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
|
// wiredtiger_index.cpp
/**
* Copyright (C) 2014 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kStorage
#include "mongo/platform/basic.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_index.h"
#include <set>
#include "mongo/base/checked_cast.h"
#include "mongo/db/catalog/index_catalog_entry.h"
#include "mongo/db/concurrency/write_conflict_exception.h"
#include "mongo/db/index/index_descriptor.h"
#include "mongo/db/json.h"
#include "mongo/db/service_context.h"
#include "mongo/db/storage/key_string.h"
#include "mongo/db/storage/storage_options.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_customization_hooks.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_global_options.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_record_store.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_session_cache.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_util.h"
#include "mongo/stdx/memory.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/fail_point.h"
#include "mongo/util/hex.h"
#include "mongo/util/log.h"
#include "mongo/util/mongoutils/str.h"
#define TRACING_ENABLED 0
#if TRACING_ENABLED
#define TRACE_CURSOR log() << "WT index (" << (const void*)&_idx << ") "
#define TRACE_INDEX log() << "WT index (" << (const void*)this << ") "
#else
#define TRACE_CURSOR \
if (0) \
log()
#define TRACE_INDEX \
if (0) \
log()
#endif
namespace mongo {
namespace {
MONGO_FP_DECLARE(WTEmulateOutOfOrderNextIndexKey);
using std::string;
using std::vector;
static const int TempKeyMaxSize = 1024; // this goes away with SERVER-3372
static const WiredTigerItem emptyItem(NULL, 0);
// Keystring format 7 was used in 3.3.6 - 3.3.8 development releases.
static const int kKeyStringV0Version = 6;
static const int kKeyStringV1Version = 8;
static const int kMinimumIndexVersion = kKeyStringV0Version;
static const int kMaximumIndexVersion = kKeyStringV1Version;
bool hasFieldNames(const BSONObj& obj) {
BSONForEach(e, obj) {
if (e.fieldName()[0])
return true;
}
return false;
}
BSONObj stripFieldNames(const BSONObj& query) {
if (!hasFieldNames(query))
return query;
BSONObjBuilder bb;
BSONForEach(e, query) {
bb.appendAs(e, StringData());
}
return bb.obj();
}
Status checkKeySize(const BSONObj& key) {
if (key.objsize() >= TempKeyMaxSize) {
string msg = mongoutils::str::stream()
<< "WiredTigerIndex::insert: key too large to index, failing " << ' ' << key.objsize()
<< ' ' << key;
return Status(ErrorCodes::KeyTooLong, msg);
}
return Status::OK();
}
} // namespace
Status WiredTigerIndex::dupKeyError(const BSONObj& key) {
StringBuilder sb;
sb << "E11000 duplicate key error";
sb << " collection: " << _collectionNamespace;
sb << " index: " << _indexName;
sb << " dup key: " << key;
return Status(ErrorCodes::DuplicateKey, sb.str());
}
// static
StatusWith<std::string> WiredTigerIndex::parseIndexOptions(const BSONObj& options) {
StringBuilder ss;
BSONForEach(elem, options) {
if (elem.fieldNameStringData() == "configString") {
Status status = WiredTigerUtil::checkTableCreationOptions(elem);
if (!status.isOK()) {
return status;
}
ss << elem.valueStringData() << ',';
} else {
// Return error on first unrecognized field.
return StatusWith<std::string>(ErrorCodes::InvalidOptions,
str::stream() << '\'' << elem.fieldNameStringData()
<< '\''
<< " is not a supported option.");
}
}
return StatusWith<std::string>(ss.str());
}
// static
StatusWith<std::string> WiredTigerIndex::generateCreateString(const std::string& engineName,
const std::string& sysIndexConfig,
const std::string& collIndexConfig,
const IndexDescriptor& desc) {
str::stream ss;
// Separate out a prefix and suffix in the default string. User configuration will override
// values in the prefix, but not values in the suffix. Page sizes are chosen so that index
// keys (up to 1024 bytes) will not overflow.
ss << "type=file,internal_page_max=16k,leaf_page_max=16k,";
ss << "checksum=on,";
if (wiredTigerGlobalOptions.useIndexPrefixCompression) {
ss << "prefix_compression=true,";
}
ss << "block_compressor=" << wiredTigerGlobalOptions.indexBlockCompressor << ",";
ss << WiredTigerCustomizationHooks::get(getGlobalServiceContext())
->getTableCreateConfig(desc.parentNS());
ss << sysIndexConfig << ",";
ss << collIndexConfig << ",";
// Validate configuration object.
// Raise an error about unrecognized fields that may be introduced in newer versions of
// this storage engine.
// Ensure that 'configString' field is a string. Raise an error if this is not the case.
BSONElement storageEngineElement = desc.getInfoElement("storageEngine");
if (storageEngineElement.isABSONObj()) {
BSONObj storageEngine = storageEngineElement.Obj();
StatusWith<std::string> parseStatus =
parseIndexOptions(storageEngine.getObjectField(engineName));
if (!parseStatus.isOK()) {
return parseStatus;
}
if (!parseStatus.getValue().empty()) {
ss << "," << parseStatus.getValue();
}
}
// WARNING: No user-specified config can appear below this line. These options are required
// for correct behavior of the server.
