38 lines
940 B
TypeScript
38 lines
940 B
TypeScript
// deno-lint-ignore-file ban-types
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import { LRUCache } from 'lru-cache';
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type FetchFn<K extends {}, V extends {}, O extends {}> = (key: K, opts: O) => Promise<V>;
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interface FetchFnOpts {
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signal?: AbortSignal | null;
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}
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export class SimpleLRU<
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K extends {},
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V extends {},
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O extends {} = FetchFnOpts,
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> {
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protected cache: LRUCache<K, V, void>;
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constructor(fetchFn: FetchFn<K, V, { signal: AbortSignal }>, opts: LRUCache.Options<K, V, void>) {
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this.cache = new LRUCache({
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fetchMethod: (key, _staleValue, { signal }) => fetchFn(key, { signal: signal as AbortSignal }),
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...opts,
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});
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}
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async fetch(key: K, opts?: O): Promise<V> {
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const result = await this.cache.fetch(key, opts);
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if (result === undefined) {
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throw new Error('SimpleLRU: fetch failed');
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}
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return result;
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}
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put(key: K, value: V): Promise<void> {
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this.cache.set(key, value);
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return Promise.resolve();
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}
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}
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