swift/test/unit/common/test_splice.py
Steve Kowalik 5a06e3da3b No longer import nose
Since Python 2.7, unittest in the standard library has included mulitple
facilities for skipping tests by decorators as well as an exception.
Switch to that directly, rather than importing nose.

Change-Id: I4009033473ea24f0d0faed3670db844f40051f30
2017-11-07 15:39:25 +11:00

324 lines
10 KiB
Python

# Copyright (c) 2014 OpenStack Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
'''Tests for `swift.common.splice`'''
import os
import errno
import ctypes
import logging
import tempfile
import unittest
import contextlib
import re
import mock
import six
from swift.common.splice import splice, tee
LOGGER = logging.getLogger(__name__)
def NamedTemporaryFile():
'''Wrapper to tempfile.NamedTemporaryFile() disabling bufferring.
The wrapper is used to support Python 2 and Python 3 in the same
code base.
'''
if six.PY3:
return tempfile.NamedTemporaryFile(buffering=0)
else:
return tempfile.NamedTemporaryFile(bufsize=0)
def safe_close(fd):
'''Close a file descriptor, ignoring any exceptions'''
try:
os.close(fd)
except Exception:
LOGGER.exception('Error while closing FD')
@contextlib.contextmanager
def pipe():
'''Context-manager providing 2 ends of a pipe, closing them at exit'''
fds = os.pipe()
try:
yield fds
finally:
safe_close(fds[0])
safe_close(fds[1])
class TestSplice(unittest.TestCase):
'''Tests for `splice`'''
def setUp(self):
if not splice.available:
raise unittest.SkipTest('splice not available')
def test_flags(self):
'''Test flag attribute availability'''
self.assertTrue(hasattr(splice, 'SPLICE_F_MOVE'))
self.assertTrue(hasattr(splice, 'SPLICE_F_NONBLOCK'))
self.assertTrue(hasattr(splice, 'SPLICE_F_MORE'))
self.assertTrue(hasattr(splice, 'SPLICE_F_GIFT'))
@mock.patch('swift.common.splice.splice._c_splice', None)
def test_available(self):
'''Test `available` attribute correctness'''
self.assertFalse(splice.available)
def test_splice_pipe_to_pipe(self):
'''Test `splice` from a pipe to a pipe'''
with pipe() as (p1a, p1b):
with pipe() as (p2a, p2b):
os.write(p1b, b'abcdef')
res = splice(p1a, None, p2b, None, 3, 0)
self.assertEqual(res, (3, None, None))
self.assertEqual(os.read(p2a, 3), b'abc')
self.assertEqual(os.read(p1a, 3), b'def')
def test_splice_file_to_pipe(self):
'''Test `splice` from a file to a pipe'''
with NamedTemporaryFile() as fd:
with pipe() as (pa, pb):
fd.write(b'abcdef')
fd.seek(0, os.SEEK_SET)
res = splice(fd, None, pb, None, 3, 0)
self.assertEqual(res, (3, None, None))
# `fd.tell()` isn't updated...
self.assertEqual(os.lseek(fd.fileno(), 0, os.SEEK_CUR), 3)
fd.seek(0, os.SEEK_SET)
res = splice(fd, 3, pb, None, 3, 0)
self.assertEqual(res, (3, 6, None))
self.assertEqual(os.lseek(fd.fileno(), 0, os.SEEK_CUR), 0)
self.assertEqual(os.read(pa, 6), b'abcdef')
def test_splice_pipe_to_file(self):
'''Test `splice` from a pipe to a file'''
with NamedTemporaryFile() as fd:
with pipe() as (pa, pb):
os.write(pb, b'abcdef')
res = splice(pa, None, fd, None, 3, 0)
self.assertEqual(res, (3, None, None))
self.assertEqual(fd.tell(), 3)
fd.seek(0, os.SEEK_SET)
res = splice(pa, None, fd, 3, 3, 0)
self.assertEqual(res, (3, None, 6))
self.assertEqual(fd.tell(), 0)
self.assertEqual(fd.read(6), b'abcdef')
@mock.patch.object(splice, '_c_splice')
def test_fileno(self, mock_splice):
'''Test handling of file-descriptors'''
splice(1, None, 2, None, 3, 0)
self.assertEqual(mock_splice.call_args,
((1, None, 2, None, 3, 0), {}))
mock_splice.reset_mock()
with open('/dev/zero', 'r') as fd:
splice(fd, None, fd, None, 3, 0)
self.assertEqual(mock_splice.call_args,
((fd.fileno(), None, fd.fileno(), None, 3, 0),
{}))
@mock.patch.object(splice, '_c_splice')
def test_flags_list(self, mock_splice):
'''Test handling of flag lists'''
splice(1, None, 2, None, 3,
[splice.SPLICE_F_MOVE, splice.SPLICE_F_NONBLOCK])
flags = splice.SPLICE_F_MOVE | splice.SPLICE_F_NONBLOCK
self.assertEqual(mock_splice.call_args,
((1, None, 2, None, 3, flags), {}))
mock_splice.reset_mock()
