Merge branch 'feature/UpdateFilelock' into dev

This commit is contained in:
JackDandy 2023-05-05 15:08:35 +01:00
commit cc007da2ee
8 changed files with 126 additions and 67 deletions

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@ -5,7 +5,7 @@
* Update attr 22.2.0 (a9960de) to 22.2.0 (683d056) * Update attr 22.2.0 (a9960de) to 22.2.0 (683d056)
* Update diskcache 5.4.0 (1cb1425) to 5.6.1 (4d30686) * Update diskcache 5.4.0 (1cb1425) to 5.6.1 (4d30686)
* Update feedparser 6.0.10 (5fcb3ae) to 6.0.10 (6d032b8) * Update feedparser 6.0.10 (5fcb3ae) to 6.0.10 (6d032b8)
* Update filelock 3.9.0 (ce3e891) to 3.11.0 (d3241b9) * Update filelock 3.9.0 (ce3e891) to 3.12.0 (b4713c9)
* Update Msgpack 1.0.4 (b5acfd5) to 1.0.5 (0516c2c) * Update Msgpack 1.0.4 (b5acfd5) to 1.0.5 (0516c2c)
* Update Pytvmaze library 2.0.8 (16ed096) to 2.0.8 (81888a5) * Update Pytvmaze library 2.0.8 (16ed096) to 2.0.8 (81888a5)
* Update Requests library 2.28.1 (ec553c2) to 2.29.0 (87d63de) * Update Requests library 2.28.1 (ec553c2) to 2.29.0 (87d63de)
@ -27,6 +27,7 @@
[develop changelog] [develop changelog]
* Update filelock 3.9.0 (ce3e891) to 3.11.0 (d3241b9)
* Fix tv test to init recently added ReleaseMap to scene_exceptions refactor * Fix tv test to init recently added ReleaseMap to scene_exceptions refactor
* Fix double use of var `result` overwrites the return value and causes an error in _parse_custom_exceptions * Fix double use of var `result` overwrites the return value and causes an error in _parse_custom_exceptions
* Fix name_parser_tests and webapi_tests * Fix name_parser_tests and webapi_tests

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@ -32,11 +32,10 @@ else: # pragma: win32 no cover
if warnings is not None: if warnings is not None:
warnings.warn("only soft file lock is available", stacklevel=2) warnings.warn("only soft file lock is available", stacklevel=2)
#: Alias for the lock, which should be used for the current platform. On Windows, this is an alias for
# :class:`WindowsFileLock`, on Unix for :class:`UnixFileLock` and otherwise for :class:`SoftFileLock`.
if TYPE_CHECKING: if TYPE_CHECKING:
FileLock = SoftFileLock FileLock = SoftFileLock
else: else:
#: Alias for the lock, which should be used for the current platform.
FileLock = _FileLock FileLock = _FileLock

