Python basehttpserver无法正确提供请求 [英] Python basehttpserver not serving requests properly
问题描述
我正在尝试为javascript写下一个简单的本地代理：因为我需要从网页中的javascript中加载一些东西，我在python中写了这个简单的守护进程：
I'm trying to write down a simple local proxy for javascript: since I need to load some stuff from javascript within a web page, I wrote this simple daemon in python:
import string,cgi,time
from os import curdir, sep
import urllib
import urllib2
from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
class MyHandler(BaseHTTPRequestHandler):
def fetchurl(self, url, post, useragent, cookies):
headers={"User-Agent":useragent, "Cookie":cookies}
url=urllib.quote_plus(url, ":/?.&-=")
if post:
req = urllib2.Request(url,post,headers)
else:
req=urllib2.Request(url, None, headers)
try:
response=urllib2.urlopen(req)
except urllib2.URLError, e:
print "URLERROR: "+str(e)
return False
except urllib2.HTTPError, e:
print "HTTPERROR: "+str(e)
return False
else:
return response.read()
def do_GET(self):
if self.path != "/":
[callback, url, post, useragent, cookies]=self.path[1:].split("%7C")
print "callback = "+callback
print "url = "+url
print "post = "+post
print "useragent = "+useragent
print "cookies = "+cookies
if useragent=="":
useragent="pyjproxy v. 1.0"
load=self.fetchurl(url, post, useragent, cookies)
pack=load.replace("\\", "\\\\").replace("\"", "\\\"").replace("\n", "\\n").replace("\r", "\\r").replace("\t", "\\t").replace(" </script>", "</scr\"+\"ipt>")
response=callback+"(\""+pack+"\");"
if load:
self.send_response(200)
self.send_header('Content-type', 'text/javascript')
self.end_headers()
self.wfile.write(response)
self.wfile.close()
return
else:
self.send_error(404,'File Not Found: %s' % self.path)
return
else:
embedscript="function pyjload(datadict){ if(!datadict[\"url\"] || !datadict[\"callback\"]){return false;} if(!datadict[\"post\"]) datadict[\"post\"]=\"\"; if(!datadict[\"useragent\"]) datadict[\"useragent\"]=\"\"; if(!datadict[\"cookies\"]) datadict[\"cookies\"]=\"\"; var oHead = document.getElementsByTagName('head').item(0); var oScript= document.createElement(\"script\"); oScript.type = \"text/javascript\"; oScript.src=\"http://localhost:1180/\"+datadict[\"callback\"]+\"%7C\"+datadict[\"url\"]+\"%7C\"+datadict[\"post\"]+\"%7C\"+datadict[\"useragent\"]+\"%7C\"+datadict[\"cookies\"]; oHead.appendChild( oScript);}"
self.send_response(200)
self.send_header("Content-type", "text/html")
self.end_headers()
self.wfile.write(embedscript)
self.wfile.close()
return
def main():
try:
server = HTTPServer(('127.0.0.1', 1180), MyHandler)
print 'started httpserver...'
server.serve_forever()
except KeyboardInterrupt:
print '^C received, shutting down server'
server.socket.close()
if __name__ == '__main__':
main()
我在这样的网页中使用：
And I use within a web page like this one:
<!DOCTYPE HTML>
<html><head>
<script>
function miocallback(htmlsource)
{
alert(htmlsource);
}
</script>
<script type="text/javascript" src="http://localhost:1180"></script>
</head><body>
<a onclick="pyjload({'url':'http://www.google.it','callback':'miocallback'});"> Take the Red Pill</a>
</body></html>
现在，Firefox和Chrome看起来总是有效。然而，在Opera和Internet Explorer上，我注意到有时候它不起作用，或者它挂了很多时间......我想知道怎么了？我错了什么吗？
Now, on Firefox and Chrome looks like it works always. On Opera and Internet Explorer, however, I noticed that sometimes it doesn't work, or it hangs for a lot of time... what's up, I wonder? Did I misdo something?
感谢您的帮助！
Matteo
Thank for any help! Matteo
推荐答案
您必须了解（现代）浏览器尝试使用不同的技术优化其浏览速度，这就是为什么你在不同的浏览器上得到不同的结果。
You have to understand that (modern) browsers try to optimize their browsing speed using different techniques, which is why you get different results on different browsers.
在你的情况下，导致你麻烦的技术是并发HTTP / 1.1会话设置：为了更好地利用你的带宽，您的浏览器可以同时启动多个HTTP / 1.1会话。这允许同时检索多个资源（例如图像）。
In your case, the technique that caused you trouble is concurrent HTTP/1.1 session setup: in order to utilize your bandwidth better, your browser is able to start several HTTP/1.1 sessions at the same time. This allows to retrieve multiple resources (e.g. images) simultaneously.
然而，当您的浏览器尝试打开另一个时， BaseHTTPServer没有线程连接，它将无法这样做，因为BaseHTTPServer已被第一个仍处于打开状态的会话阻止。请求永远不会到达服务器并进入超时状态。这也意味着只有一个用户可以在给定时间访问您的服务。不方便？是的，但是帮助就在这里：
However, BaseHTTPServer is not threaded: as soon as your browser tries to open another connection, it will fail to do so because BaseHTTPServer is already blocked by the first session that's still open. The request will never reach the server and run into a timeout. This also means that only one user can access your service at a given time. Inconvenient? Aye, but help is here:
线程！ ..和python让这个变得相当简单：
Threads! .. and python makes this one rather easy:
使用套接字服务器中的MixIn从HTTPServer派生一个新类。
Derive a new class from HTTPServer using a MixIn from socketserver.
。
from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
from SocketServer import ThreadingMixIn
import threading
class Handler(BaseHTTPRequestHandler):
def do_HEAD(self):
pass
def do_GET(self):
pass
class ThreadedHTTPServer(ThreadingMixIn, HTTPServer):
""" This class allows to handle requests in separated threads.
No further content needed, don't touch this. """
if __name__ == '__main__':
server = ThreadedHTTPServer(('localhost', 80), Handler)
print 'Starting server on port 80...'
server.serve_forever()
从现在开始，BaseHTTPServer已经过线程化，可以同时为多个连接（因此请求）提供服务，这将解决您的问题。
From now on, BaseHTTPServer is threaded and ready to serve multiple connections ( and therefore requests ) at the same time which will solve your problem.
而不是ThreadingMixIn，你也可以使用ForkingMixIn来产生另一个进程而不是另一个进程。
Instead of the ThreadingMixIn, you can also use the ForkingMixIn in order to spawn another process instead of another thread.
所有最好的，
creo
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