1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/services/datareporting/sessions.jsm Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,406 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +"use strict";
1.9 +
1.10 +#ifndef MERGED_COMPARTMENT
1.11 +
1.12 +this.EXPORTED_SYMBOLS = [
1.13 + "SessionRecorder",
1.14 +];
1.15 +
1.16 +const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
1.17 +
1.18 +#endif
1.19 +
1.20 +Cu.import("resource://gre/modules/Preferences.jsm");
1.21 +Cu.import("resource://gre/modules/XPCOMUtils.jsm");
1.22 +Cu.import("resource://gre/modules/Log.jsm");
1.23 +Cu.import("resource://services-common/utils.js");
1.24 +
1.25 +
1.26 +// We automatically prune sessions older than this.
1.27 +const MAX_SESSION_AGE_MS = 7 * 24 * 60 * 60 * 1000; // 7 days.
1.28 +const STARTUP_RETRY_INTERVAL_MS = 5000;
1.29 +
1.30 +// Wait up to 5 minutes for startup measurements before giving up.
1.31 +const MAX_STARTUP_TRIES = 300000 / STARTUP_RETRY_INTERVAL_MS;
1.32 +
1.33 +/**
1.34 + * Records information about browser sessions.
1.35 + *
1.36 + * This serves as an interface to both current session information as
1.37 + * well as a history of previous sessions.
1.38 + *
1.39 + * Typically only one instance of this will be installed in an
1.40 + * application. It is typically managed by an XPCOM service. The
1.41 + * instance is instantiated at application start; onStartup is called
1.42 + * once the profile is installed; onShutdown is called during shutdown.
1.43 + *
1.44 + * We currently record state in preferences. However, this should be
1.45 + * invisible to external consumers. We could easily swap in a different
1.46 + * storage mechanism if desired.
1.47 + *
1.48 + * Please note the different semantics for storing times and dates in
1.49 + * preferences. Full dates (notably the session start time) are stored
1.50 + * as strings because preferences have a 32-bit limit on integer values
1.51 + * and milliseconds since UNIX epoch would overflow. Many times are
1.52 + * stored as integer offsets from the session start time because they
1.53 + * should not overflow 32 bits.
1.54 + *
1.55 + * Since this records history of all sessions, there is a possibility
1.56 + * for unbounded data aggregation. This is curtailed through:
1.57 + *
1.58 + * 1) An "idle-daily" observer which delete sessions older than
1.59 + * MAX_SESSION_AGE_MS.
1.60 + * 2) The creator of this instance explicitly calling
1.61 + * `pruneOldSessions`.
1.62 + *
1.63 + * @param branch
1.64 + * (string) Preferences branch on which to record state.
1.65 + */
1.66 +this.SessionRecorder = function (branch) {
1.67 + if (!branch) {
1.68 + throw new Error("branch argument must be defined.");
1.69 + }
1.70 +
1.71 + if (!branch.endsWith(".")) {
1.72 + throw new Error("branch argument must end with '.': " + branch);
1.73 + }
1.74 +
1.75 + this._log = Log.repository.getLogger("Services.DataReporting.SessionRecorder");
1.76 +
1.77 + this._prefs = new Preferences(branch);
1.78 + this._lastActivityWasInactive = false;
1.79 + this._activeTicks = 0;
1.80 + this.fineTotalTime = 0;
1.81 + this._started = false;
1.82 + this._timer = null;
1.83 + this._startupFieldTries = 0;
1.84 +
1.85 + this._os = Cc["@mozilla.org/observer-service;1"]
1.86 + .getService(Ci.nsIObserverService);
1.87 +
1.88 +};
1.89 +
1.90 +SessionRecorder.prototype = Object.freeze({
1.91 + QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver]),
1.92 +
1.93 + STARTUP_RETRY_INTERVAL_MS: STARTUP_RETRY_INTERVAL_MS,
1.94 +
1.95 + get _currentIndex() {
1.96 + return this._prefs.get("currentIndex", 0);
1.97 + },
1.98 +
1.99 + set _currentIndex(value) {
1.100 + this._prefs.set("currentIndex", value);
1.101 + },
1.102 +
1.103 + get _prunedIndex() {
1.104 + return this._prefs.get("prunedIndex", 0);
1.105 + },
1.106 +
1.107 + set _prunedIndex(value) {
1.108 + this._prefs.set("prunedIndex", value);
1.109 + },
1.110 +
1.111 + get startDate() {
1.112 + return CommonUtils.getDatePref(this._prefs, "current.startTime");
1.113 + },
1.114 +
1.115 + set _startDate(value) {
1.116 + CommonUtils.setDatePref(this._prefs, "current.startTime", value);
1.117 + },
1.118 +
1.119 + get activeTicks() {
1.120 + return this._prefs.get("current.activeTicks", 0);
1.121 + },
1.122 +
1.123 + incrementActiveTicks: function () {
1.124 + this._prefs.set("current.activeTicks", ++this._activeTicks);
1.125 + },
1.126 +
1.127 + /**
1.128 + * Total time of this session in integer seconds.