// Indexes need to store the metadata for collation to work as expected.
ss << ",key_format=u,value_format=u";
// We build v=2 indexes when the featureCompatibilityVersion is 3.4. This means that the server
// supports new index features and we can therefore use KeyString::Version::V1.
const int keyStringVersion = desc.version() >= IndexDescriptor::IndexVersion::kV2
? kKeyStringV1Version
: kKeyStringV0Version;
// Index metadata
ss << ",app_metadata=("
<< "formatVersion=" << keyStringVersion << ',' << "infoObj=" << desc.infoObj().jsonString()
<< "),";
LOG(3) << "index create string: " << ss.ss.str();
return StatusWith<std::string>(ss);
}
int WiredTigerIndex::Create(OperationContext* opCtx,
const std::string& uri,
const std::string& config) {
// Don't use the session from the recovery unit: create should not be used in a transaction
WiredTigerSession session(WiredTigerRecoveryUnit::get(opCtx)->getSessionCache()->conn());
WT_SESSION* s = session.getSession();
LOG(1) << "create uri: " << uri << " config: " << config;
return s->create(s, uri.c_str(), config.c_str());
}
WiredTigerIndex::WiredTigerIndex(OperationContext* ctx,
const std::string& uri,
const IndexDescriptor* desc)
: _ordering(Ordering::make(desc->keyPattern())),
_uri(uri),
_tableId(WiredTigerSession::genTableId()),
_collectionNamespace(desc->parentNS()),
_indexName(desc->indexName()) {
auto version = WiredTigerUtil::checkApplicationMetadataFormatVersion(
ctx, uri, kMinimumIndexVersion, kMaximumIndexVersion);
if (!version.isOK()) {
str::stream ss;
Status versionStatus = version.getStatus();
ss << versionStatus.reason() << " Index: {name: " << desc->indexName()
<< ", ns: " << desc->parentNS() << "} - version too new for this mongod."
<< " See http://dochub.mongodb.org/core/3.4-index-downgrade for detailed"
<< " instructions on how to handle this error.";
Status indexVersionStatus(
ErrorCodes::UnsupportedFormat, ss.ss.str(), versionStatus.location());
fassertFailedWithStatusNoTrace(28579, indexVersionStatus);
}
_keyStringVersion =
version.getValue() == kKeyStringV1Version ? KeyString::Version::V1 : KeyString::Version::V0;
}
Status WiredTigerIndex::insert(OperationContext* opCtx,
const BSONObj& key,
const RecordId& id,
bool dupsAllowed) {
invariant(id.isNormal());
dassert(!hasFieldNames(key));
Status s = checkKeySize(key);
if (!s.isOK())
return s;
WiredTigerCursor curwrap(_uri, _tableId, false, opCtx);
curwrap.assertInActiveTxn();
WT_CURSOR* c = curwrap.get();
return _insert(c, key, id, dupsAllowed);
}
void WiredTigerIndex::unindex(OperationContext* opCtx,
const BSONObj& key,
const RecordId& id,
bool dupsAllowed) {
invariant(id.isNormal());
dassert(!hasFieldNames(key));
WiredTigerCursor curwrap(_uri, _tableId, false, opCtx);
curwrap.assertInActiveTxn();
WT_CURSOR* c = curwrap.get();
invariant(c);
_unindex(c, key, id, dupsAllowed);
}
void WiredTigerIndex::fullValidate(OperationContext* opCtx,
long long* numKeysOut,
ValidateResults* fullResults) const {
if (fullResults && !WiredTigerRecoveryUnit::get(opCtx)->getSessionCache()->isEphemeral()) {
int err = WiredTigerUtil::verifyTable(opCtx, _uri, &(fullResults->errors));
if (err == EBUSY) {
const char* msg = "verify() returned EBUSY. Not treating as invalid.";
warning() << msg;
fullResults->warnings.push_back(msg);
} else if (err) {
std::string msg = str::stream() << "verify() returned " << wiredtiger_strerror(err)
<< ". "
<< "This indicates structural damage. "
<< "Not examining individual index entries.";
error() << msg;
fullResults->errors.push_back(msg);
fullResults->valid = false;
return;
}
}
auto cursor = newCursor(opCtx);
long long count = 0;
TRACE_INDEX << " fullValidate";
const auto requestedInfo = TRACING_ENABLED ? Cursor::kKeyAndLoc : Cursor::kJustExistance;
for (auto kv = cursor->seek(BSONObj(), true, requestedInfo); kv; kv = cursor->next()) {
TRACE_INDEX << "\t" << kv->key << ' ' << kv->loc;
count++;
}
if (numKeysOut) {
*numKeysOut = count;
}
}
bool WiredTigerIndex::appendCustomStats(OperationContext* opCtx,
BSONObjBuilder* output,
double scale) const {
{
BSONObjBuilder metadata(output->subobjStart("metadata"));
Status status = WiredTigerUtil::getApplicationMetadata(opCtx, uri(), &metadata);
if (!status.isOK()) {
metadata.append("error", "unable to retrieve metadata");
metadata.append("code", static_cast<int>(status.code()));
metadata.append("reason", status.reason());
}
}
std::string type, sourceURI;
WiredTigerUtil::fetchTypeAndSourceURI(opCtx, _uri, &type, &sourceURI);
StatusWith<std::string> metadataResult = WiredTigerUtil::getMetadata(opCtx, sourceURI);
