@bugsnag/core-performance/dist/sampler.js

Core performance client

// sampling rates are stored as a number between 0 and 2^32 - 1 (i.e. they are
// u32s) so we need to scale the probability value to match this range as they
// are stored as values between 0 and 1
function scaleProbabilityToMatchSamplingRate(probability) {
    return Math.floor(probability * 0xffffffff);
}
class Sampler {
    constructor(initialProbability) {
        // we could just do 'this.probability = initialProbability' but TypeScript
        // doesn't like that as it doesn't directly initialise these properties in
        // the constructor
        this._probability = initialProbability;
        this.scaledProbability = scaleProbabilityToMatchSamplingRate(initialProbability);
    }
    /**
     * The global probability value: a number between 0 & 1
     */
    get probability() {
        return this._probability;
    }
    set probability(probability) {
        this._probability = probability;
        this.scaledProbability = scaleProbabilityToMatchSamplingRate(probability);
    }
    /**
     * The probability value for spans: a number between 0 & 2^32 - 1
     *
     * This is necessary because span sampling rates are generated as unsigned 32
     * bit integers. We scale the global probability value to match that range, so
     * that we can use a simple calculation in 'sample'
     *
     * @see scaleProbabilityToMatchSamplingRate
     */
    get spanProbability() {
        return {
            raw: this._probability,
            scaled: this.scaledProbability
        };
    }
    sample(span) {
        return span.samplingRate <= span.samplingProbability.scaled;
    }
    shouldSample(samplingRate) {
        return samplingRate <= this.spanProbability.scaled;
    }
}

export { Sampler as default, scaleProbabilityToMatchSamplingRate };