/**
* Get an array of the pre-computed parity of all 8-bit words
*
* @return array
*/
function getParityOfWords()
{
static $cachedParities = [];
if (empty($cachedParities)) {
if (!file_exists('computed_parities.txt')) {
$bitwiseHelper = new BitwiseHelper();
$cachedParities = $bitwiseHelper->computeParityOfWords(0b11111111);
$fp = fopen('computed_parities.txt', 'w');
fwrite($fp, serialize($cachedParities));
fclose($fp);
} else {
$cachedParities = unserialize(file_get_contents('computed_parities.txt'));
}
}
return $cachedParities;
}