StringData creationStringName("creationString");
if (!metadataResult.isOK()) {
BSONObjBuilder creationString(output->subobjStart(creationStringName));
creationString.append("error", "unable to retrieve creation config");
creationString.append("code", static_cast<int>(metadataResult.getStatus().code()));
creationString.append("reason", metadataResult.getStatus().reason());
} else {
output->append(creationStringName, metadataResult.getValue());
// Type can be "lsm" or "file"
output->append("type", type);
}
WiredTigerSession* session = WiredTigerRecoveryUnit::get(opCtx)->getSession(opCtx);
WT_SESSION* s = session->getSession();
Status status =
WiredTigerUtil::exportTableToBSON(s, "statistics:" + uri(), "statistics=(fast)", output);
if (!status.isOK()) {
output->append("error", "unable to retrieve statistics");
output->append("code", static_cast<int>(status.code()));
output->append("reason", status.reason());
}
return true;
}
Status WiredTigerIndex::dupKeyCheck(OperationContext* opCtx,
const BSONObj& key,
const RecordId& id) {
invariant(!hasFieldNames(key));
invariant(unique());
WiredTigerCursor curwrap(_uri, _tableId, false, opCtx);
WT_CURSOR* c = curwrap.get();
if (isDup(c, key, id))
return dupKeyError(key);
return Status::OK();
}
bool WiredTigerIndex::isEmpty(OperationContext* opCtx) {
WiredTigerCursor curwrap(_uri, _tableId, false, opCtx);
WT_CURSOR* c = curwrap.get();
if (!c)
return true;
int ret = WT_OP_CHECK(c->next(c));
if (ret == WT_NOTFOUND)
return true;
invariantWTOK(ret);
return false;
}
Status WiredTigerIndex::touch(OperationContext* opCtx) const {
if (WiredTigerRecoveryUnit::get(opCtx)->getSessionCache()->isEphemeral()) {
// Everything is already in memory.
return Status::OK();
}
return Status(ErrorCodes::CommandNotSupported, "this storage engine does not support touch");
}
long long WiredTigerIndex::getSpaceUsedBytes(OperationContext* opCtx) const {
auto ru = WiredTigerRecoveryUnit::get(opCtx);
WiredTigerSession* session = ru->getSession(opCtx);
if (ru->getSessionCache()->isEphemeral()) {
// For ephemeral case, use cursor statistics
const auto statsUri = "statistics:" + uri();
// Helper function to retrieve stats and check for errors
auto getStats = [&](int key) -> int64_t {
StatusWith<int64_t> result = WiredTigerUtil::getStatisticsValueAs<int64_t>(
session->getSession(), statsUri, "statistics=(fast)", key);
if (!result.isOK()) {
if (result.getStatus().code() == ErrorCodes::CursorNotFound)
return 0; // ident gone, so return 0
uassertStatusOK(result.getStatus());
}
return result.getValue();
};
auto inserts = getStats(WT_STAT_DSRC_CURSOR_INSERT);
auto removes = getStats(WT_STAT_DSRC_CURSOR_REMOVE);
auto insertBytes = getStats(WT_STAT_DSRC_CURSOR_INSERT_BYTES);
if (inserts == 0 || removes >= inserts)
return 0;
// Rough approximation of index size as average entry size times number of entries.
// May be off if key sizes change significantly over the life time of the collection,
// but is the best we can do currrently with the statistics available.
auto bytesPerEntry = (insertBytes + inserts - 1) / inserts; // round up
auto numEntries = inserts - removes;
return numEntries * bytesPerEntry;
}
return static_cast<long long>(WiredTigerUtil::getIdentSize(session->getSession(), _uri));
}
bool WiredTigerIndex::isDup(WT_CURSOR* c, const BSONObj& key, const RecordId& id) {
invariant(unique());
// First check whether the key exists.
KeyString data(keyStringVersion(), key, _ordering);
WiredTigerItem item(data.getBuffer(), data.getSize());
c->set_key(c, item.Get());
int ret = WT_OP_CHECK(c->search(c));
if (ret == WT_NOTFOUND) {
return false;
}
invariantWTOK(ret);
// If the key exists, check if we already have this id at this key. If so, we don't
// consider that to be a dup.
WT_ITEM value;
invariantWTOK(c->get_value(c, &value));
BufReader br(value.data, value.size);
while (br.remaining()) {
if (KeyString::decodeRecordId(&br) == id)
return false;
KeyString::TypeBits::fromBuffer(keyStringVersion(), &br); // Just advance the reader.
}
return true;
}
Status WiredTigerIndex::initAsEmpty(OperationContext* opCtx) {
// No-op
return Status::OK();
}
Status WiredTigerIndex::compact(OperationContext* opCtx) {
WiredTigerSessionCache* cache = WiredTigerRecoveryUnit::get(opCtx)->getSessionCache();
if (!cache->isEphemeral()) {
UniqueWiredTigerSession session = cache->getSession();
WT_SESSION* s = session->getSession();
int ret = s->compact(s, uri().c_str(), "timeout=0");
invariantWTOK(ret);
}
return Status::OK();
}
/**
* Base class for WiredTigerIndex bulk builders.
