summaryrefslogtreecommitdiffstats
path: root/storage/rocksdb/rdb_converter.cc
blob: 65f0b81cc7fdb54f9d4a949d5f67da09281575c5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
/*
   Copyright (c) 2015, Facebook, Inc.

   This program is f
   i the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include <my_global.h>

/* This C++ file's header file */
#include "./rdb_converter.h"

/* Standard C++ header files */
#include <algorithm>
#include <map>
#include <string>
#include <vector>

/* MySQL header files */
#include "./field.h"
#include "./key.h"
#include "./m_ctype.h"
#include "./my_bit.h"
#include "./my_bitmap.h"
#include "./sql_table.h"


/* MyRocks header files */
#include "./ha_rocksdb.h"
#include "./ha_rocksdb_proto.h"
#include "./my_stacktrace.h"
#include "./rdb_cf_manager.h"
#include "./rdb_psi.h"
#include "./rdb_utils.h"


namespace myrocks {

void dbug_modify_key_varchar8(String *on_disk_rec) {
  std::string res;
  // The key starts with index number
  res.append(on_disk_rec->ptr(), Rdb_key_def::INDEX_NUMBER_SIZE);

  // Then, a mem-comparable form of a varchar(8) value.
  res.append("ABCDE\0\0\0\xFC", 9);
  on_disk_rec->length(0);
  on_disk_rec->append(res.data(), res.size());
}

/*
  Convert field from rocksdb storage format into Mysql Record format
  @param    buf         OUT          start memory to fill converted data
  @param    offset      IN/OUT       decoded data is stored in buf + offset
  @param    table       IN           current table
  @param    field       IN           current field
  @param    reader      IN           rocksdb value slice reader
  @param    decode      IN           whether to decode current field
  @return
    0      OK
    other  HA_ERR error code (can be SE-specific)
*/
int Rdb_convert_to_record_value_decoder::decode(uchar *const buf, uint *offset,
                                                TABLE *table,
                                                my_core::Field *field,
                                                Rdb_field_encoder *field_dec,
                                                Rdb_string_reader *reader,
                                                bool decode, bool is_null) {
  int err = HA_EXIT_SUCCESS;

  uint field_offset = field->ptr - table->record[0];
  *offset = field_offset;
  uint null_offset = field->null_offset();
  bool maybe_null = field->real_maybe_null();
  field->move_field(buf + field_offset,
                    maybe_null ? buf + null_offset : nullptr, field->null_bit);

  if (is_null) {
    if (decode) {
      // This sets the NULL-bit of this record
      field->set_null();
      /*
        Besides that, set the field value to default value. CHECKSUM TABLE
        depends on this.
      */
      memcpy(field->ptr, table->s->default_values + field_offset,
             field->pack_length());
    }
  } else {
    if (decode) {
      // sets non-null bits for this record
      field->set_notnull();
    }

    if (field_dec->m_field_type == MYSQL_TYPE_BLOB) {
      err = decode_blob(table, field, reader, decode);
    } else if (field_dec->m_field_type == MYSQL_TYPE_VARCHAR) {
      err = decode_varchar(field, reader, decode);
    } else {
      err = decode_fixed_length_field(field, field_dec, reader, decode);
    }
  }

  // Restore field->ptr and field->null_ptr
  field->move_field(table->record[0] + field_offset,
                    maybe_null ? table->record[0] + null_offset : nullptr,
                    field->null_bit);

  return err;
}

/*
  Convert blob from rocksdb storage format into Mysql Record format
  @param    table       IN           current table
  @param    field       IN           current field
  @param    reader      IN           rocksdb value slice reader
  @param    decode      IN           whether to decode current field
  @return
    0      OK
    other  HA_ERR error code (can be SE-specific)
*/
int Rdb_convert_to_record_value_decoder::decode_blob(TABLE *table, Field *field,
                                                     Rdb_string_reader *reader,
                                                     bool decode) {
  my_core::Field_blob *blob = (my_core::Field_blob *)field;

