codekingpro/portable-devtools

1'use strict'
2
3class LRUCache {
4  constructor () {
5    this.max = 1000
6    this.map = new Map()
7  }
8
9  get (key) {
10    const value = this.map.get(key)
11    if (value === undefined) {
12      return undefined
13    } else {
14      // Remove the key from the map and add it to the end
15      this.map.delete(key)
16      this.map.set(key, value)
17      return value
18    }
19  }
20
21  delete (key) {
22    return this.map.delete(key)
23  }
24
25  set (key, value) {
26    const deleted = this.delete(key)
27
28    if (!deleted && value !== undefined) {
29      // If cache is full, delete the least recently used item
30      if (this.map.size >= this.max) {
31        const firstKey = this.map.keys().next().value
32        this.delete(firstKey)
33      }
34
35      this.map.set(key, value)
36    }
37
38    return this
39  }
40}
41
42module.exports = LRUCache
43