/**
* Ping a mailbox. This detects only if any new messages have arrived in
* the specified mailbox.
*
* @param Horde_ActiveSync_Folder_Imap $folder The folder object.
*
* @return boolean True if changes were detected, otherwise false.
* @throws Horde_ActiveSync_Exception, Horde_ActiveSync_Exception_FolderGone
*/
public function ping(Horde_ActiveSync_Folder_Imap $folder)
{
$mbox = new Horde_Imap_Client_Mailbox($folder->serverid());
// Note: non-CONDSTORE servers will return a highestmodseq of 0
$status_flags = Horde_Imap_Client::STATUS_HIGHESTMODSEQ | Horde_Imap_Client::STATUS_UIDNEXT_FORCE | Horde_Imap_Client::STATUS_MESSAGES | Horde_Imap_Client::STATUS_FORCE_REFRESH;
// Get IMAP status.
try {
$status = $this->_getImapOb()->status($mbox, $status_flags);
} catch (Horde_Imap_Client_Exception $e) {
// See if the folder disappeared.
if (!$this->_mailboxExists($mbox->utf8)) {
throw new Horde_ActiveSync_Exception_FolderGone();
}
throw new Horde_ActiveSync_Exception($e);
}
// If we have per mailbox MODSEQ then we can pick up flag changes too.
$modseq = $status[Horde_ActiveSync_Folder_Imap::HIGHESTMODSEQ];
if ($modseq && $folder->modseq() > 0 && $folder->modseq() < $modseq) {
return true;
}
// Increase in UIDNEXT is always a positive PING.
if ($folder->uidnext() < $status['uidnext']) {
return true;
}
// If the message count changes, something certainly changed.
if ($folder->total_messages() != $status['messages']) {
return true;
}
// Otherwise, no PING detectable changes present.
return false;
}
