Node.js RabbitMq 싱글톤 적용하기

node.js 에서 rabbitmq를 사용하는데 매번 message가 보내질때마다 

connection이 생기고 channel이 생기는게 너무 비효율적이라고 생각 들어서

싱글톤으로 구현함 

import * as amqp from 'amqplib/callback_api';
import {URL} from 'url';


export interface Config {
  url: string;
  username: string;
  password: string;
}

export class RabbitMq {
  private connection: amqp.Connection | null
  private channel: amqp.Channel | null
  private config: Config;

  constructor(config: Config) {
    this.config = config;
    this.connection = null;
    this.channel = null;
  }

  private async getConnection(): Promise<amqp.Connection> {
    return new Promise<amqp.Connection>( (resolve, reject) => {
      if (this.connection) {
        resolve(this.connection);
      } else {
        const parsedUrl = new URL(this.config.url);
        const vhost = (parsedUrl.pathname.length > 1) ? parsedUrl.pathname : undefined;
        amqp.connect(this.config.url, {
          hostname: parsedUrl.hostname,
          vhost: vhost,
          port: parsedUrl.port ? parseInt(parsedUrl.port) : 5672,
          username: this.config.username,
          password: this.config.password
        }, (error: Error, connection: any) => {
          if (error) {
            reject();
          } else {
            this.connection = connection;
            resolve(connection);
          }
        });
      }
    });
  }

  private async getChannel(): Promise<amqp.Channel> {
    return new Promise<amqp.Channel>( (resolve, reject) => {
      if (this.channel) {
        resolve(this.channel);
      } else {
        this.getConnection().then(
          (connection) => {
            connection.createChannel(async (error: Error, channel: any) => {
              if (error) {
                reject();
              } else {
                this.channel = channel;
                resolve(channel);
              }
            });
          }
        ).catch(() => reject());
      }
    });
  }


  public publishMessage(message: Object) {
    this.getChannel().then(
      (channel) => {
        channel.publish('exchangeName', 'queueName', Buffer.from(JSON.stringify(message)));
      }
    ).catch(() => console.log('Failed to establish RabbitMQ'));
  }
}

 

2023-12-05 와서 생각해보니 stateless하게 connection을 만들고 끊는게 오히려 좋을 것 같다는 생각도 들었다..