mariadb/storage/heap/ha_heap.cc
Davi Arnaut 5f911fa874 Bug#49938: Failing assertion: inode or deadlock in fsp/fsp0fsp.c
Bug#54678: InnoDB, TRUNCATE, ALTER, I_S SELECT, crash or deadlock

- Incompatible change: truncate no longer resorts to a row by
row delete if the storage engine does not support the truncate
method. Consequently, the count of affected rows does not, in
any case, reflect the actual number of rows.

- Incompatible change: it is no longer possible to truncate a
table that participates as a parent in a foreign key constraint,
unless it is a self-referencing constraint (both parent and child
are in the same table). To work around this incompatible change
and still be able to truncate such tables, disable foreign checks
with SET foreign_key_checks=0 before truncate. Alternatively, if
foreign key checks are necessary, please use a DELETE statement
without a WHERE condition.

Problem description:

The problem was that for storage engines that do not support
truncate table via a external drop and recreate, such as InnoDB
which implements truncate via a internal drop and recreate, the
delete_all_rows method could be invoked with a shared metadata
lock, causing problems if the engine needed exclusive access
to some internal metadata. This problem originated with the
fact that there is no truncate specific handler method, which
ended up leading to a abuse of the delete_all_rows method that
is primarily used for delete operations without a condition.

Solution:

The solution is to introduce a truncate handler method that is
invoked when the engine does not support truncation via a table
drop and recreate. This method is invoked under a exclusive
metadata lock, so that there is only a single instance of the
table when the method is invoked.

Also, the method is not invoked and a error is thrown if
the table is a parent in a non-self-referencing foreign key
relationship. This was necessary to avoid inconsistency as
some integrity checks are bypassed. This is inline with the
fact that truncate is primarily a DDL operation that was
designed to quickly remove all data from a table.
2010-10-06 11:34:28 -03:00

829 lines
23 KiB
C++

/* Copyright (C) 2000-2006 MySQL AB, 2008-2009 Sun Microsystems, Inc
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifdef USE_PRAGMA_IMPLEMENTATION
#pragma implementation // gcc: Class implementation
#endif
#define MYSQL_SERVER 1
#include "sql_priv.h"
#include "probes_mysql.h"
#include "sql_plugin.h"
#include "ha_heap.h"
#include "heapdef.h"
#include "sql_base.h" // enum_tdc_remove_table_type
static handler *heap_create_handler(handlerton *hton,
TABLE_SHARE *table,
MEM_ROOT *mem_root);
static int
heap_prepare_hp_create_info(TABLE *table_arg, bool internal_table,
HP_CREATE_INFO *hp_create_info);
int heap_panic(handlerton *hton, ha_panic_function flag)
{
return hp_panic(flag);
}
int heap_init(void *p)
{
handlerton *heap_hton;
#ifdef HAVE_PSI_INTERFACE
init_heap_psi_keys();
#endif
heap_hton= (handlerton *)p;
heap_hton->state= SHOW_OPTION_YES;
heap_hton->db_type= DB_TYPE_HEAP;
heap_hton->create= heap_create_handler;
heap_hton->panic= heap_panic;
heap_hton->flags= HTON_CAN_RECREATE;
return 0;
}
static handler *heap_create_handler(handlerton *hton,
TABLE_SHARE *table,
MEM_ROOT *mem_root)
{
return new (mem_root) ha_heap(hton, table);
}
/*****************************************************************************
** HEAP tables
*****************************************************************************/
ha_heap::ha_heap(handlerton *hton, TABLE_SHARE *table_arg)
:handler(hton, table_arg), file(0), records_changed(0), key_stat_version(0),
internal_table(0)
{}
static const char *ha_heap_exts[] = {
NullS
};
const char **ha_heap::bas_ext() const
{
return ha_heap_exts;
}
/*
Hash index statistics is updated (copied from HP_KEYDEF::hash_buckets to
rec_per_key) after 1/HEAP_STATS_UPDATE_THRESHOLD fraction of table records
have been inserted/updated/deleted. delete_all_rows() and table flush cause
immediate update.
NOTE
hash index statistics must be updated when number of table records changes
from 0 to non-zero value and vice versa. Otherwise records_in_range may
erroneously return 0 and 'range' may miss records.
