sql_class.cc 42.8 KB
Newer Older
unknown's avatar
unknown committed
1
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
unknown's avatar
unknown committed
2

unknown's avatar
unknown committed
3 4 5 6
   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; either version 2 of the License, or
   (at your option) any later version.
unknown's avatar
unknown committed
7

unknown's avatar
unknown committed
8 9 10 11
   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.
unknown's avatar
unknown committed
12

unknown's avatar
unknown committed
13 14 15 16 17 18 19 20 21 22 23 24
   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 */


/*****************************************************************************
**
** This file implements classes defined in sql_class.h
** Especially the classes to handle a result from a select
**
*****************************************************************************/

25
#ifdef USE_PRAGMA_IMPLEMENTATION
unknown's avatar
unknown committed
26 27
#pragma implementation				// gcc: Class implementation
#endif
28 29

#include "mysql_priv.h"
unknown's avatar
unknown committed
30 31
#include <m_ctype.h>
#include <sys/stat.h>
32
#include <thr_alarm.h>
unknown's avatar
unknown committed
33 34 35
#ifdef	__WIN__
#include <io.h>
#endif
36
#include <mysys_err.h>
unknown's avatar
unknown committed
37

38 39 40 41 42 43
/*
  The following is used to initialise Table_ident with a internal
  table name
*/
char internal_table_name[2]= "*";

44

unknown's avatar
unknown committed
45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64
/*****************************************************************************
** Instansiate templates
*****************************************************************************/

#ifdef __GNUC__
/* Used templates */
template class List<Key>;
template class List_iterator<Key>;
template class List<key_part_spec>;
template class List_iterator<key_part_spec>;
template class List<Alter_drop>;
template class List_iterator<Alter_drop>;
template class List<Alter_column>;
template class List_iterator<Alter_column>;
#endif

/****************************************************************************
** User variables
****************************************************************************/

65 66
extern "C" byte *get_var_key(user_var_entry *entry, uint *length,
			     my_bool not_used __attribute__((unused)))
unknown's avatar
unknown committed
67 68 69 70 71
{
  *length=(uint) entry->name.length;
  return (byte*) entry->name.str;
}

72
extern "C" void free_user_var(user_var_entry *entry)
unknown's avatar
unknown committed
73 74 75 76 77 78 79
{
  char *pos= (char*) entry+ALIGN_SIZE(sizeof(*entry));
  if (entry->value && entry->value != pos)
    my_free(entry->value, MYF(0));
  my_free((char*) entry,MYF(0));
}

80 81 82 83 84
bool key_part_spec::operator==(const key_part_spec& other) const
{
  return length == other.length && !strcmp(field_name, other.field_name);
}

85 86

/*
87
  Test if a foreign key (= generated key) is a prefix of the given key
88 89 90 91 92 93 94 95 96 97 98 99 100 101
  (ignoring key name, key type and order of columns)

  NOTES:
    This is only used to test if an index for a FOREIGN KEY exists

  IMPLEMENTATION
    We only compare field names

  RETURN
    0	Generated key is a prefix of other key
    1	Not equal
*/

bool foreign_key_prefix(Key *a, Key *b)
102
{
103 104 105 106
  /* Ensure that 'a' is the generated key */
  if (a->generated)
  {
    if (b->generated && a->columns.elements > b->columns.elements)
107
      swap_variables(Key*, a, b);               // Put shorter key in 'a'
108 109
  }
  else
110
  {
111 112
    if (!b->generated)
      return TRUE;                              // No foreign key
113
    swap_variables(Key*, a, b);                 // Put generated key in 'a'
114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129
  }

  /* Test if 'a' is a prefix of 'b' */
  if (a->columns.elements > b->columns.elements)
    return TRUE;                                // Can't be prefix

  List_iterator<key_part_spec> col_it1(a->columns);
  List_iterator<key_part_spec> col_it2(b->columns);
  const key_part_spec *col1, *col2;

#ifdef ENABLE_WHEN_INNODB_CAN_HANDLE_SWAPED_FOREIGN_KEY_COLUMNS
  while ((col1= col_it1++))
  {
    bool found= 0;
    col_it2.rewind();
    while ((col2= col_it2++))
130
    {
131 132 133 134 135
      if (*col1 == *col2)
      {
        found= TRUE;
	break;
      }
136
    }
137 138 139 140 141 142 143 144 145 146
    if (!found)
      return TRUE;                              // Error
  }
  return FALSE;                                 // Is prefix
#else
  while ((col1= col_it1++))
  {
    col2= col_it2++;
    if (!(*col1 == *col2))
      return TRUE;
147
  }
148 149
  return FALSE;                                 // Is prefix
#endif
150 151 152
}


unknown's avatar
unknown committed
153 154 155 156
/****************************************************************************
** Thread specific functions
****************************************************************************/

157 158 159 160 161
THD::THD()
  :user_time(0), global_read_lock(0), is_fatal_error(0),
   last_insert_id_used(0),
   insert_id_used(0), rand_used(0), time_zone_used(0),
   in_lock_tables(0), bootstrap(0)
unknown's avatar
unknown committed
162
{
163
  current_arena= this;
164
  host= user= priv_user= db= ip=0;
165
  host_or_ip= "connecting host";
unknown's avatar
unknown committed
166 167
  locked=some_tables_deleted=no_errors=password= 0;
  killed=0;
unknown's avatar
unknown committed
168
  query_start_used= 0;
169
  count_cuted_fields= CHECK_FIELD_IGNORE;
170
  db_length= col_access= 0;
unknown's avatar
unknown committed
171
  query_error= tmp_table_used= 0;
unknown's avatar
unknown committed
172
  next_insert_id=last_insert_id=0;
173
  open_tables= temporary_tables= handler_tables= derived_tables= 0;
174
  hash_clear(&handler_tables_hash);
unknown's avatar
unknown committed
175 176
  tmp_table=0;
  lock=locked_tables=0;
177
  used_tables=0;
178
  cuted_fields= sent_row_count= 0L;
179
  limit_found_rows= 0;
180
  statement_id_counter= 0UL;
181
  // Must be reset to handle error with THD's created for init of mysqld
182
  lex->current_select= 0;
unknown's avatar
unknown committed
183
  start_time=(time_t) 0;
unknown's avatar
unknown committed
184
  current_linfo =  0;
185
  slave_thread = 0;
unknown's avatar
unknown committed
186
  variables.pseudo_thread_id= 0;
187
  one_shot_set= 0;
188
  file_id = 0;
189
  query_id= 0;
190
  warn_id= 0;
191
  db_charset= global_system_variables.collation_database;
unknown's avatar
unknown committed
192
  mysys_var=0;
193 194
#ifndef DBUG_OFF
  dbug_sentry=THD_SENTRY_MAGIC;
195 196
#endif
#ifndef EMBEDDED_LIBRARY  
unknown's avatar
unknown committed
197
  net.vio=0;
198
#endif
199
  net.last_error[0]=0;				// If error on boot
200
  client_capabilities= 0;                       // minimalistic client
unknown's avatar
unknown committed
201
  ull=0;
unknown's avatar
unknown committed
202
  system_thread=cleanup_done=0;
203
  peer_port= 0;					// For SHOW PROCESSLIST
204
  transaction.changed_tables = 0;
unknown's avatar
unknown committed
205 206 207 208 209 210
#ifdef	__WIN__
  real_id = 0;
#endif
#ifdef SIGNAL_WITH_VIO_CLOSE
  active_vio = 0;
#endif  
211
  pthread_mutex_init(&LOCK_delete, MY_MUTEX_INIT_FAST);
unknown's avatar
unknown committed
212 213 214 215 216

