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/* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008-2009 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/join_table.h>
#include <drizzled/field/blob.h>
#include <drizzled/sql_select.h>
namespace drizzled
{
int JoinTable::joinReadConstTable(optimizer::Position *pos)
{
int error;
Table *Table= this->table;
Table->const_table=1;
Table->null_row=0;
Table->status=STATUS_NO_RECORD;
if (this->type == AM_SYSTEM)
{
if ((error=this->joinReadSystem()))
{ // Info for DESCRIBE
this->info="const row not found";
/* Mark for EXPLAIN that the row was not found */
pos->setFanout(0.0);
pos->clearRefDependMap();
if (! Table->maybe_null || error > 0)
return(error);
}
}
else
{
if (! Table->key_read &&
Table->covering_keys.test(this->ref.key) &&
! Table->no_keyread &&
(int) Table->reginfo.lock_type <= (int) TL_READ_WITH_SHARED_LOCKS)
{
Table->key_read=1;
Table->cursor->extra(HA_EXTRA_KEYREAD);
this->index= this->ref.key;
}
error=join_read_const(this);
if (Table->key_read)
{
Table->key_read=0;
Table->cursor->extra(HA_EXTRA_NO_KEYREAD);
}
if (error)
{
this->info="unique row not found";
/* Mark for EXPLAIN that the row was not found */
pos->setFanout(0.0);
pos->clearRefDependMap();
if (!Table->maybe_null || error > 0)
return(error);
}
}
if (*this->on_expr_ref && !Table->null_row)
{
if ((Table->null_row= test((*this->on_expr_ref)->val_int() == 0)))
Table->mark_as_null_row();
}
if (!Table->null_row)
Table->maybe_null=0;
/* Check appearance of new constant items in Item_equal objects */
Join *Join= this->join;
if (Join->conds)
update_const_equal_items(Join->conds, this);
TableList *tbl;
for (tbl= Join->select_lex->leaf_tables; tbl; tbl= tbl->next_leaf)
{
TableList *embedded;
TableList *embedding= tbl;
do
{
embedded= embedding;
if (embedded->on_expr)
update_const_equal_items(embedded->on_expr, this);
embedding= embedded->getEmbedding();
}
while (embedding &&
embedding->getNestedJoin()->join_list.head() == embedded);
}
return(0);
}
void JoinTable::readCachedRecord()
{
unsigned char *pos;
uint32_t length;
bool last_record;
CacheField *copy,*end_field;
last_record= this->cache.record_nr++ == this->cache.ptr_record;
pos= this->cache.pos;
for (copy= this->cache.field, end_field= copy+this->cache.fields;
copy < end_field;
copy++)
{
if (copy->blob_field)
{
if (last_record)
{
copy->blob_field->set_image(pos, copy->length+sizeof(char*),
copy->blob_field->charset());
pos+=copy->length+sizeof(char*);
}
else
{
copy->blob_field->set_ptr(pos, pos+copy->length);
pos+=copy->length+copy->blob_field->get_length();
}
}
else
{
if (copy->strip)
{
length= uint2korr(pos);
memcpy(copy->str, pos+2, length);
memset(copy->str+length, ' ', copy->length-length);
pos+= 2 + length;
}
else
{
memcpy(copy->str,pos,copy->length);
pos+=copy->length;
}
}
}
this->cache.pos=pos;
}
int JoinTable::joinReadSystem()
{
Table *Table= this->table;
int error;
if (Table->status & STATUS_GARBAGE) // If first read
{
if ((error=Table->cursor->read_first_row(table->getInsertRecord(),
Table->getShare()->getPrimaryKey())))
{
if (error != HA_ERR_END_OF_FILE)
return Table->report_error(error);
this->table->mark_as_null_row();
Table->emptyRecord(); // Make empty record
return -1;
}
Table->storeRecord();
}
else if (!Table->status) // Only happens with left join
Table->restoreRecord(); // restore old record
Table->null_row=0;
return Table->status ? -1 : 0;
}
} /* namespace drizzled */
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