deno.land / x / jotai@v1.8.4 / src / core / suspensePromise.ts
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374const SUSPENSE_PROMISE = Symbol()
interface SuspensePromiseExtra { b: Promise<unknown> // base promise o: Promise<void> // original promise c: (() => void) | null // cancel promise (null if already cancelled)}
// Not exported for public APIexport type SuspensePromise = Promise<void> & { [SUSPENSE_PROMISE]: SuspensePromiseExtra}
export const isSuspensePromise = ( promise: Promise<void>): promise is SuspensePromise => !!(promise as SuspensePromise)[SUSPENSE_PROMISE]
export const isSuspensePromiseAlreadyCancelled = ( suspensePromise: SuspensePromise) => !suspensePromise[SUSPENSE_PROMISE].c
export const cancelSuspensePromise = (suspensePromise: SuspensePromise) => { const { b: basePromise, c: cancelPromise } = suspensePromise[SUSPENSE_PROMISE] if (cancelPromise) { cancelPromise() promiseAbortMap.get(basePromise)?.() }}
// Note: this is a special equality functionexport const isEqualSuspensePromise = ( oldSuspensePromise: SuspensePromise, newSuspensePromise: SuspensePromise): boolean => { const oldOriginalPromise = oldSuspensePromise[SUSPENSE_PROMISE].o const newOriginalPromise = newSuspensePromise[SUSPENSE_PROMISE].o return ( oldOriginalPromise === newOriginalPromise || oldSuspensePromise === newOriginalPromise || (isSuspensePromise(oldOriginalPromise) && isEqualSuspensePromise(oldOriginalPromise, newSuspensePromise)) )}
export const createSuspensePromise = ( basePromise: Promise<unknown>, promise: Promise<void>): SuspensePromise => { const suspensePromiseExtra: SuspensePromiseExtra = { b: basePromise, o: promise, c: null, } const suspensePromise = new Promise<void>((resolve) => { suspensePromiseExtra.c = () => { suspensePromiseExtra.c = null resolve() } promise.finally(suspensePromiseExtra.c) }) as SuspensePromise suspensePromise[SUSPENSE_PROMISE] = suspensePromiseExtra return suspensePromise}
const promiseAbortMap = new WeakMap<Promise<unknown>, () => void>()
export const registerPromiseAbort = ( basePromise: Promise<unknown>, abort: () => void) => { promiseAbortMap.set(basePromise, abort)}
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