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- export class PromiseCache <A, R> {
- private readonly running = new Map<string, Promise<R>>()
- constructor (
- private readonly fn: (arg: A) => Promise<R>,
- private readonly keyBuilder: (arg: A) => string
- ) {
- }
- run (arg: A) {
- const key = this.keyBuilder(arg)
- if (this.running.has(key)) return this.running.get(key)
- const p = this.fn(arg)
- this.running.set(key, p)
- return p.finally(() => this.running.delete(key))
- }
- }
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