Class: SlideWindowCounter

Package: @litert/concurrentImport path: @litert/concurrentSource: packages/partials/concurrent/src/Classes/SlideWindowCounter.ts

A counter backed by a sliding time window. The window is divided into windowQty sub-windows of equal duration. Counts in expired sub-windows are automatically discarded when any method is called. The total represents only counts recorded within the current sliding window.

Also implements ICounter, so it can be used directly with CountingRateLimiter and CircuitBreaker.

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Constructor

new SlideWindowCounter(options?: ISlideWindowCounterOptions)

See ISlideWindowCounterOptions.

Throws:

• Error — if windowQty or windowSizeMs is not a positive safe integer.

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Properties

Property	Type	Description
windowSize	number (readonly)	Total window duration in milliseconds
windowQty	number (readonly)	Number of sub-windows

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Methods

getTotal()

getTotal(): number

Returns the total count across all active (non-expired) sub-windows.

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increase(step?)

increase(step?: number): void

Increments the count in the current sub-window.

Parameter	Type	Default	Description
step	number?	1	Amount to add

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reset()

reset(): void

Clears all sub-window data, resetting the total to zero.

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getWindows()

getWindows(): ReadonlyArray<{ time: number; count: number }>

Returns a snapshot of the current sub-windows, each with a time (start timestamp) and count.

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Example

import { SlideWindowCounter } from '@litert/concurrent';

const counter = new SlideWindowCounter({
    windowSizeMs: 10_000, // 10-second window
    windowQty: 5,          // divided into five 2-second sub-windows
});

counter.increase();
counter.increase(3);

console.log(counter.getTotal()); // 4