/* * xxHash - Extremely Fast Hash algorithm * Copyright (C) 2012-2016, 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. * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License version 2 as published by the * Free Software Foundation. This program is dual-licensed; you may select * either version 2 of the GNU General Public License ("GPL") or BSD license * ("BSD"). * * You can contact the author at: * - xxHash homepage: https://cyan4973.github.io/xxHash/ * - xxHash source repository: https://github.com/Cyan4973/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. * * A 64-bits version, named xxh64 offers much better speed, * but for 64-bits 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 */ #ifndef XXHASH_H #define XXHASH_H #include <linux/types.h> /*-**************************** * Simple Hash Functions *****************************/ /** * xxh32() - calculate the 32-bit hash of the input with a given seed. * * @input: The data to hash. * @length: The length of the data to hash. * @seed: The seed can be used to alter the result predictably. * * Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s * * Return: The 32-bit hash of the data. */ uint32_t xxh32(const void *input, size_t length, uint32_t seed); /** * xxh64() - calculate the 64-bit hash of the input with a given seed. * * @input: The data to hash. * @length: The length of the data to hash. * @seed: The seed can be used to alter the result predictably. * * This function runs 2x faster on 64-bit systems, but slower on 32-bit systems. * * Return: The 64-bit hash of the data. */ uint64_t xxh64(const void *input, size_t length, uint64_t seed); /** * xxhash() - calculate wordsize hash of the input with a given seed * @input: The data to hash. * @length: The length of the data to hash. * @seed: The seed can be used to alter the result predictably. * * If the hash does not need to be comparable between machines with * different word sizes, this function will call whichever of xxh32() * or xxh64() is faster. * * Return: wordsize hash of the data. */ static inline unsigned long xxhash(const void *input, size_t length, uint64_t seed) { … } /*-**************************** * Streaming Hash Functions *****************************/ /* * These definitions are only meant to allow allocation of XXH state * statically, on stack, or in a struct for example. * Do not use members directly. */ /** * struct xxh32_state - private xxh32 state, do not use members directly */ struct xxh32_state { … }; /** * struct xxh32_state - private xxh64 state, do not use members directly */ struct xxh64_state { … }; /** * xxh32_reset() - reset the xxh32 state to start a new hashing operation * * @state: The xxh32 state to reset. * @seed: Initialize the hash state with this seed. * * Call this function on any xxh32_state to prepare for a new hashing operation. */ void xxh32_reset(struct xxh32_state *state, uint32_t seed); /** * xxh32_update() - hash the data given and update the xxh32 state * * @state: The xxh32 state to update. * @input: The data to hash. * @length: The length of the data to hash. * * After calling xxh32_reset() call xxh32_update() as many times as necessary. * * Return: Zero on success, otherwise an error code. */ int xxh32_update(struct xxh32_state *state, const void *input, size_t length); /** * xxh32_digest() - produce the current xxh32 hash * * @state: Produce the current xxh32 hash of this state. * * A hash value can be produced at any time. It is still possible to continue * inserting input into the hash state after a call to xxh32_digest(), and * generate new hashes later on, by calling xxh32_digest() again. * * Return: The xxh32 hash stored in the state. */ uint32_t xxh32_digest(const struct xxh32_state *state); /** * xxh64_reset() - reset the xxh64 state to start a new hashing operation * * @state: The xxh64 state to reset. * @seed: Initialize the hash state with this seed. */ void xxh64_reset(struct xxh64_state *state, uint64_t seed); /** * xxh64_update() - hash the data given and update the xxh64 state * @state: The xxh64 state to update. * @input: The data to hash. * @length: The length of the data to hash. * * After calling xxh64_reset() call xxh64_update() as many times as necessary. * * Return: Zero on success, otherwise an error code. */ int xxh64_update(struct xxh64_state *state, const void *input, size_t length); /** * xxh64_digest() - produce the current xxh64 hash * * @state: Produce the current xxh64 hash of this state. * * A hash value can be produced at any time. It is still possible to continue * inserting input into the hash state after a call to xxh64_digest(), and * generate new hashes later on, by calling xxh64_digest() again. * * Return: The xxh64 hash stored in the state. */ uint64_t xxh64_digest(const struct xxh64_state *state); /*-************************** * Utils ***************************/ /** * xxh32_copy_state() - copy the source state into the destination state * * @src: The source xxh32 state. * @dst: The destination xxh32 state. */ void xxh32_copy_state(struct xxh32_state *dst, const struct xxh32_state *src); /** * xxh64_copy_state() - copy the source state into the destination state * * @src: The source xxh64 state. * @dst: The destination xxh64 state. */ void xxh64_copy_state(struct xxh64_state *dst, const struct xxh64_state *src); #endif /* XXHASH_H */
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