aboutsummaryrefslogtreecommitdiffhomepage
path: root/js/message.js
blob: 8def763e9cd137b97034bea655115a41297a448b (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
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

/**
 * @fileoverview Definition of jspb.Message.
 *
 * @author mwr@google.com (Mark Rawling)
 */

goog.provide('jspb.ExtensionFieldBinaryInfo');
goog.provide('jspb.ExtensionFieldInfo');
goog.provide('jspb.Message');

goog.require('goog.array');
goog.require('goog.asserts');
goog.require('goog.crypt.base64');
goog.require('goog.json');
goog.require('jspb.Map');

// Not needed in compilation units that have no protos with xids.
goog.forwardDeclare('xid.String');



/**
 * Stores information for a single extension field.
 *
 * For example, an extension field defined like so:
 *
 *     extend BaseMessage {
 *       optional MyMessage my_field = 123;
 *     }
 *
 * will result in an ExtensionFieldInfo object with these properties:
 *
 *     {
 *       fieldIndex: 123,
 *       fieldName: {my_field_renamed: 0},
 *       ctor: proto.example.MyMessage,
 *       toObjectFn: proto.example.MyMessage.toObject,
 *       isRepeated: 0
 *     }
 *
 * We include `toObjectFn` to allow the JSCompiler to perform dead-code removal
 * on unused toObject() methods.
 *
 * If an extension field is primitive, ctor and toObjectFn will be null.
 * isRepeated should be 0 or 1.
 *
 * binary{Reader,Writer}Fn and (if message type) binaryMessageSerializeFn are
 * always provided. binaryReaderFn and binaryWriterFn are references to the
 * appropriate methods on BinaryReader/BinaryWriter to read/write the value of
 * this extension, and binaryMessageSerializeFn is a reference to the message
 * class's .serializeBinary method, if available.
 *
 * @param {number} fieldNumber
 * @param {Object} fieldName This has the extension field name as a property.
 * @param {?function(new: jspb.Message, Array=)} ctor
 * @param {?function((boolean|undefined),!jspb.Message):!Object} toObjectFn
 * @param {number} isRepeated
 * @constructor
 * @struct
 * @template T
 */
jspb.ExtensionFieldInfo = function(fieldNumber, fieldName, ctor, toObjectFn,
    isRepeated) {
  /** @const */
  this.fieldIndex = fieldNumber;
  /** @const */
  this.fieldName = fieldName;
  /** @const */
  this.ctor = ctor;
  /** @const */
  this.toObjectFn = toObjectFn;
  /** @const */
  this.isRepeated = isRepeated;
};

/**
 * Stores binary-related information for a single extension field.
 * @param {!jspb.ExtensionFieldInfo<T>} fieldInfo
 * @param {!function(number,?)} binaryReaderFn
 * @param {!function(number,?)|function(number,?,?,?,?,?)} binaryWriterFn
 * @param {function(?,?)=} opt_binaryMessageSerializeFn
 * @param {function(?,?)=} opt_binaryMessageDeserializeFn
 * @param {boolean=} opt_isPacked
 * @constructor
 * @struct
 * @template T
 */
jspb.ExtensionFieldBinaryInfo = function(fieldInfo, binaryReaderFn, binaryWriterFn,
    opt_binaryMessageSerializeFn, opt_binaryMessageDeserializeFn, opt_isPacked) {
  /** @const */
  this.fieldInfo = fieldInfo;
  /** @const */
  this.binaryReaderFn = binaryReaderFn;
  /** @const */
  this.binaryWriterFn = binaryWriterFn;
  /** @const */
  this.binaryMessageSerializeFn = opt_binaryMessageSerializeFn;
  /** @const */
  this.binaryMessageDeserializeFn = opt_binaryMessageDeserializeFn;
  /** @const */
  this.isPacked = opt_isPacked;
};

/**
 * @return {boolean} Does this field represent a sub Message?
 */
jspb.ExtensionFieldInfo.prototype.isMessageType = function() {
  return !!this.ctor;
};


/**
 * Base class for all JsPb messages.
 * @constructor
 * @struct
 */
jspb.Message = function() {
};


/**
 * @define {boolean} Whether to generate toObject methods for objects. Turn
 *     this off, if you do not want toObject to be ever used in your project.
 *     When turning off this flag, consider adding a conformance test that bans
 *     calling toObject. Enabling this will disable the JSCompiler's ability to
 *     dead code eliminate fields used in protocol buffers that are never used
 *     in an application.
 */
goog.define('jspb.Message.GENERATE_TO_OBJECT', true);


/**
 * @define {boolean} Whether to generate fromObject methods for objects. Turn
 *     this off, if you do not want fromObject to be ever used in your project.
 *     When turning off this flag, consider adding a conformance test that bans
 *     calling fromObject. Enabling this might disable the JSCompiler's ability
 *     to dead code eliminate fields used in protocol buffers that are never
 *     used in an application.
 *     NOTE: By default no protos actually have a fromObject method. You need to
 *     add the jspb.generate_from_object options to the proto definition to
 *     activate the feature.
 *     By default this is enabled for test code only.
 */
goog.define('jspb.Message.GENERATE_FROM_OBJECT', !goog.DISALLOW_TEST_ONLY_CODE);


/**
 * @define {boolean} Turning on this flag does NOT change the behavior of JSPB
 *     and only affects private internal state. It may, however, break some
 *     tests that use naive deeply-equals algorithms, because using a proto
 *     mutates its internal state.
 *     Projects are advised to turn this flag always on.
 */
goog.define('jspb.Message.MINIMIZE_MEMORY_ALLOCATIONS', COMPILED);
// TODO(b/19419436) Turn this on by default.


