aboutsummaryrefslogtreecommitdiffhomepage
path: root/js/binary/reader.js
blob: d5d698f79d8b8ff4e4eac5f41e398efe20c67fed (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
// 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 This file contains utilities for converting binary,
 * wire-format protocol buffers into Javascript data structures.
 *
 * jspb's BinaryReader class wraps the BinaryDecoder class to add methods
 * that understand the protocol buffer syntax and can do the type checking and
 * bookkeeping necessary to parse trees of nested messages.
 *
 * Major caveat - Users of this library _must_ keep their Javascript proto
 * parsing code in sync with the original .proto file - presumably you'll be
 * using the typed jspb code generator, but if you bypass that you'll need
 * to keep things in sync by hand.
 *
 * @author aappleby@google.com (Austin Appleby)
 */

goog.provide('jspb.BinaryReader');

goog.require('goog.asserts');
goog.require('jspb.BinaryConstants');
goog.require('jspb.BinaryDecoder');



/**
 * BinaryReader implements the decoders for all the wire types specified in
 * https://developers.google.com/protocol-buffers/docs/encoding.
 *
 * @param {jspb.ByteSource=} opt_bytes The bytes we're reading from.
 * @param {number=} opt_start The optional offset to start reading at.
 * @param {number=} opt_length The optional length of the block to read -
 *     we'll throw an assertion if we go off the end of the block.
 * @constructor
 * @struct
 */
jspb.BinaryReader = function(opt_bytes, opt_start, opt_length) {
  /**
   * Wire-format decoder.
   * @private {!jspb.BinaryDecoder}
   */
  this.decoder_ = jspb.BinaryDecoder.alloc(opt_bytes, opt_start, opt_length);

  /**
   * Cursor immediately before the field tag.
   * @private {number}
   */
  this.fieldCursor_ = this.decoder_.getCursor();

  /**
   * Field number of the next field in the buffer, filled in by nextField().
   * @private {number}
   */
  this.nextField_ = jspb.BinaryConstants.INVALID_FIELD_NUMBER;

  /**
   * Wire type of the next proto field in the buffer, filled in by
   * nextField().
   * @private {jspb.BinaryConstants.WireType}
   */
  this.nextWireType_ = jspb.BinaryConstants.WireType.INVALID;

  /**
   * Set to true if this reader encountered an error due to corrupt data.
   * @private {boolean}
   */
  this.error_ = false;

  /**
   * User-defined reader callbacks.
   * @private {Object.<string, function(!jspb.BinaryReader):*>}
   */
  this.readCallbacks_ = null;
};


/**
 * Global pool of BinaryReader instances.
 * @private {!Array.<!jspb.BinaryReader>}
 */
jspb.BinaryReader.instanceCache_ = [];


/**
 * Pops an instance off the instance cache, or creates one if the cache is
 * empty.
 * @param {jspb.ByteSource=} opt_bytes The bytes we're reading from.
 * @param {number=} opt_start The optional offset to start reading at.
 * @param {number=} opt_length The optional length of the block to read -
 *     we'll throw an assertion if we go off the end of the block.
 * @return {!jspb.BinaryReader}
 */
jspb.BinaryReader.alloc =
    function(opt_bytes, opt_start, opt_length) {
  if (jspb.BinaryReader.instanceCache_.length) {
    var newReader = jspb.BinaryReader.instanceCache_.pop();
    if (opt_bytes) {
      newReader.decoder_.setBlock(opt_bytes, opt_start, opt_length);
    }
    return newReader;
  } else {
    return new jspb.BinaryReader(opt_bytes, opt_start, opt_length);
  }
};


/**
 * Alias for the above method.
 * @param {jspb.ByteSource=} opt_bytes The bytes we're reading from.
 * @param {number=} opt_start The optional offset to start reading at.
 * @param {number=} opt_length The optional length of the block to read -
 *     we'll throw an assertion if we go off the end of the block.
 * @return {!jspb.BinaryReader}
 */
jspb.BinaryReader.prototype.alloc = jspb.BinaryReader.alloc;


