2018-04-17 14:57:09 +02:00

515 lines
14 KiB
TypeScript

// pack:ignore
// This is the service worker for notify.moe.
// When installed, it will intercept all requests made by the browser
// and return a cache-first response.
// request request
// Browser -------> Service Worker ------> notify.moe Server
// <-------
// response (cache)
// <------
// response (network)
// <-------
// response (network)
//
// -> Diff cache with network response.
// By always returning cache first,
// we avoid latency problems on high latency connections like mobile
// networks. While the cache is being served, we start a real network
// request to the server to see if the resource changed. We compare the
// E-Tag of the cached and latest version of the resource. If the E-Tag
// of the current document changed, we send a message to the client
// that will cause the client to reload (diff) the page. It is not a real
// page reload as we will only calculate a DOM diff on the contents.
// If the style or script resources changed after being served, we need
// to force a real page reload.
// Promises
const CACHEREFRESH = new Map<string, Promise<void>>()
// E-Tags that we served for a given URL
const ETAGS = new Map<string, string>()
// When these patterns are matched for the request URL, we exclude them from being
// served cache-first and instead serve them via a network request.
// Note that the service worker URL is automatically excluded from fetch events
// and therefore doesn't need to be added here.
const EXCLUDECACHE = new Set<string>([
// API requests
"/api/",
// PayPal stuff
"/paypal/",
// List imports
"/import/",
// Infinite scrolling
"/from/",
// Chrome extension
"chrome-extension",
// Authorization paths /auth/ and /logout are not listed here because they are handled in a special way.
])
// MyServiceWorker is the process that controls all the tabs in a browser.
class MyServiceWorker {
cache: MyCache
reloads: Map<string, Promise<Response>>
constructor() {
this.cache = new MyCache("v-6")
this.reloads = new Map<string, Promise<Response>>()
self.addEventListener("install", (evt: InstallEvent) => evt.waitUntil(this.onInstall(evt)))
self.addEventListener("activate", (evt: any) => evt.waitUntil(this.onActivate(evt)))
self.addEventListener("fetch", (evt: FetchEvent) => evt.waitUntil(this.onRequest(evt)))
self.addEventListener("message", (evt: any) => evt.waitUntil(this.onMessage(evt)))
self.addEventListener("push", (evt: PushEvent) => evt.waitUntil(this.onPush(evt)))
self.addEventListener("pushsubscriptionchange", (evt: any) => evt.waitUntil(this.onPushSubscriptionChange(evt)))
self.addEventListener("notificationclick", (evt: NotificationEvent) => evt.waitUntil(this.onNotificationClick(evt)))
}
onInstall(evt: InstallEvent) {
console.log("service worker install")
return self.skipWaiting().then(() => {
return this.installCache()
})
}
onActivate(evt: any) {
console.log("service worker activate")
// Only keep current version of the cache and delete old caches
let cacheWhitelist = [this.cache.version]
let deleteOldCache = caches.keys().then(keyList => {
return Promise.all(keyList.map(key => {
if(cacheWhitelist.indexOf(key) === -1) {
return caches.delete(key)
}
}))
})
// Immediate claim helps us gain control over a new client immediately
let immediateClaim = self.clients.claim()
return Promise.all([
deleteOldCache,
immediateClaim
])
}
// onRequest intercepts all browser requests
onRequest(evt: FetchEvent) {
// Allow XHR upload requests via POST,
// so that we can receive upload progress events.
if(evt.request.method === "POST") {
return
}
// Fetch via network
return evt.respondWith(fetch(evt.request))
// let request = evt.request as Request
// // If it's not a GET request, fetch it normally
// if(request.method !== "GET") {
// return evt.respondWith(this.fromNetwork(request))
// }
// // Clear cache on authentication and fetch it normally
// if(request.url.includes("/auth/") || request.url.includes("/logout")) {
// return evt.respondWith(caches.delete(this.cache.version).then(() => fetch(request)))
// }
// // Exclude certain URLs from being cached
// for(let pattern of EXCLUDECACHE.keys()) {
// if(request.url.includes(pattern)) {
// return evt.respondWith(this.fromNetwork(request))
// }
// }
// // If the request included the header "X-CacheOnly", return a cache-only response.
// // This is used in reloads to avoid generating a 2nd request after a cache refresh.
