summaryrefslogtreecommitdiffstats
path: root/browser/modules/SelfSupportBackend.jsm
blob: 27072732ed8d2337f3687c1a06d3169ea2abfbc8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
/* 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 = ["SelfSupportBackend"];

const Cu = Components.utils;
const Cc = Components.classes;
const Ci = Components.interfaces;

Cu.import("resource://gre/modules/Log.jsm");
Cu.import("resource://gre/modules/Preferences.jsm");
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/Timer.jsm");
Cu.import("resource://gre/modules/XPCOMUtils.jsm");

XPCOMUtils.defineLazyModuleGetter(this, "HiddenFrame",
  "resource:///modules/HiddenFrame.jsm");

// Enables or disables the Self Support.
const PREF_ENABLED = "browser.selfsupport.enabled";
// Url to open in the Self Support browser, in the urlFormatter service format.
const PREF_URL = "browser.selfsupport.url";
// Unified Telemetry status.
const PREF_TELEMETRY_UNIFIED = "toolkit.telemetry.unified";

// Controls the interval at which the self support page tries to reload in case of
// errors.
const RETRY_INTERVAL_MS = 30000;
// Maximum number of SelfSupport page load attempts in case of failure.
const MAX_RETRIES = 5;
// The delay after which to load the self-support, at startup.
const STARTUP_DELAY_MS = 5000;

const LOGGER_NAME = "Browser.SelfSupportBackend";
const PREF_BRANCH_LOG = "browser.selfsupport.log.";
const PREF_LOG_LEVEL = PREF_BRANCH_LOG + "level";
const PREF_LOG_DUMP = PREF_BRANCH_LOG + "dump";

const HTML_NS = "http://www.w3.org/1999/xhtml";
const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";

// Whether the FHR/Telemetry unification features are enabled.
// Changing this pref requires a restart.
const IS_UNIFIED_TELEMETRY = Preferences.get(PREF_TELEMETRY_UNIFIED, false);

var gLogAppenderDump = null;

this.SelfSupportBackend = Object.freeze({
  init: function () {
    SelfSupportBackendInternal.init();
  },

  uninit: function () {
    SelfSupportBackendInternal.uninit();
  },
});

var SelfSupportBackendInternal = {
  // The browser element that will load the SelfSupport page.
  _browser: null,
  // The Id of the timer triggering delayed SelfSupport page load.
  _delayedLoadTimerId: null,
  // The HiddenFrame holding the _browser element.
  _frame: null,
  _log: null,
  _progressListener: null,

  /**
   * Initializes the self support backend.
   */
  init: function () {
    this._configureLogging();

    this._log.trace("init");

    Preferences.observe(PREF_BRANCH_LOG, this._configureLogging, this);

    // Only allow to use SelfSupport if Unified Telemetry is enabled.
    let reportingEnabled = IS_UNIFIED_TELEMETRY;
    if (!reportingEnabled) {
      this._log.config("init - Disabling SelfSupport because FHR and Unified Telemetry are disabled.");
      return;
    }

    this._log.config("init - Disabling SelfSupport because UITour is disabled.");
    return;
  },

  /**
   * Shut down the self support backend, if active.
   */
  uninit: function () {
    this._log.trace("uninit");

    Preferences.ignore(PREF_BRANCH_LOG, this._configureLogging, this);

    // Cancel delayed loading, if still active, when shutting down.
    clearTimeout(this._delayedLoadTimerId);

    // Dispose of the hidden browser.
    if (this._browser !== null) {
      if (this._browser.contentWindow) {
        this._browser.contentWindow.removeEventListener("DOMWindowClose", this, true);
      }

      if (this._progressListener) {
        this._browser.removeProgressListener(this._progressListener);
        this._progressListener.destroy();
        this._progressListener = null;
      }

      this._browser.remove();
      this._browser = null;
    }

    if (this._frame) {
      this._frame.destroy();
      this._frame = null;
    }
  },

  /**
   * Handle notifications. Once all windows are created, we wait a little bit more
   * since tabs might still be loading. Then, we open the self support.
   */
  observe: function (aSubject, aTopic, aData) {
    this._log.trace("observe - Topic " + aTopic);

    if (aTopic === "sessionstore-windows-restored") {
      Services.obs.removeObserver(this, "sessionstore-windows-restored");
      this._delayedLoadTimerId = setTimeout(this._loadSelfSupport.bind(this), STARTUP_DELAY_MS);
    }
  },

  /**
   * Configure the logger based on the preferences.
   */
  _configureLogging: function() {
    if (!this._log) {
      this._log = Log.repository.getLogger(LOGGER_NAME);

      // Log messages need to go to the browser console.
      let consoleAppender = new Log.ConsoleAppender(new Log.BasicFormatter());
      this._log.addAppender(consoleAppender);
    }

    // Make sure the logger keeps up with the logging level preference.
    this._log.level = Log.Level[Preferences.get(PREF_LOG_LEVEL, "Warn")];

    // If enabled in the preferences, add a dump appender.
    let logDumping = Preferences.get(PREF_LOG_DUMP, false);
    if (logDumping != !!gLogAppenderDump) {
      if (logDumping) {
        gLogAppenderDump = new Log.DumpAppender(new Log.BasicFormatter());
        this._log.addAppender(gLogAppenderDump);
      } else {
        this._log.removeAppender(gLogAppenderDump);
        gLogAppenderDump = null;
      }
    }
  },

