michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /**
michael@0:  * Collects telemetry data for Tabview.
michael@0:  */
michael@0: let Telemetry = {
michael@0:   TOPIC_GATHER_TELEMETRY: "gather-telemetry",
michael@0: 
michael@0:   /**
michael@0:    * Initializes the object.
michael@0:    */
michael@0:   init: function Telemetry_init() {
michael@0:     Services.obs.addObserver(this, this.TOPIC_GATHER_TELEMETRY, false);
michael@0:   }, 
michael@0: 
michael@0:   /**
michael@0:    * Uninitializes the object.
michael@0:    */
michael@0:   uninit: function Telemetry_uninit() {
michael@0:     Services.obs.removeObserver(this, this.TOPIC_GATHER_TELEMETRY);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Adds telemetry values to gather usage statistics.
michael@0:    */
michael@0:   _collect: function Telemetry_collect() {
michael@0:     let stackedGroupsCount = 0;
michael@0:     let childCounts = [];
michael@0: 
michael@0:     GroupItems.groupItems.forEach(function (groupItem) {
michael@0:       if (!groupItem.isEmpty()) {
michael@0:         childCounts.push(groupItem.getChildren().length);
michael@0: 
michael@0:         if (groupItem.isStacked())
michael@0:           stackedGroupsCount++;
michael@0:       }
michael@0:     });
michael@0: 
michael@0:     function addTelemetryValue(aId, aValue) {
michael@0:       Services.telemetry.getHistogramById("PANORAMA_" + aId).add(aValue);
michael@0:     }
michael@0:     function median(aChildCounts) {
michael@0:       aChildCounts.sort(function(x, y) { return x - y; });
michael@0:       let middle = Math.floor(aChildCounts.length / 2);
michael@0:       return aChildCounts[middle];
michael@0:     }
michael@0: 
michael@0:     addTelemetryValue("GROUPS_COUNT", GroupItems.groupItems.length);
michael@0:     addTelemetryValue("STACKED_GROUPS_COUNT", stackedGroupsCount);
michael@0:     addTelemetryValue("MEDIAN_TABS_IN_GROUPS_COUNT", median(childCounts));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Observes for gather telemetry topic.
michael@0:    */
michael@0:   observe: function Telemetry_observe(aSubject, aTopic, aData) {
michael@0:     if (!gWindow.PrivateBrowsingUtils.isWindowPrivate(gWindow))
michael@0:       this._collect();
michael@0:   }
michael@0: }
michael@0: