aboutsummaryrefslogtreecommitdiff
path: root/src/blockchain_utilities/blockchain_blackball.cpp
blob: 8b007e901598204790104f2a09b41d1a04d2680b (plain) (blame)
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
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
// Copyright (c) 2014-2018, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
//
// 2. 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.
//
// 3. Neither the name of the copyright holder 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 HOLDER 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.

#include <boost/range/adaptor/transformed.hpp>
#include <boost/algorithm/string.hpp>
#include <boost/archive/portable_binary_iarchive.hpp>
#include <boost/archive/portable_binary_oarchive.hpp>
#include "common/unordered_containers_boost_serialization.h"
#include "common/command_line.h"
#include "common/varint.h"
#include "serialization/crypto.h"
#include "cryptonote_basic/cryptonote_boost_serialization.h"
#include "cryptonote_core/tx_pool.h"
#include "cryptonote_core/cryptonote_core.h"
#include "cryptonote_core/blockchain.h"
#include "blockchain_db/blockchain_db.h"
#include "blockchain_db/db_types.h"
#include "wallet/ringdb.h"
#include "version.h"

#undef MONERO_DEFAULT_LOG_CATEGORY
#define MONERO_DEFAULT_LOG_CATEGORY "bcutil"

namespace po = boost::program_options;
using namespace epee;
using namespace cryptonote;

static const char zerokey[8] = {0};
static const MDB_val zerokval = { sizeof(zerokey), (void *)zerokey };

static uint64_t records_per_sync = 200;
static uint64_t db_flags = 0;
static MDB_dbi dbi_relative_rings;
static MDB_dbi dbi_outputs;
static MDB_dbi dbi_processed_txidx;
static MDB_dbi dbi_spent;
static MDB_dbi dbi_per_amount;
static MDB_dbi dbi_ring_instances;
static MDB_dbi dbi_stats;
static MDB_env *env = NULL;

struct output_data
{
  uint64_t amount;
  uint64_t offset;
  output_data(): amount(0), offset(0) {}
  output_data(uint64_t a, uint64_t i): amount(a), offset(i) {}
  bool operator==(const output_data &other) const { return other.amount == amount && other.offset == offset; }
};

//
// relative_rings: key_image -> vector<uint64_t>
// outputs: 128 bits -> set of key images
// processed_txidx: string -> uint64_t
// spent: amount -> offset
// ring_instances: vector<uint64_t> -> uint64_t
// stats: string -> arbitrary
//

static bool parse_db_sync_mode(std::string db_sync_mode)
{
  std::vector<std::string> options;
  boost::trim(db_sync_mode);
  boost::split(options, db_sync_mode, boost::is_any_of(" :"));

  for(const auto &option : options)
    MDEBUG("option: " << option);

  // default to fast:async:1
  uint64_t DEFAULT_FLAGS = DBF_FAST;

  if(options.size() == 0)
  {
    // default to fast:async:1
    db_flags = DEFAULT_FLAGS;
  }

  bool safemode = false;
  if(options.size() >= 1)
  {
    if(options[0] == "safe")
    {
      safemode = true;
      db_flags = DBF_SAFE;
    }
    else if(options[0] == "fast")
    {
      db_flags = DBF_FAST;
    }
    else if(options[0] == "fastest")
    {
      db_flags = DBF_FASTEST;
      records_per_sync = 1000; // default to fastest:async:1000
    }
    else
      db_flags = DEFAULT_FLAGS;
  }

  if(options.size() >= 2 && !safemode)
  {
    char *endptr;
    uint64_t bps = strtoull(options[1].c_str(), &endptr, 0);
    if (*endptr == '\0')
      records_per_sync = bps;
  }

  return true;
}

static std::string get_default_db_path()
{
  boost::filesystem::path dir = tools::get_default_data_dir();
  // remove .bitmonero, replace with .shared-ringdb
  dir = dir.remove_filename();
  dir /= ".shared-ringdb";
  return dir.string();
}

static std::string get_cache_filename(boost::filesystem::path filename)
{
  if (!boost::filesystem::is_directory(filename))
    filename.remove_filename();
  return filename.string();
}

static int compare_hash32(const MDB_val *a, const MDB_val *b)
{
  const uint32_t *va = (const uint32_t*) a->mv_data;
  const uint32_t *vb = (const uint32_t*) b->mv_data;
  for (int n = 7; n >= 0; n--)
  {
    if (va[n] == vb[n])
      continue;
    return va[n] < vb[n] ? -1 : 1;
  }

  return 0;
}

int compare_uint64(const MDB_val *a, const MDB_val *b)
{
  const uint64_t va = *(const uint64_t *)a->mv_data;
  const uint64_t vb = *(const uint64_t *)b->mv_data;
  return (va < vb) ? -1 : va > vb;
}

static int compare_double64(const MDB_val *a, const MDB_val *b)
{
  const uint64_t va = *(const uint64_t*) a->mv_data;
  const uint64_t vb = *(const uint64_t*) b->mv_data;
  if (va == vb)
  {
    const uint64_t va = ((const uint64_t*) a->mv_data)[1];
    const uint64_t vb = ((const uint64_t*) b->mv_data)[1];
    return va < vb ? -1 : va > vb;
  }
  return va < vb ? -1 : va > vb;
}

static int resize_env(const char *db_path)
{
  MDB_envinfo mei;
  MDB_stat mst;
  int ret;

  size_t needed = 1000ul * 1024 * 1024; // at least 1000 MB

  ret = mdb_env_info(env, &mei);
  if (ret)
    return ret;
  ret = mdb_env_stat(env, &mst);
  if (ret)
    return ret;
  uint64_t size_used = mst.ms_psize * mei.me_last_pgno;
  uint64_t mapsize = mei.me_mapsize;
  if (size_used + needed > mei.me_mapsize)
  {
    try
    {
      boost::filesystem::path path(db_path);
      boost::filesystem::space_info si = boost::filesystem::space(path);
      if(si.available < needed)
      {
        MERROR("!! WARNING: Insufficient free space to extend database !!: " << (si.available >> 20L) << " MB available");
        return ENOSPC;
      }
    }
    catch(...)
    {
      // print something but proceed.
      MWARNING("Unable to query free disk space.");
    }

    mapsize += needed;
  }
  return mdb_env_set_mapsize(env, mapsize);
}

static void init(std::string cache_filename)
{
  MDB_txn *txn;
  bool tx_active = false;
  int dbr;

