[Python] RPC实现

 1 // 输入
 2 {
 3     in: "ping",
 4     params: "ireader 0"
 5 }
 6 
 7 // 输出
 8 {
 9     out: "pong",
10     result: "ireader 0"
11 }

 1 # coding: utf-8
 2 # client.py
 3 
 4 import json
 5 import time
 6 import struct
 7 import socket
 8 
 9 
10 def rpc(sock, in_, params):
11     response = json.dumps({"in": in_, "params": params})  # 请求消息体
12     length_prefix = struct.pack("I", len(response)) # 请求长度前缀
13     sock.sendall(length_prefix)
14     sock.sendall(response)
15     length_prefix = sock.recv(4)  # 响应长度前缀
16     length, = struct.unpack("I", length_prefix)
17     body = sock.recv(length) # 响应消息体
18     response = json.loads(body)
19     return response["out"], response["result"]  # 返回响应类型和结果
20 
21 if __name__ == ‘__main__‘:
22     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
23     s.connect(("localhost", 8080))
24     for i in range(10): # 连续发送10个rpc请求
25         out, result = rpc(s, "ping", "ireader %d" % i)
26         print out, result
27         time.sleep(1)  # 休眠1s，便于观察
28     s.close() # 关闭连接

 1 # coding: utf8
 2 # blocking_single.py
 3 
 4 import json
 5 import struct
 6 import socket
 7 
 8 
 9 def handle_conn(conn, addr, handlers):
10     print addr, "comes"
11     while True:  # 循环读写
12         length_prefix = conn.recv(4)  # 请求长度前缀
13         if not length_prefix:  # 连接关闭了
14             print addr, "bye"
15             conn.close()
16             break  # 退出循环，处理下一个连接
17         length, = struct.unpack("I", length_prefix)
18         body = conn.recv(length)  # 请求消息体  
19         request = json.loads(body)
20         in_ = request[‘in‘]
21         params = request[‘params‘]
22         print in_, params
23         handler = handlers[in_]  # 查找请求处理器
24         handler(conn, params)  # 处理请求
25 
26 
27 def loop(sock, handlers):
28     while True:
29         conn, addr = sock.accept()  # 接收连接
30         handle_conn(conn, addr, handlers)  # 处理连接
31 
32 
33 def ping(conn, params):
34     send_result(conn, "pong", params)
35 
36 
37 def send_result(conn, out, result):
38     response = json.dumps({"out": out, "result": result})  # 响应消息体
39     length_prefix = struct.pack("I", len(response))  # 响应长度前缀
40     conn.sendall(length_prefix)
41     conn.sendall(response)
42 
43 
44 if __name__ == ‘__main__‘:
45     sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  # 创建一个TCP套接字
46     sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)  # 打开reuse addr选项
47     sock.bind(("localhost", 8080)) # 绑定端口
48     sock.listen(1)  # 监听客户端连接
49     handlers = {  # 注册请求处理器
50         "ping": ping
51     }
52     loop(sock, handlers)  # 进入服务循环