50 lines
1.4 KiB
Python
50 lines
1.4 KiB
Python
from threading import RLock
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from typing import Optional
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from reactivex.abc import DisposableBase
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class MultipleAssignmentDisposable(DisposableBase):
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"""Represents a disposable resource whose underlying disposable
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resource can be replaced by another disposable resource."""
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def __init__(self) -> None:
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self.current: Optional[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[DisposableBase]:
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return self.current
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def set_disposable(self, value: DisposableBase) -> None:
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"""If the MultipleAssignmentDisposable has already been
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disposed, assignment to this property causes immediate disposal
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of the given disposable object."""
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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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self.current = value
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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 = 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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