php – Customized cut back inventory code affecting date_modified – Find out how to bypass?

I’ve a inventory discount script that works completely. The one drawback is, when a purchase order is made and the inventory is decreased, the date_modified meta is up to date. This causes issues for different scripts I’ve, because the publish is not truly up to date – simply the inventory.

How can I obtain the identical consequence with this code, with out it truly updating the date_modified meta? (ie: solely replace date_modified when the product itself is manually up to date).

// ---------------------------------------------------------------------------------------- //
// --------------------------  REDUCE WEIGHT BASED ON WEIGHT FIELD  ----------------------- //
// ---------------------------------------------------------------------------------------- //

// cut back inventory based mostly on 'pa_weight' attribute
add_filter( 'woocommerce_order_item_quantity', 'filter_order_item_quantity', 10, 3 ); 
operate filter_order_item_quantity( $amount, $order, $merchandise )  
{
    $product   = $item->get_product();
    $term_name = $product->get_attribute('pa_weight');

    // 'pa_weight' - preserve solely the numbers
    $amount = preg_replace('/[^0-9.]+/', '', $term_name);

    // new amount
    if( is_numeric ( $amount ) && $amount != 0 )
        $amount *= $amount;

    return $amount;
}


/**
 * Order change inventory discount repair.
 * 
 * @param $forestall
 * @param $merchandise
 * @param $item_quantity
 * @return bool|blended
 */
operate custom_stock_reduction_order_change( $forestall, $merchandise, $item_quantity ) {
    $stock_reduced   = wc_stock_amount( $item->get_meta( '_reduced_stock', true ) );
    $stock_reduction = filter_order_item_quantity( $item->get_quantity(), null, $merchandise );

    if ( $stock_reduction == $stock_reduced ) {
        $forestall = true;
    }

    return $forestall;
}
add_filter( 'woocommerce_prevent_adjust_line_item_product_stock', 'custom_stock_reduction_order_change', 10, 3 );