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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems
*
* 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
*/
#include <drizzled/server_includes.h>
#include CSTDINT_H
#include <drizzled/function/rand.h>
#include <libdrizzle/password.h>
#include <drizzled/session.h>
void Item_func_rand::seed_random(Item *arg)
{
/*
TODO: do not do reinit 'rand' for every execute of PS/SP if
args[0] is a constant.
*/
uint32_t tmp= (uint32_t) arg->val_int();
randominit(rand, (uint32_t) (tmp*0x10001L+55555555L),
(uint32_t) (tmp*0x10000001L));
}
bool Item_func_rand::fix_fields(Session *session,Item **ref)
{
if (Item_real_func::fix_fields(session, ref))
return true;
used_tables_cache|= RAND_TABLE_BIT;
if (arg_count)
{ // Only use argument once in query
/*
No need to send a Rand log event if seed was given eg: RAND(seed),
as it will be replicated in the query as such.
*/
if (!rand && !(rand= (struct rand_struct*)
session->alloc(sizeof(*rand))))
return true;
if (args[0]->const_item())
seed_random (args[0]);
}
else
{
rand= &session->rand;
}
return false;
}
void Item_func_rand::update_used_tables()
{
Item_real_func::update_used_tables();
used_tables_cache|= RAND_TABLE_BIT;
}
double Item_func_rand::val_real()
{
assert(fixed == 1);
if (arg_count && !args[0]->const_item())
seed_random (args[0]);
return my_rnd(rand);
}
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