CFile::GetByID

static function GetByID($fileId, $realId = false)
{
	$fileId = (int)$fileId;

	if (CACHED_b_file === false)
	{
		$result = static::GetFromDb($fileId, $realId);
	}
	else
	{
		$files = static::GetFromCache($fileId, $realId);

		$result = new CDBResult;
		$result->InitFromArray(isset($files[$fileId]) ? [$files[$fileId]] : []);
	}
	return $result;
}