1'use strict'
2
3const { LRUCache } = require('lru-cache')
4
5const MEMOIZED = new LRUCache({
6  max: 500,
7  maxSize: 50 * 1024 * 1024, // 50MB
8  ttl: 3 * 60 * 1000, // 3 minutes
9  sizeCalculation: (entry, key) => key.startsWith('key:') ? entry.data.length : entry.length,
10})
11
12module.exports.clearMemoized = clearMemoized
13
14function clearMemoized () {
15  const old = {}
16  MEMOIZED.forEach((v, k) => {
17    old[k] = v
18  })
19  MEMOIZED.clear()
20  return old
21}
22
23module.exports.put = put
24
25function put (cache, entry, data, opts) {
26  pickMem(opts).set(`key:${cache}:${entry.key}`, { entry, data })
27  putDigest(cache, entry.integrity, data, opts)
28}
29
30module.exports.put.byDigest = putDigest
31
32function putDigest (cache, integrity, data, opts) {
33  pickMem(opts).set(`digest:${cache}:${integrity}`, data)
34}
35
36module.exports.get = get
37
38function get (cache, key, opts) {
39  return pickMem(opts).get(`key:${cache}:${key}`)
40}
41
42module.exports.get.byDigest = getDigest
43
44function getDigest (cache, integrity, opts) {
45  return pickMem(opts).get(`digest:${cache}:${integrity}`)
46}
47
48class ObjProxy {
49  constructor (obj) {
50    this.obj = obj
51  }
52
53  get (key) {
54    return this.obj[key]
55  }
56
57  set (key, val) {
58    this.obj[key] = val
59  }
60}
61
62function pickMem (opts) {
63  if (!opts || !opts.memoize) {
64    return MEMOIZED
65  } else if (opts.memoize.get && opts.memoize.set) {
66    return opts.memoize
67  } else if (typeof opts.memoize === 'object') {
68    return new ObjProxy(opts.memoize)
69  } else {
70    return MEMOIZED
71  }
72}
73