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@ -6,6 +6,7 @@ import os
import time import time
import warnings import warnings
from abc import ABC, abstractmethod from abc import ABC, abstractmethod
from dataclasses import dataclass
from threading import local from threading import local
from types import TracebackType from types import TracebackType
from typing import Any from typing import Any
@ -36,7 +37,38 @@ class AcquireReturnProxy:
self.lock.release() self.lock.release()
class BaseFileLock(ABC, contextlib.ContextDecorator, local): @dataclass
class FileLockContext:
"""
A dataclass which holds the context for a ``BaseFileLock`` object.
"""
# The context is held in a separate class to allow optional use of thread local storage via the
# ThreadLocalFileContext class.
#: The path to the lock file.
lock_file: str
#: The default timeout value.
timeout: float
#: The mode for the lock files
mode: int
#: 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
#: The lock counter is used for implementing the nested locking mechanism.
lock_counter: int = 0 # When the lock is acquired is increased and the lock is only released, when this value is 0
class ThreadLocalFileContext(FileLockContext, local):
"""
A thread local version of the ``FileLockContext`` class.
"""
class BaseFileLock(ABC, contextlib.ContextDecorator):
"""Abstract base class for a file lock object.""" """Abstract base class for a file lock object."""
def __init__( def __init__(
@ -44,6 +76,7 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
lock_file: str | os.PathLike[Any], lock_file: str | os.PathLike[Any],
timeout: float = -1, timeout: float = -1,
mode: int = 0o644, mode: int = 0o644,
thread_local: bool = True,
) -> None: ) -> None:
""" """
Create a new lock object. Create a new lock object.
@ -52,29 +85,29 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
: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.
If this is set to ``False`` then the lock will be reentrant across threads.
""" """
# The path to the lock file. self._is_thread_local = thread_local
self._lock_file: str = os.fspath(lock_file)
# The file descriptor for the *_lock_file* as it is returned by the os.open() function. # Create the context. Note that external code should not work with the context directly and should instead use
# This file lock is only NOT None, if the object currently holds the lock. # properties of this class.
self._lock_file_fd: int | None = None kwargs: dict[str, Any] = {
"lock_file": os.fspath(lock_file),
"timeout": timeout,
"mode": mode,
}
self._context: FileLockContext = (ThreadLocalFileContext if thread_local else FileLockContext)(**kwargs)
# The default timeout value. def is_thread_local(self) -> bool:
self._timeout: float = timeout """:return: a flag indicating if this lock is thread local or not"""
return self._is_thread_local
# The mode for the lock files
self._mode: int = mode
# The lock counter is used for implementing the nested locking mechanism. Whenever the lock is acquired, the
# counter is increased and the lock is only released, when this value is 0 again.
self._lock_counter: int = 0
@property @property
def lock_file(self) -> str: def lock_file(self) -> str:
""":return: path to the lock file""" """:return: path to the lock file"""
return self._lock_file return self._context.lock_file
@property @property
def timeout(self) -> float: def timeout(self) -> float:
@ -83,7 +116,7 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
.. versionadded:: 2.0.0 .. versionadded:: 2.0.0
""" """
return self._timeout return self._context.timeout
@timeout.setter @timeout.setter
def timeout(self, value: float | str) -> None: def timeout(self, value: float | str) -> None:
@ -92,16 +125,16 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
:param value: the new value, in seconds :param value: the new value, in seconds
""" """
self._timeout = float(value) self._context.timeout = float(value)
@abstractmethod @abstractmethod
def _acquire(self) -> None: def _acquire(self) -> None:
"""If the file lock could be acquired, self._lock_file_fd holds the file descriptor of the lock file.""" """If the file lock could be acquired, self._context.lock_file_fd holds the file descriptor of the lock file."""
raise NotImplementedError raise NotImplementedError
@abstractmethod @abstractmethod
def _release(self) -> None: def _release(self) -> None:
"""Releases the lock and sets self._lock_file_fd to None.""" """Releases the lock and sets self._context.lock_file_fd to None."""
raise NotImplementedError raise NotImplementedError
@property @property
@ -114,7 +147,14 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
This was previously a method and is now a property. This was previously a method and is now a property.
""" """
return self._lock_file_fd is not None return self._context.lock_file_fd is not None
@property
def lock_counter(self) -> int:
"""
:return: The number of times this lock has been acquired (but not yet released).
"""
return self._context.lock_counter
def acquire( def acquire(
self, self,
@ -132,7 +172,7 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
:param poll_interval: interval of trying to acquire the lock file :param poll_interval: interval of trying to acquire the lock file
:param poll_intervall: deprecated, kept for backwards compatibility, use ``poll_interval`` instead :param poll_intervall: deprecated, kept for backwards compatibility, use ``poll_interval`` instead
:param blocking: defaults to True. If False, function will return immediately if it cannot obtain a lock on the :param blocking: defaults to True. If False, function will return immediately if it cannot obtain a lock on the
first attempt. Otherwise this method will block until the timeout expires or the lock is acquired. first attempt. Otherwise, this method will block until the timeout expires or the lock is acquired.
:raises Timeout: if fails to acquire lock within the timeout period :raises Timeout: if fails to acquire lock within the timeout period
:return: a context object that will unlock the file when the context is exited :return: a context object that will unlock the file when the context is exited
@ -157,7 +197,7 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
""" """
# Use the default timeout, if no timeout is provided. # Use the default timeout, if no timeout is provided.
if timeout is None: if timeout is None:
timeout = self.timeout timeout = self._context.timeout
if poll_intervall is not None: if poll_intervall is not None:
msg = "use poll_interval instead of poll_intervall" msg = "use poll_interval instead of poll_intervall"
@ -165,10 +205,10 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
poll_interval = poll_intervall poll_interval = poll_intervall
# Increment the number right at the beginning. We can still undo it, if something fails. # Increment the number right at the beginning. We can still undo it, if something fails.
self._lock_counter += 1 self._context.lock_counter += 1
lock_id = id(self) lock_id = id(self)
lock_filename = self._lock_file lock_filename = self.lock_file
start_time = time.perf_counter() start_time = time.perf_counter()
try: try:
while True: while True:
@ -180,16 +220,16 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
break break
elif blocking is False: elif blocking is False:
_LOGGER.debug("Failed to immediately acquire lock %s on %s", lock_id, lock_filename) _LOGGER.debug("Failed to immediately acquire lock %s on %s", lock_id, lock_filename)
raise Timeout(self._lock_file) raise Timeout(lock_filename)
elif 0 <= timeout < time.perf_counter() - start_time: elif 0 <= timeout < time.perf_counter() - start_time:
_LOGGER.debug("Timeout on acquiring lock %s on %s", lock_id, lock_filename) _LOGGER.debug("Timeout on acquiring lock %s on %s", lock_id, lock_filename)
raise Timeout(self._lock_file) raise Timeout(lock_filename)
else: else:
msg = "Lock %s not acquired on %s, waiting %s seconds ..." msg = "Lock %s not acquired on %s, waiting %s seconds ..."
_LOGGER.debug(msg, lock_id, lock_filename, poll_interval) _LOGGER.debug(msg, lock_id, lock_filename, poll_interval)
time.sleep(poll_interval) time.sleep(poll_interval)
except BaseException: # Something did go wrong, so decrement the counter. except BaseException: # Something did go wrong, so decrement the counter.
self._lock_counter = max(0, self._lock_counter - 1) self._context.lock_counter = max(0, self._context.lock_counter - 1)
raise raise
return AcquireReturnProxy(lock=self) return AcquireReturnProxy(lock=self)
@ -201,14 +241,14 @@ class BaseFileLock(ABC, contextlib.ContextDecorator, local):
:param force: If true, the lock counter is ignored and the lock is released in every case/ :param force: If true, the lock counter is ignored and the lock is released in every case/
""" """
if self.is_locked: if self.is_locked:
self._lock_counter -= 1 self._context.lock_counter -= 1
if self._lock_counter == 0 or force: if self._context.lock_counter == 0 or force:
lock_id, lock_filename = id(self), self._lock_file lock_id, lock_filename = id(self), self.lock_file
_LOGGER.debug("Attempting to release lock %s on %s", lock_id, lock_filename) _LOGGER.debug("Attempting to release lock %s on %s", lock_id, lock_filename)
self._release() self._release()
self._lock_counter = 0 self._context.lock_counter = 0
_LOGGER.debug("Lock %s released on %s", lock_id, lock_filename) _LOGGER.debug("Lock %s released on %s", lock_id, lock_filename)
def __enter__(self) -> BaseFileLock: def __enter__(self) -> BaseFileLock:

