profilingHooks.js — react Source File

Source Code

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */

import type {
  Lane,
  Lanes,
  DevToolsProfilingHooks,
  WorkTagMap,
  CurrentDispatcherRef,
} from 'react-devtools-shared/src/backend/types';
import type {Fiber} from 'react-reconciler/src/ReactInternalTypes';
import type {Wakeable} from 'shared/ReactTypes';
import type {
  BatchUID,
  InternalModuleSourceToRanges,
  LaneToLabelMap,
  ReactComponentMeasure,
  ReactLane,
  ReactMeasure,
  ReactMeasureType,
  ReactScheduleStateUpdateEvent,
  SchedulingEvent,
  SuspenseEvent,
  TimelineData,
} from 'react-devtools-timeline/src/types';

import isArray from 'shared/isArray';
import {
  REACT_TOTAL_NUM_LANES,
  SCHEDULING_PROFILER_VERSION,
} from 'react-devtools-timeline/src/constants';
import {describeFiber} from './fiber/DevToolsFiberComponentStack';

// Add padding to the start/stop time of the profile.
// This makes the UI nicer to use.
const TIME_OFFSET = 10;

let performanceTarget: Performance | null = null;

// If performance exists and supports the subset of the User Timing API that we require.
let supportsUserTiming =
  typeof performance !== 'undefined' &&
  // $FlowFixMe[method-unbinding]
  typeof performance.mark === 'function' &&
  // $FlowFixMe[method-unbinding]
  typeof performance.clearMarks === 'function';

let supportsUserTimingV3 = false;
if (supportsUserTiming) {
  const CHECK_V3_MARK = '__v3';
  const markOptions: {
    detail?: mixed,
    startTime?: number,
  } = {};
// ... (930 more lines)