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Iterator/zstd/common/xxhash.h  view on Meta::CPAN

#  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);

/*!
XXH32() :
    Calculate the 32-bits 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
XXH64() :
    Calculate the 64-bits hash of sequence of length "len" stored at memory address "input".
    "seed" can be used to alter the result predictably.
    This function runs 2x faster on 64-bits systems, but slower on 32-bits systems (see benchmark).
*/


/* ****************************
*  Streaming Hash Functions
******************************/
typedef struct XXH32_state_s XXH32_state_t;   /* incomplete type */
typedef struct XXH64_state_s XXH64_state_t;   /* incomplete type */

/*! State allocation, compatible with dynamic libraries */

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
****************************/
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);

/* 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.
*/