  /* Variables with default values */
  proc_info="login";
  where="field list";
  server_id = ::server_id;
217
  slave_net = 0;
unknown's avatar
unknown committed
218
  command=COM_CONNECT;
unknown's avatar
unknown committed
219
#ifndef NO_EMBEDDED_ACCESS_CHECKS
unknown's avatar
unknown committed
220
  db_access=NO_ACCESS;
unknown's avatar
unknown committed
221
#endif
222
  version=refresh_version;			// For boot
unknown's avatar
unknown committed
223
  *scramble= '\0';
unknown's avatar
unknown committed
224

unknown's avatar
unknown committed
225
  init();
unknown's avatar
unknown committed
226
  /* Initialize sub structures */
227
  init_sql_alloc(&warn_root, WARN_ALLOC_BLOCK_SIZE, WARN_ALLOC_PREALLOC_SIZE);
228
  user_connect=(USER_CONN *)0;
unknown's avatar
unknown committed
229
  hash_init(&user_vars, &my_charset_bin, USER_VARS_HASH_SIZE, 0, 0,
unknown's avatar
unknown committed
230
	    (hash_get_key) get_var_key,
231
	    (hash_free_key) free_user_var,0);
232

unknown's avatar
unknown committed
233 234 235 236 237 238 239 240
  /* For user vars replication*/
  if (opt_bin_log)
    my_init_dynamic_array(&user_var_events,
			  sizeof(BINLOG_USER_VAR_EVENT *),
			  16,
			  16);
  else
    bzero((char*) &user_var_events, sizeof(user_var_events));
241

242 243 244 245 246
  /* Protocol */
  protocol= &protocol_simple;			// Default protocol
  protocol_simple.init(this);
  protocol_prep.init(this);

unknown's avatar
unknown committed
247
  tablespace_op=FALSE;
248
#ifdef USING_TRANSACTIONS
unknown's avatar
unknown committed
249
  bzero((char*) &transaction,sizeof(transaction));
250 251 252 253 254
  /*
    Binlog is always open (if needed) before a THD is created (including
    bootstrap).
  */
  if (opt_using_transactions && mysql_bin_log.is_open())
255 256 257 258 259 260 261
  {
    if (open_cached_file(&transaction.trans_log,
			 mysql_tmpdir, LOG_PREFIX, binlog_cache_size,
			 MYF(MY_WME)))
      killed=1;
    transaction.trans_log.end_of_file= max_binlog_cache_size;
  }
262
#endif
263
  init_sql_alloc(&transaction.mem_root, ALLOC_ROOT_MIN_BLOCK_SIZE, 0);
264
  {
unknown's avatar
unknown committed
265
    ulong tmp=sql_rnd_with_mutex();
266
    randominit(&rand, tmp + (ulong) &rand, tmp + (ulong) ::query_id);
267
  }
unknown's avatar
unknown committed
268 269
}

unknown's avatar
unknown committed
270 271 272 273 274 275 276

/*
  Init common variables that has to be reset on start and on change_user
*/

void THD::init(void)
{
277 278
  pthread_mutex_lock(&LOCK_global_system_variables);
  variables= global_system_variables;
279 280 281 282 283 284
  variables.time_format= date_time_format_copy((THD*) 0,
					       variables.time_format);
  variables.date_format= date_time_format_copy((THD*) 0,
					       variables.date_format);
  variables.datetime_format= date_time_format_copy((THD*) 0,
						   variables.datetime_format);
285 286 287
#ifdef HAVE_NDBCLUSTER_DB
  variables.ndb_use_transactions= 1;
#endif
288
  pthread_mutex_unlock(&LOCK_global_system_variables);
unknown's avatar
unknown committed
289 290 291
  server_status= SERVER_STATUS_AUTOCOMMIT;
  options= thd_startup_options;
  open_options=ha_open_options;
292 293 294
  update_lock_default= (variables.low_priority_updates ?
			TL_WRITE_LOW_PRIORITY :
			TL_WRITE);
unknown's avatar
unknown committed
295
  session_tx_isolation= (enum_tx_isolation) variables.tx_isolation;
296 297 298
  warn_list.empty();
  bzero((char*) warn_count, sizeof(warn_count));
  total_warn_count= 0;
299
  update_charset();
unknown's avatar
unknown committed
300 301
}

302

303 304 305 306 307 308 309 310
/*
  Init THD for query processing.
  This has to be called once before we call mysql_parse.
  See also comments in sql_class.h.
*/

void THD::init_for_queries()
{
311
  ha_enable_transaction(this,TRUE);
312

unknown's avatar
unknown committed
313
  reset_root_defaults(mem_root, variables.query_alloc_block_size,
314 315 316 317
                      variables.query_prealloc_size);
  reset_root_defaults(&transaction.mem_root,
                      variables.trans_alloc_block_size,
                      variables.trans_prealloc_size);
318 319 320
}


unknown's avatar
unknown committed
321 322 323 324 325 326 327 328 329 330 331 332 333 334
/*
  Do what's needed when one invokes change user

  SYNOPSIS
    change_user()

  IMPLEMENTATION
    Reset all resources that are connection specific
*/


void THD::change_user(void)
{
  cleanup();
unknown's avatar
unknown committed
335
  cleanup_done= 0;
unknown's avatar
unknown committed
336
  init();
337
  stmt_map.reset();
unknown's avatar
unknown committed
338
  hash_init(&user_vars, &my_charset_bin, USER_VARS_HASH_SIZE, 0, 0,
unknown's avatar
unknown committed
339
	    (hash_get_key) get_var_key,
unknown's avatar
unknown committed
340
	    (hash_free_key) free_user_var, 0);
unknown's avatar
unknown committed
341 342 343
}


unknown's avatar
unknown committed
344 345 346
/* Do operations that may take a long time */

void THD::cleanup(void)
unknown's avatar
unknown committed
347
{
unknown's avatar
unknown committed
348
  DBUG_ENTER("THD::cleanup");
unknown's avatar
unknown committed
349 350 351 352 353 354
  ha_rollback(this);
  if (locked_tables)
  {
    lock=locked_tables; locked_tables=0;
    close_thread_tables(this);
  }
355
  mysql_ha_flush(this, (TABLE_LIST*) 0,
356
                 MYSQL_HA_CLOSE_FINAL | MYSQL_HA_FLUSH_ALL, FALSE);
357
  hash_free(&handler_tables_hash);
358 359
  delete_dynamic(&user_var_events);
  hash_free(&user_vars);
unknown's avatar
unknown committed
360
  close_temporary_tables(this);
361 362 363
  my_free((char*) variables.time_format, MYF(MY_ALLOW_ZERO_PTR));
  my_free((char*) variables.date_format, MYF(MY_ALLOW_ZERO_PTR));
  my_free((char*) variables.datetime_format, MYF(MY_ALLOW_ZERO_PTR));
unknown's avatar
unknown committed
364 365 366
  if (global_read_lock)
    unlock_global_read_lock(this);
  if (ull)
367
  {
unknown's avatar
unknown committed
368 369 370 371
    pthread_mutex_lock(&LOCK_user_locks);
    item_user_lock_release(ull);
    pthread_mutex_unlock(&LOCK_user_locks);
    ull= 0;
372
  }
unknown's avatar
unknown committed
373 374 375 376
  cleanup_done=1;
  DBUG_VOID_RETURN;
}

unknown's avatar
unknown committed
377

unknown's avatar
unknown committed
378 379
THD::~THD()
{
380
  THD_CHECK_SENTRY(this);
unknown's avatar
unknown committed
381
  DBUG_ENTER("~THD()");
382 383 384 385
  /* Ensure that no one is using THD */
  pthread_mutex_lock(&LOCK_delete);
  pthread_mutex_unlock(&LOCK_delete);

unknown's avatar
unknown committed
386
  /* Close connection */
387
#ifndef EMBEDDED_LIBRARY  
unknown's avatar
unknown committed
388 389 390 391 392
  if (net.vio)
  {
    vio_delete(net.vio);
    net_end(&net); 
  }
393
#endif
unknown's avatar
unknown committed
394 395
  if (!cleanup_done)
    cleanup();
unknown's avatar
unknown committed
396 397
#ifdef USING_TRANSACTIONS
  if (opt_using_transactions)
unknown's avatar
unknown committed
398
  {
unknown's avatar
unknown committed
399 400
    close_cached_file(&transaction.trans_log);
    ha_close_connection(this);
unknown's avatar
unknown committed
401
  }
unknown's avatar
unknown committed
402
#endif
unknown's avatar
unknown committed
403 404

