AMQP + NodeJS等待频道

问题描述

我在FeathersJS中有一个服务可以启动与RabbitMQ的连接，问题是如何在接收请求之前等待通道准备就绪：

class Service {
  constructor({ amqpConnection,queueName }) {
    this.amqpConnection = amqpConnection;
    this.queueName = queueName;
    this.replyQueueName = queueName + "Reply"
  }

  async create(data,params) {
    new Promise(resolve => {
      if (!this.channel) await this.createChannel();
      channel.responseEmitter.once(correlationId,resolve);
      channel.sendToQueue(this.queueName,Buffer.from(data),{
        correlationId: asyncLocalStorage.getStore(),replyTo: this.replyQueueName,});
    });
  }

  async createChannel() {
    let connection = this.amqpConnection();
    let channel = await connection.createChannel();

    await channel.assertQueue(this.queueName,{
      durable: false,});

    this.channel = channel;
    channel.responseEmitter = new EventEmitter();
    channel.responseEmitter.setMaxListeners(0);
    channel.consume(
      this.replyQueueName,(msg) => {
        channel.responseEmitter.emit(
          msg.properties.correlationId,msg.content.toString("utf8")
        );
      },{ noAck: true }
    );
  }
  ....
}

等待请求期间创建频道似乎是一种浪费。该如何“正确”完成？

解决方法

羽毛服务可以实现setup method，它将在服务器启动时被调用（或者您自己调用app.setup()）：

class Service {
  async setup () {
    await this.createChannel();
  }
}