X-Git-Url: https://git.m6w6.name/?a=blobdiff_plain;ds=inline;f=libhashkit%2Fmurmur.cc;h=5ad796b19bb647437cb9886d8be0c866b525980d;hb=HEAD;hp=f3e8fe6ac7eebcca2d92d72e69d19e249aed2934;hpb=cefa03b14574d23cdd2f9db5ff28f210e697042c;p=awesomized%2Flibmemcached diff --git a/libhashkit/murmur.cc b/libhashkit/murmur.cc deleted file mode 100644 index f3e8fe6a..00000000 --- a/libhashkit/murmur.cc +++ /dev/null @@ -1,126 +0,0 @@ -/* vim:expandtab:shiftwidth=2:tabstop=2:smarttab: - * - * HashKit library - * - * Copyright (C) 2011-2012 Data Differential, http://datadifferential.com/ - * Copyright (C) 2006-2009 Brian Aker All rights reserved. - * - * Redistribution and use 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. - * - * * The names of its contributors may not be used to endorse or - * promote products derived from this software without specific prior - * written permission. - * - * 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. - * - */ - -/* - "Murmur" hash provided by Austin, tanjent@gmail.com - http://murmurhash.googlepages.com/ - - Note - This code makes a few assumptions about how your machine behaves - - - 1. We can read a 4-byte value from any address without crashing - 2. sizeof(int) == 4 - - And it has a few limitations - - 1. It will not work incrementally. - 2. It will not produce the same results on little-endian and big-endian - machines. - - Updated to murmur2 hash - BP -*/ - -#include - -#ifdef HAVE_MURMUR_HASH - -#include - -uint32_t hashkit_murmur(const char *key, size_t length, void *context) -{ - /* - 'm' and 'r' are mixing constants generated offline. They're not - really 'magic', they just happen to work well. - */ - - const unsigned int m= 0x5bd1e995; - const uint32_t seed= (0xdeadbeef * (uint32_t)length); - const int r= 24; - - - // Initialize the hash to a 'random' value - - uint32_t h= seed ^ (uint32_t)length; - - // Mix 4 bytes at a time into the hash - - const unsigned char * data= (const unsigned char *)key; - (void)context; - - while(length >= 4) - { - unsigned int k; - memcpy(&k, data, sizeof(unsigned int)); - - k *= m; - k ^= k >> r; - k *= m; - - h *= m; - h ^= k; - - data += 4; - length -= 4; - } - - // Handle the last few bytes of the input array - - switch(length) - { - case 3: h ^= ((uint32_t)data[2]) << 16; /* fall through */ - case 2: h ^= ((uint32_t)data[1]) << 8; /* fall through */ - case 1: h ^= data[0]; - h *= m; - default: break; - }; - - /* - Do a few final mixes of the hash to ensure the last few bytes are - well-incorporated. - */ - - h ^= h >> 13; - h *= m; - h ^= h >> 15; - - return h; -} - -#else -uint32_t hashkit_murmur(const char *, size_t , void *) -{ - return 0; -} -#endif