/**
 * Puts this instance back in the instance cache.
 */
jspb.BinaryReader.prototype.free = function() {
  this.decoder_.clear();
  this.nextField_ = jspb.BinaryConstants.INVALID_FIELD_NUMBER;
  this.nextWireType_ = jspb.BinaryConstants.WireType.INVALID;
  this.error_ = false;
  this.readCallbacks_ = null;

  if (jspb.BinaryReader.instanceCache_.length < 100) {
    jspb.BinaryReader.instanceCache_.push(this);
  }
};


/**
 * Returns the cursor immediately before the current field's tag.
 * @return {number} The internal read cursor.
 */
jspb.BinaryReader.prototype.getFieldCursor = function() {
  return this.fieldCursor_;
};


/**
 * Returns the internal read cursor.
 * @return {number} The internal read cursor.
 */
jspb.BinaryReader.prototype.getCursor = function() {
  return this.decoder_.getCursor();
};


/**
 * Returns the raw buffer.
 * @return {?Uint8Array} The raw buffer.
 */
jspb.BinaryReader.prototype.getBuffer = function() {
  return this.decoder_.getBuffer();
};


/**
 * @return {number} The field number of the next field in the buffer, or
 *     INVALID_FIELD_NUMBER if there is no next field.
 */
jspb.BinaryReader.prototype.getFieldNumber = function() {
  return this.nextField_;
};


/**
 * @return {jspb.BinaryConstants.WireType} The wire type of the next field
 *     in the stream, or WireType.INVALID if there is no next field.
 */
jspb.BinaryReader.prototype.getWireType = function() {
  return this.nextWireType_;
};


/**
 * @return {boolean} Whether the current wire type is an end-group tag. Used as
 * an exit condition in decoder loops in generated code.
 */
jspb.BinaryReader.prototype.isEndGroup = function() {
  return this.nextWireType_ == jspb.BinaryConstants.WireType.END_GROUP;
};


/**
 * Returns true if this reader hit an error due to corrupt data.
 * @return {boolean}
 */
jspb.BinaryReader.prototype.getError = function() {
  return this.error_ || this.decoder_.getError();
};


/**
 * Points this reader at a new block of bytes.
 * @param {!Uint8Array} bytes The block of bytes we're reading from.
 * @param {number} start The offset to start reading at.
 * @param {number} length The length of the block to read.
 */
jspb.BinaryReader.prototype.setBlock = function(bytes, start, length) {
  this.decoder_.setBlock(bytes, start, length);
  this.nextField_ = jspb.BinaryConstants.INVALID_FIELD_NUMBER;
  this.nextWireType_ = jspb.BinaryConstants.WireType.INVALID;
};


/**
 * Rewinds the stream cursor to the beginning of the buffer and resets all
 * internal state.
 */
jspb.BinaryReader.prototype.reset = function() {
  this.decoder_.reset();
  this.nextField_ = jspb.BinaryConstants.INVALID_FIELD_NUMBER;
  this.nextWireType_ = jspb.BinaryConstants.WireType.INVALID;
};


/**
 * Advances the stream cursor by the given number of bytes.
 * @param {number} count The number of bytes to advance by.
 */
jspb.BinaryReader.prototype.advance = function(count) {
  this.decoder_.advance(count);
};


/**
 * Reads the next field header in the stream if there is one, returns true if
 * we saw a valid field header or false if we've read the whole stream.
 * Throws an error if we encountered a deprecated START_GROUP/END_GROUP field.
 * @return {boolean} True if the stream contains more fields.
 */
jspb.BinaryReader.prototype.nextField = function() {
  // If we're at the end of the block, there are no more fields.
  if (this.decoder_.atEnd()) {
    return false;
  }

  // If we hit an error decoding the previous field, stop now before we
  // try to decode anything else
  if (this.getError()) {
    goog.asserts.fail('Decoder hit an error');
    return false;
  }