*
* Manages the bulk cursor used by bulk builders.
*/
class WiredTigerIndex::BulkBuilder : public SortedDataBuilderInterface {
public:
BulkBuilder(WiredTigerIndex* idx, OperationContext* opCtx)
: _ordering(idx->_ordering),
_opCtx(opCtx),
_session(WiredTigerRecoveryUnit::get(_opCtx)->getSessionCache()->getSession()),
_cursor(openBulkCursor(idx)) {}
~BulkBuilder() {
_cursor->close(_cursor);
}
protected:
WT_CURSOR* openBulkCursor(WiredTigerIndex* idx) {
// Open cursors can cause bulk open_cursor to fail with EBUSY.
// TODO any other cases that could cause EBUSY?
WiredTigerSession* outerSession = WiredTigerRecoveryUnit::get(_opCtx)->getSession(_opCtx);
outerSession->closeAllCursors();
// Not using cursor cache since we need to set "bulk".
WT_CURSOR* cursor;
// Use a different session to ensure we don't hijack an existing transaction.
// Configure the bulk cursor open to fail quickly if it would wait on a checkpoint
// completing - since checkpoints can take a long time, and waiting can result in
// an unexpected pause in building an index.
WT_SESSION* session = _session->getSession();
int err = session->open_cursor(
session, idx->uri().c_str(), NULL, "bulk,checkpoint_wait=false", &cursor);
if (!err)
return cursor;
warning() << "failed to create WiredTiger bulk cursor: " << wiredtiger_strerror(err);
warning() << "falling back to non-bulk cursor for index " << idx->uri();
invariantWTOK(session->open_cursor(session, idx->uri().c_str(), NULL, NULL, &cursor));
return cursor;
}
const Ordering _ordering;
OperationContext* const _opCtx;
UniqueWiredTigerSession const _session;
WT_CURSOR* const _cursor;
};
/**
* Bulk builds a non-unique index.
*/
class WiredTigerIndex::StandardBulkBuilder : public BulkBuilder {
public:
StandardBulkBuilder(WiredTigerIndex* idx, OperationContext* opCtx)
: BulkBuilder(idx, opCtx), _idx(idx) {}
Status addKey(const BSONObj& key, const RecordId& id) {
{
const Status s = checkKeySize(key);
if (!s.isOK())
return s;
}
KeyString data(_idx->keyStringVersion(), key, _idx->_ordering, id);
// Can't use WiredTigerCursor since we aren't using the cache.
WiredTigerItem item(data.getBuffer(), data.getSize());
_cursor->set_key(_cursor, item.Get());
WiredTigerItem valueItem = data.getTypeBits().isAllZeros()
? emptyItem
: WiredTigerItem(data.getTypeBits().getBuffer(), data.getTypeBits().getSize());
_cursor->set_value(_cursor, valueItem.Get());
invariantWTOK(_cursor->insert(_cursor));
return Status::OK();
}
void commit(bool mayInterrupt) {
// TODO do we still need this?
// this is bizarre, but required as part of the contract
WriteUnitOfWork uow(_opCtx);
uow.commit();
}
private:
WiredTigerIndex* _idx;
};
/**
* Bulk builds a unique index.
*
* In order to support unique indexes in dupsAllowed mode this class only does an actual insert
* after it sees a key after the one we are trying to insert. This allows us to gather up all
* duplicate ids and insert them all together. This is necessary since bulk cursors can only
* append data.
*/
class WiredTigerIndex::UniqueBulkBuilder : public BulkBuilder {
public:
UniqueBulkBuilder(WiredTigerIndex* idx, OperationContext* opCtx, bool dupsAllowed)
: BulkBuilder(idx, opCtx),
_idx(idx),
_dupsAllowed(dupsAllowed),
_keyString(idx->keyStringVersion()) {}
Status addKey(const BSONObj& newKey, const RecordId& id) {
{
const Status s = checkKeySize(newKey);
if (!s.isOK())
return s;
}
const int cmp = newKey.woCompare(_key, _ordering);
if (cmp != 0) {
if (!_key.isEmpty()) { // _key.isEmpty() is only true on the first call to addKey().
invariant(cmp > 0); // newKey must be > the last key
// We are done with dups of the last key so we can insert it now.
doInsert();
}
invariant(_records.empty());
} else {
// Dup found!
if (!_dupsAllowed) {
return _idx->dupKeyError(newKey);
}
// If we get here, we are in the weird mode where dups are allowed on a unique
// index, so add ourselves to the list of duplicate ids. This also replaces the
// _key which is correct since any dups seen later are likely to be newer.