/**
 * Does this browser support Uint8Aray typed arrays?
 * @type {boolean}
 * @private
 */
jspb.Message.SUPPORTS_UINT8ARRAY_ = (typeof Uint8Array == 'function');


/**
 * The internal data array.
 * @type {!Array}
 * @protected
 */
jspb.Message.prototype.array;


/**
 * Wrappers are the constructed instances of message-type fields. They are built
 * on demand from the raw array data. Includes message fields, repeated message
 * fields and extension message fields. Indexed by field number.
 * @type {Object}
 * @private
 */
jspb.Message.prototype.wrappers_;


/**
 * The object that contains extension fields, if any. This is an object that
 * maps from a proto field number to the field's value.
 * @type {Object}
 * @private
 */
jspb.Message.prototype.extensionObject_;


/**
 * Non-extension fields with a field number at or above the pivot are
 * stored in the extension object (in addition to all extension fields).
 * @type {number}
 * @private
 */
jspb.Message.prototype.pivot_;


/**
 * The JsPb message_id of this proto.
 * @type {string|undefined} the message id or undefined if this message
 *     has no id.
 * @private
 */
jspb.Message.prototype.messageId_;


/**
 * Repeated float or double fields which have been converted to include only
 * numbers and not strings holding "NaN", "Infinity" and "-Infinity".
 * @private {!Object<number,boolean>|undefined}
 */
jspb.Message.prototype.convertedFloatingPointFields_;


/**
 * The xid of this proto type (The same for all instances of a proto). Provides
 * a way to identify a proto by stable obfuscated name.
 * @see {xid}.
 * Available if {@link jspb.generate_xid} is added as a Message option to
 * a protocol buffer.
 * @const {!xid.String|undefined} The xid or undefined if message is
 *     annotated to generate the xid.
 */
jspb.Message.prototype.messageXid;



/**
 * Returns the JsPb message_id of this proto.
 * @return {string|undefined} the message id or undefined if this message
 *     has no id.
 */
jspb.Message.prototype.getJsPbMessageId = function() {
  return this.messageId_;
};


/**
 * An offset applied to lookups into this.array to account for the presence or
 * absence of a messageId at position 0. For response messages, this will be 0.
 * Otherwise, it will be -1 so that the first array position is not wasted.
 * @type {number}
 * @private
 */
jspb.Message.prototype.arrayIndexOffset_;


/**
 * Returns the index into msg.array at which the proto field with tag number
 * fieldNumber will be located.
 * @param {!jspb.Message} msg Message for which we're calculating an index.
 * @param {number} fieldNumber The field number.
 * @return {number} The index.
 * @private
 */
jspb.Message.getIndex_ = function(msg, fieldNumber) {
  return fieldNumber + msg.arrayIndexOffset_;
};


/**
 * Initializes a JsPb Message.
 * @param {!jspb.Message} msg The JsPb proto to modify.
 * @param {Array|undefined} data An initial data array.
 * @param {string|number} messageId For response messages, the message id or ''
 *     if no message id is specified. For non-response messages, 0.
 * @param {number} suggestedPivot The field number at which to start putting
 *     fields into the extension object. This is only used if data does not
 *     contain an extension object already. -1 if no extension object is
 *     required for this message type.
 * @param {Array<number>} repeatedFields The message's repeated fields.
 * @param {Array<!Array<number>>=} opt_oneofFields The fields belonging to
 *     each of the message's oneof unions.
 * @protected
 */
jspb.Message.initialize = function(
    msg, data, messageId, suggestedPivot, repeatedFields, opt_oneofFields) {
  msg.wrappers_ = jspb.Message.MINIMIZE_MEMORY_ALLOCATIONS ? null : {};
  if (!data) {
    data = messageId ? [messageId] : [];
  }
  msg.messageId_ = messageId ? String(messageId) : undefined;
  // If the messageId is 0, this message is not a response message, so we shift
  // array indices down by 1 so as not to waste the first position in the array,
  // which would otherwise go unused.
  msg.arrayIndexOffset_ = messageId === 0 ? -1 : 0;
  msg.array = data;
  jspb.Message.materializeExtensionObject_(msg, suggestedPivot);
  msg.convertedFloatingPointFields_ = {};

  if (repeatedFields) {
    for (var i = 0; i < repeatedFields.length; i++) {
      var fieldNumber = repeatedFields[i];
      if (fieldNumber < msg.pivot_) {
        var index = jspb.Message.getIndex_(msg, fieldNumber);
        msg.array[index] = msg.array[index] ||
            (jspb.Message.MINIMIZE_MEMORY_ALLOCATIONS ?
                jspb.Message.EMPTY_LIST_SENTINEL_ :
                []);
      } else {
        msg.extensionObject_[fieldNumber] =
            msg.extensionObject_[fieldNumber] ||
            (jspb.Message.MINIMIZE_MEMORY_ALLOCATIONS ?
                jspb.Message.EMPTY_LIST_SENTINEL_ :
                []);
      }
    }
  }

  if (opt_oneofFields && opt_oneofFields.length) {
    // Compute the oneof case for each union. This ensures only one value is
    // set in the union.
    goog.array.forEach(
        opt_oneofFields, goog.partial(jspb.Message.computeOneofCase, msg));
  }
};


/**
 * Used to mark empty repeated fields. Serializes to null when serialized
 * to JSON.
 * When reading a repeated field readers must check the return value against
 * this value and return and replace it with a new empty array if it is
 * present.
 * @private @const {!Object}
 */
jspb.Message.EMPTY_LIST_SENTINEL_ = goog.DEBUG && Object.freeze ?
    Object.freeze([]) :
    [];


/**
 * Ensures that the array contains an extension object if necessary.
 * If the array contains an extension object in its last position, then the
 * object is kept in place and its position is used as the pivot.  If not, then
 * create an extension object using suggestedPivot.  If suggestedPivot is -1,
 * we don't have an extension object at all, in which case all fields are stored
 * in the array.
 * @param {!jspb.Message} msg The JsPb proto to modify.
 * @param {number} suggestedPivot See description for initialize().
 * @private
 */
jspb.Message.materializeExtensionObject_ = function(msg, suggestedPivot) {
  if (msg.array.length) {
    var foundIndex = msg.array.length - 1;
    var obj = msg.array[foundIndex];
    // Normal fields are never objects, so we can be sure that if we find an
    // object here, then it's the extension object. However, we must ensure that
    // the object is not an array, since arrays are valid field values.
    // NOTE(lukestebbing): We avoid looking at .length to avoid a JIT bug
    // in Safari on iOS 8. See the description of CL/86511464 for details.
    if (obj && typeof obj == 'object' && !goog.isArray(obj) &&
       !(jspb.Message.SUPPORTS_UINT8ARRAY_ && obj instanceof Uint8Array)) {
      msg.pivot_ = foundIndex - msg.arrayIndexOffset_;
      msg.extensionObject_ = obj;
      return;
    }
  }
  // This complexity exists because we keep all extension fields in the
  // extensionObject_ regardless of proto field number. Changing this would
  // simplify the code here, but it would require changing the serialization
  // format from the server, which is not backwards compatible.
  // TODO(jshneier): Should we just treat extension fields the same as
  // non-extension fields, and select whether they appear in the object or in
  // the array purely based on tag number? This would allow simplifying all the
  // get/setExtension logic, but it would require the breaking change described
  // above.
  if (suggestedPivot > -1) {
    msg.pivot_ = suggestedPivot;
    var pivotIndex = jspb.Message.getIndex_(msg, suggestedPivot);
    if (!jspb.Message.MINIMIZE_MEMORY_ALLOCATIONS) {
      msg.extensionObject_ = msg.array[pivotIndex] = {};
    } else {
      // Initialize to null to avoid changing the shape of the proto when it
      // gets eventually set.
      msg.extensionObject_ = null;
    }
  } else {
    msg.pivot_ = Number.MAX_VALUE;
  }
};