  // Otherwise just read the header of the next field.
  this.fieldCursor_ = this.decoder_.getCursor();
  var header = this.decoder_.readUnsignedVarint32();

  var nextField = header >>> 3;
  var nextWireType = /** @type {jspb.BinaryConstants.WireType} */
      (header & 0x7);

  // If the wire type isn't one of the valid ones, something's broken.
  if (nextWireType != jspb.BinaryConstants.WireType.VARINT &&
      nextWireType != jspb.BinaryConstants.WireType.FIXED32 &&
      nextWireType != jspb.BinaryConstants.WireType.FIXED64 &&
      nextWireType != jspb.BinaryConstants.WireType.DELIMITED &&
      nextWireType != jspb.BinaryConstants.WireType.START_GROUP &&
      nextWireType != jspb.BinaryConstants.WireType.END_GROUP) {
    goog.asserts.fail('Invalid wire type');
    this.error_ = true;
    return false;
  }

  this.nextField_ = nextField;
  this.nextWireType_ = nextWireType;

  return true;
};


/**
 * Winds the reader back to just before this field's header.
 */
jspb.BinaryReader.prototype.unskipHeader = function() {
  this.decoder_.unskipVarint((this.nextField_ << 3) | this.nextWireType_);
};


/**
 * Skips all contiguous fields whose header matches the one we just read.
 */
jspb.BinaryReader.prototype.skipMatchingFields = function() {
  var field = this.nextField_;
  this.unskipHeader();

  while (this.nextField() && (this.getFieldNumber() == field)) {
    this.skipField();
  }

  if (!this.decoder_.atEnd()) {
    this.unskipHeader();
  }
};


/**
 * Skips over the next varint field in the binary stream.
 */
jspb.BinaryReader.prototype.skipVarintField = function() {
  if (this.nextWireType_ != jspb.BinaryConstants.WireType.VARINT) {
    goog.asserts.fail('Invalid wire type for skipVarintField');
    this.skipField();
    return;
  }

  this.decoder_.skipVarint();
};


/**
 * Skips over the next delimited field in the binary stream.
 */
jspb.BinaryReader.prototype.skipDelimitedField = function() {
  if (this.nextWireType_ != jspb.BinaryConstants.WireType.DELIMITED) {
    goog.asserts.fail('Invalid wire type for skipDelimitedField');
    this.skipField();
    return;
  }

  var length = this.decoder_.readUnsignedVarint32();
  this.decoder_.advance(length);
};


/**
 * Skips over the next fixed32 field in the binary stream.
 */
jspb.BinaryReader.prototype.skipFixed32Field = function() {
  if (this.nextWireType_ != jspb.BinaryConstants.WireType.FIXED32) {
    goog.asserts.fail('Invalid wire type for skipFixed32Field');
    this.skipField();
    return;
  }

  this.decoder_.advance(4);
};


/**
 * Skips over the next fixed64 field in the binary stream.
 */
jspb.BinaryReader.prototype.skipFixed64Field = function() {
  if (this.nextWireType_ != jspb.BinaryConstants.WireType.FIXED64) {
    goog.asserts.fail('Invalid wire type for skipFixed64Field');
    this.skipField();
    return;
  }

  this.decoder_.advance(8);
};


/**
 * Skips over the next group field in the binary stream.
 */
jspb.BinaryReader.prototype.skipGroup = function() {
  // Keep a stack of start-group tags that must be matched by end-group tags.
  var nestedGroups = [this.nextField_];
  do {
    if (!this.nextField()) {
      goog.asserts.fail('Unmatched start-group tag: stream EOF');
      this.error_ = true;
      return;
    }
    if (this.nextWireType_ ==
        jspb.BinaryConstants.WireType.START_GROUP) {
      // Nested group start.
      nestedGroups.push(this.nextField_);
    } else if (this.nextWireType_ ==
               jspb.BinaryConstants.WireType.END_GROUP) {
      // Group end: check that it matches top-of-stack.
      if (this.nextField_ != nestedGroups.pop()) {
        goog.asserts.fail('Unmatched end-group tag');
        this.error_ = true;
        return;
      }
    }
  } while (nestedGroups.length > 0);
};