  // Get the number of bytes needed to store length
  const uint length_bytes = blob->pack_length() - portable_sizeof_char_ptr;

  const char *data_len_str;
  if (!(data_len_str = reader->read(length_bytes))) {
    return HA_ERR_ROCKSDB_CORRUPT_DATA;
  }

  memcpy(blob->ptr, data_len_str, length_bytes);
  uint32 data_len =
      blob->get_length(reinterpret_cast<const uchar *>(data_len_str),
                       length_bytes);
  const char *blob_ptr;
  if (!(blob_ptr = reader->read(data_len))) {
    return HA_ERR_ROCKSDB_CORRUPT_DATA;
  }

  if (decode) {
    // set 8-byte pointer to 0, like innodb does (relevant for 32-bit
    // platforms)
    memset(blob->ptr + length_bytes, 0, 8);
    memcpy(blob->ptr + length_bytes, &blob_ptr, sizeof(uchar **));
  }

  return HA_EXIT_SUCCESS;
}

/*
  Convert fixed length field from rocksdb storage format into Mysql Record
  format
  @param    field       IN           current field
  @param    field_dec   IN           data structure conttain field encoding data
  @param    reader      IN           rocksdb value slice reader
  @param    decode      IN           whether to decode current field
  @return
    0      OK
    other  HA_ERR error code (can be SE-specific)
*/
int Rdb_convert_to_record_value_decoder::decode_fixed_length_field(
    my_core::Field *const field, Rdb_field_encoder *field_dec,
    Rdb_string_reader *const reader, bool decode) {
  uint len = field_dec->m_pack_length_in_rec;
  if (len > 0) {
    const char *data_bytes;
    if ((data_bytes = reader->read(len)) == nullptr) {
      return HA_ERR_ROCKSDB_CORRUPT_DATA;
    }

    if (decode) {
      memcpy(field->ptr, data_bytes, len);
    }
  }

  return HA_EXIT_SUCCESS;
}

/*
  Convert varchar field from rocksdb storage format into Mysql Record format
  @param    field       IN           current field
  @param    field_dec   IN           data structure conttain field encoding data
  @param    reader      IN           rocksdb value slice reader
  @param    decode      IN           whether to decode current field
  @return
    0      OK
    other  HA_ERR error code (can be SE-specific)
*/
int Rdb_convert_to_record_value_decoder::decode_varchar(
    Field *field, Rdb_string_reader *const reader, bool decode) {
  my_core::Field_varstring *const field_var = (my_core::Field_varstring *)field;

  const char *data_len_str;
  if (!(data_len_str = reader->read(field_var->length_bytes))) {
    return HA_ERR_ROCKSDB_CORRUPT_DATA;
  }

  uint data_len;
  // field_var->length_bytes is 1 or 2
  if (field_var->length_bytes == 1) {
    data_len = (uchar)data_len_str[0];
  } else {
    DBUG_ASSERT(field_var->length_bytes == 2);
    data_len = uint2korr(data_len_str);
  }

  if (data_len > field_var->field_length) {
    // The data on disk is longer than table DDL allows?
    return HA_ERR_ROCKSDB_CORRUPT_DATA;
  }

  if (!reader->read(data_len)) {
    return HA_ERR_ROCKSDB_CORRUPT_DATA;
  }

  if (decode) {
    memcpy(field_var->ptr, data_len_str, field_var->length_bytes + data_len);
  }

  return HA_EXIT_SUCCESS;
}

template <typename value_field_decoder>
Rdb_value_field_iterator<value_field_decoder>::Rdb_value_field_iterator(
    TABLE *table, Rdb_string_reader *value_slice_reader,
    const Rdb_converter *rdb_converter, uchar *const buf)
    : m_buf(buf) {
  DBUG_ASSERT(table != nullptr);
  DBUG_ASSERT(buf != nullptr);

  m_table = table;
  m_value_slice_reader = value_slice_reader;
  auto fields = rdb_converter->get_decode_fields();
  m_field_iter = fields->begin();
  m_field_end = fields->end();
  m_null_bytes = rdb_converter->get_null_bytes();
  m_offset = 0;
}

