Move base64 conversions off of the main thread

libtextsecure/message_receiver.js

@@ -9,9 +9,112 @@
 /* global _: false */
 /* global ContactBuffer: false */
 /* global GroupBuffer: false */
+/* global Worker: false */
 
 /* eslint-disable more/no-then */
 
+const WORKER_TIMEOUT = 60 * 1000; // one minute
+
+const _utilWorker = new Worker('js/util_worker.js');
+const _jobs = Object.create(null);
+const _DEBUG = false;
+let _jobCounter = 0;
+
+function _makeJob(fnName) {
+  _jobCounter += 1;
+  const id = _jobCounter;
+
+  if (_DEBUG) {
+    window.log.info(`Worker job ${id} (${fnName}) started`);
+  }
+  _jobs[id] = {
+    fnName,
+    start: Date.now(),
+  };
+
+  return id;
+}
+
+function _updateJob(id, data) {
+  const { resolve, reject } = data;
+  const { fnName, start } = _jobs[id];
+
+  _jobs[id] = {
+    ..._jobs[id],
+    ...data,
+    resolve: value => {
+      _removeJob(id);
+      const end = Date.now();
+      window.log.info(
+        `Worker job ${id} (${fnName}) succeeded in ${end - start}ms`
+      );
+      return resolve(value);
+    },
+    reject: error => {
+      _removeJob(id);
+      const end = Date.now();
+      window.log.info(
+        `Worker job ${id} (${fnName}) failed in ${end - start}ms`
+      );
+      return reject(error);
+    },
+  };
+}
+
+function _removeJob(id) {
+  if (_DEBUG) {
+    _jobs[id].complete = true;
+  } else {
+    delete _jobs[id];
+  }
+}
+
+function _getJob(id) {
+  return _jobs[id];
+}
+
+async function callWorker(fnName, ...args) {
+  const jobId = _makeJob(fnName);
+
+  return new Promise((resolve, reject) => {
+    _utilWorker.postMessage([jobId, fnName, ...args]);
+
+    _updateJob(jobId, {
+      resolve,
+      reject,
+      args: _DEBUG ? args : null,
+    });
+
+    setTimeout(
+      () => reject(new Error(`Worker job ${jobId} (${fnName}) timed out`)),
+      WORKER_TIMEOUT
+    );
+  });
+}
+
+_utilWorker.onmessage = e => {
+  const [jobId, errorForDisplay, result] = e.data;
+
+  const job = _getJob(jobId);
+  if (!job) {
+    throw new Error(
+      `Received worker reply to job ${jobId}, but did not have it in our registry!`
+    );
+  }
+
+  const { resolve, reject, fnName } = job;
+
+  if (errorForDisplay) {
+    return reject(
+      new Error(
+        `Error received from worker job ${jobId} (${fnName}): ${errorForDisplay}`
+      )
+    );
+  }
+
+  return resolve(result);
+};
+
 function MessageReceiver(username, password, signalingKey, options = {}) {
   this.count = 0;
 
@@ -35,10 +138,11 @@ MessageReceiver.stringToArrayBuffer = string =>
   Promise.resolve(dcodeIO.ByteBuffer.wrap(string, 'binary').toArrayBuffer());
 MessageReceiver.arrayBufferToString = arrayBuffer =>
   Promise.resolve(dcodeIO.ByteBuffer.wrap(arrayBuffer).toString('binary'));
+
 MessageReceiver.stringToArrayBufferBase64 = string =>
-  Promise.resolve(dcodeIO.ByteBuffer.wrap(string, 'base64').toArrayBuffer());
+  callWorker('stringToArrayBufferBase64', string);
 MessageReceiver.arrayBufferToStringBase64 = arrayBuffer =>
-  Promise.resolve(dcodeIO.ByteBuffer.wrap(arrayBuffer).toString('base64'));
+  callWorker('arrayBufferToStringBase64', arrayBuffer);
 
 MessageReceiver.prototype = new textsecure.EventTarget();
 MessageReceiver.prototype.extend({