/**
 * Skips over the next field in the binary stream - this is useful if we're
 * decoding a message that contain unknown fields.
 */
jspb.BinaryReader.prototype.skipField = function() {
  switch (this.nextWireType_) {
    case jspb.BinaryConstants.WireType.VARINT:
      this.skipVarintField();
      break;
    case jspb.BinaryConstants.WireType.FIXED64:
      this.skipFixed64Field();
      break;
    case jspb.BinaryConstants.WireType.DELIMITED:
      this.skipDelimitedField();
      break;
    case jspb.BinaryConstants.WireType.FIXED32:
      this.skipFixed32Field();
      break;
    case jspb.BinaryConstants.WireType.START_GROUP:
      this.skipGroup();
      break;
    default:
      goog.asserts.fail('Invalid wire encoding for field.');
  }
};


/**
 * Registers a user-defined read callback.
 * @param {string} callbackName
 * @param {function(!jspb.BinaryReader):*} callback
 */
jspb.BinaryReader.prototype.registerReadCallback =
    function(callbackName, callback) {
  if (goog.isNull(this.readCallbacks_)) {
    this.readCallbacks_ = {};
  }
  goog.asserts.assert(!this.readCallbacks_[callbackName]);
  this.readCallbacks_[callbackName] = callback;
};


/**
 * Runs a registered read callback.
 * @param {string} callbackName The name the callback is registered under.
 * @return {*} The value returned by the callback.
 */
jspb.BinaryReader.prototype.runReadCallback = function(callbackName) {
  goog.asserts.assert(!goog.isNull(this.readCallbacks_));
  var callback = this.readCallbacks_[callbackName];
  goog.asserts.assert(callback);
  return callback(this);
};


/**
 * Reads a field of any valid non-message type from the binary stream.
 * @param {jspb.BinaryConstants.FieldType} fieldType
 * @return {jspb.AnyFieldType}
 */
jspb.BinaryReader.prototype.readAny = function(fieldType) {
  this.nextWireType_ = jspb.BinaryConstants.FieldTypeToWireType(fieldType);
  var fieldTypes = jspb.BinaryConstants.FieldType;
  switch (fieldType) {
    case fieldTypes.DOUBLE:
      return this.readDouble();
    case fieldTypes.FLOAT:
      return this.readFloat();
    case fieldTypes.INT64:
      return this.readInt64();
    case fieldTypes.UINT64:
      return this.readUint64();
    case fieldTypes.INT32:
      return this.readInt32();
    case fieldTypes.FIXED64:
      return this.readFixed64();
    case fieldTypes.FIXED32:
      return this.readFixed32();
    case fieldTypes.BOOL:
      return this.readBool();
    case fieldTypes.STRING:
      return this.readString();
    case fieldTypes.GROUP:
      goog.asserts.fail('Group field type not supported in readAny()');
    case fieldTypes.MESSAGE:
      goog.asserts.fail('Message field type not supported in readAny()');
    case fieldTypes.BYTES:
      return this.readBytes();
    case fieldTypes.UINT32:
      return this.readUint32();
    case fieldTypes.ENUM:
      return this.readEnum();
    case fieldTypes.SFIXED32:
      return this.readSfixed32();
    case fieldTypes.SFIXED64:
      return this.readSfixed64();
    case fieldTypes.SINT32:
      return this.readSint32();
    case fieldTypes.SINT64:
      return this.readSint64();
    case fieldTypes.FHASH64:
      return this.readFixedHash64();
    case fieldTypes.VHASH64:
      return this.readVarintHash64();
    default:
      goog.asserts.fail('Invalid field type in readAny()');
  }
  return 0;
};


/**
 * Deserialize a proto into the provided message object using the provided
 * reader function. This function is templated as we currently have one client
 * who is using manual deserialization instead of the code-generated versions.
 * @template T
 * @param {T} message
 * @param {function(T, !jspb.BinaryReader)} reader
 */
jspb.BinaryReader.prototype.readMessage = function(message, reader) {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.DELIMITED);

