Class: LeakyBucketRateLimiterManager

Package: @litert/concurrentImport path: @litert/concurrentSource: packages/partials/concurrent/src/Classes/LeakyBucketRateLimiterManager.tsImplements: IAsyncRateLimiterManager

Manages a collection of per-key leaky-bucket rate limiters. Each key gets its own scheduling queue so concurrent calls to different keys do not interfere.

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Constructor

new LeakyBucketRateLimiterManager(opts: ILeakyBucketRateLimiterManagerOptions)

See ILeakyBucketRateLimiterManagerOptions.

Throws:

• TypeError — if capacity or leakIntervalMs is not a positive safe integer.
• TypeError — if cleanDelayMs is negative.

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Methods

challenge(key)

challenge(key: string): Promise<void>

Waits until the next available slot for key, then resolves. Throws if the queue for that key is already at capacity.

Throws: E_RATE_LIMITED (or custom error).

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isBlocking(key)

isBlocking(key: string): boolean

Returns true if a challenge for key would need to wait.

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call(key, fn)

call<T extends IFunction>(key: string, fn: T): Promise<Awaited<ReturnType<T>>>

Awaits challenge(key), then calls fn.

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reset(key)

reset(key: string): void

Resets the schedule for key so the next call proceeds immediately.

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size()

size(): number

Returns the number of active key contexts.

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clean()

clean(): void

Removes key contexts that are currently idle and have been so for at least cleanDelayMs milliseconds.

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Scoped Types

Interface ILeakyBucketRateLimiterManagerOptions

Source: LeakyBucketRateLimiterManager.ts

import type { ILeakyBucketRateLimiterManagerOptions } from '@litert/concurrent';

interface ILeakyBucketRateLimiterManagerOptions {
    capacity: number;
    leakIntervalMs: number;
    cleanDelayMs?: number;
    errorCtorOnLimited?: IConstructor<Error>;
}

Property	Type	Default	Description
capacity	number	—	Max pending tasks per key
leakIntervalMs	number	—	Milliseconds per task leakage
cleanDelayMs	number?	0	Keep idle context for this long before cleaning; 0 = disabled
errorCtorOnLimited	IConstructor<Error>?	E_RATE_LIMITED	Custom error class

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Example

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

const manager = new LeakyBucketRateLimiterManager({
    capacity: 5,
    leakIntervalMs: 200,
    cleanDelayMs: 10_000,
});

async function handleApiCall(userId: string) {
    await manager.challenge(userId);
    return callApi(userId);
}