An example of a worker written in PHP that collects user statistics

CollectUserStatsWorker.php

<?php

namespace Tib\CoreBundle\Job\Worker;

use Tib\CoreBundle\Exception\APIException;
use Tib\CoreBundle\Exception\InvalidDataException;
use Tib\CoreBundle\Util\JsonResponseTrait;

/**
 * Class CollectUserStatsWorker collects user information and records it to a table
 * @package Tib\CoreBundle\Job\Worker
 */
class CollectUserStatsWorker extends AbstractWorker
{
    use JsonResponseTrait;

    /**
     * Collect user stats and store in a table
     * @throws InvalidDataException
     * @throws APIException
     * @return bool
     */
    public function perform()
    {
        $args = $this->getArgs();
        if (empty($args)) {
            throw new InvalidDataException('No client stats were recorded as no arguments were found');
        }

        // Ignore all symfony profiler requests
        if (preg_match('/_wdt/', $args['uri'])) {
            return false;
        }

        // Ignore all requests that log the position of the currently playing track
        if (preg_match('/log_position/', $args['uri'])) {
            return false;
        }

        $db = $this->getContainer()->get('db2');;

        $userAgent = isset($args['user_agent']) ? $args['user_agent'] : null;
        $cookie = isset($args['cookie']) ? $args['cookie'] : null;
        $requestTime = isset($args['request_time']) ? $args['request_time'] : strtotime('now');
        $requestTime = date('Y-m-d h:i:s', $requestTime);
        $clientIp = isset($args['client_ip']) ? $args['client_ip'] : null;
        $queryString = isset($args['query_string']) ? $args['query_string'] : null;
        $uri = isset($args['uri']) ? $args['uri'] : null;
        $sessionId = isset($args['session_id']) ? $args['session_id'] : null;

        // Attempt to locate an existing record
        $query = '
        select
            id
        from
            ill_stats
        where
            uri = :uri
            and ip = :ip
            and session_id = :sessionId';

        $row = $db->fetchRow($query, array(
            'uri' => $uri,
            'ip' => $clientIp,
            'sessionId' => $sessionId
        ));

        $id = !empty($row) && isset($row['id']) ? $row['id'] : null;

        if (empty($id)) { // Create a new record

            return $db->insert('ill_stats', array(
                'user_agent' => $userAgent,
                'cookie' => $cookie,
                'request_time' => $requestTime,
                'ip' => $clientIp,
                'query_string' => $queryString,
                'uri' => $uri,
                'session_id' => $sessionId,
                'num_hits' => 1
            ));

        } else { // Don't count the same page view twice, assume the user is refreshing the page, just increment a counter

            $query = 'select num_hits from ill_stats where id = :id';
            $row = $db->fetchRow($query, array('id' => $id));
            $numHits = $row['num_hits'];

            return $db->update('ill_stats',
                array('id' => $id, 'request_time' => $requestTime),
                array('num_hits' => ++$numHits)
            );
        }
    }
}