summaryrefslogtreecommitdiffstats
path: root/sql/create_options.cc
blob: cea5d7af95081e85322aad221064ade6da711764 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
/* Copyright (C) 2010, 2020, 2021, MariaDB Corporation.

   This program is free software; you can redistribute it and/or modify
   it under 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */

/**
  @file

  Engine defined options of tables/fields/keys in CREATE/ALTER TABLE.
*/

#include "mariadb.h"
#include "create_options.h"
#include "partition_info.h"
#include <my_getopt.h>
#include "set_var.h"

#define FRM_QUOTED_VALUE 0x8000U

/**
  Links this item to the given list end

  @param start           The list beginning or NULL
  @param end             The list last element or does not matter
*/

void engine_option_value::link(engine_option_value **start,
                               engine_option_value **end)
{
  DBUG_ENTER("engine_option_value::link");
  DBUG_PRINT("enter", ("name: '%s' (%u)  value: '%s' (%u)",
                       name.str, (uint) name.length,
                       value.str, (uint) value.length));
  engine_option_value *opt;
  /* check duplicates to avoid writing them to frm*/
  for(opt= *start;
      opt && ((opt->parsed && !opt->value.str) ||
              system_charset_info->strnncoll(name.str, name.length,
                                             opt->name.str, opt->name.length));
      opt= opt->next) /* no-op */;
  if (opt)
  {
    opt->value.str= NULL;       /* remove previous value */
    opt->parsed= TRUE;          /* and don't issue warnings for it anymore */
  }
  /*
    Add this option to the end of the list

    @note: We add even if it is opt->value.str == NULL because it can be
    ALTER TABLE to remove the option.
  */
  if (*start)
  {
    (*end)->next= this;
    *end= this;
  }
  else
  {
    /*
      note that is *start == 0, the value of *end does not matter,
      it can be uninitialized.
    */
    *start= *end= this;
  }
  DBUG_VOID_RETURN;
}

static bool report_wrong_value(THD *thd, const char *name, const char *val,
                               bool suppress_warning)
{
  if (suppress_warning)
    return 0;

  if (!(thd->variables.sql_mode & MODE_IGNORE_BAD_TABLE_OPTIONS) &&
      !thd->slave_thread)
  {
    my_error(ER_BAD_OPTION_VALUE, MYF(0), val, name);
    return 1;
  }

  push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN, ER_BAD_OPTION_VALUE,
                      ER_THD(thd, ER_BAD_OPTION_VALUE), val, name);
  return 0;
}

static bool report_unknown_option(THD *thd, engine_option_value *val,
                                  bool suppress_warning)
{
  DBUG_ENTER("report_unknown_option");

  if (val->parsed || suppress_warning || thd->slave_thread)
  {
    DBUG_PRINT("info", ("parsed => exiting"));
    DBUG_RETURN(FALSE);
  }

  if (!(thd->variables.sql_mode & MODE_IGNORE_BAD_TABLE_OPTIONS))
  {
    my_error(ER_UNKNOWN_OPTION, MYF(0), val->name.str);
    DBUG_RETURN(TRUE);
  }

  push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
                      ER_UNKNOWN_OPTION, ER_THD(thd, ER_UNKNOWN_OPTION),
                      val->name.str);
  DBUG_RETURN(FALSE);
}

#define value_ptr(STRUCT,OPT)    ((char*)(STRUCT) + (OPT)->offset)

static bool set_one_value(ha_create_table_option *opt,
                          THD *thd, const LEX_CSTRING *value, void *base,
                          bool suppress_warning,
                          MEM_ROOT *root)
{
  DBUG_ENTER("set_one_value");
  DBUG_PRINT("enter", ("opt: %p type: %u name '%s' value: '%s'",
                       opt,
                       opt->type, opt->name,
                       (value->str ? value->str : "<DEFAULT>")));
  switch (opt->type)
  {
  case HA_OPTION_TYPE_SYSVAR:
    // HA_OPTION_TYPE_SYSVAR's are replaced in resolve_sysvars()
    break; // to DBUG_ASSERT(0)
  case HA_OPTION_TYPE_ULL:
    {
      ulonglong *val= (ulonglong*)value_ptr(base, opt);
      if (!value->str)
      {
        *val= opt->def_value;
        DBUG_RETURN(0);
      }

      my_option optp=
        { opt->name, 1, 0, (uchar **)val, 0, 0, GET_ULL,
          REQUIRED_ARG, (longlong)opt->def_value, (longlong)opt->min_value,
          opt->max_value, 0, (long) opt->block_size, 0};

      ulonglong orig_val= strtoull(value->str, NULL, 10);
      my_bool unused;
      *val= orig_val;
      *val= getopt_ull_limit_value(*val, &optp, &unused);
      if (*val == orig_val)
        DBUG_RETURN(0);