/**
 * Creates an empty extensionObject_ if non exists.
 * @param {!jspb.Message} msg The JsPb proto to modify.
 * @private
 */
jspb.Message.maybeInitEmptyExtensionObject_ = function(msg) {
  var pivotIndex = jspb.Message.getIndex_(msg, msg.pivot_);
  if (!msg.array[pivotIndex]) {
    msg.extensionObject_ = msg.array[pivotIndex] = {};
  }
};


/**
 * Converts a JsPb repeated message field into an object list.
 * @param {!Array<T>} field The repeated message field to be
 *     converted.
 * @param {?function(boolean=): Object|
 *     function((boolean|undefined),T): Object} toObjectFn The toObject
 *     function for this field.  We need to pass this for effective dead code
 *     removal.
 * @param {boolean=} opt_includeInstance Whether to include the JSPB instance
 *     for transitional soy proto support: http://goto/soy-param-migration
 * @return {!Array<Object>} An array of converted message objects.
 * @template T
 */
jspb.Message.toObjectList = function(field, toObjectFn, opt_includeInstance) {
  // Not using goog.array.map in the generated code to keep it small.
  // And not using it here to avoid a function call.
  var result = [];
  for (var i = 0; i < field.length; i++) {
    result[i] = toObjectFn.call(field[i], opt_includeInstance,
      /** @type {!jspb.Message} */ (field[i]));
  }
  return result;
};


/**
 * Adds a proto's extension data to a Soy rendering object.
 * @param {!jspb.Message} proto The proto whose extensions to convert.
 * @param {!Object} obj The Soy object to add converted extension data to.
 * @param {!Object} extensions The proto class' registered extensions.
 * @param {function(this:?, jspb.ExtensionFieldInfo) : *} getExtensionFn
 *     The proto class' getExtension function. Passed for effective dead code
 *     removal.
 * @param {boolean=} opt_includeInstance Whether to include the JSPB instance
 *     for transitional soy proto support: http://goto/soy-param-migration
 */
jspb.Message.toObjectExtension = function(proto, obj, extensions,
    getExtensionFn, opt_includeInstance) {
  for (var fieldNumber in extensions) {
    var fieldInfo = extensions[fieldNumber];
    var value = getExtensionFn.call(proto, fieldInfo);
    if (value) {
      for (var name in fieldInfo.fieldName) {
        if (fieldInfo.fieldName.hasOwnProperty(name)) {
          break; // the compiled field name
        }
      }
      if (!fieldInfo.toObjectFn) {
        obj[name] = value;
      } else {
        if (fieldInfo.isRepeated) {
          obj[name] = jspb.Message.toObjectList(
              /** @type {!Array<jspb.Message>} */ (value),
              fieldInfo.toObjectFn, opt_includeInstance);
        } else {
          obj[name] = fieldInfo.toObjectFn(opt_includeInstance, value);
        }
      }
    }
  }
};


/**
 * Writes a proto's extension data to a binary-format output stream.
 * @param {!jspb.Message} proto The proto whose extensions to convert.
 * @param {*} writer The binary-format writer to write to.
 * @param {!Object} extensions The proto class' registered extensions.
 * @param {function(jspb.ExtensionFieldInfo) : *} getExtensionFn The proto
 *     class' getExtension function. Passed for effective dead code removal.
 */
jspb.Message.serializeBinaryExtensions = function(proto, writer, extensions,
    getExtensionFn) {
  for (var fieldNumber in extensions) {
    var binaryFieldInfo = extensions[fieldNumber];
    var fieldInfo = binaryFieldInfo.fieldInfo;

    // The old codegen doesn't add the extra fields to ExtensionFieldInfo, so we
    // need to gracefully error-out here rather than produce a null dereference
    // below.
    if (!binaryFieldInfo.binaryWriterFn) {
      throw new Error('Message extension present that was generated ' +
                      'without binary serialization support');
    }
    var value = getExtensionFn.call(proto, fieldInfo);
    if (value) {
      if (fieldInfo.isMessageType()) {
        // If the message type of the extension was generated without binary
        // support, there may not be a binary message serializer function, and
        // we can't know when we codegen the extending message that the extended
        // message may require binary support, so we can *only* catch this error
        // here, at runtime (and this decoupled codegen is the whole point of
        // extensions!).
        if (binaryFieldInfo.binaryMessageSerializeFn) {
          binaryFieldInfo.binaryWriterFn.call(writer, fieldInfo.fieldIndex,
              value, binaryFieldInfo.binaryMessageSerializeFn);
        } else {
          throw new Error('Message extension present holding submessage ' +
                          'without binary support enabled, and message is ' +
                          'being serialized to binary format');
        }
      } else {
        binaryFieldInfo.binaryWriterFn.call(
            writer, fieldInfo.fieldIndex, value);
      }
    }
  }
};


/**
 * Reads an extension field from the given reader and, if a valid extension,
 * sets the extension value.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {{skipField:function(),getFieldNumber:function():number}} reader
 * @param {!Object} extensions The extensions object.
 * @param {function(jspb.ExtensionFieldInfo)} getExtensionFn
 * @param {function(jspb.ExtensionFieldInfo, ?)} setExtensionFn
 */
jspb.Message.readBinaryExtension = function(msg, reader, extensions,
    getExtensionFn, setExtensionFn) {
  var binaryFieldInfo = extensions[reader.getFieldNumber()];
  var fieldInfo = binaryFieldInfo.fieldInfo;
  if (!binaryFieldInfo) {
    reader.skipField();
    return;
  }
  if (!binaryFieldInfo.binaryReaderFn) {
    throw new Error('Deserializing extension whose generated code does not ' +
                    'support binary format');
  }

  var value;
  if (fieldInfo.isMessageType()) {
    value = new fieldInfo.ctor();
    binaryFieldInfo.binaryReaderFn.call(
        reader, value, binaryFieldInfo.binaryMessageDeserializeFn);
  } else {
    // All other types.
    value = binaryFieldInfo.binaryReaderFn.call(reader);
  }

  if (fieldInfo.isRepeated && !binaryFieldInfo.isPacked) {
    var currentList = getExtensionFn.call(msg, fieldInfo);
    if (!currentList) {
      setExtensionFn.call(msg, fieldInfo, [value]);
    } else {
      currentList.push(value);
    }
  } else {
    setExtensionFn.call(msg, fieldInfo, value);
  }
};


