1#include "Platform.h"
2#include <stdio.h> // for NULL
3
4/* By Paul Hsieh (C) 2004, 2005.  Covered under the Paul Hsieh derivative
5   license. See:
6   http://www.azillionmonkeys.com/qed/weblicense.html for license details.
7
8   http://www.azillionmonkeys.com/qed/hash.html */
9
10/*
11#undef get16bits
12#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \
13  || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
14#define get16bits(d) (*((const uint16_t *) (d)))
15#endif
16
17#if !defined (get16bits)
18#define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\
19                       +(uint32_t)(((const uint8_t *)(d))[0]) )
20#endif
21*/
22
23FORCE_INLINE uint16_t get16bits ( const void * p )
24{
25  return *(const uint16_t*)p;
26}
27
28uint32_t SuperFastHash (const signed char * data, int len) {
29uint32_t hash = 0, tmp;
30int rem;
31
32  if (len <= 0 || data == NULL) return 0;
33
34  rem = len & 3;
35  len >>= 2;
36
37  /* Main loop */
38  for (;len > 0; len--) {
39    hash  += get16bits (data);
40    tmp    = (get16bits (data+2) << 11) ^ hash;
41    hash   = (hash << 16) ^ tmp;
42    data  += 2*sizeof (uint16_t);
43    hash  += hash >> 11;
44  }
45
46  /* Handle end cases */
47  switch (rem) {
48    case 3:	hash += get16bits (data);
49        hash ^= hash << 16;
50        hash ^= data[sizeof (uint16_t)] << 18;
51        hash += hash >> 11;
52        break;
53    case 2:	hash += get16bits (data);
54        hash ^= hash << 11;
55        hash += hash >> 17;
56        break;
57    case 1: hash += *data;
58        hash ^= hash << 10;
59        hash += hash >> 1;
60  }
61
62  /* Force "avalanching" of final 127 bits */
63  hash ^= hash << 3;
64  hash += hash >> 5;
65  hash ^= hash << 4;
66  hash += hash >> 17;
67  hash ^= hash << 25;
68  hash += hash >> 6;
69
70  return hash;
71}
72
73void SuperFastHash     ( const void * key, int len, uint32_t /*seed*/, void * out )
74{
75  *(uint32_t*)out = SuperFastHash((const signed char*)key,len);
76}
77