Cours/venv/lib/python3.12/site-packages/watchdog/utils/bricks.py

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2024-09-02 16:55:06 +00:00
"""Utility collections or "bricks".
:module: watchdog.utils.bricks
:author: yesudeep@google.com (Yesudeep Mangalapilly)
:author: lalinsky@gmail.com (Lukáš Lalinský)
:author: python@rcn.com (Raymond Hettinger)
:author: contact@tiger-222.fr (Mickaël Schoentgen)
Classes
=======
.. autoclass:: OrderedSetQueue
:members:
:show-inheritance:
:inherited-members:
.. autoclass:: OrderedSet
"""
from __future__ import annotations
import queue
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from typing import Any
class SkipRepeatsQueue(queue.Queue):
"""Thread-safe implementation of an special queue where a
put of the last-item put'd will be dropped.
The implementation leverages locking already implemented in the base class
redefining only the primitives.
Queued items must be immutable and hashable so that they can be used
as dictionary keys. You must implement **only read-only properties** and
the :meth:`Item.__hash__()`, :meth:`Item.__eq__()`, and
:meth:`Item.__ne__()` methods for items to be hashable.
An example implementation follows::
class Item:
def __init__(self, a, b):
self._a = a
self._b = b
@property
def a(self):
return self._a
@property
def b(self):
return self._b
def _key(self):
return (self._a, self._b)
def __eq__(self, item):
return self._key() == item._key()
def __ne__(self, item):
return self._key() != item._key()
def __hash__(self):
return hash(self._key())
based on the OrderedSetQueue below
"""
def _init(self, maxsize: int) -> None:
super()._init(maxsize)
self._last_item = None
def _put(self, item: Any) -> None:
if self._last_item is None or item != self._last_item:
super()._put(item)
self._last_item = item
else:
# `put` increments `unfinished_tasks` even if we did not put
# anything into the queue here
self.unfinished_tasks -= 1
def _get(self) -> Any:
item = super()._get()
if item is self._last_item:
self._last_item = None
return item