/**
 * Gets the value of a non-extension field.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @return {string|number|boolean|Uint8Array|Array|null|undefined}
 * The field's value.
 * @protected
 */
jspb.Message.getField = function(msg, fieldNumber) {
  if (fieldNumber < msg.pivot_) {
    var index = jspb.Message.getIndex_(msg, fieldNumber);
    var val = msg.array[index];
    if (val === jspb.Message.EMPTY_LIST_SENTINEL_) {
      return msg.array[index] = [];
    }
    return val;
  } else {
    var val = msg.extensionObject_[fieldNumber];
    if (val === jspb.Message.EMPTY_LIST_SENTINEL_) {
      return msg.extensionObject_[fieldNumber] = [];
    }
    return val;
  }
};


/**
 * Gets the value of an optional float or double field.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @return {?number|undefined} The field's value.
 * @protected
 */
jspb.Message.getOptionalFloatingPointField = function(msg, fieldNumber) {
  var value = jspb.Message.getField(msg, fieldNumber);
  // Converts "NaN", "Infinity" and "-Infinity" to their corresponding numbers.
  return value == null ? value : +value;
};


/**
 * Gets the value of a repeated float or double field.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @return {!Array<number>} The field's value.
 * @protected
 */
jspb.Message.getRepeatedFloatingPointField = function(msg, fieldNumber) {
  var values = jspb.Message.getField(msg, fieldNumber);
  if (!msg.convertedFloatingPointFields_) {
    msg.convertedFloatingPointFields_ = {};
  }
  if (!msg.convertedFloatingPointFields_[fieldNumber]) {
    for (var i = 0; i < values.length; i++) {
      // Converts "NaN", "Infinity" and "-Infinity" to their corresponding
      // numbers.
      values[i] = +values[i];
    }
    msg.convertedFloatingPointFields_[fieldNumber] = true;
  }
  return /** @type {!Array<number>} */ (values);
};


/**
 * Coerce a 'bytes' field to a base 64 string.
 * @param {string|Uint8Array|null} value
 * @return {?string} The field's coerced value.
 */
jspb.Message.bytesAsB64 = function(value) {
  if (value == null || goog.isString(value)) {
    return value;
  }
  if (jspb.Message.SUPPORTS_UINT8ARRAY_ && value instanceof Uint8Array) {
    return goog.crypt.base64.encodeByteArray(value);
  }
  goog.asserts.fail('Cannot coerce to b64 string: ' + goog.typeOf(value));
  return null;
};


/**
 * Coerce a 'bytes' field to a Uint8Array byte buffer.
 * Note that Uint8Array is not supported on IE versions before 10 nor on Opera
 * Mini. @see http://caniuse.com/Uint8Array
 * @param {string|Uint8Array|null} value
 * @return {?Uint8Array} The field's coerced value.
 */
jspb.Message.bytesAsU8 = function(value) {
  if (value == null || value instanceof Uint8Array) {
    return value;
  }
  if (goog.isString(value)) {
    return goog.crypt.base64.decodeStringToUint8Array(value);
  }
  goog.asserts.fail('Cannot coerce to Uint8Array: ' + goog.typeOf(value));
  return null;
};


/**
 * Coerce a repeated 'bytes' field to an array of base 64 strings.
 * Note: the returned array should be treated as immutable.
 * @param {!Array<string>|!Array<!Uint8Array>} value
 * @return {!Array<string?>} The field's coerced value.
 */
jspb.Message.bytesListAsB64 = function(value) {
  jspb.Message.assertConsistentTypes_(value);
  if (!value.length || goog.isString(value[0])) {
    return /** @type {!Array<string>} */ (value);
  }
  return goog.array.map(value, jspb.Message.bytesAsB64);
};


/**
 * Coerce a repeated 'bytes' field to an array of Uint8Array byte buffers.
 * Note: the returned array should be treated as immutable.
 * Note that Uint8Array is not supported on IE versions before 10 nor on Opera
 * Mini. @see http://caniuse.com/Uint8Array
 * @param {!Array<string>|!Array<!Uint8Array>} value
 * @return {!Array<Uint8Array?>} The field's coerced value.
 */
jspb.Message.bytesListAsU8 = function(value) {
  jspb.Message.assertConsistentTypes_(value);
  if (!value.length || value[0] instanceof Uint8Array) {
    return /** @type {!Array<!Uint8Array>} */ (value);
  }
  return goog.array.map(value, jspb.Message.bytesAsU8);
};


/**
 * Asserts that all elements of an array are of the same type.
 * @param {Array?} array The array to test.
 * @private
 */
jspb.Message.assertConsistentTypes_ = function(array) {
  if (goog.DEBUG && array && array.length > 1) {
    var expected = goog.typeOf(array[0]);
    goog.array.forEach(array, function(e) {
      if (goog.typeOf(e) != expected) {
        goog.asserts.fail('Inconsistent type in JSPB repeated field array. ' +
            'Got ' + goog.typeOf(e) + ' expected ' + expected);
      }
    });
  }
};


/**
 * Gets the value of a non-extension primitive field, with proto3 (non-nullable
 * primitives) semantics. Returns `defaultValue` if the field is not otherwise
 * set.
 * @template T
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @param {T} defaultValue The default value.
 * @return {T} The field's value.
 * @protected
 */
jspb.Message.getFieldWithDefault = function(msg, fieldNumber, defaultValue) {
  var value = jspb.Message.getField(msg, fieldNumber);
  if (value == null) {
    return defaultValue;
  } else {
    return value;
  }
};


/**
 * Alias for getFieldWithDefault used by older generated code.
 * @template T
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @param {T} defaultValue The default value.
 * @return {T} The field's value.
 * @protected
 */
jspb.Message.getFieldProto3 = jspb.Message.getFieldWithDefault;


