15 lines
503 B
TypeScript
15 lines
503 B
TypeScript
 
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/**
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* Share one in-flight promise per key: callers that ask again while a request
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* for the same key is still pending get that request instead of a new one.
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*/
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export function dedupeInFlight<T>(): (key: string, run: () => Promise<T>) => Promise<T> {
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const pending = new Map<string, Promise<T>>();
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return (key, run) => {
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const existing = pending.get(key);
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if (existing) return existing;
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const p = run().finally(() => pending.delete(key));
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pending.set(key, p);
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return p;
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};
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}
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