session problem

[dadamssg87]

I'm writing a shopping cart type of application for booking something. The cart will holds items as arrays in the session. The problem i'm i'm having is i can store 5 items in my cart and then once i try to store any more, it just won't. I'm not getting any php errors. I'm using the codeigniter framework, so it may be a codeigniter session storage problem. Hopefully you guys can look at it and can see if you spot any bad logic that i'm overlooking.

 

<?php
                 //generates random unique 32 character string
	$booking_hash = random_string('unique');

	//set items foreach night
	foreach($room['date_rate'] as $date => $rate)
	{
                        //produces random sha1 16 char length string
		$sha1 = random_string('sha1', 16);

		$session['items'][$sha1] = array(
					'code'       => $room['code'],
					'id'         => $room_id,
					'title'      => $room['title'],
					'date'       => date("n/j/Y",strtotime($date)),
					'price'      => $rate,
					'tax_one'    => money_format('%i',$room['tax_one'] * $rate),
					'tax_two'    => money_format('%i',$room['tax_two'] * $rate),
					'sales_tax'  => 0,
					'guests'     => $num_guests,
					'booking'    => $booking_hash,	
					'deposit'    => $deposit,									
		);
	}


	$existing_items = $this->session->userdata('items');

  	if(!empty($existing_items))
 	{
		$session['items'] = $existing_items + $session['items'];
    }

	$this->session->set_userdata($session);


?>

 

I just read some codeigniter session documentation. It says the cookie it's using can hold 4KB of data. I have no idea how much text 4KB can hold...