  DBUG_PRINT("info", ("freeing host"));
unknown's avatar
unknown committed
405
  if (host != my_localhost)			// If not pointer to constant
406
    safeFree(host);
407 408
  if (user != delayed_user)
    safeFree(user);
unknown's avatar
unknown committed
409
  safeFree(ip);
410
  safeFree(db);
411
  free_root(&warn_root,MYF(0));
412
  free_root(&transaction.mem_root,MYF(0));
unknown's avatar
unknown committed
413
  mysys_var=0;					// Safety (shouldn't be needed)
414
  pthread_mutex_destroy(&LOCK_delete);
415 416
#ifndef DBUG_OFF
  dbug_sentry = THD_SENTRY_GONE;
417
#endif  
418
  /* Reset stmt_backup.mem_root to not double-free memory from thd.mem_root */
unknown's avatar
unknown committed
419
  clear_alloc_root(&stmt_backup.main_mem_root);
unknown's avatar
unknown committed
420 421 422
  DBUG_VOID_RETURN;
}

423

424
void THD::awake(bool prepare_to_die)
425
{
426
  THD_CHECK_SENTRY(this);
427 428
  safe_mutex_assert_owner(&LOCK_delete); 

429 430
  if (prepare_to_die)
    killed = 1;
431 432 433 434 435
  thr_alarm_kill(real_id);
#ifdef SIGNAL_WITH_VIO_CLOSE
  close_active_vio();
#endif    
  if (mysys_var)
unknown's avatar
unknown committed
436 437 438 439 440 441 442 443 444
  {
    pthread_mutex_lock(&mysys_var->mutex);
    if (!system_thread)		// Don't abort locks
      mysys_var->abort=1;
    /*
      This broadcast could be up in the air if the victim thread
      exits the cond in the time between read and broadcast, but that is
      ok since all we want to do is to make the victim thread get out
      of waiting on current_cond.
445 446 447 448 449
      If we see a non-zero current_cond: it cannot be an old value (because
      then exit_cond() should have run and it can't because we have mutex); so
      it is the true value but maybe current_mutex is not yet non-zero (we're
      in the middle of enter_cond() and there is a "memory order
      inversion"). So we test the mutex too to not lock 0.
450

451
      Note that there is a small chance we fail to kill. If victim has locked
452 453 454 455 456
      current_mutex, but hasn't yet entered enter_cond() (which means that
      current_cond and current_mutex are 0), then the victim will not get
      a signal and it may wait "forever" on the cond (until
      we issue a second KILL or the status it's waiting for happens).
      It's true that we have set its thd->killed but it may not
457
      see it immediately and so may have time to reach the cond_wait().
unknown's avatar
unknown committed
458
    */
459
    if (mysys_var->current_cond && mysys_var->current_mutex)
460
    {
unknown's avatar
unknown committed
461 462 463
      pthread_mutex_lock(mysys_var->current_mutex);
      pthread_cond_broadcast(mysys_var->current_cond);
      pthread_mutex_unlock(mysys_var->current_mutex);
464
    }
unknown's avatar
unknown committed
465 466
    pthread_mutex_unlock(&mysys_var->mutex);
  }
467 468
}

unknown's avatar
unknown committed
469 470 471 472
/*
  Remember the location of thread info, the structure needed for
  sql_alloc() and the structure for the net buffer
*/
unknown's avatar
unknown committed
473 474 475

bool THD::store_globals()
{
476
  if (my_pthread_setspecific_ptr(THR_THD,  this) ||
unknown's avatar
unknown committed
477
      my_pthread_setspecific_ptr(THR_MALLOC, &mem_root))
478 479 480
    return 1;
  mysys_var=my_thread_var;
  dbug_thread_id=my_thread_id();
unknown's avatar
unknown committed
481 482 483 484
  /*
    By default 'slave_proxy_id' is 'thread_id'. They may later become different
    if this is the slave SQL thread.
  */
485
  variables.pseudo_thread_id= thread_id;
486
  return 0;
unknown's avatar
unknown committed
487 488
}

unknown's avatar
unknown committed
489

unknown's avatar
unknown committed
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
/*
  Convert a string to another character set

  SYNOPSIS
    convert_string()
    to				Store new allocated string here
    to_cs			New character set for allocated string
    from			String to convert
    from_length			Length of string to convert
    from_cs			Original character set

  NOTES
    to will be 0-terminated to make it easy to pass to system funcs

  RETURN
    0	ok
    1	End of memory.
        In this case to->str will point to 0 and to->length will be 0.
*/

bool THD::convert_string(LEX_STRING *to, CHARSET_INFO *to_cs,
			 const char *from, uint from_length,
			 CHARSET_INFO *from_cs)
{
  DBUG_ENTER("convert_string");
  size_s new_length= to_cs->mbmaxlen * from_length;
516
  uint dummy_errors;
unknown's avatar
unknown committed
517 518 519 520 521 522
  if (!(to->str= alloc(new_length+1)))
  {
    to->length= 0;				// Safety fix
    DBUG_RETURN(1);				// EOM
  }
  to->length= copy_and_convert((char*) to->str, new_length, to_cs,
523
			       from, from_length, from_cs, &dummy_errors);
unknown's avatar
unknown committed
524 525 526 527 528
  to->str[to->length]=0;			// Safety
  DBUG_RETURN(0);
}


529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545
/*
  Convert string from source character set to target character set inplace.

  SYNOPSIS
    THD::convert_string

  DESCRIPTION
    Convert string using convert_buffer - buffer for character set 
    conversion shared between all protocols.

  RETURN
    0   ok
   !0   out of memory
*/

bool THD::convert_string(String *s, CHARSET_INFO *from_cs, CHARSET_INFO *to_cs)
{
546 547
  uint dummy_errors;
  if (convert_buffer.copy(s->ptr(), s->length(), from_cs, to_cs, &dummy_errors))
548 549 550 551 552 553 554 555 556 557 558
    return TRUE;
  /* If convert_buffer >> s copying is more efficient long term */
  if (convert_buffer.alloced_length() >= convert_buffer.length() * 2 ||
      !s->is_alloced())
  {
    return s->copy(convert_buffer);
  }
  s->swap(convert_buffer);
  return FALSE;
}

559

unknown's avatar
unknown committed
560 561 562 563 564 565
/*
  Update some cache variables when character set changes
*/

void THD::update_charset()
{
566 567 568 569 570 571 572
  uint32 not_used;
  charset_is_system_charset= !String::needs_conversion(0,charset(),
                                                       system_charset_info,
                                                       &not_used);
  charset_is_collation_connection= 
    !String::needs_conversion(0,charset(),variables.collation_connection,
                              &not_used);
unknown's avatar
unknown committed
573 574 575
}


576 577 578 579 580 581 582 583 584 585 586 587 588 589
/* routings to adding tables to list of changed in transaction tables */

inline static void list_include(CHANGED_TABLE_LIST** prev,
				CHANGED_TABLE_LIST* curr,
				CHANGED_TABLE_LIST* new_table)
{
  if (new_table)
  {
    *prev = new_table;
    (*prev)->next = curr;
  }
}

/* add table to list of changed in transaction tables */
590

591 592
void THD::add_changed_table(TABLE *table)
{
593
  DBUG_ENTER("THD::add_changed_table(table)");
594

unknown's avatar
unknown committed
595
  DBUG_ASSERT((options & (OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN)) &&
596
	      table->file->has_transactions());
unknown's avatar
unknown committed
597 598
  add_changed_table(table->table_cache_key, table->key_length);
  DBUG_VOID_RETURN;
unknown's avatar
unknown committed
599
}
600

