-/* 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
+ +--------------------------------------------------------------------+
+ | libmemcached-awesome - C/C++ Client Library for memcached |
+ +--------------------------------------------------------------------+
+ | Redistribution and use in source and binary forms, with or without |
+ | modification, are permitted under the terms of the BSD license. |
+ | You should have received a copy of the license in a bundled file |
+ | named LICENSE; in case you did not receive a copy you can review |
+ | the terms online at: https://opensource.org/licenses/BSD-3-Clause |
+ +--------------------------------------------------------------------+
+ | Copyright (c) 2006-2014 Brian Aker https://datadifferential.com/ |
+ | Copyright (c) 2020-2021 Michael Wallner https://awesome.co/ |
+ +--------------------------------------------------------------------+
*/
#include "libhashkit/common.h"
#ifdef HAVE_MURMUR_HASH
-#include <cstring>
+# ifdef BYTESWAP_HEADER
+# include BYTESWAP_HEADER
+# endif
+
+# include <cstring>
-uint32_t hashkit_murmur(const char *key, size_t length, void *context)
-{
+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;
-
+ 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;
+ 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;
+ const unsigned char *data = (const unsigned char *) key;
+ (void) context;
- while(length >= 4)
- {
+ while (length >= 4) {
uint32_t k;
-#if WORDS_BIGENDIAN
- k = (data[0]<<24)
- | (data[1]<<16)
- | (data[2]<<8)
- | (data[3])
- ;
-#else
memcpy(&k, data, sizeof(k));
-#endif
+# if WORDS_BIGENDIAN
+ k = BYTESWAP_32(k);
+# endif
k *= m;
k ^= k >> r;
}
// Handle the last few bytes of the input array
-
- switch(length)
- {
-#if WORDS_BIGENDIAN
- case 3: h ^= ((uint32_t)data[2]) << 8; /* fall through */
- case 2: h ^= ((uint32_t)data[1]) << 16; /* fall through */
- case 1: h ^= ((uint32_t)data[0]) << 24;
-#else
- 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];
-#endif
- h *= m;
- default: break;
- };
+ if (length) {
+ uint32_t k = 0;
+ memcpy(&k, data, length);
+# if WORDS_BIGENDIAN
+ k = BYTESWAP_32(k);
+# endif
+ h ^= k;
+ h *= m;
+ }
/*
Do a few final mixes of the hash to ensure the last few bytes are
}
#else
-uint32_t hashkit_murmur(const char *, size_t , void *)
-{
+uint32_t hashkit_murmur(const char *, size_t, void *) {
return 0;
}
#endif