#include <cstring> // std::memcpy

#include "hash.h"

// 128 bit hash via djbx33ax4 (Daniel Bernstein Times 33 with Addition interleaved 4x for 128 bits)

static void Hash128(const uint8_t *buffer, size_t size, uint8_t *out)

{

const uint8_t *const end = (const uint8_t *const )buffer + size;

uint32_t state[] = { 5381, 5381, 5381, 5381 };

size_t s = 0;

for (const uint8_t *p = buffer; p < end; p++)

{

state[s] = state[s] * 33 + *p;

s = (s+1) & 0x03;

}

std::memcpy(out, state, sizeof state);

}

std::string Hash128(const uint8_t *buffer, size_t size)

{

std::string result;

uint8_t output[16];

Hash128(buffer, size, output);

static const char *k_hex = "0123456789ABCDEF";

for (size_t i = 0; i < sizeof output; ++i)

{

result += k_hex[(output[i] >> 4) & 0x0F];

result += k_hex[output[i] & 0x0F];

}

return result;

}