*/
#define HEAP_STATS_UPDATE_THRESHOLD 10
int ha_heap::open(const char *name, int mode, uint test_if_locked)
{
internal_table= test(test_if_locked & HA_OPEN_INTERNAL_TABLE);
if (internal_table || (!(file= heap_open(name, mode)) && my_errno == ENOENT))
{
HP_CREATE_INFO create_info;
my_bool created_new_share;
int rc;
file= 0;
if (heap_prepare_hp_create_info(table, internal_table, &create_info))
goto end;
create_info.pin_share= TRUE;
rc= heap_create(name, &create_info, &internal_share, &created_new_share);
my_free(create_info.keydef);
if (rc)
goto end;
implicit_emptied= test(created_new_share);
if (internal_table)
file= heap_open_from_share(internal_share, mode);
else
file= heap_open_from_share_and_register(internal_share, mode);
if (!file)
{
heap_release_share(internal_share, internal_table);
goto end;
}
}
ref_length= sizeof(HEAP_PTR);
/* Initialize variables for the opened table */
set_keys_for_scanning();
/*
We cannot run update_key_stats() here because we do not have a
lock on the table. The 'records' count might just be changed
temporarily at this moment and we might get wrong statistics (Bug
#10178). Instead we request for update. This will be done in
ha_heap::info(), which is always called before key statistics are
used.
*/
key_stat_version= file->s->key_stat_version-1;
end:
return (file ? 0 : 1);
}
int ha_heap::close(void)
{
return internal_table ? hp_close(file) : heap_close(file);
}
/*
Create a copy of this table
DESCRIPTION
Do same as default implementation but use file->s->name instead of
table->s->path. This is needed by Windows where the clone() call sees
'/'-delimited path in table->s->path, while ha_peap::open() was called
with '\'-delimited path.
*/
handler *ha_heap::clone(MEM_ROOT *mem_root)
{
handler *new_handler= get_new_handler(table->s, mem_root, table->s->db_type());
if (new_handler && !new_handler->ha_open(table, file->s->name, table->db_stat,
HA_OPEN_IGNORE_IF_LOCKED))
return new_handler;
return NULL; /* purecov: inspected */
}
/*
Compute which keys to use for scanning
SYNOPSIS
set_keys_for_scanning()
no parameter
DESCRIPTION
Set the bitmap btree_keys, which is used when the upper layers ask
which keys to use for scanning. For each btree index the
corresponding bit is set.
RETURN
void
*/
void ha_heap::set_keys_for_scanning(void)
{
btree_keys.clear_all();
for (uint i= 0 ; i < table->s->keys ; i++)
{
if (table->key_info[i].algorithm == HA_KEY_ALG_BTREE)
btree_keys.set_bit(i);
}
}
void ha_heap::update_key_stats()
{
for (uint i= 0; i < table->s->keys; i++)
{
KEY *key=table->key_info+i;
if (!key->rec_per_key)
continue;
if (key->algorithm != HA_KEY_ALG_BTREE)
{
if (key->flags & HA_NOSAME)
key->rec_per_key[key->key_parts-1]= 1;
else
{
ha_rows hash_buckets= file->s->keydef[i].hash_buckets;
uint no_records= hash_buckets ? (uint) (file->s->records/hash_buckets) : 2;
if (no_records < 2)
no_records= 2;
key->rec_per_key[key->key_parts-1]= no_records;
}
}
}
records_changed= 0;
/* At the end of update_key_stats() we can proudly claim they are OK. */
key_stat_version= file->s->key_stat_version;
}
int ha_heap::write_row(uchar * buf)
{
int res;
ha_statistic_increment(&SSV::ha_write_count);
if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
table->timestamp_field->set_time();
if (table->next_number_field && buf == table->record[0])
{
if ((res= update_auto_increment()))
return res;
}
res= heap_write(file,buf);
if (!res && (++records_changed*HEAP_STATS_UPDATE_THRESHOLD >
file->s->records))
{
/*
We can perform this safely since only one writer at the time is
allowed on the table.
*/
file->s->key_stat_version++;
}
return res;
}
int ha_heap::update_row(const uchar * old_data, uchar * new_data)
{
int res;
ha_statistic_increment(&SSV::ha_update_count);
if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
table->timestamp_field->set_time();
res= heap_update(file,old_data,new_data);
if (!res && ++records_changed*HEAP_STATS_UPDATE_THRESHOLD >
file->s->records)
{
/*
We can perform this safely since only one writer at the time is
allowed on the table.
