summaryrefslogtreecommitdiffstats
path: root/dom/push/PushService.sys.mjs
blob: 1add65992f035ccae2664cf8fe36d3e5230cceea (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
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
/* 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 { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";

import { clearTimeout, setTimeout } from "resource://gre/modules/Timer.sys.mjs";
import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";

export var PushServiceWebSocket;
export var PushServiceHttp2;

const lazy = {};

XPCOMUtils.defineLazyServiceGetter(
  lazy,
  "gPushNotifier",
  "@mozilla.org/push/Notifier;1",
  "nsIPushNotifier"
);
ChromeUtils.defineESModuleGetters(lazy, {
  PushCrypto: "resource://gre/modules/PushCrypto.sys.mjs",
  pushBroadcastService: "resource://gre/modules/PushBroadcastService.sys.mjs",
});

const CONNECTION_PROTOCOLS = (function () {
  if ("android" != AppConstants.MOZ_WIDGET_TOOLKIT) {
    ({ PushServiceWebSocket } = ChromeUtils.importESModule(
      "resource://gre/modules/PushServiceWebSocket.sys.mjs"
    ));
    ({ PushServiceHttp2 } = ChromeUtils.importESModule(
      "resource://gre/modules/PushServiceHttp2.sys.mjs"
    ));
    return [PushServiceWebSocket, PushServiceHttp2];
  }
  return [];
})();

ChromeUtils.defineLazyGetter(lazy, "console", () => {
  let { ConsoleAPI } = ChromeUtils.importESModule(
    "resource://gre/modules/Console.sys.mjs"
  );
  return new ConsoleAPI({
    maxLogLevelPref: "dom.push.loglevel",
    prefix: "PushService",
  });
});

const prefs = Services.prefs.getBranch("dom.push.");

const PUSH_SERVICE_UNINIT = 0;
const PUSH_SERVICE_INIT = 1; // No serverURI
const PUSH_SERVICE_ACTIVATING = 2; // activating db
const PUSH_SERVICE_CONNECTION_DISABLE = 3;
const PUSH_SERVICE_ACTIVE_OFFLINE = 4;
const PUSH_SERVICE_RUNNING = 5;

/**
 * State is change only in couple of functions:
 *   init - change state to PUSH_SERVICE_INIT if state was PUSH_SERVICE_UNINIT
 *   changeServerURL - change state to PUSH_SERVICE_ACTIVATING if serverURL
 *                     present or PUSH_SERVICE_INIT if not present.
 *   changeStateConnectionEnabledEvent - it is call on pref change or during
 *                                       the service activation and it can
 *                                       change state to
 *                                       PUSH_SERVICE_CONNECTION_DISABLE
 *   changeStateOfflineEvent - it is called when offline state changes or during
 *                             the service activation and it change state to
 *                             PUSH_SERVICE_ACTIVE_OFFLINE or
 *                             PUSH_SERVICE_RUNNING.
 *   uninit - change state to PUSH_SERVICE_UNINIT.
 **/

// This is for starting and stopping service.
const STARTING_SERVICE_EVENT = 0;
const CHANGING_SERVICE_EVENT = 1;
const STOPPING_SERVICE_EVENT = 2;
const UNINIT_EVENT = 3;

// Returns the backend for the given server URI.
function getServiceForServerURI(uri) {
  // Insecure server URLs are allowed for development and testing.
  let allowInsecure = prefs.getBoolPref(
    "testing.allowInsecureServerURL",
    false
  );
  if (AppConstants.MOZ_WIDGET_TOOLKIT == "android") {
    if (uri.scheme == "https" || (allowInsecure && uri.scheme == "http")) {
      return CONNECTION_PROTOCOLS;
    }
    return null;
  }
  if (uri.scheme == "wss" || (allowInsecure && uri.scheme == "ws")) {
    return PushServiceWebSocket;
  }
  if (uri.scheme == "https" || (allowInsecure && uri.scheme == "http")) {
    return PushServiceHttp2;
  }
  return null;
}

/**
 * Annotates an error with an XPCOM result code. We use this helper
 * instead of `Components.Exception` because the latter can assert in
 * `nsXPCComponents_Exception::HasInstance` when inspected at shutdown.
 */
function errorWithResult(message, result = Cr.NS_ERROR_FAILURE) {
  let error = new Error(message);
  error.result = result;
  return error;
}

/**
 * The implementation of the push system. It uses WebSockets
 * (PushServiceWebSocket) to communicate with the server and PushDB (IndexedDB)
 * for persistence.
 */
export var PushService = {
  _service: null,
  _state: PUSH_SERVICE_UNINIT,
  _db: null,
  _options: null,
  _visibleNotifications: new Map(),

  // Callback that is called after attempting to
  // reduce the quota for a record. Used for testing purposes.
  _updateQuotaTestCallback: null,

  // Set of timeout ID of tasks to reduce quota.
  _updateQuotaTimeouts: new Set(),

  // When serverURI changes (this is used for testing), db is cleaned up and a
  // a new db is started. This events must be sequential.
  _stateChangeProcessQueue: null,
  _stateChangeProcessEnqueue(op) {
    if (!this._stateChangeProcessQueue) {
      this._stateChangeProcessQueue = Promise.resolve();
    }

    this._stateChangeProcessQueue = this._stateChangeProcessQueue
      .then(op)
      .catch(error => {
        lazy.console.error(
          "stateChangeProcessEnqueue: Error transitioning state",
          error
        );
        return this._shutdownService();
      })
      .catch(error => {
        lazy.console.error(
          "stateChangeProcessEnqueue: Error shutting down service",
          error
        );
      });
    return this._stateChangeProcessQueue;
  },

