Asyncore

Fri Jan 7 06:41:38 EST 2005

export at hope.cz wrote:

> Is there any tutorial and docs with samples how to use asyncore module?
> Thanks 
> Lad
> 
Well, here's a very simple web server from Chapter 7 of "Python Web 
Programming" which might help get you started.

You can see a few more examples if you download the code from the book, 
which you can do at

     http://pydish.holdenweb.com/pwp/download.htm

--------
import socket
import asyncore
import time

class http_server(asyncore.dispatcher):

     def __init__(self, ip, port):
         self.ip= ip
         self.port = port
         self.count = 0
         asyncore.dispatcher.__init__(self)
         self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
         self.bind((ip, port))
         self.listen(5)

     def writable(self):
         return 0

     def handle_read(self):
         pass

     def readable(self):
         return self.accepting

     def handle_connect(self):
         pass

     def handle_accept(self):
         try:
             conn, addr = self.accept()
         except socket.error: # rare Linux error
             print "Socket error on server accept()"
             return
         except TypeError: # rare FreeBSD3 error
             print "EWOULDBLOCK exception on server accept()"
             return
         self.count += 1
         handler = http_handler(conn, addr, self, self.count)

     def decrement(self):
         self.count -= 1

class http_handler(asyncore.dispatcher):

     def __init__(self, conn, addr, server, count):
         asyncore.dispatcher.__init__(self, sock=conn)
         self.addr = addr
         self.buffer = ""
         self.time = time.time()
         self.count = count
         self.server = server

     def handle_read(self):
         rq = self.recv(1024)
         self.buffer = """HTTP/1.0 200 OK Canned Response Follows
Content-Type: text/html

<HTML>
<HEAD>
     <TITLE>Response from server</TITLE>
</HEAD>
<BODY>
<P>This is socket number %d
</BODY>
""" % self.count

     def writable(self):
         if time.time()-self.time > 10:
             return len(self.buffer) > 0
         else:
             return 0

     def handle_write(self):
         sent = self.send(self.buffer)
         self.buffer = self.buffer[sent:]
         if len(self.buffer) == 0:
             self.close()
         self.server.decrement()

server = http_server('', 8080)

asyncore.loop(timeout=4.0)
--------

regards
  Steve
-- 
Steve Holden               http://www.holdenweb.com/
Python Web Programming  http://pydish.holdenweb.com/
Holden Web LLC      +1 703 861 4237  +1 800 494 3119