601

unknown's avatar
unknown committed
602 603 604
void THD::add_changed_table(const char *key, long key_length)
{
  DBUG_ENTER("THD::add_changed_table(key)");
605 606
  CHANGED_TABLE_LIST **prev_changed = &transaction.changed_tables;
  CHANGED_TABLE_LIST *curr = transaction.changed_tables;
607

608
  for (; curr; prev_changed = &(curr->next), curr = curr->next)
609
  {
unknown's avatar
unknown committed
610
    int cmp =  (long)curr->key_length - (long)key_length;
611 612
    if (cmp < 0)
    {
613
      list_include(prev_changed, curr, changed_table_dup(key, key_length));
614
      DBUG_PRINT("info", 
615
		 ("key_length %u %u", key_length, (*prev_changed)->key_length));
616 617 618 619
      DBUG_VOID_RETURN;
    }
    else if (cmp == 0)
    {
unknown's avatar
unknown committed
620
      cmp = memcmp(curr->key, key, curr->key_length);
621 622
      if (cmp < 0)
      {
623
	list_include(prev_changed, curr, changed_table_dup(key, key_length));
624
	DBUG_PRINT("info", 
unknown's avatar
unknown committed
625
		   ("key_length %u %u", key_length,
626
		    (*prev_changed)->key_length));
627 628 629 630 631 632 633 634 635
	DBUG_VOID_RETURN;
      }
      else if (cmp == 0)
      {
	DBUG_PRINT("info", ("already in list"));
	DBUG_VOID_RETURN;
      }
    }
  }
636
  *prev_changed = changed_table_dup(key, key_length);
unknown's avatar
unknown committed
637
  DBUG_PRINT("info", ("key_length %u %u", key_length,
638
		      (*prev_changed)->key_length));
639 640 641
  DBUG_VOID_RETURN;
}

642

unknown's avatar
unknown committed
643
CHANGED_TABLE_LIST* THD::changed_table_dup(const char *key, long key_length)
644 645 646
{
  CHANGED_TABLE_LIST* new_table = 
    (CHANGED_TABLE_LIST*) trans_alloc(ALIGN_SIZE(sizeof(CHANGED_TABLE_LIST))+
unknown's avatar
unknown committed
647
				      key_length + 1);
648 649 650
  if (!new_table)
  {
    my_error(EE_OUTOFMEMORY, MYF(ME_BELL),
unknown's avatar
unknown committed
651
	     ALIGN_SIZE(sizeof(TABLE_LIST)) + key_length + 1);
652 653 654 655 656 657 658
    killed= 1;
    return 0;
  }

  new_table->key = (char *) (((byte*)new_table)+
			     ALIGN_SIZE(sizeof(CHANGED_TABLE_LIST)));
  new_table->next = 0;
unknown's avatar
unknown committed
659 660
  new_table->key_length = key_length;
  ::memcpy(new_table->key, key, key_length);
661 662 663
  return new_table;
}

664

unknown's avatar
unknown committed
665 666 667 668
int THD::send_explain_fields(select_result *result)
{
  List<Item> field_list;
  Item *item;
669
  CHARSET_INFO *cs= system_charset_info;
670
  field_list.push_back(new Item_return_int("id",3, MYSQL_TYPE_LONGLONG));
671
  field_list.push_back(new Item_empty_string("select_type", 19, cs));
unknown's avatar
unknown committed
672 673 674 675
  field_list.push_back(item= new Item_empty_string("table", NAME_LEN, cs));
  item->maybe_null= 1;
  field_list.push_back(item= new Item_empty_string("type", 10, cs));
  item->maybe_null= 1;
unknown's avatar
unknown committed
676
  field_list.push_back(item=new Item_empty_string("possible_keys",
677
						  NAME_LEN*MAX_KEY, cs));
unknown's avatar
unknown committed
678
  item->maybe_null=1;
679
  field_list.push_back(item=new Item_empty_string("key", NAME_LEN, cs));
unknown's avatar
unknown committed
680
  item->maybe_null=1;
681 682
  field_list.push_back(item=new Item_return_int("key_len",3,
						MYSQL_TYPE_LONGLONG));
unknown's avatar
unknown committed
683 684
  item->maybe_null=1;
  field_list.push_back(item=new Item_empty_string("ref",
685
						  NAME_LEN*MAX_REF_PARTS, cs));
unknown's avatar
unknown committed
686
  item->maybe_null=1;
unknown's avatar
unknown committed
687 688 689
  field_list.push_back(item= new Item_return_int("rows", 10,
                                                 MYSQL_TYPE_LONGLONG));
  item->maybe_null= 1;
690
  field_list.push_back(new Item_empty_string("Extra", 255, cs));
unknown's avatar
unknown committed
691 692
  return (result->send_fields(field_list,1));
}
693

unknown's avatar
unknown committed
694 695 696
#ifdef SIGNAL_WITH_VIO_CLOSE
void THD::close_active_vio()
{
unknown's avatar
unknown committed
697
  DBUG_ENTER("close_active_vio");
unknown's avatar
unknown committed
698
  safe_mutex_assert_owner(&LOCK_delete); 
unknown's avatar
unknown committed
699
#ifndef EMBEDDED_LIBRARY
unknown's avatar
unknown committed
700 701 702 703 704
  if (active_vio)
  {
    vio_close(active_vio);
    active_vio = 0;
  }
unknown's avatar
unknown committed
705
#endif
706
  DBUG_VOID_RETURN;
unknown's avatar
unknown committed
707 708 709
}
#endif

710

711 712 713 714 715
struct Item_change_record: public ilink
{
  Item **place;
  Item *old_value;
  /* Placement new was hidden by `new' in ilink (TODO: check): */
716
  static void *operator new(size_t size, void *mem) { return mem; }
717 718
  static void operator delete(void *ptr, size_t size) {}
  static void operator delete(void *ptr, void *mem) { /* never called */ }
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
};


/*
  Register an item tree tree transformation, performed by the query
  optimizer. We need a pointer to runtime_memroot because it may be !=
  thd->mem_root (due to possible set_n_backup_item_arena called for thd).
*/

void THD::nocheck_register_item_tree_change(Item **place, Item *old_value,
                                            MEM_ROOT *runtime_memroot)
{
  Item_change_record *change;
  /*
    Now we use one node per change, which adds some memory overhead,
    but still is rather fast as we use alloc_root for allocations.
    A list of item tree changes of an average query should be short.
  */
  void *change_mem= alloc_root(runtime_memroot, sizeof(*change));
  if (change_mem == 0)
  {
    fatal_error();
    return;
  }
  change= new (change_mem) Item_change_record;
  change->place= place;
  change->old_value= old_value;
746
  change_list.append(change);
747 748 749 750 751 752 753 754 755 756 757 758 759 760
}


void THD::rollback_item_tree_changes()
{
  I_List_iterator<Item_change_record> it(change_list);
  Item_change_record *change;
  while ((change= it++))
    *change->place= change->old_value;
  /* We can forget about changes memory: it's allocated in runtime memroot */
  change_list.empty();
}


unknown's avatar
unknown committed
761 762 763 764 765 766 767 768 769
/*****************************************************************************
** Functions to provide a interface to select results
*****************************************************************************/

select_result::select_result()
{
  thd=current_thd;
}

770 771 772 773 774
void select_result::send_error(uint errcode,const char *err)
{
  ::send_error(thd, errcode, err);
}

775 776 777 778 779 780

void select_result::cleanup()
{
  /* do nothing */
}

781 782 783
static String default_line_term("\n",default_charset_info);
static String default_escaped("\\",default_charset_info);
static String default_field_term("\t",default_charset_info);
unknown's avatar
unknown committed
784 785 786 787 788

sql_exchange::sql_exchange(char *name,bool flag)
  :file_name(name), opt_enclosed(0), dumpfile(flag), skip_lines(0)
{
  field_term= &default_field_term;
unknown's avatar
SCRUM  
unknown committed
789
  enclosed=   line_start= &my_empty_string;
unknown's avatar
unknown committed
790 791 792 793 794 795
  line_term=  &default_line_term;
  escaped=    &default_escaped;
}

bool select_send::send_fields(List<Item> &list,uint flag)
{
796
  return thd->protocol->send_fields(&list,flag);
unknown's avatar
unknown committed
797 798 799 800 801 802
}

