cronometro/dist/tracker.js

Simple benchmarking suite powered by HDR histograms.

import { build } from 'hdr-histogram-js';
import { percentiles } from "./models.js";
export class Tracker {
    iterations;
    histogram;
    error;
    constructor() {
        this.iterations = 0;
        this.error = undefined;
        this.histogram = build({
            lowestDiscernibleValue: 1,
            highestTrackableValue: 1e9,
            numberOfSignificantValueDigits: 5
        });
    }
    get results() {
        if (typeof this.error !== 'undefined') {
            return {
                success: false,
                error: this.error,
                size: 0,
                min: 0,
                max: 0,
                mean: 0,
                stddev: 0,
                percentiles: {},
                standardError: 0
            };
        }
        const size = this.iterations;
        const { minNonZeroValue: min, maxValue: max, mean, stdDeviation } = this.histogram;
        return {
            success: true,
            size,
            min,
            max,
            mean,
            stddev: stdDeviation,
            percentiles: Object.fromEntries(percentiles.map(percentile => [percentile, this.histogram.getValueAtPercentile(percentile)])),
            standardError: stdDeviation / Math.sqrt(size)
        };
    }
    get standardError() {
        return this.histogram.stdDeviation / Math.sqrt(this.iterations);
    }
    track(start) {
        // Grab duration even in case of error to make sure we don't add any overhead to the benchmark
        const duration = Number(process.hrtime.bigint() - start);
        this.histogram.recordValue(duration);
        this.iterations++;
    }
}