}
_key = newKey.getOwned();
_keyString.resetToKey(_key, _idx->ordering());
_records.push_back(std::make_pair(id, _keyString.getTypeBits()));
return Status::OK();
}
void commit(bool mayInterrupt) {
WriteUnitOfWork uow(_opCtx);
if (!_records.empty()) {
// This handles inserting the last unique key.
doInsert();
}
uow.commit();
}
private:
void doInsert() {
invariant(!_records.empty());
KeyString value(_idx->keyStringVersion());
for (size_t i = 0; i < _records.size(); i++) {
value.appendRecordId(_records[i].first);
// When there is only one record, we can omit AllZeros TypeBits. Otherwise they need
// to be included.
if (!(_records[i].second.isAllZeros() && _records.size() == 1)) {
value.appendTypeBits(_records[i].second);
}
}
WiredTigerItem keyItem(_keyString.getBuffer(), _keyString.getSize());
WiredTigerItem valueItem(value.getBuffer(), value.getSize());
_cursor->set_key(_cursor, keyItem.Get());
_cursor->set_value(_cursor, valueItem.Get());
invariantWTOK(_cursor->insert(_cursor));
_records.clear();
}
WiredTigerIndex* _idx;
const bool _dupsAllowed;
BSONObj _key;
KeyString _keyString;
std::vector<std::pair<RecordId, KeyString::TypeBits>> _records;
};
namespace {
/**
* Implements the basic WT_CURSOR functionality used by both unique and standard indexes.
*/
class WiredTigerIndexCursorBase : public SortedDataInterface::Cursor {
public:
WiredTigerIndexCursorBase(const WiredTigerIndex& idx, OperationContext* opCtx, bool forward)
: _opCtx(opCtx),
_idx(idx),
_forward(forward),
_key(idx.keyStringVersion()),
_typeBits(idx.keyStringVersion()),
_query(idx.keyStringVersion()) {
_cursor.emplace(_idx.uri(), _idx.tableId(), false, _opCtx);
}
boost::optional<IndexKeyEntry> next(RequestedInfo parts) override {
// Advance on a cursor at the end is a no-op
if (_eof)
return {};
if (!_lastMoveWasRestore)
advanceWTCursor();
updatePosition(true);
return curr(parts);
}
void setEndPosition(const BSONObj& key, bool inclusive) override {
TRACE_CURSOR << "setEndPosition inclusive: " << inclusive << ' ' << key;
if (key.isEmpty()) {
// This means scan to end of index.
_endPosition.reset();
return;
}
// NOTE: this uses the opposite rules as a normal seek because a forward scan should
// end after the key if inclusive and before if exclusive.
const auto discriminator =
_forward == inclusive ? KeyString::kExclusiveAfter : KeyString::kExclusiveBefore;
_endPosition = stdx::make_unique<KeyString>(_idx.keyStringVersion());
_endPosition->resetToKey(stripFieldNames(key), _idx.ordering(), discriminator);
}
boost::optional<IndexKeyEntry> seek(const BSONObj& key,
bool inclusive,
RequestedInfo parts) override {
const BSONObj finalKey = stripFieldNames(key);
const auto discriminator =
_forward == inclusive ? KeyString::kExclusiveBefore : KeyString::kExclusiveAfter;
// By using a discriminator other than kInclusive, there is no need to distinguish
// unique vs non-unique key formats since both start with the key.
_query.resetToKey(finalKey, _idx.ordering(), discriminator);
seekWTCursor(_query);
updatePosition();
return curr(parts);
}
boost::optional<IndexKeyEntry> seek(const IndexSeekPoint& seekPoint,
RequestedInfo parts) override {
// TODO: don't go to a bson obj then to a KeyString, go straight
BSONObj key = IndexEntryComparison::makeQueryObject(seekPoint, _forward);
// makeQueryObject handles the discriminator in the real exclusive cases.
const auto discriminator =
_forward ? KeyString::kExclusiveBefore : KeyString::kExclusiveAfter;
_query.resetToKey(key, _idx.ordering(), discriminator);
seekWTCursor(_query);
updatePosition();
return curr(parts);
}
void save() override {
try {
if (_cursor)
_cursor->reset();
} catch (const WriteConflictException& wce) {
// Ignore since this is only called when we are about to kill our transaction
// anyway.
}
// Our saved position is wherever we were when we last called updatePosition().
// Any partially completed repositions should not effect our saved position.
}
void saveUnpositioned() override {
save();
_eof = true;
}
void restore() override {
if (!_cursor) {
_cursor.emplace(_idx.uri(), _idx.tableId(), false, _opCtx);
}
// Ensure an active session exists, so any restored cursors will bind to it
invariant(WiredTigerRecoveryUnit::get(_opCtx)->getSession(_opCtx) == _cursor->getSession());
if (!_eof) {
// Unique indices *don't* include the record id in their KeyStrings. If we seek to the
// same key with a new record id, seeking will successfully find the key and will return
// true. This will cause us to skip the key with the new record id, since we set
// _lastMoveWasRestore to false.
//
// Standard (non-unique) indices *do* include the record id in their KeyStrings. This
// means that restoring to the same key with a new record id will return false, and we
// will *not* skip the key with the new record id.
_lastMoveWasRestore = !seekWTCursor(_key);
TRACE_CURSOR << "restore _lastMoveWasRestore:" << _lastMoveWasRestore;
}
}
void detachFromOperationContext() final {
_opCtx = nullptr;
_cursor = boost::none;
}
void reattachToOperationContext(OperationContext* opCtx) final {
_opCtx = opCtx;
// _cursor recreated in restore() to avoid risk of WT_ROLLBACK issues.