/**
 * Gets the value of a map field, lazily creating the map container if
 * necessary.
 *
 * This should only be called from generated code, because it requires knowledge
 * of serialization/parsing callbacks (which are required by the map at
 * construction time, and the map may be constructed here).
 *
 * @template K, V
 * @param {!jspb.Message} msg
 * @param {number} fieldNumber
 * @param {boolean|undefined} noLazyCreate
 * @param {?=} opt_valueCtor
 * @return {!jspb.Map<K, V>|undefined}
 * @protected
 */
jspb.Message.getMapField = function(msg, fieldNumber, noLazyCreate,
    opt_valueCtor) {
  if (!msg.wrappers_) {
    msg.wrappers_ = {};
  }
  // If we already have a map in the map wrappers, return that.
  if (fieldNumber in msg.wrappers_) {
    return msg.wrappers_[fieldNumber];
  } else if (noLazyCreate) {
    return undefined;
  } else {
    // Wrap the underlying elements array with a Map.
    var arr = jspb.Message.getField(msg, fieldNumber);
    if (!arr) {
      arr = [];
      jspb.Message.setField(msg, fieldNumber, arr);
    }
    return msg.wrappers_[fieldNumber] =
        new jspb.Map(
            /** @type {!Array<!Array<!Object>>} */ (arr), opt_valueCtor);
  }
};


/**
 * Sets the value of a non-extension field.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @param {string|number|boolean|Uint8Array|Array|undefined} value New value
 * @protected
 */
jspb.Message.setField = function(msg, fieldNumber, value) {
  if (fieldNumber < msg.pivot_) {
    msg.array[jspb.Message.getIndex_(msg, fieldNumber)] = value;
  } else {
    msg.extensionObject_[fieldNumber] = value;
  }
};


/**
 * Adds a value to a repeated, primitive field.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @param {string|number|boolean|!Uint8Array} value New value
 * @param {number=} opt_index Index where to put new value.
 * @protected
 */
jspb.Message.addToRepeatedField = function(msg, fieldNumber, value, opt_index) {
  var arr = jspb.Message.getField(msg, fieldNumber);
  if (opt_index != undefined) {
    arr.splice(opt_index, 0, value);
  } else {
    arr.push(value);
  }
};


/**
 * Sets the value of a field in a oneof union and clears all other fields in
 * the union.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @param {!Array<number>} oneof The fields belonging to the union.
 * @param {string|number|boolean|Uint8Array|Array|undefined} value New value
 * @protected
 */
jspb.Message.setOneofField = function(msg, fieldNumber, oneof, value) {
  var currentCase = jspb.Message.computeOneofCase(msg, oneof);
  if (currentCase && currentCase !== fieldNumber && value !== undefined) {
    if (msg.wrappers_ && currentCase in msg.wrappers_) {
      msg.wrappers_[currentCase] = undefined;
    }
    jspb.Message.setField(msg, currentCase, undefined);
  }
  jspb.Message.setField(msg, fieldNumber, value);
};


/**
 * Computes the selection in a oneof group for the given message, ensuring
 * only one field is set in the process.
 *
 * According to the protobuf language guide (
 * https://developers.google.com/protocol-buffers/docs/proto#oneof), "if the
 * parser encounters multiple members of the same oneof on the wire, only the
 * last member seen is used in the parsed message." Since JSPB serializes
 * messages to a JSON array, the "last member seen" will always be the field
 * with the greatest field number (directly corresponding to the greatest
 * array index).
 *
 * @param {!jspb.Message} msg A jspb proto.
 * @param {!Array<number>} oneof The field numbers belonging to the union.
 * @return {number} The field number currently set in the union, or 0 if none.
 * @protected
 */
jspb.Message.computeOneofCase = function(msg, oneof) {
  var oneofField;
  var oneofValue;

  goog.array.forEach(oneof, function(fieldNumber) {
    var value = jspb.Message.getField(msg, fieldNumber);
    if (goog.isDefAndNotNull(value)) {
      oneofField = fieldNumber;
      oneofValue = value;
      jspb.Message.setField(msg, fieldNumber, undefined);
    }
  });

  if (oneofField) {
    // NB: We know the value is unique, so we can call jspb.Message.setField
    // directly instead of jpsb.Message.setOneofField. Also, setOneofField
    // calls this function.
    jspb.Message.setField(msg, oneofField, oneofValue);
    return oneofField;
  }

  return 0;
};


/**
 * Gets and wraps a proto field on access.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {function(new:jspb.Message, Array)} ctor Constructor for the field.
 * @param {number} fieldNumber The field number.
 * @param {number=} opt_required True (1) if this is a required field.
 * @return {jspb.Message} The field as a jspb proto.
 * @protected
 */
jspb.Message.getWrapperField = function(msg, ctor, fieldNumber, opt_required) {
  // TODO(mwr): Consider copying data and/or arrays.
  if (!msg.wrappers_) {
    msg.wrappers_ = {};
  }
  if (!msg.wrappers_[fieldNumber]) {
    var data = /** @type {Array} */ (jspb.Message.getField(msg, fieldNumber));
    if (opt_required || data) {
      // TODO(mwr): Remove existence test for always valid default protos.
      msg.wrappers_[fieldNumber] = new ctor(data);
    }
  }
  return /** @type {jspb.Message} */ (msg.wrappers_[fieldNumber]);
};


/**
 * Gets and wraps a repeated proto field on access.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {function(new:jspb.Message, Array)} ctor Constructor for the field.
 * @param {number} fieldNumber The field number.
 * @return {Array<!jspb.Message>} The repeated field as an array of protos.
 * @protected
 */
jspb.Message.getRepeatedWrapperField = function(msg, ctor, fieldNumber) {
  jspb.Message.wrapRepeatedField_(msg, ctor, fieldNumber);
  var val = msg.wrappers_[fieldNumber];
  if (val == jspb.Message.EMPTY_LIST_SENTINEL_) {
    val = msg.wrappers_[fieldNumber] = [];
  }
  return /** @type {!Array<!jspb.Message>} */ (val);
};


/**
 * Wraps underlying array into proto message representation if it wasn't done
 * before.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {function(new:jspb.Message, ?Array)} ctor Constructor for the field.
 * @param {number} fieldNumber The field number.
 * @private
 */
jspb.Message.wrapRepeatedField_ = function(msg, ctor, fieldNumber) {
  if (!msg.wrappers_) {
    msg.wrappers_ = {};
  }
  if (!msg.wrappers_[fieldNumber]) {
    var data = jspb.Message.getField(msg, fieldNumber);
    for (var wrappers = [], i = 0; i < data.length; i++) {
      wrappers[i] = new ctor(data[i]);
    }
    msg.wrappers_[fieldNumber] = wrappers;
  }
};


