Python通过RabbitMQ实现RPC

Client端代码：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import pika
import uuid
import time

class FibonacciRpcClient(object):
    def __init__(self):
        #生成socket
        self.connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
        #生成管道
        self.channel = self.connection.channel()
        #声明一个随机queue，exclusive=True会在此queue的消费者断开后，自动将queue删除
        result = self.channel.queue_declare(exclusive=True)
        #获取随机queue名
        self.callback_queue = result.method.queue
        #定义收到消息后的动作
        self.channel.basic_consume(self.on_response,       #回调函数on_response
                                   no_ack=True,
                                   queue=self.callback_queue)    #获取随机queue名

    def on_response(self, ch, method, props, body):
        if self.corr_id == props.correlation_id:  #判断uuid是否是否一致
            self.response = body        #队列返回

    def call(self, n):
        self.response = None
        self.corr_id = str(uuid.uuid4()) #生成uuid，等会发送给服务端
        #发送消息给服务端
        self.channel.basic_publish(exchange='',
                                   routing_key='rpc_queue',   #路由键
                                   properties=pika.BasicProperties(reply_to=self.callback_queue,  #告诉服务端将返回发到哪个队列
                                                                   correlation_id=self.corr_id),
                                   body=str(n))    #发送的消息
        while self.response is None:
            self.connection.process_data_events()   #非阻塞版的start_consuming()，如果收到消息就执行on_response回调函数
            print("no msg....")
            time.sleep(0.5)         #这里可以执行其他命令
        return int(self.response)   #返回结果

#生成实例
fibonacci_rpc = FibonacciRpcClient()

print("[x] Requesting fib(30)")

#调用call函数
response = fibonacci_rpc.call(30)

print("[x] got %r " % response)

server端代码：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import pika
import time

#生成socket
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
#生成管道
channel = connection.channel()
#声明一个queue防止启动报错
channel.queue_declare(queue='rpc_queue')

def fib(n):
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return fib(n - 1) + fib(n - 2)

def on_request(ch, method, props, body):
    n = int(body)

    print("[.] fib(%s)" % n)
    response = fib(n)

    ch.basic_publish(exchange='',
                     routing_key=props.reply_to,
                     properties=pika.BasicProperties(correlation_id=props.correlation_id),
                     body=str(response))

    ch.basic_ack(delivery_tag=method.delivery_tag)  #回复确认消息

#处理完这条再发下一条
channel.basic_qos(prefetch_count=1)
#定义收到消息动作
channel.basic_consume(on_request,queue='rpc_queue')

channel.start_consuming()