}
protected:
// Called after _key has been filled in. Must not throw WriteConflictException.
virtual void updateIdAndTypeBits() = 0;
boost::optional<IndexKeyEntry> curr(RequestedInfo parts) const {
if (_eof)
return {};
dassert(!atOrPastEndPointAfterSeeking());
dassert(!_id.isNull());
BSONObj bson;
if (TRACING_ENABLED || (parts & kWantKey)) {
bson = KeyString::toBson(_key.getBuffer(), _key.getSize(), _idx.ordering(), _typeBits);
TRACE_CURSOR << " returning " << bson << ' ' << _id;
}
return {{std::move(bson), _id}};
}
bool atOrPastEndPointAfterSeeking() const {
if (_eof)
return true;
if (!_endPosition)
return false;
const int cmp = _key.compare(*_endPosition);
// We set up _endPosition to be in between the last in-range value and the first
// out-of-range value. In particular, it is constructed to never equal any legal index
// key.
dassert(cmp != 0);
if (_forward) {
// We may have landed after the end point.
return cmp > 0;
} else {
// We may have landed before the end point.
return cmp < 0;
}
}
void advanceWTCursor() {
WT_CURSOR* c = _cursor->get();
int ret = WT_OP_CHECK(_forward ? c->next(c) : c->prev(c));
if (ret == WT_NOTFOUND) {
_cursorAtEof = true;
return;
}
invariantWTOK(ret);
_cursorAtEof = false;
}
// Seeks to query. Returns true on exact match.
bool seekWTCursor(const KeyString& query) {
WT_CURSOR* c = _cursor->get();
int cmp = -1;
const WiredTigerItem keyItem(query.getBuffer(), query.getSize());
c->set_key(c, keyItem.Get());
int ret = WT_OP_CHECK(c->search_near(c, &cmp));
if (ret == WT_NOTFOUND) {
_cursorAtEof = true;
TRACE_CURSOR << "\t not found";
return false;
}
invariantWTOK(ret);
_cursorAtEof = false;
TRACE_CURSOR << "\t cmp: " << cmp;
if (cmp == 0) {
// Found it!
return true;
}
// Make sure we land on a matching key (after/before for forward/reverse).
if (_forward ? cmp < 0 : cmp > 0) {
advanceWTCursor();
}
return false;
}
/**
* This must be called after moving the cursor to update our cached position. It should not
* be called after a restore that did not restore to original state since that does not
* logically move the cursor until the following call to next().
*/
void updatePosition(bool inNext = false) {
_lastMoveWasRestore = false;
if (_cursorAtEof) {
_eof = true;
_id = RecordId();
return;
}
_eof = false;
WT_CURSOR* c = _cursor->get();
WT_ITEM item;
invariantWTOK(c->get_key(c, &item));
const auto isForwardNextCall = _forward && inNext && !_key.isEmpty();
if (isForwardNextCall) {
// Due to a bug in wired tiger (SERVER-21867) sometimes calling next
// returns something prev.
const int cmp =
std::memcmp(_key.getBuffer(), item.data, std::min(_key.getSize(), item.size));
bool nextNotIncreasing = cmp > 0 || (cmp == 0 && _key.getSize() > item.size);
if (MONGO_FAIL_POINT(WTEmulateOutOfOrderNextIndexKey)) {
log() << "WTIndex::updatePosition simulating next key not increasing.";
nextNotIncreasing = true;
}
if (nextNotIncreasing) {
// Our new key is less than the old key which means the next call moved to !next.
log() << "WTIndex::updatePosition -- the new key ( "
<< redact(toHex(item.data, item.size)) << ") is less than the previous key ("
<< redact(_key.toString()) << "), which is a bug.";
// Force a retry of the operation from our last known position by acting as-if
// we received a WT_ROLLBACK error.
throw WriteConflictException();
}
}
// Store (a copy of) the new item data as the current key for this cursor.
_key.resetFromBuffer(item.data, item.size);
if (atOrPastEndPointAfterSeeking()) {
_eof = true;
return;
}
updateIdAndTypeBits();
}
OperationContext* _opCtx;
boost::optional<WiredTigerCursor> _cursor;
const WiredTigerIndex& _idx; // not owned
const bool _forward;
// These are where this cursor instance is. They are not changed in the face of a failing
// next().
KeyString _key;
KeyString::TypeBits _typeBits;
RecordId _id;
bool _eof = true;
// This differs from _eof in that it always reflects the result of the most recent call to
// reposition _cursor.
bool _cursorAtEof = false;
// Used by next to decide to return current position rather than moving. Should be reset to
// false by any operation that moves the cursor, other than subsequent save/restore pairs.
bool _lastMoveWasRestore = false;
KeyString _query;
std::unique_ptr<KeyString> _endPosition;
};
class WiredTigerIndexStandardCursor final : public WiredTigerIndexCursorBase {
public:
WiredTigerIndexStandardCursor(const WiredTigerIndex& idx, OperationContext* opCtx, bool forward)
: WiredTigerIndexCursorBase(idx, opCtx, forward) {}
void updateIdAndTypeBits() override {
_id = KeyString::decodeRecordIdAtEnd(_key.getBuffer(), _key.getSize());
WT_CURSOR* c = _cursor->get();
WT_ITEM item;
invariantWTOK(c->get_value(c, &item));
BufReader br(item.data, item.size);
_typeBits.resetFromBuffer(&br);
}
};
class WiredTigerIndexUniqueCursor final : public WiredTigerIndexCursorBase {
public:
WiredTigerIndexUniqueCursor(const WiredTigerIndex& idx, OperationContext* opCtx, bool forward)
: WiredTigerIndexCursorBase(idx, opCtx, forward) {}
void updateIdAndTypeBits() override {
// We assume that cursors can only ever see unique indexes in their "pristine" state,
// where no duplicates are possible. The cases where dups are allowed should hold
// sufficient locks to ensure that no cursor ever sees them.
