protected function createIdentifierForFile($pathAndFilename, $prefix)
{
$templateModifiedTimestamp = 0;
$isStandardInput = $pathAndFilename === 'php://stdin';
$isFile = is_file($pathAndFilename);
if ($isStandardInput === false && $isFile === false) {
throw new InvalidTemplateResourceException(sprintf('The fluid file "%s" was not found.', $pathAndFilename), 1475831187);
}
if ($isStandardInput === false) {
$templateModifiedTimestamp = filemtime($pathAndFilename);
}
return sprintf('%s_%s', $prefix, sha1($pathAndFilename . '|' . $templateModifiedTimestamp));
}