should::makeDeltaSets

static function makeDeltaSets(array $items, array $currentItemsData)
{
	$toAdd = array();
	$toUpdate = array();
	$toDelete = array();

	foreach($items as $id => $item)
	{
		if(isset($currentItemsData[$id]))
		{
			if(static::detectItemChanged($currentItemsData[$id], $items[$id]))
			{
				$toUpdate[$id] = true;
			}
		}
		else
		{
			$toAdd[$id] = true;
		}
	}

	foreach($currentItemsData as $id => $item)
	{
		if(!isset($items[$id]))
		{
			$toDelete[$id] = true;
		}
	}

	return array(array_keys($toAdd), array_keys($toUpdate), array_keys($toDelete));
}