File: murmurhashneutral2.c

package info (click to toggle)
ccache 3.1.10-1
  • links: PTS, VCS
  • area: main
  • in suites: jessie-kfreebsd
  • size: 1,696 kB
  • sloc: ansic: 14,640; sh: 1,689; makefile: 153; perl: 52
file content (50 lines) | stat: -rw-r--r-- 761 bytes parent folder | download | duplicates (3)
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
/*
 * MurmurHashNeutral2, by Austin Appleby. Released to the public domain. See
 * <http://murmurhash.googlepages.com>.
 */

#include "murmurhashneutral2.h"

unsigned int
murmurhashneutral2(const void *key, int len, unsigned int seed)
{
	const unsigned int m = 0x5bd1e995;
	const int r = 24;

	unsigned int h = seed ^ len;

	const unsigned char *data = (const unsigned char *)key;

	while (len >= 4) {
		unsigned int k;

		k  = data[0];
		k |= data[1] << 8;
		k |= data[2] << 16;
		k |= data[3] << 24;

		k *= m;
		k ^= k >> r;
		k *= m;

		h *= m;
		h ^= k;

		data += 4;
		len -= 4;
	}

	switch (len)
	{
	case 3: h ^= data[2] << 16;
	case 2: h ^= data[1] << 8;
	case 1: h ^= data[0];
	        h *= m;
	};

	h ^= h >> 13;
	h *= m;
	h ^= h >> 15;

	return h;
}