Update filelock 3.12.4 (c1163ae) → 3.14.0 (8556141).

CHANGES.md

@@ -1,6 +1,7 @@
 ### 3.32.0 (2024-xx-xx xx:xx:00 UTC)
 
 * Update CacheControl 0.13.1 (783a338) to 0.14.0 (e2be0c2)
+* Update filelock 3.12.4 (c1163ae) to 3.14.0 (8556141)
 * Update idna library 3.4 (cab054c) to 3.7 (1d365e1)
 * Update Requests library 2.31.0 (8812812) to 2.32.3 (0e322af)
 * Update urllib3 2.0.7 (56f01e0) to 2.2.1 (54d6edf)

lib/filelock/__init__.py

@@ -5,6 +5,7 @@ A platform independent file lock that supports the with-statement.
    :no-value:
 
 """
+
 from __future__ import annotations
 
 import sys
@@ -32,7 +33,7 @@ else:  # pragma: win32 no cover # noqa: PLR5501
         if warnings is not None:
             warnings.warn("only soft file lock is available", stacklevel=2)
 
-if TYPE_CHECKING:  # noqa: SIM108
+if TYPE_CHECKING:
     FileLock = SoftFileLock
 else:
     #: Alias for the lock, which should be used for the current platform.
@@ -40,12 +41,12 @@ else:
 
 
 __all__ = [
-    "__version__",
+    "AcquireReturnProxy",
+    "BaseFileLock",
     "FileLock",
     "SoftFileLock",
     "Timeout",
     "UnixFileLock",
     "WindowsFileLock",
-    "BaseFileLock",
+    "__version__",
-    "AcquireReturnProxy",
 ]

lib/filelock/_api.py

@@ -9,6 +9,7 @@ from abc import ABC, abstractmethod
 from dataclasses import dataclass
 from threading import local
 from typing import TYPE_CHECKING, Any
+from weakref import WeakValueDictionary
 
 from ._error import Timeout
 
@@ -29,7 +30,7 @@ _LOGGER = logging.getLogger("filelock")
 # is not called twice when entering the with statement. If we would simply return *self*, the lock would be acquired
 # again in the *__enter__* method of the BaseFileLock, but not released again automatically. issue #37 (memory leak)
 class AcquireReturnProxy:
-    """A context aware object that will release the lock file when exiting."""
+    """A context-aware object that will release the lock file when exiting."""
 
     def __init__(self, lock: BaseFileLock) -> None:
         self.lock = lock
@@ -62,6 +63,9 @@ class FileLockContext:
     #: The mode for the lock files
     mode: int
 
+    #: Whether the lock should be blocking or not
+    blocking: bool
+
     #: The file descriptor for the *_lock_file* as it is returned by the os.open() function, not None when lock held
     lock_file_fd: int | None = None
 
@@ -76,25 +80,66 @@ class ThreadLocalFileContext(FileLockContext, local):
 class BaseFileLock(ABC, contextlib.ContextDecorator):
     """Abstract base class for a file lock object."""
 
-    def __init__(
+    _instances: WeakValueDictionary[str, BaseFileLock]
+
+    def __new__(  # noqa: PLR0913
+        cls,
+        lock_file: str | os.PathLike[str],
+        timeout: float = -1,
+        mode: int = 0o644,
+        thread_local: bool = True,  # noqa: ARG003, FBT001, FBT002
+        *,
+        blocking: bool = True,  # noqa: ARG003
+        is_singleton: bool = False,
+        **kwargs: dict[str, Any],  # capture remaining kwargs for subclasses  # noqa: ARG003
+    ) -> Self:
+        """Create a new lock object or if specified return the singleton instance for the lock file."""
+        if not is_singleton:
+            return super().__new__(cls)
+
+        instance = cls._instances.get(str(lock_file))
+        if not instance:
+            instance = super().__new__(cls)
+            cls._instances[str(lock_file)] = instance
+        elif timeout != instance.timeout or mode != instance.mode:
+            msg = "Singleton lock instances cannot be initialized with differing arguments"
+            raise ValueError(msg)
+
+        return instance  # type: ignore[return-value] # https://github.com/python/mypy/issues/15322
+
+    def __init_subclass__(cls, **kwargs: dict[str, Any]) -> None:
+        """Setup unique state for lock subclasses."""
+        super().__init_subclass__(**kwargs)
+        cls._instances = WeakValueDictionary()
+
+    def __init__(  # noqa: PLR0913
         self,
         lock_file: str | os.PathLike[str],
         timeout: float = -1,
         mode: int = 0o644,
         thread_local: bool = True,  # noqa: FBT001, FBT002
+        *,
+        blocking: bool = True,
+        is_singleton: bool = False,
     ) -> None:
         """
         Create a new lock object.
 
