54 lines
1.9 KiB
C
54 lines
1.9 KiB
C
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/*-
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* Copyright 2012 Matthew Endsley
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* All rights reserved
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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 providing that the following conditions
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* are met:
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* 1. 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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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef TINYSTL_STRINGHASH_H
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#define TINYSTL_STRINGHASH_H
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#include "stddef.h"
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namespace tinystl {
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static inline size_t hash_string(const char* str, size_t len) {
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// Implementation of sdbm a public domain string hash from Ozan Yigit
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// see: http://www.eecs.harvard.edu/margo/papers/usenix91/paper.ps
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size_t hash = 0;
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typedef const char* pointer;
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for (pointer it = str, end = str + len; it != end; ++it)
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hash = *it + (hash << 6) + (hash << 16) - hash;
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return hash;
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}
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template<typename T>
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inline size_t hash(const T& value) {
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const size_t asint = (size_t)value;
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return hash_string((const char*)&asint, sizeof(asint));
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}
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}
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#endif
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