Introduction à la file d'attente PHPyii2 shmilyzxt/yii2-queue

//入队列public function pushOn($job, $data = '', $queue = null)
    {        //canPush 检查队列是否已达最大任务量
        if ($this->canPush()) {  
            //beforePush 入队列前的事件
            $this->trigger(self::EVENT_BEFORE_PUSH); 
            //入队列
            $ret = $this->push($job, $data, $queue);
            //afterPush 入队列后的事件
            $this->trigger(self::EVENT_AFTER_PUSH);
            return $ret;
        } else {            throw new \Exception("max jobs number exceed! the max jobs number is {$this->maxJob}");
        }
    }

/**  
 * 启用一个队列后台监听任务  
 * @param Queue $queue  
 * @param string $queueName 监听队列的名称(在pushon的时候把任务推送到哪个队列，则需要监听相应的队列才能获取任务)  
 * @param int $attempt 队列任务失败尝试次数，0为不限制  * @param int $memory 允许使用的最大内存  
 * @param int $sleep 每次检测的时间间隔  
 */
    public static function listen(Queue $queue, $queueName = 'default', $attempt = 10, $memory = 512, $sleep = 3, $delay = 0){        
        while (true){            
            try{               
                //DatabaseQueue从数据库队列取出一个可用任务(实例),并且更新任务
                $job = $queue->pop($queueName);
             }catch (\Exception $e){                
                throw $e;
                continue;
             }            
             if($job instanceof Job){                
                 //判断执行错误的次数是否大于传入的执行次数
                 if($attempt > 0 && $job->getAttempts() > $attempt){                    
                     $job->failed();
                 }else{                    
                     try{                        
                         //throw new \Exception("test failed");
                         $job->execute();
                      }catch (\Exception $e){                        
                          //执行失败,判断是否被删除,重新入队
                          if (! $job->isDeleted()) {                           
                              $job->release($delay);
                          }
                      }
                  }
               }else{                
                   self::sleep($sleep);
                }             
                if (self::memoryExceeded($memory)) {               
                    self::stop();
                }
               }
    }

    //取出一个任务
    public function pop($queue = null)
    {        $queue = $this->getQueue($queue);

        if (!is_null($this->expire)) {            //$this->releaseJobsThatHaveBeenReservedTooLong($queue);
        }        $tran = $this->connector->beginTransaction();
        //判断是否有一个可用的任务需要执行
        if ($job = $this->getNextAvailableJob($queue)) {            $this->markJobAsReserved($job->id);
            $tran->commit();

            $config = array_merge($this->jobEvent, [
                'class' => 'shmilyzxt\queue\jobs\DatabaseJob',
                'queue' => $queue,
                'job' => $job,
                'queueInstance' => $this,
            ]);

            return \Yii::createObject($config);

        }        $tran->commit();
        return false;
    }

/** 
 * 执行任务 
 */
public function execute(){   
  //beforeExecute 执行任务之前的一个事件 在JobEvent中并没有什么可执行的代码
  $this->trigger(self::EVENT_BEFORE_EXECUTE, new JobEvent(["job" => $this, 'payload' => $this->getPayload()]));
  $this->resolveAndFire();//真正执行的任务的方法
}

 /**   * 真正任务执行方法（调用hander的handle方法）   * @param  array $payload   * @return void */
    protected function resolveAndFire()
    {        $payload = $this->getPayload();
        $payload = unserialize($payload); //反序列化数据
        $type = $payload['type'];
        $class = $payload['job'];

        if ($type == 'closure' && ($closure = (new Serializer())->unserialize($class[1])) instanceof \Closure) {            
            $this->handler = $this->getHander($class[0]);
            $this->handler->closure = $closure;
            $this->handler->handle($this, $payload['data']);
        } else if ($type == 'classMethod') {            $payload['job'][0]->$payload['job'][1]($this, $payload['data']);
        } else if ($type == 'staticMethod') {            $payload['job'][0]::$payload['job'][1]($this, $payload['data']);
        } else {//执行的`SendMail`类的`handle($job,$data)`方法
            $this->handler = $this->getHander($class);
            $this->handler->handle($this, $payload['data']);
        }        //执行完任务后删除
        if (!$this->isDeletedOrReleased()) {            $this->delete();
        }
    }