CRestServer::processCall

protected function processCall()
{
	if (
		LoadLimiter::is(
			$this->getAuthType(),
			!empty($this->getClientId()) ?  $this->getClientId() : $this->getPasswordId(),
			$this->method
		)
	)
	{
		throw new RestException('Method is blocked due to operation time limit.', RestException::ERROR_OPERATION_TIME_LIMIT, self::STATUS_TO_MANY_REQUESTS);
	}

	$start = 0;
	if(isset($this->query['start']))
	{
		$start = intval($this->query['start']);
		unset($this->query['start']);
	}

	$callback = $this->getMethodCallback();

	if(!$callback)
	{
		throw new RestException('Method not found!', RestException::ERROR_METHOD_NOT_FOUND, self::STATUS_NOT_FOUND);
	}

	$this->timeProcessStart = microtime(true);

	if(BitrixMainModuleManager::isModuleInstalled('bitrix24') && function_exists('getrusage'))
	{
		$this->usage = getrusage();
	}

	$entity = !empty($this->getClientId()) ?  $this->getClientId() : $this->getPasswordId();
	LoadLimiter::registerStarting(
		$this->getAuthType(),
		$entity,
		$this->method
	);
	$result = call_user_func_array($callback, array($this->query, $start, $this));
	LoadLimiter::registerEnding(
		$this->getAuthType(),
		$entity,
		$this->method
	);
	$this->timeProcessFinish = microtime(true);

	if (!empty($result['error']) && !empty($result['error_description']))
	{
		return $result;
	}

	$result = array("result" => $result);
	if(is_array($result['result']))
	{
		if(isset($result['result']['next']))
		{
			$result["next"] = intval($result['result']['next']);
			unset($result['result']['next']);
		}

		//Using array_key_exists instead isset for process NULL values
		if(array_key_exists('total', $result['result']))
		{
			$result['total'] = intval($result['result']['total']);
			unset($result['result']['total']);
		}
	}

	if($this->securityClientState != null && $this->securityMethodState != null)
	{
		$result['signature'] = $this->getApplicationSignature();
	}

	$result = $this->appendDebugInfo($result);

	return $result;
}