WT_CURSOR* c = _cursor->get();
WT_ITEM item;
invariantWTOK(c->get_value(c, &item));
BufReader br(item.data, item.size);
_id = KeyString::decodeRecordId(&br);
_typeBits.resetFromBuffer(&br);
if (!br.atEof()) {
severe() << "Unique index cursor seeing multiple records for key "
<< redact(curr(kWantKey)->key) << " in index " << _idx.indexName();
fassertFailed(28608);
}
}
boost::optional<IndexKeyEntry> seekExact(const BSONObj& key, RequestedInfo parts) override {
_query.resetToKey(stripFieldNames(key), _idx.ordering());
const WiredTigerItem keyItem(_query.getBuffer(), _query.getSize());
WT_CURSOR* c = _cursor->get();
c->set_key(c, keyItem.Get());
// Using search rather than search_near.
int ret = WT_OP_CHECK(c->search(c));
if (ret != WT_NOTFOUND)
invariantWTOK(ret);
_cursorAtEof = ret == WT_NOTFOUND;
updatePosition();
dassert(_eof || _key.compare(_query) == 0);
return curr(parts);
}
};
} // namespace
WiredTigerIndexUnique::WiredTigerIndexUnique(OperationContext* ctx,
const std::string& uri,
const IndexDescriptor* desc)
: WiredTigerIndex(ctx, uri, desc) {}
std::unique_ptr<SortedDataInterface::Cursor> WiredTigerIndexUnique::newCursor(
OperationContext* opCtx, bool forward) const {
return stdx::make_unique<WiredTigerIndexUniqueCursor>(*this, opCtx, forward);
}
SortedDataBuilderInterface* WiredTigerIndexUnique::getBulkBuilder(OperationContext* opCtx,
bool dupsAllowed) {
return new UniqueBulkBuilder(this, opCtx, dupsAllowed);
}
Status WiredTigerIndexUnique::_insert(WT_CURSOR* c,
const BSONObj& key,
const RecordId& id,
bool dupsAllowed) {
const KeyString data(keyStringVersion(), key, _ordering);
WiredTigerItem keyItem(data.getBuffer(), data.getSize());
KeyString value(keyStringVersion(), id);
if (!data.getTypeBits().isAllZeros())
value.appendTypeBits(data.getTypeBits());
WiredTigerItem valueItem(value.getBuffer(), value.getSize());
c->set_key(c, keyItem.Get());
c->set_value(c, valueItem.Get());
int ret = WT_OP_CHECK(c->insert(c));
if (ret != WT_DUPLICATE_KEY) {
return wtRCToStatus(ret);
}
// we might be in weird mode where there might be multiple values
// we put them all in the "list"
// Note that we can't omit AllZeros when there are multiple ids for a value. When we remove
// down to a single value, it will be cleaned up.
ret = WT_OP_CHECK(c->search(c));
invariantWTOK(ret);
WT_ITEM old;
invariantWTOK(c->get_value(c, &old));
bool insertedId = false;
value.resetToEmpty();
BufReader br(old.data, old.size);
while (br.remaining()) {
RecordId idInIndex = KeyString::decodeRecordId(&br);
if (id == idInIndex)
return Status::OK(); // already in index
if (!insertedId && id < idInIndex) {
value.appendRecordId(id);
value.appendTypeBits(data.getTypeBits());
insertedId = true;
}
// Copy from old to new value
value.appendRecordId(idInIndex);
value.appendTypeBits(KeyString::TypeBits::fromBuffer(keyStringVersion(), &br));
}
if (!dupsAllowed)
return dupKeyError(key);
if (!insertedId) {
// This id is higher than all currently in the index for this key
value.appendRecordId(id);
value.appendTypeBits(data.getTypeBits());
}
valueItem = WiredTigerItem(value.getBuffer(), value.getSize());
c->set_value(c, valueItem.Get());
return wtRCToStatus(c->update(c));
}
void WiredTigerIndexUnique::_unindex(WT_CURSOR* c,
const BSONObj& key,
const RecordId& id,
bool dupsAllowed) {
KeyString data(keyStringVersion(), key, _ordering);
WiredTigerItem keyItem(data.getBuffer(), data.getSize());
c->set_key(c, keyItem.Get());
if (!dupsAllowed) {
// nice and clear
int ret = WT_OP_CHECK(c->remove(c));
if (ret == WT_NOTFOUND) {
return;
}
invariantWTOK(ret);
return;
}
// dups are allowed, so we have to deal with a vector of RecordIds.
int ret = WT_OP_CHECK(c->search(c));
if (ret == WT_NOTFOUND) {
// WT_NOTFOUND is only expected during a background index build. Insert a dummy value and
// delete it again to trigger a write conflict in case this is being concurrently indexed by
// the background indexer.