  // Pending request. If a worker try to register for the same scope again, do
  // not send a new registration request. Therefore we need queue of pending
  // register requests. This is the list of scopes which pending registration.
  _pendingRegisterRequest: {},
  _notifyActivated: null,
  _activated: null,
  _checkActivated() {
    if (this._state < PUSH_SERVICE_ACTIVATING) {
      return Promise.reject(new Error("Push service not active"));
    }
    if (this._state > PUSH_SERVICE_ACTIVATING) {
      return Promise.resolve();
    }
    if (!this._activated) {
      this._activated = new Promise((resolve, reject) => {
        this._notifyActivated = { resolve, reject };
      });
    }
    return this._activated;
  },

  _makePendingKey(aPageRecord) {
    return aPageRecord.scope + "|" + aPageRecord.originAttributes;
  },

  _lookupOrPutPendingRequest(aPageRecord) {
    let key = this._makePendingKey(aPageRecord);
    if (this._pendingRegisterRequest[key]) {
      return this._pendingRegisterRequest[key];
    }

    return (this._pendingRegisterRequest[key] =
      this._registerWithServer(aPageRecord));
  },

  _deletePendingRequest(aPageRecord) {
    let key = this._makePendingKey(aPageRecord);
    if (this._pendingRegisterRequest[key]) {
      delete this._pendingRegisterRequest[key];
    }
  },

  _setState(aNewState) {
    lazy.console.debug(
      "setState()",
      "new state",
      aNewState,
      "old state",
      this._state
    );

    if (this._state == aNewState) {
      return;
    }

    if (this._state == PUSH_SERVICE_ACTIVATING) {
      // It is not important what is the new state as soon as we leave
      // PUSH_SERVICE_ACTIVATING
      if (this._notifyActivated) {
        if (aNewState < PUSH_SERVICE_ACTIVATING) {
          this._notifyActivated.reject(new Error("Push service not active"));
        } else {
          this._notifyActivated.resolve();
        }
      }
      this._notifyActivated = null;
      this._activated = null;
    }
    this._state = aNewState;
  },

  async _changeStateOfflineEvent(offline, calledFromConnEnabledEvent) {
    lazy.console.debug("changeStateOfflineEvent()", offline);

    if (
      this._state < PUSH_SERVICE_ACTIVE_OFFLINE &&
      this._state != PUSH_SERVICE_ACTIVATING &&
      !calledFromConnEnabledEvent
    ) {
      return;
    }

    if (offline) {
      if (this._state == PUSH_SERVICE_RUNNING) {
        this._service.disconnect();
      }
      this._setState(PUSH_SERVICE_ACTIVE_OFFLINE);
      return;
    }

    if (this._state == PUSH_SERVICE_RUNNING) {
      // PushService was not in the offline state, but got notification to
      // go online (a offline notification has not been sent).
      // Disconnect first.
      this._service.disconnect();
    }

    let broadcastListeners = await lazy.pushBroadcastService.getListeners();

    // In principle, a listener could be added to the
    // pushBroadcastService here, after we have gotten listeners and
    // before we're RUNNING, but this can't happen in practice because
    // the only caller that can add listeners is PushBroadcastService,
    // and it waits on the same promise we are before it can add
    // listeners. If PushBroadcastService gets woken first, it will
    // update the value that is eventually returned from
    // getListeners.
    this._setState(PUSH_SERVICE_RUNNING);

    this._service.connect(broadcastListeners);
  },

  _changeStateConnectionEnabledEvent(enabled) {
    lazy.console.debug("changeStateConnectionEnabledEvent()", enabled);

    if (
      this._state < PUSH_SERVICE_CONNECTION_DISABLE &&
      this._state != PUSH_SERVICE_ACTIVATING
    ) {
      return Promise.resolve();
    }

    if (enabled) {
      return this._changeStateOfflineEvent(Services.io.offline, true);
    }

    if (this._state == PUSH_SERVICE_RUNNING) {
      this._service.disconnect();
    }
    this._setState(PUSH_SERVICE_CONNECTION_DISABLE);
    return Promise.resolve();
  },

  // Used for testing.
  changeTestServer(url, options = {}) {
    lazy.console.debug("changeTestServer()");

    return this._stateChangeProcessEnqueue(_ => {
      if (this._state < PUSH_SERVICE_ACTIVATING) {
        lazy.console.debug("changeTestServer: PushService not activated?");
        return Promise.resolve();
      }

      return this._changeServerURL(url, CHANGING_SERVICE_EVENT, options);
    });
  },

  observe: function observe(aSubject, aTopic, aData) {
    switch (aTopic) {
      /*
       * We need to call uninit() on shutdown to clean up things that modules
       * aren't very good at automatically cleaning up, so we don't get shutdown
       * leaks on browser shutdown.
       */
      case "quit-application":
        this.uninit();
        break;
      case "network:offline-status-changed":
        this._stateChangeProcessEnqueue(_ =>
          this._changeStateOfflineEvent(aData === "offline", false)
        );
        break;

      case "nsPref:changed":
        if (aData == "serverURL") {
          lazy.console.debug(
            "observe: dom.push.serverURL changed for websocket",
            prefs.getStringPref("serverURL")
          );
          this._stateChangeProcessEnqueue(_ =>
            this._changeServerURL(
              prefs.getStringPref("serverURL"),
              CHANGING_SERVICE_EVENT
            )
          );
        } else if (aData == "connection.enabled") {
          this._stateChangeProcessEnqueue(_ =>
            this._changeStateConnectionEnabledEvent(
              prefs.getBoolPref("connection.enabled")
            )
          );
        }
        break;

      case "idle-daily":
        this._dropExpiredRegistrations().catch(error => {
          lazy.console.error(
            "Failed to drop expired registrations on idle",
            error
          );
        });
        break;

      case "perm-changed":
        this._onPermissionChange(aSubject, aData).catch(error => {
          lazy.console.error(
            "onPermissionChange: Error updating registrations:",
            error
          );
        });
        break;

      case "clear-origin-attributes-data":
        this._clearOriginData(aData).catch(error => {
          lazy.console.error(
            "clearOriginData: Error clearing origin data:",
            error
          );
        });
        break;
    }
  },

