " secret and seed .
* But is it still fine to return ` 0 ` when secret or seed are non - default ?
* Are there use cases which could depend on generating a different hash result for zero - length input when the secret is different ?
*
* - Consistency ( 1 ) : Streaming XXH128 uses an XXH3 state , which is the same state as XXH3p_64bits ( ) .
* It means a 128 bit streaming loop must invoke the following symbols :
* XXH3p_createState ( ) , XXH3p_128bits_reset ( ) , XXH3p_128bits_update ( ) ( loop ) , XXH3p_128bits_digest ( ) , XXH3p_freeState ( ) .
* Is that consistent enough ?
*
* - Consistency ( 2 ) : The canonical representation of ` XXH3p_64bits ` is provided by existing functions
* XXH64_canonicalFromHash ( ) , and reverse operation XXH64_hashFromCanonical ( ) .
* As a mirror , canonical functions for XXH128_hash_t results generated by ` XXH3p_128bits `
* are XXH128_canonicalFromHash ( ) and XXH128_hashFromCanonical ( ) .
* Which means , ` XXH3 ` doesn ' t appear in the names , because canonical functions operate on a type ,
* independently of which algorithm was used to generate that type .
* Is that consistent enough ?
*/
# ifdef XXH_NAMESPACE
# define XXH3p_64bits XXH_NAME2(XXH_NAMESPACE, XXH3p_64bits)
# define XXH3p_64bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3p_64bits_withSecret)
# define XXH3p_64bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3p_64bits_withSeed)
# define XXH3p_createState XXH_NAME2(XXH_NAMESPACE, XXH3p_createState)
# define XXH3p_freeState XXH_NAME2(XXH_NAMESPACE, XXH3p_freeState)
# define XXH3p_copyState XXH_NAME2(XXH_NAMESPACE, XXH3p_copyState)
# define XXH3p_64bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3p_64bits_reset)
# define XXH3p_64bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3p_64bits_reset_withSeed)
# define XXH3p_64bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3p_64bits_reset_withSecret)
# define XXH3p_64bits_update XXH_NAME2(XXH_NAMESPACE, XXH3p_64bits_update)
# define XXH3p_64bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3p_64bits_digest)
# endif
/* XXH3p_64bits() :
* default 64 - bit variant , using default secret and default seed of 0.
* It ' s the fastest variant . */
XXH_PUBLIC_API XXH64_hash_t XXH3p_64bits ( const void * data , size_t len ) ;
/* XXH3p_64bits_withSecret() :
* It ' s possible to provide any blob of bytes as a " secret " to generate the hash .
* This makes it more difficult for an external actor to prepare an intentional collision .
* The secret * must * be large enough ( > = XXH3p_SECRET_SIZE_MIN ) .
* It should consist of random bytes .
* Avoid repeating same character , or sequences of bytes ,
* and especially avoid swathes of \ 0.
* Failure to respect these conditions will result in a poor quality hash .
*/
# define XXH3p_SECRET_SIZE_MIN 136
XXH_PUBLIC_API XXH64_hash_t XXH3p_64bits_withSecret ( const void * data , size_t len , const void * secret , size_t secretSize ) ;
/* XXH3p_64bits_withSeed() :
* This variant generates on the fly a custom secret ,
* based on the default secret , altered using the ` seed ` value .
* While this operation is decently fast , note that it ' s not completely free .