  MINFO("Creating spent output cache in " << cache_filename);

  tools::create_directories_if_necessary(cache_filename);

  int flags = 0;
  if (db_flags & DBF_FAST)
    flags |= MDB_NOSYNC;
  if (db_flags & DBF_FASTEST)
    flags |= MDB_NOSYNC | MDB_WRITEMAP | MDB_MAPASYNC;

  dbr = mdb_env_create(&env);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LDMB environment: " + std::string(mdb_strerror(dbr)));
  dbr = mdb_env_set_maxdbs(env, 7);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to set max env dbs: " + std::string(mdb_strerror(dbr)));
  const std::string actual_filename = get_cache_filename(cache_filename); 
  dbr = mdb_env_open(env, actual_filename.c_str(), flags, 0664);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open rings database file '"
      + actual_filename + "': " + std::string(mdb_strerror(dbr)));

  dbr = mdb_txn_begin(env, NULL, 0, &txn);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
  epee::misc_utils::auto_scope_leave_caller txn_dtor = epee::misc_utils::create_scope_leave_handler([&](){if (tx_active) mdb_txn_abort(txn);});
  tx_active = true;

  dbr = mdb_dbi_open(txn, "relative_rings", MDB_CREATE | MDB_INTEGERKEY, &dbi_relative_rings);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
  mdb_set_compare(txn, dbi_relative_rings, compare_hash32);

  dbr = mdb_dbi_open(txn, "outputs", MDB_CREATE | MDB_INTEGERKEY, &dbi_outputs);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
  mdb_set_compare(txn, dbi_outputs, compare_double64);

  dbr = mdb_dbi_open(txn, "processed_txidx", MDB_CREATE, &dbi_processed_txidx);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));

  dbr = mdb_dbi_open(txn, "spent", MDB_CREATE | MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED, &dbi_spent);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
  mdb_set_dupsort(txn, dbi_spent, compare_uint64);

  dbr = mdb_dbi_open(txn, "per_amount", MDB_CREATE | MDB_INTEGERKEY, &dbi_per_amount);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
  mdb_set_compare(txn, dbi_per_amount, compare_uint64);

  dbr = mdb_dbi_open(txn, "ring_instances", MDB_CREATE, &dbi_ring_instances);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));

  dbr = mdb_dbi_open(txn, "stats", MDB_CREATE, &dbi_stats);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));

  dbr = mdb_txn_commit(txn);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
  tx_active = false;
}

static void close()
{
  if (env)
  {
    mdb_dbi_close(env, dbi_relative_rings);
    mdb_dbi_close(env, dbi_outputs);
    mdb_dbi_close(env, dbi_processed_txidx);
    mdb_dbi_close(env, dbi_per_amount);
    mdb_dbi_close(env, dbi_spent);
    mdb_dbi_close(env, dbi_ring_instances);
    mdb_dbi_close(env, dbi_stats);
    mdb_env_close(env);
    env = NULL;
  }
}

static std::string compress_ring(const std::vector<uint64_t> &ring, std::string s = "")
{
  const size_t sz = s.size();
  s.resize(s.size() + 12 * ring.size());
  char *ptr = (char*)s.data() + sz;
  for (uint64_t out: ring)
    tools::write_varint(ptr, out);
  if (ptr > s.data() + sz + 12 * ring.size())
    throw std::runtime_error("varint output overflow");
  s.resize(ptr - s.data());
  return s;
}

static std::string compress_ring(uint64_t amount, const std::vector<uint64_t> &ring)
{
  char s[12], *ptr = s;
  tools::write_varint(ptr, amount);
  if (ptr > s + sizeof(s))
    throw std::runtime_error("varint output overflow");
  return compress_ring(ring, std::string(s, ptr-s));
}

static std::vector<uint64_t> decompress_ring(const std::string &s)
{
  std::vector<uint64_t> ring;
  int read = 0;
  for (std::string::const_iterator i = s.begin(); i != s.cend(); std::advance(i, read))
  {
    uint64_t out;
    std::string tmp(i, s.cend());
    read = tools::read_varint(tmp.begin(), tmp.end(), out);
    CHECK_AND_ASSERT_THROW_MES(read > 0 && read <= 256, "Internal error decompressing ring");
    ring.push_back(out);
  }
  return ring;
}

static bool for_all_transactions(const std::string &filename, uint64_t &start_idx, uint64_t &n_txes, const std::function<bool(const cryptonote::transaction_prefix&)> &f)
{
  MDB_env *env;
  MDB_dbi dbi;
  MDB_txn *txn;
  MDB_cursor *cur;
  int dbr;
  bool tx_active = false;
  MDB_val k;
  MDB_val v;

  dbr = mdb_env_create(&env);
  if (dbr) throw std::runtime_error("Failed to create LDMB environment: " + std::string(mdb_strerror(dbr)));
  dbr = mdb_env_set_maxdbs(env, 2);
  if (dbr) throw std::runtime_error("Failed to set max env dbs: " + std::string(mdb_strerror(dbr)));
  const std::string actual_filename = filename;
  dbr = mdb_env_open(env, actual_filename.c_str(), 0, 0664);
  if (dbr) throw std::runtime_error("Failed to open rings database file '"
      + actual_filename + "': " + std::string(mdb_strerror(dbr)));

  dbr = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
  if (dbr) throw std::runtime_error("Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
  epee::misc_utils::auto_scope_leave_caller txn_dtor = epee::misc_utils::create_scope_leave_handler([&](){if (tx_active) mdb_txn_abort(txn);});
  tx_active = true;

  dbr = mdb_dbi_open(txn, "txs_pruned", MDB_INTEGERKEY, &dbi);
  if (dbr)
    dbr = mdb_dbi_open(txn, "txs", MDB_INTEGERKEY, &dbi);
  if (dbr) throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
  dbr = mdb_cursor_open(txn, dbi, &cur);
  if (dbr) throw std::runtime_error("Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));
  MDB_stat stat;
  dbr = mdb_stat(txn, dbi, &stat);
  if (dbr) throw std::runtime_error("Failed to query m_block_info: " + std::string(mdb_strerror(dbr)));
  n_txes = stat.ms_entries;

  bool fret = true;

  k.mv_size = sizeof(uint64_t);
  k.mv_data = &start_idx;
  MDB_cursor_op op = MDB_SET;
  while (1)
  {
    int ret = mdb_cursor_get(cur, &k, &v, op);
    op = MDB_NEXT;
    if (ret == MDB_NOTFOUND)
      break;
    if (ret)
      throw std::runtime_error("Failed to enumerate transactions: " + std::string(mdb_strerror(ret)));

    if (k.mv_size != sizeof(uint64_t))
      throw std::runtime_error("Bad key size");
    const uint64_t idx = *(uint64_t*)k.mv_data;
    if (idx < start_idx)
      continue;

    cryptonote::transaction_prefix tx;
    blobdata bd;
    bd.assign(reinterpret_cast<char*>(v.mv_data), v.mv_size);
    std::stringstream ss;
    ss << bd;
    binary_archive<false> ba(ss);
    bool r = do_serialize(ba, tx);
    CHECK_AND_ASSERT_MES(r, false, "Failed to parse transaction from blob");

    start_idx = *(uint64_t*)k.mv_data;
    if (!f(tx)) {
      fret = false;
      break;
    }
  }

  mdb_cursor_close(cur);
  dbr = mdb_txn_commit(txn);
  if (dbr) throw std::runtime_error("Failed to commit db transaction: " + std::string(mdb_strerror(dbr)));
  tx_active = false;
  mdb_dbi_close(env, dbi);
  mdb_env_close(env);
  return fret;
}

static uint64_t find_first_diverging_transaction(const std::string &first_filename, const std::string &second_filename)
{
  MDB_env *env[2];
  MDB_dbi dbi[2];
  MDB_txn *txn[2];
  MDB_cursor *cur[2];
  int dbr;
  bool tx_active[2] = { false, false };
  uint64_t n_txes[2];
  MDB_val k;
  MDB_val v[2];