  // Save the current endpoint of the decoder and move it to the end of the
  // embedded message.
  var oldEnd = this.decoder_.getEnd();
  var length = this.decoder_.readUnsignedVarint32();
  var newEnd = this.decoder_.getCursor() + length;
  this.decoder_.setEnd(newEnd);

  // Deserialize the embedded message.
  reader(message, this);

  // Advance the decoder past the embedded message and restore the endpoint.
  this.decoder_.setCursor(newEnd);
  this.decoder_.setEnd(oldEnd);
};


/**
 * Deserialize a proto into the provided message object using the provided
 * reader function, assuming that the message is serialized as a group
 * with the given tag.
 * @template T
 * @param {number} field
 * @param {T} message
 * @param {function(T, !jspb.BinaryReader)} reader
 */
jspb.BinaryReader.prototype.readGroup =
    function(field, message, reader) {
  // Ensure that the wire type is correct.
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.START_GROUP);
  // Ensure that the field number is correct.
  goog.asserts.assert(this.nextField_ == field);

  // Deserialize the message. The deserialization will stop at an END_GROUP tag.
  reader(message, this);

  if (!this.error_ &&
      this.nextWireType_ != jspb.BinaryConstants.WireType.END_GROUP) {
    goog.asserts.fail('Group submessage did not end with an END_GROUP tag');
    this.error_ = true;
  }
};


/**
 * Return a decoder that wraps the current delimited field.
 * @return {!jspb.BinaryDecoder}
 */
jspb.BinaryReader.prototype.getFieldDecoder = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.DELIMITED);

  var length = this.decoder_.readUnsignedVarint32();
  var start = this.decoder_.getCursor();
  var end = start + length;

  var innerDecoder =
      jspb.BinaryDecoder.alloc(this.decoder_.getBuffer(), start, length);
  this.decoder_.setCursor(end);
  return innerDecoder;
};


/**
 * Reads a signed 32-bit integer field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * @return {number} The value of the signed 32-bit integer field.
 */
jspb.BinaryReader.prototype.readInt32 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readSignedVarint32();
};


/**
 * Reads a signed 32-bit integer field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * Returns the value as a string.
 *
 * @return {string} The value of the signed 32-bit integer field as a decimal
 * string.
 */
jspb.BinaryReader.prototype.readInt32String = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readSignedVarint32String();
};


/**
 * Reads a signed 64-bit integer field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * @return {number} The value of the signed 64-bit integer field.
 */
jspb.BinaryReader.prototype.readInt64 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readSignedVarint64();
};


/**
 * Reads a signed 64-bit integer field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * Returns the value as a string.
 *
 * @return {string} The value of the signed 64-bit integer field as a decimal
 * string.
 */
jspb.BinaryReader.prototype.readInt64String = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readSignedVarint64String();
};


/**
 * Reads an unsigned 32-bit integer field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * @return {number} The value of the unsigned 32-bit integer field.
 */
jspb.BinaryReader.prototype.readUint32 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readUnsignedVarint32();
};


/**
 * Reads an unsigned 32-bit integer field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * Returns the value as a string.
 *
 * @return {string} The value of the unsigned 32-bit integer field as a decimal
 * string.
 */
jspb.BinaryReader.prototype.readUint32String = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readUnsignedVarint32String();
};


/**
 * Reads an unsigned 64-bit integer field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * @return {number} The value of the unsigned 64-bit integer field.
 */
jspb.BinaryReader.prototype.readUint64 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readUnsignedVarint64();
};


/**
 * Reads an unsigned 64-bit integer field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * Returns the value as a string.
 *
 * @return {string} The value of the unsigned 64-bit integer field as a decimal
 * string.
 */
jspb.BinaryReader.prototype.readUint64String = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readUnsignedVarint64String();
};


/**
 * Reads a signed zigzag-encoded 32-bit integer field from the binary stream,
 * or throws an error if the next field in the stream is not of the correct
 * wire type.
 *
 * @return {number} The value of the signed 32-bit integer field.
 */
jspb.BinaryReader.prototype.readSint32 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readZigzagVarint32();
};