  _clearOriginData(data) {
    lazy.console.log("clearOriginData()");

    if (!data) {
      return Promise.resolve();
    }

    let pattern = JSON.parse(data);
    return this._dropRegistrationsIf(record =>
      record.matchesOriginAttributes(pattern)
    );
  },

  /**
   * Sends an unregister request to the server in the background. If the
   * service is not connected, this function is a no-op.
   *
   * @param {PushRecord} record The record to unregister.
   * @param {Number} reason An `nsIPushErrorReporter` unsubscribe reason,
   *  indicating why this record was removed.
   */
  _backgroundUnregister(record, reason) {
    lazy.console.debug("backgroundUnregister()");

    if (!this._service.isConnected() || !record) {
      return;
    }

    lazy.console.debug("backgroundUnregister: Notifying server", record);
    this._sendUnregister(record, reason)
      .then(() => {
        lazy.gPushNotifier.notifySubscriptionModified(
          record.scope,
          record.principal
        );
      })
      .catch(e => {
        lazy.console.error("backgroundUnregister: Error notifying server", e);
      });
  },

  _findService(serverURL) {
    lazy.console.debug("findService()");

    if (!serverURL) {
      lazy.console.warn("findService: No dom.push.serverURL found");
      return [];
    }

    let uri;
    try {
      uri = Services.io.newURI(serverURL);
    } catch (e) {
      lazy.console.warn(
        "findService: Error creating valid URI from",
        "dom.push.serverURL",
        serverURL
      );
      return [];
    }

    let service = getServiceForServerURI(uri);
    return [service, uri];
  },

  _changeServerURL(serverURI, event, options = {}) {
    lazy.console.debug("changeServerURL()");

    switch (event) {
      case UNINIT_EVENT:
        return this._stopService(event);

      case STARTING_SERVICE_EVENT: {
        let [service, uri] = this._findService(serverURI);
        if (!service) {
          this._setState(PUSH_SERVICE_INIT);
          return Promise.resolve();
        }
        return this._startService(service, uri, options).then(_ =>
          this._changeStateConnectionEnabledEvent(
            prefs.getBoolPref("connection.enabled")
          )
        );
      }
      case CHANGING_SERVICE_EVENT:
        let [service, uri] = this._findService(serverURI);
        if (service) {
          if (this._state == PUSH_SERVICE_INIT) {
            this._setState(PUSH_SERVICE_ACTIVATING);
            // The service has not been running - start it.
            return this._startService(service, uri, options).then(_ =>
              this._changeStateConnectionEnabledEvent(
                prefs.getBoolPref("connection.enabled")
              )
            );
          }
          this._setState(PUSH_SERVICE_ACTIVATING);
          // If we already had running service - stop service, start the new
          // one and check connection.enabled and offline state(offline state
          // check is called in changeStateConnectionEnabledEvent function)
          return this._stopService(CHANGING_SERVICE_EVENT)
            .then(_ => this._startService(service, uri, options))
            .then(_ =>
              this._changeStateConnectionEnabledEvent(
                prefs.getBoolPref("connection.enabled")
              )
            );
        }
        if (this._state == PUSH_SERVICE_INIT) {
          return Promise.resolve();
        }
        // The new serverUri is empty or misconfigured - stop service.
        this._setState(PUSH_SERVICE_INIT);
        return this._stopService(STOPPING_SERVICE_EVENT);

      default:
        lazy.console.error("Unexpected event in _changeServerURL", event);
        return Promise.reject(new Error(`Unexpected event ${event}`));
    }
  },

  /**
   * PushService initialization is divided into 4 parts:
   * init() - start listening for quit-application and serverURL changes.
   *          state is change to PUSH_SERVICE_INIT
   * startService() - if serverURL is present this function is called. It starts
   *                  listening for broadcasted messages, starts db and
   *                  PushService connection (WebSocket).
   *                  state is change to PUSH_SERVICE_ACTIVATING.
   * startObservers() - start other observers.
   * changeStateConnectionEnabledEvent  - checks prefs and offline state.
   *                                      It changes state to:
   *                                        PUSH_SERVICE_RUNNING,
   *                                        PUSH_SERVICE_ACTIVE_OFFLINE or
   *                                        PUSH_SERVICE_CONNECTION_DISABLE.
   */
  async init(options = {}) {
    lazy.console.debug("init()");

    if (this._state > PUSH_SERVICE_UNINIT) {
      return;
    }

    this._setState(PUSH_SERVICE_ACTIVATING);

    prefs.addObserver("serverURL", this);
    Services.obs.addObserver(this, "quit-application");

    if (options.serverURI) {
      // this is use for xpcshell test.

      await this._stateChangeProcessEnqueue(_ =>
        this._changeServerURL(
          options.serverURI,
          STARTING_SERVICE_EVENT,
          options
        )
      );
    } else {
      // This is only used for testing. Different tests require connecting to
      // slightly different URLs.
      await this._stateChangeProcessEnqueue(_ =>
        this._changeServerURL(
          prefs.getStringPref("serverURL"),
          STARTING_SERVICE_EVENT
        )
      );
    }
  },