// Iterate each requested field and decode one by one
template <typename value_field_decoder>
int Rdb_value_field_iterator<value_field_decoder>::next() {
  int err = HA_EXIT_SUCCESS;
  while (m_field_iter != m_field_end) {
    m_field_dec = m_field_iter->m_field_enc;
    bool decode = m_field_iter->m_decode;
    bool maybe_null = m_field_dec->maybe_null();
    // This is_null value is bind to how stroage format store its value
    m_is_null = maybe_null && ((m_null_bytes[m_field_dec->m_null_offset] &
                                m_field_dec->m_null_mask) != 0);

    // Skip the bytes we need to skip
    int skip = m_field_iter->m_skip;
    if (skip && !m_value_slice_reader->read(skip)) {
      return HA_ERR_ROCKSDB_CORRUPT_DATA;
    }

    m_field = m_table->field[m_field_dec->m_field_index];
    // Decode each field
    err = value_field_decoder::decode(m_buf, &m_offset, m_table, m_field,
                                      m_field_dec, m_value_slice_reader, decode,
                                      m_is_null);
    if (err != HA_EXIT_SUCCESS) {
      return err;
    }
    m_field_iter++;
    // Only break for the field that are actually decoding rather than skipping
    if (decode) {
      break;
    }
  }
  return err;
}

template <typename value_field_decoder>
bool Rdb_value_field_iterator<value_field_decoder>::end_of_fields() const {
  return m_field_iter == m_field_end;
}

template <typename value_field_decoder>
Field *Rdb_value_field_iterator<value_field_decoder>::get_field() const {
  DBUG_ASSERT(m_field != nullptr);
  return m_field;
}

template <typename value_field_decoder>
void *Rdb_value_field_iterator<value_field_decoder>::get_dst() const {
  DBUG_ASSERT(m_buf != nullptr);
  return m_buf + m_offset;
}

template <typename value_field_decoder>
int Rdb_value_field_iterator<value_field_decoder>::get_field_index() const {
  DBUG_ASSERT(m_field_dec != nullptr);
  return m_field_dec->m_field_index;
}

template <typename value_field_decoder>
enum_field_types Rdb_value_field_iterator<value_field_decoder>::get_field_type()
    const {
  DBUG_ASSERT(m_field_dec != nullptr);
  return m_field_dec->m_field_type;
}

template <typename value_field_decoder>
bool Rdb_value_field_iterator<value_field_decoder>::is_null() const {
  DBUG_ASSERT(m_field != nullptr);
  return m_is_null;
}

/*
  Initialize Rdb_converter with table data
  @param    thd        IN      Thread context
  @param    tbl_def    IN      MyRocks table definition
  @param    table      IN      Current open table
*/
Rdb_converter::Rdb_converter(const THD *thd, const Rdb_tbl_def *tbl_def,
                             TABLE *table)
    : m_thd(thd), m_tbl_def(tbl_def), m_table(table) {
  DBUG_ASSERT(thd != nullptr);
  DBUG_ASSERT(tbl_def != nullptr);
  DBUG_ASSERT(table != nullptr);

  m_key_requested = false;
  m_verify_row_debug_checksums = false;
  m_maybe_unpack_info = false;
  m_row_checksums_checked = 0;
  m_null_bytes = nullptr;
  setup_field_encoders();
}

Rdb_converter::~Rdb_converter() {
  my_free(m_encoder_arr);
  m_encoder_arr = nullptr;
  // These are needed to suppress valgrind errors in rocksdb.partition
  m_storage_record.free();
}

/*
  Decide storage type for each encoder
*/
void Rdb_converter::get_storage_type(Rdb_field_encoder *const encoder,
                                     const uint kp) {
  auto pk_descr =
      m_tbl_def->m_key_descr_arr[ha_rocksdb::pk_index(m_table, m_tbl_def)];
  // STORE_SOME uses unpack_info.
  if (pk_descr->has_unpack_info(kp)) {
    DBUG_ASSERT(pk_descr->can_unpack(kp));
    encoder->m_storage_type = Rdb_field_encoder::STORE_SOME;
    m_maybe_unpack_info = true;
  } else if (pk_descr->can_unpack(kp)) {
    encoder->m_storage_type = Rdb_field_encoder::STORE_NONE;
  }
}