/**
 * Reads a signed zigzag-encoded 64-bit integer field from the binary stream,
 * or throws an error if the next field in the stream is not of the correct
 * wire type.
 *
 * @return {number} The value of the signed 64-bit integer field.
 */
jspb.BinaryReader.prototype.readSint64 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readZigzagVarint64();
};


/**
 * Reads a signed zigzag-encoded 64-bit integer field from the binary stream,
 * or throws an error if the next field in the stream is not of the correct
 * wire type.
 *
 * @return {string} The value of the signed 64-bit integer field as a decimal string.
 */
jspb.BinaryReader.prototype.readSint64String = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readZigzagVarint64String();
};


/**
 * Reads an unsigned 32-bit fixed-length integer fiield from the binary stream,
 * or throws an error if the next field in the stream is not of the correct
 * wire type.
 *
 * @return {number} The value of the double field.
 */
jspb.BinaryReader.prototype.readFixed32 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED32);
  return this.decoder_.readUint32();
};


/**
 * Reads an unsigned 64-bit fixed-length integer fiield from the binary stream,
 * or throws an error if the next field in the stream is not of the correct
 * wire type.
 *
 * @return {number} The value of the float field.
 */
jspb.BinaryReader.prototype.readFixed64 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED64);
  return this.decoder_.readUint64();
};


/**
 * Reads a signed 64-bit integer field from the binary stream as a string, or
 * throws an error if the next field in the stream is not of the correct wire
 * type.
 *
 * Returns the value as a string.
 *
 * @return {string} The value of the unsigned 64-bit integer field as a decimal
 * string.
 */
jspb.BinaryReader.prototype.readFixed64String = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED64);
  return this.decoder_.readUint64String();
};


/**
 * Reads a signed 32-bit fixed-length integer fiield from the binary stream, or
 * throws an error if the next field in the stream is not of the correct wire
 * type.
 *
 * @return {number} The value of the signed 32-bit integer field.
 */
jspb.BinaryReader.prototype.readSfixed32 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED32);
  return this.decoder_.readInt32();
};


/**
 * Reads a signed 32-bit fixed-length integer fiield from the binary stream, or
 * throws an error if the next field in the stream is not of the correct wire
 * type.
 *
 * @return {string} The value of the signed 32-bit integer field as a decimal
 * string.
 */
jspb.BinaryReader.prototype.readSfixed32String = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED32);
  return this.decoder_.readInt32().toString();
};


/**
 * Reads a signed 64-bit fixed-length integer fiield from the binary stream, or
 * throws an error if the next field in the stream is not of the correct wire
 * type.
 *
 * @return {number} The value of the sfixed64 field.
 */
jspb.BinaryReader.prototype.readSfixed64 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED64);
  return this.decoder_.readInt64();
};


/**
 * Reads a signed 64-bit fixed-length integer fiield from the binary stream, or
 * throws an error if the next field in the stream is not of the correct wire
 * type.
 *
 * Returns the value as a string.
 *
 * @return {string} The value of the sfixed64 field as a decimal string.
 */
jspb.BinaryReader.prototype.readSfixed64String = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED64);
  return this.decoder_.readInt64String();
};


/**
 * Reads a 32-bit floating-point field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * @return {number} The value of the float field.
 */
jspb.BinaryReader.prototype.readFloat = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED32);
  return this.decoder_.readFloat();
};


/**
 * Reads a 64-bit floating-point field from the binary stream, or throws an
 * error if the next field in the stream is not of the correct wire type.
 *
 * @return {number} The value of the double field.
 */
jspb.BinaryReader.prototype.readDouble = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED64);
  return this.decoder_.readDouble();
};


/**
 * Reads a boolean field from the binary stream, or throws an error if the next
 * field in the stream is not of the correct wire type.
 *
 * @return {boolean} The value of the boolean field.
 */
jspb.BinaryReader.prototype.readBool = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return !!this.decoder_.readUnsignedVarint32();
};