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@ -5,14 +5,14 @@ import sys
from errno import EACCES, EEXIST from errno import EACCES, EEXIST
from ._api import BaseFileLock from ._api import BaseFileLock
from ._util import raise_on_exist_ro_file from ._util import raise_on_not_writable_file
class SoftFileLock(BaseFileLock): class SoftFileLock(BaseFileLock):
"""Simply watches the existence of the lock file.""" """Simply watches the existence of the lock file."""
def _acquire(self) -> None: def _acquire(self) -> None:
raise_on_exist_ro_file(self._lock_file) raise_on_not_writable_file(self.lock_file)
# first check for exists and read-only mode as the open will mask this case as EEXIST # first check for exists and read-only mode as the open will mask this case as EEXIST
flags = ( flags = (
os.O_WRONLY # open for writing only os.O_WRONLY # open for writing only
@ -21,7 +21,7 @@ class SoftFileLock(BaseFileLock):
| os.O_TRUNC # truncate the file to zero byte | os.O_TRUNC # truncate the file to zero byte
) )
try: try:
file_handler = os.open(self._lock_file, flags, self._mode) file_handler = os.open(self.lock_file, flags, self._context.mode)
except OSError as exception: # re-raise unless expected exception except OSError as exception: # re-raise unless expected exception
if not ( if not (
exception.errno == EEXIST # lock already exist exception.errno == EEXIST # lock already exist
@ -29,13 +29,13 @@ class SoftFileLock(BaseFileLock):
): # pragma: win32 no cover ): # pragma: win32 no cover
raise raise
else: else:
self._lock_file_fd = file_handler self._context.lock_file_fd = file_handler
def _release(self) -> None: def _release(self) -> None:
os.close(self._lock_file_fd) # type: ignore # the lock file is definitely not None os.close(self._context.lock_file_fd) # type: ignore # the lock file is definitely not None
self._lock_file_fd = None self._context.lock_file_fd = None
try: try:
os.remove(self._lock_file) os.remove(self.lock_file)
except OSError: # the file is already deleted and that's what we want except OSError: # the file is already deleted and that's what we want
pass pass

