Add some doc comments to QueueHandler

This commit is contained in:
Brion Vibber 2009-10-22 09:59:27 -07:00
parent 4e639b8769
commit c6d1039901

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@ -27,6 +27,22 @@ define('CLAIM_TIMEOUT', 1200);
define('QUEUE_HANDLER_MISS_IDLE', 10);
define('QUEUE_HANDLER_HIT_IDLE', 0);
/**
* Base class for queue handlers.
*
* As extensions of the Daemon class, each queue handler has the ability
* to launch itself in the background, at which point it'll pass control
* to the configured QueueManager class to poll for updates.
*
* Subclasses must override at least the following methods:
* - transport
* - start
* - finish
* - handle_notice
*
* Some subclasses will also want to override the idle handler:
* - idle
*/
class QueueHandler extends Daemon
{
@ -39,6 +55,14 @@ class QueueHandler extends Daemon
}
}
/**
* How many seconds a polling-based queue manager should wait between
* checks for new items to handle.
*
* Defaults to 60 seconds; override to speed up or slow down.
*
* @return int timeout in seconds
*/
function timeout()
{
return 60;
@ -54,24 +78,69 @@ class QueueHandler extends Daemon
return strtolower($this->class_name().'.'.$this->get_id());
}
/**
* Return transport keyword which identifies items this queue handler
* services; must be defined for all subclasses.
*
* Must be 8 characters or less to fit in the queue_item database.
* ex "email", "jabber", "sms", "irc", ...
*
* @return string
*/
function transport()
{
return null;
}
/**
* Initialization, run when the queue handler starts.
* If this function indicates failure, the handler run will be aborted.
*
* @fixme run() will abort if this doesn't return true,
* but some subclasses don't bother.
* @return boolean true on success, false on failure
*/
function start()
{
}
/**
* Cleanup, run when the queue handler ends.
* If this function indicates failure, a warning will be logged.
*
* @fixme run() will throw warnings if this doesn't return true,
* but many subclasses don't bother.
* @return boolean true on success, false on failure
*/
function finish()
{
}
/**
* Here's the meat of your queue handler -- you're handed a Notice
* object, which you may do as you will with.
*
* If this function indicates failure, a warning will be logged
* and the item is placed back in the queue to be re-run.
*
* @param Notice $notice
* @return boolean true on success, false on failure
*/
function handle_notice($notice)
{
return true;
}
/**
* Setup and start of run loop for this queue handler as a daemon.
* Most of the heavy lifting is passed on to the QueueManager's service()
* method, which passes control back to our handle_notice() method for
* each notice that comes in on the queue.
*
* Most of the time this won't need to be overridden in a subclass.
*
* @return boolean true on success, false on failure
*/
function run()
{
if (!$this->start()) {
@ -100,6 +169,14 @@ class QueueHandler extends Daemon
return true;
}
/**
* Called by QueueHandler after each handled item or empty polling cycle.
* This is a good time to e.g. service your XMPP connection.
*
* Doesn't need to be overridden if there's no maintenance to do.
*
* @param int $timeout seconds to sleep if there's nothing to do
*/
function idle($timeout=0)
{
if ($timeout > 0) {