Magento Iterator Vs Foreach Loop How to return an array?

Question

I've encountered a problem where my foreach loop is causing a 504 Gateway timeout error so I did some research and found that for large collections it is better to use the core/resource_iterator and the walk() function.

This has definitely improved performance but I have lost the ability to return the array the I need from when I call my custom function.

$this->getAllDataFromTable()

Here is what I mean: This function will get all the data from the table and return the $array variable which I can do stuff with - but is very expensive and times out with a 504 error.

public static function getAllDataFromTable()
{
    $model = Mage::getModel('custom/table');
    $collection = $model->getCollection();
    $array = array();
    foreach ($collection as $item) {
        $array[] = $item->getData();
    }
    return $array;
}

Using the iterator: The iterator is more efficient but I can only do stuff with the last row, I would like a similar $array returned so I can do stuff with it.

/**
 * Mage_Core_Model_Resource_Iterator
 */
public function getAllDataFromTable()
{
    $ordersCollection = Mage::getModel('custom/table')->getCollection();
    Mage::getSingleton('core/resource_iterator')->walk($ordersCollection->getSelect(),
        array(array($this, 'orderCallback'))
    );
}

public function orderCallback($args)
{
  return $args['row'];
}

Answer 1

Well you can simply assign a variable to the class and do something like this:

private $data = [];

public function getAllDataFromTable()
{
    $ordersCollection = Mage::getModel('custom/table')->getCollection();
    Mage::getSingleton('core/resource_iterator')->walk($ordersCollection->getSelect(),
        array(array($this, 'orderCallback'))
    );
    return $this->data;
}

public function orderCallback($args)
{
    $this->data[] = $args['row'];
}

Also, depending what you want to do with it (when you say "return the $array variable which I can do stuff with") you can add that logic directly in the callback method and that'll save you one array to fill and return.