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# -*- coding: utf-8 -*-
# Id: asyncore.py,v 2.51 2000/09/07 22:29:26 rushing Exp
# Modified for hplips 2003/06/20
# Author: Sam Rushing <rushing@nightmare.com>
# ======================================================================
# Copyright 1996 by Sam Rushing
#
# All Rights Reserved
#
# Permission to use, copy, modify, and distribute this software and
# its documentation for any purpose and without fee is hereby
# granted, provided that the above copyright notice appear in all
# copies and that both that copyright notice and this permission
# notice appear in supporting documentation, and that the name of Sam
# Rushing not be used in advertising or publicity pertaining to
# distribution of the software without specific, written prior
# permission.
#
# SAM RUSHING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
# INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
# NO EVENT SHALL SAM RUSHING BE LIABLE FOR ANY SPECIAL, INDIRECT OR
# CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
# OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
# NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
# ======================================================================
#
# (c) Copyright 2003-2006 Hewlett-Packard Development Company, L.P.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Modified by: Don Welch
#
"""
Basic infrastructure for asynchronous socket service clients and servers.
There are only two ways to have a program on a single processor do "more
than one thing at a time". Multi-threaded programming is the simplest and
most popular way to do it, but there is another very different technique,
that lets you have nearly all the advantages of multi-threading, without
actually using multiple threads. it's really only practical if your program
is largely I/O bound. If your program is CPU bound, then pre-emptive
scheduled threads are probably what you really need. Network servers are
rarely CPU-bound, however.
If your operating system supports the select() system call in its I/O
library (and nearly all do), then you can use it to juggle multiple
communication channels at once; doing other work while your I/O is taking
place in the "background." Although this strategy can seem strange and
complex, especially at first, it is in many ways easier to understand and
control than multi-threaded programming. The module documented here solves
many of the difficult problems for you, making the task of building
sophisticated high-performance network servers and clients a snap.
NOTICE: This copy of asyncore has been modified from the Python Std Lib version.
"""
import select
import socket
import sys
import time
import os
from qt import *
from g import *
from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET, \
ENOTCONN, ESHUTDOWN, EINTR, EISCONN, EAGAIN
class ExitNow(Exception):
pass
channels = {}
class dispatcher(QObject):
connected = False
accepting = False
closing = False
addr = None
def __init__ (self, sock=None):
self.sock_write_notifier = None
self.sock_read_notifier = None
if sock:
self.set_socket(sock)
self.socket.setblocking(0)
self.connected = True
try:
self.addr = sock.getpeername()
except socket.error:
# The addr isn't crucial
pass
else:
self.socket = None
def add_channel(self):
global channels
channels[self._fileno] = self
self.sock_read_notifier = QSocketNotifier(self._fileno, QSocketNotifier.Read)
QObject.connect(self.sock_read_notifier, SIGNAL("activated(int)"), self.handle_read_event)
self.sock_read_notifier.setEnabled(True)
self.sock_write_notifier = QSocketNotifier(self._fileno, QSocketNotifier.Write)
QObject.connect(self.sock_write_notifier, SIGNAL("activated(int)"), self.handle_write_event)
self.sock_write_notifier.setEnabled(False)
def del_channel(self):
QObject.disconnect(self.sock_read_notifier, SIGNAL("activated(int)"), self.handle_read_event)
QObject.disconnect(self.sock_write_notifier, SIGNAL("activated(int)"), self.handle_write_event)
self.sock_write_notifier.setEnabled(False)
self.sock_read_notifier.setEnabled(False)
global channels
try:
del channels[self._fileno]
except KeyError:
pass
self._fileno = 0
def create_socket(self, family, type):
self.family_and_type = family, type
self.socket = socket.socket (family, type)
self.socket.setblocking(0)
self._fileno = self.socket.fileno()
self.add_channel()
def set_socket(self, sock):
self.socket = sock
self._fileno = sock.fileno()
self.add_channel()
def set_reuse_addr(self):
# try to re-use a server port if possible
try:
self.socket.setsockopt (
socket.SOL_SOCKET, socket.SO_REUSEADDR,
self.socket.getsockopt (socket.SOL_SOCKET,
socket.SO_REUSEADDR) | 1
)
except socket.error:
pass
# ==================================================
# socket object methods.
# ==================================================
def listen (self, num):
self.accepting = True
return self.socket.listen(num)
def bind(self, addr):
self.addr = addr
return self.socket.bind(addr)
def connect(self, address):
self.connected = False
err = self.socket.connect_ex(address)
if err in (EINPROGRESS, EALREADY, EWOULDBLOCK):
r, w, e = select.select([], [self.socket.fileno()], [], 5.0)
err = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
if err in (0, EISCONN):
self.addr = address
self.connected = True
self.handle_connect()
else:
raise socket.error, err
def accept (self):
try:
conn, addr = self.socket.accept()
return conn, addr
except socket.error, why:
if why[0] == EWOULDBLOCK:
pass
else:
raise socket.error, why
def send (self, data):
try:
result = self.socket.send(data)
except socket.error, why:
if why[0] == EWOULDBLOCK:
return 0
elif why[0] == EAGAIN:
self.sock_write_notifier.setEnabled(True)
return 0
else:
raise socket.error, why
else: # write succeeded
self.sock_write_notifier.setEnabled(False)
return result
def recv(self, buffer_size):
try:
data = self.socket.recv (buffer_size)
if not data:
# a closed connection is indicated by signaling
# a read condition, and having recv() return 0.
self.handle_close()
return ''
else:
return data
except socket.error, why:
# winsock sometimes throws ENOTCONN
if why[0] in [ECONNRESET, ENOTCONN, ESHUTDOWN]:
self.handle_close()
return ''
else:
raise socket.error, why
def close (self):
self.del_channel()
self.connected = False
self.socket.close()
# cheap inheritance, used to pass all other attribute
# references to the underlying socket object.
def __getattr__ (self, attr):
return getattr (self.socket, attr)
def handle_read_event(self):
if self.accepting:
# for an accepting socket, getting a read implies
# that we are connected
if not self.connected:
self.connected = True
self.handle_accept()
elif not self.connected:
self.handle_connect()
self.connected = True
self.handle_read()
else:
self.handle_read()
def handle_write_event(self):
# getting a write implies that we are connected
if not self.connected:
self.handle_connect()
self.connected = True
self.handle_write()
def handle_expt_event(self):
self.handle_expt()
def handle_error(self):
self.handle_close()
def handle_expt(self):
raise Error
def handle_read(self):
raise Error
def handle_write(self):
raise Error
def handle_connect(self):
pass
def handle_accept(self):
raise Error
def handle_close(self):
self.close()
def close_all():
global channels
for x in channels.values():
x.channels.close()
channels.clear()
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