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# The ASF licenses this file to You under the Apache License, Version 2.0

# (the "License"); you may not use this file except in compliance with

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# http://www.apache.org/licenses/LICENSE-2.0

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import abc

from collections import deque

from enum import Enum

EPSILON = 1e-9

class BaseTracker(abc.ABC):

"""Abstract base class for all univariate trackers."""

@abc.abstractmethod

def push(self, x):

"""Push a new value to the tracker.

Args:

x: The value to be pushed.

"""

raise NotImplementedError()

@abc.abstractmethod

def get(self):

"""Get the current tracking value.

Returns:

The current tracked value, the type of which depends on the specific

tracker implementation.

"""

raise NotImplementedError()

class WindowMode(Enum):

"""Enum representing the window mode for windowed trackers."""

#: operating on all data points from the beginning.

LANDMARK = 1

#: operating on a fixed-size sliding window of recent data points.

SLIDING = 2

class WindowedTracker(BaseTracker):

"""Abstract base class for trackers that operate on a data window.

This class provides a foundation for trackers that maintain a window of data,

either as a landmark window or a sliding window. It provides basic push and

pop operations.

Args:

window_mode: A `WindowMode` enum specifying whether the window is `LANDMARK`

or `SLIDING`.

**kwargs: Keyword arguments.

For `SLIDING` window mode, `window_size` can be specified to set the

maximum size of the sliding window. Defaults to 100.

"""

def __init__(self, window_mode, **kwargs):

if window_mode == WindowMode.SLIDING:

self._window_size = kwargs.get("window_size", 100)

self._queue = deque(maxlen=self._window_size)

self._n = 0

self._window_mode = window_mode

def push(self, x):

"""Adds a new value to the data window.

Args:

x: The value to be added to the window.

"""

self._queue.append(x)

def pop(self):

"""Removes and returns the oldest value from the data window (FIFO).

Returns:

The oldest value from the window.

"""

return self._queue.popleft()