/* Send data to client. Returns 0 if ok */

bool select_send::send_data(List<Item> &items)
{
803
  if (unit->offset_limit_cnt)
unknown's avatar
unknown committed
804
  {						// using limit offset,count
805
    unit->offset_limit_cnt--;
806
    return 0;
unknown's avatar
unknown committed
807
  }
808

809
#ifdef HAVE_INNOBASE_DB
unknown's avatar
unknown committed
810 811 812 813 814
  /*
    We may be passing the control from mysqld to the client: release the
    InnoDB adaptive hash S-latch to avoid thread deadlocks if it was reserved
    by thd
  */
815 816 817 818
  if (thd->transaction.all.innobase_tid)
    ha_release_temporary_latches(thd);
#endif

819 820 821
  List_iterator_fast<Item> li(items);
  Protocol *protocol= thd->protocol;
  char buff[MAX_FIELD_WIDTH];
unknown's avatar
unknown committed
822
  String buffer(buff, sizeof(buff), &my_charset_bin);
823 824 825
  DBUG_ENTER("send_data");

  protocol->prepare_for_resend();
unknown's avatar
unknown committed
826 827 828
  Item *item;
  while ((item=li++))
  {
829
    if (item->send(protocol, &buffer))
unknown's avatar
unknown committed
830
    {
831
      protocol->free();				// Free used buffer
unknown's avatar
unknown committed
832
      my_message(ER_OUT_OF_RESOURCES, ER(ER_OUT_OF_RESOURCES), MYF(0));
833
      break;
unknown's avatar
unknown committed
834 835
    }
  }
836
  thd->sent_row_count++;
837
  if (!thd->vio_ok())
838
    DBUG_RETURN(0);
unknown's avatar
unknown committed
839
  if (!thd->net.report_error)
840 841
    DBUG_RETURN(protocol->write());
  DBUG_RETURN(1);
unknown's avatar
unknown committed
842 843 844 845
}

bool select_send::send_eof()
{
846 847 848 849 850 851 852 853
#ifdef HAVE_INNOBASE_DB
  /* We may be passing the control from mysqld to the client: release the
     InnoDB adaptive hash S-latch to avoid thread deadlocks if it was reserved
     by thd */
  if (thd->transaction.all.innobase_tid)
    ha_release_temporary_latches(thd);
#endif

unknown's avatar
unknown committed
854 855 856
  /* Unlock tables before sending packet to gain some speed */
  if (thd->lock)
  {
857 858
    mysql_unlock_tables(thd, thd->lock);
    thd->lock=0;
unknown's avatar
unknown committed
859
  }
unknown's avatar
unknown committed
860 861
  if (!thd->net.report_error)
  {
unknown's avatar
unknown committed
862
    ::send_eof(thd);
unknown's avatar
unknown committed
863 864 865 866
    return 0;
  }
  else
    return 1;
unknown's avatar
unknown committed
867 868 869
}


870 871 872
/************************************************************************
  Handling writing to file
************************************************************************/
unknown's avatar
unknown committed
873

874 875 876 877 878 879 880 881 882 883 884
void select_to_file::send_error(uint errcode,const char *err)
{
  ::send_error(thd,errcode,err);
  if (file > 0)
  {
    (void) end_io_cache(&cache);
    (void) my_close(file,MYF(0));
    (void) my_delete(path,MYF(0));		// Delete file on error
    file= -1;
  }
}
unknown's avatar
unknown committed
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
bool select_to_file::send_eof()
{
  int error= test(end_io_cache(&cache));
  if (my_close(file,MYF(MY_WME)))
    error= 1;
  if (!error)
    ::send_ok(thd,row_count);
  file= -1;
  return error;
}


void select_to_file::cleanup()
{
  /* In case of error send_eof() may be not called: close the file here. */
  if (file >= 0)
  {
    (void) end_io_cache(&cache);
    (void) my_close(file,MYF(0));
    file= -1;
  }
  path[0]= '\0';
  row_count= 0;
}


913
select_to_file::~select_to_file()
unknown's avatar
unknown committed
914 915 916 917 918 919 920
{
  if (file >= 0)
  {					// This only happens in case of error
    (void) end_io_cache(&cache);
    (void) my_close(file,MYF(0));
    file= -1;
  }
921 922 923 924 925 926 927 928
}

/***************************************************************************
** Export of select to textfile
***************************************************************************/

select_export::~select_export()
{
929
  thd->sent_row_count=row_count;
unknown's avatar
unknown committed
930 931
}

932

933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950
/*
  Create file with IO cache

  SYNOPSIS
    create_file()
    thd			Thread handle
    path		File name
    exchange		Excange class
    cache		IO cache

  RETURN
    >= 0 	File handle
   -1		Error
*/


static File create_file(THD *thd, char *path, sql_exchange *exchange,
			IO_CACHE *cache)
unknown's avatar
unknown committed
951
{
952 953
  File file;
  uint option= MY_UNPACK_FILENAME;
954

unknown's avatar
unknown committed
955
#ifdef DONT_ALLOW_FULL_LOAD_DATA_PATHS
956
  option|= MY_REPLACE_DIR;			// Force use of db directory
unknown's avatar
unknown committed
957
#endif
958

unknown's avatar
unknown committed
959
  if (!dirname_length(exchange->file_name))
960 961 962 963 964 965 966
  {
    strxnmov(path, FN_REFLEN, mysql_real_data_home, thd->db ? thd->db : "", NullS);
    (void) fn_format(path, exchange->file_name, path, "", option);
  }
  else
    (void) fn_format(path, exchange->file_name, mysql_real_data_home, "", option);
    
967
  if (!access(path, F_OK))
unknown's avatar
unknown committed
968
  {
unknown's avatar
unknown committed
969
    my_error(ER_FILE_EXISTS_ERROR, MYF(0), exchange->file_name);
unknown's avatar
unknown committed
970
    return -1;
unknown's avatar
unknown committed
971 972
  }
  /* Create the file world readable */
unknown's avatar
unknown committed
973
  if ((file= my_create(path, 0666, O_WRONLY|O_EXCL, MYF(MY_WME))) < 0)
974
    return file;
unknown's avatar
unknown committed
975
#ifdef HAVE_FCHMOD
976
  (void) fchmod(file, 0666);			// Because of umask()
unknown's avatar
unknown committed
977
#else
978
  (void) chmod(path, 0666);
unknown's avatar
unknown committed
979
#endif
980
  if (init_io_cache(cache, file, 0L, WRITE_CACHE, 0L, 1, MYF(MY_WME)))
unknown's avatar
unknown committed
981
  {
982
    my_close(file, MYF(0));
983
    my_delete(path, MYF(0));  // Delete file on error, it was just created 
984
    return -1;
unknown's avatar
unknown committed
985
  }
986
  return file;
987 988 989 990 991 992 993 994 995 996 997
}


int
select_export::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
{
  bool blob_flag=0;
  unit= u;
  if ((uint) strlen(exchange->file_name) + NAME_LEN >= FN_REFLEN)
    strmake(path,exchange->file_name,FN_REFLEN-1);