/**
 * Sets a proto field and syncs it to the backing array.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @param {jspb.Message|undefined} value A new value for this proto field.
 * @protected
 */
jspb.Message.setWrapperField = function(msg, fieldNumber, value) {
  if (!msg.wrappers_) {
    msg.wrappers_ = {};
  }
  var data = value ? value.toArray() : value;
  msg.wrappers_[fieldNumber] = value;
  jspb.Message.setField(msg, fieldNumber, data);
};


/**
 * Sets a proto field in a oneof union and syncs it to the backing array.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @param {!Array<number>} oneof The fields belonging to the union.
 * @param {jspb.Message|undefined} value A new value for this proto field.
 * @protected
 */
jspb.Message.setOneofWrapperField = function(msg, fieldNumber, oneof, value) {
  if (!msg.wrappers_) {
    msg.wrappers_ = {};
  }
  var data = value ? value.toArray() : value;
  msg.wrappers_[fieldNumber] = value;
  jspb.Message.setOneofField(msg, fieldNumber, oneof, data);
};


/**
 * Sets a repeated proto field and syncs it to the backing array.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @param {Array<!jspb.Message>|undefined} value An array of protos.
 * @protected
 */
jspb.Message.setRepeatedWrapperField = function(msg, fieldNumber, value) {
  if (!msg.wrappers_) {
    msg.wrappers_ = {};
  }
  value = value || [];
  for (var data = [], i = 0; i < value.length; i++) {
    data[i] = value[i].toArray();
  }
  msg.wrappers_[fieldNumber] = value;
  jspb.Message.setField(msg, fieldNumber, data);
};


/**
 * Add a message to a repeated proto field.
 * @param {!jspb.Message} msg A jspb proto.
 * @param {number} fieldNumber The field number.
 * @param {T_CHILD|undefined} value Proto that will be added to the
 *     repeated field.
 * @param {function(new:T_CHILD, ?Array=)} ctor The constructor of the
 *     message type.
 * @param {number|undefined} index Index at which to insert the value.
 * @return {T_CHILD_NOT_UNDEFINED} proto that was inserted to the repeated field
 * @template MessageType
 * Use go/closure-ttl to declare a non-undefined version of T_CHILD. Replace the
 * undefined in blah|undefined with none. This is necessary because the compiler
 * will infer T_CHILD to be |undefined.
 * @template T_CHILD
 * @template T_CHILD_NOT_UNDEFINED :=
 *     cond(isUnknown(T_CHILD), unknown(),
 *       mapunion(T_CHILD, (X) =>
 *         cond(eq(X, 'undefined'), none(), X)))
 * =:
 * @protected
 */
jspb.Message.addToRepeatedWrapperField = function(
    msg, fieldNumber, value, ctor, index) {
  jspb.Message.wrapRepeatedField_(msg, ctor, fieldNumber);
  var wrapperArray = msg.wrappers_[fieldNumber];
  if (!wrapperArray) {
    wrapperArray = msg.wrappers_[fieldNumber] = [];
  }
  var insertedValue = value ? value : new ctor();
  var array = jspb.Message.getField(msg, fieldNumber);
  if (index != undefined) {
    wrapperArray.splice(index, 0, insertedValue);
    array.splice(index, 0, insertedValue.toArray());
  } else {
    wrapperArray.push(insertedValue);
    array.push(insertedValue.toArray());
  }
  return insertedValue;
};


/**
 * Converts a JsPb repeated message field into a map. The map will contain
 * protos unless an optional toObject function is given, in which case it will
 * contain objects suitable for Soy rendering.
 * @param {!Array<T>} field The repeated message field to be
 *     converted.
 * @param {function() : string?} mapKeyGetterFn The function to get the key of
 *     the map.
 * @param {?function(boolean=): Object|
 *     function((boolean|undefined),T): Object} opt_toObjectFn The
 *     toObject function for this field. We need to pass this for effective
 *     dead code removal.
 * @param {boolean=} opt_includeInstance Whether to include the JSPB instance
 *     for transitional soy proto support: http://goto/soy-param-migration
 * @return {!Object.<string, Object>} A map of proto or Soy objects.
 * @template T
 */
jspb.Message.toMap = function(
    field, mapKeyGetterFn, opt_toObjectFn, opt_includeInstance) {
  var result = {};
  for (var i = 0; i < field.length; i++) {
    result[mapKeyGetterFn.call(field[i])] = opt_toObjectFn ?
        opt_toObjectFn.call(field[i], opt_includeInstance,
            /** @type {!jspb.Message} */ (field[i])) : field[i];
  }
  return result;
};


/**
 * Syncs all map fields' contents back to their underlying arrays.
 * @private
 */
jspb.Message.prototype.syncMapFields_ = function() {
  // This iterates over submessage, map, and repeated fields, which is intended.
  // Submessages can contain maps which also need to be synced.
  //
  // There is a lot of opportunity for optimization here.  For example we could
  // statically determine that some messages have no submessages with maps and
  // optimize this method away for those just by generating one extra static
  // boolean per message type.
  if (this.wrappers_) {
    for (var fieldNumber in this.wrappers_) {
      var val = this.wrappers_[fieldNumber];
      if (goog.isArray(val)) {
        for (var i = 0; i < val.length; i++) {
          if (val[i]) {
            val[i].toArray();
          }
        }
      } else {
        // Works for submessages and maps.
        if (val) {
          val.toArray();
        }
      }
    }
  }
};


/**
 * Returns the internal array of this proto.
 * <p>Note: If you use this array to construct a second proto, the content
 * would then be partially shared between the two protos.
 * @return {!Array} The proto represented as an array.
 */
jspb.Message.prototype.toArray = function() {
  this.syncMapFields_();
  return this.array;
};




/**
 * Creates a string representation of the internal data array of this proto.
 * <p>NOTE: This string is *not* suitable for use in server requests.
 * @return {string} A string representation of this proto.
 * @override
 */
jspb.Message.prototype.toString = function() {
  this.syncMapFields_();
  return this.array.toString();
};