  _startObservers() {
    lazy.console.debug("startObservers()");

    if (this._state != PUSH_SERVICE_ACTIVATING) {
      return;
    }

    Services.obs.addObserver(this, "clear-origin-attributes-data");

    // The offline-status-changed event is used to know
    // when to (dis)connect. It may not fire if the underlying OS changes
    // networks; in such a case we rely on timeout.
    Services.obs.addObserver(this, "network:offline-status-changed");

    // Used to monitor if the user wishes to disable Push.
    prefs.addObserver("connection.enabled", this);

    // Prunes expired registrations and notifies dormant service workers.
    Services.obs.addObserver(this, "idle-daily");

    // Prunes registrations for sites for which the user revokes push
    // permissions.
    Services.obs.addObserver(this, "perm-changed");
  },

  _startService(service, serverURI, options) {
    lazy.console.debug("startService()");

    if (this._state != PUSH_SERVICE_ACTIVATING) {
      return Promise.reject();
    }

    this._service = service;

    this._db = options.db;
    if (!this._db) {
      this._db = this._service.newPushDB();
    }

    return this._service.init(options, this, serverURI).then(() => {
      this._startObservers();
      return this._dropExpiredRegistrations();
    });
  },

  /**
   * PushService uninitialization is divided into 3 parts:
   * stopObservers() - stot observers started in startObservers.
   * stopService() - It stops listening for broadcasted messages, stops db and
   *                 PushService connection (WebSocket).
   *                 state is changed to PUSH_SERVICE_INIT.
   * uninit() - stop listening for quit-application and serverURL changes.
   *            state is change to PUSH_SERVICE_UNINIT
   */
  _stopService(event) {
    lazy.console.debug("stopService()");

    if (this._state < PUSH_SERVICE_ACTIVATING) {
      return Promise.resolve();
    }

    this._stopObservers();

    this._service.disconnect();
    this._service.uninit();
    this._service = null;

    this._updateQuotaTimeouts.forEach(timeoutID => clearTimeout(timeoutID));
    this._updateQuotaTimeouts.clear();

    if (!this._db) {
      return Promise.resolve();
    }
    if (event == UNINIT_EVENT) {
      // If it is uninitialized just close db.
      this._db.close();
      this._db = null;
      return Promise.resolve();
    }

    return this.dropUnexpiredRegistrations().then(
      _ => {
        this._db.close();
        this._db = null;
      },
      () => {
        this._db.close();
        this._db = null;
      }
    );
  },

  _stopObservers() {
    lazy.console.debug("stopObservers()");

    if (this._state < PUSH_SERVICE_ACTIVATING) {
      return;
    }

    prefs.removeObserver("connection.enabled", this);

    Services.obs.removeObserver(this, "network:offline-status-changed");
    Services.obs.removeObserver(this, "clear-origin-attributes-data");
    Services.obs.removeObserver(this, "idle-daily");
    Services.obs.removeObserver(this, "perm-changed");
  },

  _shutdownService() {
    let promiseChangeURL = this._changeServerURL("", UNINIT_EVENT);
    this._setState(PUSH_SERVICE_UNINIT);
    lazy.console.debug("shutdownService: shutdown complete!");
    return promiseChangeURL;
  },

  async uninit() {
    lazy.console.debug("uninit()");

    if (this._state == PUSH_SERVICE_UNINIT) {
      return;
    }

    prefs.removeObserver("serverURL", this);
    Services.obs.removeObserver(this, "quit-application");

    await this._stateChangeProcessEnqueue(_ => this._shutdownService());
  },

  /**
   * Drops all active registrations and notifies the associated service
   * workers. This function is called when the user switches Push servers,
   * or when the server invalidates all existing registrations.
   *
   * We ignore expired registrations because they're already handled in other
   * code paths. Registrations that expired after exceeding their quotas are
   * evicted at startup, or on the next `idle-daily` event. Registrations that
   * expired because the user revoked the notification permission are evicted
   * once the permission is reinstated.
   */
  dropUnexpiredRegistrations() {
    return this._db.clearIf(record => {
      if (record.isExpired()) {
        return false;
      }
      this._notifySubscriptionChangeObservers(record);
      return true;
    });
  },

  _notifySubscriptionChangeObservers(record) {
    if (!record) {
      return;
    }
    lazy.gPushNotifier.notifySubscriptionChange(record.scope, record.principal);
  },

  /**
   * Drops a registration and notifies the associated service worker. If the
   * registration does not exist, this function is a no-op.
   *
   * @param {String} keyID The registration ID to remove.
   * @returns {Promise} Resolves once the worker has been notified.
   */
  dropRegistrationAndNotifyApp(aKeyID) {
    return this._db
      .delete(aKeyID)
      .then(record => this._notifySubscriptionChangeObservers(record));
  },