1.129 + *
1.130 + * See also fineTotalTime for the time in milliseconds.
1.131 + */
1.132 + get totalTime() {
1.133 + return this._prefs.get("current.totalTime", 0);
1.134 + },
1.135 +
1.136 + updateTotalTime: function () {
1.137 + // We store millisecond precision internally to prevent drift from
1.138 + // repeated rounding.
1.139 + this.fineTotalTime = Date.now() - this.startDate;
1.140 + this._prefs.set("current.totalTime", Math.floor(this.fineTotalTime / 1000));
1.141 + },
1.142 +
1.143 + get main() {
1.144 + return this._prefs.get("current.main", -1);
1.145 + },
1.146 +
1.147 + set _main(value) {
1.148 + if (!Number.isInteger(value)) {
1.149 + throw new Error("main time must be an integer.");
1.150 + }
1.151 +
1.152 + this._prefs.set("current.main", value);
1.153 + },
1.154 +
1.155 + get firstPaint() {
1.156 + return this._prefs.get("current.firstPaint", -1);
1.157 + },
1.158 +
1.159 + set _firstPaint(value) {
1.160 + if (!Number.isInteger(value)) {
1.161 + throw new Error("firstPaint must be an integer.");
1.162 + }
1.163 +
1.164 + this._prefs.set("current.firstPaint", value);
1.165 + },
1.166 +
1.167 + get sessionRestored() {
1.168 + return this._prefs.get("current.sessionRestored", -1);
1.169 + },
1.170 +
1.171 + set _sessionRestored(value) {
1.172 + if (!Number.isInteger(value)) {
1.173 + throw new Error("sessionRestored must be an integer.");
1.174 + }
1.175 +
1.176 + this._prefs.set("current.sessionRestored", value);
1.177 + },
1.178 +
1.179 + getPreviousSessions: function () {
1.180 + let result = {};
1.181 +
1.182 + for (let i = this._prunedIndex; i < this._currentIndex; i++) {
1.183 + let s = this.getPreviousSession(i);
1.184 + if (!s) {
1.185 + continue;
1.186 + }
1.187 +
1.188 + result[i] = s;
1.189 + }
1.190 +
1.191 + return result;
1.192 + },
1.193 +
1.194 + getPreviousSession: function (index) {
1.195 + return this._deserialize(this._prefs.get("previous." + index));
1.196 + },
1.197 +
1.198 + /**
1.199 + * Prunes old, completed sessions that started earlier than the
1.200 + * specified date.
1.201 + */
1.202 + pruneOldSessions: function (date) {
1.203 + for (let i = this._prunedIndex; i < this._currentIndex; i++) {
1.204 + let s = this.getPreviousSession(i);
1.205 + if (!s) {
1.206 + continue;
1.207 + }
1.208 +
1.209 + if (s.startDate >= date) {
1.210 + continue;
1.211 + }
1.212 +
1.213 + this._log.debug("Pruning session #" + i + ".");
1.214 + this._prefs.reset("previous." + i);
1.215 + this._prunedIndex = i;
1.216 + }
1.217 + },
1.218 +
1.219 + recordStartupFields: function () {
1.220 + let si = this._getStartupInfo();
1.221 +
1.222 + if (!si.process) {
1.223 + throw new Error("Startup info not available.");
1.224 + }
1.225 +
1.226 + let missing = false;
1.227 +
1.228 + for (let field of ["main", "firstPaint", "sessionRestored"]) {
1.229 + if (!(field in si)) {
1.230 + this._log.debug("Missing startup field: " + field);
1.231 + missing = true;
1.232 + continue;
1.233 + }
1.234 +
1.235 + this["_" + field] = si[field].getTime() - si.process.getTime();
1.236 + }
1.237 +
1.238 + if (!missing || this._startupFieldTries > MAX_STARTUP_TRIES) {
1.239 + this._clearStartupTimer();
1.240 + return;
1.241 + }
1.242 +
1.243 + // If we have missing fields, install a timer and keep waiting for
1.244 + // data.
1.245 + this._startupFieldTries++;
1.246 +
1.247 + if (!this._timer) {
1.248 + this._timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
1.249 + this._timer.initWithCallback({
1.250 + notify: this.recordStartupFields.bind(this),
1.251 + }, this.STARTUP_RETRY_INTERVAL_MS, this._timer.TYPE_REPEATING_SLACK);
1.252 + }
1.253 + },
1.254 +
1.255 + _clearStartupTimer: function () {
1.256 + if (this._timer) {
1.257 + this._timer.cancel();
1.258 + delete this._timer;
1.259 + }
1.260 + },
1.261 +
1.262 + /**
1.263 + * Perform functionality on application startup.
1.264 + *
1.265 + * This is typically called in a "profile-do-change" handler.
