fork of https://github.com/oxigraph/rocksdb and https://github.com/facebook/rocksdb for nextgraph and oxigraph
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
164 lines
6.2 KiB
164 lines
6.2 KiB
/*
|
|
xxHash - Fast Hash algorithm
|
|
Header File
|
|
Copyright (C) 2012-2014, Yann Collet.
|
|
BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are
|
|
met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
* Redistributions in binary form must reproduce the above
|
|
copyright notice, this list of conditions and the following disclaimer
|
|
in the documentation and/or other materials provided with the
|
|
distribution.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
You can contact the author at :
|
|
- xxHash source repository : http://code.google.com/p/xxhash/
|
|
*/
|
|
|
|
/* 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.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#if defined (__cplusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
|
|
//****************************
|
|
// Type
|
|
//****************************
|
|
typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode;
|
|
|
|
|
|
|
|
//****************************
|
|
// Simple Hash Functions
|
|
//****************************
|
|
|
|
unsigned int XXH32 (const void* input, int len, unsigned int seed);
|
|
|
|
/*
|
|
XXH32() :
|
|
Calculate the 32-bits hash of sequence of length "len" stored at memory address "input".
|
|
The memory between input & input+len must be valid (allocated and read-accessible).
|
|
"seed" can be used to alter the result predictably.
|
|
This function successfully passes all SMHasher tests.
|
|
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.
|
|
*/
|
|
|
|
|
|
|
|
//****************************
|
|
// Advanced Hash Functions
|
|
//****************************
|
|
|
|
void* XXH32_init (unsigned int seed);
|
|
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,
|
|
as opposed to an input provided as a single block.
|
|
|
|
It must be started with :
|
|
void* XXH32_init()
|
|
The function returns a pointer which holds the state of calculation.
|
|
|
|
This pointer must be provided as "void* state" parameter for XXH32_update().
|
|
XXH32_update() can be called 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.
|
|
Note that "len" is type "int", which means it is limited to 2^31-1.
|
|
If your data is larger, it is recommended to chunk your data into blocks
|
|
of size for example 2^30 (1GB) to avoid any "int" overflow issue.
|
|
|
|
Finally, you can end the calculation anytime, by using XXH32_digest().
|
|
This function returns the final 32-bits hash.
|
|
You must provide the same "void* state" parameter created by XXH32_init().
|
|
Memory will be freed by XXH32_digest().
|
|
*/
|
|
|
|
|
|
int XXH32_sizeofState();
|
|
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.
|
|
Note that the state must be aligned to access 'long long' fields. Memory must be allocated and referenced by a pointer.
|
|
This pointer must then be provided as 'state' into XXH32_resetState(), which initializes the state.
|
|
|
|
For static allocation purposes (such as allocation on stack, or freestanding systems without malloc()),
|
|
use the structure XXH32_stateSpace_t, which will ensure that memory space is large enough and correctly aligned to access 'long long' fields.
|
|
*/
|
|
|
|
|
|
unsigned int XXH32_intermediateDigest (void* state);
|
|
/*
|
|
This function does the same as XXH32_digest(), generating a 32-bit hash,
|
|
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().
|
|
*/
|
|
|
|
|
|
|
|
//****************************
|
|
// 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
|
|
|
|
|
|
|
|
#if defined (__cplusplus)
|
|
}
|
|
#endif
|
|
|