59 lines
1.7 KiB
Python
59 lines
1.7 KiB
Python
from threading import RLock
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from typing import Optional
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from reactivex import abc
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class SerialDisposable(abc.DisposableBase):
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"""Represents a disposable resource whose underlying disposable
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resource can be replaced by another disposable resource, causing
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automatic disposal of the previous underlying disposable resource.
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"""
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def __init__(self) -> None:
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self.current: Optional[abc.DisposableBase] = None
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self.is_disposed = False
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self.lock = RLock()
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super().__init__()
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def get_disposable(self) -> Optional[abc.DisposableBase]:
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return self.current
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def set_disposable(self, value: abc.DisposableBase) -> None:
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"""If the SerialDisposable has already been disposed, assignment
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to this property causes immediate disposal of the given
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disposable object. Assigning this property disposes the previous
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disposable object."""
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old: Optional[abc.DisposableBase] = None
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with self.lock:
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should_dispose = self.is_disposed
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if not should_dispose:
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old = self.current
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self.current = value
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if old is not None:
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old.dispose()
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if should_dispose and value is not None:
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value.dispose()
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disposable = property(get_disposable, set_disposable)
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def dispose(self) -> None:
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"""Disposes the underlying disposable as well as all future
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replacements."""
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old: Optional[abc.DisposableBase] = None
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with self.lock:
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if not self.is_disposed:
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self.is_disposed = True
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old = self.current
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self.current = None
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if old is not None:
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old.dispose()
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