  epee::misc_utils::auto_scope_leave_caller txn_dtor[2];
  for (int i = 0; i < 2; ++i)
  {
    dbr = mdb_env_create(&env[i]);
    if (dbr) throw std::runtime_error("Failed to create LDMB environment: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_env_set_maxdbs(env[i], 2);
    if (dbr) throw std::runtime_error("Failed to set max env dbs: " + std::string(mdb_strerror(dbr)));
    const std::string actual_filename = i ? second_filename : first_filename;
    dbr = mdb_env_open(env[i], actual_filename.c_str(), 0, 0664);
    if (dbr) throw std::runtime_error("Failed to open rings database file '"
        + actual_filename + "': " + std::string(mdb_strerror(dbr)));

    dbr = mdb_txn_begin(env[i], NULL, MDB_RDONLY, &txn[i]);
    if (dbr) throw std::runtime_error("Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    txn_dtor[i] = epee::misc_utils::create_scope_leave_handler([&, i](){if (tx_active[i]) mdb_txn_abort(txn[i]);});
    tx_active[i] = true;

    dbr = mdb_dbi_open(txn[i], "txs_pruned", MDB_INTEGERKEY, &dbi[i]);
    if (dbr)
      dbr = mdb_dbi_open(txn[i], "txs", MDB_INTEGERKEY, &dbi[i]);
    if (dbr) throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_cursor_open(txn[i], dbi[i], &cur[i]);
    if (dbr) throw std::runtime_error("Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));
    MDB_stat stat;
    dbr = mdb_stat(txn[i], dbi[i], &stat);
    if (dbr) throw std::runtime_error("Failed to query m_block_info: " + std::string(mdb_strerror(dbr)));
    n_txes[i] = stat.ms_entries;
  }

  if (n_txes[0] == 0 || n_txes[1] == 0)
    throw std::runtime_error("No transaction in the database");
  uint64_t lo = 0, hi = std::min(n_txes[0], n_txes[1]) - 1;
  while (lo <= hi)
  {
    uint64_t mid = (lo + hi) / 2;

    k.mv_size = sizeof(uint64_t);
    k.mv_data = (void*)&mid;
    dbr = mdb_cursor_get(cur[0], &k, &v[0], MDB_SET);
    if (dbr) throw std::runtime_error("Failed to query transaction: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_cursor_get(cur[1], &k, &v[1], MDB_SET);
    if (dbr) throw std::runtime_error("Failed to query transaction: " + std::string(mdb_strerror(dbr)));
    if (v[0].mv_size == v[1].mv_size && !memcmp(v[0].mv_data, v[1].mv_data, v[0].mv_size))
      lo = mid + 1;
    else
      hi = mid - 1;
  }

  for (int i = 0; i < 2; ++i)
  {
    mdb_cursor_close(cur[i]);
    dbr = mdb_txn_commit(txn[i]);
    if (dbr) throw std::runtime_error("Failed to query transaction: " + std::string(mdb_strerror(dbr)));
    tx_active[i] = false;
    mdb_dbi_close(env[i], dbi[i]);
    mdb_env_close(env[i]);
  }
  return hi;
}

static std::vector<uint64_t> canonicalize(const std::vector<uint64_t> &v)
{
  std::vector<uint64_t> c;
  c.reserve(v.size());
  c.push_back(v[0]);
  for (size_t n = 1; n < v.size(); ++n)
  {
    if (v[n] != 0)
      c.push_back(v[n]);
  }
  if (c.size() < v.size())
  {
    MINFO("Ring has duplicate member(s): " <<
        boost::join(v | boost::adaptors::transformed([](uint64_t out){return std::to_string(out);}), " "));
  }
  return c;
}

static uint64_t get_num_spent_outputs()
{
  MDB_txn *txn;
  bool tx_active = false;

  int dbr = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
  epee::misc_utils::auto_scope_leave_caller txn_dtor = epee::misc_utils::create_scope_leave_handler([&](){if (tx_active) mdb_txn_abort(txn);});
  tx_active = true;

  MDB_cursor *cur;
  dbr = mdb_cursor_open(txn, dbi_spent, &cur);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open cursor for spent outputs: " + std::string(mdb_strerror(dbr)));
  MDB_val k, v;
  mdb_size_t count = 0, tmp;

  MDB_cursor_op op = MDB_FIRST;
  while (1)
  {
    dbr = mdb_cursor_get(cur, &k, &v, op);
    op = MDB_NEXT_NODUP;
    if (dbr == MDB_NOTFOUND)
      break;
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get first/next spent output: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_cursor_count(cur, &tmp);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to count entries: " + std::string(mdb_strerror(dbr)));
    count += tmp;
  }

  mdb_cursor_close(cur);
  dbr = mdb_txn_commit(txn);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn: " + std::string(mdb_strerror(dbr)));
  tx_active = false;

  return count;
}

static bool add_spent_output(MDB_cursor *cur, const output_data &od)
{
  MDB_val k = {sizeof(od.amount), (void*)&od.amount};
  MDB_val v = {sizeof(od.offset), (void*)&od.offset};
  int dbr = mdb_cursor_put(cur, &k, &v, MDB_NODUPDATA);
  if (dbr == MDB_KEYEXIST)
    return false;
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to add spent output: " + std::string(mdb_strerror(dbr)));
  return true;
}

static bool is_output_spent(MDB_cursor *cur, const output_data &od)
{
  MDB_val k = {sizeof(od.amount), (void*)&od.amount};
  MDB_val v = {sizeof(od.offset), (void*)&od.offset};
  int dbr = mdb_cursor_get(cur, &k, &v, MDB_GET_BOTH);
  CHECK_AND_ASSERT_THROW_MES(!dbr || dbr == MDB_NOTFOUND, "Failed to get spent output: " + std::string(mdb_strerror(dbr)));
  bool spent = dbr == 0;
  return spent;
}

static std::vector<output_data> get_spent_outputs(MDB_txn *txn)
{
  MDB_cursor *cur;
  int dbr = mdb_cursor_open(txn, dbi_spent, &cur);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open cursor for spent outputs: " + std::string(mdb_strerror(dbr)));
  MDB_val k, v;
  mdb_size_t count = 0;
  dbr = mdb_cursor_get(cur, &k, &v, MDB_FIRST);
  if (dbr != MDB_NOTFOUND)
  {
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get first spent output: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_cursor_count(cur, &count);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to count entries: " + std::string(mdb_strerror(dbr)));
  }
  std::vector<output_data> outs;
  outs.reserve(count);
  while (1)
  {
    outs.push_back({*(const uint64_t*)k.mv_data, *(const uint64_t*)v.mv_data});
    dbr = mdb_cursor_get(cur, &k, &v, MDB_NEXT);
    if (dbr == MDB_NOTFOUND)
      break;
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get next spent output: " + std::string(mdb_strerror(dbr)));
  }
  mdb_cursor_close(cur);
  return outs;
}

static void get_per_amount_outputs(MDB_txn *txn, uint64_t amount, uint64_t &total, uint64_t &spent)
{
  MDB_cursor *cur;
  int dbr = mdb_cursor_open(txn, dbi_per_amount, &cur);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open cursor for per amount outputs: " + std::string(mdb_strerror(dbr)));
  MDB_val k, v;
  mdb_size_t count = 0;
  k.mv_size = sizeof(uint64_t);
  k.mv_data = (void*)&amount;
  dbr = mdb_cursor_get(cur, &k, &v, MDB_SET);
  if (dbr == MDB_NOTFOUND)
  {
    total = spent = 0;
  }
  else
  {
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get per amount outputs: " + std::string(mdb_strerror(dbr)));
    total = ((const uint64_t*)v.mv_data)[0];
    spent = ((const uint64_t*)v.mv_data)[1];
  }
  mdb_cursor_close(cur);
}

