1 files changed, 56 insertions, 0 deletions
diff --git a/toolkit/jetpack/sdk/addon/events.js b/toolkit/jetpack/sdk/addon/events.js
new file mode 100644
index 000000000..45bada6e1
--- /dev/null
+++ b/toolkit/jetpack/sdk/addon/events.js
@@ -0,0 +1,56 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+'use strict';
+
+module.metadata = {
+  'stability': 'experimental'
+};
+
+var { request: hostReq, response: hostRes } = require('./host');
+var { defer: async } = require('../lang/functional');
+var { defer } = require('../core/promise');
+var { emit: emitSync, on, off } = require('../event/core');
+var { uuid } = require('../util/uuid');
+var emit = async(emitSync);
+
+// Map of IDs to deferreds
+var requests = new Map();
+
+// May not be necessary to wrap this in `async`
+// once promises are async via bug 881047
+var receive = async(function ({data, id, error}) {
+  let request = requests.get(id);
+  if (request) {
+    if (error) request.reject(error);
+    else request.resolve(clone(data));
+    requests.delete(id);
+  }
+});
+on(hostRes, 'data', receive);
+
+/*
+ * Send is a helper to be used in client APIs to send
+ * a request to host
+ */
+function send (eventName, data) {
+  let id = uuid();
+  let deferred = defer();
+  requests.set(id, deferred);
+  emit(hostReq, 'data', {
+    id: id,
+    data: clone(data),
+    event: eventName
+  });
+  return deferred.promise;
+}
+exports.send = send;
+
+/*
+ * Implement internal structured cloning algorithm in the future?
+ * http://www.whatwg.org/specs/web-apps/current-work/multipage/common-dom-interfaces.html#internal-structured-cloning-algorithm
+ */
+function clone (obj) {
+  return JSON.parse(JSON.stringify(obj || {}));
+}