/**
 * Reads an enum field from the binary stream, or throws an error if the next
 * field in the stream is not of the correct wire type.
 *
 * @return {number} The value of the enum field.
 */
jspb.BinaryReader.prototype.readEnum = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readSignedVarint64();
};


/**
 * Reads a string field from the binary stream, or throws an error if the next
 * field in the stream is not of the correct wire type.
 *
 * @return {string} The value of the string field.
 */
jspb.BinaryReader.prototype.readString = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.DELIMITED);
  var length = this.decoder_.readUnsignedVarint32();
  return this.decoder_.readString(length);
};


/**
 * Reads a length-prefixed block of bytes from the binary stream, or returns
 * null if the next field in the stream has an invalid length value.
 *
 * @return {!Uint8Array} The block of bytes.
 */
jspb.BinaryReader.prototype.readBytes = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.DELIMITED);
  var length = this.decoder_.readUnsignedVarint32();
  return this.decoder_.readBytes(length);
};


/**
 * Reads a 64-bit varint or fixed64 field from the stream and returns it as a
 * 8-character Unicode string for use as a hash table key, or throws an error
 * if the next field in the stream is not of the correct wire type.
 *
 * @return {string} The hash value.
 */
jspb.BinaryReader.prototype.readVarintHash64 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.VARINT);
  return this.decoder_.readVarintHash64();
};


/**
 * Reads a 64-bit varint or fixed64 field from the stream and returns it as a
 * 8-character Unicode string for use as a hash table key, or throws an error
 * if the next field in the stream is not of the correct wire type.
 *
 * @return {string} The hash value.
 */
jspb.BinaryReader.prototype.readFixedHash64 = function() {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.FIXED64);
  return this.decoder_.readFixedHash64();
};


/**
 * Reads a packed scalar field using the supplied raw reader function.
 * @param {function(this:jspb.BinaryDecoder)} decodeMethod
 * @return {!Array}
 * @private
 */
jspb.BinaryReader.prototype.readPackedField_ = function(decodeMethod) {
  goog.asserts.assert(
      this.nextWireType_ == jspb.BinaryConstants.WireType.DELIMITED);
  var length = this.decoder_.readUnsignedVarint32();
  var end = this.decoder_.getCursor() + length;
  var result = [];
  while (this.decoder_.getCursor() < end) {
    // TODO(aappleby): .call is slow
    result.push(decodeMethod.call(this.decoder_));
  }
  return result;
};


/**
 * Reads a packed int32 field, which consists of a length header and a list of
 * signed varints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedInt32 = function() {
  return this.readPackedField_(this.decoder_.readSignedVarint32);
};


/**
 * Reads a packed int32 field, which consists of a length header and a list of
 * signed varints. Returns a list of strings.
 * @return {!Array.<string>}
 */
jspb.BinaryReader.prototype.readPackedInt32String = function() {
  return this.readPackedField_(this.decoder_.readSignedVarint32String);
};


/**
 * Reads a packed int64 field, which consists of a length header and a list of
 * signed varints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedInt64 = function() {
  return this.readPackedField_(this.decoder_.readSignedVarint64);
};


/**
 * Reads a packed int64 field, which consists of a length header and a list of
 * signed varints. Returns a list of strings.
 * @return {!Array.<string>}
 */
jspb.BinaryReader.prototype.readPackedInt64String = function() {
  return this.readPackedField_(this.decoder_.readSignedVarint64String);
};


/**
 * Reads a packed uint32 field, which consists of a length header and a list of
 * unsigned varints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedUint32 = function() {
  return this.readPackedField_(this.decoder_.readUnsignedVarint32);
};


/**
 * Reads a packed uint32 field, which consists of a length header and a list of
 * unsigned varints. Returns a list of strings.
 * @return {!Array.<string>}
 */
jspb.BinaryReader.prototype.readPackedUint32String = function() {
  return this.readPackedField_(this.decoder_.readUnsignedVarint32String);
};