*/
file->s->key_stat_version++;
}
return res;
}
int ha_heap::delete_row(const uchar * buf)
{
int res;
ha_statistic_increment(&SSV::ha_delete_count);
res= heap_delete(file,buf);
if (!res && table->s->tmp_table == NO_TMP_TABLE &&
++records_changed*HEAP_STATS_UPDATE_THRESHOLD > file->s->records)
{
/*
We can perform this safely since only one writer at the time is
allowed on the table.
*/
file->s->key_stat_version++;
}
return res;
}
int ha_heap::index_read_map(uchar *buf, const uchar *key,
key_part_map keypart_map,
enum ha_rkey_function find_flag)
{
MYSQL_INDEX_READ_ROW_START(table_share->db.str, table_share->table_name.str);
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_key_count);
int error = heap_rkey(file,buf,active_index, key, keypart_map, find_flag);
table->status = error ? STATUS_NOT_FOUND : 0;
MYSQL_INDEX_READ_ROW_DONE(error);
return error;
}
int ha_heap::index_read_last_map(uchar *buf, const uchar *key,
key_part_map keypart_map)
{
MYSQL_INDEX_READ_ROW_START(table_share->db.str, table_share->table_name.str);
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_key_count);
int error= heap_rkey(file, buf, active_index, key, keypart_map,
HA_READ_PREFIX_LAST);
table->status= error ? STATUS_NOT_FOUND : 0;
MYSQL_INDEX_READ_ROW_DONE(error);
return error;
}
int ha_heap::index_read_idx_map(uchar *buf, uint index, const uchar *key,
key_part_map keypart_map,
enum ha_rkey_function find_flag)
{
MYSQL_INDEX_READ_ROW_START(table_share->db.str, table_share->table_name.str);
ha_statistic_increment(&SSV::ha_read_key_count);
int error = heap_rkey(file, buf, index, key, keypart_map, find_flag);
table->status = error ? STATUS_NOT_FOUND : 0;
MYSQL_INDEX_READ_ROW_DONE(error);
return error;
}
int ha_heap::index_next(uchar * buf)
{
MYSQL_INDEX_READ_ROW_START(table_share->db.str, table_share->table_name.str);
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_next_count);
int error=heap_rnext(file,buf);
table->status=error ? STATUS_NOT_FOUND: 0;
MYSQL_INDEX_READ_ROW_DONE(error);
return error;
}
int ha_heap::index_prev(uchar * buf)
{
MYSQL_INDEX_READ_ROW_START(table_share->db.str, table_share->table_name.str);
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_prev_count);
int error=heap_rprev(file,buf);
table->status=error ? STATUS_NOT_FOUND: 0;
MYSQL_INDEX_READ_ROW_DONE(error);
return error;
}
int ha_heap::index_first(uchar * buf)
{
MYSQL_INDEX_READ_ROW_START(table_share->db.str, table_share->table_name.str);
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_first_count);
int error=heap_rfirst(file, buf, active_index);
table->status=error ? STATUS_NOT_FOUND: 0;
MYSQL_INDEX_READ_ROW_DONE(error);
return error;
}
int ha_heap::index_last(uchar * buf)
{
MYSQL_INDEX_READ_ROW_START(table_share->db.str, table_share->table_name.str);
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_last_count);
int error=heap_rlast(file, buf, active_index);
table->status=error ? STATUS_NOT_FOUND: 0;
MYSQL_INDEX_READ_ROW_DONE(error);
return error;
}
int ha_heap::rnd_init(bool scan)
{
return scan ? heap_scan_init(file) : 0;
}
int ha_heap::rnd_next(uchar *buf)
{
MYSQL_READ_ROW_START(table_share->db.str, table_share->table_name.str,
TRUE);
ha_statistic_increment(&SSV::ha_read_rnd_next_count);
int error=heap_scan(file, buf);
table->status=error ? STATUS_NOT_FOUND: 0;
MYSQL_READ_ROW_DONE(error);
return error;
}
int ha_heap::rnd_pos(uchar * buf, uchar *pos)
{
int error;
HEAP_PTR heap_position;
MYSQL_READ_ROW_START(table_share->db.str, table_share->table_name.str,
FALSE);
ha_statistic_increment(&SSV::ha_read_rnd_count);
memcpy(&heap_position, pos, sizeof(HEAP_PTR));
error=heap_rrnd(file, buf, heap_position);
table->status=error ? STATUS_NOT_FOUND: 0;
MYSQL_READ_ROW_DONE(error);
return error;
}
void ha_heap::position(const uchar *record)
{
*(HEAP_PTR*) ref= heap_position(file); // Ref is aligned
}
int ha_heap::info(uint flag)
{
HEAPINFO hp_info;
(void) heap_info(file,&hp_info,flag);
errkey= hp_info.errkey;
stats.records= hp_info.records;
stats.deleted= hp_info.deleted;
stats.mean_rec_length= hp_info.reclength;
stats.data_file_length= hp_info.data_length;
stats.index_file_length= hp_info.index_length;
stats.max_data_file_length= hp_info.max_records * hp_info.reclength;
stats.delete_length= hp_info.deleted * hp_info.reclength;
if (flag & HA_STATUS_AUTO)
stats.auto_increment_value= hp_info.auto_increment;
/*
If info() is called for the first time after open(), we will still
have to update the key statistics. Hoping that a table lock is now
in place.