      DBUG_RETURN(report_wrong_value(thd, opt->name, value->str,
                                     suppress_warning));
    }
  case HA_OPTION_TYPE_STRING:
    {
      char **val= (char **)value_ptr(base, opt);
      if (!value->str)
      {
        *val= 0;
        DBUG_RETURN(0);
      }

      if (!(*val= strmake_root(root, value->str, value->length)))
        DBUG_RETURN(1);
      DBUG_RETURN(0);
    }
  case HA_OPTION_TYPE_ENUM:
    {
      uint *val= (uint *)value_ptr(base, opt), num;

      *val= (uint) opt->def_value;
      if (!value->str)
        DBUG_RETURN(0);

      const char *start= opt->values, *end;

      num= 0;
      while (*start)
      {
        for (end=start;
             *end && *end != ',';
             end++) /* no-op */;
        if (!system_charset_info->strnncoll(start, end-start,
                                            value->str, value->length))
        {
          *val= num;
          DBUG_RETURN(0);
        }
        if (*end)
          end++;
        start= end;
        num++;
      }

      DBUG_RETURN(report_wrong_value(thd, opt->name, value->str,
                                     suppress_warning));
    }
  case HA_OPTION_TYPE_BOOL:
    {
      bool *val= (bool *)value_ptr(base, opt);
      *val= opt->def_value;

      if (!value->str)
        DBUG_RETURN(0);

      if (!system_charset_info->strnncoll("NO", 2, value->str, value->length) ||
          !system_charset_info->strnncoll("OFF", 3, value->str, value->length) ||
          !system_charset_info->strnncoll("0", 1, value->str, value->length))
      {
        *val= FALSE;
        DBUG_RETURN(FALSE);
      }

      if (!system_charset_info->strnncoll("YES", 3, value->str, value->length) ||
          !system_charset_info->strnncoll("ON", 2, value->str, value->length) ||
          !system_charset_info->strnncoll("1", 1, value->str, value->length))
      {
        *val= TRUE;
        DBUG_RETURN(FALSE);
      }

      DBUG_RETURN(report_wrong_value(thd, opt->name, value->str,
                                     suppress_warning));
    }
  }
  DBUG_ASSERT(0);
  my_error(ER_UNKNOWN_ERROR, MYF(0));
  DBUG_RETURN(1);
}

static const size_t ha_option_type_sizeof[]=
{ sizeof(ulonglong), sizeof(char *), sizeof(uint), sizeof(bool)};

/**
  Creates option structure and parses list of options in it

  @param thd              thread handler
  @param option_struct    where to store pointer on the option struct
  @param option_list      list of options given by user
  @param rules            list of option description by engine
  @param suppress_warning second parse so we do not need warnings
  @param root             MEM_ROOT where allocate memory

  @retval TRUE  Error
  @retval FALSE OK
*/

bool parse_option_list(THD* thd, handlerton *hton, void *option_struct_arg,
                       engine_option_value **option_list,
                       ha_create_table_option *rules,
                       bool suppress_warning, MEM_ROOT *root)
{
  ha_create_table_option *opt;
  size_t option_struct_size= 0;
  engine_option_value *val, *last;
  void **option_struct= (void**)option_struct_arg;
  DBUG_ENTER("parse_option_list");
  DBUG_PRINT("enter",
             ("struct: %p list: %p rules: %p suppress_warning: %u root: %p",
              *option_struct, *option_list, rules,
              (uint) suppress_warning, root));

  if (rules)
  {
    for (opt= rules; opt->name; opt++)
      set_if_bigger(option_struct_size, opt->offset +
                    ha_option_type_sizeof[opt->type]);

    *option_struct= alloc_root(root, option_struct_size);
  }

  for (opt= rules; rules && opt->name; opt++)
  {
    bool seen=false;
    for (val= *option_list; val; val= val->next)
    {
      last= val;
      if (system_charset_info->strnncoll(opt->name, opt->name_length,
                                         val->name.str, val->name.length))
        continue;

