35 lines
1.2 KiB
TypeScript
35 lines
1.2 KiB
TypeScript
// ruthlessly stolen from @trunarla on twitter
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export class LRUCache {
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#cache: Map<string, string | Record<string, string | Record<string, string | boolean>>>;
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#capacity: number;
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constructor(capacity: number, cache: undefined | Map<string, string | Record<string, string | Record<string, string | boolean>>>) {
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this.#capacity = capacity;
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this.#cache = (cache) ? cache : new Map<string, string | Record<string, string | Record<string, string | boolean>>>();
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}
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set(key: string, value: string | Record<string, string | Record<string, string | boolean>>) {
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// If we're at capacity, we need to delete the least-recently-used item:
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if (this.#cache.size >= this.#capacity) {
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// Manually invoke the keys iterator to get the least-recently-used key:
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const keyToDelete = this.#cache.keys().next().value;
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this.#cache.delete(keyToDelete);
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}
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this.#cache.delete(key);
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this.#cache.set(key, value);
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}
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get(key: string): Record<string, string | Record<string, string | boolean>> | string | undefined {
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if (this.#cache.has(key)) {
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const value = this.#cache.get(key);
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if (!value) return;
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this.#cache.delete(key);
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this.#cache.set(key, value);
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return value;
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}
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}
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getCache() {
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return this.#cache;
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}
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} |