~drizzle-trunk/drizzle/development

/* -*- 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 "config.h"

#include <float.h>

#include <drizzled/function/get_user_var.h>

#include <drizzled/item/null.h>

#include <drizzled/sql_parse.h>

#include <drizzled/session.h>

String *

Item_func_get_user_var::val_str(String *str)

{

  assert(fixed == 1);

  if (!var_entry)

    return((String*) 0);                        // No such variable

  return(var_entry->val_str(&null_value, str, decimals));

}

double Item_func_get_user_var::val_real()

{

  assert(fixed == 1);

  if (!var_entry)

    return 0.0;                                 // No such variable

  return (var_entry->val_real(&null_value));

}

my_decimal *Item_func_get_user_var::val_decimal(my_decimal *dec)

{

  assert(fixed == 1);

  if (!var_entry)

    return 0;

  return var_entry->val_decimal(&null_value, dec);

}

int64_t Item_func_get_user_var::val_int()

{

  assert(fixed == 1);

  if (!var_entry)

    return 0L;                          // No such variable

  return (var_entry->val_int(&null_value));

}

void Item_func_get_user_var::fix_length_and_dec()

{

  Session *session=current_session;

  maybe_null=1;

  decimals=NOT_FIXED_DEC;

  max_length=MAX_BLOB_WIDTH;

  var_entry= session->getVariable(name, false);

  /*

    If the variable didn't exist it has been created as a STRING-type.

    'var_entry' is NULL only if there occured an error during the call to

    get_var_with_binlog.

  */

  if (var_entry)

  {

    m_cached_result_type= var_entry->type;

    unsigned_flag= var_entry->unsigned_flag;

    max_length= var_entry->length;

    collation.set(var_entry->collation);

    switch(m_cached_result_type) 

    {

    case REAL_RESULT:

      max_length= DBL_DIG + 8;

      break;

    case INT_RESULT:

      max_length= MAX_BIGINT_WIDTH;

      decimals=0;

      break;

    case STRING_RESULT:

      max_length= MAX_BLOB_WIDTH;

      break;

    case DECIMAL_RESULT:

      max_length= DECIMAL_MAX_STR_LENGTH;

      decimals= DECIMAL_MAX_SCALE;

      break;

    case ROW_RESULT:                            // Keep compiler happy

    default:

      assert(0);

      break;

    }

  }

  else

  {

    collation.set(&my_charset_bin, DERIVATION_IMPLICIT);

    null_value= 1;

    m_cached_result_type= STRING_RESULT;

    max_length= MAX_BLOB_WIDTH;

  }

}

bool Item_func_get_user_var::const_item() const

{

  return (!var_entry || current_session->query_id != var_entry->update_query_id);

}

enum Item_result Item_func_get_user_var::result_type() const

{

  return m_cached_result_type;

}

void Item_func_get_user_var::print(String *str,

                                   enum_query_type )

{

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

  str->append(name.str,name.length);

  str->append(')');

}

bool Item_func_get_user_var::eq(const Item *item,

                                bool ) const

{

  /* Assume we don't have rtti */

  if (this == item)

    return 1;					// Same item is same.

  /* Check if other type is also a get_user_var() object */

  if (item->type() != FUNC_ITEM ||

      ((Item_func*) item)->functype() != functype())

    return 0;

  Item_func_get_user_var *other=(Item_func_get_user_var*) item;

  return (name.length == other->name.length &&

	  !memcmp(name.str, other->name.str, name.length));

}