RateTracker

RateTracker(window_seconds: float = 60.0) -> None

Computes the per-minute rate of a monotonically increasing counter over a trailing time window.

Fed the cumulative counter value periodically (for example from the system-metrics loop), it returns (delta value / delta seconds) * 60 measured over the window. It tolerates the counter not advancing and irregular update intervals. Returns 0.0 until at least two samples span a positive interval.

Initialize the rate tracker.

Parameters:

• window_seconds (float) – The trailing window over which the rate is averaged.

Source

Methods

update

update(value: float, *, now: float | None = None) -> float

Record the latest cumulative counter value and return the current per-minute rate.

Parameters:

• value (float) – The cumulative counter value.
• now (float | None) – Optional timestamp override (for testing); defaults to time.time().

Returns:

• float – The per-minute rate over the window, or 0.0 when not yet computable.

Source