* note : seed = = 0 produces same results as XXH3p_64bits ( ) */
XXH_PUBLIC_API XXH64_hash_t XXH3p_64bits_withSeed ( const void * data , size_t len , XXH64_hash_t seed ) ;
/* streaming 64-bit */
# if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) /* C11+ */
# include <stdalign.h>
# define XXH_ALIGN(n) alignas(n)
# elif defined(__GNUC__)
# define XXH_ALIGN(n) __attribute__ ((aligned(n)))
# elif defined(_MSC_VER)
# define XXH_ALIGN(n) __declspec(align(n))
# else # else
# define XXH_ALIGN(n) /* disabled */
# endif
# ifndef XXH_NO_LONG_LONG /* remove 64-bit support */ typedef struct XXH3p_state_s XXH3p_state_t ;
struct XXH64_state_s {
unsigned long long total_len ; # define XXH3p_SECRET_DEFAULT_SIZE 192 /* minimum XXH3p_SECRET_SIZE_MIN */
unsigned long long v1 ; # define XXH3p_INTERNALBUFFER_SIZE 256
unsigned long long v2 ; struct XXH3p_state_s {
unsigned long long v3 ; XXH_ALIGN ( 64 ) XXH64_hash_t acc [ 8 ] ;
unsigned long long v4 ; XXH_ALIGN ( 64 ) unsigned char customSecret [ XXH3p_SECRET_DEFAULT_SIZE ] ; /* used to store a custom secret generated from the seed. Makes state larger. Design might change */
unsigned long long mem64 [ 4 ] ; XXH_ALIGN ( 64 ) unsigned char buffer [ XXH3p_INTERNALBUFFER_SIZE ] ;
unsigned memsize ; XXH32_hash_t bufferedSize ;
unsigned reserved [ 2 ] ; /* never read nor write, might be removed in a future
XXH32_hash_t nbStripesPerBlock ;
version */ XXH32_hash_t nbStripesSoFar ;
} ; /* typedef'd to XXH64_state_t */ XXH32_hash_t secretLimit ;
XXH32_hash_t reserved32 ;
XXH32_hash_t reserved32_2 ;
XXH64_hash_t totalLen ;
XXH64_hash_t seed ;
XXH64_hash_t reserved64 ;
const unsigned char * secret ; /* note : there is some padding after, due to alignment on 64 bytes */
} ; /* typedef'd to XXH3p_state_t */
/* Streaming requires state maintenance.
* This operation costs memory and cpu .
* As a consequence , streaming is slower than one - shot hashing .
* For better performance , prefer using one - shot functions whenever possible . */
XXH_PUBLIC_API XXH3p_state_t * XXH3p_createState ( void ) ;
XXH_PUBLIC_API XXH_errorcode XXH3p_freeState ( XXH3p_state_t * statePtr ) ;
XXH_PUBLIC_API void XXH3p_copyState ( XXH3p_state_t * dst_state , const XXH3p_state_t * src_state ) ;
/* XXH3p_64bits_reset() :
* initialize with default parameters .
* result will be equivalent to ` XXH3p_64bits ( ) ` . */
XXH_PUBLIC_API XXH_errorcode XXH3p_64bits_reset ( XXH3p_state_t * statePtr ) ;
/* XXH3p_64bits_reset_withSeed() :
* generate a custom secret from ` seed ` , and store it into state .
* digest will be equivalent to ` XXH3p_64bits_withSeed ( ) ` . */
XXH_PUBLIC_API XXH_errorcode XXH3p_64bits_reset_withSeed ( XXH3p_state_t * statePtr , XXH64_hash_t seed ) ;
/* XXH3p_64bits_reset_withSecret() :
* ` secret ` is referenced , and must outlive the hash streaming session .
* secretSize must be > = XXH3p_SECRET_SIZE_MIN .