/*
  @brief
    Setup which fields will be unpacked when reading rows

  @detail
    Three special cases when we still unpack all fields:
    - When client requires decode_all_fields, such as this table is being
  updated (m_lock_rows==RDB_LOCK_WRITE).
    - When @@rocksdb_verify_row_debug_checksums is ON (In this mode, we need to
  read all fields to find whether there is a row checksum at the end. We could
  skip the fields instead of decoding them, but currently we do decoding.)
    - On index merge as bitmap is cleared during that operation

  @seealso
    Rdb_converter::setup_field_encoders()
    Rdb_converter::convert_record_from_storage_format()
*/
void Rdb_converter::setup_field_decoders(const MY_BITMAP *field_map,
                                         bool decode_all_fields) {
  m_key_requested = false;
  m_decoders_vect.clear();
  int last_useful = 0;
  int skip_size = 0;

  for (uint i = 0; i < m_table->s->fields; i++) {
    // bitmap is cleared on index merge, but it still needs to decode columns
    bool field_requested =
        decode_all_fields || m_verify_row_debug_checksums ||
        bitmap_is_clear_all(field_map) ||
        bitmap_is_set(field_map, m_table->field[i]->field_index);

    // We only need the decoder if the whole record is stored.
    if (m_encoder_arr[i].m_storage_type != Rdb_field_encoder::STORE_ALL) {
      // the field potentially needs unpacking
      if (field_requested) {
        // the field is in the read set
        m_key_requested = true;
      }
      continue;
    }

    if (field_requested) {
      // We will need to decode this field
      m_decoders_vect.push_back({&m_encoder_arr[i], true, skip_size});
      last_useful = m_decoders_vect.size();
      skip_size = 0;
    } else {
      if (m_encoder_arr[i].uses_variable_len_encoding() ||
          m_encoder_arr[i].maybe_null()) {
        // For variable-length field, we need to read the data and skip it
        m_decoders_vect.push_back({&m_encoder_arr[i], false, skip_size});
        skip_size = 0;
      } else {
        // Fixed-width field can be skipped without looking at it.
        // Add appropriate skip_size to the next field.
        skip_size += m_encoder_arr[i].m_pack_length_in_rec;
      }
    }
  }

  // It could be that the last few elements are varchars that just do
  // skipping. Remove them.
  m_decoders_vect.erase(m_decoders_vect.begin() + last_useful,
                        m_decoders_vect.end());
}

void Rdb_converter::setup_field_encoders() {
  uint null_bytes_length = 0;
  uchar cur_null_mask = 0x1;

  m_encoder_arr = static_cast<Rdb_field_encoder *>(
      my_malloc(PSI_INSTRUMENT_ME, m_table->s->fields * sizeof(Rdb_field_encoder), MYF(0)));
  if (m_encoder_arr == nullptr) {
    return;
  }

  for (uint i = 0; i < m_table->s->fields; i++) {
    Field *const field = m_table->field[i];
    m_encoder_arr[i].m_storage_type = Rdb_field_encoder::STORE_ALL;

    /*
      Check if this field is
      - a part of primary key, and
      - it can be decoded back from its key image.
      If both hold, we don't need to store this field in the value part of
      RocksDB's key-value pair.

      If hidden pk exists, we skip this check since the field will never be
      part of the hidden pk.
    */
    if (!Rdb_key_def::table_has_hidden_pk(m_table)) {
      KEY *const pk_info = &m_table->key_info[m_table->s->primary_key];
      for (uint kp = 0; kp < pk_info->user_defined_key_parts; kp++) {
        // key_part->fieldnr is counted from 1
        if (field->field_index + 1 == pk_info->key_part[kp].fieldnr) {
          get_storage_type(&m_encoder_arr[i], kp);
          break;
        }
      }
    }

    m_encoder_arr[i].m_field_type = field->real_type();
    m_encoder_arr[i].m_field_index = i;
    m_encoder_arr[i].m_pack_length_in_rec = field->pack_length_in_rec();

    if (field->real_maybe_null()) {
      m_encoder_arr[i].m_null_mask = cur_null_mask;
      m_encoder_arr[i].m_null_offset = null_bytes_length;
      if (cur_null_mask == 0x80) {
        cur_null_mask = 0x1;
        null_bytes_length++;
      } else {
        cur_null_mask = cur_null_mask << 1;
      }
    } else {
      m_encoder_arr[i].m_null_mask = 0;
    }
  }