  /**
   * Replaces an existing registration and notifies the associated service
   * worker.
   *
   * @param {String} aOldKey The registration ID to replace.
   * @param {PushRecord} aNewRecord The new record.
   * @returns {Promise} Resolves once the worker has been notified.
   */
  updateRegistrationAndNotifyApp(aOldKey, aNewRecord) {
    return this.updateRecordAndNotifyApp(aOldKey, _ => aNewRecord);
  },
  /**
   * Updates a registration and notifies the associated service worker.
   *
   * @param {String} keyID The registration ID to update.
   * @param {Function} updateFunc Returns the updated record.
   * @returns {Promise} Resolves with the updated record once the worker
   *  has been notified.
   */
  updateRecordAndNotifyApp(aKeyID, aUpdateFunc) {
    return this._db.update(aKeyID, aUpdateFunc).then(record => {
      this._notifySubscriptionChangeObservers(record);
      return record;
    });
  },

  ensureCrypto(record) {
    if (
      record.hasAuthenticationSecret() &&
      record.p256dhPublicKey &&
      record.p256dhPrivateKey
    ) {
      return Promise.resolve(record);
    }

    let keygen = Promise.resolve([]);
    if (!record.p256dhPublicKey || !record.p256dhPrivateKey) {
      keygen = lazy.PushCrypto.generateKeys();
    }
    // We do not have a encryption key. so we need to generate it. This
    // is only going to happen on db upgrade from version 4 to higher.
    return keygen.then(
      ([pubKey, privKey]) => {
        return this.updateRecordAndNotifyApp(record.keyID, record => {
          if (!record.p256dhPublicKey || !record.p256dhPrivateKey) {
            record.p256dhPublicKey = pubKey;
            record.p256dhPrivateKey = privKey;
          }
          if (!record.hasAuthenticationSecret()) {
            record.authenticationSecret =
              lazy.PushCrypto.generateAuthenticationSecret();
          }
          return record;
        });
      },
      error => {
        return this.dropRegistrationAndNotifyApp(record.keyID).then(() =>
          Promise.reject(error)
        );
      }
    );
  },

  /**
   * Dispatches an incoming message to a service worker, recalculating the
   * quota for the associated push registration. If the quota is exceeded,
   * the registration and message will be dropped, and the worker will not
   * be notified.
   *
   * @param {String} keyID The push registration ID.
   * @param {String} messageID The message ID, used to report service worker
   *  delivery failures. For Web Push messages, this is the version. If empty,
   *  failures will not be reported.
   * @param {Object} headers The encryption headers.
   * @param {ArrayBuffer|Uint8Array} data The encrypted message data.
   * @param {Function} updateFunc A function that receives the existing
   *  registration record as its argument, and returns a new record. If the
   *  function returns `null` or `undefined`, the record will not be updated.
   *  `PushServiceWebSocket` uses this to drop incoming updates with older
   *  versions.
   * @returns {Promise} Resolves with an `nsIPushErrorReporter` ack status
   *  code, indicating whether the message was delivered successfully.
   */
  receivedPushMessage(keyID, messageID, headers, data, updateFunc) {
    lazy.console.debug("receivedPushMessage()");

    return this._updateRecordAfterPush(keyID, updateFunc)
      .then(record => {
        if (record.quotaApplies()) {
          // Update quota after the delay, at which point
          // we check for visible notifications.
          let timeoutID = setTimeout(_ => {
            this._updateQuota(keyID);
            if (!this._updateQuotaTimeouts.delete(timeoutID)) {
              lazy.console.debug(
                "receivedPushMessage: quota update timeout missing?"
              );
            }
          }, prefs.getIntPref("quotaUpdateDelay"));
          this._updateQuotaTimeouts.add(timeoutID);
        }
        return this._decryptAndNotifyApp(record, messageID, headers, data);
      })
      .catch(error => {
        lazy.console.error("receivedPushMessage: Error notifying app", error);
        return Ci.nsIPushErrorReporter.ACK_NOT_DELIVERED;
      });
  },

  /**
   * Dispatches a broadcast notification to the BroadcastService.
   *
   * @param {Object} message The reply received by PushServiceWebSocket
   * @param {Object} context Additional information about the context in which the
   *  notification was received.
   */
  receivedBroadcastMessage(message, context) {
    lazy.pushBroadcastService
      .receivedBroadcastMessage(message.broadcasts, context)
      .catch(e => {
        lazy.console.error(e);
      });
  },

  /**
   * Updates a registration record after receiving a push message.
   *
   * @param {String} keyID The push registration ID.
   * @param {Function} updateFunc The function passed to `receivedPushMessage`.
   * @returns {Promise} Resolves with the updated record, or rejects if the
   *  record was not updated.
   */
  _updateRecordAfterPush(keyID, updateFunc) {
    return this.getByKeyID(keyID)
      .then(record => {
        if (!record) {
          throw new Error("No record for key ID " + keyID);
        }
        return record
          .getLastVisit()
          .then(lastVisit => {
            // As a special case, don't notify the service worker if the user
            // cleared their history.
            if (!isFinite(lastVisit)) {
              throw new Error("Ignoring message sent to unvisited origin");
            }
            return lastVisit;
          })
          .then(lastVisit => {
            // Update the record, resetting the quota if the user has visited the
            // site since the last push.
            return this._db.update(keyID, record => {
              let newRecord = updateFunc(record);
              if (!newRecord) {
                return null;
              }
              // Because `unregister` is advisory only, we can still receive messages
              // for stale Simple Push registrations from the server. To work around
              // this, we check if the record has expired before *and* after updating
              // the quota.
              if (newRecord.isExpired()) {
                return null;
              }
              newRecord.receivedPush(lastVisit);
              return newRecord;
            });
          });
      })
      .then(record => {
        lazy.gPushNotifier.notifySubscriptionModified(
          record.scope,
          record.principal
        );
        return record;
      });
  },

  /**
   * Decrypts an incoming message and notifies the associated service worker.
   *
   * @param {PushRecord} record The receiving registration.
   * @param {String} messageID The message ID.
   * @param {Object} headers The encryption headers.
   * @param {ArrayBuffer|Uint8Array} data The encrypted message data.
   * @returns {Promise} Resolves with an ack status code.
   */
  _decryptAndNotifyApp(record, messageID, headers, data) {
    return lazy.PushCrypto.decrypt(
      record.p256dhPrivateKey,
      record.p256dhPublicKey,
      record.authenticationSecret,
      headers,
      data
    ).then(
      message => this._notifyApp(record, messageID, message),
      error => {
        lazy.console.warn(
          "decryptAndNotifyApp: Error decrypting message",
          record.scope,
          messageID,
          error
        );

        let message = error.format(record.scope);
        lazy.gPushNotifier.notifyError(
          record.scope,
          record.principal,
          message,
          Ci.nsIScriptError.errorFlag
        );
        return Ci.nsIPushErrorReporter.ACK_DECRYPTION_ERROR;
      }
    );
  },

