How to change the number of goods after the exchange of 1s Bitrix?

Question

1C-Bitrix

After the exchange, I need to change the available quantity of goods, I do this

AddEventHandler('catalog', 'OnCompleteCatalogImport1C', 'quantityCatalogImportStep');

function quantityCatalogImportStep() 
{
      $addProps = CIBlockElement::GetList (
  Array("QUANTITY" => "ASC"),
  Array("IBLOCK_ID" => 18),
false,
    false,
      Array(
      'ID', 'QUANTITY', 'NAME', 'PROPERTY_MIN_UPAKOVKA'
      )
);
while($ar_fields = $addProps->GetNext())
{

   $kolvo = $ar_fields['QUANTITY'];
   $min_upakovka = $ar_fields['PROPERTY_MIN_UPAKOVKA_VALUE'];
  $new_kolvo = (int)($kolvo / $min_upakovka);
      if ($ar_fields['QUANTITY'] > 0 && $ar_fields['PROPERTY_MIN_UPAKOVKA_VALUE'] > 0) {

  Cmodule::IncludeModule('catalog');
  $PRODUCT_ID = $ar_fields['ID'];
  $arFields = array(
    'QUANTITY' => $new_kolvo
  );
  CCatalogProduct::Update($PRODUCT_ID, $arFields);
    }


}
}

but it changes after the last exchange, and the quantities appear early i.e. the amount that I don't need hangs while the import is in progress (half an hour / hour) for which event or how to make it change immediately?
set it to OnSuccessCatalogImport1C, but then it changes the number with each package, which is 12 times

Answer 1

Have you tried changing the quantity during the exchange?
An example handler can be viewed here .
And a couple of notes:

1. don't use GetNext() if Fetch() is enough
   
2. it would be better to first check that the packing size is non-zero, and then divide by it