58 lines
1.1 KiB
JavaScript
58 lines
1.1 KiB
JavaScript
/*
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* Copyright (c) 2010-2018 Tim Düsterhus.
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*
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* Use of this software is governed by the Business Source License
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* included in the LICENSE file.
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*
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* Change Date: 2024-11-01
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*
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* On the date above, in accordance with the Business Source
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* License, use of this software will be governed by version 2
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* or later of the General Public License.
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*/
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define([], function () {
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'use strict'
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const s = Symbol('s')
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const start = Symbol('start')
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class LRU {
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constructor() {
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this[s] = new Map()
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this[start] = undefined
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}
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add(value) {
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if (this[start] && this[start].value === value) {
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return
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}
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if (this[s].has(value)) {
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const entry = this[s].get(value)
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if (entry.prev) {
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entry.prev.next = entry.next
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}
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if (entry.next) {
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entry.next.prev = entry.prev
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}
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}
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const obj = { value, next: this[start], prev: undefined }
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this[start] = obj
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if (this[start].next) {
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this[start].next.prev = obj
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}
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this[s].set(value, obj)
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}
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*[Symbol.iterator]() {
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let current = this[start]
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do {
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yield current.value
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} while ((current = current.next))
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}
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}
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return LRU
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})
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