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- 'use strict';
- class QuickLRU {
- constructor(options = {}) {
- if (!(options.maxSize && options.maxSize > 0)) {
- throw new TypeError('`maxSize` must be a number greater than 0');
- }
- this.maxSize = options.maxSize;
- this.cache = new Map();
- this.oldCache = new Map();
- this._size = 0;
- }
- _set(key, value) {
- this.cache.set(key, value);
- this._size++;
- if (this._size >= this.maxSize) {
- this._size = 0;
- this.oldCache = this.cache;
- this.cache = new Map();
- }
- }
- get(key) {
- if (this.cache.has(key)) {
- return this.cache.get(key);
- }
- if (this.oldCache.has(key)) {
- const value = this.oldCache.get(key);
- this.oldCache.delete(key);
- this._set(key, value);
- return value;
- }
- }
- set(key, value) {
- if (this.cache.has(key)) {
- this.cache.set(key, value);
- } else {
- this._set(key, value);
- }
- return this;
- }
- has(key) {
- return this.cache.has(key) || this.oldCache.has(key);
- }
- peek(key) {
- if (this.cache.has(key)) {
- return this.cache.get(key);
- }
- if (this.oldCache.has(key)) {
- return this.oldCache.get(key);
- }
- }
- delete(key) {
- const deleted = this.cache.delete(key);
- if (deleted) {
- this._size--;
- }
- return this.oldCache.delete(key) || deleted;
- }
- clear() {
- this.cache.clear();
- this.oldCache.clear();
- this._size = 0;
- }
- * keys() {
- for (const [key] of this) {
- yield key;
- }
- }
- * values() {
- for (const [, value] of this) {
- yield value;
- }
- }
- * [Symbol.iterator]() {
- for (const item of this.cache) {
- yield item;
- }
- for (const item of this.oldCache) {
- const [key] = item;
- if (!this.cache.has(key)) {
- yield item;
- }
- }
- }
- get size() {
- let oldCacheSize = 0;
- for (const key of this.oldCache.keys()) {
- if (!this.cache.has(key)) {
- oldCacheSize++;
- }
- }
- return this._size + oldCacheSize;
- }
- }
- module.exports = QuickLRU;
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