uint32_t murmur3_32(const char *key, uint32_t len, uint32_t seed) { static const uint32_t c1 = 0xcc9e2d51; static const uint32_t c2 = 0x1b873593; static const uint32_t r1 = 15; static const uint32_t r2 = 13; static const uint32_t m = 5; static 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))) * 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;
}