* first action! (#1)

node_modules/pacote/lib/fetchers/registry/packument.js

@@ -0,0 +1,92 @@
+'use strict'
+
+const BB = require('bluebird')
+
+const fetch = require('npm-registry-fetch')
+const LRU = require('lru-cache')
+const optCheck = require('../../util/opt-check')
+
+// Corgis are cute. 🐕🐶
+const CORGI_DOC = 'application/vnd.npm.install-v1+json; q=1.0, application/json; q=0.8, */*'
+const JSON_DOC = 'application/json'
+
+module.exports = packument
+function packument (spec, opts) {
+  opts = optCheck(opts)
+
+  const registry = fetch.pickRegistry(spec, opts)
+  const uri = registry.replace(/\/?$/, '/') + spec.escapedName
+
+  return fetchPackument(uri, registry, spec, opts)
+}
+
+const MEMO = new LRU({
+  length: m => m._contentLength,
+  max: 200 * 1024 * 1024, // 200MB
+  maxAge: 30 * 1000 // 30s
+})
+
+module.exports.clearMemoized = clearMemoized
+function clearMemoized () {
+  MEMO.reset()
+}
+
+function fetchPackument (uri, registry, spec, opts) {
+  const mem = pickMem(opts)
+  const accept = opts.fullMetadata ? JSON_DOC : CORGI_DOC
+  const memoKey = `${uri}~(${accept})`
+  if (mem && !opts.preferOnline && mem.has(memoKey)) {
+    return BB.resolve(mem.get(memoKey))
+  }
+
+  return fetch(uri, opts.concat({
+    headers: {
+      'pacote-req-type': 'packument',
+      'pacote-pkg-id': `registry:${spec.name}`,
+      accept
+    },
+    spec
+  }, opts, {
+    // Force integrity to null: we never check integrity hashes for manifests
+    integrity: null
+  })).then(res => res.json().then(packument => {
+    packument._cached = res.headers.has('x-local-cache')
+    packument._contentLength = +res.headers.get('content-length')
+    // NOTE - we need to call pickMem again because proxy
+    //        objects get reused!
+    const mem = pickMem(opts)
+    if (mem) {
+      mem.set(memoKey, packument)
+    }
+    return packument
+  })).catch(err => {
+    if (err.code === 'E404' && !opts.fullMetadata) {
+      return fetchPackument(uri, registry, spec, opts.concat({
+        fullMetadata: true
+      }))
+    } else {
+      throw err
+    }
+  })
+}
+
+class ObjProxy {
+  get (key) { return this.obj[key] }
+  set (key, val) { this.obj[key] = val }
+}
+
+// This object is used synchronously and immediately, so
+// we can safely reuse it instead of consing up new ones
+const PROX = new ObjProxy()
+function pickMem (opts) {
+  if (!opts || !opts.memoize) {
+    return MEMO
+  } else if (opts.memoize.get && opts.memoize.set) {
+    return opts.memoize
+  } else if (typeof opts.memoize === 'object') {
+    PROX.obj = opts.memoize
+    return PROX
+  } else {
+    return null
+  }
+}