[Tables] Address performance issues observed in testathon (#2112)

* Use datum key of 'utc' for timestamp

* Do not try to get column values for data that does not have those values

* Collapse current time system columns

* Noop parsing for numbers in LocalTimeFormat

* Do not attempt to provide data for columns that object does not have telemetry for. Fixes #2027

platform/features/table/src/TableColumn.js

@@ -0,0 +1,69 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2018, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT 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 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.
+ *****************************************************************************/
+define(function () {
+    function TableColumn(openmct, telemetryObject, metadatum) {
+        this.openmct = openmct;
+        this.telemetryObject = telemetryObject;
+        this.metadatum = metadatum;
+        this.formatter = openmct.telemetry.getValueFormatter(metadatum);
+
+        this.titleValue = this.metadatum.name;
+    }
+
+    TableColumn.prototype.title = function (title) {
+        if (arguments.length > 0) {
+            this.titleValue = title;
+        }
+        return this.titleValue;
+    };
+
+    TableColumn.prototype.isCurrentTimeSystem = function () {
+        var isCurrentTimeSystem = this.metadatum.hints.hasOwnProperty('domain') &&
+        this.metadatum.key === this.openmct.time.timeSystem().key;
+
+        return isCurrentTimeSystem;
+    };
+
+    TableColumn.prototype.hasValue = function (telemetryObject, telemetryDatum) {
+        var keyStringForDatum = this.openmct.objects.makeKeyString(telemetryObject.identifier);
+        var keyStringForColumn = this.openmct.objects.makeKeyString(this.telemetryObject.identifier);
+        return keyStringForDatum === keyStringForColumn && telemetryDatum.hasOwnProperty(this.metadatum.source);
+    };
+
+    TableColumn.prototype.getValue = function (telemetryDatum, limitEvaluator) {
+        var isValueColumn = !!(this.metadatum.hints.y || this.metadatum.hints.range);
+        var alarm = isValueColumn &&
+                    limitEvaluator &&
+                    limitEvaluator.evaluate(telemetryDatum, this.metadatum);
+        var value = {
+            text: this.formatter.format(telemetryDatum),
+            value: this.formatter.parse(telemetryDatum)
+        };
+
+        if (alarm) {
+            value.cssClass = alarm.cssClass;
+        }
+        return value;
+    };
+
+    return TableColumn;
+});