Adding in patch for DEAD server completion.
[awesomized/libmemcached] / libhashkit / fnv_32.cc
1 /* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
2 *
3 * HashKit library
4 *
5 * Copyright (C) 2011 Data Differential, http://datadifferential.com/
6 * Copyright (C) 2009 Brian Aker All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are
10 * met:
11 *
12 * * Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * * Redistributions in binary form must reproduce the above
16 * copyright notice, this list of conditions and the following disclaimer
17 * in the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * * The names of its contributors may not be used to endorse or
21 * promote products derived from this software without specific prior
22 * written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
30 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
34 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 *
36 */
37
38
39 #include <libhashkit/common.h>
40
41 /* FNV hash'es lifted from Dustin Sallings work */
42 static uint32_t FNV_32_INIT= 2166136261UL;
43 static uint32_t FNV_32_PRIME= 16777619;
44
45 uint32_t hashkit_fnv1_32(const char *key, size_t key_length, void *context)
46 {
47 uint32_t hash= FNV_32_INIT;
48 (void)context;
49
50 for (size_t x= 0; x < key_length; x++)
51 {
52 uint32_t val= (uint32_t)key[x];
53 hash *= FNV_32_PRIME;
54 hash ^= val;
55 }
56
57 return hash;
58 }
59
60 uint32_t hashkit_fnv1a_32(const char *key, size_t key_length, void *context)
61 {
62 uint32_t hash= FNV_32_INIT;
63 (void)context;
64
65 for (size_t x= 0; x < key_length; x++)
66 {
67 uint32_t val= (uint32_t)key[x];
68 hash ^= val;
69 hash *= FNV_32_PRIME;
70 }
71
72 return hash;
73 }