  // Count the last, unfinished NULL-bits byte
  if (cur_null_mask != 0x1) {
    null_bytes_length++;
  }

  m_null_bytes_length_in_record = null_bytes_length;
}

/*
  EntryPoint for Decode:
  Decode key slice(if requested) and value slice using built-in field
  decoders
  @param     key_def        IN          key definition to decode
  @param     dst            OUT         Mysql buffer to fill decoded content
  @param     key_slice      IN          RocksDB key slice to decode
  @param     value_slice    IN          RocksDB value slice to decode
  @return
    0      OK
    other  HA_ERR error code (can be SE-specific)
*/
int Rdb_converter::decode(const std::shared_ptr<Rdb_key_def> &key_def,
                          uchar *dst,  // address to fill data
                          const rocksdb::Slice *key_slice,
                          const rocksdb::Slice *value_slice) {
  // Currently only support decode primary key, Will add decode secondary later
  DBUG_ASSERT(key_def->m_index_type == Rdb_key_def::INDEX_TYPE_PRIMARY ||
              key_def->m_index_type == Rdb_key_def::INDEX_TYPE_HIDDEN_PRIMARY);

  const rocksdb::Slice *updated_key_slice = key_slice;
#ifndef DBUG_OFF
  String last_rowkey;
  last_rowkey.copy(key_slice->data(), key_slice->size(), &my_charset_bin);
  DBUG_EXECUTE_IF("myrocks_simulate_bad_pk_read1",
                  { dbug_modify_key_varchar8(&last_rowkey); });
  rocksdb::Slice rowkey_slice(last_rowkey.ptr(), last_rowkey.length());
  updated_key_slice = &rowkey_slice;
#endif
  return convert_record_from_storage_format(key_def, updated_key_slice,
                                            value_slice, dst);
}

/*
  Decode value slice header
  @param    reader         IN          value slice reader
  @param    pk_def         IN          key definition to decode
  @param    unpack_slice   OUT         unpack info slice
  @return
    0      OK
    other  HA_ERR error code (can be SE-specific)
*/
int Rdb_converter::decode_value_header(
    Rdb_string_reader *reader, const std::shared_ptr<Rdb_key_def> &pk_def,
    rocksdb::Slice *unpack_slice) {
  /* If it's a TTL record, skip the 8 byte TTL value */
  if (pk_def->has_ttl()) {
    const char *ttl_bytes;
    if ((ttl_bytes = reader->read(ROCKSDB_SIZEOF_TTL_RECORD))) {
      memcpy(m_ttl_bytes, ttl_bytes, ROCKSDB_SIZEOF_TTL_RECORD);
    } else {
      return HA_ERR_ROCKSDB_CORRUPT_DATA;
    }
  }

  /* Other fields are decoded from the value */
  if (m_null_bytes_length_in_record &&
      !(m_null_bytes = reader->read(m_null_bytes_length_in_record))) {
    return HA_ERR_ROCKSDB_CORRUPT_DATA;
  }

  if (m_maybe_unpack_info) {
    const char *unpack_info = reader->get_current_ptr();
    if (!unpack_info || !Rdb_key_def::is_unpack_data_tag(unpack_info[0]) ||
        !reader->read(Rdb_key_def::get_unpack_header_size(unpack_info[0]))) {
      return HA_ERR_ROCKSDB_CORRUPT_DATA;
    }