  /**
   * Create an hidden frame to host our |browser|, then load the SelfSupport page in it.
   * @param aURL The URL to load in the browser.
   */
  _makeHiddenBrowser: function(aURL) {
    this._frame = new HiddenFrame();
    return this._frame.get().then(aFrame => {
      let doc = aFrame.document;

      this._browser = doc.createElementNS(XUL_NS, "browser");
      this._browser.setAttribute("type", "content");
      this._browser.setAttribute("disableglobalhistory", "true");
      this._browser.setAttribute("src", aURL);

      doc.documentElement.appendChild(this._browser);
    });
  },

  handleEvent: function(aEvent) {
    this._log.trace("handleEvent - aEvent.type " + aEvent.type + ", Trusted " + aEvent.isTrusted);

    if (aEvent.type === "DOMWindowClose") {
      let window = this._browser.contentDocument.defaultView;
      let target = aEvent.target;

      if (target == window) {
        // preventDefault stops the default window.close(). We need to do that to prevent
        // Services.appShell.hiddenDOMWindow from being destroyed.
        aEvent.preventDefault();

        this.uninit();
      }
    }
  },

  /**
   * Called when the self support page correctly loads.
   */
  _pageSuccessCallback: function() {
    this._log.debug("_pageSuccessCallback - Page correctly loaded.");
    this._browser.removeProgressListener(this._progressListener);
    this._progressListener.destroy();
    this._progressListener = null;

    // Allow SelfSupportBackend to catch |window.close()| issued by the content.
    this._browser.contentWindow.addEventListener("DOMWindowClose", this, true);
  },

  /**
   * Called when the self support page fails to load.
   */
  _pageLoadErrorCallback: function() {
    this._log.info("_pageLoadErrorCallback - Too many failed load attempts. Giving up.");
    this.uninit();
  },

  /**
   * Create a browser and attach it to an hidden window. The browser will contain the
   * self support page and attempt to load the page content. If loading fails, try again
   * after an interval.
   */
  _loadSelfSupport: function() {
    // Fetch the Self Support URL from the preferences.
    let unformattedURL = Preferences.get(PREF_URL, null);
    let url = Services.urlFormatter.formatURL(unformattedURL);
    if (!url.startsWith("https:")) {
      this._log.error("_loadSelfSupport - Non HTTPS URL provided: " + url);
      return;
    }

    this._log.config("_loadSelfSupport - URL " + url);

    // Create the hidden browser.
    this._makeHiddenBrowser(url).then(() => {
      // We need to watch for load errors as well and, in case, try to reload
      // the self support page.
      const webFlags = Ci.nsIWebProgress.NOTIFY_STATE_WINDOW |
                       Ci.nsIWebProgress.NOTIFY_STATE_REQUEST |
                       Ci.nsIWebProgress.NOTIFY_LOCATION;

      this._progressListener = new ProgressListener(() => this._pageLoadErrorCallback(),
                                                    () => this._pageSuccessCallback());

      this._browser.addProgressListener(this._progressListener, webFlags);
    });
  }
};

/**
 * A progress listener object which notifies of page load error and load success
 * through callbacks. When the page fails to load, the progress listener tries to
 * reload it up to MAX_RETRIES times. The page is not loaded again immediately, but
 * after a timeout.
 *
 * @param aLoadErrorCallback Called when a page failed to load MAX_RETRIES times.
 * @param aLoadSuccessCallback Called when a page correctly loads.
 */
function ProgressListener(aLoadErrorCallback, aLoadSuccessCallback) {
  this._loadErrorCallback = aLoadErrorCallback;
  this._loadSuccessCallback = aLoadSuccessCallback;
  // The number of page loads attempted.
  this._loadAttempts = 0;
  this._log = Log.repository.getLogger(LOGGER_NAME);
  // The Id of the timer which triggers page load again in case of errors.
  this._reloadTimerId = null;
}

ProgressListener.prototype = {
  onLocationChange: function(aWebProgress, aRequest, aLocation, aFlags) {
    if (aFlags & Ci.nsIWebProgressListener.LOCATION_CHANGE_ERROR_PAGE) {
      this._log.warn("onLocationChange - There was a problem fetching the SelfSupport URL (attempt " +
                     this._loadAttempts + ").");

      // Increase the number of attempts and bail out if we failed too many times.
      this._loadAttempts++;
      if (this._loadAttempts > MAX_RETRIES) {
        this._loadErrorCallback();
        return;
      }

      // Reload the page after the retry interval expires. The interval is multiplied
      // by the number of attempted loads, so that it takes a bit more to try to reload
      // when frequently failing.
      this._reloadTimerId = setTimeout(() => {
        this._log.debug("onLocationChange - Reloading SelfSupport URL in the hidden browser.");
        aWebProgress.DOMWindow.location.reload();
      }, RETRY_INTERVAL_MS * this._loadAttempts);
    }
  },

  onStateChange: function (aWebProgress, aRequest, aFlags, aStatus) {
    if (aFlags & Ci.nsIWebProgressListener.STATE_STOP &&
        aFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK &&
        aFlags & Ci.nsIWebProgressListener.STATE_IS_WINDOW &&
        Components.isSuccessCode(aStatus)) {
      this._loadSuccessCallback();
    }
  },

  destroy: function () {
    // Make sure we don't try to reload self support when shutting down.
    clearTimeout(this._reloadTimerId);
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.nsIWebProgressListener,
                                         Ci.nsISupportsWeakReference]),
};