53 lines
1.8 KiB
C++
53 lines
1.8 KiB
C++
/*
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* This file is part of libgim.
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*
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* libgim is free software: you can redistribute it and/or modify it under the
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* terms of the GNU General Public License as published by the Free Software
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* Foundation, either version 3 of the License, or (at your option) any later
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* version.
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*
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* libgim is distributed in the hope that it will be useful, but WITHOUT ANY
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* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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* details.
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*
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* You should have received a copy of the GNU General Public License
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* along with libgim. If not, see <http://www.gnu.org/licenses/>.
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*
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* Copyright 2010 Danny Robson <danny@nerdcruft.net>
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*/
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#ifndef __UTIL_HASH_HPP
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#define __UTIL_HASH_HPP
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#include <cstdint>
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#include <cstdlib>
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// All hashes are unsuitable for cryptographic operations nnless noted.
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namespace util {
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// Fast integer mixing operations by Thomas Wang.
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uint32_t wang32 (uint32_t key);
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uint64_t wang64 (uint64_t key);
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// Fast and general hashing using FNV-1a
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uint32_t fnv1a32 (const void *, size_t);
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uint64_t fnv1a64 (const void *, size_t);
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// General hashes for when you really just don't care about implementation
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inline uint32_t hash (uint32_t key) { return wang32 (key); }
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inline int32_t hash ( int32_t key) { return (int32_t) hash ((uint32_t)key); }
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inline uint64_t hash (uint64_t key) { return wang64 (key); }
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inline int64_t hash ( int64_t key) { return (int64_t) hash ((uint64_t)key); }
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inline uintptr_t hash (const void *key) {
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return sizeof (uintptr_t) == 32 ? wang32 (reinterpret_cast<uintptr_t> (key)) :
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wang64 (reinterpret_cast<uintptr_t> (key));
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}
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}
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#endif
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