aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/libraries/eina/src/include/eina_inline_hash.x
blob: be20e8fa5d902c4a579d7d01bb8f6e150240bd9a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
/* EINA - EFL data type library
 * Copyright (C) 2002-2008 Carsten Haitzler
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library;
 * if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef EINA_INLINE_HASH_X_
#define EINA_INLINE_HASH_X_

/*
  djb2 hash algorithm was first reported by dan bernstein, and was the old
  default hash function for evas.
 */
static inline int
eina_hash_djb2(const char *key, int len)
{
   unsigned int hash_num = 5381;
   const unsigned char *ptr;

   if (!key) return 0;
   for (ptr = (unsigned char *)key; len; ptr++, len--)
     hash_num = ((hash_num << 5) + hash_num) ^ *ptr; /* hash * 33 ^ c */

   return (int)hash_num;
}

static inline int
eina_hash_djb2_len(const char *key, int *plen)
{
   unsigned int hash_num = 5381;
   int len = 0;
   const unsigned char *ptr;

   if (!key) return 0;

   for (ptr = (unsigned char *)key; *ptr; ptr++, len++)
     hash_num = ((hash_num << 5) + hash_num) ^ *ptr; /* hash * 33 ^ c */

   *plen = len + 1;

   return (int)hash_num;
}

static inline int
eina_hash_int32(const unsigned int *pkey, int len)
{
   unsigned int key = *pkey;

   (void) len;

   key  = ~key + (key << 15);
   key ^= key >> 12;
   key += key << 2;
   key ^= key >> 4;
   key *= 2057;
   key ^= key >> 16;
   return key;
}

static inline int
eina_hash_int64(const unsigned long int *pkey, int len)
{
   unsigned long int key = *pkey;

   (void) len;

   key  = ~key + (key << 18);
   key ^= key >> 31;
   key *= 21;
   key ^= key >> 11;
   key += key << 6;
   key ^= key >> 22;
   return (int) key;
}

static inline unsigned int _rotl32(unsigned int x, char r)
{
   return (x << r) | (x >> (32 - r));
}

static inline unsigned int _fmix32(unsigned int h)
{
   h ^= h >> 16;
   h *= 0x85ebca6b;
   h ^= h >> 13;
   h *= 0xc2b2ae35;
   h ^= h >> 16;

   return h;
}

static inline int
eina_hash_murmur3(const char *key, int len)
{
   const unsigned char * data = (const unsigned char*)key;
   const int nblocks = len / 4;
   unsigned int h1 = 0, k1;
   unsigned int c1 = 0xcc9e2d51;
   unsigned int c2 = 0x1b873593;
   const unsigned int * blocks = (const unsigned int *)(data + nblocks*4);
   int i;
   const unsigned char *tail;

   for(i = -nblocks; i; i++)
     {
        k1 = blocks[i];

        k1 *= c1;
        k1 = _rotl32(k1, 15);
        k1 *= c2;

        h1 ^= k1;
        h1 = _rotl32(h1, 13);
        h1 = h1*5+0xe6546b64;
     }

   tail = (const unsigned char*)(data + nblocks*4);

   k1 = 0;

   switch(len & 3)
     {
      case 3:
         k1 ^= tail[2] << 16;
      case 2:
         k1 ^= tail[1] << 8;
      case 1:
         k1 ^= tail[0];
         k1 *= c1;
         k1 = _rotl32(k1, 16);
         k1 *= c2;
         h1 ^= k1;
     }

   h1 ^= len;

   return _fmix32(h1);
}
#endif