Twisted：服务器端进程完成时通知客户端

发布于 2024-11-05 18:18:29 字数 2066 浏览 1 评论 0原文

我正在使用 Twisted 编写网络服务器。该服务器执行的其中一项任务需要很长时间（约 5 分钟）。我希望能够有效地通知客户该任务已完成。

我已经研究过使用 Comet/长轮询，但在我的一生中，我无法让浏览器在收到数据时呈现数据。

为了构建此机制的原型，我编写了以下内容：

clock.py

from twisted.internet import reactor, task
from twisted.web.static import File
from twisted.web.server import Site
from twisted.web import server
from twisted.web.resource import Resource
import time

class Clock(Resource):
    def __init__(self):
        self.presence=[]
        loopingCall = task.LoopingCall(self.__print_time)
        loopingCall.start(1, False)
        Resource.__init__(self)

    def render_GET(self, request):
        print "request from",request.getClientIP()
        request.write(time.ctime())
        self.presence.append(request)
        return server.NOT_DONE_YET

    def __print_time(self):
        print "tick"
        for p in self.presence:
            print "pushing data to",p.getClientIP()
            p.write(time.ctime())

root = Resource()
clock = ClockPage()
index = File("index.html")
root.putChild("index.html",index)
root.putChild("clock",clock)
factory = Site(root)
reactor.listenTCP(8080, factory)
reactor.run()

index.html

<html>
<head>
</head>
<body>
<div id="data">Hello</div>
<script type="text/javascript">
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function(){
  if(xhttp.readyState == 4 && xhttp.status == 200){
    alert(xhttp.responseText);
    document.getElementById("data").innerHTML=xhttp.responseText;
  }
};
xhttp.open("GET","clock",true);
xhttp.send(null);
</script>
</body>
</html>

我在服务器端所做的就是调用 request.write 随着时间的推移，每一秒。

在客户端，我所做的就是打开一个 XMLHTTPRequest 到适当的资源，并在 .readyState == 4 和 .status 时将 responseText 直接转储到 div 中== 200。

问题是：div 永远不会被覆盖，警报也永远不会被调用。

我一直在阅读有关使用 multipart/x-mixed-replace 的内容，但我不太确定如何使用它。任何关于在扭曲中实现此类事情的教程或文档的指针将不胜感激。

原文

I'm using Twisted to write a web server. One of the tasks that this server performs takes a long time (~5 minutes). I would like to be able to efficiently notify the client that this task has completed.

I have looked into using Comet/long polling, but for the life of me I can't get the browser to render the data when it receives it.

To prototype this mechanism, I wrote the following:

clock.py

from twisted.internet import reactor, task
from twisted.web.static import File
from twisted.web.server import Site
from twisted.web import server
from twisted.web.resource import Resource
import time

class Clock(Resource):
    def __init__(self):
        self.presence=[]
        loopingCall = task.LoopingCall(self.__print_time)
        loopingCall.start(1, False)
        Resource.__init__(self)

    def render_GET(self, request):
        print "request from",request.getClientIP()
        request.write(time.ctime())
        self.presence.append(request)
        return server.NOT_DONE_YET

    def __print_time(self):
        print "tick"
        for p in self.presence:
            print "pushing data to",p.getClientIP()
            p.write(time.ctime())

root = Resource()
clock = ClockPage()
index = File("index.html")
root.putChild("index.html",index)
root.putChild("clock",clock)
factory = Site(root)
reactor.listenTCP(8080, factory)
reactor.run()

index.html

<html>
<head>
</head>
<body>
<div id="data">Hello</div>
<script type="text/javascript">
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function(){
  if(xhttp.readyState == 4 && xhttp.status == 200){
    alert(xhttp.responseText);
    document.getElementById("data").innerHTML=xhttp.responseText;
  }
};
xhttp.open("GET","clock",true);
xhttp.send(null);
</script>
</body>
</html>

What I've been doing on the server side is calling request.write with the time, every second.

On the client side, all I do is open a XMLHTTPRequest to the appropriate resource and dump the responseText directly into a div whenever .readyState == 4 and .status == 200.

The problem is: the div never gets overwritten and the alert is never called.

I keep reading about using multipart/x-mixed-replace, but I'm not really sure how to use it. Any pointers to tutorials or documentation on implementing this sort of thing in twisted would be greatly appreciated.

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