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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 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; 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#include <drizzled/show.h>
#include <drizzled/lock.h>
#include <drizzled/session.h>
#include <drizzled/statement/rename_table.h>
#include <drizzled/pthread_globals.h>
#include <drizzled/plugin/storage_engine.h>
#include <drizzled/transaction_services.h>
#include <drizzled/sql_lex.h>
#include <drizzled/table/cache.h>
namespace drizzled {
bool statement::RenameTable::execute()
{
TableList *first_table= (TableList *) lex().select_lex.table_list.first;
TableList *all_tables= lex().query_tables;
assert(first_table == all_tables && first_table != 0);
TableList *table;
if (session().inTransaction())
{
my_error(ER_TRANSACTIONAL_DDL_NOT_SUPPORTED, MYF(0));
return true;
}
for (table= first_table; table; table= table->next_local->next_local)
{
TableList old_list, new_list;
/*
we do not need initialize old_list and new_list because we will
come table[0] and table->next[0] there
*/
old_list= table[0];
new_list= table->next_local[0];
}
if (renameTables(first_table))
{
return true;
}
return false;
}
bool statement::RenameTable::renameTables(TableList *table_list)
{
bool error= true;
TableList *ren_table= NULL;
/*
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 (session().inTransaction())
{
my_message(ER_LOCK_OR_ACTIVE_TRANSACTION, ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
return true;
}
if (session().wait_if_global_read_lock(false, true))
return true;
{
boost::mutex::scoped_lock scopedLock(table::Cache::mutex()); /* Rename table lock for exclusive access */
if (not session().lock_table_names_exclusively(table_list))
{
error= false;
ren_table= renameTablesInList(table_list, false);
if (ren_table)
{
/* Rename didn't succeed; rename back the tables in reverse order */
TableList *table;
/* Reverse the table list */
table_list= reverseTableList(table_list);
/* Find the last renamed table */
for (table= table_list;
table->next_local != ren_table;
table= table->next_local->next_local)
{ /* do nothing */ }
table= table->next_local->next_local; // Skip error table
/* Revert to old names */
renameTablesInList(table, true);
error= true;
}
table_list->unlock_table_names();
}
}
/* Lets hope this doesn't fail as the result will be messy */
if (not error)
{
TransactionServices::rawStatement(session(), *session().getQueryString(), *session().schema());
session().my_ok();
}
session().startWaitingGlobalReadLock();
return error;
}
TableList *statement::RenameTable::reverseTableList(TableList *table_list)
{
TableList *prev= NULL;
while (table_list)
{
TableList *next= table_list->next_local;
table_list->next_local= prev;
prev= table_list;
table_list= next;
}
return prev;
}
bool statement::RenameTable::rename(TableList *ren_table,
const char *new_db,
const char *new_table_name,
bool skip_error)
{
bool rc= true;
const char *new_alias, *old_alias;
{
old_alias= ren_table->getTableName();
new_alias= new_table_name;
}
plugin::StorageEngine *engine= NULL;
message::table::shared_ptr table_message;
identifier::Table old_identifier(ren_table->getSchemaName(), old_alias, message::Table::STANDARD);
if (not (table_message= plugin::StorageEngine::getTableMessage(session(), old_identifier)))
{
my_error(ER_TABLE_UNKNOWN, old_identifier);
return true;
}
engine= plugin::StorageEngine::findByName(session(), table_message->engine().name());
identifier::Table new_identifier(new_db, new_alias, message::Table::STANDARD);
if (plugin::StorageEngine::doesTableExist(session(), new_identifier))
{
my_error(ER_TABLE_EXISTS_ERROR, new_identifier);
return 1; // This can't be skipped
}
rc= rename_table(session(), engine, old_identifier, new_identifier);
if (rc && ! skip_error)
return true;
return false;
}
TableList *statement::RenameTable::renameTablesInList(TableList *table_list,
bool skip_error)
{
TableList *ren_table, *new_table;
for (ren_table= table_list; ren_table; ren_table= new_table->next_local)
{
new_table= ren_table->next_local;
if (rename(ren_table, new_table->getSchemaName(), new_table->getTableName(), skip_error))
return ren_table;
}
return 0;
}
} /* namespace drizzled */
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