static void inc_per_amount_outputs(MDB_txn *txn, uint64_t amount, uint64_t total, uint64_t spent)
{
  MDB_cursor *cur;
  int dbr = mdb_cursor_open(txn, dbi_per_amount, &cur);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open cursor for per amount outputs: " + std::string(mdb_strerror(dbr)));
  MDB_val k, v;
  mdb_size_t count = 0;
  k.mv_size = sizeof(uint64_t);
  k.mv_data = (void*)&amount;
  dbr = mdb_cursor_get(cur, &k, &v, MDB_SET);
  if (dbr == 0)
  {
    total += ((const uint64_t*)v.mv_data)[0];
    spent += ((const uint64_t*)v.mv_data)[1];
  }
  else
  {
    CHECK_AND_ASSERT_THROW_MES(dbr == MDB_NOTFOUND, "Failed to get per amount outputs: " + std::string(mdb_strerror(dbr)));
  }
  uint64_t data[2] = {total, spent};
  v.mv_size = 2 * sizeof(uint64_t);
  v.mv_data = (void*)data;
  dbr = mdb_cursor_put(cur, &k, &v, 0);
  mdb_cursor_close(cur);
}

static uint64_t get_processed_txidx(const std::string &name)
{
  MDB_txn *txn;
  bool tx_active = false;

  int dbr = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
  epee::misc_utils::auto_scope_leave_caller txn_dtor = epee::misc_utils::create_scope_leave_handler([&](){if (tx_active) mdb_txn_abort(txn);});
  tx_active = true;

  uint64_t height = 0;
  MDB_val k, v;
  k.mv_data = (void*)name.c_str();
  k.mv_size = name.size();
  dbr = mdb_get(txn, dbi_processed_txidx, &k, &v);
  if (dbr != MDB_NOTFOUND)
  {
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get processed height: " + std::string(mdb_strerror(dbr)));
    height = *(const uint64_t*)v.mv_data;
  }

  dbr = mdb_txn_commit(txn);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn: " + std::string(mdb_strerror(dbr)));
  tx_active = false;

  return height;
}

static void set_processed_txidx(MDB_txn *txn, const std::string &name, uint64_t height)
{
  MDB_val k, v;
  k.mv_data = (void*)name.c_str();
  k.mv_size = name.size();
  v.mv_data = (void*)&height;
  v.mv_size = sizeof(height);
  int dbr = mdb_put(txn, dbi_processed_txidx, &k, &v, 0);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to set processed height: " + std::string(mdb_strerror(dbr)));
}

static bool get_relative_ring(MDB_txn *txn, const crypto::key_image &ki, std::vector<uint64_t> &ring)
{
  MDB_val k, v;
  k.mv_data = (void*)&ki;
  k.mv_size = sizeof(ki);
  int dbr = mdb_get(txn, dbi_relative_rings, &k, &v);
  if (dbr == MDB_NOTFOUND)
    return false;
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get relative ring: " + std::string(mdb_strerror(dbr)));
  ring = decompress_ring(std::string((const char*)v.mv_data, v.mv_size));
  return true;
}

static void set_relative_ring(MDB_txn *txn, const crypto::key_image &ki, const std::vector<uint64_t> &ring)
{
  const std::string sring = compress_ring(ring);
  MDB_val k, v;
  k.mv_data = (void*)&ki;
  k.mv_size = sizeof(ki);
  v.mv_data = (void*)sring.c_str();
  v.mv_size = sring.size();
  int dbr = mdb_put(txn, dbi_relative_rings, &k, &v, 0);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to set relative ring: " + std::string(mdb_strerror(dbr)));
}

static std::string keep_under_511(const std::string &s)
{
  if (s.size() <= 511)
    return s;
  crypto::hash hash;
  crypto::cn_fast_hash(s.data(), s.size(), hash);
  return std::string((const char*)&hash, 32);
}

static uint64_t get_ring_instances(MDB_txn *txn, uint64_t amount, const std::vector<uint64_t> &ring)
{
  const std::string sring = keep_under_511(compress_ring(amount, ring));
  MDB_val k, v;
  k.mv_data = (void*)sring.data();
  k.mv_size = sring.size();
  int dbr = mdb_get(txn, dbi_ring_instances, &k, &v);
  if (dbr == MDB_NOTFOUND)
    return 0;
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get ring instances: " + std::string(mdb_strerror(dbr)));
  return *(const uint64_t*)v.mv_data;
}

static uint64_t get_ring_subset_instances(MDB_txn *txn, uint64_t amount, const std::vector<uint64_t> &ring)
{
  uint64_t instances = get_ring_instances(txn, amount, ring);
  if (ring.size() > 11)
    return instances;

  uint64_t extra = 0;
  std::vector<uint64_t> subset;
  subset.reserve(ring.size());
  for (uint64_t mask = 1; mask < (((uint64_t)1) << ring.size()) - 1; ++mask)
  {
    subset.resize(0);
    for (size_t i = 0; i < ring.size(); ++i)
      if ((mask >> i) & 1)
        subset.push_back(ring[i]);
    extra += get_ring_instances(txn, amount, subset);
  }
  return instances + extra;
}

static uint64_t inc_ring_instances(MDB_txn *txn, uint64_t amount, const std::vector<uint64_t> &ring)
{
  const std::string sring = keep_under_511(compress_ring(amount, ring));
  MDB_val k, v;
  k.mv_data = (void*)sring.data();
  k.mv_size = sring.size();

  int dbr = mdb_get(txn, dbi_ring_instances, &k, &v);
  CHECK_AND_ASSERT_THROW_MES(!dbr || dbr == MDB_NOTFOUND, "Failed to get ring instances: " + std::string(mdb_strerror(dbr)));

  uint64_t count;
  if (dbr == MDB_NOTFOUND)
    count = 1;
  else
    count = 1 + *(const uint64_t*)v.mv_data;

  v.mv_data = &count;
  v.mv_size = sizeof(count);
  dbr = mdb_put(txn, dbi_ring_instances, &k, &v, 0);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to set ring instances: " + std::string(mdb_strerror(dbr)));

  return count;
}

static std::vector<crypto::key_image> get_key_images(MDB_txn *txn, const output_data &od)
{
  MDB_val k, v;
  k.mv_data = (void*)&od;
  k.mv_size = sizeof(od);
  int dbr = mdb_get(txn, dbi_outputs, &k, &v);
  CHECK_AND_ASSERT_THROW_MES(!dbr || dbr == MDB_NOTFOUND, "Failed to get output: " + std::string(mdb_strerror(dbr)));
  if (dbr == MDB_NOTFOUND)
    return {};
  CHECK_AND_ASSERT_THROW_MES(v.mv_size % 32 == 0, "Unexpected record size");
  std::vector<crypto::key_image> key_images;
  key_images.reserve(v.mv_size / 32);
  const crypto::key_image *ki = (const crypto::key_image*)v.mv_data;
  for (size_t n = 0; n < v.mv_size / 32; ++n)
    key_images.push_back(*ki++);
  return key_images;
}

