Revert file reads from async to sync (#16979)

* Revert file reads from async to sync

* Async funness

* Fix warm server timers

Co-authored-by: Chiedo John <chiedo@chiedosbmacbook.lan>

Author: heiskr

lib/data-directory.js

@@ -1,15 +1,12 @@
 const assert = require('assert')
-const fs = require('fs').promises
+const fs = require('fs')
 const path = require('path')
 const walk = require('walk-sync')
-const { mapLimit } = require('async')
 const yaml = require('js-yaml')
 const { isRegExp, set } = require('lodash')
 const filenameToKey = require('./filename-to-key')
 
-const FILE_READ_LIMIT = 100
-
-module.exports = async function dataDirectory (dir, opts = {}) {
+module.exports = function dataDirectory (dir, opts = {}) {
   const defaultOpts = {
     preprocess: (content) => { return content },
     ignorePatterns: [/README\.md$/i],
@@ -42,10 +39,9 @@ module.exports = async function dataDirectory (dir, opts = {}) {
       // ignore files that don't have a whitelisted file extension
       return opts.extensions.includes(path.extname(filename).toLowerCase())
     })
-  const files = await mapLimit(
-    filenames,
-    FILE_READ_LIMIT,
-    async filename => [filename, await fs.readFile(filename, 'utf8')]
+
+  const files = filenames.map(
+    filename => [filename, fs.readFileSync(filename, 'utf8')]
   )
   files.forEach(([filename, fileContent]) => {
     // derive `foo.bar.baz` object key from `foo/bar/baz.yml` filename

lib/page.js

@@ -1,5 +1,5 @@
 const assert = require('assert')
-const fs = require('fs').promises
+const fs = require('fs')
 const path = require('path')
 const cheerio = require('cheerio')
 const patterns = require('./patterns')
@@ -23,13 +23,13 @@ const slash = require('slash')
 const statsd = require('./statsd')
 
 class Page {
-  static async init (opts) {
-    opts = await Page.read(opts)
+  static init (opts) {
+    opts = Page.read(opts)
     if (!opts) return
     return new Page(opts)
   }
 
-  static async read (opts) {
+  static read (opts) {
     assert(opts.relativePath, 'relativePath is required')
     assert(opts.basePath, 'basePath is required')
 
@@ -39,7 +39,7 @@ class Page {
     // Per https://nodejs.org/api/fs.html#fs_fs_exists_path_callback
     // its better to read and handle errors than to check access/stats first
     try {
-      const raw = await fs.readFile(fullPath, 'utf8')
+      const raw = fs.readFileSync(fullPath, 'utf8')
       return { ...opts, relativePath, fullPath, raw }
     } catch (err) {
       if (err.code === 'ENOENT') return false

lib/pages.js

@@ -2,21 +2,16 @@ const path = require('path')
 const walk = require('walk-sync').entries
 const Page = require('./page')
 const languages = require('./languages')
-const { mapLimit } = require('async')
 
-const FILE_READ_LIMIT = 100
-
-async function loadPageList () {
+function loadPageList () {
   // load english pages
   const englishPath = path.join(__dirname, '..', languages.en.dir, 'content')
   const englishPaths = walk(englishPath, {
     globs: ['**/*.md'],
     ignore: ['**/README.md']
   })
-  const englishPages = await mapLimit(
-    englishPaths,
-    FILE_READ_LIMIT,
-    async opts => await Page.read({
+  const englishPages = englishPaths.map(
+    opts => Page.read({
       ...opts,
       languageCode: languages.en.code
     })
@@ -34,11 +29,10 @@ async function loadPageList () {
       }))
     })
     .flat()
-  const localizedPages = await mapLimit(
-    localizedPaths,
-    FILE_READ_LIMIT,
-    async ({ basePath, relativePath, languageCode }) =>
-      await Page.read({ basePath, relativePath, languageCode })
+
+  const localizedPages = localizedPaths.map(
+    ({ basePath, relativePath, languageCode }) =>
+      Page.read({ basePath, relativePath, languageCode })
   )
 
   // Build out the list of prepared pages
@@ -64,8 +58,8 @@ function createMapFromArray (pageList) {
   return pageMap
 }
 
-async function loadPageMap (pageList) {
-  const pages = pageList || await loadPageList()
+function loadPageMap (pageList) {
+  const pages = pageList || loadPageList()
   return createMapFromArray(pages)
 }
 

lib/warm-server.js

@@ -7,10 +7,10 @@ const loadSiteTree = require('./site-tree')
 // Instrument these functions so that
 // it's wrapped in a timer that reports to Datadog
 const dog = {
-  loadPages: statsd.asyncTimer(loadPages, 'load_pages'),
-  loadPageMap: statsd.asyncTimer(loadPageMap, 'load_page_map'),
+  loadPages: statsd.timer(loadPages, 'load_pages'),
+  loadPageMap: statsd.timer(loadPageMap, 'load_page_map'),
   loadRedirects: statsd.asyncTimer(loadRedirects, 'load_redirects'),
-  loadSiteData: statsd.asyncTimer(loadSiteData, 'load_site_data'),
+  loadSiteData: statsd.timer(loadSiteData, 'load_site_data'),
   loadSiteTree: statsd.asyncTimer(loadSiteTree, 'load_site_tree')
 }
 

package-lock.json

@@ -26,7 +26,6 @@
     "@primer/css": "^15.1.0",
     "@primer/octicons": "^11.0.0",
     "algoliasearch": "^3.35.1",
-    "async": "^3.2.0",
     "babel-loader": "^8.1.0",
     "babel-preset-env": "^1.7.0",
     "browser-date-formatter": "^3.0.3",
@@ -95,6 +94,7 @@
   "devDependencies": {
     "@actions/core": "^1.2.6",
     "ajv": "^6.11.0",
+    "async": "^3.2.0",
     "await-sleep": "0.0.1",
     "aws-sdk": "^2.610.0",
     "babel-eslint": "^10.1.0",