1.266 + */
1.267 + onStartup: function () {
1.268 + if (this._started) {
1.269 + throw new Error("onStartup has already been called.");
1.270 + }
1.271 +
1.272 + let si = this._getStartupInfo();
1.273 + if (!si.process) {
1.274 + throw new Error("Process information not available. Misconfigured app?");
1.275 + }
1.276 +
1.277 + this._started = true;
1.278 +
1.279 + this._os.addObserver(this, "profile-before-change", false);
1.280 + this._os.addObserver(this, "user-interaction-active", false);
1.281 + this._os.addObserver(this, "user-interaction-inactive", false);
1.282 + this._os.addObserver(this, "idle-daily", false);
1.283 +
1.284 + // This has the side-effect of clearing current session state.
1.285 + this._moveCurrentToPrevious();
1.286 +
1.287 + this._startDate = si.process;
1.288 + this._prefs.set("current.activeTicks", 0);
1.289 + this.updateTotalTime();
1.290 +
1.291 + this.recordStartupFields();
1.292 + },
1.293 +
1.294 + /**
1.295 + * Record application activity.
1.296 + */
1.297 + onActivity: function (active) {
1.298 + let updateActive = active && !this._lastActivityWasInactive;
1.299 + this._lastActivityWasInactive = !active;
1.300 +
1.301 + this.updateTotalTime();
1.302 +
1.303 + if (updateActive) {
1.304 + this.incrementActiveTicks();
1.305 + }
1.306 + },
1.307 +
1.308 + onShutdown: function () {
1.309 + this._log.info("Recording clean session shutdown.");
1.310 + this._prefs.set("current.clean", true);
1.311 + this.updateTotalTime();
1.312 + this._clearStartupTimer();
1.313 +
1.314 + this._os.removeObserver(this, "profile-before-change");
1.315 + this._os.removeObserver(this, "user-interaction-active");
1.316 + this._os.removeObserver(this, "user-interaction-inactive");
1.317 + this._os.removeObserver(this, "idle-daily");
1.318 + },
1.319 +
1.320 + _CURRENT_PREFS: [
1.321 + "current.startTime",
1.322 + "current.activeTicks",
1.323 + "current.totalTime",
1.324 + "current.main",
1.325 + "current.firstPaint",
1.326 + "current.sessionRestored",
1.327 + "current.clean",
1.328 + ],
1.329 +
1.330 + // This is meant to be called only during onStartup().
1.331 + _moveCurrentToPrevious: function () {
1.332 + try {
1.333 + if (!this.startDate.getTime()) {
1.334 + this._log.info("No previous session. Is this first app run?");
1.335 + return;
1.336 + }
1.337 +
1.338 + let clean = this._prefs.get("current.clean", false);
1.339 +
1.340 + let count = this._currentIndex++;
1.341 + let obj = {
1.342 + s: this.startDate.getTime(),
1.343 + a: this.activeTicks,
1.344 + t: this.totalTime,
1.345 + c: clean,
1.346 + m: this.main,
1.347 + fp: this.firstPaint,
1.348 + sr: this.sessionRestored,
1.349 + };
1.350 +
1.351 + this._log.debug("Recording last sessions as #" + count + ".");
1.352 + this._prefs.set("previous." + count, JSON.stringify(obj));
1.353 + } catch (ex) {
1.354 + this._log.warn("Exception when migrating last session: " +
1.355 + CommonUtils.exceptionStr(ex));
1.356 + } finally {
1.357 + this._log.debug("Resetting prefs from last session.");
1.358 + for (let pref of this._CURRENT_PREFS) {
1.359 + this._prefs.reset(pref);
1.360 + }
1.361 + }
1.362 + },
1.363 +
1.364 + _deserialize: function (s) {
1.365 + let o;
1.366 + try {
1.367 + o = JSON.parse(s);
1.368 + } catch (ex) {
1.369 + return null;
1.370 + }
1.371 +
1.372 + return {
1.373 + startDate: new Date(o.s),
1.374 + activeTicks: o.a,
1.375 + totalTime: o.t,
1.376 + clean: !!o.c,
1.377 + main: o.m,
1.378 + firstPaint: o.fp,
1.379 + sessionRestored: o.sr,
1.380 + };
1.381 + },
1.382 +
1.383 + // Implemented as a function to allow for monkeypatching in tests.
1.384 + _getStartupInfo: function () {
1.385 + return Cc["@mozilla.org/toolkit/app-startup;1"]
1.386 + .getService(Ci.nsIAppStartup)
1.387 + .getStartupInfo();
1.388 + },
1.389 +
1.390 + observe: function (subject, topic, data) {
1.391 + switch (topic) {
1.392 + case "profile-before-change":
1.393 + this.onShutdown();
1.394 + break;
1.395 +
1.396 + case "user-interaction-active":
1.397 + this.onActivity(true);
1.398 + break;
1.399 +
1.400 + case "user-interaction-inactive":
1.401 + this.onActivity(false);
1.402 + break;
1.403 +
1.404 + case "idle-daily":
1.405 + this.pruneOldSessions(new Date(Date.now() - MAX_SESSION_AGE_MS));
1.406 + break;
1.407 + }
1.408 + },
1.409 +});
