performance-service.ts

import { TrackActionNames } from "../constants";
const EOL = require("os").EOL;
import { getFixedLengthDateString } from "../common/helpers";
import * as semver from "semver";
import * as _ from "lodash";
import { IPerformanceService, IOptions } from "../declarations";
import { IFileSystem, IAnalyticsService } from "../common/declarations";
import { injector } from "../common/yok";

export class PerformanceService implements IPerformanceService {
	public static LOG_MESSAGE_TEMPLATE = `Execution of method "%s" took %s ms.`;
	public static FAIL_LOG_MESSAGE_TEMPLATE = `Failed to log pefromance data in file for method %s.`;
	private static MIN_NODE_PERFORMANCE_MODULE_VERSION = "8.5.0";
	private performance: { now(): number } = null;

	constructor(
		private $options: IOptions,
		private $fs: IFileSystem,
		private $logger: ILogger,
		private $analyticsService: IAnalyticsService
	) {
		if (this.isPerformanceModuleSupported()) {
			this.performance = require("perf_hooks").performance;
		}
	}

	public processExecutionData(
		methodInfo: string,
		startTime: number,
		endTime: number,
		args: any[]
	): void {
		const executionTime = Math.floor(endTime - startTime);

		this.trackAnalyticsData(methodInfo, executionTime);

		if (typeof this.$options.performance === "string") {
			this.logDataToFile(
				this.$options.performance,
				methodInfo,
				executionTime,
				args
			);
		} else if (this.$options.performance) {
			this.$logger.info(
				PerformanceService.LOG_MESSAGE_TEMPLATE,
				methodInfo,
				executionTime
			);
		}
	}

	public now(): number {
		if (this.isPerformanceModuleSupported()) {
			return this.performance.now();
		} else {
			return new Date().getTime();
		}
	}

	private isPerformanceModuleSupported(): boolean {
		return semver.gte(
			process.version,
			PerformanceService.MIN_NODE_PERFORMANCE_MODULE_VERSION
		);
	}

	private trackAnalyticsData(methodInfo: string, executionTime: number): void {
		this.$analyticsService
			.trackEventActionInGoogleAnalytics({
				action: TrackActionNames.Performance,
				additionalData: methodInfo,
				value: executionTime,
			})
			.catch((err) => {
				throw err;
			});
	}

	private logDataToFile(
		filePath: string,
		methodInfo: string,
		executionTime: number,
		args: any[]
	) {
		let methodArgs;

		try {
			methodArgs = JSON.stringify(args, this.getJsonSanitizer());
		} catch (e) {
			methodArgs = "cyclic args";
		}

		const info = {
			methodInfo,
			executionTime,
			timestamp: getFixedLengthDateString(),
			methodArgs: JSON.parse(methodArgs),
		};

		try {
			this.$fs.appendFile(filePath, `${JSON.stringify(info)}${EOL}`);
		} catch (e) {
			this.$logger.trace(
				PerformanceService.FAIL_LOG_MESSAGE_TEMPLATE,
				methodInfo
			);
			this.$logger.info(
				PerformanceService.LOG_MESSAGE_TEMPLATE,
				methodInfo,
				executionTime
			);
		}
	}

	//removes any injected members of the arguments and excludes the options object even if it was renamed
	private getJsonSanitizer() {
		const seen = new WeakSet();
		seen.add(this.$options);
		return (key: any, value: any) => {
			if (typeof value === "object" && value !== null) {
				if (seen.has(value) || _.startsWith(key, "$")) {
					return;
				}
				seen.add(value);
			}
			return value;
		};
	}
}

injector.register("performanceService", PerformanceService);