XXH_PUBLIC_API unsigned long long XXH64(const void* input, size_t len, unsigned long long seed)
{
#if 0
/* Simple version, good for code maintenance, but unfortunately slow for small inputs */
XXH64_state_t state;
XXH64_reset(&state, seed);
XXH64_update(&state, input, len);
return XXH64_digest(&state);
#else
XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
if (XXH_FORCE_ALIGN_CHECK) {
if ((((size_t)input) & 7) == 0) { /* Input is aligned, let's leverage the speed advantage */
if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);
else
return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
}
}
if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);
else
return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
#endif
}
这是XXH64哈希函数(http://www.opensource.org/licenses/bsd-license.php)
当我在释放模式和调试模式下运行代码时
char buf[65];
unsigned int hash2 = 0;
sprintf(buf, "%I64u", (unsigned long long)_message);
unsigned long long hash = XXH64(buf,sizeof(buf)-1,0);
hash = hash % _n;
hash2 = (unsigned int)hash;
printf("message's hash value : %u \n", hash2);
每种模式都有不同的哈希值和相同的代码。