updates
This commit is contained in:
@@ -0,0 +1,65 @@
|
||||
from __future__ import annotations
|
||||
|
||||
import os
|
||||
import sys
|
||||
from contextlib import suppress
|
||||
from errno import EACCES
|
||||
from pathlib import Path
|
||||
from typing import cast
|
||||
|
||||
from ._api import BaseFileLock
|
||||
from ._util import ensure_directory_exists, raise_on_not_writable_file
|
||||
|
||||
if sys.platform == "win32": # pragma: win32 cover
|
||||
import msvcrt
|
||||
|
||||
class WindowsFileLock(BaseFileLock):
|
||||
"""Uses the :func:`msvcrt.locking` function to hard lock the lock file on Windows systems."""
|
||||
|
||||
def _acquire(self) -> None:
|
||||
raise_on_not_writable_file(self.lock_file)
|
||||
ensure_directory_exists(self.lock_file)
|
||||
flags = (
|
||||
os.O_RDWR # open for read and write
|
||||
| os.O_CREAT # create file if not exists
|
||||
| os.O_TRUNC # truncate file if not empty
|
||||
)
|
||||
try:
|
||||
fd = os.open(self.lock_file, flags, self._context.mode)
|
||||
except OSError as exception:
|
||||
if exception.errno != EACCES: # has no access to this lock
|
||||
raise
|
||||
else:
|
||||
try:
|
||||
msvcrt.locking(fd, msvcrt.LK_NBLCK, 1)
|
||||
except OSError as exception:
|
||||
os.close(fd) # close file first
|
||||
if exception.errno != EACCES: # file is already locked
|
||||
raise
|
||||
else:
|
||||
self._context.lock_file_fd = fd
|
||||
|
||||
def _release(self) -> None:
|
||||
fd = cast("int", self._context.lock_file_fd)
|
||||
self._context.lock_file_fd = None
|
||||
msvcrt.locking(fd, msvcrt.LK_UNLCK, 1)
|
||||
os.close(fd)
|
||||
|
||||
with suppress(OSError): # Probably another instance of the application hat acquired the file lock.
|
||||
Path(self.lock_file).unlink()
|
||||
|
||||
else: # pragma: win32 no cover
|
||||
|
||||
class WindowsFileLock(BaseFileLock):
|
||||
"""Uses the :func:`msvcrt.locking` function to hard lock the lock file on Windows systems."""
|
||||
|
||||
def _acquire(self) -> None:
|
||||
raise NotImplementedError
|
||||
|
||||
def _release(self) -> None:
|
||||
raise NotImplementedError
|
||||
|
||||
|
||||
__all__ = [
|
||||
"WindowsFileLock",
|
||||
]
|
||||
Reference in New Issue
Block a user