More routes

assets/js/sw/bulk.ts

@@ -1,16 +1,8 @@
-/// <reference lib="WebWorker" />
-
+import { wait, json, u8Array } from 'utils/async';
 import { evenlyDivide } from 'utils/array';
 import { fetchBackoff } from 'utils/requests';
 import { Zip } from 'utils/zip';
 
-declare const self: ServiceWorkerGlobalScope;
-
-const wait = (ms: number): Promise<void> => new Promise(resolve => setTimeout(resolve, ms));
-const buffer = (blob: Blob) => blob.arrayBuffer().then(buf => new Uint8Array(buf));
-const json = (resp: Response) => resp.json();
-const blob = (resp: Response) => resp.blob();
-
 interface Image {
   id: number;
   name: string;
@@ -22,8 +14,8 @@ interface PageResult {
   total: number;
 }
 
-function handleStream(event: FetchEvent, url: URL): void {
-  const concurrency = parseInt(url.searchParams.get('concurrency') || '1', 5);
+export function handleBulk(event: FetchEvent, url: URL): void {
+  const concurrency = parseInt(url.searchParams.get('concurrency') || '1', 10);
   const queryString = url.searchParams.get('q');
   const failures = [];
   const zipper = new Zip();
@@ -39,18 +31,20 @@ function handleStream(event: FetchEvent, url: URL): void {
     pull(controller) {
       // Path to fetch next
       const nextQuery = encodeURIComponent(`(${queryString}),id.lte:${maxId}`);
+      const consumer = (buf: Uint8Array) => controller.enqueue(buf);
 
       return fetchBackoff(`/search/download?q=${nextQuery}`)
         .then(json)
         .then(({ images, total }: PageResult): Promise<void> => {
           if (total === 0) {
-            // Done, no results left
-            // Finalize zip and close stream to prevent any further pulls
-            return buffer(zipper.finalize())
-              .then(buf => {
-                controller.enqueue(buf);
+            // Finalize zip
+            zipper.finalize(consumer);
+
+            // Close stream
             controller.close();
-              });
+
+            // Done
+            return Promise.resolve();
           }
 
           // Decrease maximum ID for next round below current minimum
@@ -74,9 +68,8 @@ function handleStream(event: FetchEvent, url: URL): void {
         // eslint-disable-next-line camelcase
         for (const { name, view_url } of images) {
           promise = promise
-            .then(() => fetchBackoff(view_url)).then(blob).then(buffer)
-            .then(file => zipper.storeFile(name, file.buffer)).then(buffer)
-            .then(entry => controller.enqueue(entry))
+            .then(() => fetchBackoff(view_url).then(u8Array))
+            .then(file => zipper.storeFile(name, file.buffer, consumer))
             .catch(() => { failures.push(view_url); });
         }
 
@@ -92,15 +85,3 @@ function handleStream(event: FetchEvent, url: URL): void {
     }
   }));
 }
-
-self.addEventListener('fetch', event => {
-  const url = new URL(event.request.url);
-
-  // Streaming path
-  if (url.pathname === '/js/stream') return handleStream(event, url);
-
-  // Otherwise, not destined for us
-  return event.respondWith(fetch(event.request));
-});
-
-export default null;

assets/js/sw/download.ts

@@ -0,0 +1,29 @@
+import { escapeFilename, ifOk } from 'utils/requests';
+
+function allowedOrigin(target: string): boolean {
+  const selfUrl = new URL(self.location.toString());
+  const cdnHost = selfUrl.searchParams.get('cdn');
+
+  return new URL(target).hostname === cdnHost;
+}
+
+export function handleDownload(event: FetchEvent, url: URL): void {
+  const target = url.searchParams.get('target');
+  const name = url.searchParams.get('name');
+
+  if (!target || !name || !allowedOrigin(target)) {
+    return event.respondWith(new Response('Don\'t know what to download!', { status: 400 }));
+  }
+
+  const generateResponse = ifOk((upstream: Response) => {
+    const headers = new Headers(upstream.headers);
+
+    headers.set('content-disposition', `attachment; filename="${escapeFilename(name)}"`);
+
+    return new Response(upstream.body, { headers });
+  });
+
+  fetch(target)
+    .then(generateResponse)
+    .then(event.respondWith);
+}

assets/js/sw/tsconfig.json

@@ -0,0 +1,7 @@
+{
+    "extends": "../../tsconfig",
+    "compilerOptions": {
+        "lib": ["WebWorker"]
+    },
+    "include": ["*.ts"]
+}

assets/js/sw/worker.ts

@@ -0,0 +1,18 @@
+import { handleBulk } from './bulk';
+import { handleDownload } from './download';
+
+// Declarations for TypeScript
+declare const self: ServiceWorkerGlobalScope;
+export default null;
+
+/**
+ * Performs routing under the ServiceWorker path scope.
+ */
+self.addEventListener('fetch', event => {
+  const url = new URL(event.request.url);
+
+  if (url.pathname === '/js/stream') return handleBulk(event, url);
+  if (url.pathname === '/js/download') return handleDownload(event, url);
+
+  return event.respondWith(fetch(event.request));
+});

