WSGI原理

web_server:

 import socket
 import time
 import multiprocessing
 import re
 import mini_frame

 class WSGIServer(object):
     def __init__(self):
         # 1.创建socket对象
         self.tcp_server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         # 2.设置重复使用地址
         self.tcp_server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
         # 3.绑定端口
         self.tcp_server_socket.bind(("", 7890))
         # 4.设置监听状态
         self.tcp_server_socket.listen(128)

     def clinet_server(self,new_client_socket):
         # 1.接受消息
         request = new_client_socket.recv(1024).decode("utf-8")
         lines = request.splitlines()
         # 2.匹配请求网页
         request_name = re.match(r"[^/]+(/[^ ]*)",lines[0])
         file_name = request_name.group(1)
         if file_name == "/":
             file_name = "/index.html"

         # 返回数据给浏览器
         if not file_name.endswith(".py"):
             # 3.打开文件
             try:
                 f = open("./html" + file_name,"rb")
             except Exception as ret:
                 pass
             else:
                 html_content = f.read()

                 # 4.创建header和body
                 response_body = html_content
                 response_header = "HTTP/1.1 200 ok\r\n"
                 response_header += "Content-Length:%d\r\n" % len(response_body)
                 response_header += "\r\n"
                 response = response_header.encode("utf-8") + response_body
                 # 5.发送
                 new_client_socket.send(response)
             finally:
                 f.close()
         else:
             # 如果是.py结尾,则认为是动态页面请求/
             env = dict();
             env['PATH_INFO'] = file_name
             # application(字典， 方法名) 固定用法
             body = mini_frame.application(env, self.start_respones_header)
             # 拼装header头
             header = "HTTP/1.1 %s\r\n" % self.status
             for temp in self.headers:
                 header += "%s:%s\r\n" % (temp[0], temp[1])
             header += "\r\n"
             # 拼装返回数据
             response = header + body
             # 发送数据
             new_client_socket.send(response.encode("utf-8"))

         # 6.关闭socket
         # new_client_socket.close()

     def start_respones_header(self, status, headers):
         """接受并保存application传过来的值"""
         self.status = status
         self.headers = [("server","mini_web v1.0")]
         self.headers += headers

     def run_forever(self):
         """运行"""
         while True:
             # 5.接收客户地址，创建新socket
             new_client_socket,client_addr = self.tcp_server_socket.accept()
             # 6.为新客户端服务
             p = multiprocessing.Process(target=self.clinet_server,args=(new_client_socket,))
             p.start()
             # 7.关闭新客户端
             new_client_socket.close()
         # 7.关闭socket
         self.tcp_server_socket.close()

 def main():
     wsgi_server = WSGIServer()
     wsgi_server.run_forever()

 if __name__ == '__main__':
     main()

mini_frame.py:

 def login():
     """模拟登陆页面"""
     return "---login---welcome to python--->time:%s" % time.ctime()

 def index():
     """模拟主页"""
     return "----index----"

 def application(env, start_respones):
     # 调用传过来的方法，传值
     start_respones('200 ok',[("Content-Type","text/html;charset=utf-8")])
     # 接受字典传过来的数据
     file_name = env['PATH_INFO']
     # 判断客户请求
     if file_name == "/index.py":
         return index()
     elif file_name == "/login.py":
         return login()
     else:
         return "python 中国"