         :param lock_file: path to the file
-        :param timeout: default timeout when acquiring the lock, in seconds. It will be used as fallback value in
+        :param timeout: default timeout when acquiring the lock, in seconds. It will be used as fallback value in \
-        the acquire method, if no timeout value (``None``) is given. If you want to disable the timeout, set it
+            the acquire method, if no timeout value (``None``) is given. If you want to disable the timeout, set it \
-        to a negative value. A timeout of 0 means, that there is exactly one attempt to acquire the file lock.
+            to a negative value. A timeout of 0 means that there is exactly one attempt to acquire the file lock.
-        :param mode: file permissions for the lockfile.
+        :param mode: file permissions for the lockfile
-        :param thread_local: Whether this object's internal context should be thread local or not.
+        :param thread_local: Whether this object's internal context should be thread local or not. If this is set to \
-        If this is set to ``False`` then the lock will be reentrant across threads.
+            ``False`` then the lock will be reentrant across threads.
+        :param blocking: whether the lock should be blocking or not
+        :param is_singleton: If this is set to ``True`` then only one instance of this class will be created \
+            per lock file. This is useful if you want to use the lock object for reentrant locking without needing \
+            to pass the same object around.
+
         """
         self._is_thread_local = thread_local
+        self._is_singleton = is_singleton
 
         # Create the context. Note that external code should not work with the context directly and should instead use
         # properties of this class.
@@ -102,6 +147,7 @@ class BaseFileLock(ABC, contextlib.ContextDecorator):
             "lock_file": os.fspath(lock_file),
             "timeout": timeout,
             "mode": mode,
+            "blocking": blocking,
         }
         self._context: FileLockContext = (ThreadLocalFileContext if thread_local else FileLockContext)(**kwargs)
 
@@ -109,6 +155,11 @@ class BaseFileLock(ABC, contextlib.ContextDecorator):
         """:return: a flag indicating if this lock is thread local or not"""
         return self._is_thread_local
 
+    @property
+    def is_singleton(self) -> bool:
+        """:return: a flag indicating if this lock is singleton or not"""
+        return self._is_singleton
+
     @property
     def lock_file(self) -> str:
         """:return: path to the lock file"""
@@ -129,9 +180,30 @@ class BaseFileLock(ABC, contextlib.ContextDecorator):
         Change the default timeout value.
 
         :param value: the new value, in seconds
+
         """
         self._context.timeout = float(value)
 
+    @property
+    def blocking(self) -> bool:
+        """:return: whether the locking is blocking or not"""
+        return self._context.blocking
+
+    @blocking.setter
+    def blocking(self, value: bool) -> None:
+        """
+        Change the default blocking value.
+
+        :param value: the new value as bool
+
+        """
+        self._context.blocking = value
+
+    @property
+    def mode(self) -> int:
+        """:return: the file permissions for the lockfile"""
+        return self._context.mode
+
     @abstractmethod
     def _acquire(self) -> None:
         """If the file lock could be acquired, self._context.lock_file_fd holds the file descriptor of the lock file."""
@@ -165,7 +237,7 @@ class BaseFileLock(ABC, contextlib.ContextDecorator):
         poll_interval: float = 0.05,
         *,
         poll_intervall: float | None = None,
-        blocking: bool = True,
+        blocking: bool | None = None,
     ) -> AcquireReturnProxy:
         """
         Try to acquire the file lock.
@@ -202,6 +274,9 @@ class BaseFileLock(ABC, contextlib.ContextDecorator):
         if timeout is None:
             timeout = self._context.timeout
 
