python - 使用 SSE + 长轮询创建 Web 应用程序时出现的问题

Question

我是网络开发新手。我正在为我的家庭自动化项目创建一个网络应用程序，其中我需要双向通信。任何来自家的盗窃安全警报都将从服务器发送到客户端，或者如果客户端想要控制大门，他将向服务器发送 POST 请求。我仍然很困惑该使用什么，SSE 还是 Web 套接字。我的问题是，是否可以开发一个既使用 SSE 又处理来自客户端 (GET/POST) 的传统(长轮询)HTTP 请求的应用程序？我已经单独测试了它们，它们工作得很好，但我无法让它们一起工作。我正在使用 python BaseHTTPServer。或者最后，我必须转向 WebSocket 吗？任何建议将受到高度赞赏。我的代码是；

import time
import BaseHTTPServer
from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
from SocketServer import ThreadingMixIn

import os
import requests
import threading
from threading import Thread
from chk_connection import is_connected
import socket


HOST_NAME = socket.gethostbyname(socket.gethostname())
PORT_NUMBER = 8040 # Maybe set this to 9000.
ajax_count=0
ajax_count_str=""
switch=0
IP_Update_time=2 
keep_alive=0
connected=False


###############################

##############

my_dir = os.getcwd()


class MyHandler(BaseHTTPServer.BaseHTTPRequestHandler):
 def do_HEAD(s):
    s.send_response(200)
    s.send_header("Content-type", "text/html")
    s.end_headers()



def do_POST(s):

    global keep_alive

    """Respond to a POST request."""
    s.send_response(200)
    s.send_header('Access-Control-Allow-Origin', '*')
    s.send_header("Content-type", "text/html")
    s.end_headers()
    HTTP_request=s.requestline

    if HTTP_request.find('keep_alive')>-1:
             keep_alive += 1
             keep_alive_str = str(keep_alive)
             s.wfile.write(keep_alive_str)  #sending ajax calls for keep alive 




def do_GET(s):
    global ajax_count
    global my_dir
    global switch
    global ajax_count_str
    global keep_alive
    #print 'got Get',
    """Respond to a GET request."""
    s.send_response(200)
    #s.send_header('Access-Control-Allow-Origin', '*')
    s.send_header('content-type', 'text/html')
    s.end_headers()
    print s.headers
    HTTP_request=s.requestline
    index_1=HTTP_request.index("GET /")
    index_2=HTTP_request.index(" HTTP/1.1")
    file_name=HTTP_request[index_1+5:index_2]
    #print 'file_name:',file_name
    #print 'HTTP_request:',HTTP_request 
    #if len(file_name)>0:

    #if HTTP_request.find('L2ON')>-1:
    #        print 'sending SSE'
    #        s.wfile.write('event::'.format(time.time()))




    elif HTTP_request.find('GET / HTTP/1.1')>-1: 
        print 'send main'
        file1=open('Index.html','r')
        file_read=file1.read()
        s.wfile.write(file_read)


    elif file_name.find("/")==-1:
           for root, dirs, files in os.walk(my_dir):
               #print 'in for 1' 
               for file in files:
                 #print 'in for'  
                 if HTTP_request.find(file)>-1:
                    file_path=os.path.join(root,file)
                    file1=open(file_path,'r')
                    file_read=file1.read()
                    s.wfile.write(file_read)
                    print 'send',file

    elif file_name.find("/")>-1:
             #print 'get /...'
             slash_indexes=[n for n in xrange(len(file_name)) if file_name.find('/', n)==n]
             length=len(slash_indexes)
             slash=slash_indexes[length-1]
             file_path=file_name[0:slash]
             root_dir=(my_dir + '/' + file_path + '/')
             for root, dirs, files in os.walk(root_dir): 
               for file in files: 
                  if HTTP_request.find(file)>-1:
                    image_path=os.path.join(root,file)
                    image=open(image_path,'r')
                    image_read=image.read()
                    s.wfile.write(image_read)
                    print 'send',file
                  #else:
                    #print 'file not found'


class MyHandler_SSE(BaseHTTPRequestHandler):
 print 'SSE events class'
 def do_GET(self):
    print 'this is SSE'
    self.send_response(200)
    self.send_header('content-type', 'text/event-stream')
    self.end_headers()
    while True:
        print 'SSE sent'
        self.wfile.write('event: message\nid: 1\ndata: {0}\ndata:\n\n'.format(time.time()))
        time.sleep(2)





class chk_connection(threading.Thread):
  """
  # this thread checks weather there is internet connection available ? 
  """
  def __init__(self):
    threading.Thread.__init__(self)

  def run(self):
    global connected
    while 1:
     ########################################################## INSIDE THE            chk_connection import is_connected
    #import socket
    #REMOTE_SERVER = "www.google.com"
    #def is_connected():
    #try:
    #   # see if we can resolve the host name -- tells us if there is
    #   # a DNS listening
    #   host = socket.gethostbyname(REMOTE_SERVER)
        # connect to the host -- tells us if the host is actually
        # reachable
    #   s = socket.create_connection((host, 80), 2)
    #   return True
    #except:
    #   pass
    #return False
     ##########################################################
        connected=is_connected()
        #print 'internet:', connected
        time.sleep(1)


class server_main(threading.Thread):
 """


 """
 def __init__(self):
    threading.Thread.__init__(self)


 def run(self):
    global connected


    #print 'shutdown started'
    server_class = BaseHTTPServer.HTTPServer
    HOST_NAME = socket.gethostbyname(socket.gethostname())
    last_HOST_NAME = HOST_NAME
    httpd = server_class((HOST_NAME, PORT_NUMBER), MyHandler)
    #http_SSE = server_class((HOST_NAME, PORT_NUMBER), MyHandler_SSE)
    print time.asctime(), "Server Starts - %s:%s" % (HOST_NAME, PORT_NUMBER)
    while(1):       
      while is_connected():
        httpd._handle_request_noblock()
        #print 'no block'
        #http_SSE._handle_request_noblock()
      time.sleep(1)  
      HOST_NAME = socket.gethostbyname(socket.gethostname())
      if HOST_NAME != last_HOST_NAME:
          print 'Serving at new host:', HOST_NAME
      httpd = server_class((HOST_NAME, PORT_NUMBER), MyHandler)  


def start():

tx_socket_thread3 = chk_connection()   # this thread checks weather there is internet connection available ?
tx_socket_thread3.start()

tx_socket_thread5 = server_main()
tx_socket_thread5.start()
print 's1:',tx_socket_thread1.is_alive()

if __name__ == '__main__':

 start()

我可能需要以新的方式修改代码，但不知道如何修改。我想要的是，如果服务器端发生任何中断，它会将数据拉到客户端，同时它也响应来自客户端的 GET 和 POST 请求。帮助PLX...

Answer 1

开发一个混合使用普通 HTTP 流量、服务器端事件和 WebSocket 的 Web 应用程序是绝对可能的。然而，Python 标准库中的 Web 服务器类并不是为此目的而设计的，尽管可以通过足够的锤炼使它们工作。您应该安装适当的网络服务器并使用它的设施。

示例包括

• uWSGI and server-side events with WSGI applications
• Tornado and WebSockets

此外

• Installing Python packages