/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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; either version 2 of the License, or
(at your option) any later version.
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 */
/*
Atomic rename of table; RENAME TABLE t1 to t2, tmp to t1 [,...]
*/
#include "mysql_priv.h"
#include "sql_trigger.h"
static TABLE_LIST *rename_tables(THD *thd, TABLE_LIST *table_list,
bool skip_error);
static TABLE_LIST *reverse_table_list(TABLE_LIST *table_list);
/*
Every second entry in the table_list is the original name and every
second entry is the new name.
*/
bool mysql_rename_tables(THD *thd, TABLE_LIST *table_list)
{
bool error= 1;
TABLE_LIST *ren_table= 0;
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 || thd->active_transaction())
{
my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
DBUG_RETURN(1);
}
if (wait_if_global_read_lock(thd,0,1))
DBUG_RETURN(1);
VOID(pthread_mutex_lock(&LOCK_open));
if (lock_table_names(thd, table_list))
goto err;
error=0;
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;
}
/* Lets hope this doesn't fail as the result will be messy */
if (!error)
{
if (mysql_bin_log.is_open())
{
thd->clear_error();
Query_log_event qinfo(thd, thd->query, thd->query_length, 0, FALSE);
mysql_bin_log.write(&qinfo);
}
send_ok(thd);
}
unlock_table_names(thd, table_list, (TABLE_LIST*) 0);
err:
pthread_mutex_unlock(&LOCK_open);
start_waiting_global_read_lock(thd);
DBUG_RETURN(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
*/
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;
char name[FN_REFLEN];
const char *new_alias, *old_alias;
frm_type_enum frm_type;
db_type table_type;
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;
}
sprintf(name,"%s/%s/%s%s",mysql_data_home,
new_db, new_alias, reg_ext);
unpack_filename(name, name);
if (!access(name,F_OK))
{
my_error(ER_TABLE_EXISTS_ERROR, MYF(0), new_alias);
DBUG_RETURN(1); // This can't be skipped
}
sprintf(name,"%s/%s/%s%s",mysql_data_home,
ren_table->db, old_alias,
reg_ext);
unpack_filename(name, name);
frm_type= mysql_frm_type(thd, name, &table_type);
switch (frm_type)
{
case FRMTYPE_TABLE:
{
if (table_type == DB_TYPE_UNKNOWN)
my_error(ER_FILE_NOT_FOUND, MYF(0), name, my_errno);
else
{
if (!(rc= mysql_rename_table(table_type, ren_table->db, old_alias,
new_db, new_alias)))
{
if ((rc= Table_triggers_list::change_table_name(thd, ren_table->db,
old_alias,
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(table_type, new_db, new_alias,
ren_table->db, old_alias);
}
}
}
break;
}
case FRMTYPE_VIEW:
/* change of schema is not allowed */
if (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_alias, ren_table);
break;
default:
DBUG_ASSERT(0); // should never happen
case FRMTYPE_ERROR:
my_error(ER_FILE_NOT_FOUND, MYF(0), name, my_errno);
break;
}
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);
}