+        if blocking is None:
+            blocking = self._context.blocking
+
         if poll_intervall is not None:
             msg = "use poll_interval instead of poll_intervall"
             warnings.warn(msg, DeprecationWarning, stacklevel=2)
@@ -237,10 +312,11 @@ class BaseFileLock(ABC, contextlib.ContextDecorator):
 
     def release(self, force: bool = False) -> None:  # noqa: FBT001, FBT002
         """
-        Releases the file lock. Please note, that the lock is only completely released, if the lock counter is 0. Also
+        Releases the file lock. Please note, that the lock is only completely released, if the lock counter is 0.
-        note, that the lock file itself is not automatically deleted.
+        Also note, that the lock file itself is not automatically deleted.
 
         :param force: If true, the lock counter is ignored and the lock is released in every case/
+
         """
         if self.is_locked:
             self._context.lock_counter -= 1
@@ -258,6 +334,7 @@ class BaseFileLock(ABC, contextlib.ContextDecorator):
         Acquire the lock.
 
         :return: the lock object
+
         """
         self.acquire()
         return self
@@ -274,6 +351,7 @@ class BaseFileLock(ABC, contextlib.ContextDecorator):
         :param exc_type: the exception type if raised
         :param exc_value: the exception value if raised
         :param traceback: the exception traceback if raised
+
         """
         self.release()
 
@@ -283,6 +361,6 @@ class BaseFileLock(ABC, contextlib.ContextDecorator):
 
 
 __all__ = [
-    "BaseFileLock",
     "AcquireReturnProxy",
+    "BaseFileLock",
 ]

lib/filelock/_unix.py

@@ -4,6 +4,7 @@ import os
 import sys
 from contextlib import suppress
 from errno import ENOSYS
+from pathlib import Path
 from typing import cast
 
 from ._api import BaseFileLock
@@ -35,7 +36,9 @@ else:  # pragma: win32 no cover
 
         def _acquire(self) -> None:
             ensure_directory_exists(self.lock_file)
-            open_flags = os.O_RDWR | os.O_CREAT | os.O_TRUNC
+            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)
@@ -44,7 +47,7 @@ else:  # pragma: win32 no cover
             except OSError as exception:
                 os.close(fd)
                 if exception.errno == ENOSYS:  # NotImplemented error
-                    msg = "FileSystem does not appear to support flock; user SoftFileLock instead"
+                    msg = "FileSystem does not appear to support flock; use SoftFileLock instead"
                     raise NotImplementedError(msg) from exception
             else:
                 self._context.lock_file_fd = fd
@@ -60,6 +63,6 @@ else:  # pragma: win32 no cover
 
 
 __all__ = [
-    "has_fcntl",
     "UnixFileLock",
+    "has_fcntl",
 ]

lib/filelock/_util.py

@@ -10,10 +10,13 @@ from pathlib import Path
 def raise_on_not_writable_file(filename: str) -> None:
     """
     Raise an exception if attempting to open the file for writing would fail.
-    This is done so files that will never be writable can be separated from
+
-    files that are writable but currently locked
+    This is done so files that will never be writable can be separated from files that are writable but currently
+    locked.
+
     :param filename: file to check
     :raises OSError: as if the file was opened for writing.
+
     """
     try:  # use stat to do exists + can write to check without race condition
         file_stat = os.stat(filename)  # noqa: PTH116
@@ -35,13 +38,15 @@ def raise_on_not_writable_file(filename: str) -> None:
 
 def ensure_directory_exists(filename: Path | str) -> None:
     """
-    Ensure the directory containing the file exists (create it if necessary)
+    Ensure the directory containing the file exists (create it if necessary).
+
     :param filename: file.
+
     """
     Path(filename).parent.mkdir(parents=True, exist_ok=True)
 
 
 __all__ = [
-    "raise_on_not_writable_file",
     "ensure_directory_exists",
+    "raise_on_not_writable_file",
 ]

lib/filelock/version.py

@@ -1,4 +1,4 @@
 # file generated by setuptools_scm
 # don't change, don't track in version control
-__version__ = version = '3.12.4'
+__version__ = version = '3.14.0'
-__version_tuple__ = version_tuple = (3, 12, 4)
+__version_tuple__ = version_tuple = (3, 14, 0)