  _updateQuota(keyID) {
    lazy.console.debug("updateQuota()");

    this._db
      .update(keyID, record => {
        // Record may have expired from an earlier quota update.
        if (record.isExpired()) {
          lazy.console.debug(
            "updateQuota: Trying to update quota for expired record",
            record
          );
          return null;
        }
        // If there are visible notifications, don't apply the quota penalty
        // for the message.
        if (record.uri && !this._visibleNotifications.has(record.uri.prePath)) {
          record.reduceQuota();
        }
        return record;
      })
      .then(record => {
        if (record.isExpired()) {
          // Drop the registration in the background. If the user returns to the
          // site, the service worker will be notified on the next `idle-daily`
          // event.
          this._backgroundUnregister(
            record,
            Ci.nsIPushErrorReporter.UNSUBSCRIBE_QUOTA_EXCEEDED
          );
        } else {
          lazy.gPushNotifier.notifySubscriptionModified(
            record.scope,
            record.principal
          );
        }
        if (this._updateQuotaTestCallback) {
          // Callback so that test may be notified when the quota update is complete.
          this._updateQuotaTestCallback();
        }
      })
      .catch(error => {
        lazy.console.debug(
          "updateQuota: Error while trying to update quota",
          error
        );
      });
  },

  notificationForOriginShown(origin) {
    lazy.console.debug("notificationForOriginShown()", origin);
    let count;
    if (this._visibleNotifications.has(origin)) {
      count = this._visibleNotifications.get(origin);
    } else {
      count = 0;
    }
    this._visibleNotifications.set(origin, count + 1);
  },

  notificationForOriginClosed(origin) {
    lazy.console.debug("notificationForOriginClosed()", origin);
    let count;
    if (this._visibleNotifications.has(origin)) {
      count = this._visibleNotifications.get(origin);
    } else {
      lazy.console.debug(
        "notificationForOriginClosed: closing notification that has not been shown?"
      );
      return;
    }
    if (count > 1) {
      this._visibleNotifications.set(origin, count - 1);
    } else {
      this._visibleNotifications.delete(origin);
    }
  },

  reportDeliveryError(messageID, reason) {
    lazy.console.debug("reportDeliveryError()", messageID, reason);
    if (this._state == PUSH_SERVICE_RUNNING && this._service.isConnected()) {
      // Only report errors if we're initialized and connected.
      this._service.reportDeliveryError(messageID, reason);
    }
  },

  _notifyApp(aPushRecord, messageID, message) {
    if (
      !aPushRecord ||
      !aPushRecord.scope ||
      aPushRecord.originAttributes === undefined
    ) {
      lazy.console.error("notifyApp: Invalid record", aPushRecord);
      return Ci.nsIPushErrorReporter.ACK_NOT_DELIVERED;
    }

    lazy.console.debug("notifyApp()", aPushRecord.scope);

    // If permission has been revoked, trash the message.
    if (!aPushRecord.hasPermission()) {
      lazy.console.warn("notifyApp: Missing push permission", aPushRecord);
      return Ci.nsIPushErrorReporter.ACK_NOT_DELIVERED;
    }

    let payload = ArrayBuffer.isView(message)
      ? new Uint8Array(message.buffer)
      : message;

    if (aPushRecord.quotaApplies()) {
      // Don't record telemetry for chrome push messages.
      Services.telemetry.getHistogramById("PUSH_API_NOTIFY").add();
    }

    if (payload) {
      lazy.gPushNotifier.notifyPushWithData(
        aPushRecord.scope,
        aPushRecord.principal,
        messageID,
        payload
      );
    } else {
      lazy.gPushNotifier.notifyPush(
        aPushRecord.scope,
        aPushRecord.principal,
        messageID
      );
    }

    return Ci.nsIPushErrorReporter.ACK_DELIVERED;
  },

  getByKeyID(aKeyID) {
    return this._db.getByKeyID(aKeyID);
  },

  getAllUnexpired() {
    return this._db.getAllUnexpired();
  },

  _sendRequest(action, ...params) {
    if (this._state == PUSH_SERVICE_CONNECTION_DISABLE) {
      return Promise.reject(new Error("Push service disabled"));
    }
    if (this._state == PUSH_SERVICE_ACTIVE_OFFLINE) {
      return Promise.reject(new Error("Push service offline"));
    }
    // Ensure the backend is ready. `getByPageRecord` already checks this, but
    // we need to check again here in case the service was restarted in the
    // meantime.
    return this._checkActivated().then(_ => {
      switch (action) {
        case "register":
          return this._service.register(...params);
        case "unregister":
          return this._service.unregister(...params);
      }
      return Promise.reject(new Error("Unknown request type: " + action));
    });
  },

  /**
   * Called on message from the child process. aPageRecord is an object sent by
   * the push manager, identifying the sending page and other fields.
   */
  _registerWithServer(aPageRecord) {
    lazy.console.debug("registerWithServer()", aPageRecord);

    return this._sendRequest("register", aPageRecord)
      .then(
        record => this._onRegisterSuccess(record),
        err => this._onRegisterError(err)
      )
      .then(
        record => {
          this._deletePendingRequest(aPageRecord);
          lazy.gPushNotifier.notifySubscriptionModified(
            record.scope,
            record.principal
          );
          return record.toSubscription();
        },
        err => {
          this._deletePendingRequest(aPageRecord);
          throw err;
        }
      );
  },

