[Telemetry] Add data structure specs

Add specs for data structures which will support resolution
of WTD-784 by retaining all data not yet received by callbacks
(instead of just the very latest) such that plots can ensure
they do not miss streaming data.

platform/telemetry/src/TelemetrySubscription.js

@@ -1,8 +1,8 @@
 /*global define*/
 
 define(
-    [],
-    function () {
+    ['./TelemetryQueue', './TelemetryTable'],
+    function (TelemetryQueue, TelemetryTable) {
         "use strict";
 
 
@@ -25,11 +25,16 @@ define(
          *        associated telemetry data is of interest
          * @param {Function} callback a function to invoke
          *        when new data has become available.
+         * @param {boolean} lossless true if callback should be invoked
+         *        once with every data point available; otherwise, multiple
+         *        data events in a short period of time will only invoke
+         *        the callback once, with access to the latest data
          */
-        function TelemetrySubscription($q, $timeout, domainObject, callback) {
+        function TelemetrySubscription($q, $timeout, domainObject, callback, lossless) {
             var unsubscribePromise,
                 latestValues = {},
                 telemetryObjects = [],
+                pool = lossless ? new TelemetryQueue() : new TelemetryTable(),
                 metadatas,
                 updatePending;
 
@@ -56,10 +61,22 @@ define(
                 });
             }
 
+            function updateValuesFromPool() {
+                var values = pool.poll();
+                Object.keys(values).forEach(function (k) {
+                    latestValues[k] = values[k];
+                });
+            }
+
             // Invoke the observer callback to notify that new streaming
             // data has become available.
             function fireCallback() {
-                callback();
+                // Play back from queue if we are lossless
+                while (!pool.isEmpty()) {
+                    updateValuesFromPool();
+                    callback();
+                }
+
                 // Clear the pending flag so that future updates will
                 // schedule this callback.
                 updatePending = false;
@@ -80,10 +97,10 @@ define(
 
                 // Update the latest-value table
                 if (count > 0) {
-                    latestValues[domainObject.getId()] = {
+                    pool.put(domainObject.getId(), {
                         domain: telemetry.getDomainValue(count - 1),
                         range: telemetry.getRangeValue(count - 1)
-                    };
+                    });
                 }
             }
 

platform/telemetry/test/TelemetryQueueSpec.js

@@ -0,0 +1,55 @@
+/*global define,Promise,describe,it,expect,beforeEach,waitsFor,jasmine*/
+
+define(
+    ["../src/TelemetryQueue"],
+    function (TelemetryQueue) {
+        "use strict";
+
+        describe("The telemetry queue", function () {
+            var queue;
+
+            beforeEach(function () {
+                // put, isEmpty, dequeue
+                queue = new TelemetryQueue();
+            });
+
+            it("stores elements by key", function () {
+                queue.put("a", { someKey: "some value" });
+                expect(queue.poll())
+                    .toEqual({ a: { someKey: "some value" }});
+            });
+
+            it("merges non-overlapping keys", function () {
+                queue.put("a", { someKey: "some value" });
+                queue.put("b", 42);
+                expect(queue.poll())
+                    .toEqual({ a: { someKey: "some value" }, b: 42 });
+            });
+
+            it("adds new objects for repeated keys", function () {
+                queue.put("a", { someKey: "some value" });
+                queue.put("a", { someKey: "some other value" });
+                queue.put("b", 42);
+                expect(queue.poll())
+                    .toEqual({ a: { someKey: "some value" }, b: 42 });
+                expect(queue.poll())
+                    .toEqual({ a: { someKey: "some other value" }  });
+            });
+
+            it("reports emptiness", function () {
+                expect(queue.isEmpty()).toBeTruthy();
+                queue.put("a", { someKey: "some value" });
+                queue.put("a", { someKey: "some other value" });
+                queue.put("b", 42);
+                expect(queue.isEmpty()).toBeFalsy();
+                queue.poll();
+                expect(queue.isEmpty()).toBeFalsy();
+                queue.poll();
+                expect(queue.isEmpty()).toBeTruthy();
+            });
+
+
+        });
+
+    }
+);

platform/telemetry/test/TelemetryTableSpec.js

@@ -0,0 +1,53 @@
+/*global define,Promise,describe,it,expect,beforeEach,waitsFor,jasmine*/
+
+define(
+    ["../src/TelemetryTable"],
+    function (TelemetryTable) {
+        "use strict";
+
+        describe("The telemetry table", function () {
+            var queue;
+
+            beforeEach(function () {
+                // put, isEmpty, dequeue
+                queue = new TelemetryTable();
+            });
+
+            it("stores elements by key", function () {
+                queue.put("a", { someKey: "some value" });
+                expect(queue.poll())
+                    .toEqual({ a: { someKey: "some value" }});
+            });
+
+            it("merges non-overlapping keys", function () {
+                queue.put("a", { someKey: "some value" });
+                queue.put("b", 42);
+                expect(queue.poll())
+                    .toEqual({ a: { someKey: "some value" }, b: 42 });
+            });
+
+            it("overwrites repeated keys", function () {
+                queue.put("a", { someKey: "some value" });
+                queue.put("a", { someKey: "some other value" });
+                queue.put("b", 42);
+                expect(queue.poll())
+                    .toEqual({ a: { someKey: "some other value" }, b: 42 });
+                expect(queue.poll())
+                    .toBeUndefined();
+            });
+
+            it("reports emptiness", function () {
+                expect(queue.isEmpty()).toBeTruthy();
+                queue.put("a", { someKey: "some value" });
+                queue.put("a", { someKey: "some other value" });
+                queue.put("b", 42);
+                expect(queue.isEmpty()).toBeFalsy();
+                queue.poll();
+                expect(queue.isEmpty()).toBeTruthy();
+            });
+
+
+        });
+
+    }
+);

platform/telemetry/test/suite.json

@@ -3,6 +3,8 @@
     "TelemetryCapability",
     "TelemetryController",
     "TelemetryFormatter",
+    "TelemetryQueue",
     "TelemetrySubscriber",
-    "TelemetrySubscription"
+    "TelemetrySubscription",
+    "TelemetryTable"
 ]