998
  if ((file= create_file(thd, path, exchange, &cache)) < 0)
999
    return 1;
unknown's avatar
unknown committed
1000 1001
  /* Check if there is any blobs in data */
  {
unknown's avatar
unknown committed
1002
    List_iterator_fast<Item> li(list);
unknown's avatar
unknown committed
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
    Item *item;
    while ((item=li++))
    {
      if (item->max_length >= MAX_BLOB_WIDTH)
      {
	blob_flag=1;
	break;
      }
    }
  }
  field_term_length=exchange->field_term->length();
  if (!exchange->line_term->length())
    exchange->line_term=exchange->field_term;	// Use this if it exists
  field_sep_char= (exchange->enclosed->length() ? (*exchange->enclosed)[0] :
		   field_term_length ? (*exchange->field_term)[0] : INT_MAX);
  escape_char=	(exchange->escaped->length() ? (*exchange->escaped)[0] : -1);
  line_sep_char= (exchange->line_term->length() ?
		  (*exchange->line_term)[0] : INT_MAX);
  if (!field_term_length)
    exchange->opt_enclosed=0;
  if (!exchange->enclosed->length())
    exchange->opt_enclosed=1;			// A little quicker loop
  fixed_row_size= (!field_term_length && !exchange->enclosed->length() &&
		   !blob_flag);
  return 0;
}


bool select_export::send_data(List<Item> &items)
{

  DBUG_ENTER("send_data");
  char buff[MAX_FIELD_WIDTH],null_buff[2],space[MAX_FIELD_WIDTH];
  bool space_inited=0;
unknown's avatar
unknown committed
1037
  String tmp(buff,sizeof(buff),&my_charset_bin),*res;
unknown's avatar
unknown committed
1038 1039
  tmp.length(0);

1040
  if (unit->offset_limit_cnt)
unknown's avatar
unknown committed
1041
  {						// using limit offset,count
1042
    unit->offset_limit_cnt--;
unknown's avatar
unknown committed
1043 1044 1045 1046 1047 1048
    DBUG_RETURN(0);
  }
  row_count++;
  Item *item;
  char *buff_ptr=buff;
  uint used_length=0,items_left=items.elements;
unknown's avatar
unknown committed
1049
  List_iterator_fast<Item> li(items);
unknown's avatar
unknown committed
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

  if (my_b_write(&cache,(byte*) exchange->line_start->ptr(),
		 exchange->line_start->length()))
    goto err;
  while ((item=li++))
  {
    Item_result result_type=item->result_type();
    res=item->str_result(&tmp);
    if (res && (!exchange->opt_enclosed || result_type == STRING_RESULT))
    {
      if (my_b_write(&cache,(byte*) exchange->enclosed->ptr(),
		     exchange->enclosed->length()))
	goto err;
    }
    if (!res)
    {						// NULL
      if (!fixed_row_size)
      {
	if (escape_char != -1)			// Use \N syntax
	{
	  null_buff[0]=escape_char;
	  null_buff[1]='N';
	  if (my_b_write(&cache,(byte*) null_buff,2))
	    goto err;
	}
	else if (my_b_write(&cache,(byte*) "NULL",4))
	  goto err;
      }
      else
      {
	used_length=0;				// Fill with space
      }
    }
    else
    {
      if (fixed_row_size)
	used_length=min(res->length(),item->max_length);
      else
	used_length=res->length();
      if (result_type == STRING_RESULT && escape_char != -1)
      {
	char *pos,*start,*end;

	for (start=pos=(char*) res->ptr(),end=pos+used_length ;
	     pos != end ;
	     pos++)
	{
#ifdef USE_MB
unknown's avatar
unknown committed
1098 1099
          CHARSET_INFO *res_charset=res->charset();
	  if (use_mb(res_charset))
unknown's avatar
unknown committed
1100 1101
	  {
	    int l;
unknown's avatar
unknown committed
1102
	    if ((l=my_ismbchar(res_charset, pos, end)))
unknown's avatar
unknown committed
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
	    {
	      pos += l-1;
	      continue;
	    }
	  }
#endif
	  if ((int) *pos == escape_char || (int) *pos == field_sep_char ||
	      (int) *pos == line_sep_char || !*pos)
	  {
	    char tmp_buff[2];
	    tmp_buff[0]= escape_char;
	    tmp_buff[1]= *pos ? *pos : '0';
	    if (my_b_write(&cache,(byte*) start,(uint) (pos-start)) ||
		my_b_write(&cache,(byte*) tmp_buff,2))
	      goto err;
	    start=pos+1;
	  }
	}
	if (my_b_write(&cache,(byte*) start,(uint) (pos-start)))
	  goto err;
      }
      else if (my_b_write(&cache,(byte*) res->ptr(),used_length))
	goto err;
    }
    if (fixed_row_size)
    {						// Fill with space
      if (item->max_length > used_length)
      {
	/* QQ:  Fix by adding a my_b_fill() function */
	if (!space_inited)
	{
	  space_inited=1;
	  bfill(space,sizeof(space),' ');
	}
	uint length=item->max_length-used_length;
1138
	for (; length > sizeof(space) ; length-=sizeof(space))
unknown's avatar
unknown committed
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
	{
	  if (my_b_write(&cache,(byte*) space,sizeof(space)))
	    goto err;
	}
	if (my_b_write(&cache,(byte*) space,length))
	  goto err;
      }
    }
    buff_ptr=buff;				// Place separators here
    if (res && (!exchange->opt_enclosed || result_type == STRING_RESULT))
    {
      memcpy(buff_ptr,exchange->enclosed->ptr(),exchange->enclosed->length());
      buff_ptr+=exchange->enclosed->length();
    }
    if (--items_left)
    {
      memcpy(buff_ptr,exchange->field_term->ptr(),field_term_length);
      buff_ptr+=field_term_length;
    }
    if (my_b_write(&cache,(byte*) buff,(uint) (buff_ptr-buff)))
      goto err;
  }
  if (my_b_write(&cache,(byte*) exchange->line_term->ptr(),
		 exchange->line_term->length()))
    goto err;
  DBUG_RETURN(0);
err:
  DBUG_RETURN(1);
}


/***************************************************************************
** Dump  of select to a binary file
***************************************************************************/


int
1176 1177
select_dump::prepare(List<Item> &list __attribute__((unused)),
		     SELECT_LEX_UNIT *u)
unknown's avatar
unknown committed
1178
{
1179
  unit= u;
1180
  return (int) ((file= create_file(thd, path, exchange, &cache)) < 0);
unknown's avatar
unknown committed
1181 1182 1183 1184 1185
}


bool select_dump::send_data(List<Item> &items)
{
unknown's avatar
unknown committed
1186
  List_iterator_fast<Item> li(items);
unknown's avatar
unknown committed
1187
  char buff[MAX_FIELD_WIDTH];
unknown's avatar
unknown committed
1188
  String tmp(buff,sizeof(buff),&my_charset_bin),*res;
unknown's avatar
unknown committed
1189 1190 1191 1192
  tmp.length(0);
  Item *item;
  DBUG_ENTER("send_data");

1193
  if (unit->offset_limit_cnt)
unknown's avatar
unknown committed
1194
  {						// using limit offset,count
1195
    unit->offset_limit_cnt--;
unknown's avatar
unknown committed
1196 1197 1198 1199
    DBUG_RETURN(0);
  }
  if (row_count++ > 1) 
  {
unknown's avatar
unknown committed
1200
    my_error(ER_TOO_MANY_ROWS, MYF(0));
unknown's avatar
unknown committed
1201 1202 1203 1204 1205
    goto err;
  }
  while ((item=li++))
  {
    res=item->str_result(&tmp);
1206
    if (!res)					// If NULL
unknown's avatar
unknown committed
1207
    {
1208 1209
      if (my_b_write(&cache,(byte*) "",1))
	goto err;
unknown's avatar
unknown committed
1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222
    }
    else if (my_b_write(&cache,(byte*) res->ptr(),res->length()))
    {
      my_error(ER_ERROR_ON_WRITE,MYF(0), path, my_errno);
      goto err;
    }
  }
  DBUG_RETURN(0);
err:
  DBUG_RETURN(1);
}


1223
select_subselect::select_subselect(Item_subselect *item_arg)
1224
{
1225
  item= item_arg;
1226 1227
}