      /* skip duplicates (see engine_option_value constructor above) */
      if (val->parsed && !val->value.str)
        continue;

      if (set_one_value(opt, thd, &val->value,
                        *option_struct, suppress_warning || val->parsed, root))
        DBUG_RETURN(TRUE);
      val->parsed= true;
      seen=true;
      break;
    }
    if (!seen || (opt->var && !last->value.str))
    {
      LEX_CSTRING default_val= null_clex_str;

      /*
        Okay, here's the logic for sysvar options:
        1. When we parse CREATE TABLE and sysvar option was not explicitly
           mentioned we add it to the list as if it was specified with the
           *current* value of the underlying sysvar.
        2. But only if the underlying sysvar value is different from the
           sysvar's default.
        3. If it's ALTER TABLE or CREATE_SEQUENCE and the sysvar option was
           not explicitly mentioned - do nothing, do not add it to the list.
        4. But if it was ALTER TABLE with sysvar option = DEFAULT, we
           add it to the list (under the same condition #2).
        5. If we're here parsing the option list from the .frm file
           for a normal open_table() and the sysvar option was not there -
           do not add it to the list (makes no sense anyway) and
           use the *default* value of the underlying sysvar. Because
           sysvar value can change, but it should not affect existing tables.
        This is how it's implemented: the current sysvar value is added
        to the list if suppress_warning is FALSE (meaning a table is created,
        that is CREATE TABLE or ALTER TABLE) and it's actually a CREATE TABLE
        command or it's an ALTER TABLE and the option was seen (=DEFAULT).

        Note that if the option was set explicitly (not =DEFAULT) it wouldn't
        have passes the if() condition above.
      */
      if (!suppress_warning && opt->var &&
          (thd->lex->sql_command == SQLCOM_CREATE_TABLE || seen))
      {
        // take a value from the variable and add it to the list
        sys_var *sysvar= find_hton_sysvar(hton, opt->var);
        DBUG_ASSERT(sysvar);

        if (!sysvar->session_is_default(thd))
        {
          char buf[256];
          String sbuf(buf, sizeof(buf), system_charset_info), *str;
          if ((str= sysvar->val_str(&sbuf, thd, OPT_SESSION, &null_clex_str)))
          {
            LEX_CSTRING name= { opt->name, opt->name_length };
            default_val.str= strmake_root(root, str->ptr(), str->length());
            default_val.length= str->length();
            val= new (root) engine_option_value(
                name, default_val, opt->type != HA_OPTION_TYPE_ULL);
            if (!val)
              DBUG_RETURN(TRUE);
            val->link(option_list, &last);
            val->parsed= true;
          }
        }
      }
      set_one_value(opt, thd, &default_val, *option_struct,
                    suppress_warning, root);
    }
  }

  for (val= *option_list; val; val= val->next)
  {
    if (report_unknown_option(thd, val, suppress_warning))
      DBUG_RETURN(TRUE);
    val->parsed= true;
  }

  DBUG_RETURN(FALSE);
}


/**
  Resolves all HA_OPTION_TYPE_SYSVAR elements.

  This is done when an engine is loaded.
*/
static bool resolve_sysvars(handlerton *hton, ha_create_table_option *rules)
{
  for (ha_create_table_option *opt= rules; rules && opt->name; opt++)
  {
    if (opt->type == HA_OPTION_TYPE_SYSVAR)
    {
      struct my_option optp;
      plugin_opt_set_limits(&optp, opt->var);
      switch(optp.var_type) {
      case GET_ULL:
      case GET_ULONG:
      case GET_UINT:
        opt->type= HA_OPTION_TYPE_ULL;
        opt->def_value= (ulonglong)optp.def_value;
        opt->min_value= (ulonglong)optp.min_value;
        opt->max_value= (ulonglong)optp.max_value;
        opt->block_size= (ulonglong)optp.block_size;
        break;
      case GET_STR:
      case GET_STR_ALLOC:
        opt->type= HA_OPTION_TYPE_STRING;
        break;
      case GET_BOOL:
        opt->type= HA_OPTION_TYPE_BOOL;
        opt->def_value= optp.def_value;
        break;
      case GET_ENUM:
      {
        opt->type= HA_OPTION_TYPE_ENUM;
        opt->def_value= optp.def_value;

        char buf[256];
        String str(buf, sizeof(buf), system_charset_info);
        str.length(0);
        for (const char **s= optp.typelib->type_names; *s; s++)
        {
          if (str.append(*s, strlen(*s)) || str.append(','))
            return 1;
        }
        DBUG_ASSERT(str.length());
        opt->values= my_strndup(PSI_INSTRUMENT_ME, str.ptr(), str.length()-1, MYF(MY_WME));
        if (!opt->values)
          return 1;
        break;
      }
      default:
        DBUG_ASSERT(0);
      }
    }
  }
  return 0;
}

bool resolve_sysvar_table_options(handlerton *hton)
{
  return resolve_sysvars(hton, hton->table_options) ||
         resolve_sysvars(hton, hton->field_options) ||
         resolve_sysvars(hton, hton->index_options);
}

