wehub-resource-sync
52 lines
1.1 KiB
JavaScript
52 lines
1.1 KiB
JavaScript
// LRU缓存类
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export default class Lru {
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constructor(max) {
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this.max = max || 1000
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this.size = 0
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this.pool = new Map()
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}
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add(key, value) {
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const isExist = this.has(key)
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// 如果该key之前不存在，并且现在数量已经超出最大值，则不再继续添加
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if (!isExist && this.size >= this.max) {
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return false
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}
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// 已经存在则可以更新，因为不影响数量
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// 如果该key是否已经存在，则先删除
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this.delete(key)
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// 添加
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this.pool.set(key, value)
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this.size++
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// 删除最早的没啥意义，详见：https://github.com/wanglin2/mind-map/issues/467
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// if (this.size > this.max) {
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// let keys = this.pool.keys()
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// let last = keys.next()
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// this.delete(last.value)
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// }
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return true
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}
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delete(key) {
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if (this.pool.has(key)) {
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this.pool.delete(key)
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this.size--
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}
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}
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has(key) {
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return this.pool.has(key)
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}
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get(key) {
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if (this.pool.has(key)) {
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return this.pool.get(key)
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}
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}
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clear() {
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this.size = 0
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this.pool = new Map()
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}
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}
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