/**
 * Gets the value of the extension field from the extended object.
 * @param {jspb.ExtensionFieldInfo.<T>} fieldInfo Specifies the field to get.
 * @return {T} The value of the field.
 * @template T
 */
jspb.Message.prototype.getExtension = function(fieldInfo) {
  if (!this.extensionObject_) {
    return undefined;
  }
  if (!this.wrappers_) {
    this.wrappers_ = {};
  }
  var fieldNumber = fieldInfo.fieldIndex;
  if (fieldInfo.isRepeated) {
    if (fieldInfo.isMessageType()) {
      if (!this.wrappers_[fieldNumber]) {
        this.wrappers_[fieldNumber] =
            goog.array.map(this.extensionObject_[fieldNumber] || [],
                function(arr) {
                  return new fieldInfo.ctor(arr);
                });
      }
      return this.wrappers_[fieldNumber];
    } else {
      return this.extensionObject_[fieldNumber];
    }
  } else {
    if (fieldInfo.isMessageType()) {
      if (!this.wrappers_[fieldNumber] && this.extensionObject_[fieldNumber]) {
        this.wrappers_[fieldNumber] = new fieldInfo.ctor(
            /** @type {Array|undefined} */ (
                this.extensionObject_[fieldNumber]));
      }
      return this.wrappers_[fieldNumber];
    } else {
      return this.extensionObject_[fieldNumber];
    }
  }
};


/**
 * Sets the value of the extension field in the extended object.
 * @param {jspb.ExtensionFieldInfo} fieldInfo Specifies the field to set.
 * @param {jspb.Message|string|Uint8Array|number|boolean|Array?} value The value
 *     to set.
 * @return {THIS} For chaining
 * @this {THIS}
 * @template THIS
 */
jspb.Message.prototype.setExtension = function(fieldInfo, value) {
  // Cast self, since the inferred THIS is unknown inside the function body.
  // https://github.com/google/closure-compiler/issues/1411#issuecomment-232442220
  var self = /** @type {!jspb.Message} */ (this);
  if (!self.wrappers_) {
    self.wrappers_ = {};
  }
  jspb.Message.maybeInitEmptyExtensionObject_(self);
  var fieldNumber = fieldInfo.fieldIndex;
  if (fieldInfo.isRepeated) {
    value = value || [];
    if (fieldInfo.isMessageType()) {
      self.wrappers_[fieldNumber] = value;
      self.extensionObject_[fieldNumber] = goog.array.map(
          /** @type {Array<jspb.Message>} */ (value), function(msg) {
        return msg.toArray();
      });
    } else {
      self.extensionObject_[fieldNumber] = value;
    }
  } else {
    if (fieldInfo.isMessageType()) {
      self.wrappers_[fieldNumber] = value;
      self.extensionObject_[fieldNumber] = value ? value.toArray() : value;
    } else {
      self.extensionObject_[fieldNumber] = value;
    }
  }
  return self;
};


/**
 * Creates a difference object between two messages.
 *
 * The result will contain the top-level fields of m2 that differ from those of
 * m1 at any level of nesting. No data is cloned, the result object will
 * share its top-level elements with m2 (but not with m1).
 *
 * Note that repeated fields should not have null/undefined elements, but if
 * they do, this operation will treat repeated fields of different length as
 * the same if the only difference between them is due to trailing
 * null/undefined values.
 *
 * @param {!jspb.Message} m1 The first message object.
 * @param {!jspb.Message} m2 The second message object.
 * @return {!jspb.Message} The difference returned as a proto message.
 *     Note that the returned message may be missing required fields. This is
 *     currently tolerated in Js, but would cause an error if you tried to
 *     send such a proto to the server. You can access the raw difference
 *     array with result.toArray().
 * @throws {Error} If the messages are responses with different types.
 */
jspb.Message.difference = function(m1, m2) {
  if (!(m1 instanceof m2.constructor)) {
    throw new Error('Messages have different types.');
  }
  var arr1 = m1.toArray();
  var arr2 = m2.toArray();
  var res = [];
  var start = 0;
  var length = arr1.length > arr2.length ? arr1.length : arr2.length;
  if (m1.getJsPbMessageId()) {
    res[0] = m1.getJsPbMessageId();
    start = 1;
  }
  for (var i = start; i < length; i++) {
    if (!jspb.Message.compareFields(arr1[i], arr2[i])) {
      res[i] = arr2[i];
    }
  }
  return new m1.constructor(res);
};


/**
 * Tests whether two messages are equal.
 * @param {jspb.Message|undefined} m1 The first message object.
 * @param {jspb.Message|undefined} m2 The second message object.
 * @return {boolean} true if both messages are null/undefined, or if both are
 *     of the same type and have the same field values.
 */
jspb.Message.equals = function(m1, m2) {
  return m1 == m2 || (!!(m1 && m2) && (m1 instanceof m2.constructor) &&
      jspb.Message.compareFields(m1.toArray(), m2.toArray()));
};


/**
 * Compares two message extension fields recursively.
 * @param {!Object} extension1 The first field.
 * @param {!Object} extension2 The second field.
 * @return {boolean} true if the extensions are null/undefined, or otherwise
 *     equal.
 */
jspb.Message.compareExtensions = function(extension1, extension2) {
  extension1 = extension1 || {};
  extension2 = extension2 || {};

  var keys = {};
  for (var name in extension1) {
    keys[name] = 0;
  }
  for (var name in extension2) {
    keys[name] = 0;
  }
  for (name in keys) {
    if (!jspb.Message.compareFields(extension1[name], extension2[name])) {
      return false;
    }
  }
  return true;
};


/**
 * Compares two message fields recursively.
 * @param {*} field1 The first field.
 * @param {*} field2 The second field.
 * @return {boolean} true if the fields are null/undefined, or otherwise equal.
 */
jspb.Message.compareFields = function(field1, field2) {
  // If the fields are trivially equal, they're equal.
  if (field1 == field2) return true;

  // If the fields aren't trivially equal and one of them isn't an object,
  // they can't possibly be equal.
  if (!goog.isObject(field1) || !goog.isObject(field2)) {
    return false;
  }

  // We have two objects. If they're different types, they're not equal.
  field1 = /** @type {!Object} */(field1);
  field2 = /** @type {!Object} */(field2);
  if (field1.constructor != field2.constructor) return false;

