基于System V Message queue的PHP消息队列封装

原创文章，转载请注明出处： http://www.huyanping.cn/?p=235
作者： Jenner

System V Message queue 是一种进程通信（IPC）的方式，方便实现生产者-消费者模型，单个或多个生产者向队列中写入消息，多个生产者再从队列中获取消息进行处理。

项目地址：https://github.com/huyanping/Zebra-PHP-Framework

该Wrapper支持：

1. 进程通信
2. 设置最大队列容量（字节单位）
3. 获取当前队列数量
4. 修改队列部分属性

注意：如果要修改队列最大容量，请确保你的脚本是运行在root下

msg_type = $msg_type;
        $this->serialize_needed = $serialize_needed;
        $this->block_send = $block_send;
        $this->option_receive = $option_receive;
        $this->maxsize = $maxsize;
        $this->init_queue($ipc_filename, $msg_type);
    }

    /**
     * 初始化一个队列
     * @param $ipc_filename
     * @param $msg_type
     * @throws Exception
     */
    public function init_queue($ipc_filename, $msg_type)
    {
        $this->key_t = $this->get_ipc_key($ipc_filename, $msg_type);
        $this->queue = msg_get_queue($this->key_t);
        if (!$this->queue) throw new Exception('msg_get_queue failed');
    }

    /**
     * @param $ipc_filename
     * @param $msg_type
     * @return int
     * @throws Exception
     */
    public function get_ipc_key($ipc_filename, $msg_type)
    {
        $key_t = ftok($ipc_filename, $msg_type);
        if ($key_t == 0) throw new Exception('ftok error');

        return $key_t;
    }

    /**
     * 从队列获取一个
     * @return bool
     * @throws Exception
     */
    public function get()
    {
        $queue_status = $this->status();
        if ($queue_status['msg_qnum'] > 0) {
            if (msg_receive($this->queue, $this->msg_type, $msgtype_erhalten, $this->maxsize, $data, $this->serialize_needed, $this->option_receive, $err) === true) {
                return $data;
            } else {
                throw new Exception($err);
            }
        } else {
            return false;
        }
    }

    /**
     * 写入队列
     * @param $message
     * @throws Exception
     */
    public function put($message)
    {
        if (!msg_send($this->queue, $this->msg_type, $message, $this->serialize_needed, $this->block_send, $err) === true) {
            throw new Exception($err);
        }

        return true;
    }

    /*
     * 返回值数组下标如下：
     * msg_perm.uid	 The uid of the owner of the queue. 用户ID
     * msg_perm.gid	 The gid of the owner of the queue. 用户组ID
     * msg_perm.mode	 The file access mode of the queue. 访问模式
     * msg_stime	 The time that the last message was sent to the queue. 最后一次队列写入时间
     * msg_rtime	 The time that the last message was received from the queue.  最后一次队列接收时间
     * msg_ctime	 The time that the queue was last changed. 最后一次修改时间
     * msg_qnum	 The number of messages waiting to be read from the queue. 当前等待被读取的队列数量
     * msg_qbytes	 The maximum number of bytes allowed in one message queue.  一个消息队列中允许接收的最大消息总大小
     *               On Linux, this value may be read and modified via /proc/sys/kernel/msgmnb.
     * msg_lspid	 The pid of the process that sent the last message to the queue. 最后发送消息的进程ID
     * msg_lrpid	 The pid of the process that received the last message from the queue. 最后接收消息的进程ID
     *
     * @return array
     */
    public function status()
    {
        $queue_status = msg_stat_queue($this->queue);
        return $queue_status;
    }

    /**
     * 获取队列当前堆积状态
     * @return mixed
     */
    public function size()
    {
        $status = $this->status();
        return $status['msg_qnum'];
    }


    /**
     * allows you to change the values of the msg_perm.uid,
     * msg_perm.gid, msg_perm.mode and msg_qbytes fields of the underlying message queue data structure
     * 可以用来修改队列运行接收的最大读取的数据
     *
     * @param $key 状态下标
     * @param $value 状态值
     * @return bool
     */
    public function set_status($key, $value)
    {
        $this->check_set_privilege($key);

        if ($key == 'msg_qbytes')
            return $this->set_max_queue_size($value);

        $queue_status[$key] = $value;
        return msg_set_queue($this->queue, $queue_status);
    }

    /**
     * 删除一个队列
     * @return bool
     */
    public function queue_remove()
    {
        return msg_remove_queue($this->queue);
    }

    //修改队列能容纳的最大字节数，需要root权限
    /**
     * @param $size
     * @return bool
     * @throws Exception
     */
    public function set_max_queue_size($size)
    {
        $user = get_current_user();
        if ($user !== 'root')
            throw new Exception('changing msg_qbytes needs root privileges');

        return $this->set_status('msg_qbytes', $size);
    }

    /**
     * 判断一个队列是否存在
     * @param $key
     * @return bool
     */
    public function queue_exists($key)
    {
        return msg_queue_exists($key);
    }

    /**
     * 检查修改队列状态的权限
     * @param $key
     * @throws Exception
     */
    private function check_set_privilege($key)
    {
        $privilege_field = array('msg_perm.uid', 'msg_perm.gid', 'msg_perm.mode');
        if (!in_array($key, $privilege_field)) {
            throw new Exception('you can only change msg_perm.uid, msg_perm.gid, msg_perm.mode and msg_qbytes. And msg_qbytes needs root privileges');
        }
    }
} 

调用方式如下：

写入队列：

put(mt_rand(0, 1000)));
        echo $messageQueue->size() . PHP_EOL;
        sleep(1);
    }
}catch(Exception $e){
    echo $e->getMessage();
}

获取队列：

get());
        sleep(1);
    }
}catch(Exception $e){
    echo $e->getMessage();
}

删除队列：

queue_remove());
}catch(Exception $e){
    echo $e->getMessage();
}