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