/*
  Restore HA_OPTION_TYPE_SYSVAR options back as they were
  before resolve_sysvars().

  This is done when the engine is unloaded, so that we could
  call resolve_sysvars() if the engine is installed again.
*/
static void free_sysvars(handlerton *hton, ha_create_table_option *rules)
{
  for (ha_create_table_option *opt= rules; rules && opt->name; opt++)
  {
    if (opt->var)
    {
      my_free(const_cast<char*>(opt->values));
      opt->type= HA_OPTION_TYPE_SYSVAR;
      opt->def_value= 0;
      opt->min_value= 0;
      opt->max_value= 0;
      opt->block_size= 0;
      opt->values= 0;
    }
  }
}

void free_sysvar_table_options(handlerton *hton)
{
  free_sysvars(hton, hton->table_options);
  free_sysvars(hton, hton->field_options);
  free_sysvars(hton, hton->index_options);
}


/**
  Parses all table/fields/keys options

  @param thd             thread handler
  @param file            handler of the table
  @parem share           descriptor of the table

  @retval TRUE  Error
  @retval FALSE OK
*/

bool parse_engine_table_options(THD *thd, handlerton *ht, TABLE_SHARE *share)
{
  MEM_ROOT *root= &share->mem_root;
  DBUG_ENTER("parse_engine_table_options");

  if (parse_option_list(thd, ht, &share->option_struct, & share->option_list,
                        ht->table_options, TRUE, root))
    DBUG_RETURN(TRUE);

  for (Field **field= share->field; *field; field++)
  {
    if (parse_option_list(thd, ht, &(*field)->option_struct,
                          & (*field)->option_list,
                          ht->field_options, TRUE, root))
      DBUG_RETURN(TRUE);
  }

  for (uint index= 0; index < share->keys; index ++)
  {
    if (parse_option_list(thd, ht, &share->key_info[index].option_struct,
                          & share->key_info[index].option_list,
                          ht->index_options, TRUE, root))
      DBUG_RETURN(TRUE);
  }

  DBUG_RETURN(FALSE);
}

#ifdef WITH_PARTITION_STORAGE_ENGINE
/**
  Parses engine-defined partition options

  @param [in] thd   thread handler
  @parem [in] table table with part_info

  @retval TRUE  Error
  @retval FALSE OK

  In the case of ALTER TABLE statements, table->part_info is set up
  by mysql_unpack_partition(). So, one should not call the present
  function before the call of mysql_unpack_partition().
*/
bool parse_engine_part_options(THD *thd, TABLE *table)
{
  MEM_ROOT *root= &table->mem_root;
  TABLE_SHARE *share= table->s;
  partition_info *part_info= table->part_info;
  engine_option_value *tmp_option_list;
  handlerton *ht;
  DBUG_ENTER("parse_engine_part_options");

  if (!part_info)
    DBUG_RETURN(FALSE);

  List_iterator<partition_element> it(part_info->partitions);
  while (partition_element *part_elem= it++)
  {
    if (merge_engine_options(share->option_list, part_elem->option_list,
                             &tmp_option_list, root))
      DBUG_RETURN(TRUE);

    if (!part_info->is_sub_partitioned())
    {
      ht= part_elem->engine_type;
      if (parse_option_list(thd, ht, &part_elem->option_struct,
                            &tmp_option_list, ht->table_options, TRUE, root))
        DBUG_RETURN(TRUE);
    }
    else
    {
      List_iterator<partition_element> sub_it(part_elem->subpartitions);
      while (partition_element *sub_part_elem= sub_it++)
      {
        ht= sub_part_elem->engine_type;
        if (parse_option_list(thd, ht, &sub_part_elem->option_struct,
                              &tmp_option_list, ht->table_options, TRUE, root))
          DBUG_RETURN(TRUE);
      }
    }
  }
  DBUG_RETURN(FALSE);
}
#endif

