mariadb/sql/sql_rename.cc
Monty 7332af49e4 - Renaming variables so that they don't shadow others (After this patch one can compile with -Wshadow and get much fewer warnings)
- Changed ER(ER_...) to ER_THD(thd, ER_...) when thd was known or if there was many calls to current_thd in the same function.
- Changed ER(ER_..) to ER_THD_OR_DEFAULT(current_thd, ER...) in some places where current_thd is not necessary defined.
- Removing calls to current_thd when we have access to thd

Part of this is optimization (not calling current_thd when not needed),
but part is bug fixing for error condition when current_thd is not defined
(For example on startup and end of mysqld)

Notable renames done as otherwise a lot of functions would have to be changed:
- In JOIN structure renamed:
   examined_rows -> join_examined_rows
   record_count -> join_record_count
- In Field, renamed new_field() to make_new_field()

Other things:
- Added DBUG_ASSERT(thd == tmp_thd) in Item_singlerow_subselect() just to be safe.
- Removed old 'tab' prefix in JOIN_TAB::save_explain_data() and use members directly
- Added 'thd' as argument to a few functions to avoid calling current_thd.
2015-07-06 20:24:14 +03:00

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C++

/*
Copyright (c) 2000, 2013, Oracle and/or its affiliates.
Copyright (c) 2011, 2013, Monty Program Ab.
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 St, Fifth Floor, Boston, MA 02110-1301 USA */
/*
Atomic rename of table; RENAME TABLE t1 to t2, tmp to t1 [,...]
*/
#include <my_global.h>
#include "sql_priv.h"
#include "unireg.h"
#include "sql_rename.h"
#include "sql_cache.h" // query_cache_*
#include "sql_table.h" // build_table_filename
#include "sql_view.h" // mysql_frm_type, mysql_rename_view
#include "sql_trigger.h"
#include "lock.h" // MYSQL_OPEN_SKIP_TEMPORARY
#include "sql_base.h" // tdc_remove_table, lock_table_names,
#include "sql_handler.h" // mysql_ha_rm_tables
#include "sql_statistics.h"
static TABLE_LIST *rename_tables(THD *thd, TABLE_LIST *table_list,
bool skip_error);
static bool do_rename(THD *thd, TABLE_LIST *ren_table, char *new_db,
char *new_table_name, char *new_table_alias,
bool skip_error);
static TABLE_LIST *reverse_table_list(TABLE_LIST *table_list);
/*
Every two entries in the table_list form a pair of original name and
the new name.
*/
bool mysql_rename_tables(THD *thd, TABLE_LIST *table_list, bool silent)
{
bool error= 1;
bool binlog_error= 0;
TABLE_LIST *ren_table= 0;
int to_table;
char *rename_log_table[2]= {NULL, NULL};
DBUG_ENTER("mysql_rename_tables");
/*
Avoid problems with a rename on a table that we have locked or
if the user is trying to to do this in a transcation context
*/
if (thd->locked_tables_mode || thd->in_active_multi_stmt_transaction())
{
my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
ER_THD(thd, ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
DBUG_RETURN(1);
}
mysql_ha_rm_tables(thd, table_list);
if (logger.is_log_table_enabled(QUERY_LOG_GENERAL) ||
logger.is_log_table_enabled(QUERY_LOG_SLOW))
{
/*
Rules for rename of a log table:
IF 1. Log tables are enabled
AND 2. Rename operates on the log table and nothing is being
renamed to the log table.
DO 3. Throw an error message.
ELSE 4. Perform rename.
*/
for (to_table= 0, ren_table= table_list; ren_table;
to_table= 1 - to_table, ren_table= ren_table->next_local)
{
int log_table_rename;
if ((log_table_rename= check_if_log_table(ren_table, TRUE, NullS)))
{
/*
as we use log_table_rename as an array index, we need it to start
with 0, while QUERY_LOG_SLOW == 1 and QUERY_LOG_GENERAL == 2.
So, we shift the value to start with 0;
*/
log_table_rename--;
if (rename_log_table[log_table_rename])
{
if (to_table)
rename_log_table[log_table_rename]= NULL;
else
{
/*
Two renames of "log_table TO" w/o rename "TO log_table" in
between.
*/
my_error(ER_CANT_RENAME_LOG_TABLE, MYF(0), ren_table->table_name,
ren_table->table_name);
goto err;
}
}
else
{
if (to_table)
{
/*
Attempt to rename a table TO log_table w/o renaming
log_table TO some table.
*/
my_error(ER_CANT_RENAME_LOG_TABLE, MYF(0), ren_table->table_name,
ren_table->table_name);
goto err;
}
else
{
/* save the name of the log table to report an error */
rename_log_table[log_table_rename]= ren_table->table_name;
}
}
}
}
if (rename_log_table[0] || rename_log_table[1])
{
if (rename_log_table[0])
my_error(ER_CANT_RENAME_LOG_TABLE, MYF(0), rename_log_table[0],
rename_log_table[0]);
else
my_error(ER_CANT_RENAME_LOG_TABLE, MYF(0), rename_log_table[1],
rename_log_table[1]);
goto err;
}
}
if (lock_table_names(thd, table_list, 0, thd->variables.lock_wait_timeout,
0))
goto err;
error=0;
