Index: node_modules/cacache/lib/memoization.js
===================================================================
--- node_modules/cacache/lib/memoization.js	(revision 81bc7da776d8cda42939ef4ab350c88d13b4941f)
+++ node_modules/cacache/lib/memoization.js	(revision 81bc7da776d8cda42939ef4ab350c88d13b4941f)
@@ -0,0 +1,73 @@
+'use strict'
+
+const LRU = require('lru-cache')
+
+const MAX_SIZE = 50 * 1024 * 1024 // 50MB
+const MAX_AGE = 3 * 60 * 1000
+
+const MEMOIZED = new LRU({
+  max: MAX_SIZE,
+  maxAge: MAX_AGE,
+  length: (entry, key) => key.startsWith('key:') ? entry.data.length : entry.length,
+})
+
+module.exports.clearMemoized = clearMemoized
+
+function clearMemoized () {
+  const old = {}
+  MEMOIZED.forEach((v, k) => {
+    old[k] = v
+  })
+  MEMOIZED.reset()
+  return old
+}
+
+module.exports.put = put
+
+function put (cache, entry, data, opts) {
+  pickMem(opts).set(`key:${cache}:${entry.key}`, { entry, data })
+  putDigest(cache, entry.integrity, data, opts)
+}
+
+module.exports.put.byDigest = putDigest
+
+function putDigest (cache, integrity, data, opts) {
+  pickMem(opts).set(`digest:${cache}:${integrity}`, data)
+}
+
+module.exports.get = get
+
+function get (cache, key, opts) {
+  return pickMem(opts).get(`key:${cache}:${key}`)
+}
+
+module.exports.get.byDigest = getDigest
+
+function getDigest (cache, integrity, opts) {
+  return pickMem(opts).get(`digest:${cache}:${integrity}`)
+}
+
+class ObjProxy {
+  constructor (obj) {
+    this.obj = obj
+  }
+
+  get (key) {
+    return this.obj[key]
+  }
+
+  set (key, val) {
+    this.obj[key] = val
+  }
+}
+
+function pickMem (opts) {
+  if (!opts || !opts.memoize)
+    return MEMOIZED
+  else if (opts.memoize.get && opts.memoize.set)
+    return opts.memoize
+  else if (typeof opts.memoize === 'object')
+    return new ObjProxy(opts.memoize)
+  else
+    return MEMOIZED
+}