/**
* Get an array of the pre-computed reverse of all 8-bit words
*
* @return array
*/
function getReverseOf8BitWords()
{
static $cachedReverses = [];
if (empty($cachedReverses)) {
if (!file_exists('computed_reverses.txt')) {
$bitwiseHelper = new BitwiseHelper();
$cachedReverses = $bitwiseHelper->computeReverseOf8BitWords(0b11111111);
$fp = fopen('computed_reverses.txt', 'w');
fwrite($fp, serialize($cachedReverses));
fclose($fp);
} else {
$cachedReverses = unserialize(file_get_contents('computed_reverses.txt'));
}
}
return $cachedReverses;
}
