summaryrefslogtreecommitdiffstats
path: root/services/sync/modules/engines/extension-storage.sys.mjs
blob: d2671978c850682df30afefef72d5c5a1cd6f09b (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
/* 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/. */

import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";

import {
  BridgedEngine,
  BridgeWrapperXPCOM,
  LogAdapter,
} from "resource://services-sync/bridged_engine.sys.mjs";
import { SyncEngine, Tracker } from "resource://services-sync/engines.sys.mjs";

const lazy = {};

ChromeUtils.defineESModuleGetters(lazy, {
  MULTI_DEVICE_THRESHOLD: "resource://services-sync/constants.sys.mjs",
  Observers: "resource://services-common/observers.sys.mjs",
  SCORE_INCREMENT_MEDIUM: "resource://services-sync/constants.sys.mjs",
  Svc: "resource://services-sync/util.sys.mjs",
  extensionStorageSync: "resource://gre/modules/ExtensionStorageSync.sys.mjs",

  extensionStorageSyncKinto:
    "resource://gre/modules/ExtensionStorageSyncKinto.sys.mjs",
});

XPCOMUtils.defineLazyServiceGetter(
  lazy,
  "StorageSyncService",
  "@mozilla.org/extensions/storage/sync;1",
  "nsIInterfaceRequestor"
);

const PREF_FORCE_ENABLE = "engine.extension-storage.force";

// A helper to indicate whether extension-storage is enabled - it's based on
// the "addons" pref. The same logic is shared between both engine impls.
function getEngineEnabled() {
  // By default, we sync extension storage if we sync addons. This
  // lets us simplify the UX since users probably don't consider
  // "extension preferences" a separate category of syncing.
  // However, we also respect engine.extension-storage.force, which
  // can be set to true or false, if a power user wants to customize
  // the behavior despite the lack of UI.
  if (
    lazy.Svc.PrefBranch.getPrefType(PREF_FORCE_ENABLE) !=
    Ci.nsIPrefBranch.PREF_INVALID
  ) {
    return lazy.Svc.PrefBranch.getBoolPref(PREF_FORCE_ENABLE);
  }
  return lazy.Svc.PrefBranch.getBoolPref("engine.addons", false);
}

function setEngineEnabled(enabled) {
  // This will be called by the engine manager when declined on another device.
  // Things will go a bit pear-shaped if the engine manager tries to end up
  // with 'addons' and 'extension-storage' in different states - however, this
  // *can* happen given we support the `engine.extension-storage.force`
  // preference. So if that pref exists, we set it to this value. If that pref
  // doesn't exist, we just ignore it and hope that the 'addons' engine is also
  // going to be set to the same state.
  if (
    lazy.Svc.PrefBranch.getPrefType(PREF_FORCE_ENABLE) !=
    Ci.nsIPrefBranch.PREF_INVALID
  ) {
    lazy.Svc.PrefBranch.setBoolPref(PREF_FORCE_ENABLE, enabled);
  }
}

// A "bridged engine" to our webext-storage component.
export function ExtensionStorageEngineBridge(service) {
  this.component = lazy.StorageSyncService.getInterface(
    Ci.mozIBridgedSyncEngine
  );
  BridgedEngine.call(this, "Extension-Storage", service);
  this._bridge = new BridgeWrapperXPCOM(this.component);

  let app_services_logger = Cc["@mozilla.org/appservices/logger;1"].getService(
    Ci.mozIAppServicesLogger
  );
  let logger_target = "app-services:webext_storage:sync";
  app_services_logger.register(logger_target, new LogAdapter(this._log));
}

ExtensionStorageEngineBridge.prototype = {
  syncPriority: 10,

  // Used to override the engine name in telemetry, so that we can distinguish .
  overrideTelemetryName: "rust-webext-storage",

  _notifyPendingChanges() {
    return new Promise(resolve => {
      this.component
        .QueryInterface(Ci.mozISyncedExtensionStorageArea)
        .fetchPendingSyncChanges({
          QueryInterface: ChromeUtils.generateQI([
            "mozIExtensionStorageListener",
            "mozIExtensionStorageCallback",
          ]),
          onChanged: (extId, json) => {
            try {
              lazy.extensionStorageSync.notifyListeners(
                extId,
                JSON.parse(json)
              );
            } catch (ex) {
              this._log.warn(
                `Error notifying change listeners for ${extId}`,
                ex
              );
            }
          },
          handleSuccess: resolve,
          handleError: (code, message) => {
            this._log.warn(
              "Error fetching pending synced changes",
              message,
              code
            );
            resolve();
          },
        });
    });
  },