*/
if (key_stat_version != file->s->key_stat_version)
update_key_stats();
return 0;
}
int ha_heap::extra(enum ha_extra_function operation)
{
return heap_extra(file,operation);
}
int ha_heap::reset()
{
return heap_reset(file);
}
int ha_heap::delete_all_rows()
{
heap_clear(file);
if (table->s->tmp_table == NO_TMP_TABLE)
{
/*
We can perform this safely since only one writer at the time is
allowed on the table.
*/
file->s->key_stat_version++;
}
return 0;
}
int ha_heap::truncate()
{
int error= delete_all_rows();
return error ? error : reset_auto_increment(0);
}
int ha_heap::reset_auto_increment(ulonglong value)
{
file->s->auto_increment= value;
return 0;
}
int ha_heap::external_lock(THD *thd, int lock_type)
{
return 0; // No external locking
}
/*
Disable indexes.
SYNOPSIS
disable_indexes()
mode mode of operation:
HA_KEY_SWITCH_NONUNIQ disable all non-unique keys
HA_KEY_SWITCH_ALL disable all keys
HA_KEY_SWITCH_NONUNIQ_SAVE dis. non-uni. and make persistent
HA_KEY_SWITCH_ALL_SAVE dis. all keys and make persistent
DESCRIPTION
Disable indexes and clear keys to use for scanning.
IMPLEMENTATION
HA_KEY_SWITCH_NONUNIQ is not implemented.
HA_KEY_SWITCH_NONUNIQ_SAVE is not implemented with HEAP.
HA_KEY_SWITCH_ALL_SAVE is not implemented with HEAP.
RETURN
0 ok
HA_ERR_WRONG_COMMAND mode not implemented.
*/
int ha_heap::disable_indexes(uint mode)
{
int error;
if (mode == HA_KEY_SWITCH_ALL)
{
if (!(error= heap_disable_indexes(file)))
set_keys_for_scanning();
}
else
{
/* mode not implemented */
error= HA_ERR_WRONG_COMMAND;
}
return error;
}
/*
Enable indexes.
SYNOPSIS
enable_indexes()
mode mode of operation:
HA_KEY_SWITCH_NONUNIQ enable all non-unique keys
HA_KEY_SWITCH_ALL enable all keys
HA_KEY_SWITCH_NONUNIQ_SAVE en. non-uni. and make persistent
HA_KEY_SWITCH_ALL_SAVE en. all keys and make persistent
DESCRIPTION
Enable indexes and set keys to use for scanning.
The indexes might have been disabled by disable_index() before.
The function works only if both data and indexes are empty,
since the heap storage engine cannot repair the indexes.
To be sure, call handler::delete_all_rows() before.
IMPLEMENTATION
HA_KEY_SWITCH_NONUNIQ is not implemented.
HA_KEY_SWITCH_NONUNIQ_SAVE is not implemented with HEAP.
HA_KEY_SWITCH_ALL_SAVE is not implemented with HEAP.
RETURN
0 ok
HA_ERR_CRASHED data or index is non-empty. Delete all rows and retry.
HA_ERR_WRONG_COMMAND mode not implemented.
*/
int ha_heap::enable_indexes(uint mode)
{
int error;
if (mode == HA_KEY_SWITCH_ALL)
{
if (!(error= heap_enable_indexes(file)))
set_keys_for_scanning();
}
else
{
/* mode not implemented */
error= HA_ERR_WRONG_COMMAND;
}
return error;
}
/*
Test if indexes are disabled.
