create-expo-cljs-app/template/node_modules/react-native-web/dist/vendor/react-native/JSEventLoopWatchdog/index.js.flow

Create a react native application with Expo and Shadow-CLJS!

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @format
 * @flow
 */
'use strict';

import infoLog from '../infoLog';
import performanceNow from 'fbjs/lib/performanceNow';
type Handler = {
  onIterate?: () => void,
  onStall: (params: {
    lastInterval: number,
    busyTime: number,
  }) => ?string,
};
/**
 * A utility for tracking stalls in the JS event loop that prevent timers and
 * other events from being processed in a timely manner.
 *
 * The "stall" time is defined as the amount of time in access of the acceptable
 * threshold, which is typically around 100-200ms. So if the treshold is set to
 * 100 and a timer fires 150 ms later than it was scheduled because the event
 * loop was tied up, that would be considered a 50ms stall.
 *
 * By default, logs stall events to the console when installed. Can also be
 * queried with `getStats`.
 */

const JSEventLoopWatchdog = {
  getStats: function (): Object {
    return {
      stallCount,
      totalStallTime,
      longestStall,
      acceptableBusyTime
    };
  },
  reset: function () {
    infoLog('JSEventLoopWatchdog: reset');
    totalStallTime = 0;
    stallCount = 0;
    longestStall = 0;
    lastInterval = performanceNow();
  },
  addHandler: function (handler: Handler) {
    handlers.push(handler);
  },
  install: function ({
    thresholdMS
  }: {
    thresholdMS: number
  }) {
    acceptableBusyTime = thresholdMS;

    if (installed) {
      return;
    }

    installed = true;
    lastInterval = performanceNow();
    declare function iteration(): any;
    iteration();
  }
};
let acceptableBusyTime = 0;
let installed = false;
let totalStallTime = 0;
let stallCount = 0;
let longestStall = 0;
let lastInterval = 0;
const handlers: Array<Handler> = [];
export default JSEventLoopWatchdog;