static void add_key_image(MDB_txn *txn, const output_data &od, const crypto::key_image &ki)
{
  MDB_val k, v;
  k.mv_data = (void*)&od;
  k.mv_size = sizeof(od);
  int dbr = mdb_get(txn, dbi_outputs, &k, &v);
  CHECK_AND_ASSERT_THROW_MES(!dbr || dbr == MDB_NOTFOUND, "Failed to get output");
  std::string data;
  if (!dbr)
  {
    CHECK_AND_ASSERT_THROW_MES(v.mv_size % 32 == 0, "Unexpected record size");
    data = std::string((const char*)v.mv_data, v.mv_size);
  }
  data += std::string((const char*)&ki, sizeof(ki));

  v.mv_data = (void*)data.data();
  v.mv_size = data.size();
  dbr = mdb_put(txn, dbi_outputs, &k, &v, 0);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to set outputs: " + std::string(mdb_strerror(dbr)));
}

static bool get_stat(MDB_txn *txn, const char *key, uint64_t &data)
{
  MDB_val k, v;
  k.mv_data = (void*)key;
  k.mv_size = strlen(key);
  int dbr = mdb_get(txn, dbi_stats, &k, &v);
  if (dbr == MDB_NOTFOUND)
    return false;
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get stat record");
  CHECK_AND_ASSERT_THROW_MES(v.mv_size == sizeof(uint64_t), "Unexpected record size");
  data = *(const uint64_t*)v.mv_data;
  return true;
}

static void set_stat(MDB_txn *txn, const char *key, uint64_t data)
{
  MDB_val k, v;
  k.mv_data = (void*)key;
  k.mv_size = strlen(key);
  v.mv_data = (void*)&data;
  v.mv_size = sizeof(uint64_t);
  int dbr = mdb_put(txn, dbi_stats, &k, &v, 0);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to set stat record");
}

static void inc_stat(MDB_txn *txn, const char *key)
{
  uint64_t data;
  if (!get_stat(txn, key, data))
    data = 0;
  ++data;
  set_stat(txn, key, data);
}

static void open_db(const std::string &filename, MDB_env **env, MDB_txn **txn, MDB_cursor **cur, MDB_dbi *dbi)
{
  tools::create_directories_if_necessary(filename);

  int flags = MDB_RDONLY;
  if (db_flags & DBF_FAST)
    flags |= MDB_NOSYNC;
  if (db_flags & DBF_FASTEST)
    flags |= MDB_NOSYNC | MDB_WRITEMAP | MDB_MAPASYNC;

  int dbr = mdb_env_create(env);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LDMB environment: " + std::string(mdb_strerror(dbr)));
  dbr = mdb_env_set_maxdbs(*env, 1);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to set max env dbs: " + std::string(mdb_strerror(dbr)));
  const std::string actual_filename = filename;
  MINFO("Opening monero blockchain at " << actual_filename);
  dbr = mdb_env_open(*env, actual_filename.c_str(), flags, 0664);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open rings database file '"
      + actual_filename + "': " + std::string(mdb_strerror(dbr)));

  dbr = mdb_txn_begin(*env, NULL, MDB_RDONLY, txn);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));

  dbr = mdb_dbi_open(*txn, "output_amounts", MDB_CREATE | MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED, dbi);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
  mdb_set_dupsort(*txn, *dbi, compare_uint64);

  dbr = mdb_cursor_open(*txn, *dbi, cur);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));
}

static void close_db(MDB_env *env, MDB_txn *txn, MDB_cursor *cur, MDB_dbi dbi)
{
  mdb_txn_abort(txn);
  mdb_cursor_close(cur);
  mdb_dbi_close(env, dbi);
  mdb_env_close(env);
}

static void get_num_outputs(MDB_txn *txn, MDB_cursor *cur, MDB_dbi dbi, uint64_t &pre_rct, uint64_t &rct)
{
  uint64_t amount = 0;
  MDB_val k = { sizeof(amount), (void*)&amount }, v;
  int dbr = mdb_cursor_get(cur, &k, &v, MDB_SET);
  if (dbr == MDB_NOTFOUND)
  {
    rct = 0;
  }
  else
  {
    if (dbr) throw std::runtime_error("Record 0 not found: " + std::string(mdb_strerror(dbr)));
    mdb_size_t count = 0;
    dbr = mdb_cursor_count(cur, &count);
    if (dbr) throw std::runtime_error("Failed to count records: " + std::string(mdb_strerror(dbr)));
    rct = count;
  }
  MDB_stat s;
  dbr = mdb_stat(txn, dbi, &s);
  if (dbr) throw std::runtime_error("Failed to count records: " + std::string(mdb_strerror(dbr)));
  if (s.ms_entries < rct) throw std::runtime_error("Inconsistent records: " + std::string(mdb_strerror(dbr)));
  pre_rct = s.ms_entries - rct;
}

static crypto::hash get_genesis_block_hash(const std::string &filename)
{
  MDB_env *env;
  MDB_dbi dbi;
  MDB_txn *txn;
  int dbr;
  bool tx_active = false;

  dbr = mdb_env_create(&env);
  if (dbr) throw std::runtime_error("Failed to create LDMB environment: " + std::string(mdb_strerror(dbr)));
  dbr = mdb_env_set_maxdbs(env, 1);
  if (dbr) throw std::runtime_error("Failed to set max env dbs: " + std::string(mdb_strerror(dbr)));
  const std::string actual_filename = filename;
  dbr = mdb_env_open(env, actual_filename.c_str(), 0, 0664);
  if (dbr) throw std::runtime_error("Failed to open rings database file '"
      + actual_filename + "': " + std::string(mdb_strerror(dbr)));

  dbr = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
  if (dbr) throw std::runtime_error("Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
  epee::misc_utils::auto_scope_leave_caller txn_dtor = epee::misc_utils::create_scope_leave_handler([&](){if (tx_active) mdb_txn_abort(txn);});
  tx_active = true;

  dbr = mdb_dbi_open(txn, "block_info", MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED, &dbi);
  mdb_set_dupsort(txn, dbi, compare_uint64);
  if (dbr) throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
  uint64_t zero = 0;
  MDB_val k = { sizeof(uint64_t), (void*)&zero}, v;
  dbr = mdb_get(txn, dbi, &k, &v);
  if (dbr) throw std::runtime_error("Failed to retrieve genesis block: " + std::string(mdb_strerror(dbr)));
  crypto::hash genesis_block_hash = *(const crypto::hash*)(((const uint64_t*)v.mv_data) + 5);
  mdb_dbi_close(env, dbi);
  mdb_txn_abort(txn);
  mdb_env_close(env);
  tx_active = false;
  return genesis_block_hash;
}

static std::vector<std::pair<uint64_t, uint64_t>> load_outputs(const std::string &filename)
{
  std::vector<std::pair<uint64_t, uint64_t>> outputs;
  uint64_t amount = std::numeric_limits<uint64_t>::max();
  FILE *f;

