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/* 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"
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);
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 all tables in list; Return pointer to wrong entry if something goes
wrong. Note that the table_list may be empty!
*/
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)
{
db_type table_type;
char name[FN_REFLEN];
const char *new_alias, *old_alias;
new_table= ren_table->next_local;
if (lower_case_table_names == 2)
{
old_alias= ren_table->alias;
new_alias= new_table->alias;
}
else
{
old_alias= ren_table->real_name;
new_alias= new_table->real_name;
}
sprintf(name,"%s/%s/%s%s",mysql_data_home,
new_table->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(ren_table); // 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);
if ((table_type=get_table_type(name)) == DB_TYPE_UNKNOWN)
{
my_error(ER_FILE_NOT_FOUND, MYF(0), name, my_errno);
if (!skip_error)
DBUG_RETURN(ren_table);
}
else if (mysql_rename_table(table_type,
ren_table->db, old_alias,
new_table->db, new_alias))
{
if (!skip_error)
DBUG_RETURN(ren_table);
}
}
DBUG_RETURN(0);
}
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