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![Timofey Titovets](/assets/img/avatar_default.png)
Patch series "Currently used jhash are slow enough and replace it allow as to make KSM", v8. Apeed (in kernel): ksm: crc32c hash() 12081 MB/s ksm: xxh64 hash() 8770 MB/s ksm: xxh32 hash() 4529 MB/s ksm: jhash2 hash() 1569 MB/s Sioh Lee's testing (copy from other mail): Test platform: openstack cloud platform (NEWTON version) Experiment node: openstack based cloud compute node (CPU: xeon E5-2620 v3, memory 64gb) VM: (2 VCPU, RAM 4GB, DISK 20GB) * 4 Linux kernel: 4.14 (latest version) KSM setup - sleep_millisecs: 200ms, pages_to_scan: 200 Experiment process: Firstly, we turn off KSM and launch 4 VMs. Then we turn on the KSM and measure the checksum computation time until full_scans become two. The experimental results (the experimental value is the average of the measured values) crc32c_intel: 1084.10ns crc32c (no hardware acceleration): 7012.51ns xxhash32: 2227.75ns xxhash64: 1413.16ns jhash2: 5128.30ns In summary, the result shows that crc32c_intel has advantages over all of the hash function used in the experiment. (decreased by 84.54% compared to crc32c, 78.86% compared to jhash2, 51.33% xxhash32, 23.28% compared to xxhash64) the results are similar to those of Timofey. But, use only xxhash for now, because for using crc32c, cryptoapi must be initialized first - that require some tricky solution to work good in all situations. So: - First patch implement compile time pickup of fastest implementation of xxhash for target platform. - The second patch replaces jhash2 with xxhash This patch (of 2): xxh32() - fast on both 32/64-bit platforms xxh64() - fast only on 64-bit platform Create xxhash() which will pick up the fastest version at compile time. Link: http://lkml.kernel.org/r/20181023182554.23464-2-nefelim4ag@gmail.com Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: leesioh <solee@os.korea.ac.kr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
259 lines
8.3 KiB
C
259 lines
8.3 KiB
C
/*
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* xxHash - Extremely Fast Hash algorithm
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* Copyright (C) 2012-2016, Yann Collet.
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*
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* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following disclaimer
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* in the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* This program is free software; you can redistribute it and/or modify it under
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* the terms of the GNU General Public License version 2 as published by the
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* Free Software Foundation. This program is dual-licensed; you may select
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* either version 2 of the GNU General Public License ("GPL") or BSD license
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* ("BSD").
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*
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* You can contact the author at:
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* - xxHash homepage: http://cyan4973.github.io/xxHash/
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* - xxHash source repository: https://github.com/Cyan4973/xxHash
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*/
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/*
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* Notice extracted from xxHash homepage:
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*
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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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*
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* Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2
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* Duo @3GHz)
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*
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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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*
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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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*
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* A 64-bits version, named xxh64 offers much better speed,
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* 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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#ifndef XXHASH_H
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#define XXHASH_H
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#include <linux/types.h>
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/*-****************************
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* Simple Hash Functions
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*****************************/
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/**
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* xxh32() - calculate the 32-bit hash of the input with a given seed.
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*
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* @input: The data to hash.
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* @length: The length of the data to hash.
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* @seed: The seed can be used to alter the result predictably.
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*
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* Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
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*
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* Return: The 32-bit hash of the data.
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*/
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uint32_t xxh32(const void *input, size_t length, uint32_t seed);
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/**
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* xxh64() - calculate the 64-bit hash of the input with a given seed.
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*
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* @input: The data to hash.
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* @length: The length of the data to hash.
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* @seed: The seed can be used to alter the result predictably.
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*
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* This function runs 2x faster on 64-bit systems, but slower on 32-bit systems.
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*
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* Return: The 64-bit hash of the data.
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*/
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uint64_t xxh64(const void *input, size_t length, uint64_t seed);
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/**
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* xxhash() - calculate wordsize hash of the input with a given seed
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* @input: The data to hash.
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* @length: The length of the data to hash.
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* @seed: The seed can be used to alter the result predictably.