SYNOPSIS
indexes_are_disabled()
no parameters
RETURN
0 indexes are not disabled
1 all indexes are disabled
[2 non-unique indexes are disabled - NOT YET IMPLEMENTED]
*/
int ha_heap::indexes_are_disabled(void)
{
return heap_indexes_are_disabled(file);
}
THR_LOCK_DATA **ha_heap::store_lock(THD *thd,
THR_LOCK_DATA **to,
enum thr_lock_type lock_type)
{
if (lock_type != TL_IGNORE && file->lock.type == TL_UNLOCK)
file->lock.type=lock_type;
*to++= &file->lock;
return to;
}
/*
We have to ignore ENOENT entries as the HEAP table is created on open and
not when doing a CREATE on the table.
*/
int ha_heap::delete_table(const char *name)
{
int error= heap_delete_table(name);
return error == ENOENT ? 0 : error;
}
void ha_heap::drop_table(const char *name)
{
file->s->delete_on_close= 1;
close();
}
int ha_heap::rename_table(const char * from, const char * to)
{
return heap_rename(from,to);
}
ha_rows ha_heap::records_in_range(uint inx, key_range *min_key,
key_range *max_key)
{
KEY *key=table->key_info+inx;
if (key->algorithm == HA_KEY_ALG_BTREE)
return hp_rb_records_in_range(file, inx, min_key, max_key);
if (!min_key || !max_key ||
min_key->length != max_key->length ||
min_key->length != key->key_length ||
min_key->flag != HA_READ_KEY_EXACT ||
max_key->flag != HA_READ_AFTER_KEY)
return HA_POS_ERROR; // Can only use exact keys
if (stats.records <= 1)
return stats.records;
/* Assert that info() did run. We need current statistics here. */
DBUG_ASSERT(key_stat_version == file->s->key_stat_version);
return key->rec_per_key[key->key_parts-1];
}
static int
heap_prepare_hp_create_info(TABLE *table_arg, bool internal_table,
HP_CREATE_INFO *hp_create_info)
{
uint key, parts, mem_per_row= 0, keys= table_arg->s->keys;
uint auto_key= 0, auto_key_type= 0;
ha_rows max_rows;
HP_KEYDEF *keydef;
HA_KEYSEG *seg;
TABLE_SHARE *share= table_arg->s;
bool found_real_auto_increment= 0;
bzero(hp_create_info, sizeof(*hp_create_info));
for (key= parts= 0; key < keys; key++)
parts+= table_arg->key_info[key].key_parts;
if (!(keydef= (HP_KEYDEF*) my_malloc(keys * sizeof(HP_KEYDEF) +
parts * sizeof(HA_KEYSEG),
MYF(MY_WME))))
return my_errno;
seg= reinterpret_cast<HA_KEYSEG*>(keydef + keys);
for (key= 0; key < keys; key++)
{
KEY *pos= table_arg->key_info+key;
KEY_PART_INFO *key_part= pos->key_part;
KEY_PART_INFO *key_part_end= key_part + pos->key_parts;
keydef[key].keysegs= (uint) pos->key_parts;
keydef[key].flag= (pos->flags & (HA_NOSAME | HA_NULL_ARE_EQUAL));
keydef[key].seg= seg;
switch (pos->algorithm) {
case HA_KEY_ALG_UNDEF:
case HA_KEY_ALG_HASH:
keydef[key].algorithm= HA_KEY_ALG_HASH;
mem_per_row+= sizeof(char*) * 2; // = sizeof(HASH_INFO)
break;
case HA_KEY_ALG_BTREE:
keydef[key].algorithm= HA_KEY_ALG_BTREE;
mem_per_row+=sizeof(TREE_ELEMENT)+pos->key_length+sizeof(char*);
break;
default:
DBUG_ASSERT(0); // cannot happen
}
for (; key_part != key_part_end; key_part++, seg++)
{
Field *field= key_part->field;
if (pos->algorithm == HA_KEY_ALG_BTREE)
seg->type= field->key_type();
else
{
if ((seg->type = field->key_type()) != (int) HA_KEYTYPE_TEXT &&
seg->type != HA_KEYTYPE_VARTEXT1 &&
seg->type != HA_KEYTYPE_VARTEXT2 &&
seg->type != HA_KEYTYPE_VARBINARY1 &&
seg->type != HA_KEYTYPE_VARBINARY2)
seg->type= HA_KEYTYPE_BINARY;
}
seg->start= (uint) key_part->offset;
seg->length= (uint) key_part->length;