    uint16 unpack_info_len =
        rdb_netbuf_to_uint16(reinterpret_cast<const uchar *>(unpack_info + 1));
    *unpack_slice = rocksdb::Slice(unpack_info, unpack_info_len);

    reader->read(unpack_info_len -
                 Rdb_key_def::get_unpack_header_size(unpack_info[0]));
  }

  return HA_EXIT_SUCCESS;
}

/*
  Convert RocksDb key slice and value slice to Mysql format
  @param      key_def        IN           key definition to decode
  @param      key_slice      IN           RocksDB key slice
  @param      value_slice    IN           RocksDB value slice
  @param      dst            OUT          MySql format address
  @return
    0      OK
    other  HA_ERR error code (can be SE-specific)
*/
int Rdb_converter::convert_record_from_storage_format(
    const std::shared_ptr<Rdb_key_def> &pk_def,
    const rocksdb::Slice *const key_slice,
    const rocksdb::Slice *const value_slice, uchar *const dst) {
  int err = HA_EXIT_SUCCESS;

  Rdb_string_reader value_slice_reader(value_slice);
  rocksdb::Slice unpack_slice;
  err = decode_value_header(&value_slice_reader, pk_def, &unpack_slice);
  if (err != HA_EXIT_SUCCESS) {
    return err;
  }

  /*
    Decode PK fields from the key
  */
  if (m_key_requested) {
    err = pk_def->unpack_record(m_table, dst, key_slice,
                                !unpack_slice.empty() ? &unpack_slice : nullptr,
                                false /* verify_checksum */);
  }
  if (err != HA_EXIT_SUCCESS) {
    return err;
  }

  Rdb_value_field_iterator<Rdb_convert_to_record_value_decoder>
      value_field_iterator(m_table, &value_slice_reader, this, dst);

  // Decode value slices
  while (!value_field_iterator.end_of_fields()) {
    err = value_field_iterator.next();

    if (err != HA_EXIT_SUCCESS) {
      return err;
    }
  }

  if (m_verify_row_debug_checksums) {
    return verify_row_debug_checksum(pk_def, &value_slice_reader, key_slice,
                                     value_slice);
  }
  return HA_EXIT_SUCCESS;
}

/*
  Verify checksum for row
  @param      pk_def   IN     key def
  @param      reader   IN     RocksDB value slice reader
  @param      key      IN     RocksDB key slice
  @param      value    IN     RocksDB value slice
  @return
    0      OK
    other  HA_ERR error code (can be SE-specific)
*/
int Rdb_converter::verify_row_debug_checksum(
    const std::shared_ptr<Rdb_key_def> &pk_def, Rdb_string_reader *reader,
    const rocksdb::Slice *key, const rocksdb::Slice *value) {
  if (reader->remaining_bytes() == RDB_CHECKSUM_CHUNK_SIZE &&
      reader->read(1)[0] == RDB_CHECKSUM_DATA_TAG) {
    uint32_t stored_key_chksum =
        rdb_netbuf_to_uint32((const uchar *)reader->read(RDB_CHECKSUM_SIZE));
    uint32_t stored_val_chksum =
        rdb_netbuf_to_uint32((const uchar *)reader->read(RDB_CHECKSUM_SIZE));

    const uint32_t computed_key_chksum =
        my_core::my_checksum(0, rdb_slice_to_uchar_ptr(key), key->size());
    const uint32_t computed_val_chksum =
        my_core::my_checksum(0, rdb_slice_to_uchar_ptr(value),
                       value->size() - RDB_CHECKSUM_CHUNK_SIZE);

    DBUG_EXECUTE_IF("myrocks_simulate_bad_pk_checksum1", stored_key_chksum++;);

    if (stored_key_chksum != computed_key_chksum) {
      pk_def->report_checksum_mismatch(true, key->data(), key->size());
      return HA_ERR_ROCKSDB_CHECKSUM_MISMATCH;
    }

    DBUG_EXECUTE_IF("myrocks_simulate_bad_pk_checksum2", stored_val_chksum++;);
    if (stored_val_chksum != computed_val_chksum) {
      pk_def->report_checksum_mismatch(false, value->data(), value->size());
      return HA_ERR_ROCKSDB_CHECKSUM_MISMATCH;
    }

    m_row_checksums_checked++;
  }
  if (reader->remaining_bytes()) {
    return HA_ERR_ROCKSDB_CORRUPT_DATA;
  }
  return HA_EXIT_SUCCESS;
}

/**
  Convert record from table->record[0] form into a form that can be written
  into rocksdb.