1228

unknown's avatar
unknown committed
1229
bool select_singlerow_subselect::send_data(List<Item> &items)
1230
{
unknown's avatar
unknown committed
1231 1232
  DBUG_ENTER("select_singlerow_subselect::send_data");
  Item_singlerow_subselect *it= (Item_singlerow_subselect *)item;
unknown's avatar
unknown committed
1233 1234
  if (it->assigned())
  {
1235
    my_message(ER_SUBQUERY_NO_1_ROW, ER(ER_SUBQUERY_NO_1_ROW), MYF(0));
unknown's avatar
unknown committed
1236 1237 1238
    DBUG_RETURN(1);
  }
  if (unit->offset_limit_cnt)
unknown's avatar
unknown committed
1239
  {				          // Using limit offset,count
unknown's avatar
unknown committed
1240 1241
    unit->offset_limit_cnt--;
    DBUG_RETURN(0);
1242
  }
unknown's avatar
unknown committed
1243
  List_iterator_fast<Item> li(items);
1244 1245 1246
  Item *val_item;
  for (uint i= 0; (val_item= li++); i++)
    it->store(i, val_item);
unknown's avatar
unknown committed
1247
  it->assigned(1);
unknown's avatar
unknown committed
1248
  DBUG_RETURN(0);
1249
}
unknown's avatar
unknown committed
1250

1251

1252 1253 1254 1255 1256 1257 1258 1259
void select_max_min_finder_subselect::cleanup()
{
  DBUG_ENTER("select_max_min_finder_subselect::cleanup");
  cache= 0;
  DBUG_VOID_RETURN;
}


1260 1261 1262
bool select_max_min_finder_subselect::send_data(List<Item> &items)
{
  DBUG_ENTER("select_max_min_finder_subselect::send_data");
1263
  Item_maxmin_subselect *it= (Item_maxmin_subselect *)item;
1264 1265
  List_iterator_fast<Item> li(items);
  Item *val_item= li++;
1266
  it->register_value();
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
  if (it->assigned())
  {
    cache->store(val_item);
    if ((this->*op)())
      it->store(0, cache);
  }
  else
  {
    if (!cache)
    {
      cache= Item_cache::get_cache(val_item->result_type());
      switch (val_item->result_type())
      {
      case REAL_RESULT:
	op= &select_max_min_finder_subselect::cmp_real;
	break;
      case INT_RESULT:
	op= &select_max_min_finder_subselect::cmp_int;
	break;
      case STRING_RESULT:
	op= &select_max_min_finder_subselect::cmp_str;
	break;
      case ROW_RESULT:
        // This case should never be choosen
	DBUG_ASSERT(0);
	op= 0;
      }
    }
    cache->store(val_item);
    it->store(0, cache);
  }
  it->assigned(1);
  DBUG_RETURN(0);
}

bool select_max_min_finder_subselect::cmp_real()
{
  Item *maxmin= ((Item_singlerow_subselect *)item)->el(0);
  double val1= cache->val(), val2= maxmin->val();
  if (fmax)
    return (cache->null_value && !maxmin->null_value) ||
      (!cache->null_value && !maxmin->null_value &&
       val1 > val2);
  else
    return (maxmin->null_value && !cache->null_value) ||
      (!cache->null_value && !maxmin->null_value &&
       val1 < val2);
}

bool select_max_min_finder_subselect::cmp_int()
{
  Item *maxmin= ((Item_singlerow_subselect *)item)->el(0);
  longlong val1= cache->val_int(), val2= maxmin->val_int();
  if (fmax)
    return (cache->null_value && !maxmin->null_value) ||
      (!cache->null_value && !maxmin->null_value &&
       val1 > val2);
  else
    return (maxmin->null_value && !cache->null_value) ||
      (!cache->null_value && !maxmin->null_value &&
       val1 < val2);
}

bool select_max_min_finder_subselect::cmp_str()
{
  String *val1, *val2, buf1, buf2;
  Item *maxmin= ((Item_singlerow_subselect *)item)->el(0);
  /*
    as far as both operand is Item_cache buf1 & buf2 will not be used,
    but added for safety
  */
  val1= cache->val_str(&buf1);
  val2= maxmin->val_str(&buf1);
  if (fmax)
    return (cache->null_value && !maxmin->null_value) ||
      (!cache->null_value && !maxmin->null_value &&
       sortcmp(val1, val2, cache->collation.collation) > 0) ;
  else
    return (maxmin->null_value && !cache->null_value) ||
      (!cache->null_value && !maxmin->null_value &&
       sortcmp(val1, val2, cache->collation.collation) < 0);
}

unknown's avatar
unknown committed
1350 1351 1352 1353 1354 1355 1356 1357 1358 1359
bool select_exists_subselect::send_data(List<Item> &items)
{
  DBUG_ENTER("select_exists_subselect::send_data");
  Item_exists_subselect *it= (Item_exists_subselect *)item;
  if (unit->offset_limit_cnt)
  {				          // Using limit offset,count
    unit->offset_limit_cnt--;
    DBUG_RETURN(0);
  }
  it->value= 1;
unknown's avatar
unknown committed
1360
  it->assigned(1);
unknown's avatar
unknown committed
1361 1362 1363
  DBUG_RETURN(0);
}

unknown's avatar
unknown committed
1364 1365

/***************************************************************************
1366
  Dump of select to variables
unknown's avatar
unknown committed
1367
***************************************************************************/
1368

1369
int select_dumpvar::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
unknown's avatar
unknown committed
1370
{
1371 1372
  List_iterator_fast<Item> li(list);
  List_iterator_fast<LEX_STRING> gl(var_list);
unknown's avatar
unknown committed
1373 1374
  Item *item;
  LEX_STRING *ls;
1375
  if (var_list.elements != list.elements)
unknown's avatar
unknown committed
1376
  {
1377 1378
    my_error(ER_WRONG_NUMBER_OF_COLUMNS_IN_SELECT, MYF(0));
    return 1;
unknown's avatar
unknown committed
1379
  }
1380
  unit=u;
1381
  while ((item=li++))
unknown's avatar
unknown committed
1382
  {
1383
    ls= gl++;
unknown's avatar
unknown committed
1384
    Item_func_set_user_var *xx = new Item_func_set_user_var(*ls,item);
1385 1386 1387 1388
    /*
      Item_func_set_user_var can't substitute something else on its place =>
      0 can be passed as last argument (reference on item)
    */
1389
    xx->fix_fields(thd,(TABLE_LIST*) thd->lex->select_lex.table_list.first,
1390
		   0);
unknown's avatar
unknown committed
1391
    xx->fix_length_and_dec();
1392
    vars.push_back(xx);
unknown's avatar
unknown committed
1393
  }
1394 1395
  return 0;
}
1396 1397


1398 1399 1400 1401 1402 1403 1404
void select_dumpvar::cleanup()
{
  vars.empty();
  row_count=0;
}


1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415
/*
  Create arena for already constructed THD.

