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/* 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; 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 <config.h>
#include <string>
#include <drizzled/error.h>
#include <drizzled/table_list.h>
#include <drizzled/item.h>
#include <drizzled/item/field.h>
#include <drizzled/nested_join.h>
#include <drizzled/sql_lex.h>
#include <drizzled/sql_select.h>
using namespace std;
namespace drizzled {
void TableList::set_insert_values()
{
if (table)
{
table->insert_values.resize(table->getShare()->rec_buff_length);
}
}
bool TableList::is_leaf_for_name_resolution() const
{
return is_natural_join || is_join_columns_complete || not nested_join;
}
TableList *TableList::find_underlying_table(Table *table_to_find)
{
/* is this real table and table which we are looking for? */
if (table == table_to_find)
return this;
return NULL;
}
bool TableList::isCartesian() const
{
return false;
}
bool TableList::placeholder()
{
return derived || (create && !table->getDBStat()) || !table;
}
/*
* The right-most child of a nested table reference is the first
* element in the list of children because the children are inserted
* in reverse order.
*/
TableList *TableList::last_leaf_for_name_resolution()
{
TableList *cur_table_ref= this;
NestedJoin *cur_nested_join;
if (is_leaf_for_name_resolution())
return this;
assert(nested_join);
for (cur_nested_join= nested_join;
cur_nested_join;
cur_nested_join= cur_table_ref->nested_join)
{
cur_table_ref= &cur_nested_join->join_list.front();
/*
If the current nested is a RIGHT JOIN, the operands in
'join_list' are in reverse order, thus the last operand is in the
end of the list.
*/
if ((cur_table_ref->outer_join & JOIN_TYPE_RIGHT))
{
List<TableList>::iterator it(cur_nested_join->join_list.begin());
TableList *next;
cur_table_ref= it++;
while ((next= it++))
cur_table_ref= next;
}
if (cur_table_ref->is_leaf_for_name_resolution())
break;
}
return cur_table_ref;
}
/*
* The left-most child of a nested table reference is the last element
* in the list of children because the children are inserted in
* reverse order.
*/
TableList *TableList::first_leaf_for_name_resolution()
{
TableList *cur_table_ref= NULL;
NestedJoin *cur_nested_join;
if (is_leaf_for_name_resolution())
return this;
assert(nested_join);
for (cur_nested_join= nested_join;
cur_nested_join;
cur_nested_join= cur_table_ref->nested_join)
{
List<TableList>::iterator it(cur_nested_join->join_list.begin());
cur_table_ref= it++;
/*
If the current nested join is a RIGHT JOIN, the operands in
'join_list' are in reverse order, thus the first operand is
already at the front of the list. Otherwise the first operand
is in the end of the list of join operands.
*/
if (!(cur_table_ref->outer_join & JOIN_TYPE_RIGHT))
{
TableList *next;
while ((next= it++))
cur_table_ref= next;
}
if (cur_table_ref->is_leaf_for_name_resolution())
break;
}
return cur_table_ref;
}
Item_subselect *TableList::containing_subselect()
{
return (select_lex ? select_lex->master_unit()->item : 0);
}
bool TableList::process_index_hints(Table *tbl)
{
/* initialize the result variables */
tbl->keys_in_use_for_query= tbl->keys_in_use_for_group_by=
tbl->keys_in_use_for_order_by= tbl->getShare()->keys_in_use;
/* index hint list processing */
if (index_hints)
{
key_map index_join[INDEX_HINT_FORCE + 1];
key_map index_order[INDEX_HINT_FORCE + 1];
key_map index_group[INDEX_HINT_FORCE + 1];
bool have_empty_use_join= false, have_empty_use_order= false,
have_empty_use_group= false;
List_iterator <Index_hint> iter(index_hints->begin());
/* initialize temporary variables used to collect hints of each kind */
for (int type= INDEX_HINT_IGNORE; type <= INDEX_HINT_FORCE; type++)
