~drizzle-trunk/drizzle/development

/* 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 {

bool TableList::set_insert_values(memory::Root *)

{

  if (table)

  {

    table->insert_values.resize(table->getShare()->rec_buff_length);

  }

  return false;

}

bool TableList::is_leaf_for_name_resolution()

{

  return (is_natural_join || is_join_columns_complete || !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];

    Index_hint *hint;

    int type;

    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 (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 ((hint= iter++))

    {

      uint32_t pos= 0;

      /* process empty USE INDEX () */

      if (hint->type == INDEX_HINT_USE && !hint->key_name.str)

      {

        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

      */

      if (not tbl->getShare()->doesKeyNameExist(hint->key_name.str, hint->key_name.length, pos))

      {

        my_error(ER_KEY_DOES_NOT_EXITS, MYF(0), hint->key_name.str, 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(db, db_length);

        str->append('.');

      }

      str->append_identifier(table_name, table_name_length);

      cmp_name= table_name;

    }

    if (my_strcasecmp(table_alias_charset, cmp_name, alias))

    {

      if (alias && alias[0])

      {

        str->append(' ');

        string t_alias(alias);

        transform(t_alias.begin(), t_alias.end(), t_alias.begin(), ::tolower);

        str->append_identifier(t_alias.c_str(), t_alias.length());

      }

    }

    if (index_hints)

    {

      List<Index_hint>::iterator it(index_hints->begin());

      while (Index_hint* hint= it++)

      {

        str->append (STRING_WITH_LEN(" "));

        hint->print (session, str);

      }

    }

  }

}

} /* namespace drizzled */