  _takeMigrationInfo() {
    return new Promise((resolve, reject) => {
      this.component
        .QueryInterface(Ci.mozIExtensionStorageArea)
        .takeMigrationInfo({
          QueryInterface: ChromeUtils.generateQI([
            "mozIExtensionStorageCallback",
          ]),
          handleSuccess: result => {
            resolve(result ? JSON.parse(result) : null);
          },
          handleError: (code, message) => {
            this._log.warn("Error fetching migration info", message, code);
            // `takeMigrationInfo` doesn't actually perform the migration,
            // just reads (and clears) any data stored in the DB from the
            // previous migration.
            //
            // Any errors here are very likely occurring a good while
            // after the migration ran, so we just warn and pretend
            // nothing was there.
            resolve(null);
          },
        });
    });
  },

  async _syncStartup() {
    let result = await super._syncStartup();
    let info = await this._takeMigrationInfo();
    if (info) {
      lazy.Observers.notify(
        "weave:telemetry:migration",
        info,
        "webext-storage"
      );
    }
    return result;
  },

  async _processIncoming() {
    await super._processIncoming();
    try {
      await this._notifyPendingChanges();
    } catch (ex) {
      // Failing to notify `storage.onChanged` observers is bad, but shouldn't
      // interrupt syncing.
      this._log.warn("Error notifying about synced changes", ex);
    }
  },

  get enabled() {
    return getEngineEnabled();
  },
  set enabled(enabled) {
    setEngineEnabled(enabled);
  },
};
Object.setPrototypeOf(
  ExtensionStorageEngineBridge.prototype,
  BridgedEngine.prototype
);

/**
 *****************************************************************************
 *
 * Deprecated support for Kinto
 *
 *****************************************************************************
 */

/**
 * The Engine that manages syncing for the web extension "storage"
 * API, and in particular ext.storage.sync.
 *
 * ext.storage.sync is implemented using Kinto, so it has mechanisms
 * for syncing that we do not need to integrate in the Firefox Sync
 * framework, so this is something of a stub.
 */
export function ExtensionStorageEngineKinto(service) {
  SyncEngine.call(this, "Extension-Storage", service);
  XPCOMUtils.defineLazyPreferenceGetter(
    this,
    "_skipPercentageChance",
    "services.sync.extension-storage.skipPercentageChance",
    0
  );
}

ExtensionStorageEngineKinto.prototype = {
  _trackerObj: ExtensionStorageTracker,
  // we don't need these since we implement our own sync logic
  _storeObj: undefined,
  _recordObj: undefined,

  syncPriority: 10,
  allowSkippedRecord: false,

  async _sync() {
    return lazy.extensionStorageSyncKinto.syncAll();
  },

  get enabled() {
    return getEngineEnabled();
  },
  // We only need the enabled setter for the edge-case where info/collections
  // has `extension-storage` - which could happen if the pref to flip the new
  // engine on was once set but no longer is.
  set enabled(enabled) {
    setEngineEnabled(enabled);
  },

  _wipeClient() {
    return lazy.extensionStorageSyncKinto.clearAll();
  },

  shouldSkipSync(syncReason) {
    if (syncReason == "user" || syncReason == "startup") {
      this._log.info(
        `Not skipping extension storage sync: reason == ${syncReason}`
      );
      // Always sync if a user clicks the button, or if we're starting up.
      return false;
    }
    // Ensure this wouldn't cause a resync...
    if (this._tracker.score >= lazy.MULTI_DEVICE_THRESHOLD) {
      this._log.info(
        "Not skipping extension storage sync: Would trigger resync anyway"
      );
      return false;
    }

    let probability = this._skipPercentageChance / 100.0;
    // Math.random() returns a value in the interval [0, 1), so `>` is correct:
    // if `probability` is 1 skip every time, and if it's 0, never skip.
    let shouldSkip = probability > Math.random();

    this._log.info(
      `Skipping extension-storage sync with a chance of ${probability}: ${shouldSkip}`
    );
    return shouldSkip;
  },
};
Object.setPrototypeOf(
  ExtensionStorageEngineKinto.prototype,
  SyncEngine.prototype
);

function ExtensionStorageTracker(name, engine) {
  Tracker.call(this, name, engine);
  this._ignoreAll = false;
}
ExtensionStorageTracker.prototype = {
  get ignoreAll() {
    return this._ignoreAll;
  },

  set ignoreAll(value) {
    this._ignoreAll = value;
  },

  onStart() {
    lazy.Svc.Obs.add("ext.storage.sync-changed", this.asyncObserver);
  },

  onStop() {
    lazy.Svc.Obs.remove("ext.storage.sync-changed", this.asyncObserver);
  },

  async observe(subject, topic, data) {
    if (this.ignoreAll) {
      return;
    }

    if (topic !== "ext.storage.sync-changed") {
      return;
    }

    // Single adds, removes and changes are not so important on their
    // own, so let's just increment score a bit.
    this.score += lazy.SCORE_INCREMENT_MEDIUM;
  },
};
Object.setPrototypeOf(ExtensionStorageTracker.prototype, Tracker.prototype);