"""PCSC context singleton.
__author__ = "http://www.gemalto.com"
Copyright 2001-2010 gemalto
Author: Jean-Daniel Aussel, mailto:jean-daniel.aussel@gemalto.com
This file is part of pyscard.
pyscard is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
pyscard 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with pyscard; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
"""
from threading import RLock
from smartcard.scard import *
from smartcard.pcsc.PCSCExceptions import EstablishContextException
class PCSCContext:
"""Manage a singleton pcsc context handle."""
class __PCSCContextSingleton:
"""The actual pcsc context class as a singleton."""
def __init__( self ):
hresult, self.hcontext = SCardEstablishContext( SCARD_SCOPE_USER )
if hresult!=0:
raise EstablishContextException( 'Failed to establish context: ' + SCardGetErrorMessage(hresult) )
def getContext( self ):
return self.hcontext
# the singleton
mutex = RLock()
instance = None
def __init__( self ):
PCSCContext.mutex.acquire()
try:
if not PCSCContext.instance:
PCSCContext.instance = PCSCContext.__PCSCContextSingleton()
finally:
PCSCContext.mutex.release()
def __getattr__( self, name ):
if self.instance:
return getattr( self.instance, name )
|