  f = fopen(filename.c_str(), "r");
  if (!f)
  {
    MERROR("Failed to load outputs from " << filename << ": " << strerror(errno));
    return {};
  }
  while (1)
  {
    char s[256];
    if (!fgets(s, sizeof(s), f))
    {
      MERROR("Error reading from " << filename << ": " << strerror(errno));
      break;
    }
    if (feof(f))
      break;
    const size_t len = strlen(s);
    if (len > 0 && s[len - 1] == '\n')
      s[len - 1] = 0;
    if (!s[0])
      continue;
    std::pair<uint64_t, uint64_t> output;
    uint64_t offset, num_offsets;
    if (sscanf(s, "@%" PRIu64, &amount) == 1)
    {
      continue;
    }
    if (amount == std::numeric_limits<uint64_t>::max())
    {
      MERROR("Bad format in " << filename);
      continue;
    }
    if (sscanf(s, "%" PRIu64 "*%" PRIu64, &offset, &num_offsets) == 2 && num_offsets < std::numeric_limits<uint64_t>::max() - offset)
    {
      while (num_offsets-- > 0)
        outputs.push_back(std::make_pair(amount, offset++));
    }
    else if (sscanf(s, "%" PRIu64, &offset) == 1)
    {
      outputs.push_back(std::make_pair(amount, offset));
    }
    else
    {
      MERROR("Bad format in " << filename);
      continue;
    }
  }
  fclose(f);
  return outputs;
}

static bool export_spent_outputs(MDB_cursor *cur, const std::string &filename)
{
  FILE *f = fopen(filename.c_str(), "w");
  if (!f)
  {
    MERROR("Failed to open " << filename << ": " << strerror(errno));
    return false;
  }

  uint64_t pending_amount = std::numeric_limits<uint64_t>::max();
  std::vector<uint64_t> pending_offsets;
  MDB_val k, v;
  MDB_cursor_op op = MDB_FIRST;
  while (1)
  {
    int dbr = mdb_cursor_get(cur, &k, &v, op);
    if (dbr == MDB_NOTFOUND)
      break;
    op = MDB_NEXT;
    if (dbr)
    {
      fclose(f);
      MERROR("Failed to enumerate spent outputs: " << mdb_strerror(dbr));
      return false;
    }
    const uint64_t amount = *(const uint64_t*)k.mv_data;
    const uint64_t offset = *(const uint64_t*)v.mv_data;
    if (!pending_offsets.empty() && (amount != pending_amount || pending_offsets.back()+1 != offset))
    {
      if (pending_offsets.size() == 1)
        fprintf(f, "%" PRIu64 "\n", pending_offsets.front());
      else
        fprintf(f, "%" PRIu64 "*%zu\n", pending_offsets.front(), pending_offsets.size());
      pending_offsets.clear();
    }
    if (pending_amount != amount)
    {
      fprintf(f, "@%" PRIu64 "\n", amount);
      pending_amount = amount;
    }
    pending_offsets.push_back(offset);
  }
  if (!pending_offsets.empty())
  {
    if (pending_offsets.size() == 1)
      fprintf(f, "%" PRIu64 "\n", pending_offsets.front());
    else
      fprintf(f, "%" PRIu64 "*%zu\n", pending_offsets.front(), pending_offsets.size());
    pending_offsets.clear();
  }
  fclose(f);
  return true;
}

int main(int argc, char* argv[])
{
  TRY_ENTRY();

  epee::string_tools::set_module_name_and_folder(argv[0]);

  std::string default_db_type = "lmdb";

  std::string available_dbs = cryptonote::blockchain_db_types(", ");
  available_dbs = "available: " + available_dbs;

  uint32_t log_level = 0;

  tools::on_startup();

  boost::filesystem::path output_file_path;

  po::options_description desc_cmd_only("Command line options");
  po::options_description desc_cmd_sett("Command line options and settings options");
  const command_line::arg_descriptor<std::string> arg_blackball_db_dir = {
      "spent-output-db-dir", "Specify spent output database directory",
      get_default_db_path(),
  };
  const command_line::arg_descriptor<std::string> arg_log_level  = {"log-level",  "0-4 or categories", ""};
  const command_line::arg_descriptor<std::string> arg_database = {
    "database", available_dbs.c_str(), default_db_type
  };
  const command_line::arg_descriptor<bool> arg_rct_only  = {"rct-only", "Only work on ringCT outputs", false};
  const command_line::arg_descriptor<bool> arg_check_subsets  = {"check-subsets", "Check ring subsets (very expensive)", false};
  const command_line::arg_descriptor<bool> arg_verbose  = {"verbose", "Verbose output)", false};
  const command_line::arg_descriptor<std::vector<std::string> > arg_inputs = {"inputs", "Path to Monero DB, and path to any fork DBs"};
  const command_line::arg_descriptor<std::string> arg_db_sync_mode = {
    "db-sync-mode"
  , "Specify sync option, using format [safe|fast|fastest]:[nrecords_per_sync]." 
  , "fast:1000"
  };
  const command_line::arg_descriptor<std::string> arg_extra_spent_list = {"extra-spent-list", "Optional list of known spent outputs",""};
  const command_line::arg_descriptor<std::string> arg_export = {"export", "Filename to export the backball list to"};
  const command_line::arg_descriptor<bool> arg_force_chain_reaction_pass = {"force-chain-reaction-pass", "Run the chain reaction pass even if no new blockchain data was processed"};

  command_line::add_arg(desc_cmd_sett, arg_blackball_db_dir);
  command_line::add_arg(desc_cmd_sett, arg_log_level);
  command_line::add_arg(desc_cmd_sett, arg_database);
  command_line::add_arg(desc_cmd_sett, arg_rct_only);
  command_line::add_arg(desc_cmd_sett, arg_check_subsets);
  command_line::add_arg(desc_cmd_sett, arg_verbose);
  command_line::add_arg(desc_cmd_sett, arg_db_sync_mode);
  command_line::add_arg(desc_cmd_sett, arg_extra_spent_list);
  command_line::add_arg(desc_cmd_sett, arg_export);
  command_line::add_arg(desc_cmd_sett, arg_force_chain_reaction_pass);
  command_line::add_arg(desc_cmd_sett, arg_inputs);
  command_line::add_arg(desc_cmd_only, command_line::arg_help);

  po::options_description desc_options("Allowed options");
  desc_options.add(desc_cmd_only).add(desc_cmd_sett);

  po::positional_options_description positional_options;
  positional_options.add(arg_inputs.name, -1);

  po::variables_map vm;
  bool r = command_line::handle_error_helper(desc_options, [&]()
  {
    auto parser = po::command_line_parser(argc, argv).options(desc_options).positional(positional_options);
    po::store(parser.run(), vm);
    po::notify(vm);
    return true;
  });
  if (! r)
    return 1;

  if (command_line::get_arg(vm, command_line::arg_help))
  {
    std::cout << "Monero '" << MONERO_RELEASE_NAME << "' (v" << MONERO_VERSION_FULL << ")" << ENDL << ENDL;
    std::cout << desc_options << std::endl;
    return 1;
  }

  mlog_configure(mlog_get_default_log_path("monero-blockchain-mark-spent-outputs.log"), true);
  if (!command_line::is_arg_defaulted(vm, arg_log_level))
    mlog_set_log(command_line::get_arg(vm, arg_log_level).c_str());
  else
    mlog_set_log(std::string(std::to_string(log_level) + ",bcutil:INFO").c_str());

