import { SemaphorePool, SemaphorePoolConfig } from './semaphore.js';
declare const outcomes: readonly ["fulfilled", "timedout", "canceled", "rejected", "unspecified"];
export type SemaphorePoolLabels = {
    pool: string;
};
export type SemaphoreLabels = SemaphorePoolLabels & {
    operation: string;
};
export type SemaphoreSettledLabels = SemaphorePoolLabels & SemaphoreLabels & {
    outcome: typeof outcomes[number];
};
export declare const defaultHistoBucketsMS: number[];
export type MetricOptions = {
    histogramBucketsMS?: number[];
};
interface CounterMetric<T extends string> {
    inc(labels: Record<T, string | number>): void;
    init(labels: Record<T, string | number>): void;
}
interface GaugeMetric<T extends string> {
    set(labels: Record<T, string | number>, value: number): void;
}
interface HistogramMetric<T extends string> {
    observe(labels: Record<T, string | number>, value: number): void;
}
export type SemaphoreMetrics = {
    requested: CounterMetric<keyof SemaphoreLabels>;
    released: CounterMetric<keyof SemaphoreLabels>;
    settled: CounterMetric<keyof SemaphoreSettledLabels>;
    reserved: GaugeMetric<keyof SemaphoreLabels>;
    queued: GaugeMetric<keyof SemaphoreLabels>;
    concurrency: GaugeMetric<keyof SemaphorePoolLabels>;
    capacity: GaugeMetric<keyof SemaphorePoolLabels>;
    waittime: HistogramMetric<keyof SemaphoreSettledLabels>;
    heldtime: HistogramMetric<keyof SemaphoreLabels>;
};
export interface InstrumentedSemaphorePoolConfig extends SemaphorePoolConfig {
    defaultOperation?: string;
}
export default abstract class InstrumentedSemaphorePoolFactory {
    abstract get metrics(): SemaphoreMetrics;
    instrumentedPool(name: string, config: InstrumentedSemaphorePoolConfig): SemaphorePool;
}
export {};