c->set_key(c, keyItem.Get());
c->set_value(c, emptyItem.Get());
invariantWTOK(WT_OP_CHECK(c->insert(c)));
c->set_key(c, keyItem.Get());
invariantWTOK(WT_OP_CHECK(c->remove(c)));
return;
}
invariantWTOK(ret);
WT_ITEM old;
invariantWTOK(c->get_value(c, &old));
bool foundId = false;
std::vector<std::pair<RecordId, KeyString::TypeBits>> records;
BufReader br(old.data, old.size);
while (br.remaining()) {
RecordId idInIndex = KeyString::decodeRecordId(&br);
KeyString::TypeBits typeBits = KeyString::TypeBits::fromBuffer(keyStringVersion(), &br);
if (id == idInIndex) {
if (records.empty() && !br.remaining()) {
// This is the common case: we are removing the only id for this key.
// Remove the whole entry.
invariantWTOK(WT_OP_CHECK(c->remove(c)));
return;
}
foundId = true;
continue;
}
records.push_back(std::make_pair(idInIndex, typeBits));
}
if (!foundId) {
warning().stream() << id << " not found in the index for key " << redact(key);
return; // nothing to do
}
// Put other ids for this key back in the index.
KeyString newValue(keyStringVersion());
invariant(!records.empty());
for (size_t i = 0; i < records.size(); i++) {
newValue.appendRecordId(records[i].first);
// When there is only one record, we can omit AllZeros TypeBits. Otherwise they need
// to be included.
if (!(records[i].second.isAllZeros() && records.size() == 1)) {
newValue.appendTypeBits(records[i].second);
}
}
WiredTigerItem valueItem = WiredTigerItem(newValue.getBuffer(), newValue.getSize());
c->set_value(c, valueItem.Get());
invariantWTOK(c->update(c));
}
// ------------------------------
WiredTigerIndexStandard::WiredTigerIndexStandard(OperationContext* ctx,
const std::string& uri,
const IndexDescriptor* desc)
: WiredTigerIndex(ctx, uri, desc) {}
std::unique_ptr<SortedDataInterface::Cursor> WiredTigerIndexStandard::newCursor(
OperationContext* opCtx, bool forward) const {
return stdx::make_unique<WiredTigerIndexStandardCursor>(*this, opCtx, forward);
}
SortedDataBuilderInterface* WiredTigerIndexStandard::getBulkBuilder(OperationContext* opCtx,
bool dupsAllowed) {
// We aren't unique so dups better be allowed.
invariant(dupsAllowed);
return new StandardBulkBuilder(this, opCtx);
}
Status WiredTigerIndexStandard::_insert(WT_CURSOR* c,
const BSONObj& keyBson,
const RecordId& id,
bool dupsAllowed) {
invariant(dupsAllowed);
TRACE_INDEX << " key: " << keyBson << " id: " << id;
KeyString key(keyStringVersion(), keyBson, _ordering, id);
WiredTigerItem keyItem(key.getBuffer(), key.getSize());
WiredTigerItem valueItem = key.getTypeBits().isAllZeros()
? emptyItem
: WiredTigerItem(key.getTypeBits().getBuffer(), key.getTypeBits().getSize());
c->set_key(c, keyItem.Get());
c->set_value(c, valueItem.Get());
int ret = WT_OP_CHECK(c->insert(c));
if (ret != WT_DUPLICATE_KEY)
return wtRCToStatus(ret);
// If the record was already in the index, we just return OK.
// This can happen, for example, when building a background index while documents are being
// written and reindexed.
return Status::OK();
}
void WiredTigerIndexStandard::_unindex(WT_CURSOR* c,
const BSONObj& key,
const RecordId& id,
bool dupsAllowed) {
invariant(dupsAllowed);
KeyString data(keyStringVersion(), key, _ordering, id);
WiredTigerItem item(data.getBuffer(), data.getSize());
c->set_key(c, item.Get());
int ret = WT_OP_CHECK(c->remove(c));
if (ret != WT_NOTFOUND) {
invariantWTOK(ret);
} else {
// WT_NOTFOUND is only expected during a background index build. Insert a dummy value and
// delete it again to trigger a write conflict in case this is being concurrently indexed by
// the background indexer.
c->set_key(c, item.Get());
c->set_value(c, emptyItem.Get());
invariantWTOK(WT_OP_CHECK(c->insert(c)));
c->set_key(c, item.Get());
invariantWTOK(WT_OP_CHECK(c->remove(c)));
}
}
// ---------------- for compatability with rc4 and previous ------
int index_collator_customize(WT_COLLATOR* coll,
WT_SESSION* s,
const char* uri,
WT_CONFIG_ITEM* metadata,
WT_COLLATOR** collp) {
fassertFailedWithStatusNoTrace(28580,
Status(ErrorCodes::UnsupportedFormat,
str::stream()
<< "Found an index from an unsupported RC version."
<< " Please restart with --repair to fix."));
}
extern "C" MONGO_COMPILER_API_EXPORT int index_collator_extension(WT_CONNECTION* conn,
WT_CONFIG_ARG* cfg) {
static WT_COLLATOR idx_static;
idx_static.customize = index_collator_customize;
return conn->add_collator(conn, "mongo_index", &idx_static, NULL);
}
} // namespace mongo
|