@metrics/process/lib/collector-open-file-descriptors.js

Module for collecting different process and system metrics and providing them as a metric stream

"use strict";

const Metric = require("@metrics/metric");
const fs = require("fs");

const CollectorOpenFileDescriptors = class CollectorOpenFileDescriptors {
	constructor(prefix = "") {
		Object.defineProperty(this, "prefix", {
			value: prefix,
		});
	}

	get [Symbol.toStringTag]() {
		return "CollectorOpenFileDescriptors";
	}

	collect(timestamp) {
		if (process.platform !== "linux") {
			return null;
		}

		return new Promise((resolve) => {
			fs.readdir("/proc/self/fd", (error, result) => {
				if (error) {
					resolve(null);
					return;
				}

				resolve([
					new Metric({
						name: `${this.prefix}process_open_fds`,
						description: "Number of open file descriptors",
						type: 1,
						value: result.length - 1,
						timestamp,
					}),
				]);
			});
		});
	}
};

module.exports = CollectorOpenFileDescriptors;