94 lines
2.5 KiB
Python
94 lines
2.5 KiB
Python
from __future__ import annotations
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from typing import Union, Callable, Optional
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from cpl_reactive_extensions.abc.unsubscribable import Unsubscribable
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class Subscription(Unsubscribable):
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@staticmethod
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def empty():
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empty = Subscription()
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empty.closed = True
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return empty
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def __init__(self, initial_teardown: Optional[Callable] = None):
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Unsubscribable.__init__(self)
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self._initial_teardown = initial_teardown
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self._closed = False
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self._parentage: list[Subscription] = []
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self._finalizers: list[Subscription] = []
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@property
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def closed(self) -> bool:
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return self._closed
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@closed.setter
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def closed(self, value: bool):
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self._closed = value
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def _add_parent(self, parent: Subscription):
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self._parentage.append(parent)
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def _remove_parent(self, parent: Subscription):
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if self == parent:
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self._parentage.clear()
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return
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self._parentage.remove(parent)
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def _has_parent(self, parent: Subscription) -> bool:
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return parent in self._parentage
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def _exec_finalizer(self, finalizer: Union[Callable, Unsubscribable]):
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if isinstance(finalizer, Callable):
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finalizer()
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else:
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finalizer.unsubscribe()
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def unsubscribe(self):
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if not self._closed:
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self._closed = True
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for parent in self._parentage:
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parent.remove(self)
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if self._initial_teardown is not None:
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try:
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self._initial_teardown()
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except Exception as e:
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print(e)
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finalizers = self._finalizers
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self._finalizers = None
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for finalizer in finalizers:
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try:
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self._exec_finalizer(finalizer)
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except Exception as e:
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print(e)
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def add(self, tear_down: Union[Subscription, Unsubscribable]):
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if tear_down is None or tear_down == self:
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return
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if self.closed:
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self._exec_finalizer(tear_down)
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return
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if isinstance(tear_down, Subscription):
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if tear_down.closed or tear_down._has_parent(self):
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return
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tear_down._add_parent(self)
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self._finalizers.append(tear_down)
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def remove(self, tear_down: Union[Subscription, Unsubscribable]):
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self._finalizers.remove(tear_down)
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if isinstance(tear_down, Subscription):
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tear_down._remove_parent(self)
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