  SYNOPSYS
    Item_arena()
      thd - thread for which arena is created

  DESCRIPTION
    Create arena for already existing THD using its variables as parameters
    for memory root initialization.
*/
1416
Item_arena::Item_arena(THD* thd)
unknown's avatar
unknown committed
1417 1418
  :free_list(0), mem_root(&main_mem_root),
   state(INITIALIZED)
1419
{
unknown's avatar
unknown committed
1420
  init_sql_alloc(&main_mem_root,
1421 1422 1423 1424 1425
                 thd->variables.query_alloc_block_size,
                 thd->variables.query_prealloc_size);
}


1426 1427
/*
  Create arena and optionally initialize memory root.
1428

1429 1430 1431
  SYNOPSYS
    Item_arena()
      init_mem_root - whenever we need to initialize memory root
1432

1433 1434 1435
  DESCRIPTION
    Create arena and optionally initialize memory root with minimal
    possible parameters.
1436

1437 1438 1439 1440 1441
  NOTE
    We use this constructor when arena is part of THD, but reinitialize
    its memory root in THD::init_for_queries() before execution of real
    statements.
*/
1442
Item_arena::Item_arena(bool init_mem_root)
unknown's avatar
unknown committed
1443
  :free_list(0), mem_root(&main_mem_root),
1444
  state(CONVENTIONAL_EXECUTION)
1445 1446
{
  if (init_mem_root)
unknown's avatar
unknown committed
1447
    init_sql_alloc(&main_mem_root, ALLOC_ROOT_MIN_BLOCK_SIZE, 0);
1448 1449
}

1450

1451 1452 1453 1454 1455 1456 1457
Item_arena::Type Item_arena::type() const
{
  DBUG_ASSERT("Item_arena::type()" == "abstract");
  return STATEMENT;
}


1458 1459 1460 1461 1462
/*
  Statement functions 
*/

Statement::Statement(THD *thd)
1463 1464
  :Item_arena(thd),
  id(++thd->statement_id_counter),
1465 1466 1467 1468
  set_query_id(1),
  allow_sum_func(0),
  lex(&main_lex),
  query(0),
1469
  query_length(0)
1470
{
1471
  name.str= NULL;
1472 1473 1474 1475 1476 1477 1478 1479 1480
}

/*
  This constructor is called when statement is a subobject of THD:
  Some variables are initialized in THD::init due to locking problems
  This statement object will be used to 
*/

Statement::Statement()
1481 1482
  :Item_arena((bool)TRUE),
  id(0),
1483 1484 1485 1486
  set_query_id(1),
  allow_sum_func(0),                            /* initialized later */
  lex(&main_lex),
  query(0),                                     /* these two are set */ 
1487
  query_length(0)                               /* in alloc_query() */
1488 1489 1490 1491
{
}


1492
Item_arena::Type Statement::type() const
1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508
{
  return STATEMENT;
}


void Statement::set_statement(Statement *stmt)
{
  id=             stmt->id;
  set_query_id=   stmt->set_query_id;
  allow_sum_func= stmt->allow_sum_func;
  lex=            stmt->lex;
  query=          stmt->query;
  query_length=   stmt->query_length;
}


1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523
void
Statement::set_n_backup_statement(Statement *stmt, Statement *backup)
{
  backup->set_statement(this);
  set_statement(stmt);
}


void Statement::restore_backup_statement(Statement *stmt, Statement *backup)
{
  stmt->set_statement(this);
  set_statement(backup);
}


1524
void THD::end_statement()
1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538
{
  /* Cleanup SQL processing state to resuse this statement in next query. */
  lex_end(lex);
  delete lex->result;
  lex->result= 0;
  free_items(free_list);
  free_list= 0;
  /*
    Don't free mem_root, as mem_root is freed in the end of dispatch_command
    (once for any command).
  */
}


1539
void Item_arena::set_n_backup_item_arena(Item_arena *set, Item_arena *backup)
unknown's avatar
unknown committed
1540
{
unknown's avatar
unknown committed
1541
  DBUG_ENTER("Item_arena::set_n_backup_item_arena");
1542
  backup->set_item_arena(this);
unknown's avatar
unknown committed
1543
  set_item_arena(set);
unknown's avatar
unknown committed
1544
  DBUG_VOID_RETURN;
unknown's avatar
unknown committed
1545 1546 1547
}


1548
void Item_arena::restore_backup_item_arena(Item_arena *set, Item_arena *backup)
1549
{
unknown's avatar
unknown committed
1550
  DBUG_ENTER("Item_arena::restore_backup_item_arena");
1551 1552
  set->set_item_arena(this);
  set_item_arena(backup);
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562
#ifdef NOT_NEEDED_NOW
  /*
    Reset backup mem_root to avoid its freeing.
    Since Item_arena's mem_root is freed only when it is part of Statement
    we need this only if we use some Statement's arena as backup storage.
    But we do this only with THD::stmt_backup and this Statement is specially
    handled in this respect. So this code is not really needed now.
  */
  clear_alloc_root(&backup->mem_root);
#endif
unknown's avatar
unknown committed
1563
  DBUG_VOID_RETURN;
1564 1565
}

1566
void Item_arena::set_item_arena(Item_arena *set)
unknown's avatar
unknown committed
1567
{
unknown's avatar
unknown committed
1568
  mem_root=  set->mem_root;
unknown's avatar
unknown committed
1569
  free_list= set->free_list;
1570
  state= set->state;
unknown's avatar
unknown committed
1571 1572
}

1573 1574
Statement::~Statement()
{
unknown's avatar
unknown committed
1575
  free_root(&main_mem_root, MYF(0));
1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593
}

C_MODE_START

static byte *
get_statement_id_as_hash_key(const byte *record, uint *key_length,
                             my_bool not_used __attribute__((unused)))
{
  const Statement *statement= (const Statement *) record; 
  *key_length= sizeof(statement->id);
  return (byte *) &((const Statement *) statement)->id;
}

static void delete_statement_as_hash_key(void *key)
{
  delete (Statement *) key;
}

1594 1595
static byte *get_stmt_name_hash_key(Statement *entry, uint *length,
                                    my_bool not_used __attribute__((unused)))
1596 1597 1598 1599 1600
{
  *length=(uint) entry->name.length;
  return (byte*) entry->name.str;
}

1601 1602 1603 1604 1605
C_MODE_END

Statement_map::Statement_map() :
  last_found_statement(0)
{
1606 1607 1608 1609 1610
  enum
  {
    START_STMT_HASH_SIZE = 16,
    START_NAME_HASH_SIZE = 16
  };
1611
  hash_init(&st_hash, &my_charset_bin, START_STMT_HASH_SIZE, 0, 0,
1612 1613
            get_statement_id_as_hash_key,
            delete_statement_as_hash_key, MYF(0));
1614
  hash_init(&names_hash, system_charset_info, START_NAME_HASH_SIZE, 0, 0,
1615 1616
            (hash_get_key) get_stmt_name_hash_key,
            NULL,MYF(0));
1617 1618
}

1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636
int Statement_map::insert(Statement *statement)
{
  int rc= my_hash_insert(&st_hash, (byte *) statement);
  if (rc == 0)
    last_found_statement= statement;
  if (statement->name.str)
  {
    /*
      If there is a statement with the same name, remove it. It is ok to 
      remove old and fail to insert new one at the same time.
    */
    Statement *old_stmt;
    if ((old_stmt= find_by_name(&statement->name)))
      erase(old_stmt); 
    if ((rc= my_hash_insert(&names_hash, (byte*)statement)))
      hash_delete(&st_hash, (byte*)statement);
  }
  return rc;
1637 1638
}

1639

1640 1641 1642 1643 1644 1645
bool select_dumpvar::send_data(List<Item> &items)
{
  List_iterator_fast<Item_func_set_user_var> li(vars);
  Item_func_set_user_var *xx;
  DBUG_ENTER("send_data");

1646 1647 1648 1649 1650
  if (unit->offset_limit_cnt)
  {				          // Using limit offset,count
    unit->offset_limit_cnt--;
    DBUG_RETURN(0);
  }
1651 1652 1653 1654 1655 1656
  if (row_count++) 
  {
    my_error(ER_TOO_MANY_ROWS, MYF(0));
    DBUG_RETURN(1);
  }
  while ((xx=li++))
unknown's avatar
unknown committed
1657 1658
  {
    xx->check();
1659
    xx->update();
unknown's avatar
unknown committed
1660
  }
unknown's avatar
unknown committed
1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676
  DBUG_RETURN(0);
}

bool select_dumpvar::send_eof()
{
  if (row_count)
  {
    ::send_ok(thd,row_count);
    return 0;
  }
  else
  {
    my_error(ER_EMPTY_QUERY,MYF(0));
    return 1;
  }
}
1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687

/****************************************************************************
  TMP_TABLE_PARAM
****************************************************************************/

void TMP_TABLE_PARAM::init()
{
  field_count= sum_func_count= func_count= hidden_field_count= 0;
  group_parts= group_length= group_null_parts= 0;
  quick_group= 1;
}