  @param pk_def               IN        Current key def
  @pk_unpack_info             IN        Unpack info generated during key pack
  @is_update_row              IN        Whether it is update row
  @store_row_debug_checksums  IN        Whether to store checksums
  @param ttl_bytes            IN/OUT    Old ttl value from previous record and
                                        ttl value during current encode
  @is_ttl_bytes_updated       OUT       Whether ttl bytes is updated
  @param value_slice          OUT       Data slice with record data.
*/
int Rdb_converter::encode_value_slice(
    const std::shared_ptr<Rdb_key_def> &pk_def,
    const rocksdb::Slice &pk_packed_slice, Rdb_string_writer *pk_unpack_info,
    bool is_update_row, bool store_row_debug_checksums, char *ttl_bytes,
    bool *is_ttl_bytes_updated, rocksdb::Slice *const value_slice) {
  DBUG_ASSERT(pk_def != nullptr);
  // Currently only primary key will store value slice
  DBUG_ASSERT(pk_def->m_index_type == Rdb_key_def::INDEX_TYPE_PRIMARY ||
              pk_def->m_index_type == Rdb_key_def::INDEX_TYPE_HIDDEN_PRIMARY);
  DBUG_ASSERT_IMP(m_maybe_unpack_info, pk_unpack_info);

  bool has_ttl = pk_def->has_ttl();
  bool has_ttl_column = !pk_def->m_ttl_column.empty();

  m_storage_record.length(0);

  if (has_ttl) {
    /* If it's a TTL record, reserve space for 8 byte TTL value in front. */
    m_storage_record.fill(
        ROCKSDB_SIZEOF_TTL_RECORD + m_null_bytes_length_in_record, 0);
    // NOTE: is_ttl_bytes_updated is only used for update case
    // During update, skip update sk key/values slice iff none of sk fields
    // have changed and ttl bytes isn't changed. see
    // ha_rocksdb::update_write_sk() for more info
    *is_ttl_bytes_updated = false;
    char *const data = const_cast<char *>(m_storage_record.ptr());
    if (has_ttl_column) {
      DBUG_ASSERT(pk_def->get_ttl_field_index() != UINT_MAX);
      Field *const field = m_table->field[pk_def->get_ttl_field_index()];
      DBUG_ASSERT(field->pack_length_in_rec() == ROCKSDB_SIZEOF_TTL_RECORD);
      DBUG_ASSERT(field->real_type() == MYSQL_TYPE_LONGLONG);

      uint64 ts = uint8korr(field->ptr);
#ifndef DBUG_OFF
      ts += rdb_dbug_set_ttl_rec_ts();
#endif
      rdb_netbuf_store_uint64(reinterpret_cast<uchar *>(data), ts);
      if (is_update_row) {
        *is_ttl_bytes_updated =
            memcmp(ttl_bytes, data, ROCKSDB_SIZEOF_TTL_RECORD);
      }
      // Also store in m_ttl_bytes to propagate to update_write_sk
      memcpy(ttl_bytes, data, ROCKSDB_SIZEOF_TTL_RECORD);
    } else {
      /*
        For implicitly generated TTL records we need to copy over the old
        TTL value from the old record in the event of an update. It was stored
        in m_ttl_bytes.

