Execute imap_close not working

Question

I have page with customers and with ajax im loading info on whether they send us email or not.

Code looks like this:

$hostname = '{imap.gmail.com:993/imap/ssl}INBOX';
$username = 'email';
$password = 'password';

$this->session->data['imap_inbox'] = $inbox = imap_open($hostname,$username,$password) or die('Cannot connect to Gmail: ' . imap_last_error());

 foreach($customers as $customer){
     $emails = imap_search($inbox, 'FROM ' . $email);
     // Processing info
 }

But there are roughly 20-30 customers on one page, so the proccess takes sometimes about 10-20 seconds to show and I was unable to optimize the process.

But when client tries to reload a page, it is still waiting before imap_search finishes, so when reloading it could take 20 seconds before the page is actually reloaded.

I have tried to abort the ajax with beforeunload function and close the imap but this is not working.

My code:

Ajax:

    $(window).bind('beforeunload',function(){
    imap_email.abort(); // the ajax is succesfully aborted(as showed in console), yet the page still takes considerable time to reload

    $.ajax({
        type: 'GET',
        url: 'getimapmails&kill=1',
        async:false
    }); // ajax call to the same function to call imap_close 

});

PHP:

if($this->request->get['kill'] == '1'){
            imap_close($this->session->data['imap_inbox']);
            unset($this->session->data['imap_inbox']);
            $kill == 1;
            exit;
        }

But even though the ajax is aborted and imap_close is called on variable holding imap_open, it still takes 10-20 seconds for page to reload, so I'm assuming the imap was not closed.

How do I close the imap so the page can reload immediately?

Answer 1

I would recommend killing it by creating a file that causes a break:

$hostname = '{imap.gmail.com:993/imap/ssl}INBOX';
$username = 'email';
$password = 'password';

$this->session->data['imap_inbox'] = $inbox = imap_open($hostname,$username,$password) or die('Cannot connect to Gmail: ' . imap_last_error());

 foreach($customers as $customer){
      clearstatcache(); //Can't use the cached result.
     if(file_exists('/tmp/kill_imap.'.$this->session->id)) break;  //making the assumption that /tmp and session->id are set, but the idea is a temporary folder and a unique identifier to that session.
     $emails = imap_search($inbox, 'FROM ' . $email);
     // Processing info
 }
 if(file_exists('/tmp/kill_imap.'.$this->session->id)) unlink('/tmp/kill_imap.'.$this->session->id);

Then on your exit ajax, just call to a php script that simply creates that file. and it will break your loop and remove the file.

Answer 2

If I understood correctly, the time-consuming code lies within the foreach() loop.

Now, even if you make a second request to kill the IMAP session, that foreach() loop will continue until either it finishes or PHP kills it if (and when) execution time exceeds your max_execution_time setting.

In any case, you need something within your foreach() loop that will check on each round if a condition to abort has been met, so as to switfly terminate the current request and allow the client to make new one.

I suggest you look at the PHP function connection_aborted(), that you could use to detect once the client aborts the current request, and more generally you could read on the topic of connection handling to get a better sense of how connections and requests are handled in PHP.