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https://github.com/trapexit/mergerfs.git
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0371b047f9
wyhash has very good performance for small keys (our usecase) and works on platforms with alignment concerns. A user had an issue where fasthash64 lead to misaligned reads and signal exceptions. wyhash does not have such issues and is faster.
76 lines
1.5 KiB
C++
76 lines
1.5 KiB
C++
/*
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ISC License
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Copyright (c) 2018, Antonio SJ Musumeci <trapexit@spawn.link>
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Permission to use, copy, modify, and/or distribute this software for any
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purpose with or without fee is hereby granted, provided that the above
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copyright notice and this permission notice appear in all copies.
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THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#pragma once
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#include "khash.h"
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#include "wyhash.h"
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KHASH_SET_INIT_INT64(hashset);
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class HashSet
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{
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public:
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HashSet()
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{
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_set = kh_init(hashset);
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}
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~HashSet()
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{
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kh_destroy(hashset,_set);
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}
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inline
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int
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put(const char *str_,
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const uint64_t len_)
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{
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int rv;
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uint64_t h;
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khint_t key;
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h = wyhash(str_,len_,0x7472617065786974,_wyp);
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key = kh_put(hashset,_set,h,&rv);
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if(rv == 0)
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return 0;
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kh_key(_set,key) = h;
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return rv;
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}
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inline
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int
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put(const char *str_)
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{
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return put(str_,strlen(str_));
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}
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inline
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int
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size(void)
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{
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return kh_size(_set);
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}
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private:
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khash_t(hashset) *_set;
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};
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