// if(request.headers.get("X-CacheOnly") === "true") {
// return evt.respondWith(this.fromCache(request))
// }
// // Save the served E-Tag when onResponse is called
// let servedETag = undefined
// let onResponse = (response: Response | null) => {
// if(response) {
// servedETag = response.headers.get("ETag")
// ETAGS.set(request.url, servedETag)
// }
// return response
// }
// let saveResponseInCache = response => {
// let clone = response.clone()
// // Save the new version of the resource in the cache
// let cacheRefresh = this.cache.store(request, clone).catch(err => {
// console.error(err)
// // TODO: Tell client that the quota is exceeded (disk full).
// })
// CACHEREFRESH.set(request.url, cacheRefresh)
// return response
// }
// // Start fetching the request
// let network =
// fetch(request)
// .then(saveResponseInCache)
// .catch(error => {
// console.log("Fetch error:", error)
// throw error
// })
// // Save in map
// this.reloads.set(request.url, network)
// if(request.headers.get("X-Reload") === "true") {
// return evt.respondWith(network)
// }
// // Scripts and styles are server pushed on the initial response
// // so we can use a network-first response without an additional round-trip.
// // This causes the browser to always load the most recent scripts and styles.
// if(request.url.endsWith("/styles") || request.url.endsWith("/scripts")) {
// return evt.respondWith(this.networkFirst(request, network, onResponse))
// }
// return evt.respondWith(this.cacheFirst(request, network, onResponse))
}
// onMessage is called when the service worker receives a message from a client (browser tab).
async onMessage(evt: ServiceWorkerMessageEvent) {
let message = JSON.parse(evt.data)
let clientId = (evt.source as any).id
let client = await MyClient.get(clientId)
client.onMessage(message)
}
// onPush is called on push events and requires the payload to contain JSON information about the notification.
onPush(evt: PushEvent) {
var payload = evt.data ? evt.data.json() : {}
// Notify all clients about the new notification so they can update their notification counter
this.broadcast({
type: "new notification"
})
// Display the notification
return self.registration.showNotification(payload.title, {
body: payload.message,
icon: payload.icon,
data: payload.link,
badge: "https://media.notify.moe/images/brand/64.png"
})
}
onPushSubscriptionChange(evt: any) {
return self.registration.pushManager.subscribe(evt.oldSubscription.options)
.then(async subscription => {
console.log("send subscription to server...")
let rawKey = subscription.getKey("p256dh")
let key = rawKey ? btoa(String.fromCharCode.apply(null, new Uint8Array(rawKey))) : ""
let rawSecret = subscription.getKey("auth")
let secret = rawSecret ? btoa(String.fromCharCode.apply(null, new Uint8Array(rawSecret))) : ""
let endpoint = subscription.endpoint
let pushSubscription = {
endpoint,
p256dh: key,
auth: secret,
platform: navigator.platform,
userAgent: navigator.userAgent,
screen: {
width: window.screen.width,
height: window.screen.height
}
}
let user = await fetch("/api/me", {
credentials: "same-origin"
}).then(response => response.json())
return fetch("/api/pushsubscriptions/" + user.id + "/add", {
method: "POST",
credentials: "same-origin",
body: JSON.stringify(pushSubscription)
})
})
}
// onNotificationClick is called when the user clicks on a notification.
onNotificationClick(evt: NotificationEvent) {
let notification = evt.notification
notification.close()
return self.clients.matchAll().then(function(clientList) {
// If we have a link, use that link to open a new window.
let url = notification.data
if(url) {
return self.clients.openWindow(url)
}
// If there is at least one client, focus it.
if(clientList.length > 0) {
return (clientList[0] as WindowClient).focus()
}
// Otherwise open a new window
return self.clients.openWindow("https://notify.moe")
})
}
// Broadcast sends a message to all clients (open tabs etc.)
broadcast(msg: object) {
const msgText = JSON.stringify(msg)
self.clients.matchAll().then(function(clientList) {
for(let client of clientList) {
client.postMessage(msgText)
}
})
}
// installCache is called when the service worker is installed for the first time.
installCache() {
return caches.open(this.cache.version).then(cache => {
return cache.addAll([
"./scripts",
"./styles",
])
})
}
// Serve network first.
// Fall back to cache.
async networkFirst(request: Request, network: Promise<Response>, onResponse: (r: Response) => Response): Promise<Response> {
let response: Response | null
try {
response = await network
console.log("Network HIT:", request.url)
} catch(error) {
console.log("Network MISS:", request.url, error)
try {
response = await this.fromCache(request)
} catch(error) {
console.error(error)
}
}
return onResponse(response)
}
// Serve cache first.
