/**
* Wraps the complex pool counter interface to force the single call pattern
* that Cirrus always uses.
* @param $type same as type parameter on PoolCounter::factory
* @param $user the user
* @param $workCallback callback when pool counter is aquired. Called with
* no parameters.
* @param $errorCallback optional callback called on errors. Called with
* the error string and the key as parameters. If left undefined defaults
* to a function that returns a fatal status and logs an warning.
*/
public static function doPoolCounterWork($type, $user, $workCallback, $errorCallback = null)
{
global $wgCirrusSearchPoolCounterKey;
// By default the pool counter allows you to lock the same key with
// multiple types. That might be useful but it isn't how Cirrus thinks.
// Instead, all keys are scoped to their type.
if (!$user) {
// We don't want to even use the pool counter if there isn't a user.
return $workCallback();
}
$perUserKey = md5($user->getName());
$perUserKey = "nowait:CirrusSearch:_per_user:{$perUserKey}";
$globalKey = "{$type}:{$wgCirrusSearchPoolCounterKey}";
if ($errorCallback === null) {
$errorCallback = function ($error, $key, $userName) {
$forUserName = $userName ? "for {userName} " : '';
LoggerFactory::getInstance('CirrusSearch')->warning("Pool error {$forUserName}on {key}: {error}", array('userName' => $userName, 'key' => $key, 'error' => $error));
return Status::newFatal('cirrussearch-backend-error');
};
}
$errorHandler = function ($key) use($errorCallback, $user) {
return function ($status) use($errorCallback, $key, $user) {
$status = $status->getErrorsArray();
// anon usernames are needed within the logs to determine if
// specific ips (such as large #'s of users behind a proxy)
// need to be whitelisted. We do not need this information
// for logged in users and do not store it.
$userName = $user->isAnon() ? $user->getName() : '';
return $errorCallback($status[0][0], $key, $userName);
};
};
$doPerUserWork = function () use($type, $globalKey, $workCallback, $errorHandler) {
// Now that we have the per user lock lets get the operation lock.
// Note that this could block, causing the user to wait in line with their lock held.
$work = new PoolCounterWorkViaCallback($type, $globalKey, array('doWork' => $workCallback, 'error' => $errorHandler($globalKey)));
return $work->execute();
};
$work = new PoolCounterWorkViaCallback('CirrusSearch-PerUser', $perUserKey, array('doWork' => $doPerUserWork, 'error' => function ($status) use($errorHandler, $perUserKey, $doPerUserWork) {
$errorCallback = $errorHandler($perUserKey);
$errorResult = $errorCallback($status);
if (Util::isUserPoolCounterActive()) {
return $errorResult;
} else {
return $doPerUserWork();
}
}));
return $work->execute();
}