1 /* 2 xxHash - Extremely Fast Hash algorithm 3 Header File 4 Copyright (C) 2012-2014, Yann Collet. 5 BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) 6 7 Redistribution and use in source and binary forms, with or without 8 modification, are permitted provided that the following conditions are 9 met: 10 11 * Redistributions of source code must retain the above copyright 12 notice, this list of conditions and the following disclaimer. 13 * Redistributions in binary form must reproduce the above 14 copyright notice, this list of conditions and the following disclaimer 15 in the documentation and/or other materials provided with the 16 distribution. 17 18 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30 You can contact the author at : 31 - xxHash source repository : http://code.google.com/p/xxhash/ 32 */ 33 34 /* Notice extracted from xxHash homepage : 35 36 xxHash is an extremely fast Hash algorithm, running at RAM speed limits. 37 It also successfully passes all tests from the SMHasher suite. 38 39 Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz) 40 41 Name Speed Q.Score Author 42 xxHash 5.4 GB/s 10 43 CrapWow 3.2 GB/s 2 Andrew 44 MumurHash 3a 2.7 GB/s 10 Austin Appleby 45 SpookyHash 2.0 GB/s 10 Bob Jenkins 46 SBox 1.4 GB/s 9 Bret Mulvey 47 Lookup3 1.2 GB/s 9 Bob Jenkins 48 SuperFastHash 1.2 GB/s 1 Paul Hsieh 49 CityHash64 1.05 GB/s 10 Pike & Alakuijala 50 FNV 0.55 GB/s 5 Fowler, Noll, Vo 51 CRC32 0.43 GB/s 9 52 MD5-32 0.33 GB/s 10 Ronald L. Rivest 53 SHA1-32 0.28 GB/s 10 54 55 Q.Score is a measure of quality of the hash function. 56 It depends on successfully passing SMHasher test set. 57 10 is a perfect score. 58 */ 59 60 #pragma once 61 62 #if defined (__cplusplus) 63 extern "C" { 64 #endif 65 66 67 /***************************** 68 Includes 69 *****************************/ 70 #include <stddef.h> /* size_t */ 71 72 73 /***************************** 74 Type 75 *****************************/ 76 typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode; 77 78 79 80 /***************************** 81 Simple Hash Functions 82 *****************************/ 83 84 unsigned int XXH32 (const void* input, size_t length, unsigned seed); 85 unsigned long long XXH64 (const void* input, size_t length, unsigned long long seed); 86 87 /* 88 XXH32() : 89 Calculate the 32-bits hash of sequence "length" bytes stored at memory address "input". 90 The memory between input & input+length must be valid (allocated and read-accessible). 91 "seed" can be used to alter the result predictably. 92 This function successfully passes all SMHasher tests. 93 Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s 94 XXH64() : 95 Calculate the 64-bits hash of sequence of length "len" stored at memory address "input". 96 */ 97 98 99 100 /***************************** 101 Advanced Hash Functions 102 *****************************/ 103 typedef struct { long long ll[ 6]; } XXH32_state_t; 104 typedef struct { long long ll[11]; } XXH64_state_t; 105 106 /* 107 These structures allow static allocation of XXH states. 108 States must then be initialized using XXHnn_reset() before first use. 109 110 If you prefer dynamic allocation, please refer to functions below. 111 */ 112 113 XXH32_state_t* XXH32_createState(void); 114 XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr); 115 116 XXH64_state_t* XXH64_createState(void); 117 XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr); 118 119 /* 120 These functions create and release memory for XXH state. 121 States must then be initialized using XXHnn_reset() before first use. 122 */ 123 124 125 XXH_errorcode XXH32_reset (XXH32_state_t* statePtr, unsigned seed); 126 XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length); 127 unsigned int XXH32_digest (const XXH32_state_t* statePtr); 128 129 XXH_errorcode XXH64_reset (XXH64_state_t* statePtr, unsigned long long seed); 130 XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length); 131 unsigned long long XXH64_digest (const XXH64_state_t* statePtr); 132 133 /* 134 These functions calculate the xxHash of an input provided in multiple smaller packets, 135 as opposed to an input provided as a single block. 136 137 XXH state space must first be allocated, using either static or dynamic method provided above. 138 139 Start a new hash by initializing state with a seed, using XXHnn_reset(). 140 141 Then, feed the hash state by calling XXHnn_update() as many times as necessary. 142 Obviously, input must be valid, meaning allocated and read accessible. 143 The function returns an error code, with 0 meaning OK, and any other value meaning there is an error. 144 145 Finally, you can produce a hash anytime, by using XXHnn_digest(). 146 This function returns the final nn-bits hash. 147 You can nonetheless continue feeding the hash state with more input, 148 and therefore get some new hashes, by calling again XXHnn_digest(). 149 150 When you are done, don't forget to free XXH state space, using typically XXHnn_freeState(). 151 */ 152 153 154 #if defined (__cplusplus) 155 } 156 #endif 157
