firestar5683
56 lines
1.7 KiB
Python
56 lines
1.7 KiB
Python
from typing import Callable, List, Optional, TypeVar
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from reactivex import Observable, abc
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_T = TypeVar("_T")
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def take_last_buffer_(count: int) -> Callable[[Observable[_T]], Observable[List[_T]]]:
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def take_last_buffer(source: Observable[_T]) -> Observable[List[_T]]:
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"""Returns an array with the specified number of contiguous
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elements from the end of an observable sequence.
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Example:
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>>> res = take_last(source)
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This operator accumulates a buffer with a length enough to
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store elements count elements. Upon completion of the source
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sequence, this buffer is drained on the result sequence. This
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causes the elements to be delayed.
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Args:
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source: Source observable to take elements from.
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Returns:
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An observable sequence containing a single list with the
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specified number of elements from the end of the source
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sequence.
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"""
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def subscribe(
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observer: abc.ObserverBase[List[_T]],
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scheduler: Optional[abc.SchedulerBase] = None,
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) -> abc.DisposableBase:
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q: List[_T] = []
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def on_next(x: _T) -> None:
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with source.lock:
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q.append(x)
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if len(q) > count:
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q.pop(0)
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def on_completed() -> None:
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observer.on_next(q)
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observer.on_completed()
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return source.subscribe(
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on_next, observer.on_error, on_completed, scheduler=scheduler
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)
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return Observable(subscribe)
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return take_last_buffer
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__all__ = ["take_last_buffer_"]
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