Viewing file:  filesystem.py (5.13 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
import errno
import os
import os.path
import random
import shutil
import stat
import sys
from contextlib import contextmanager
from tempfile import NamedTemporaryFile
# NOTE: retrying is not annotated in typeshed as on 2017-07-17, which is
# why we ignore the type on this import.
from pip._vendor.retrying import retry # type: ignore
from pip._vendor.six import PY2
from pip._internal.utils.compat import get_path_uid
from pip._internal.utils.typing import MYPY_CHECK_RUNNING, cast
if MYPY_CHECK_RUNNING:
from typing import BinaryIO, Iterator
class NamedTemporaryFileResult(BinaryIO):
@property
def file(self):
# type: () -> BinaryIO
pass
def check_path_owner(path):
# type: (str) -> bool
# If we don't have a way to check the effective uid of this process, then
# we'll just assume that we own the directory.
if sys.platform == "win32" or not hasattr(os, "geteuid"):
return True
assert os.path.isabs(path)
previous = None
while path != previous:
if os.path.lexists(path):
# Check if path is writable by current user.
if os.geteuid() == 0:
# Special handling for root user in order to handle properly
# cases where users use sudo without -H flag.
try:
path_uid = get_path_uid(path)
except OSError:
return False
return path_uid == 0
else:
return os.access(path, os.W_OK)
else:
previous, path = path, os.path.dirname(path)
return False # assume we don't own the path
def copy2_fixed(src, dest):
# type: (str, str) -> None
"""Wrap shutil.copy2() but map errors copying socket files to
SpecialFileError as expected.
See also https://bugs.python.org/issue37700.
"""
try:
shutil.copy2(src, dest)
except (OSError, IOError):
for f in [src, dest]:
try:
is_socket_file = is_socket(f)
except OSError:
# An error has already occurred. Another error here is not
# a problem and we can ignore it.
pass
else:
if is_socket_file:
raise shutil.SpecialFileError("`%s` is a socket" % f)
raise
def is_socket(path):
# type: (str) -> bool
return stat.S_ISSOCK(os.lstat(path).st_mode)
@contextmanager
def adjacent_tmp_file(path):
# type: (str) -> Iterator[NamedTemporaryFileResult]
"""Given a path to a file, open a temp file next to it securely and ensure
it is written to disk after the context reaches its end.
"""
with NamedTemporaryFile(
delete=False,
dir=os.path.dirname(path),
prefix=os.path.basename(path),
suffix='.tmp',
) as f:
result = cast('NamedTemporaryFileResult', f)
try:
yield result
finally:
result.file.flush()
os.fsync(result.file.fileno())
_replace_retry = retry(stop_max_delay=1000, wait_fixed=250)
if PY2:
@_replace_retry
def replace(src, dest):
# type: (str, str) -> None
try:
os.rename(src, dest)
except OSError:
os.remove(dest)
os.rename(src, dest)
else:
replace = _replace_retry(os.replace)
# test_writable_dir and _test_writable_dir_win are copied from Flit,
# with the author's agreement to also place them under pip's license.
def test_writable_dir(path):
# type: (str) -> bool
"""Check if a directory is writable.
Uses os.access() on POSIX, tries creating files on Windows.
"""
# If the directory doesn't exist, find the closest parent that does.
while not os.path.isdir(path):
parent = os.path.dirname(path)
if parent == path:
break # Should never get here, but infinite loops are bad
path = parent
if os.name == 'posix':
return os.access(path, os.W_OK)
return _test_writable_dir_win(path)
def _test_writable_dir_win(path):
# type: (str) -> bool
# os.access doesn't work on Windows: http://bugs.python.org/issue2528
# and we can't use tempfile: http://bugs.python.org/issue22107
basename = 'accesstest_deleteme_fishfingers_custard_'
alphabet = 'abcdefghijklmnopqrstuvwxyz0123456789'
for i in range(10):
name = basename + ''.join(random.choice(alphabet) for _ in range(6))
file = os.path.join(path, name)
try:
fd = os.open(file, os.O_RDWR | os.O_CREAT | os.O_EXCL)
except OSError as e:
if e.errno == errno.EEXIST:
continue
if e.errno == errno.EPERM:
# This could be because there's a directory with the same name.
# But it's highly unlikely there's a directory called that,
# so we'll assume it's because the parent dir is not writable.
return False
raise
else:
os.close(fd)
os.unlink(file)
return True
# This should never be reached
raise EnvironmentError(
'Unexpected condition testing for writable directory'
)
|