assets/js/utils/async.ts

@@ -0,0 +1,17 @@
+/*
+ * Miscellaneous utilities for asynchronous code.
+ */
+
+export function wait(ms: number): Promise<void> {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+
+export function json(resp: Response): Promise<any> {
+  return resp.json();
+}
+
+export function u8Array(resp: Response): Promise<Uint8Array> {
+  return resp
+    .arrayBuffer()
+    .then(buf => new Uint8Array(buf));
+}

assets/js/utils/requests.js

@@ -2,6 +2,8 @@
  * Request Utils
  */
 
+import { wait } from './async';
+
 function fetchJson(verb, endpoint, body) {
   const data = {
     method: verb,
@@ -52,13 +54,37 @@ function fetchBackoff(...fetchArgs) {
     return fetch(...fetchArgs)
       .then(handleError)
       .catch(() =>
-        new Promise(resolve =>
-          setTimeout(() => resolve(fetchBackoffTimeout(newTimeout)), timeout)
-        )
+        wait(timeout).then(fetchBackoffTimeout(newTimeout))
       );
   }
 
   return fetchBackoffTimeout(5000);
 }
 
-export { fetchJson, fetchHtml, fetchBackoff, handleError };
+/**
+ * Escape a filename for inclusion in a Content-Disposition
+ * response header.
+ *
+ * @param {string} name
+ * @returns {string}
+ */
+function escapeFilename(name) {
+  return name
+    .replace(/[^-_+a-zA-Z0-9]/, '_')
+    .substring(0, 150);
+}
+
+/**
+ * Run the wrapped function if the response was okay,
+ * otherwise return the response.
+ * @param {(_: Response) => Response} responseGenerator
+ * @returns {(_: Response) => Response}
+ */
+function ifOk(responseGenerator) {
+  return resp => {
+    if (resp.ok) return new Response(responseGenerator(resp));
+    return resp;
+  };
+}
+
+export { fetchJson, fetchHtml, fetchBackoff, handleError, escapeFilename, ifOk };

assets/js/utils/zip.ts

@@ -1,5 +1,8 @@
 import { crc32, asciiEncode, serialize } from './binary';
 
+// eslint-disable-next-line no-unused-vars
+type U8Consumer = (_: Uint8Array) => void;
+
 interface FileInfo {
     headerOffset: number;
     byteLength: number;
@@ -18,7 +21,7 @@ export class Zip {
       this.offset = 0;
     }
 
-    storeFile(name: string, file: ArrayBuffer): Blob {
+    storeFile(name: string, file: ArrayBuffer, consumer: U8Consumer): void {
       const crc = crc32(file);
       const ns = asciiEncode(name);
 
@@ -51,11 +54,14 @@ export class Zip {
       ]);
 
       this.offset += header.byteLength + ns.byteLength + localField.byteLength + file.byteLength;
-      return new Blob([header, ns, localField, file]);
+
+      consumer(new Uint8Array(header));
+      consumer(new Uint8Array(ns));
+      consumer(new Uint8Array(localField));
+      consumer(new Uint8Array(file));
     }
 
-    finalize(): Blob {
-      const segments = [];
+    finalize(consumer: U8Consumer): void {
       const cdOff = this.offset;
       let numFiles = 0;
 
@@ -91,7 +97,10 @@ export class Zip {
         ]);
 
         this.offset += cdEntry.byteLength + info.name.byteLength + cdField.byteLength;
-        segments.push(cdEntry, info.name, cdField);
+
+        consumer(new Uint8Array(cdEntry));
+        consumer(new Uint8Array(info.name));
+        consumer(new Uint8Array(cdField));
 
         numFiles++;
       }
@@ -129,8 +138,9 @@ export class Zip {
       ]);
 
       this.offset += endCd64.byteLength + endLoc64.byteLength + endCd.byteLength;
-      segments.push(endCd64, endLoc64, endCd);
 
-      return new Blob(segments);
+      consumer(new Uint8Array(endCd64));
+      consumer(new Uint8Array(endLoc64));
+      consumer(new Uint8Array(endCd));
     }
 }

assets/webpack.config.js

@@ -60,7 +60,7 @@ module.exports = {
   mode: isDevelopment ? 'development' : 'production',
   entry: {
     'js/app.js': './js/app.js',
-    'js/worker.js': './js/worker.ts',
+    'js/worker.js': './js/sw/worker.ts',
     ...themes
   },
   output: {

lib/philomena_web/views/layout_view.ex

@@ -53,7 +53,7 @@ defmodule PhilomenaWeb.LayoutView do
       interactions: Jason.encode!(interactions),
       ignored_tag_list: Jason.encode!(ignored_tag_list(conn.assigns[:tags])),
       hide_staff_tools: conn.cookies["hide_staff_tools"],
-      worker_path: Routes.static_path(conn, "/js/worker.js")
+      worker_path: Routes.static_path(conn, "/js/worker.js") <> "?cdn=" <> cdn_host()
     ]
 
     data = Keyword.merge(data, extra)