1 files changed, 183 insertions, 0 deletions
diff --git a/toolkit/components/telemetry/other/UITelemetry.jsm b/toolkit/components/telemetry/other/UITelemetry.jsm
new file mode 100644
index 0000000000..b14b55bb2f
--- /dev/null
+++ b/toolkit/components/telemetry/other/UITelemetry.jsm
@@ -0,0 +1,183 @@
+/* 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";
+
+var EXPORTED_SYMBOLS = ["UITelemetry"];
+
+ChromeUtils.import("resource://gre/modules/Services.jsm", this);
+ChromeUtils.import("resource://gre/modules/TelemetryUtils.jsm", this);
+
+/**
+ * UITelemetry is a helper JSM used to record UI specific telemetry events.
+ *
+ * It implements nsIUITelemetryObserver, defined in nsIAndroidBridge.idl.
+ */
+var UITelemetry = {
+  _enabled: undefined,
+  _activeSessions: {},
+  _measurements: [],
+
+  // Lazily decide whether telemetry is enabled.
+  get enabled() {
+    if (this._enabled !== undefined) {
+      return this._enabled;
+    }
+
+    // Set an observer to watch for changes at runtime.
+    Services.prefs.addObserver(
+      TelemetryUtils.Preferences.TelemetryEnabled,
+      this
+    );
+    Services.obs.addObserver(this, "profile-before-change");
+
+    // Pick up the current value.
+    this._enabled = Services.prefs.getBoolPref(
+      TelemetryUtils.Preferences.TelemetryEnabled,
+      false
+    );
+
+    return this._enabled;
+  },
+
+  observe(aSubject, aTopic, aData) {
+    if (aTopic == "profile-before-change") {
+      Services.obs.removeObserver(this, "profile-before-change");
+      Services.prefs.removeObserver(
+        TelemetryUtils.Preferences.TelemetryEnabled,
+        this
+      );
+      this._enabled = undefined;
+      return;
+    }
+
+    if (aTopic == "nsPref:changed") {
+      switch (aData) {
+        case TelemetryUtils.Preferences.TelemetryEnabled:
+          let on = Services.prefs.getBoolPref(
+            TelemetryUtils.Preferences.TelemetryEnabled
+          );
+          this._enabled = on;
+
+          // Wipe ourselves if we were just disabled.
+          if (!on) {
+            this._activeSessions = {};
+            this._measurements = [];
+          }
+          break;
+      }
+    }
+  },
+
+  /**
+   * This exists exclusively for testing -- our events are not intended to
+   * be retrieved via an XPCOM interface.
+   */
+  get wrappedJSObject() {
+    return this;
+  },
+
+  /**
+   * A hack to generate the relative timestamp from start when we don't have
+   * access to the Java timer.
+   * XXX: Bug 1007647 - Support realtime and/or uptime in JavaScript.
+   */
+  uptimeMillis() {
+    return Date.now() - Services.startup.getStartupInfo().process;
+  },
+
+  /**
+   * Adds a single event described by a timestamp, an action, and the calling
+   * method.
+   *
+   * Optionally provide a string 'extras', which will be recorded as part of
+   * the event.
+   *
+   * All extant sessions will be recorded by name for each event.
+   */
+  addEvent(aAction, aMethod, aTimestamp, aExtras) {
+    if (!this.enabled) {
+      return;
+    }
+
+    let sessions = Object.keys(this._activeSessions);
+    let aEvent = {
+      type: "event",
+      action: aAction,
+      method: aMethod,
+      sessions,
+      timestamp: aTimestamp == undefined ? this.uptimeMillis() : aTimestamp,
+    };
+
+    if (aExtras) {
+      aEvent.extras = aExtras;
+    }
+
+    this._recordEvent(aEvent);
+  },
+
+  /**
+   * Begins tracking a session by storing a timestamp for session start.
+   */
+  startSession(aName, aTimestamp) {
+    if (!this.enabled) {
+      return;
+    }
+
+    if (this._activeSessions[aName]) {
+      // Do not overwrite a previous event start if it already exists.
+      return;
+    }
+    this._activeSessions[aName] =
+      aTimestamp == undefined ? this.uptimeMillis() : aTimestamp;
+  },
+
+  /**
+   * Tracks the end of a session with a timestamp.
+   */
+  stopSession(aName, aReason, aTimestamp) {
+    if (!this.enabled) {
+      return;
+    }
+
+    let sessionStart = this._activeSessions[aName];
+    delete this._activeSessions[aName];
+
+    if (!sessionStart) {
+      return;
+    }
+
+    let aEvent = {
+      type: "session",
+      name: aName,
+      reason: aReason,
+      start: sessionStart,
+      end: aTimestamp == undefined ? this.uptimeMillis() : aTimestamp,
+    };
+
+    this._recordEvent(aEvent);
+  },
+
+  _recordEvent(aEvent) {
+    this._measurements.push(aEvent);
+  },
+
+  /**
+   * Called by TelemetrySession to populate the UI measurement
+   * blob.
+   *
+   * Optionally clears the set of measurements based on aClear.
+   */
+  getUIMeasurements(aClear) {
+    if (!this.enabled) {
+      return [];
+    }
+
+    let measurements = this._measurements.slice();
+    if (aClear) {
+      this._measurements = [];
+    }
+    return measurements;
+  },
+};