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@ -33,9 +33,9 @@ else: # pragma: win32 no cover
def _acquire(self) -> None: def _acquire(self) -> None:
open_flags = os.O_RDWR | os.O_CREAT | os.O_TRUNC open_flags = os.O_RDWR | os.O_CREAT | os.O_TRUNC
fd = os.open(self._lock_file, open_flags, self._mode) fd = os.open(self.lock_file, open_flags, self._context.mode)
try: try:
os.fchmod(fd, self._mode) os.fchmod(fd, self._context.mode)
except PermissionError: except PermissionError:
pass # This locked is not owned by this UID pass # This locked is not owned by this UID
try: try:
@ -45,14 +45,14 @@ else: # pragma: win32 no cover
if exception.errno == ENOSYS: # NotImplemented error if exception.errno == ENOSYS: # NotImplemented error
raise NotImplementedError("FileSystem does not appear to support flock; user SoftFileLock instead") raise NotImplementedError("FileSystem does not appear to support flock; user SoftFileLock instead")
else: else:
self._lock_file_fd = fd self._context.lock_file_fd = fd
def _release(self) -> None: def _release(self) -> None:
# Do not remove the lockfile: # Do not remove the lockfile:
# https://github.com/tox-dev/py-filelock/issues/31 # https://github.com/tox-dev/py-filelock/issues/31
# https://stackoverflow.com/questions/17708885/flock-removing-locked-file-without-race-condition # https://stackoverflow.com/questions/17708885/flock-removing-locked-file-without-race-condition
fd = cast(int, self._lock_file_fd) fd = cast(int, self._context.lock_file_fd)
self._lock_file_fd = None self._context.lock_file_fd = None
fcntl.flock(fd, fcntl.LOCK_UN) fcntl.flock(fd, fcntl.LOCK_UN)
os.close(fd) os.close(fd)

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@ -2,9 +2,18 @@ from __future__ import annotations
import os import os
import stat import stat
import sys
from errno import EACCES, EISDIR
def raise_on_exist_ro_file(filename: str) -> None: 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
:param filename: file to check
:raises OSError: as if the file was opened for writing
"""
try: try:
file_stat = os.stat(filename) # use stat to do exists + can write to check without race condition file_stat = os.stat(filename) # use stat to do exists + can write to check without race condition
except OSError: except OSError:
@ -12,9 +21,17 @@ def raise_on_exist_ro_file(filename: str) -> None:
if file_stat.st_mtime != 0: # if os.stat returns but modification is zero that's an invalid os.stat - ignore it if file_stat.st_mtime != 0: # if os.stat returns but modification is zero that's an invalid os.stat - ignore it
if not (file_stat.st_mode & stat.S_IWUSR): if not (file_stat.st_mode & stat.S_IWUSR):
raise PermissionError(f"Permission denied: {filename!r}") raise PermissionError(EACCES, "Permission denied", filename)
if stat.S_ISDIR(file_stat.st_mode):
if sys.platform == "win32": # pragma: win32 cover
# On Windows, this is PermissionError
raise PermissionError(EACCES, "Permission denied", filename)
else: # pragma: win32 no cover
# On linux / macOS, this is IsADirectoryError
raise IsADirectoryError(EISDIR, "Is a directory", filename)
__all__ = [ __all__ = [
"raise_on_exist_ro_file", "raise_on_not_writable_file",
] ]

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@ -2,46 +2,48 @@ from __future__ import annotations
import os import os
import sys import sys
from errno import ENOENT from errno import EACCES
from typing import cast from typing import cast
from ._api import BaseFileLock from ._api import BaseFileLock
from ._util import raise_on_exist_ro_file from ._util import raise_on_not_writable_file
if sys.platform == "win32": # pragma: win32 cover if sys.platform == "win32": # pragma: win32 cover
import msvcrt import msvcrt
class WindowsFileLock(BaseFileLock): class WindowsFileLock(BaseFileLock):
"""Uses the :func:`msvcrt.locking` function to hard lock the lock file on windows systems.""" """Uses the :func:`msvcrt.locking` function to hard lock the lock file on Windows systems."""
def _acquire(self) -> None: def _acquire(self) -> None:
raise_on_exist_ro_file(self._lock_file) raise_on_not_writable_file(self.lock_file)
flags = ( flags = (
os.O_RDWR # open for read and write os.O_RDWR # open for read and write
| os.O_CREAT # create file if not exists | os.O_CREAT # create file if not exists
| os.O_TRUNC # truncate file if not empty | os.O_TRUNC # truncate file if not empty
) )
try: try:
fd = os.open(self._lock_file, flags, self._mode) fd = os.open(self.lock_file, flags, self._context.mode)
except OSError as exception: except OSError as exception:
if exception.errno == ENOENT: # No such file or directory if exception.errno != EACCES: # has no access to this lock
raise raise
else: else:
try: try:
msvcrt.locking(fd, msvcrt.LK_NBLCK, 1) msvcrt.locking(fd, msvcrt.LK_NBLCK, 1)
except OSError: except OSError as exception:
os.close(fd) os.close(fd) # close file first
if exception.errno != EACCES: # file is already locked
raise
else: else:
self._lock_file_fd = fd self._context.lock_file_fd = fd
def _release(self) -> None: def _release(self) -> None:
fd = cast(int, self._lock_file_fd) fd = cast(int, self._context.lock_file_fd)
self._lock_file_fd = None self._context.lock_file_fd = None
msvcrt.locking(fd, msvcrt.LK_UNLCK, 1) msvcrt.locking(fd, msvcrt.LK_UNLCK, 1)
os.close(fd) os.close(fd)
try: try:
os.remove(self._lock_file) os.remove(self.lock_file)
# Probably another instance of the application hat acquired the file lock. # Probably another instance of the application hat acquired the file lock.
except OSError: except OSError:
pass pass
@ -49,7 +51,7 @@ if sys.platform == "win32": # pragma: win32 cover
else: # pragma: win32 no cover else: # pragma: win32 no cover
class WindowsFileLock(BaseFileLock): class WindowsFileLock(BaseFileLock):
"""Uses the :func:`msvcrt.locking` function to hard lock the lock file on windows systems.""" """Uses the :func:`msvcrt.locking` function to hard lock the lock file on Windows systems."""
def _acquire(self) -> None: def _acquire(self) -> None:
raise NotImplementedError raise NotImplementedError

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@ -1,4 +1,4 @@
# file generated by setuptools_scm # file generated by setuptools_scm
# don't change, don't track in version control # don't change, don't track in version control
__version__ = version = '3.11.0' __version__ = version = '3.12.0'
__version_tuple__ = version_tuple = (3, 11, 0) __version_tuple__ = version_tuple = (3, 12, 0)