1 files changed, 152 insertions, 0 deletions
diff --git a/toolkit/components/telemetry/TelemetryUtils.jsm b/toolkit/components/telemetry/TelemetryUtils.jsm
new file mode 100644
index 000000000..4d934c9c1
--- /dev/null
+++ b/toolkit/components/telemetry/TelemetryUtils.jsm
@@ -0,0 +1,152 @@
+/* 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";
+
+this.EXPORTED_SYMBOLS = [
+  "TelemetryUtils"
+];
+
+const {classes: Cc, interfaces: Ci, results: Cr, utils: Cu} = Components;
+
+Cu.import("resource://gre/modules/Preferences.jsm", this);
+
+const MILLISECONDS_PER_DAY = 24 * 60 * 60 * 1000;
+
+const PREF_TELEMETRY_ENABLED = "toolkit.telemetry.enabled";
+
+const IS_CONTENT_PROCESS = (function() {
+  // We cannot use Services.appinfo here because in telemetry xpcshell tests,
+  // appinfo is initially unavailable, and becomes available only later on.
+  let runtime = Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULRuntime);
+  return runtime.processType == Ci.nsIXULRuntime.PROCESS_TYPE_CONTENT;
+})();
+
+this.TelemetryUtils = {
+  /**
+   * True if this is a content process.
+   */
+  get isContentProcess() {
+    return IS_CONTENT_PROCESS;
+  },
+
+  /**
+   * Returns the state of the Telemetry enabled preference, making sure
+   * it correctly evaluates to a boolean type.
+   */
+  get isTelemetryEnabled() {
+    return Preferences.get(PREF_TELEMETRY_ENABLED, false) === true;
+  },
+
+  /**
+   * Turn a millisecond timestamp into a day timestamp.
+   *
+   * @param aMsec A number of milliseconds since Unix epoch.
+   * @return The number of whole days since Unix epoch.
+   */
+  millisecondsToDays: function(aMsec) {
+    return Math.floor(aMsec / MILLISECONDS_PER_DAY);
+  },
+
+  /**
+   * Takes a date and returns it trunctated to a date with daily precision.
+   */
+  truncateToDays: function(date) {
+    return new Date(date.getFullYear(),
+                    date.getMonth(),
+                    date.getDate(),
+                    0, 0, 0, 0);
+  },
+
+  /**
+   * Check if the difference between the times is within the provided tolerance.
+   * @param {Number} t1 A time in milliseconds.
+   * @param {Number} t2 A time in milliseconds.
+   * @param {Number} tolerance The tolerance, in milliseconds.
+   * @return {Boolean} True if the absolute time difference is within the tolerance, false
+   *                   otherwise.
+   */
+  areTimesClose: function(t1, t2, tolerance) {
+    return Math.abs(t1 - t2) <= tolerance;
+  },
+
+  /**
+   * Get the next midnight for a date.
+   * @param {Object} date The date object to check.
+   * @return {Object} The Date object representing the next midnight.
+   */
+  getNextMidnight: function(date) {
+    let nextMidnight = new Date(this.truncateToDays(date));
+    nextMidnight.setDate(nextMidnight.getDate() + 1);
+    return nextMidnight;
+  },
+
+  /**
+   * Get the midnight which is closer to the provided date.
+   * @param {Object} date The date object to check.
+   * @param {Number} tolerance The tolerance within we find the closest midnight.
+   * @return {Object} The Date object representing the closes midnight, or null if midnight
+   *                  is not within the midnight tolerance.
+   */
+  getNearestMidnight: function(date, tolerance) {
+    let lastMidnight = this.truncateToDays(date);
+    if (this.areTimesClose(date.getTime(), lastMidnight.getTime(), tolerance)) {
+      return lastMidnight;
+    }
+
+    const nextMidnightDate = this.getNextMidnight(date);
+    if (this.areTimesClose(date.getTime(), nextMidnightDate.getTime(), tolerance)) {
+      return nextMidnightDate;
+    }
+    return null;
+  },
+
+  generateUUID: function() {
+    let str = Cc["@mozilla.org/uuid-generator;1"].getService(Ci.nsIUUIDGenerator).generateUUID().toString();
+    // strip {}
+    return str.substring(1, str.length - 1);
+  },
+
+  /**
+   * Find how many months passed between two dates.
+   * @param {Object} aStartDate The starting date.
+   * @param {Object} aEndDate The ending date.
+   * @return {Integer} The number of months between the two dates.
+   */
+  getElapsedTimeInMonths: function(aStartDate, aEndDate) {
+    return (aEndDate.getMonth() - aStartDate.getMonth())
+           + 12 * (aEndDate.getFullYear() - aStartDate.getFullYear());
+  },
+
+  /**
+   * Date.toISOString() gives us UTC times, this gives us local times in
+   * the ISO date format. See http://www.w3.org/TR/NOTE-datetime
+   * @param {Object} date The input date.
+   * @return {String} The local time ISO string.
+   */
+  toLocalTimeISOString: function(date) {
+    function padNumber(number, places) {
+      number = number.toString();
+      while (number.length < places) {
+        number = "0" + number;
+      }
+      return number;
+    }
+
+    let sign = (n) => n >= 0 ? "+" : "-";
+    // getTimezoneOffset counter-intuitively returns -60 for UTC+1.
+    let tzOffset = - date.getTimezoneOffset();
+
+    // YYYY-MM-DDThh:mm:ss.sTZD (eg 1997-07-16T19:20:30.45+01:00)
+    return    padNumber(date.getFullYear(), 4)
+      + "-" + padNumber(date.getMonth() + 1, 2)
+      + "-" + padNumber(date.getDate(), 2)
+      + "T" + padNumber(date.getHours(), 2)
+      + ":" + padNumber(date.getMinutes(), 2)
+      + ":" + padNumber(date.getSeconds(), 2)
+      + "." + date.getMilliseconds()
+      + sign(tzOffset) + padNumber(Math.floor(Math.abs(tzOffset / 60)), 2)
+      + ":" + padNumber(Math.abs(tzOffset % 60), 2);
+  },
+};