docs/lib/warm-server.js

65 строки
2.3 KiB
JavaScript

import statsd from './statsd.js'
import { loadUnversionedTree, loadSiteTree, loadPages, loadPageMap } from './page-data.js'
import loadRedirects from './redirects/precompile.js'
// Instrument these functions so that
// it's wrapped in a timer that reports to Datadog
const dog = {
loadUnversionedTree: statsd.asyncTimer(loadUnversionedTree, 'load_unversioned_tree'),
loadSiteTree: statsd.asyncTimer(loadSiteTree, 'load_site_tree'),
loadPages: statsd.asyncTimer(loadPages, 'load_pages'),
loadPageMap: statsd.asyncTimer(loadPageMap, 'load_page_map'),
loadRedirects: statsd.asyncTimer(loadRedirects, 'load_redirects'),
}
// For multiple-triggered Promise sharing
let promisedWarmServer
async function warmServer() {
const startTime = Date.now()
if (process.env.NODE_ENV !== 'test') {
console.log('Priming context information...')
}
const unversionedTree = await dog.loadUnversionedTree()
const siteTree = await dog.loadSiteTree(unversionedTree)
const pageList = await dog.loadPages(unversionedTree)
const pageMap = await dog.loadPageMap(pageList)
const redirects = await dog.loadRedirects(pageList)
statsd.gauge('memory_heap_used', process.memoryUsage().heapUsed, ['event:warm-server'])
statsd.gauge('num_redirects', Object.keys(redirects).length)
statsd.gauge('num_page_map', Object.keys(pageMap).length)
statsd.gauge('num_page_list', Object.keys(pageList).length)
if (process.env.NODE_ENV !== 'test') {
console.log(`Context primed in ${Date.now() - startTime} ms`)
}
return {
pages: pageMap,
redirects,
unversionedTree,
siteTree,
pageList,
}
}
// Instrument the `warmServer` function so that
// it's wrapped in a timer that reports to Datadog
dog.warmServer = statsd.asyncTimer(warmServer, 'warm_server')
// We only want statistics if the priming needs to occur, so let's wrap the
// real method and return early [without statistics] whenever possible
export default async function warmServerWrapper() {
// Handle receiving multiple calls to this method from multiple page requests
// by holding the in-progress Promise and returning it instead of allowing
// the server to actually load all of the files multiple times.
if (!promisedWarmServer) {
promisedWarmServer = dog.warmServer()
}
return promisedWarmServer
}