How to develop a chat room with PHP

public function start()
{
   $this->lock = new swoole_lock(SWOOLE_MUTEX);　　　　　　　　　　　　
 
   // 对文件或数组进行锁操作，已达到同步
   $this->server = new swoole_websocket_server($this->addr, $this->port);　　
 
   // swoole提供的Websocket Server
   $this->server->set(array(
      'daemonize' => 0,
      'worker_num' => 4,
      'task_worker_num' => 10,
      'max_request' => 1000,
      'log_file' => ROOT_PATH . 'storage\\logs\\swoole.log'  
 
    // swoole日志路径，必须是绝对路径
   ));
 
   $this->server->on('open', array($this, 'onOpen'));
   $this->server->on('message', array($this, 'onMessage'));
   $this->server->on('task', array($this, 'onTask'));
   $this->server->on('finish', array($this, 'onFinish'));
   $this->server->on('close', array($this, 'onClose'));
 
　　 // 启动服务
   $this->server->start();
}

public function onOpen($server, $request)
    {
      $message = array(
        'remote_addr' => $request->server['remote_addr'],
        'request_time' => date('Y-m-d H:i:s', $request->server['request_time'])
      );
      write_log($message);
    }

public function onMessage($server, $frame)
    {
      $data = json_decode($frame->data);
 
      switch ($data->type) {
        case 'init':
        case 'INIT':
          $this->users[$frame->fd] = $data->message;　　、
 
      // 记录每个链接的信息，同样不要尝试打印出来看，因为你只能看到自己的链接信息
          $message = '欢迎' . $data->message . '加入了聊天室';
          $response = array(
            'type' => 1,  // 1代表系统消息，2代表用户聊天
            'message' => $message
          );
          break;
        case 'chat':
        case 'CHAT':
          $message = $data->message;
          $response = array(
            'type' => 2,  // 1代表系统消息，2代表用户聊天
            'username' => $this->users[$frame->fd],
            'message' => $message
          );
          break;
        default:
          return false;
      }
　　　　　　　　
　　　　　　　// 将信息交给task处理
      $this->server->task($response);
    }
 
    public function onTask($server, $task_id, $from_id, $message)
    {
　　　　　　　// 迭代所有的客户端链接，将消息推送过去。（如果你尝试将 $this->server->connections 打印出来，那么你会发现他是空的。但当时用 foreach 去循环时，它确实有用。）
      foreach ($this->server->connections as $fd) {
        $this->server->push($fd, json_encode($message));
      }
      $server->finish( 'Task' . $task_id . 'Finished' . PHP_EOL);
    }

public function onClose($server, $fd)
    {
      $username = $this->users[$fd];
      // 释放客户端，利用锁进行同步
      $this->lock->lock();
      unset($this->users[$fd]);
      $this->lock->unlock();
 
      if( $username ) {
        $response = array(
          'type' => 1,  // 1代表系统消息，2代表用户聊天
          'message' => $username . '离开了聊天室'
        );
        $this->server->task($response);
      }
 
 
      write_log( $fd . ' disconnected');
    }

// websocket
    let address = &#39;ws://<?php echo CLIENT_CONNECT_ADDR . &#39;:&#39; . CLIENT_CONNECT_PORT ?>&#39;;
    let webSocket = new WebSocket(address);
    webSocket.onerror = function (event) {
      alert(&#39;服务器连接错误，请稍后重试&#39;);
    };
    webSocket.onopen = function (event) {
      if(!sessionStorage.getItem(&#39;username&#39;)) {
        setName();
      }else {
        username = sessionStorage.getItem(&#39;username&#39;)
        webSocket.send(JSON.stringify({
          &#39;message&#39;: username,
          &#39;type&#39;: &#39;init&#39;
        }));
      }
    };
    webSocket.onmessage = function (event) {
      console.log(event);
      let data = JSON.parse(event.data);
      if (data.type == 1) {
        $(&#39;#chat-list2&#39;).append(&#39;<li class="ui-border-tb"><span class="username">系统消息:</span><span class="message">&#39; + data.message + &#39;</span></li>&#39;);
      } else if (data.type == 2) {
        $(&#39;#chat-list2&#39;).append(&#39;<li class="ui-border-tb"><span class="username">&#39; + data.username + &#39;:</span><span class="message">&#39; + data.message + &#39;</span></li>&#39;);
      }
 
    };
    webSocket.onclose = function (event) {
      alert(&#39;散了吧，服务器都关了&#39;);
    };