        Otherwise, generate a timestamp using the current time.
      */
      if (is_update_row) {
        memcpy(data, ttl_bytes, sizeof(uint64));
      } else {
        uint64 ts = static_cast<uint64>(std::time(nullptr));
#ifndef DBUG_OFF
        ts += rdb_dbug_set_ttl_rec_ts();
#endif
        rdb_netbuf_store_uint64(reinterpret_cast<uchar *>(data), ts);
        // Also store in m_ttl_bytes to propagate to update_write_sk
        memcpy(ttl_bytes, data, ROCKSDB_SIZEOF_TTL_RECORD);
      }
    }
  } else {
    /* All NULL bits are initially 0 */
    m_storage_record.fill(m_null_bytes_length_in_record, 0);
  }

  // If a primary key may have non-empty unpack_info for certain values,
  // (m_maybe_unpack_info=TRUE), we write the unpack_info block. The block
  // itself was prepared in Rdb_key_def::pack_record.
  if (m_maybe_unpack_info) {
    m_storage_record.append(reinterpret_cast<char *>(pk_unpack_info->ptr()),
                            pk_unpack_info->get_current_pos());
  }
  for (uint i = 0; i < m_table->s->fields; i++) {
    Rdb_field_encoder &encoder = m_encoder_arr[i];
    /* Don't pack decodable PK key parts */
    if (encoder.m_storage_type != Rdb_field_encoder::STORE_ALL) {
      continue;
    }

    Field *const field = m_table->field[i];
    if (encoder.maybe_null()) {
      char *data = const_cast<char *>(m_storage_record.ptr());
      if (has_ttl) {
        data += ROCKSDB_SIZEOF_TTL_RECORD;
      }

      if (field->is_null()) {
        data[encoder.m_null_offset] |= encoder.m_null_mask;
        /* Don't write anything for NULL values */
        continue;
      }
    }

    if (encoder.m_field_type == MYSQL_TYPE_BLOB) {
      my_core::Field_blob *blob =
          reinterpret_cast<my_core::Field_blob *>(field);
      /* Get the number of bytes needed to store length*/
      const uint length_bytes = blob->pack_length() - portable_sizeof_char_ptr;

      /* Store the length of the value */
      m_storage_record.append(reinterpret_cast<char *>(blob->ptr),
                              length_bytes);

      /* Store the blob value itself */
      char *data_ptr;
      memcpy(&data_ptr, blob->ptr + length_bytes, sizeof(uchar **));
      m_storage_record.append(data_ptr, blob->get_length());
    } else if (encoder.m_field_type == MYSQL_TYPE_VARCHAR) {
      Field_varstring *const field_var =
          reinterpret_cast<Field_varstring *>(field);
      uint data_len;
      /* field_var->length_bytes is 1 or 2 */
      if (field_var->length_bytes == 1) {
        data_len = field_var->ptr[0];
      } else {
        DBUG_ASSERT(field_var->length_bytes == 2);
        data_len = uint2korr(field_var->ptr);
      }
      m_storage_record.append(reinterpret_cast<char *>(field_var->ptr),
                              field_var->length_bytes + data_len);
    } else {
      /* Copy the field data */
      const uint len = field->pack_length_in_rec();
      m_storage_record.append(reinterpret_cast<char *>(field->ptr), len);
    }
  }

  if (store_row_debug_checksums) {
    const uint32_t key_crc32 = my_core::my_checksum(
        0, rdb_slice_to_uchar_ptr(&pk_packed_slice), pk_packed_slice.size());
    const uint32_t val_crc32 =
        my_core::my_checksum(0, rdb_mysql_str_to_uchar_str(&m_storage_record),
                       m_storage_record.length());
    uchar key_crc_buf[RDB_CHECKSUM_SIZE];
    uchar val_crc_buf[RDB_CHECKSUM_SIZE];
    rdb_netbuf_store_uint32(key_crc_buf, key_crc32);
    rdb_netbuf_store_uint32(val_crc_buf, val_crc32);
    m_storage_record.append((const char *)&RDB_CHECKSUM_DATA_TAG, 1);
    m_storage_record.append((const char *)key_crc_buf, RDB_CHECKSUM_SIZE);
    m_storage_record.append((const char *)val_crc_buf, RDB_CHECKSUM_SIZE);
  }

  *value_slice =
      rocksdb::Slice(m_storage_record.ptr(), m_storage_record.length());

  return HA_EXIT_SUCCESS;
}
}  // namespace myrocks