bool engine_options_differ(void *old_struct, void *new_struct,
                           ha_create_table_option *rules)
{
  ha_create_table_option *opt;
  for (opt= rules; rules && opt->name; opt++)
  {
    char **old_val= (char**)value_ptr(old_struct, opt);
    char **new_val= (char**)value_ptr(new_struct, opt);
    int neq;
    if (opt->type == HA_OPTION_TYPE_STRING)
      neq= (*old_val && *new_val) ? strcmp(*old_val, *new_val) :  *old_val != *new_val;
    else
      neq= memcmp(old_val, new_val, ha_option_type_sizeof[opt->type]);
    if (neq)
      return true;
  }
  return false;
}


/**
  Returns representation length of key and value in the frm file
*/

uint engine_option_value::frm_length()
{
  /*
    1 byte  - name length
    2 bytes - value length

    if value.str is NULL, this option is not written to frm (=DEFAULT)
  */
  return value.str ? (uint)(1 + name.length + 2 + value.length) : 0;
}


/**
  Returns length of representation of option list in the frm file
*/

static uint option_list_frm_length(engine_option_value *opt)
{
  uint res= 0;

  for (; opt; opt= opt->next)
    res+= opt->frm_length();

  return res;
}


/**
  Calculates length of options image in the .frm

  @param table_option_list list of table options
  @param create_fields     field descriptors list
  @param keys              number of keys
  @param key_info          array of key descriptors

  @returns length of image in frm
*/

uint engine_table_options_frm_length(engine_option_value *table_option_list,
                                     List<Create_field> &create_fields,
                                     uint keys, KEY *key_info)
{
  List_iterator<Create_field> it(create_fields);
  Create_field *field;
  uint res, index;
  DBUG_ENTER("engine_table_options_frm_length");

  res= option_list_frm_length(table_option_list);

  while ((field= it++))
    res+= option_list_frm_length(field->option_list);

  for (index= 0; index < keys; index++, key_info++)
    res+= option_list_frm_length(key_info->option_list);

  /*
    if there's at least one option somewhere (res > 0)
    we write option lists for all fields and keys, zero-terminated.
    If there're no options we write nothing at all (backward compatibility)
  */
  DBUG_RETURN(res ? res + 1 + create_fields.elements + keys : 0);
}


/**
  Writes image of the key and value to the frm image buffer

  @param buff            pointer to the buffer free space beginning

  @returns pointer to byte after last recorded in the buffer
*/

uchar *engine_option_value::frm_image(uchar *buff)
{
  if (value.str)
  {
    DBUG_ASSERT(name.length <= 0xff);
    *buff++= (uchar)name.length;
    memcpy(buff, name.str, name.length);
    buff+= name.length;
    int2store(buff, value.length | (quoted_value ? FRM_QUOTED_VALUE : 0));
    buff+= 2;
    memcpy(buff, (const uchar *) value.str, value.length);
    buff+= value.length;
  }
  return buff;
}

/**
  Writes image of the key and value to the frm image buffer

  @param buff            pointer to the buffer to store the options in
  @param opt             list of options;

  @returns pointer to the end of the stored data in the buffer
*/
static uchar *option_list_frm_image(uchar *buff, engine_option_value *opt)
{
  for (; opt; opt= opt->next)
    buff= opt->frm_image(buff);

  *buff++= 0;
  return buff;
}


/**
  Writes options image in the .frm buffer

  @param buff              pointer to the buffer
  @param table_option_list list of table options
  @param create_fields     field descriptors list
  @param keys              number of keys
  @param key_info          array of key descriptors

  @returns pointer to byte after last recorded in the buffer
*/

uchar *engine_table_options_frm_image(uchar *buff,
                                      engine_option_value *table_option_list,
                                      List<Create_field> &create_fields,
                                      uint keys, KEY *key_info)
{
  List_iterator<Create_field> it(create_fields);
  Create_field *field;
  KEY *key_info_end= key_info + keys;
  DBUG_ENTER("engine_table_options_frm_image");

  buff= option_list_frm_image(buff, table_option_list);

  while ((field= it++))
    buff= option_list_frm_image(buff, field->option_list);

  while (key_info < key_info_end)
    buff= option_list_frm_image(buff, (key_info++)->option_list);

