mirror of
https://github.com/SickGear/SickGear.git
synced 2024-11-27 15:13:38 +00:00
68 lines
2.2 KiB
Python
68 lines
2.2 KiB
Python
from __future__ import annotations
|
|
|
|
import os
|
|
import sys
|
|
from contextlib import suppress
|
|
from errno import ENOSYS
|
|
from pathlib import Path
|
|
from typing import cast
|
|
|
|
from ._api import BaseFileLock
|
|
from ._util import ensure_directory_exists
|
|
|
|
#: a flag to indicate if the fcntl API is available
|
|
has_fcntl = False
|
|
if sys.platform == "win32": # pragma: win32 cover
|
|
|
|
class UnixFileLock(BaseFileLock):
|
|
"""Uses the :func:`fcntl.flock` to hard lock the lock file on unix systems."""
|
|
|
|
def _acquire(self) -> None:
|
|
raise NotImplementedError
|
|
|
|
def _release(self) -> None:
|
|
raise NotImplementedError
|
|
|
|
else: # pragma: win32 no cover
|
|
try:
|
|
import fcntl
|
|
except ImportError:
|
|
pass
|
|
else:
|
|
has_fcntl = True
|
|
|
|
class UnixFileLock(BaseFileLock):
|
|
"""Uses the :func:`fcntl.flock` to hard lock the lock file on unix systems."""
|
|
|
|
def _acquire(self) -> None:
|
|
ensure_directory_exists(self.lock_file)
|
|
open_flags = os.O_RDWR | os.O_TRUNC
|
|
if not Path(self.lock_file).exists():
|
|
open_flags |= os.O_CREAT
|
|
fd = os.open(self.lock_file, open_flags, self._context.mode)
|
|
with suppress(PermissionError): # This locked is not owned by this UID
|
|
os.fchmod(fd, self._context.mode)
|
|
try:
|
|
fcntl.flock(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
|
|
except OSError as exception:
|
|
os.close(fd)
|
|
if exception.errno == ENOSYS: # NotImplemented error
|
|
msg = "FileSystem does not appear to support flock; use SoftFileLock instead"
|
|
raise NotImplementedError(msg) from exception
|
|
else:
|
|
self._context.lock_file_fd = fd
|
|
|
|
def _release(self) -> None:
|
|
# Do not remove the lockfile:
|
|
# https://github.com/tox-dev/py-filelock/issues/31
|
|
# https://stackoverflow.com/questions/17708885/flock-removing-locked-file-without-race-condition
|
|
fd = cast(int, self._context.lock_file_fd)
|
|
self._context.lock_file_fd = None
|
|
fcntl.flock(fd, fcntl.LOCK_UN)
|
|
os.close(fd)
|
|
|
|
|
|
__all__ = [
|
|
"UnixFileLock",
|
|
"has_fcntl",
|
|
]
|