seg->flag= key_part->key_part_flag;
if (field->flags & (ENUM_FLAG | SET_FLAG))
seg->charset= &my_charset_bin;
else
seg->charset= field->charset_for_protocol();
if (field->null_ptr)
{
seg->null_bit= field->null_bit;
seg->null_pos= (uint) (field->null_ptr - (uchar*) table_arg->record[0]);
}
else
{
seg->null_bit= 0;
seg->null_pos= 0;
}
if (field->flags & AUTO_INCREMENT_FLAG &&
table_arg->found_next_number_field &&
key == share->next_number_index)
{
/*
Store key number and type for found auto_increment key
We have to store type as seg->type can differ from it
*/
auto_key= key+ 1;
auto_key_type= field->key_type();
}
}
}
mem_per_row+= MY_ALIGN(share->reclength + 1, sizeof(char*));
if (table_arg->found_next_number_field)
{
keydef[share->next_number_index].flag|= HA_AUTO_KEY;
found_real_auto_increment= share->next_number_key_offset == 0;
}
hp_create_info->auto_key= auto_key;
hp_create_info->auto_key_type= auto_key_type;
hp_create_info->max_table_size=current_thd->variables.max_heap_table_size;
hp_create_info->with_auto_increment= found_real_auto_increment;
hp_create_info->internal_table= internal_table;
max_rows= (ha_rows) (hp_create_info->max_table_size / mem_per_row);
if (share->max_rows && share->max_rows < max_rows)
max_rows= share->max_rows;
hp_create_info->max_records= (ulong) max_rows;
hp_create_info->min_records= (ulong) share->min_rows;
hp_create_info->keys= share->keys;
hp_create_info->reclength= share->reclength;
hp_create_info->keydef= keydef;
return 0;
}
int ha_heap::create(const char *name, TABLE *table_arg,
HA_CREATE_INFO *create_info)
{
int error;
my_bool created;
HP_CREATE_INFO hp_create_info;
error= heap_prepare_hp_create_info(table_arg, internal_table,
&hp_create_info);
if (error)
return error;
hp_create_info.auto_increment= (create_info->auto_increment_value ?
create_info->auto_increment_value - 1 : 0);
error= heap_create(name, &hp_create_info, &internal_share, &created);
my_free(hp_create_info.keydef);
DBUG_ASSERT(file == 0);
return (error);
}
void ha_heap::update_create_info(HA_CREATE_INFO *create_info)
{
table->file->info(HA_STATUS_AUTO);
if (!(create_info->used_fields & HA_CREATE_USED_AUTO))
create_info->auto_increment_value= stats.auto_increment_value;
}
void ha_heap::get_auto_increment(ulonglong offset, ulonglong increment,
ulonglong nb_desired_values,
ulonglong *first_value,
ulonglong *nb_reserved_values)
{
ha_heap::info(HA_STATUS_AUTO);
*first_value= stats.auto_increment_value;
/* such table has only table-level locking so reserves up to +inf */
*nb_reserved_values= ULONGLONG_MAX;
}
bool ha_heap::check_if_incompatible_data(HA_CREATE_INFO *info,
uint table_changes)
{
/* Check that auto_increment value was not changed */
if ((info->used_fields & HA_CREATE_USED_AUTO &&
info->auto_increment_value != 0) ||
table_changes == IS_EQUAL_NO ||
table_changes & IS_EQUAL_PACK_LENGTH) // Not implemented yet
return COMPATIBLE_DATA_NO;
return COMPATIBLE_DATA_YES;
}
struct st_mysql_storage_engine heap_storage_engine=
{ MYSQL_HANDLERTON_INTERFACE_VERSION };
mysql_declare_plugin(heap)
{
MYSQL_STORAGE_ENGINE_PLUGIN,
&heap_storage_engine,
"MEMORY",
"MySQL AB",
"Hash based, stored in memory, useful for temporary tables",
PLUGIN_LICENSE_GPL,
heap_init,
NULL,
0x0100, /* 1.0 */
NULL, /* status variables */
NULL, /* system variables */
NULL /* config options */
}
mysql_declare_plugin_end;