  // If both are Uint8Arrays, compare them element-by-element.
  if (jspb.Message.SUPPORTS_UINT8ARRAY_ && field1.constructor === Uint8Array) {
    var bytes1 = /** @type {!Uint8Array} */(field1);
    var bytes2 = /** @type {!Uint8Array} */(field2);
    if (bytes1.length != bytes2.length) return false;
    for (var i = 0; i < bytes1.length; i++) {
      if (bytes1[i] != bytes2[i]) return false;
    }
    return true;
  }

  // If they're both Arrays, compare them element by element except for the
  // optional extension objects at the end, which we compare separately.
  if (field1.constructor === Array) {
    var extension1 = undefined;
    var extension2 = undefined;

    var length = Math.max(field1.length, field2.length);
    for (var i = 0; i < length; i++) {
      var val1 = field1[i];
      var val2 = field2[i];

      if (val1 && (val1.constructor == Object)) {
        goog.asserts.assert(extension1 === undefined);
        goog.asserts.assert(i === field1.length - 1);
        extension1 = val1;
        val1 = undefined;
      }

      if (val2 && (val2.constructor == Object)) {
        goog.asserts.assert(extension2 === undefined);
        goog.asserts.assert(i === field2.length - 1);
        extension2 = val2;
        val2 = undefined;
      }

      if (!jspb.Message.compareFields(val1, val2)) {
        return false;
      }
    }

    if (extension1 || extension2) {
      extension1 = extension1 || {};
      extension2 = extension2 || {};
      return jspb.Message.compareExtensions(extension1, extension2);
    }

    return true;
  }

  // If they're both plain Objects (i.e. extensions), compare them as
  // extensions.
  if (field1.constructor === Object) {
    return jspb.Message.compareExtensions(field1, field2);
  }

  throw new Error('Invalid type in JSPB array');
};


/**
 * Templated, type-safe cloneMessage definition.
 * @return {THIS}
 * @this {THIS}
 * @template THIS
 */
jspb.Message.prototype.cloneMessage = function() {
  return jspb.Message.cloneMessage(/** @type {!jspb.Message} */ (this));
};

/**
 * Alias clone to cloneMessage. goog.object.unsafeClone uses clone to
 * efficiently copy objects. Without this alias, copying jspb messages comes
 * with a large performance penalty.
 * @return {THIS}
 * @this {THIS}
 * @template THIS
 */
jspb.Message.prototype.clone = function() {
  return jspb.Message.cloneMessage(/** @type {!jspb.Message} */ (this));
};

/**
 * Static clone function. NOTE: A type-safe method called "cloneMessage"
 * exists
 * on each generated JsPb class. Do not call this function directly.
 * @param {!jspb.Message} msg A message to clone.
 * @return {!jspb.Message} A deep clone of the given message.
 */
jspb.Message.clone = function(msg) {
  // Although we could include the wrappers, we leave them out here.
  return jspb.Message.cloneMessage(msg);
};


/**
 * @param {!jspb.Message} msg A message to clone.
 * @return {!jspb.Message} A deep clone of the given message.
 * @protected
 */
jspb.Message.cloneMessage = function(msg) {
  // Although we could include the wrappers, we leave them out here.
  return new msg.constructor(jspb.Message.clone_(msg.toArray()));
};


/**
 * Takes 2 messages of the same type and copies the contents of the first
 * message into the second. After this the 2 messages will equals in terms of
 * value semantics but share no state. All data in the destination message will
 * be overridden.
 *
 * @param {MESSAGE} fromMessage Message that will be copied into toMessage.
 * @param {MESSAGE} toMessage Message which will receive a copy of fromMessage
 *     as its contents.
 * @template MESSAGE
 */
jspb.Message.copyInto = function(fromMessage, toMessage) {
  goog.asserts.assertInstanceof(fromMessage, jspb.Message);
  goog.asserts.assertInstanceof(toMessage, jspb.Message);
  goog.asserts.assert(fromMessage.constructor == toMessage.constructor,
      'Copy source and target message should have the same type.');
  var copyOfFrom = jspb.Message.clone(fromMessage);

  var to = toMessage.toArray();
  var from = copyOfFrom.toArray();

  // Empty destination in case it has more values at the end of the array.
  to.length = 0;
  // and then copy everything from the new to the existing message.
  for (var i = 0; i < from.length; i++) {
    to[i] = from[i];
  }

  // This is either null or empty for a fresh copy.
  toMessage.wrappers_ = copyOfFrom.wrappers_;
  // Just a reference into the shared array.
  toMessage.extensionObject_ = copyOfFrom.extensionObject_;
};


/**
 * Helper for cloning an internal JsPb object.
 * @param {!Object} obj A JsPb object, eg, a field, to be cloned.
 * @return {!Object} A clone of the input object.
 * @private
 */
jspb.Message.clone_ = function(obj) {
  var o;
  if (goog.isArray(obj)) {
    // Allocate array of correct size.
    var clonedArray = new Array(obj.length);
    // Use array iteration where possible because it is faster than for-in.
    for (var i = 0; i < obj.length; i++) {
      if ((o = obj[i]) != null) {
        clonedArray[i] = typeof o == 'object' ? jspb.Message.clone_(o) : o;
      }
    }
    return clonedArray;
  }
  if (jspb.Message.SUPPORTS_UINT8ARRAY_ && obj instanceof Uint8Array) {
    return new Uint8Array(obj);
  }
  var clone = {};
  for (var key in obj) {
    if ((o = obj[key]) != null) {
      clone[key] = typeof o == 'object' ? jspb.Message.clone_(o) : o;
    }
  }
  return clone;
};


/**
 * Registers a JsPb message type id with its constructor.
 * @param {string} id The id for this type of message.
 * @param {Function} constructor The message constructor.
 */
jspb.Message.registerMessageType = function(id, constructor) {
  jspb.Message.registry_[id] = constructor;
  // This is needed so we can later access messageId directly on the contructor,
  // otherwise it is not available due to 'property collapsing' by the compiler.
  constructor.messageId = id;
};


/**
 * The registry of message ids to message constructors.
 * @private
 */
jspb.Message.registry_ = {};


/**
 * The extensions registered on MessageSet. This is a map of extension
 * field number to field info object. This should be considered as a
 * private API.
 *
 * This is similar to [jspb class name].extensions object for
 * non-MessageSet. We special case MessageSet so that we do not need
 * to goog.require MessageSet from classes that extends MessageSet.
 *
 * @type {!Object.<number, jspb.ExtensionFieldInfo>}
 */
jspb.Message.messageSetExtensions = {};
jspb.Message.messageSetExtensionsBinary = {};