UNPKG

@libp2p/prometheus-metrics

Version:

Collect libp2p metrics for scraping by Prometheus or Graphana

45 lines (37 loc) 1.32 kB
import { Histogram as PromHistogram } from 'prom-client' import { normalizeString } from './utils.js' import type { PrometheusCalculatedHistogramOptions } from './index.js' import type { StopTimer, Histogram } from '@libp2p/interface' import type { CollectFunction } from 'prom-client' export class PrometheusHistogram implements Histogram { private readonly histogram: PromHistogram constructor (name: string, opts: PrometheusCalculatedHistogramOptions) { name = normalizeString(name) const help = normalizeString(opts.help ?? name) const labels = opts.label != null ? [normalizeString(opts.label)] : [] let collect: CollectFunction<PromHistogram<any>> | undefined // calculated metric if (opts?.calculate != null) { collect = async function () { this.observe(await opts.calculate()) } } this.histogram = new PromHistogram({ name, help, buckets: opts.buckets ?? [0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10], labelNames: labels, registers: opts.registry !== undefined ? [opts.registry] : undefined, collect }) } observe (value: number): void { this.histogram.observe(value) } reset (): void { this.histogram.reset() } timer (): StopTimer { return this.histogram.startTimer() } }