Firebase Cloud Functions等待变量

Question

我想将img_thumb_url写入firebase数据库。在func1A中，我在下面编写了代码，我希望当全局变量room和msg_key不为null时，它可以突破while循环，但是我发现它始终是未定义的，尽管当func2B成功触发时，这些变量已使用字符串值定义了。

...
            while(1){
                if(room!=null && msg_key!=null){
                    console.log('room is ', room, '. msg_key is ', msg_key);
                    console.log('break from the loop');
                    break;
                }
            }
            admin.initializeApp();
             return admin.database().ref('/msgs/' + room + '/chat/' + msg_key + '/attachment/photo/thumbnail/url2').set(img_thumb_url);

             })

但是''/ msgs /'+ room +'/ chat /'+ msg_key +'/ attachment / photo / thumbnail / url2'上方的路径取决于从此处的其他函数func2B检索到的变量room和msg_key，< / p>

exports.func2B = functions.database.ref('/msgs/{roomName}/chat/{pushid}')
    .onCreate((snapshot, context) => {
        // Grab the current value of what was written to the Realtime Database.
        const msg = snapshot.val();
        if (msg.attachPhotoUrl == null) {
            console.log('No photo attachment found');
            return null;
        }
        if (msg_key != null) {
            console.log('msg_key no longer null');
            return null;
        }

       console.log('writing url2 for thumbnail in firebase database...');

        msg_key = msg.key;
        room = msg.roomName;
        console.log('room is ',room);
        console.log('msg_key is ',msg_key);
        console.log('img_thumb_url: ',img_thumb_url);
      return ....
    });

我不确定这是否是正确的方法，但我认为这不是那么简单。请帮我解决。如何将func2B中的赋值变量room和msg_key转换为func1A？