/**
 * Reads a packed uint64 field, which consists of a length header and a list of
 * unsigned varints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedUint64 = function() {
  return this.readPackedField_(this.decoder_.readUnsignedVarint64);
};


/**
 * Reads a packed uint64 field, which consists of a length header and a list of
 * unsigned varints. Returns a list of strings.
 * @return {!Array.<string>}
 */
jspb.BinaryReader.prototype.readPackedUint64String = function() {
  return this.readPackedField_(this.decoder_.readUnsignedVarint64String);
};


/**
 * Reads a packed sint32 field, which consists of a length header and a list of
 * zigzag varints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedSint32 = function() {
  return this.readPackedField_(this.decoder_.readZigzagVarint32);
};


/**
 * Reads a packed sint64 field, which consists of a length header and a list of
 * zigzag varints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedSint64 = function() {
  return this.readPackedField_(this.decoder_.readZigzagVarint64);
};


/**
 * Reads a packed sint64 field, which consists of a length header and a list of
 * zigzag varints.  Returns a list of strings.
 * @return {!Array.<string>}
 */
jspb.BinaryReader.prototype.readPackedSint64String = function() {
  return this.readPackedField_(this.decoder_.readZigzagVarint64String);
};


/**
 * Reads a packed fixed32 field, which consists of a length header and a list
 * of unsigned 32-bit ints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedFixed32 = function() {
  return this.readPackedField_(this.decoder_.readUint32);
};


/**
 * Reads a packed fixed64 field, which consists of a length header and a list
 * of unsigned 64-bit ints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedFixed64 = function() {
  return this.readPackedField_(this.decoder_.readUint64);
};


/**
 * Reads a packed fixed64 field, which consists of a length header and a list
 * of unsigned 64-bit ints.  Returns a list of strings.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedFixed64String = function() {
  return this.readPackedField_(this.decoder_.readUint64String);
};


/**
 * Reads a packed sfixed32 field, which consists of a length header and a list
 * of 32-bit ints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedSfixed32 = function() {
  return this.readPackedField_(this.decoder_.readInt32);
};


/**
 * Reads a packed sfixed64 field, which consists of a length header and a list
 * of 64-bit ints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedSfixed64 = function() {
  return this.readPackedField_(this.decoder_.readInt64);
};


/**
 * Reads a packed sfixed64 field, which consists of a length header and a list
 * of 64-bit ints.  Returns a list of strings.
 * @return {!Array.<string>}
 */
jspb.BinaryReader.prototype.readPackedSfixed64String = function() {
  return this.readPackedField_(this.decoder_.readInt64String);
};


/**
 * Reads a packed float field, which consists of a length header and a list of
 * floats.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedFloat = function() {
  return this.readPackedField_(this.decoder_.readFloat);
};


/**
 * Reads a packed double field, which consists of a length header and a list of
 * doubles.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedDouble = function() {
  return this.readPackedField_(this.decoder_.readDouble);
};


/**
 * Reads a packed bool field, which consists of a length header and a list of
 * unsigned varints.
 * @return {!Array.<boolean>}
 */
jspb.BinaryReader.prototype.readPackedBool = function() {
  return this.readPackedField_(this.decoder_.readBool);
};


/**
 * Reads a packed enum field, which consists of a length header and a list of
 * unsigned varints.
 * @return {!Array.<number>}
 */
jspb.BinaryReader.prototype.readPackedEnum = function() {
  return this.readPackedField_(this.decoder_.readEnum);
};


/**
 * Reads a packed varint hash64 field, which consists of a length header and a
 * list of varint hash64s.
 * @return {!Array.<string>}
 */
jspb.BinaryReader.prototype.readPackedVarintHash64 = function() {
  return this.readPackedField_(this.decoder_.readVarintHash64);
};


/**
 * Reads a packed fixed hash64 field, which consists of a length header and a
 * list of fixed hash64s.
 * @return {!Array.<string>}
 */
jspb.BinaryReader.prototype.readPackedFixedHash64 = function() {
  return this.readPackedField_(this.decoder_.readFixedHash64);
};