| /* |
| Open Asset Import Library (assimp) |
| ---------------------------------------------------------------------- |
| |
| Copyright (c) 2006-2017, assimp team |
| |
| All rights reserved. |
| |
| Redistribution and use of this software 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. |
| |
| * Neither the name of the assimp team, nor the names of its |
| contributors may be used to endorse or promote products |
| derived from this software without specific prior |
| written permission of the assimp team. |
| |
| 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. |
| |
| ---------------------------------------------------------------------- |
| */ |
| |
| #ifndef AI_HASH_H_INCLUDED |
| #define AI_HASH_H_INCLUDED |
| |
| #include <stdint.h> |
| #include <string.h> |
| |
| // ------------------------------------------------------------------------------------------------ |
| // Hashing function taken from |
| // http://www.azillionmonkeys.com/qed/hash.html |
| // (incremental version) |
| // |
| // This code is Copyright 2004-2008 by Paul Hsieh. It is used here in the belief that |
| // Assimp's license is considered compatible with Pauls's derivative license as specified |
| // on his web page. |
| // |
| // (stdint.h should have been been included here) |
| // ------------------------------------------------------------------------------------------------ |
| #undef get16bits |
| #if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \ |
| || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__) |
| #define get16bits(d) (*((const uint16_t *) (d))) |
| #endif |
| |
| #if !defined (get16bits) |
| #define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\ |
| +(uint32_t)(((const uint8_t *)(d))[0]) ) |
| #endif |
| |
| // ------------------------------------------------------------------------------------------------ |
| inline uint32_t SuperFastHash (const char * data, uint32_t len = 0, uint32_t hash = 0) { |
| uint32_t tmp; |
| int rem; |
| |
| if (!data) return 0; |
| if (!len)len = (uint32_t)::strlen(data); |
| |
| rem = len & 3; |
| len >>= 2; |
| |
| /* Main loop */ |
| for (;len > 0; len--) { |
| hash += get16bits (data); |
| tmp = (get16bits (data+2) << 11) ^ hash; |
| hash = (hash << 16) ^ tmp; |
| data += 2*sizeof (uint16_t); |
| hash += hash >> 11; |
| } |
| |
| /* Handle end cases */ |
| switch (rem) { |
| case 3: hash += get16bits (data); |
| hash ^= hash << 16; |
| hash ^= data[sizeof (uint16_t)] << 18; |
| hash += hash >> 11; |
| break; |
| case 2: hash += get16bits (data); |
| hash ^= hash << 11; |
| hash += hash >> 17; |
| break; |
| case 1: hash += *data; |
| hash ^= hash << 10; |
| hash += hash >> 1; |
| } |
| |
| /* Force "avalanching" of final 127 bits */ |
| hash ^= hash << 3; |
| hash += hash >> 5; |
| hash ^= hash << 4; |
| hash += hash >> 17; |
| hash ^= hash << 25; |
| hash += hash >> 6; |
| |
| return hash; |
| } |
| |
| #endif // !! AI_HASH_H_INCLUDED |