a few changes to make A/B testing easier

app/fileManager.js

@@ -0,0 +1,202 @@
+/* global EXPIRE_SECONDS */
+import FileSender from './fileSender';
+import FileReceiver from './fileReceiver';
+import { copyToClipboard, delay, fadeOut } from './utils';
+import * as metrics from './metrics';
+
+function saveFile(file) {
+  const dataView = new DataView(file.plaintext);
+  const blob = new Blob([dataView], { type: file.type });
+  const downloadUrl = URL.createObjectURL(blob);
+
+  if (window.navigator.msSaveBlob) {
+    return window.navigator.msSaveBlob(blob, file.name);
+  }
+  const a = document.createElement('a');
+  a.href = downloadUrl;
+  a.download = file.name;
+  document.body.appendChild(a);
+  a.click();
+  URL.revokeObjectURL(downloadUrl);
+}
+
+function openLinksInNewTab(links, should = true) {
+  links = links || Array.from(document.querySelectorAll('a:not([target])'));
+  if (should) {
+    links.forEach(l => {
+      l.setAttribute('target', '_blank');
+      l.setAttribute('rel', 'noopener noreferrer');
+    });
+  } else {
+    links.forEach(l => {
+      l.removeAttribute('target');
+      l.removeAttribute('rel');
+    });
+  }
+  return links;
+}
+
+function exists(id) {
+  return new Promise((resolve, reject) => {
+    const xhr = new XMLHttpRequest();
+    xhr.onreadystatechange = () => {
+      if (xhr.readyState === XMLHttpRequest.HEADERS_RECEIVED) {
+        resolve(xhr.status === 200);
+      }
+    };
+    xhr.onerror = () => resolve(false);
+    xhr.ontimeout = () => resolve(false);
+    xhr.open('get', '/api/exists/' + id);
+    xhr.timeout = 2000;
+    xhr.send();
+  });
+}
+
+export default function(state, emitter) {
+  let lastRender = 0;
+
+  function render() {
+    emitter.emit('render');
+  }
+
+  async function checkFiles() {
+    const files = state.storage.files;
+    let rerender = false;
+    for (const file of files) {
+      const ok = await exists(file.id);
+      if (!ok) {
+        state.storage.remove(file.id);
+        rerender = true;
+      }
+    }
+    if (rerender) {
+      render();
+    }
+  }
+
+  emitter.on('DOMContentLoaded', checkFiles);
+
+  emitter.on('navigate', checkFiles);
+
+  emitter.on('render', () => {
+    lastRender = Date.now();
+  });
+
+  emitter.on('delete', async ({ file, location }) => {
+    try {
+      metrics.deletedUpload({
+        size: file.size,
+        time: file.time,
+        speed: file.speed,
+        type: file.type,
+        ttl: file.expiresAt - Date.now(),
+        location
+      });
+      state.storage.remove(file.id);
+      await FileSender.delete(file.id, file.deleteToken);
+    } catch (e) {
+      state.raven.captureException(e);
+    }
+    state.fileInfo = null;
+  });
+
+  emitter.on('cancel', () => {
+    state.transfer.cancel();
+  });
+
+  emitter.on('upload', async ({ file, type }) => {
+    const size = file.size;
+    const sender = new FileSender(file);
+    sender.on('progress', render);
+    sender.on('encrypting', render);
+    state.transfer = sender;
+    render();
+    const links = openLinksInNewTab();
+    await delay(200);
+    try {
+      const start = Date.now();
+      metrics.startedUpload({ size, type });
+      const info = await sender.upload();
+      const time = Date.now() - start;
+      const speed = size / (time / 1000);
+      metrics.completedUpload({ size, time, speed, type });
+      await delay(1000);
+      await fadeOut('upload-progress');
+      info.name = file.name;
+      info.size = size;
+      info.type = type;
+      info.time = time;
+      info.speed = speed;
+      info.createdAt = Date.now();
+      info.url = `${info.url}#${info.secretKey}`;
+      info.expiresAt = Date.now() + EXPIRE_SECONDS * 1000;
+      state.fileInfo = info;
+      state.storage.addFile(state.fileInfo);
+      openLinksInNewTab(links, false);
+      state.transfer = null;
+      state.storage.totalUploads += 1;
+      emitter.emit('pushState', `/share/${info.id}`);
+    } catch (err) {
+      state.transfer = null;
+      if (err.message === '0') {
+        //cancelled. do nothing
+        metrics.cancelledUpload({ size, type });
+        return render();
+      }
+      state.raven.captureException(err);
+      metrics.stoppedUpload({ size, type, err });
+      emitter.emit('replaceState', '/error');
+    }
+  });
+
+  emitter.on('download', async file => {
+    const size = file.size;
+    const url = `/api/download/${file.id}`;
+    const receiver = new FileReceiver(url, file.key);
+    receiver.on('progress', render);
+    receiver.on('decrypting', render);
+    state.transfer = receiver;
+    const links = openLinksInNewTab();
+    render();
+    try {
+      const start = Date.now();
+      metrics.startedDownload({ size: file.size, ttl: file.ttl });
+      const f = await receiver.download();
+      const time = Date.now() - start;
+      const speed = size / (time / 1000);
+      await delay(1000);
+      await fadeOut('download-progress');
+      saveFile(f);
+      state.storage.totalDownloads += 1;
+      metrics.completedDownload({ size, time, speed });
+      emitter.emit('pushState', '/completed');
+    } catch (err) {
+      // TODO cancelled download
+      const location = err.message === 'notfound' ? '/404' : '/error';
+      if (location === '/error') {
+        state.raven.captureException(err);
+        metrics.stoppedDownload({ size, err });
+      }
+      emitter.emit('replaceState', location);
+    } finally {
+      state.transfer = null;
+      openLinksInNewTab(links, false);
+    }
+  });
+
+  emitter.on('copy', ({ url, location }) => {
+    copyToClipboard(url);
+    metrics.copiedLink({ location });
+  });
+
+  setInterval(() => {
+    // poll for rerendering the file list countdown timers
+    if (
+      state.route === '/' &&
+      state.storage.files.length > 0 &&
+      Date.now() - lastRender > 30000
+    ) {
+      render();
+    }
+  }, 60000);
+}