splice(1, None, 2, None, 3, [])
self.assertEqual(mock_splice.call_args,
((1, None, 2, None, 3, 0), {}))
def test_errno(self):
'''Test handling of failures'''
# Invoke EBADF by using a read-only FD as fd_out
with open('/dev/null', 'r') as fd:
err = errno.EBADF
msg = r'\[Errno %d\] splice: %s' % (err, os.strerror(err))
try:
splice(fd, None, fd, None, 3, 0)
except IOError as e:
self.assertTrue(re.match(msg, str(e)))
else:
self.fail('Expected IOError was not raised')
self.assertEqual(ctypes.get_errno(), 0)
@mock.patch('swift.common.splice.splice._c_splice', None)
def test_unavailable(self):
'''Test exception when unavailable'''
self.assertRaises(EnvironmentError, splice, 1, None, 2, None, 2, 0)
def test_unavailable_in_libc(self):
'''Test `available` attribute when `libc` has no `splice` support'''
class LibC(object):
'''A fake `libc` object tracking `splice` attribute access'''
def __init__(self):
self.splice_retrieved = False
@property
def splice(self):
self.splice_retrieved = True
raise AttributeError
libc = LibC()
mock_cdll = mock.Mock(return_value=libc)
with mock.patch('ctypes.CDLL', new=mock_cdll):
# Force re-construction of a `Splice` instance
# Something you're not supposed to do in actual code
new_splice = type(splice)()
self.assertFalse(new_splice.available)
libc_name = ctypes.util.find_library('c')
mock_cdll.assert_called_once_with(libc_name, use_errno=True)
self.assertTrue(libc.splice_retrieved)
class TestTee(unittest.TestCase):
'''Tests for `tee`'''
def setUp(self):
if not tee.available:
raise unittest.SkipTest('tee not available')
@mock.patch('swift.common.splice.tee._c_tee', None)
def test_available(self):
'''Test `available` attribute correctness'''
self.assertFalse(tee.available)
def test_tee_pipe_to_pipe(self):
'''Test `tee` from a pipe to a pipe'''
with pipe() as (p1a, p1b):
with pipe() as (p2a, p2b):
os.write(p1b, b'abcdef')
res = tee(p1a, p2b, 3, 0)
self.assertEqual(res, 3)
self.assertEqual(os.read(p2a, 3), b'abc')
self.assertEqual(os.read(p1a, 6), b'abcdef')
@mock.patch.object(tee, '_c_tee')
def test_fileno(self, mock_tee):
'''Test handling of file-descriptors'''
with pipe() as (pa, pb):
tee(pa, pb, 3, 0)
self.assertEqual(mock_tee.call_args, ((pa, pb, 3, 0), {}))
mock_tee.reset_mock()
tee(os.fdopen(pa, 'r'), os.fdopen(pb, 'w'), 3, 0)
self.assertEqual(mock_tee.call_args, ((pa, pb, 3, 0), {}))
@mock.patch.object(tee, '_c_tee')
def test_flags_list(self, mock_tee):
'''Test handling of flag lists'''
tee(1, 2, 3, [splice.SPLICE_F_MOVE | splice.SPLICE_F_NONBLOCK])
flags = splice.SPLICE_F_MOVE | splice.SPLICE_F_NONBLOCK
self.assertEqual(mock_tee.call_args, ((1, 2, 3, flags), {}))
mock_tee.reset_mock()
tee(1, 2, 3, [])
self.assertEqual(mock_tee.call_args, ((1, 2, 3, 0), {}))
def test_errno(self):
'''Test handling of failures'''
# Invoke EBADF by using a read-only FD as fd_out
with open('/dev/null', 'r') as fd:
err = errno.EBADF
msg = r'\[Errno %d\] tee: %s' % (err, os.strerror(err))
try:
tee(fd, fd, 3, 0)
except IOError as e:
self.assertTrue(re.match(msg, str(e)))
else:
self.fail('Expected IOError was not raised')
self.assertEqual(ctypes.get_errno(), 0)
@mock.patch('swift.common.splice.tee._c_tee', None)
def test_unavailable(self):
'''Test exception when unavailable'''
self.assertRaises(EnvironmentError, tee, 1, 2, 2, 0)
def test_unavailable_in_libc(self):
'''Test `available` attribute when `libc` has no `tee` support'''
class LibC(object):
'''A fake `libc` object tracking `tee` attribute access'''
def __init__(self):
self.tee_retrieved = False
@property
def tee(self):
self.tee_retrieved = True
raise AttributeError
libc = LibC()
mock_cdll = mock.Mock(return_value=libc)
with mock.patch('ctypes.CDLL', new=mock_cdll):
# Force re-construction of a `Tee` instance
# Something you're not supposed to do in actual code
new_tee = type(tee)()
self.assertFalse(new_tee.available)
libc_name = ctypes.util.find_library('c')
mock_cdll.assert_called_once_with(libc_name, use_errno=True)
self.assertTrue(libc.tee_retrieved)