{
index_join[type].reset();
index_order[type].reset();
index_group[type].reset();
}
/* iterate over the hints list */
while (Index_hint* hint= iter++)
{
/* process empty USE INDEX () */
if (hint->type == INDEX_HINT_USE && !hint->key_name)
{
if (hint->clause & INDEX_HINT_MASK_JOIN)
{
index_join[hint->type].reset();
have_empty_use_join= true;
}
if (hint->clause & INDEX_HINT_MASK_ORDER)
{
index_order[hint->type].reset();
have_empty_use_order= true;
}
if (hint->clause & INDEX_HINT_MASK_GROUP)
{
index_group[hint->type].reset();
have_empty_use_group= true;
}
continue;
}
/*
Check if an index with the given name exists and get his offset in
the keys bitmask for the table
*/
uint32_t pos= tbl->getShare()->doesKeyNameExist(hint->key_name);
if (pos == UINT32_MAX)
{
my_error(ER_KEY_DOES_NOT_EXITS, MYF(0), hint->key_name, alias);
return 1;
}
/* add to the appropriate clause mask */
if (hint->clause & INDEX_HINT_MASK_JOIN)
index_join[hint->type].set(pos);
if (hint->clause & INDEX_HINT_MASK_ORDER)
index_order[hint->type].set(pos);
if (hint->clause & INDEX_HINT_MASK_GROUP)
index_group[hint->type].set(pos);
}
/* cannot mix USE INDEX and FORCE INDEX */
if ((index_join[INDEX_HINT_FORCE].any() ||
index_order[INDEX_HINT_FORCE].any() ||
index_group[INDEX_HINT_FORCE].any()) &&
(index_join[INDEX_HINT_USE].any() || have_empty_use_join ||
index_order[INDEX_HINT_USE].any() || have_empty_use_order ||
index_group[INDEX_HINT_USE].any() || have_empty_use_group))
{
my_error(ER_WRONG_USAGE, MYF(0), index_hint_type_name[INDEX_HINT_USE], index_hint_type_name[INDEX_HINT_FORCE]);
return 1;
}
/* process FORCE INDEX as USE INDEX with a flag */
if (index_join[INDEX_HINT_FORCE].any() ||
index_order[INDEX_HINT_FORCE].any() ||
index_group[INDEX_HINT_FORCE].any())
{
tbl->force_index= true;
index_join[INDEX_HINT_USE]|= index_join[INDEX_HINT_FORCE];
index_order[INDEX_HINT_USE]|= index_order[INDEX_HINT_FORCE];
index_group[INDEX_HINT_USE]|= index_group[INDEX_HINT_FORCE];
}
/* apply USE INDEX */
if (index_join[INDEX_HINT_USE].any() || have_empty_use_join)
tbl->keys_in_use_for_query&= index_join[INDEX_HINT_USE];
if (index_order[INDEX_HINT_USE].any() || have_empty_use_order)
tbl->keys_in_use_for_order_by&= index_order[INDEX_HINT_USE];
if (index_group[INDEX_HINT_USE].any() || have_empty_use_group)
tbl->keys_in_use_for_group_by&= index_group[INDEX_HINT_USE];
/* apply IGNORE INDEX */
key_map_subtract(tbl->keys_in_use_for_query, index_join[INDEX_HINT_IGNORE]);
key_map_subtract(tbl->keys_in_use_for_order_by, index_order[INDEX_HINT_IGNORE]);
key_map_subtract(tbl->keys_in_use_for_group_by, index_group[INDEX_HINT_IGNORE]);
}
/* make sure covering_keys don't include indexes disabled with a hint */
tbl->covering_keys&= tbl->keys_in_use_for_query;
return 0;
}
void TableList::print(Session *session, String *str)
{
if (nested_join)
{
str->append('(');
print_join(session, str, &nested_join->join_list);
str->append(')');
}
else
{
const char *cmp_name; // Name to compare with alias
if (derived)
{
// A derived table
str->append('(');
derived->print(str);
str->append(')');
cmp_name= ""; // Force printing of alias
}
else
{
// A normal table
str->append_identifier(str_ref(schema));
str->append('.');
str->append_identifier(str_ref(table_name));
cmp_name= table_name;
}
if (table_alias_charset->strcasecmp(cmp_name, alias) && alias && alias[0])
{
str->append(' ');
str->append_identifier(boost::to_lower_copy(string(alias)));
}
if (index_hints)
{
List<Index_hint>::iterator it(index_hints->begin());
while (Index_hint* hint= it++)
{
str->append(STRING_WITH_LEN(" "));
hint->print(*str);
}
}
}
}
} /* namespace drizzled */
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