# -*- coding: utf-8 -*-
# Copyright (C) 2013 Sebastian Wiesner <lunaryorn@gmail.com>
# This library 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.
# This library 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 this library; if not, write to the Free Software Foundation,
# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
"""
pyudev._ctypeslib.utils
=======================
Utilities for loading ctypeslib.
.. moduleauthor:: Anne Mulhern <amulhern@redhat.com>
"""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals
from ctypes import CDLL
from ctypes.util import find_library
def load_ctypes_library(name, signatures, error_checkers):
"""
Load library ``name`` and return a :class:`ctypes.CDLL` object for it.
:param str name: the library name
:param signatures: signatures of methods
:type signatures: dict of str * (tuple of (list of type) * type)
:param error_checkers: error checkers for methods
:type error_checkers: dict of str * ((int * ptr * arglist) -> int)
The library has errno handling enabled.
Important functions are given proper signatures and return types to support
type checking and argument conversion.
:returns: a loaded library
:rtype: ctypes.CDLL
:raises ImportError: if the library is not found
"""
library_name = find_library(name)
if not library_name:
raise ImportError('No library named %s' % name)
lib = CDLL(library_name, use_errno=True)
# Add function signatures
for funcname, signature in signatures.items():
function = getattr(lib, funcname, None)
if function:
argtypes, restype = signature
function.argtypes = argtypes
function.restype = restype
errorchecker = error_checkers.get(funcname)
if errorchecker:
function.errcheck = errorchecker
return lib