115 строки
3.8 KiB
JavaScript
115 строки
3.8 KiB
JavaScript
/**
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* Copyright (c) Facebook, Inc. and its affiliates.
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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 strict
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* @format
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*/
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// Declarations for functionality exposed by the Hermes VM.
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//
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// For backwards-compatibility, code that uses such functionality must also
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// check explicitly at run-time whether the object(s) and method(s) exist, and
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// fail safely if not.
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/**
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* HermesInternalType is an object containing functions used to interact with
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* the VM in a way that is not standardized by the JS spec.
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* There are limited guarantees about these functions, and they should not be
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* widely used. Consult with the Hermes team before using any of these.
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* There may be other visible properties on this object; however, those are
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* only exposed for testing purposes: do not use them.
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*/
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declare type $HermesInternalType = {
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// All members are optional because they may not exist when OTA'd to older
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// VMs.
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+getNumGCs?: () => number,
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+getGCTime?: () => number,
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+getNativeCallTime?: () => number,
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+getNativeCallCount?: () => number,
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+getGCCPUTime?: () => number,
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/**
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* Hermes can embed an "epilogue" to the bytecode file with arbitrary bytes.
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* At most one epilogue will exist per bytecode module (which can be
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* different than a JS module).
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* Calling this function will return all such epilogues and convert the
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* bytes to numbers in the range of 0-255.
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*/
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+getEpilogues?: () => Array<Array<number>>,
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/**
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* Query the VM for various statistics about performance.
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* There are no guarantees about what keys exist in it, but they can be
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* printed for informational purposes.
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* @return An object that maps strings to various types of performance
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* statistics.
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*/
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+getInstrumentedStats?: () => {[string]: number | string, ...},
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/**
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* Query the VM for any sort of runtime properties that it wants to report.
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* There are no guarantees about what keys exist in it, but they can be
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* printed for informational purposes.
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* @return An object that maps strings to various types of runtime properties.
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*/
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+getRuntimeProperties?: () => {
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'OSS Release Version': string,
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Build: string,
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[string]: mixed,
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},
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/**
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* Tell Hermes that at this point the surface has transitioned from TTI to
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* post-TTI. The VM can change some of its internal behavior to optimize for
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* post-TTI scenarios.
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* This can be called several times but will have no effect after the first
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* call.
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*/
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+ttiReached?: () => void,
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/**
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* Tell Hermes that at this point the surface has transitioned from TTRC to
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* post-TTRC. The VM can change some of its internal behavior to optimize for
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* post-TTRC scenarios.
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* This can be called several times but will have no effect after the first
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* call.
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*/
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+ttrcReached?: () => void,
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/**
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* Query the VM to see whether or not it enabled Promise.
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*/
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+hasPromise?: () => boolean,
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/**
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* Enable promise rejection tracking with the given options.
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* The API mirrored the `promise` npm package, therefore it's typed same as
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* the `enable` function of module `promise/setimmediate/rejection-tracking`
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* declared in ./flow-typed/npm/promise_v8.x.x.js.
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*/
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+enablePromiseRejectionTracker?: (
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options: ?{
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whitelist?: ?Array<mixed>,
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allRejections?: ?boolean,
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onUnhandled?: ?(number, mixed) => void,
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onHandled?: ?(number, mixed) => void,
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},
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) => void,
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/**
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* Query the VM to see whether or not it use the engine Job queue.
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*/
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+useEngineQueue?: () => boolean,
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/**
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* Enqueue a JavaScript callback function as a Job into the engine Job queue.
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*/
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+enqueueJob?: <TArguments: Array<mixed>>(
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jobCallback: (...args: TArguments) => mixed,
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) => void,
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};
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