  _sendUnregister(aRecord, aReason) {
    return this._sendRequest("unregister", aRecord, aReason);
  },

  /**
   * Exceptions thrown in _onRegisterSuccess are caught by the promise obtained
   * from _service.request, causing the promise to be rejected instead.
   */
  _onRegisterSuccess(aRecord) {
    lazy.console.debug("_onRegisterSuccess()");

    return this._db.put(aRecord).catch(error => {
      // Unable to save. Destroy the subscription in the background.
      this._backgroundUnregister(
        aRecord,
        Ci.nsIPushErrorReporter.UNSUBSCRIBE_MANUAL
      );
      throw error;
    });
  },

  /**
   * Exceptions thrown in _onRegisterError are caught by the promise obtained
   * from _service.request, causing the promise to be rejected instead.
   */
  _onRegisterError(reply) {
    lazy.console.debug("_onRegisterError()");

    if (!reply.error) {
      lazy.console.warn(
        "onRegisterError: Called without valid error message!",
        reply
      );
      throw new Error("Registration error");
    }
    throw reply.error;
  },

  notificationsCleared() {
    this._visibleNotifications.clear();
  },

  _getByPageRecord(pageRecord) {
    return this._checkActivated().then(_ =>
      this._db.getByIdentifiers(pageRecord)
    );
  },

  register(aPageRecord) {
    lazy.console.debug("register()", aPageRecord);

    let keyPromise;
    if (aPageRecord.appServerKey && aPageRecord.appServerKey.length) {
      let keyView = new Uint8Array(aPageRecord.appServerKey);
      keyPromise = lazy.PushCrypto.validateAppServerKey(keyView).catch(() => {
        // Normalize Web Crypto exceptions. `nsIPushService` will forward the
        // error result to the DOM API implementation in `PushManager.cpp` or
        // `Push.js`, which will convert it to the correct `DOMException`.
        throw errorWithResult(
          "Invalid app server key",
          Cr.NS_ERROR_DOM_PUSH_INVALID_KEY_ERR
        );
      });
    } else {
      keyPromise = Promise.resolve(null);
    }

    return Promise.all([keyPromise, this._getByPageRecord(aPageRecord)]).then(
      ([appServerKey, record]) => {
        aPageRecord.appServerKey = appServerKey;
        if (!record) {
          return this._lookupOrPutPendingRequest(aPageRecord);
        }
        if (!record.matchesAppServerKey(appServerKey)) {
          throw errorWithResult(
            "Mismatched app server key",
            Cr.NS_ERROR_DOM_PUSH_MISMATCHED_KEY_ERR
          );
        }
        if (record.isExpired()) {
          return record
            .quotaChanged()
            .then(isChanged => {
              if (isChanged) {
                // If the user revisited the site, drop the expired push
                // registration and re-register.
                return this.dropRegistrationAndNotifyApp(record.keyID);
              }
              throw new Error("Push subscription expired");
            })
            .then(_ => this._lookupOrPutPendingRequest(aPageRecord));
        }
        return record.toSubscription();
      }
    );
  },

  /*
   * Called only by the PushBroadcastService on the receipt of a new
   * subscription. Don't call this directly. Go through PushBroadcastService.
   */
  async subscribeBroadcast(broadcastId, version) {
    if (this._state != PUSH_SERVICE_RUNNING) {
      // Ignore any request to subscribe before we send a hello.
      // We'll send all the broadcast listeners as part of the hello
      // anyhow.
      return;
    }

    await this._service.sendSubscribeBroadcast(broadcastId, version);
  },

  /**
   * Called on message from the child process.
   *
   * Why is the record being deleted from the local database before the server
   * is told?
   *
   * Unregistration is for the benefit of the app and the AppServer
   * so that the AppServer does not keep pinging a channel the UserAgent isn't
   * watching The important part of the transaction in this case is left to the
   * app, to tell its server of the unregistration.  Even if the request to the
   * PushServer were to fail, it would not affect correctness of the protocol,
   * and the server GC would just clean up the channelID/subscription
   * eventually.  Since the appserver doesn't ping it, no data is lost.
   *
   * If rather we were to unregister at the server and update the database only
   * on success: If the server receives the unregister, and deletes the
   * channelID/subscription, but the response is lost because of network
   * failure, the application is never informed. In addition the application may
   * retry the unregister when it fails due to timeout (websocket) or any other
   * reason at which point the server will say it does not know of this
   * unregistration.  We'll have to make the registration/unregistration phases
   * have retries and attempts to resend messages from the server, and have the
   * client acknowledge. On a server, data is cheap, reliable notification is
   * not.
   */
  unregister(aPageRecord) {
    lazy.console.debug("unregister()", aPageRecord);

    return this._getByPageRecord(aPageRecord).then(record => {
      if (record === null) {
        return false;
      }

      let reason = Ci.nsIPushErrorReporter.UNSUBSCRIBE_MANUAL;
      return Promise.all([
        this._sendUnregister(record, reason),
        this._db.delete(record.keyID).then(rec => {
          if (rec) {
            lazy.gPushNotifier.notifySubscriptionModified(
              rec.scope,
              rec.principal
            );
          }
        }),
      ]).then(([success]) => success);
    });
  },

  clear(info) {
    return this._checkActivated()
      .then(_ => {
        return this._dropRegistrationsIf(
          record =>
            info.domain == "*" ||
            (record.uri &&
              Services.eTLD.hasRootDomain(record.uri.prePath, info.domain))
        );
      })
      .catch(e => {
        lazy.console.warn(
          "clear: Error dropping subscriptions for domain",
          info.domain,
          e
        );
        return Promise.resolve();
      });
  },

  registration(aPageRecord) {
    lazy.console.debug("registration()");

    return this._getByPageRecord(aPageRecord).then(record => {
      if (!record) {
        return null;
      }
      if (record.isExpired()) {
        return record.quotaChanged().then(isChanged => {
          if (isChanged) {
            return this.dropRegistrationAndNotifyApp(record.keyID).then(
              _ => null
            );
          }
          return null;
        });
      }
      return record.toSubscription();
    });
  },

