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fc3777b1fe
Add a new component type, Profiler, that can be used to collect new render time metrics. Since this is a new, experimental API, it will be exported as React.unstable_Profiler initially. Most of the functionality for this component has been added behind a feature flag, enableProfileModeMetrics. When the feature flag is disabled, the component will just render its children with no additional behavior. When the flag is enabled, React will also collect timing information and pass it to the onRender function (as described below).
47 lines
1.7 KiB
JavaScript
47 lines
1.7 KiB
JavaScript
/**
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* Copyright (c) 2013-present, Facebook, Inc.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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* @flow
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*/
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import invariant from 'fbjs/lib/invariant';
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// Exports ReactDOM.createRoot
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export const enableUserTimingAPI = __DEV__;
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// Mutating mode (React DOM, React ART, React Native):
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export const enableMutatingReconciler = true;
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// Experimental noop mode (currently unused):
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export const enableNoopReconciler = false;
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// Experimental persistent mode (Fabric):
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export const enablePersistentReconciler = false;
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// Experimental error-boundary API that can recover from errors within a single
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// render phase
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export const enableGetDerivedStateFromCatch = false;
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// Helps identify side effects in begin-phase lifecycle hooks and setState reducers:
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export const debugRenderPhaseSideEffects = false;
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// In some cases, StrictMode should also double-render lifecycles.
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// This can be confusing for tests though,
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// And it can be bad for performance in production.
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// This feature flag can be used to control the behavior:
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export const debugRenderPhaseSideEffectsForStrictMode = __DEV__;
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// To preserve the "Pause on caught exceptions" behavior of the debugger, we
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// replay the begin phase of a failed component inside invokeGuardedCallback.
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export const replayFailedUnitOfWorkWithInvokeGuardedCallback = __DEV__;
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// Warn about deprecated, async-unsafe lifecycles; relates to RFC #6:
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export const warnAboutDeprecatedLifecycles = false;
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// Gather advanced timing metrics for Profiler subtrees.
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export const enableProfilerTimer = false;
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// Only used in www builds.
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export function addUserTimingListener() {
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invariant(false, 'Not implemented.');
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}
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