Cron запуск

abstract class AbstractJob {
    
    protected $_websoccer;
    protected $_db;
    protected $_i18n;
    
    private $_id;
    private $_interval;
    
    /**
     * 
     * @param WebSoccer $websoccer request context.
     * @param DbConnection $db database connection-
     * @param I18n $i18n messages context.
     * @param string $jobId Job ID as defined at jobs.xml.
     * @param $errorOnAlreadyRunning boolean TRUE if error shall occur on init time when an instance of this job is already running.
     */
    function __construct(WebSoccer $websoccer, DbConnection $db, I18n $i18n, $jobId, $errorOnAlreadyRunning = TRUE) {
        $this->_websoccer = $websoccer;
        $this->_db = $db;
        $this->_i18n = $i18n;
        
        $this->_id = $jobId;
        
        $xmlConfig = $this->getXmlConfig();
        
        // check if another instance is running (consider timeout of 5 minutes)
        if ($errorOnAlreadyRunning) {
            $initTime = (int) $xmlConfig->attributes()->inittime;
            $now = $websoccer->getNowAsTimestamp();
            $timeoutTime = $now - 5 * 60;
            if ($initTime > $timeoutTime) {
                //throw new Exception('Another instance of this job is already running.');
                echo 'Another instance of this job is already running.';
            }
            $this->replaceAttribute('inittime', $now);
        }
        
        $interval = (int) $xmlConfig->attributes()->interval;
        $this->_interval = $interval * 60;
        
        ignore_user_abort(TRUE);
        // run possibly forever
        set_time_limit(0);
        
        // enable garbage collection (in case it is disabled by default)
        gc_enable();
    }
    
    /**
     * Destructor resets marker for checking the only instance.
     */
    function __destruct() {
        // little hack: set the ping so that 'last execution' also works for external job executions.
        // Better solution would be a AOP implementation which creates an interceptor for execute() function,
        // but for now this should also lead to the same behavior.
        $this->_ping($this->_websoccer->getNowAsTimestamp());
        
        //$this->replaceAttribute('inittime', 0);
    }
    
    /**
     * Starts the job. Pauses the script after each iteration.
     */
    public function start() {
        
        // reset stopping
        $this->replaceAttribute('stop', '0');
        $this->replaceAttribute('error', '');
        $this->_ping(0);
        
        do {
            
            $xmlConfig = $this->getXmlConfig();
            $stop = (int) $xmlConfig->attributes()->stop;
            if ($stop === 1) {
                $this->stop();
            }
            
            $now = $this->_websoccer->getNowAsTimestamp();
            
            // check if lastping has been set by another job. then this job became obsolete
            $lastPing = (int) $xmlConfig->attributes()->last_ping;
            if ($lastPing > 0) {
                $myOwnLastPing = $now - $this->_interval + 5; //plus tolerance
                if ($lastPing > $myOwnLastPing) {
                    exit;
                }
            }
            
            $this->_ping($now); 
                
            try {
                // reconnect to db
                $this->_db->close();
                $this->_db->connect($this->_websoccer->getConfig('db_host'),
                    $this->_websoccer->getConfig('db_user'),
                    $this->_websoccer->getConfig('db_passwort'),
                    $this->_websoccer->getConfig('db_name'));
                
                $this->execute();
                
                // force freeing memory by garbage collector
                gc_collect_cycles();
            } catch (Exception $e) {
                $this->replaceAttribute('error', $e->getMessage());
                $this->stop();
            }
                
            $this->_db->close();
            
            sleep($this->_interval);
        } while(true);
    }
    
    /**
     * Stops the job.
     */
    public function stop() {
        $this->replaceAttribute('stop', '1');
        
        exit;
    }
    
    private function _ping($time) {
        $this->replaceAttribute('last_ping', $time);
    }
    
    private function getXmlConfig() {
        $xml = simplexml_load_file(JOBS_CONFIG_FILE);
        $xmlConfig = $xml->xpath('//job[@id = \''. $this->_id . '\']');
        if (!$xmlConfig) {
            throw new Exception('Job config not found.');
        }
        
        return $xmlConfig[0];
    }
    
    private function replaceAttribute($name, $value) {
        
        // lock file for this transaction
        $fp = fopen(BASE_FOLDER . '/admin/config/lockfile.txt', 'r');
        flock($fp, LOCK_EX);
        
        $xml = simplexml_load_file(JOBS_CONFIG_FILE);
        if ($xml === FALSE) {
            
            $errorMessages = '';
            $errors = libxml_get_errors();
            foreach ($errors as $error) {
                $errorMessages = $errorMessages . "\n" . $error;
            }
            throw new Exception('Job with ID \'' . $this->_id . '\': Could not update attribute \'' . $name . '\' with value \'' . $value . '\'. Errors: ' . $errorMessages);
        }
        $xmlConfig = $xml->xpath('//job[@id = \''. $this->_id . '\']');
        $xmlConfig[0][$name] = $value;
        $successfulWritten = $xml->asXML(JOBS_CONFIG_FILE);
        if (!$successfulWritten) {
            throw new Exception('Job with ID \'' . $this->_id . '\': Could not save updated attribute \'' . $name . '\' with value \'' . $value . '\'.');
        }
        
        // unlock
        flock($fp, LOCK_UN);
    }
    
    /**
     * Execute this job by calling program code.
     */
    abstract function execute();
}
 
?>