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*
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* If the hash does not need to be comparable between machines with
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* different word sizes, this function will call whichever of xxh32()
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* or xxh64() is faster.
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*
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* Return: wordsize hash of the data.
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*/
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static inline unsigned long xxhash(const void *input, size_t length,
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uint64_t seed)
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{
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#if BITS_PER_LONG == 64
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return xxh64(input, length, seed);
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#else
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return xxh32(input, length, seed);
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#endif
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}
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/*-****************************
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* Streaming Hash Functions
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*****************************/
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/*
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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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*/
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/**
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* struct xxh32_state - private xxh32 state, do not use members directly
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*/
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struct xxh32_state {
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uint32_t total_len_32;
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uint32_t large_len;
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uint32_t v1;
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uint32_t v2;
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uint32_t v3;
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uint32_t v4;
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uint32_t mem32[4];
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uint32_t memsize;
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};
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/**
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* struct xxh32_state - private xxh64 state, do not use members directly
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*/
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struct xxh64_state {
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uint64_t total_len;
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uint64_t v1;
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uint64_t v2;
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uint64_t v3;
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uint64_t v4;
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uint64_t mem64[4];
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uint32_t memsize;
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};
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/**
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* xxh32_reset() - reset the xxh32 state to start a new hashing operation
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*
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* @state: The xxh32 state to reset.
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* @seed: Initialize the hash state with this seed.
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*
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* Call this function on any xxh32_state to prepare for a new hashing operation.
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*/
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void xxh32_reset(struct xxh32_state *state, uint32_t seed);
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/**
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* xxh32_update() - hash the data given and update the xxh32 state
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*
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* @state: The xxh32 state to update.
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* @input: The data to hash.
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* @length: The length of the data to hash.
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*
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* After calling xxh32_reset() call xxh32_update() as many times as necessary.
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*
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* Return: Zero on success, otherwise an error code.
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*/
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int xxh32_update(struct xxh32_state *state, const void *input, size_t length);
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/**
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* xxh32_digest() - produce the current xxh32 hash
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*
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* @state: Produce the current xxh32 hash of this state.
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*
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* A hash value can be produced at any time. It is still possible to continue
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* inserting input into the hash state after a call to xxh32_digest(), and
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* generate new hashes later on, by calling xxh32_digest() again.
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*
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* Return: The xxh32 hash stored in the state.
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*/
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uint32_t xxh32_digest(const struct xxh32_state *state);
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/**
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* xxh64_reset() - reset the xxh64 state to start a new hashing operation
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*
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* @state: The xxh64 state to reset.
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* @seed: Initialize the hash state with this seed.
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*/
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void xxh64_reset(struct xxh64_state *state, uint64_t seed);
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/**
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* xxh64_update() - hash the data given and update the xxh64 state
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* @state: The xxh64 state to update.
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* @input: The data to hash.
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* @length: The length of the data to hash.
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*
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* After calling xxh64_reset() call xxh64_update() as many times as necessary.
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*
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* Return: Zero on success, otherwise an error code.
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*/
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int xxh64_update(struct xxh64_state *state, const void *input, size_t length);
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/**
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* xxh64_digest() - produce the current xxh64 hash
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*
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* @state: Produce the current xxh64 hash of this state.
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*
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* A hash value can be produced at any time. It is still possible to continue
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* inserting input into the hash state after a call to xxh64_digest(), and
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* generate new hashes later on, by calling xxh64_digest() again.
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*
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* Return: The xxh64 hash stored in the state.
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*/
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uint64_t xxh64_digest(const struct xxh64_state *state);
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/*-**************************
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* Utils
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***************************/
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/**
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* xxh32_copy_state() - copy the source state into the destination state
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*
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* @src: The source xxh32 state.
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* @dst: The destination xxh32 state.
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*/
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void xxh32_copy_state(struct xxh32_state *dst, const struct xxh32_state *src);
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/**
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* xxh64_copy_state() - copy the source state into the destination state
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*
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* @src: The source xxh64 state.
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* @dst: The destination xxh64 state.
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*/
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void xxh64_copy_state(struct xxh64_state *dst, const struct xxh64_state *src);
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#endif /* XXHASH_H */
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