*/
XXH_PUBLIC_API XXH_errorcode XXH3p_64bits_reset_withSecret ( XXH3p_state_t * statePtr , const void * secret , size_t secretSize ) ;
XXH_PUBLIC_API XXH_errorcode XXH3p_64bits_update ( XXH3p_state_t * statePtr , const void * input , size_t length ) ;
XXH_PUBLIC_API XXH64_hash_t XXH3p_64bits_digest ( const XXH3p_state_t * statePtr ) ;
/* 128-bit */
# ifdef XXH_NAMESPACE
# define XXH128 XXH_NAME2(XXH_NAMESPACE, XXH128)
# define XXH3p_128bits XXH_NAME2(XXH_NAMESPACE, XXH3p_128bits)
# define XXH3p_128bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3p_128bits_withSeed)
# define XXH3p_128bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3p_128bits_withSecret)
# define XXH3p_128bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3p_128bits_reset)
# define XXH3p_128bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3p_128bits_reset_withSeed)
# define XXH3p_128bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3p_128bits_reset_withSecret)
# define XXH3p_128bits_update XXH_NAME2(XXH_NAMESPACE, XXH3p_128bits_update)
# define XXH3p_128bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3p_128bits_digest)
# define XXH128_isEqual XXH_NAME2(XXH_NAMESPACE, XXH128_isEqual)
# define XXH128_cmp XXH_NAME2(XXH_NAMESPACE, XXH128_cmp)
# define XXH128_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH128_canonicalFromHash)
# define XXH128_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH128_hashFromCanonical)
# endif # endif
typedef struct {
XXH64_hash_t low64 ;
XXH64_hash_t high64 ;
} XXH128_hash_t ;
XXH_PUBLIC_API XXH128_hash_t XXH128 ( const void * data , size_t len , XXH64_hash_t seed ) ;
XXH_PUBLIC_API XXH128_hash_t XXH3p_128bits ( const void * data , size_t len ) ;
XXH_PUBLIC_API XXH128_hash_t XXH3p_128bits_withSeed ( const void * data , size_t len , XXH64_hash_t seed ) ; /* == XXH128() */
XXH_PUBLIC_API XXH128_hash_t XXH3p_128bits_withSecret ( const void * data , size_t len , const void * secret , size_t secretSize ) ;
XXH_PUBLIC_API XXH_errorcode XXH3p_128bits_reset ( XXH3p_state_t * statePtr ) ;
XXH_PUBLIC_API XXH_errorcode XXH3p_128bits_reset_withSeed ( XXH3p_state_t * statePtr , XXH64_hash_t seed ) ;
XXH_PUBLIC_API XXH_errorcode XXH3p_128bits_reset_withSecret ( XXH3p_state_t * statePtr , const void * secret , size_t secretSize ) ;
XXH_PUBLIC_API XXH_errorcode XXH3p_128bits_update ( XXH3p_state_t * statePtr , const void * input , size_t length ) ;
XXH_PUBLIC_API XXH128_hash_t XXH3p_128bits_digest ( const XXH3p_state_t * statePtr ) ;
/* Note : for better performance, following functions can be inlined,
* using XXH_INLINE_ALL */
/* return : 1 is equal, 0 if different */
XXH_PUBLIC_API int XXH128_isEqual ( XXH128_hash_t h1 , XXH128_hash_t h2 ) ;
/* This comparator is compatible with stdlib's qsort().
* return : > 0 if * h128_1 > * h128_2
* < 0 if * h128_1 < * h128_2
* = 0 if * h128_1 = = * h128_2 */
XXH_PUBLIC_API int XXH128_cmp ( const void * h128_1 , const void * h128_2 ) ;
/*====== Canonical representation ======*/
typedef struct { unsigned char digest [ 16 ] ; } XXH128_canonical_t ;
XXH_PUBLIC_API void XXH128_canonicalFromHash ( XXH128_canonical_t * dst , XXH128_hash_t hash ) ;
XXH_PUBLIC_API XXH128_hash_t XXH128_hashFromCanonical ( const XXH128_canonical_t * src ) ;
# endif /* XXH_NO_LONG_LONG */
/*-**********************************************************************
* XXH_INLINE_ALL
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
# if defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API)
# include "xxhash.cc" /* include xxhash function bodies as `static`, for inlining */
# endif # endif
# endif /* XXH_STATIC_LINKING_ONLY */
# if defined (__cplusplus) # if defined (__cplusplus)
} // namespace rocksdb
}
# endif # endif
# endif /* XXHASH_H_5627135585666179 */
Peter Dillinger
5 years ago
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