  _dropExpiredRegistrations() {
    lazy.console.debug("dropExpiredRegistrations()");

    return this._db.getAllExpired().then(records => {
      return Promise.all(
        records.map(record =>
          record
            .quotaChanged()
            .then(isChanged => {
              if (isChanged) {
                // If the user revisited the site, drop the expired push
                // registration and notify the associated service worker.
                this.dropRegistrationAndNotifyApp(record.keyID);
              }
            })
            .catch(error => {
              lazy.console.error(
                "dropExpiredRegistrations: Error dropping registration",
                record.keyID,
                error
              );
            })
        )
      );
    });
  },

  _onPermissionChange(subject, data) {
    lazy.console.debug("onPermissionChange()");

    if (data == "cleared") {
      return this._clearPermissions();
    }

    let permission = subject.QueryInterface(Ci.nsIPermission);
    if (permission.type != "desktop-notification") {
      return Promise.resolve();
    }

    return this._updatePermission(permission, data);
  },

  _clearPermissions() {
    lazy.console.debug("clearPermissions()");

    return this._db.clearIf(record => {
      if (!record.quotaApplies()) {
        // Only drop registrations that are subject to quota.
        return false;
      }
      this._backgroundUnregister(
        record,
        Ci.nsIPushErrorReporter.UNSUBSCRIBE_PERMISSION_REVOKED
      );
      return true;
    });
  },

  _updatePermission(permission, type) {
    lazy.console.debug("updatePermission()");

    let isAllow = permission.capability == Ci.nsIPermissionManager.ALLOW_ACTION;
    let isChange = type == "added" || type == "changed";

    if (isAllow && isChange) {
      // Permission set to "allow". Drop all expired registrations for this
      // site, notify the associated service workers, and reset the quota
      // for active registrations.
      return this._forEachPrincipal(permission.principal, (record, cursor) =>
        this._permissionAllowed(record, cursor)
      );
    } else if (isChange || (isAllow && type == "deleted")) {
      // Permission set to "block" or "always ask," or "allow" permission
      // removed. Expire all registrations for this site.
      return this._forEachPrincipal(permission.principal, (record, cursor) =>
        this._permissionDenied(record, cursor)
      );
    }

    return Promise.resolve();
  },

  _forEachPrincipal(principal, callback) {
    return this._db.forEachOrigin(
      principal.URI.prePath,
      ChromeUtils.originAttributesToSuffix(principal.originAttributes),
      callback
    );
  },

  /**
   * The update function called for each registration record if the push
   * permission is revoked. We only expire the record so we can notify the
   * service worker as soon as the permission is reinstated. If we just
   * deleted the record, the worker wouldn't be notified until the next visit
   * to the site.
   *
   * @param {PushRecord} record The record to expire.
   * @param {IDBCursor} cursor The IndexedDB cursor.
   */
  _permissionDenied(record, cursor) {
    lazy.console.debug("permissionDenied()");

    if (!record.quotaApplies() || record.isExpired()) {
      // Ignore already-expired records.
      return;
    }
    // Drop the registration in the background.
    this._backgroundUnregister(
      record,
      Ci.nsIPushErrorReporter.UNSUBSCRIBE_PERMISSION_REVOKED
    );
    record.setQuota(0);
    cursor.update(record);
  },

  /**
   * The update function called for each registration record if the push
   * permission is granted. If the record has expired, it will be dropped;
   * otherwise, its quota will be reset to the default value.
   *
   * @param {PushRecord} record The record to update.
   * @param {IDBCursor} cursor The IndexedDB cursor.
   */
  _permissionAllowed(record, cursor) {
    lazy.console.debug("permissionAllowed()");

    if (!record.quotaApplies()) {
      return;
    }
    if (record.isExpired()) {
      // If the registration has expired, drop and notify the worker
      // unconditionally.
      this._notifySubscriptionChangeObservers(record);
      cursor.delete();
      return;
    }
    record.resetQuota();
    cursor.update(record);
  },

  /**
   * Drops all matching registrations from the database. Notifies the
   * associated service workers if permission is granted, and removes
   * unexpired registrations from the server.
   *
   * @param {Function} predicate A function called for each record.
   * @returns {Promise} Resolves once the registrations have been dropped.
   */
  _dropRegistrationsIf(predicate) {
    return this._db.clearIf(record => {
      if (!predicate(record)) {
        return false;
      }
      if (record.hasPermission()) {
        // "Clear Recent History" and the Forget button remove permissions
        // before clearing registrations, but it's possible for the worker to
        // resubscribe if the "dom.push.testing.ignorePermission" pref is set.
        this._notifySubscriptionChangeObservers(record);
      }
      if (!record.isExpired()) {
        // Only unregister active registrations, since we already told the
        // server about expired ones.
        this._backgroundUnregister(
          record,
          Ci.nsIPushErrorReporter.UNSUBSCRIBE_MANUAL
        );
      }
      return true;
    });
  },
};