Rabbit MQ & NodeJS & Protobuf

Rabbit MQ & NodeJS & Protobuf

一、NodeJS Rabbit MQ 客户端封装

利用第三方库amqlib封装了一个简单的收发客户端。

// rabbit.js
/**
 * 对RabbitMQ的封装
 */
let amqp = require('amqplib');
class RabbitMQ {
    constructor() {
        this.hosts = ['amqp://192.168.94.105'];
        this.index = 0;
        this.length = this.hosts.length;
        this.open = amqp.connect({
            hostname:'192.168.94.105',
            port:5672,
            username:"lixin",
            password:"lixin"
        });
    }
    receiveQueueMsg(queueName, receiveCallBack, errCallBack) {
        let self = this;
        self.open.then(function (conn) {
            return conn.createChannel();
        }).then(function (channel) {
            return channel.assertQueue(queueName).then(function (ok) {
                return channel.consume(queueName, function (msg) {
                    if (msg !== null) {
                        //let data = msg.content.toString();
                        let data = msg.content;//binary data
                        channel.ack(msg);
                        receiveCallBack && receiveCallBack(data);
                    }
                }).finally(function () {
                    setTimeout(() => {
                        if (channel) {
                            channel.close();
                        }
                    }, 500)
                });
            })
        }).catch(function () {
            let num = self.index++;
            if (num <= self.length - 1) {
                self.open = amqp.connect(self.hosts[num]);
            } else {
                self.index = 0;
                self.open = amqp.connect(self.hosts[0]);
            }
        });
    }
    //msg 二进制流
    sendQueueMsg(queueName, msg, errCallBack) {
        let self = this;
        self.open.then(function (conn) {
                return conn.createChannel();
            }
        ).then(function (channel) {
            return channel.assertQueue(queueName).then(function (ok) {
                return channel.sendToQueue(queueName, (msg), {persistent: true});
            }).then(function (data) {
                if (data) {
                    errCallBack && errCallBack("success");
                    channel.close();
                }
            }).catch(function () {
                setTimeout(() => {
                    if (channel) {
                        channel.close();
                    }
                }, 500)
            });}).catch(function () {
            let num = self.index++;
            if (num <= self.length - 1) {
                self.open = amqp.connect(self.hosts[num]);
            } else {
                self.index = 0;
            }
        });
    }
}
exports.RabbitMQ =  RabbitMQ;

二、结合Protobuf

proto文件生成js

1. proto文件定义

syntax = "proto3";
message Test{
    string label = 1;
    int32 type = 2;
    int64 reps = 3;
}

2. 利用protoc程序在终端输入以下命令生成test_pb.js文件

.\protoc.exe --js_out=import_style=commonjs,binary:. .\test.proto

3. 生产者

//producer.js
let RabbitMQ = require('./rabbit').RabbitMQ;
let mq = new RabbitMQ();
var P = require('./test_pb');
var test = new P.Test();
test.setType(1);
test.setLabel("karl");
test.setReps(123);
var bit8Arr = test.serializeBinary();
setInterval(
 () => {
    mq.sendQueueMsg('testQueue', Buffer.from(bit8Arr), (error) => {
          console.log(error);
  })},10000);

4. 消费者

//consumer.js
pb = require('./test_pb.js');
let RabbitMQ = require('./rabbit').RabbitMQ;
let mq = new RabbitMQ();
setInterval(()=>{
    mq.receiveQueueMsg('testQueue',(msg) => 
    {
        var out = pb.Test.deserializeBinary(msg);
        console.log("Test{",out.getLabel(),":",out.getType(),":",out.getReps(),"}");
    })},500);

5. 验证

分别在两个终端运行 node consumer.js node producer.js 可以在消费者终端看到运行结果

Test{ karl : 1 : 123 }
Test{ karl : 1 : 123 }

可以看到已经正确消费protobuf消息。而对于json的传输也一样，相当于传送字符串，前一篇文章可以直接解出来。

三、总结

Rabbit MQ就是收发二进制流，至于怎么解析，看具体的协议的实现。