@woosh/meep-engine/src/engine/development/performance/MetricCollection.js

Pure JavaScript game engine. Fully featured and production ready.

import { assert } from "../../../core/assert.js";
import { RingBufferMetric } from "./RingBufferMetric.js";

/**
 * A class for managing a collection of metrics where each metric can store data and be accessed by name.
 * Provides functionality to add, retrieve, list, and clear metrics.
 *
 * @example
 *   const metrics = new MetricCollection();
 *   metrics.create({name: "execution time"});
 *
 *   // ... record metrics
 *   const t0 = performance.now();
 *   do_expensive_computation();
 *   const t1 = performance.now();
 *
 *   metrics.get("execution time").record(t1 - t0);
 *
 *   // ... read stats
 *   const stats = metrics.get("execution time").stats;
 *
 *   console.log(`Average execution time: ${stats.mean}`);
 */
export class MetricCollection {

    /**
     * @private
     * @type {Map<string, AbstractMetric>}
     */
    data = new Map();

    /**
     * Clear all data records.
     * Note: does not remove any metrics, just the data within them
     */
    clear() {
        this.data.forEach((value, key) => {
            value.clear();
        });
    }

    /**
     * Get names of available metrics
     * @returns {string[]}
     */
    list() {
        return Array.from(this.data.keys());
    }

    /**
     *
     * @param {string} name
     * @param {number} [buffer_size] The larger this number is - the more detail metric can hold. If you plan to compute statistics, this is your sample size.
     * @returns {AbstractMetric}
     */
    create({ name, buffer_size = 128 }) {
        const metric = new RingBufferMetric(buffer_size);

        this.add(name, metric);

        return metric;
    }

    /**
     *
     * @param {string} name
     * @param {AbstractMetric} metric
     */
    add(name, metric) {
        assert.isString(name, 'name');
        assert.defined(metric, 'metric');
        assert.isObject(metric, "metric");
        assert.equal(metric.isMetric, true, "metric");

        this.data.set(name, metric);
    }

    /**
     *
     * @param {string} name
     * @returns {AbstractMetric|undefined}
     */
    get(name) {
        assert.isString(name, 'name');

        return this.data.get(name);
    }
}