[Workers] Add worker service

Add service for running WebWorkers, #12.

bundles.json

@@ -9,6 +9,7 @@
     "platform/commonUI/general",
     "platform/commonUI/inspect",
     "platform/containment",
+    "platform/execution",
     "platform/telemetry",
     "platform/features/layout",
     "platform/features/pages",

platform/execution/README.md

@@ -0,0 +1 @@
+Contains services which manage execution and flow control (e.g. for concurrency.)

platform/execution/bundle.json

@@ -0,0 +1,10 @@
+{
+    "extensions": {
+        "services": [
+            {
+                "key": "workerService",
+                "depends": [ "$window", "workers[]" ]
+            }
+        ]
+    }
+}

platform/execution/src/WorkerService.js

@@ -0,0 +1,68 @@
+/*****************************************************************************
+ * Open MCT Web, Copyright (c) 2014-2015, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT Web is licensed under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * Open MCT Web includes source code licensed under additional open source
+ * licenses. See the Open Source Licenses file (LICENSES.md) included with
+ * this source code distribution or the Licensing information page available
+ * at runtime from the About dialog for additional information.
+ *****************************************************************************/
+/*global define*/
+
+define(
+    [],
+    function () {
+        "use strict";
+
+        /**
+         * Handles the execution of WebWorkers.
+         * @constructor
+         */
+        function WorkerService($window, workers) {
+            var workerUrls = {},
+                Worker = $window.Worker;
+
+            function addWorker(worker) {
+                var key = worker.key;
+                if (!workerUrls[key]) {
+                    workerUrls[key] = [
+                        worker.bundle.path,
+                        worker.bundle.sources,
+                        worker.scriptUrl
+                    ].join("/");
+                }
+            }
+
+            (workers || []).forEach(addWorker);
+
+            return {
+                /**
+                 * Start running a new web worker. This will run a worker
+                 * that has been registered under the `workers` category
+                 * of extension.
+                 *
+                 * @param {string} key symbolic identifier for the worker
+                 * @returns {Worker} the running Worker
+                 */
+                run: function (key) {
+                    var scriptUrl = workerUrls[key];
+                    return scriptUrl && Worker && new Worker(scriptUrl);
+                }
+            };
+        }
+
+        return WorkerService;
+    }
+);

platform/execution/test/WorkerServiceSpec.js

@@ -0,0 +1,77 @@
+/*****************************************************************************
+ * Open MCT Web, Copyright (c) 2014-2015, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT Web is licensed under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * Open MCT Web includes source code licensed under additional open source
+ * licenses. See the Open Source Licenses file (LICENSES.md) included with
+ * this source code distribution or the Licensing information page available
+ * at runtime from the About dialog for additional information.
+ *****************************************************************************/
+/*global define,describe,it,expect,beforeEach,jasmine*/
+
+define(
+    ["../src/WorkerService"],
+    function (WorkerService) {
+        "use strict";
+
+        describe("The worker service", function () {
+            var mockWindow,
+                testWorkers,
+                mockWorker,
+                service;
+
+            beforeEach(function () {
+                mockWindow = jasmine.createSpyObj('$window', ['Worker']);
+                testWorkers = [
+                    {
+                        key: 'abc',
+                        scriptUrl: 'c.js',
+                        bundle: { path: 'a', sources: 'b' }
+                    },
+                    {
+                        key: 'xyz',
+                        scriptUrl: 'z.js',
+                        bundle: { path: 'x', sources: 'y' }
+                    },
+                    {
+                        key: 'xyz',
+                        scriptUrl: 'bad.js',
+                        bundle: { path: 'bad', sources: 'bad' }
+                    }
+                ];
+                mockWorker = {};
+
+                mockWindow.Worker.andReturn(mockWorker);
+
+                service = new WorkerService(mockWindow, testWorkers);
+            });
+
+            it("instantiates workers at registered paths", function () {
+                expect(service.run('abc')).toBe(mockWorker);
+                expect(mockWindow.Worker).toHaveBeenCalledWith('a/b/c.js');
+            });
+
+            it("prefers the first worker when multiple keys are found", function () {
+                expect(service.run('xyz')).toBe(mockWorker);
+                expect(mockWindow.Worker).toHaveBeenCalledWith('x/y/z.js');
+            });
+
+            it("returns undefined for unknown workers", function () {
+                expect(service.run('def')).toBeUndefined();
+            });
+
+        });
+    }
+);

platform/execution/test/suite.json

@@ -0,0 +1,3 @@
+[
+    "WorkerService"
+]