// Fall back to network.
async cacheFirst(request: Request, network: Promise<Response>, onResponse: (r: Response) => Response): Promise<Response> {
let response: Response | null
try {
response = await this.fromCache(request)
console.log("Cache HIT:", request.url)
} catch(error) {
console.log("Cache MISS:", request.url, error)
try {
response = await network
} catch(error) {
console.error(error)
}
}
return onResponse(response)
}
fromCache(request): Promise<Response> {
return caches.open(this.cache.version).then(cache => {
return cache.match(request).then(matching => {
if(matching) {
return Promise.resolve(matching)
}
return Promise.reject("no-match")
})
})
}
}
// MyCache is the cache used by the service worker.
class MyCache {
version: string
constructor(version: string) {
this.version = version
}
store(request: RequestInfo, response: Response) {
return caches.open(this.version).then(cache => {
// This can fail if the disk space quota has been exceeded.
return cache.put(request, response)
})
}
}
// MyClient represents a single tab in the browser.
class MyClient {
client: ServiceWorkerClient
constructor(client: ServiceWorkerClient) {
this.client = client
}
onMessage(message: any) {
switch(message.type) {
case "loaded":
this.onDOMContentLoaded(message.url)
break
case "broadcast":
message.type = message.realType
delete message.realType
serviceWorker.broadcast(message)
break
}
}
postMessage(message: object) {
this.client.postMessage(JSON.stringify(message))
}
// onDOMContentLoaded is called when the client sent this service worker
// a message that the page has been loaded.
onDOMContentLoaded(url: string) {
// let refresh = serviceWorker.reloads.get(url)
// let servedETag = ETAGS.get(url)
// // If the user requests a sub-page we should prefetch the full page, too.
// if(url.includes("/_/") && !url.includes("/_/search/")) {
// var prefetch = true
// for(let pattern of EXCLUDECACHE.keys()) {
// if(url.includes(pattern)) {
// prefetch = false
// break
// }
// }
// if(prefetch) {
// this.prefetchFullPage(url)
// }
// }
// if(!refresh || !servedETag) {
// return Promise.resolve()
// }
// return refresh.then(async (response: Response) => {
// // When the actual network request was used by the client, response.bodyUsed is set.
// // In that case the client is already up to date and we don"t need to tell the client to do a refresh.
// if(response.bodyUsed) {
// return
// }
// // Get the ETag of the cached response we sent to the client earlier.
// let eTag = response.headers.get("ETag")
// // Update ETag
// ETAGS.set(url, eTag)
// // If the ETag changed, we need to do a reload.
// if(eTag !== servedETag) {
// return this.reloadContent(url)
// }
// // Do nothing
// return Promise.resolve()
// })
}
// prefetchFullPage(url: string) {
// let fullPage = new Request(url.replace("/_/", "/"))
// let fullPageRefresh = fetch(fullPage, {
// credentials: "same-origin"
// }).then(response => {
// // Save the new version of the resource in the cache
// let cacheRefresh = caches.open(serviceWorker.cache.version).then(cache => {
// return cache.put(fullPage, response)
// })
// CACHEREFRESH.set(fullPage.url, cacheRefresh)
// return response
// })
// // Save in map
// serviceWorker.reloads.set(fullPage.url, fullPageRefresh)
// }
// async reloadContent(url: string) {
// let cacheRefresh = CACHEREFRESH.get(url)
// if(cacheRefresh) {
// await cacheRefresh
// }
// return this.postMessage({
// type: "new content",
// url
// })
// }
// async reloadPage(url: string) {
// let networkFetch = serviceWorker.reloads.get(url.replace("/_/", "/"))
// if(networkFetch) {
// await networkFetch
// }
// return this.postMessage({
// type: "reload page",
// url
// })
// }
// reloadStyles() {
// return this.postMessage({
// type: "reload styles"
// })
// }
// Map of clients
static idToClient = new Map<string, MyClient>()
static async get(id: string): Promise<MyClient> {
let client = MyClient.idToClient.get(id)
if(!client) {
client = new MyClient(await self.clients.get(id))
MyClient.idToClient.set(id, client)
}
return client
}
}
const serviceWorker = new MyServiceWorker()