Current File : //usr/share/system-config-printer/asyncconn.py
#!/usr/bin/python3
## Copyright (C) 2007, 2008, 2009, 2010, 2012, 2013 Red Hat, Inc.
## Copyright (C) 2008 Novell, Inc.
## Authors: Tim Waugh <twaugh@redhat.com>, Vincent Untz
## 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
import cups
import os
from debug import *
import debug
######
###### A class to keep track of what we're trying to achieve in order
###### to display that to the user if authentication is required.
######
class SemanticOperations(object):
def __init__ (self):
self._operation_stack = []
def _begin_operation (self, operation):
self._operation_stack.append (operation)
def _end_operation (self):
self._operation_stack.pop ()
def current_operation (self):
try:
return self._operation_stack[0]
except IndexError:
return None
######
###### Destructible method call. Required so that all references can
###### be dropped when an asynchronous method call is destroyed.
######
class _AsyncMethodCall:
def __init__ (self, fn, reply_handler, error_handler, auth_handler):
self._fn = fn
self._reply_handler = reply_handler
self._error_handler = error_handler
self._auth_handler = auth_handler
self._destroyed = False
debugprint ("+%s" % self)
def __del__ (self):
debugprint ("-%s" % self)
def destroy (self):
if self._destroyed:
return
debugprint ("DESTROY: %s" % self)
self._destroyed = True
self._reply_handler = None
self._error_handler = None
self._auth_handler = None
self._reply_data = None
self._error_data = None
self._auth_data = None
def run (self, *args, **kwds):
self._reply_data = kwds.get ('reply_handler')
self._error_data = kwds.get ('error_handler')
self._auth_data = kwds.get ('auth_handler')
kwds['reply_handler'] = self.reply_handler
kwds['error_handler'] = self.error_handler
kwds['auth_handler'] = self.auth_handler
debugprint ("%s: calling %s" % (self, self._fn))
self._fn (*args, **kwds)
def reply_handler (self, *args):
if not self._destroyed:
debugprint ("%s: to reply_handler at %s" % (self,
self._reply_handler))
self._reply_handler (self, self._reply_data, *args)
def error_handler (self, *args):
if not self._destroyed:
debugprint ("%s: to error_handler at %s" % (self,
self._error_handler))
self._error_handler (self, self._error_data, *args)
def auth_handler (self, *args):
if not self._destroyed:
debugprint ("%s: to auth_handler at %s" % (self,
self._auth_handler))
self._auth_handler (self, self.auth_data, *args)
######
###### An asynchronous libcups API using IPP or PolicyKit as
###### appropriate.
######
class Connection(SemanticOperations):
def __init__ (self, reply_handler=None, error_handler=None,
auth_handler=None, host=None, port=None, encryption=None,
parent=None, try_as_root=True, prompt_allowed=True):
super (Connection, self).__init__ ()
self._destroyed = False
# Decide whether to use direct IPP or PolicyKit.
if host is None:
host = cups.getServer()
use_pk = ((host.startswith ('/') or host == 'localhost') and
os.getuid () != 0)
def subst_reply_handler (conn, reply):
self._subst_reply_handler (None, reply_handler, reply)
def subst_error_handler (conn, exc):
self._subst_error_handler (None, error_handler, exc)
def subst_auth_handler (prompt, conn, method, resource):
self._subst_auth_handler (None, auth_handler, prompt, method, resource)
if use_pk and try_as_root:
debugprint ("Using polkit-1 connection class")
import asyncpk1
c = asyncpk1.PK1Connection (reply_handler=subst_reply_handler,
error_handler=subst_error_handler,
host=host, port=port,
encryption=encryption,
parent=parent)
self._conn = c
else:
debugprint ("Using IPP connection class")
import asyncipp
c = asyncipp.IPPAuthConnection (reply_handler=subst_reply_handler,
error_handler=subst_error_handler,
auth_handler=subst_auth_handler,
host=host, port=port,
encryption=encryption,
parent=parent,
try_as_root=try_as_root,
prompt_allowed=prompt_allowed,
semantic=self)
self._conn = c
methodtype = type (self._conn.getPrinters)
instancemethodtype = type (self._conn.getDevices)
bindings = []
for fname in dir (self._conn):
if fname.startswith ('_'):
continue
fn = getattr (self._conn, fname)
if type (fn) != methodtype and type (fn) != instancemethodtype:
continue
if not hasattr (self, fname):
setattr (self, fname, self._make_binding (fn))
bindings.append (fname)
self._bindings = bindings
self._methodcalls = []
debugprint ("+%s" % self)
def __del__ (self):
debug.debugprint ("-%s" % self)
def destroy (self):
debugprint ("DESTROY: %s" % self)
self._destroyed = True
try:
self._conn.destroy ()
except AttributeError:
pass
for methodcall in self._methodcalls:
methodcall.destroy ()
for binding in self._bindings:
delattr (self, binding)
def _make_binding (self, fn):
return lambda *args, **kwds: self._call_function (fn, *args, **kwds)
def _call_function (self, fn, *args, **kwds):
methodcall = _AsyncMethodCall (fn,
self._subst_reply_handler,
self._subst_error_handler,
self._subst_auth_handler)
self._methodcalls.append (methodcall)
methodcall.run (*args, **kwds)
def _subst_reply_handler (self, methodcall, reply_handler, *args):
if methodcall:
methodcall.destroy ()
i = self._methodcalls.index (methodcall)
del self._methodcalls[i]
args = args[1:]
if reply_handler and not self._destroyed:
debugprint ("%s: chaining up to %s" % (self, reply_handler))
reply_handler (self, *args)
def _subst_error_handler (self, methodcall, error_handler, *args):
if methodcall:
methodcall.destroy ()
i = self._methodcalls.index (methodcall)
del self._methodcalls[i]
args = args[1:]
if error_handler and not self._destroyed:
debugprint ("%s: chaining up to %s" % (self, error_handler))
error_handler (self, *args)
def _subst_auth_handler (self, methodcall, auth_handler, prompt, method, resource):
if methodcall:
methodcall.destroy ()
i = self._methodcalls.index (methodcall)
del self._methodcalls[i]
if auth_handler and not self._destroyed:
debugprint ("%s: chaining up to %s" % (self, auth_handler))
auth_handler (prompt, self, method, resource)
def set_auth_info (self, password):
"""Call this from your auth_handler function."""
self.thread.set_auth_info (password)
if __name__ == "__main__":
# Demo
from gi.repository import GObject
set_debugging (True)
class Test:
def __init__ (self, quit):
self._conn = Connection ()
self._quit = quit
debugprint ("+%s" % self)
def __del__ (self):
debug.debugprint ("-%s" % self)
def destroy (self):
debugprint ("DESTROY: %s" % self)
self._conn.destroy ()
if self._quit:
loop.quit ()
def getDevices (self):
self._conn.getDevices (reply_handler=self.getDevices_reply,
error_handler=self.getDevices_error)
def getDevices_reply (self, conn, result):
print (conn, result)
self.destroy ()
def getDevices_error (self, conn, exc):
print (repr (exc))
self.destroy ()
t = Test (False)
loop = GObject.MainLoop ()
t.getDevices ()
t.destroy ()
t = Test (True)
t.getDevices ()
loop.run ()
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