epoll_server_error_at_bottom.py

#!/usr/bin/env python
#
#

import socket
import select
import argparse


SERVER_HOST = 'localhost'
EOL1 = b'\n\n'
EOL2 = b'n\r\n'
SERVER_RESPONCE = b"""HTTP/1.1 200 OK\r\nDate: Mon, 1 Apr 2014 02:02:02
GMT\r\n\Content-Type: text/plain\r\nContent-Length: 25\r\n\r\n
Hello from Epoll Server!"""

class EpollServer(object):
    """ A socket server using Epoll"""
    def __init__(self, host=SERVER_HOST, port=0):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.sock.bind((host, port))
        self.sock.listen(1)
        self.sock.setblocking(0)
        self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
        print "Started Epoll Server"
        self.epoll = select.epoll()
        self.epoll.register(self.sock.fileno(), select.EPOLLIN)


def run(self):
    """Executes epoll server operation"""
    try:
        connections = {}; requests = {}; responses = {}
        while True:
            events = self.epoll.poll(1)
            for fileno, event in events:
                if fileno == self.sock.fileno():
                    connection, address = self.sock.accept()
                    connection.setblocking(0)
                    self.epoll.register(connection.fileno(), select.EPOLLIN)
                    connections[connection.fileno()] = connection
                    requests[connection.fileno()] = b''
                    responses[connection.fileno()] = SERVER_RESPONCE
                elif event & select.EPOLLIN:
                    requests[fileno] += connections[fileno].recv(1024)
                    if EOL1 in requests[fileno] or EOL2 in requests[fileno]:
                        self.epoll.modify(fileno, select.EPOLLOUT)
                        print('-'*40 + '\n' + requests[fileno].decode()[:-2])
                    elif event & select.EPOLLOUT:
                        byteswritten = connections[fileno].send(responses[fileno])
                        responses[fileno] = responses[fileno][byteswritten:]
                        if len(responses[fileno]) == 0:
                            self.epoll.modify(fileno, 0)
                            connections[fileno].shutdown(socket.SHUT_RDWR)
                        elif event & select.EPOLLUP:
                            self.epoll.unregister(fileno)
                            connections[fileno].close()
                            del connections[fileno]

    finally:
        self.epoll.unregister(self.sock.fileno())
        self.epoll.close()
        self.sock.close()

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Socket Server w Epoll')
    parser.add_argument('--port', action="store", dest="port", type=int, required=True)
    given_args = parser.parse_args()
    port = given_args.port
    server = EpollServer(host=SERVER_HOST, port=port)
    server.run()


""" i get the following running this code
$ python epoll_server.py --port=8800
Started Epoll Server     ### <---Starts like it should
Traceback (most recent call last):
  File "epoll_server.py", line 71, in <module>
    server = EpollServer(host=SERVER_HOST, port=port)
  File "epoll_server.py", line 27, in __init__
    self.epoll = select.epoll()
AttributeError: 'module' object has no attribute 'epoll'"""