  LOG_PRINT_L0("Starting...");

  output_file_path = command_line::get_arg(vm, arg_blackball_db_dir);
  bool opt_rct_only = command_line::get_arg(vm, arg_rct_only);
  bool opt_check_subsets = command_line::get_arg(vm, arg_check_subsets);
  bool opt_verbose = command_line::get_arg(vm, arg_verbose);
  bool opt_force_chain_reaction_pass = command_line::get_arg(vm, arg_force_chain_reaction_pass);
  std::string opt_export = command_line::get_arg(vm, arg_export);
  std::string extra_spent_list = command_line::get_arg(vm, arg_extra_spent_list);
  std::vector<std::pair<uint64_t, uint64_t>> extra_spent_outputs = extra_spent_list.empty() ? std::vector<std::pair<uint64_t, uint64_t>>() : load_outputs(extra_spent_list);

  std::string db_type = command_line::get_arg(vm, arg_database);
  if (!cryptonote::blockchain_valid_db_type(db_type))
  {
    std::cerr << "Invalid database type: " << db_type << std::endl;
    return 1;
  }

  std::string db_sync_mode = command_line::get_arg(vm, arg_db_sync_mode);
  if (!parse_db_sync_mode(db_sync_mode))
  {
    MERROR("Invalid db sync mode: " << db_sync_mode);
    return 1;
  }

  const std::vector<std::string> inputs = command_line::get_arg(vm, arg_inputs);
  if (inputs.empty())
  {
    LOG_PRINT_L0("No inputs given");
    return 1;
  }

  const std::string cache_dir = (output_file_path / "spent-outputs-cache").string();
  init(cache_dir);

  LOG_PRINT_L0("Scanning for spent outputs...");

  size_t done = 0;

  const uint64_t start_blackballed_outputs = get_num_spent_outputs();

  tools::ringdb ringdb(output_file_path.string(), epee::string_tools::pod_to_hex(get_genesis_block_hash(inputs[0])));

  bool stop_requested = false;
  tools::signal_handler::install([&stop_requested](int type) {
    stop_requested = true;
  });

  int dbr = resize_env(cache_dir.c_str());
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to resize LMDB database: " + std::string(mdb_strerror(dbr)));

  // open first db
  MDB_env *env0;
  MDB_txn *txn0;
  MDB_dbi dbi0;
  MDB_cursor *cur0;
  open_db(inputs[0], &env0, &txn0, &cur0, &dbi0);

  if (!extra_spent_outputs.empty())
  {
    MINFO("Adding " << extra_spent_outputs.size() << " extra spent outputs");
    MDB_txn *txn;
    int dbr = mdb_txn_begin(env, NULL, 0, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    MDB_cursor *cur;
    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));

    std::vector<std::pair<uint64_t, uint64_t>> blackballs;
    for (const std::pair<uint64_t, uint64_t> &output: extra_spent_outputs)
    {
      if (!is_output_spent(cur, output_data(output.first, output.second)))
      {
        blackballs.push_back(output);
        if (add_spent_output(cur, output_data(output.first, output.second)))
          inc_stat(txn, output.first ? "pre-rct-extra" : "rct-ring-extra");
      }
    }
    if (!blackballs.empty())
    {
      ringdb.blackball(blackballs);
      blackballs.clear();
    }
    mdb_cursor_close(cur);
    dbr = mdb_txn_commit(txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
  }

  for (size_t n = 0; n < inputs.size(); ++n)
  {
    const std::string canonical = boost::filesystem::canonical(inputs[n]).string();
    uint64_t start_idx = get_processed_txidx(canonical);
    if (n > 0 && start_idx == 0)
    {
      start_idx = find_first_diverging_transaction(inputs[0], inputs[n]);
      LOG_PRINT_L0("First diverging transaction at " << start_idx);
    }
    LOG_PRINT_L0("Reading blockchain from " << inputs[n] << " from " << start_idx);
    MDB_txn *txn;
    int dbr = mdb_txn_begin(env, NULL, 0, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    MDB_cursor *cur;
    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
    size_t records = 0;
    const std::string filename = inputs[n];
    std::vector<std::pair<uint64_t, uint64_t>> blackballs;
    uint64_t n_txes;
    for_all_transactions(filename, start_idx, n_txes, [&](const cryptonote::transaction_prefix &tx)->bool
    {
      std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
      const bool miner_tx = tx.vin.size() == 1 && tx.vin[0].type() == typeid(txin_gen);
      for (const auto &in: tx.vin)
      {
        if (in.type() != typeid(txin_to_key))
          continue;
        const auto &txin = boost::get<txin_to_key>(in);
        if (opt_rct_only && txin.amount != 0)
          continue;

        const std::vector<uint64_t> absolute = cryptonote::relative_output_offsets_to_absolute(txin.key_offsets);
        if (n == 0)
          for (uint64_t out: absolute)
            add_key_image(txn, output_data(txin.amount, out), txin.k_image);

        std::vector<uint64_t> relative_ring;
        std::vector<uint64_t> new_ring = canonicalize(txin.key_offsets);
        const uint32_t ring_size = txin.key_offsets.size();
        const uint64_t instances = inc_ring_instances(txn, txin.amount, new_ring);
        uint64_t pa_total = 0, pa_spent = 0;
        if (!opt_rct_only)
          get_per_amount_outputs(txn, txin.amount, pa_total, pa_spent);
        if (n == 0 && ring_size == 1)
        {
          const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, absolute[0]);
          if (opt_verbose)
          {
            MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in a 1-ring");
            std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
          }
          blackballs.push_back(output);
          if (add_spent_output(cur, output_data(txin.amount, absolute[0])))
            inc_stat(txn, txin.amount ? "pre-rct-ring-size-1" : "rct-ring-size-1");
        }
        else if (n == 0 && instances == new_ring.size())
        {
          for (size_t o = 0; o < new_ring.size(); ++o)
          {
            const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, absolute[o]);
            if (opt_verbose)
            {
              MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in " << new_ring.size() << " identical " << new_ring.size() << "-rings");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            }
            blackballs.push_back(output);
            if (add_spent_output(cur, output_data(txin.amount, absolute[o])))
              inc_stat(txn, txin.amount ? "pre-rct-duplicate-rings" : "rct-duplicate-rings");
          }
        }
        else if (n == 0 && !opt_rct_only && pa_spent + 1 == pa_total)
        {
          for (size_t o = 0; o < pa_total; ++o)
          {
            const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, o);
            if (opt_verbose)
            {
              MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to as many outputs of that amount being spent as exist so far");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            }
            blackballs.push_back(output);
            if (add_spent_output(cur, output_data(txin.amount, o)))
              inc_stat(txn, txin.amount ? "pre-rct-full-count" : "rct-full-count");
          }
        }
        else if (n == 0 && opt_check_subsets && get_ring_subset_instances(txn, txin.amount, new_ring) >= new_ring.size())
        {
          for (size_t o = 0; o < new_ring.size(); ++o)
          {
            const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, absolute[o]);
            if (opt_verbose)
            {
              MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in " << new_ring.size() << " subsets of " << new_ring.size() << "-rings");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            }
            blackballs.push_back(output);
            if (add_spent_output(cur, output_data(txin.amount, absolute[o])))
              inc_stat(txn, txin.amount ? "pre-rct-subset-rings" : "rct-subset-rings");
          }
        }
        else if (n > 0 && get_relative_ring(txn, txin.k_image, relative_ring))
        {
          MDEBUG("Key image " << txin.k_image << " already seen: rings " <<
              boost::join(relative_ring | boost::adaptors::transformed([](uint64_t out){return std::to_string(out);}), " ") <<
              ", " << boost::join(txin.key_offsets | boost::adaptors::transformed([](uint64_t out){return std::to_string(out);}), " "));
          std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
          if (relative_ring != txin.key_offsets)
          {
            MDEBUG("Rings are different");
            std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            const std::vector<uint64_t> r0 = cryptonote::relative_output_offsets_to_absolute(relative_ring);
            const std::vector<uint64_t> r1 = cryptonote::relative_output_offsets_to_absolute(txin.key_offsets);
            std::vector<uint64_t> common;
            for (uint64_t out: r0)
            {
              if (std::find(r1.begin(), r1.end(), out) != r1.end())
                common.push_back(out);
            }
            if (common.empty())
            {
              MERROR("Rings for the same key image are disjoint");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            }
            else if (common.size() == 1)
            {
              const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, common[0]);
              if (opt_verbose)
              {
                MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in rings with a single common element");
                std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
              }
              blackballs.push_back(output);
              if (add_spent_output(cur, output_data(txin.amount, common[0])))
                inc_stat(txn, txin.amount ? "pre-rct-key-image-attack" : "rct-key-image-attack");
            }
            else
            {
              MDEBUG("The intersection has more than one element, it's still ok");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
              for (const auto &out: r0)
                if (std::find(common.begin(), common.end(), out) != common.end())
                  new_ring.push_back(out);
              new_ring = cryptonote::absolute_output_offsets_to_relative(new_ring);
            }
          }
        }
        if (n == 0)
        {
          set_relative_ring(txn, txin.k_image, new_ring);
          if (!opt_rct_only)
            inc_per_amount_outputs(txn, txin.amount, 0, 1);
        }
      }
      set_processed_txidx(txn, canonical, start_idx+1);
      if (!opt_rct_only)
      {
        for (const auto &out: tx.vout)
        {
          uint64_t amount = out.amount;
          if (miner_tx && tx.version >= 2)
            amount = 0;

