42 lines
1.0 KiB
Plaintext
42 lines
1.0 KiB
Plaintext
let nextHandle = 1;
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const RESOLVED = (() => Promise.resolve())();
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const activeHandles: { [key: number]: any } = {};
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/**
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* Finds the handle in the list of active handles, and removes it.
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* Returns `true` if found, `false` otherwise. Used both to clear
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* Immediate scheduled tasks, and to identify if a task should be scheduled.
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*/
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function findAndClearHandle(handle: number): boolean {
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if (handle in activeHandles) {
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delete activeHandles[handle];
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return true;
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}
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return false;
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}
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/**
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* Helper functions to schedule and unschedule microtasks.
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*/
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export const Immediate = {
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setImmediate(cb: () => void): number {
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const handle = nextHandle++;
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activeHandles[handle] = true;
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RESOLVED.then(() => findAndClearHandle(handle) && cb());
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return handle;
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},
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clearImmediate(handle: number): void {
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findAndClearHandle(handle);
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},
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};
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/**
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* Used for internal testing purposes only. Do not export from library.
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*/
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export const TestTools = {
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pending() {
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return Object.keys(activeHandles).length;
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}
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};
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