murmurhash3.c File Reference

#include <stdint.h>
#include <stdlib.h>
#include <string.h>

Go to the source code of this file.

Functions
uint32_t	ck_murmurhash3 (const char *key, uint32_t len, uint32_t seed)
uint32_t	ck_murmurhash3_32 (const void *key, size_t len, uint32_t seed)
static uint32_t	ck_murmurhash3_str (const char *key, uint32_t seed)

Function Documentation

ck_murmurhash3()

uint32_t ck_murmurhash3	(	const char *	key,
		uint32_t	len,
		uint32_t	seed
	)

MurmurHash3-32bit hash function (original HPC_Embeddings version).

Parameters

key	Data to hash
len	Length in bytes
seed	Seed value

Returns

32-bit hash value

Definition at line 11 of file murmurhash3.c.

                                                                      {
    const uint32_t c1 = 0xcc9e2d51;
    const uint32_t c2 = 0x1b873593;
    const uint32_t r1 = 15;
    const uint32_t r2 = 13;
    const uint32_t m = 5;
    const uint32_t n = 0xe6546b64;
 
    uint32_t hash = seed;
 
    const int nblocks = len / 4;
    const uint32_t *blocks = (const uint32_t *)(key);
    int i;
    for (i = 0; i < nblocks; i++) {
        uint32_t k = blocks[i];
 
        k *= c1;
        k = (k << r1) | (k >> (32 - r1));
        k *= c2;
 
        hash ^= k;
        hash = (hash << r2) | (hash >> (32 - r2));
        hash = hash * m + n;
    }
 
    const uint8_t *tail = (const uint8_t *)(key + nblocks * 4);
    uint32_t 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 = (k1 << r1) | (k1 >> (32 - r1));
            k1 *= c2;
            hash ^= k1;
    }
 
    hash ^= len;
    hash ^= hash >> 16;
    hash *= 0x85ebca6b;
    hash ^= hash >> 13;
    hash *= 0xc2b2ae35;
    hash ^= hash >> 16;
 
    return hash;
}

Referenced by ck_murmurhash3_32(), ck_murmurhash3_str(), ck_murmurhash3_strn(), and ck_tokenizer_hash().

ck_murmurhash3_32()

uint32_t ck_murmurhash3_32	(	const void *	key,
		size_t	len,
		uint32_t	seed
	)

MurmurHash3-32bit hash function (alternative name).

Parameters

key	Data to hash
len	Length in bytes
seed	Optional seed value (use 0 for default)

Returns

32-bit hash value

Definition at line 68 of file murmurhash3.c.

                                                                       {
    return ck_murmurhash3((const char *)key, (uint32_t)len, seed);
}

References ck_murmurhash3().

Referenced by ck_murmurhash3_str().

ck_murmurhash3_str()

static uint32_t ck_murmurhash3_str ( const char *  key, uint32_t  seed  )

inlinestatic

Definition at line 63 of file murmurhash3.c.

                                                                          {
    return ck_murmurhash3(key, (uint32_t)strlen(key), seed);
}

References ck_murmurhash3().