usr/lib/python3.6/site-packages/pyudev/_ctypeslib/_errorcheckers.py 0000644 00000006241 15173170254 0021446 0 ustar 00 # -*- 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._errorcheckers
================================
Error checkers for ctypes wrappers.
"""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals
import os
import errno
from ctypes import get_errno
ERRNO_EXCEPTIONS = {
errno.ENOMEM: MemoryError,
errno.EOVERFLOW: OverflowError,
errno.EINVAL: ValueError
}
def exception_from_errno(errnum):
"""Create an exception from ``errnum``.
``errnum`` is an integral error number.
Return an exception object appropriate to ``errnum``.
"""
exception = ERRNO_EXCEPTIONS.get(errnum)
errorstr = os.strerror(errnum)
if exception is not None:
return exception(errorstr)
else:
return EnvironmentError(errnum, errorstr)
def check_negative_errorcode(result, func, *args):
"""Error checker for funtions, which return negative error codes.
If ``result`` is smaller than ``0``, it is interpreted as negative error
code, and an appropriate exception is raised:
- ``-ENOMEM`` raises a :exc:`~exceptions.MemoryError`
- ``-EOVERFLOW`` raises a :exc:`~exceptions.OverflowError`
- all other error codes raise :exc:`~exceptions.EnvironmentError`
If result is greater or equal to ``0``, it is returned unchanged.
"""
if result < 0:
# udev returns the *negative* errno code at this point
errnum = -result
raise exception_from_errno(errnum)
else:
return result
def check_errno_on_nonzero_return(result, func, *args):
"""Error checker to check the system ``errno`` as returned by
:func:`ctypes.get_errno()`.
If ``result`` is not ``0``, an exception according to this errno is raised.
Otherwise nothing happens.
"""
if result != 0:
errnum = get_errno()
if errnum != 0:
raise exception_from_errno(errnum)
return result
def check_errno_on_null_pointer_return(result, func, *args):
"""Error checker to check the system ``errno`` as returned by
:func:`ctypes.get_errno()`.
If ``result`` is a null pointer, an exception according to this errno is
raised. Otherwise nothing happens.
"""
# pylint: disable=invalid-name
if not result:
errnum = get_errno()
if errnum != 0:
raise exception_from_errno(errnum)
return result