          if (opt_rct_only && amount != 0)
            continue;
          if (out.target.type() != typeid(txout_to_key))
            continue;
          inc_per_amount_outputs(txn, amount, 1, 0);
        }
      }

      ++records;
      if (records >= records_per_sync)
      {
        if (!blackballs.empty())
        {
          ringdb.blackball(blackballs);
          blackballs.clear();
        }
        mdb_cursor_close(cur);
        dbr = mdb_txn_commit(txn);
        CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
        int dbr = resize_env(cache_dir.c_str());
        CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to resize LMDB database: " + std::string(mdb_strerror(dbr)));
        dbr = mdb_txn_begin(env, NULL, 0, &txn);
        CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
        dbr = mdb_cursor_open(txn, dbi_spent, &cur);
        CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
        records = 0;
      }

      if (stop_requested)
      {
        MINFO("Stopping scan...");
        return false;
      }
      return true;
    });
    mdb_cursor_close(cur);
    dbr = mdb_txn_commit(txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
    LOG_PRINT_L0("blockchain from " << inputs[n] << " processed till tx idx " << start_idx);
    if (stop_requested)
      break;
  }

  std::vector<output_data> work_spent;

  if (stop_requested)
    goto skip_secondary_passes;

  if (opt_force_chain_reaction_pass || get_num_spent_outputs() > start_blackballed_outputs)
  {
    MDB_txn *txn;
    dbr = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    work_spent = get_spent_outputs(txn);
    mdb_txn_abort(txn);
  }

  while (!work_spent.empty())
  {
    LOG_PRINT_L0("Secondary pass on " << work_spent.size() << " spent outputs");

    int dbr = resize_env(cache_dir.c_str());
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to resize LMDB database: " + std::string(mdb_strerror(dbr)));

    MDB_txn *txn;
    dbr = mdb_txn_begin(env, NULL, 0, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    MDB_cursor *cur;
    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));

    std::vector<std::pair<uint64_t, uint64_t>> blackballs;
    std::vector<output_data> scan_spent = std::move(work_spent);
    work_spent.clear();
    for (const output_data &od: scan_spent)
    {
      std::vector<crypto::key_image> key_images = get_key_images(txn, od);
      for (const crypto::key_image &ki: key_images)
      {
        std::vector<uint64_t> relative_ring;
        CHECK_AND_ASSERT_THROW_MES(get_relative_ring(txn, ki, relative_ring), "Relative ring not found");
        std::vector<uint64_t> absolute = cryptonote::relative_output_offsets_to_absolute(relative_ring);
        size_t known = 0;
        uint64_t last_unknown = 0;
        for (uint64_t out: absolute)
        {
          output_data new_od(od.amount, out);
          if (is_output_spent(cur, new_od))
            ++known;
          else
            last_unknown = out;
        }
        if (known == absolute.size() - 1)
        {
          const std::pair<uint64_t, uint64_t> output = std::make_pair(od.amount, last_unknown);
          if (opt_verbose)
          {
            MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in a " <<
                absolute.size() << "-ring where all other outputs are known to be spent");
          }
          blackballs.push_back(output);
          if (add_spent_output(cur, output_data(od.amount, last_unknown)))
            inc_stat(txn, od.amount ? "pre-rct-chain-reaction" : "rct-chain-reaction");
          work_spent.push_back(output_data(od.amount, last_unknown));
        }
      }

      if (stop_requested)
      {
        MINFO("Stopping secondary passes. Secondary passes are not incremental, they will re-run fully.");
        return 0;
      }
    }
    if (!blackballs.empty())
    {
      ringdb.blackball(blackballs);
      blackballs.clear();
    }
    mdb_cursor_close(cur);
    dbr = mdb_txn_commit(txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
  }

skip_secondary_passes:
  uint64_t diff = get_num_spent_outputs() - start_blackballed_outputs;
  LOG_PRINT_L0(std::to_string(diff) << " new outputs marked as spent, " << get_num_spent_outputs() << " total outputs marked as spent");

  MDB_txn *txn;
  dbr = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
  uint64_t pre_rct = 0, rct = 0;
  get_num_outputs(txn0, cur0, dbi0, pre_rct, rct);
  MINFO("Total pre-rct outputs: " << pre_rct);
  MINFO("Total rct outputs: " << rct);
  static const struct { const char *key; uint64_t base; } stat_keys[] = {
    { "pre-rct-ring-size-1", pre_rct }, { "rct-ring-size-1", rct },
    { "pre-rct-duplicate-rings", pre_rct }, { "rct-duplicate-rings", rct },
    { "pre-rct-subset-rings", pre_rct }, { "rct-subset-rings", rct },
    { "pre-rct-full-count", pre_rct }, { "rct-full-count", rct },
    { "pre-rct-key-image-attack", pre_rct }, { "rct-key-image-attack", rct },
    { "pre-rct-extra", pre_rct }, { "rct-ring-extra", rct },
    { "pre-rct-chain-reaction", pre_rct }, { "rct-chain-reaction", rct },
  };
  for (const auto &key: stat_keys)
  {
    uint64_t data;
    if (!get_stat(txn, key.key, data))
      data = 0;
    float percent = key.base ? 100.0f * data / key.base : 0.0f;
    MINFO(key.key << ": " << data << " (" << percent << "%)");
  }
  mdb_txn_abort(txn);

  if (!opt_export.empty())
  {
    MDB_txn *txn;
    int dbr = mdb_txn_begin(env, NULL, 0, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    MDB_cursor *cur;
    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
    export_spent_outputs(cur, opt_export);
    mdb_cursor_close(cur);
    mdb_txn_abort(txn);
  }

  LOG_PRINT_L0("Blockchain spent output data exported OK");
  close_db(env0, txn0, cur0, dbi0);
  close();
  return 0;

  CATCH_ENTRY("Error", 1);
}