  DBUG_RETURN(buff);
}

/**
  Reads name and value from buffer, then link it in the list

  @param buff            the buffer to read from
  @param start           The list beginning or NULL
  @param end             The list last element or does not matter
  @param root            MEM_ROOT for allocating

  @returns pointer to byte after last recorded in the buffer
*/
uchar *engine_option_value::frm_read(const uchar *buff, const uchar *buff_end,
                                     engine_option_value **start,
                                     engine_option_value **end, MEM_ROOT *root)
{
  LEX_CSTRING name, value;
  uint len;
#define need_buff(N)  if (buff + (N) >= buff_end) return NULL

  need_buff(3);
  name.length= buff[0];
  buff++;
  need_buff(name.length + 2);
  if (!(name.str= strmake_root(root, (const char*)buff, name.length)))
    return NULL;
  buff+= name.length;
  len= uint2korr(buff);
  value.length= len & ~FRM_QUOTED_VALUE;
  buff+= 2;
  need_buff(value.length);
  if (!(value.str= strmake_root(root, (const char*)buff, value.length)))
    return NULL;
  buff+= value.length;

  engine_option_value *ptr=
      new (root) engine_option_value(name, value, len & FRM_QUOTED_VALUE);
  if (!ptr)
    return NULL;
  ptr->link(start, end);

  return (uchar *)buff;
}


/**
  Reads options from this buffer

  @param buff            the buffer to read from
  @param length          buffer length
  @param share           table descriptor
  @param root            MEM_ROOT for allocating

  @retval TRUE  Error
  @retval FALSE OK
*/

bool engine_table_options_frm_read(const uchar *buff, size_t length,
                                   TABLE_SHARE *share)
{
  const uchar *buff_end= buff + length;
  engine_option_value *UNINIT_VAR(end);
  MEM_ROOT *root= &share->mem_root;
  uint count;
  DBUG_ENTER("engine_table_options_frm_read");

  while (buff < buff_end && *buff)
  {
    if (!(buff= engine_option_value::frm_read(buff, buff_end,
                                              &share->option_list, &end, root)))
      DBUG_RETURN(TRUE);
  }
  buff++;

  for (count=0; count < share->fields; count++)
  {
    while (buff < buff_end && *buff)
    {
      if (!(buff= engine_option_value::frm_read(buff, buff_end,
                                                &share->field[count]->option_list,
                                                &end, root)))
        DBUG_RETURN(TRUE);
    }
    buff++;
  }

  for (count=0; count < share->keys; count++)
  {
    while (buff < buff_end && *buff)
    {
      if (!(buff= engine_option_value::frm_read(buff, buff_end,
                                                &share->key_info[count].option_list,
                                                &end, root)))
        DBUG_RETURN(TRUE);
    }
    buff++;
  }

  if (buff < buff_end)
    sql_print_warning("Table '%s' was created in a later MariaDB version - "
                      "unknown table attributes were ignored",
                      share->table_name.str);

  DBUG_RETURN(buff > buff_end);
}

/**
  Merges two lists of engine_option_value's with duplicate removal.

  @param [in] source  option list
  @param [in] changes option list whose options overwrite source's
  @param [out] out    new option list created by merging given two
  @param [in] root    MEM_ROOT for allocating memory

  @retval TRUE  Error
  @retval FALSE OK
*/
bool merge_engine_options(engine_option_value *source,
                          engine_option_value *changes,
                          engine_option_value **out, MEM_ROOT *root)
{
  engine_option_value *UNINIT_VAR(end), *opt, *opt_copy;
  *out= 0;
  DBUG_ENTER("merge_engine_options");

  /* Create copy of source list */
  for (opt= source; opt; opt= opt->next)
  {
    opt_copy= new (root) engine_option_value(opt);
    if (!opt_copy)
      DBUG_RETURN(TRUE);
    opt_copy->link(out, &end);
  }

  for (opt= changes; opt; opt= opt->next)
  {
    opt_copy= new (root) engine_option_value(opt);
    if (!opt_copy)
      DBUG_RETURN(TRUE);
    opt_copy->link(out, &end);
  }
  DBUG_RETURN(FALSE);
}

bool is_engine_option_known(engine_option_value *opt,
                            ha_create_table_option *rules)
{
  if (!rules)
    return false;

  for (; rules->name; rules++)
  {
      if (!system_charset_info->strnncoll(rules->name, rules->name_length,
                                          opt->name.str, opt->name.length))
        return true;
  }
  return false;
}