/*
An exclusive lock on table names is satisfactory to ensure
no other thread accesses this table.
*/
if ((ren_table=rename_tables(thd,table_list,0)))
{
/* Rename didn't succeed; rename back the tables in reverse order */
TABLE_LIST *table;
/* Reverse the table list */
table_list= reverse_table_list(table_list);
/* Find the last renamed table */
for (table= table_list;
table->next_local != ren_table ;
table= table->next_local->next_local) ;
table= table->next_local->next_local; // Skip error table
/* Revert to old names */
rename_tables(thd, table, 1);
/* Revert the table list (for prepared statements) */
table_list= reverse_table_list(table_list);
error= 1;
}
if (!silent && !error)
{
binlog_error= write_bin_log(thd, TRUE, thd->query(), thd->query_length());
if (!binlog_error)
my_ok(thd);
}
if (!error)
query_cache_invalidate3(thd, table_list, 0);
err:
DBUG_RETURN(error || binlog_error);
}
/*
reverse table list
SYNOPSIS
reverse_table_list()
table_list pointer to table _list
RETURN
pointer to new (reversed) list
*/
static TABLE_LIST *reverse_table_list(TABLE_LIST *table_list)
{
TABLE_LIST *prev= 0;
while (table_list)
{
TABLE_LIST *next= table_list->next_local;
table_list->next_local= prev;
prev= table_list;
table_list= next;
}
return (prev);
}
/*
Rename a single table or a view
SYNPOSIS
do_rename()
thd Thread handle
ren_table A table/view to be renamed
new_db The database to which the table to be moved to
new_table_name The new table/view name
new_table_alias The new table/view alias
skip_error Whether to skip error
DESCRIPTION
Rename a single table or a view.
RETURN
false Ok
true rename failed
*/
static bool
do_rename(THD *thd, TABLE_LIST *ren_table, char *new_db, char *new_table_name,
char *new_table_alias, bool skip_error)
{
int rc= 1;
handlerton *hton;
const char *new_alias, *old_alias;
DBUG_ENTER("do_rename");
if (lower_case_table_names == 2)
{
old_alias= ren_table->alias;
new_alias= new_table_alias;
}
else
{
old_alias= ren_table->table_name;
new_alias= new_table_name;
}
DBUG_ASSERT(new_alias);
if (ha_table_exists(thd, new_db, new_alias))
{
my_error(ER_TABLE_EXISTS_ERROR, MYF(0), new_alias);
DBUG_RETURN(1); // This can't be skipped
}
if (ha_table_exists(thd, ren_table->db, old_alias, &hton) && hton)
{
DBUG_ASSERT(!thd->locked_tables_mode);
tdc_remove_table(thd, TDC_RT_REMOVE_ALL,
ren_table->db, ren_table->table_name, false);
if (hton != view_pseudo_hton)
{
if (!(rc= mysql_rename_table(hton, ren_table->db, old_alias,
new_db, new_alias, 0)))
{
LEX_STRING db_name= { ren_table->db, ren_table->db_length };
LEX_STRING table_name= { ren_table->table_name,
ren_table->table_name_length };
LEX_STRING new_table= { (char *) new_alias, strlen(new_alias) };
(void) rename_table_in_stat_tables(thd, &db_name, &table_name,
&db_name, &new_table);
if ((rc= Table_triggers_list::change_table_name(thd, ren_table->db,
old_alias,
ren_table->table_name,
new_db,
new_alias)))
{
/*
We've succeeded in renaming table's .frm and in updating
corresponding handler data, but have failed to update table's
triggers appropriately. So let us revert operations on .frm
and handler's data and report about failure to rename table.
*/
(void) mysql_rename_table(hton, new_db, new_alias,
ren_table->db, old_alias, NO_FK_CHECKS);
}
}
}
else
{
/*
change of schema is not allowed
except of ALTER ...UPGRADE DATA DIRECTORY NAME command
because a view has valid internal db&table names in this case.
*/
if (thd->lex->sql_command != SQLCOM_ALTER_DB_UPGRADE &&
strcmp(ren_table->db, new_db))
my_error(ER_FORBID_SCHEMA_CHANGE, MYF(0), ren_table->db, new_db);
else
rc= mysql_rename_view(thd, new_db, new_alias, ren_table);
}
}
else
{
my_error(ER_NO_SUCH_TABLE, MYF(0), ren_table->db, old_alias);
}
if (rc && !skip_error)
DBUG_RETURN(1);
DBUG_RETURN(0);
}
/*
Rename all tables in list; Return pointer to wrong entry if something goes
wrong. Note that the table_list may be empty!
*/
/*
Rename tables/views in the list
SYNPOSIS
rename_tables()
thd Thread handle
table_list List of tables to rename
skip_error Whether to skip errors
DESCRIPTION
Take a table/view name from and odd list element and rename it to a
the name taken from list element+1. Note that the table_list may be
empty.
RETURN
false Ok
true rename failed
*/
static TABLE_LIST *
rename_tables(THD *thd, TABLE_LIST *table_list, bool skip_error)
{
TABLE_LIST *ren_table, *new_table;
DBUG_ENTER("rename_tables");
for (ren_table= table_list; ren_table; ren_table= new_table->next_local)
{
new_table= ren_table->next_local;
if (do_rename(thd, ren_table, new_table->db, new_table->table_name,
new_table->alias, skip_error))
DBUG_RETURN(ren_table);
}
DBUG_RETURN(0);
}