~drizzle-trunk/drizzle/development

492.3.9 by Lee
code clean move Item_func_abs, Item_func_int_exp, Item_func_ln, Item_func_log to functions directory
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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
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 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
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 *
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 *  Copyright (C) 2008 Sun Microsystems
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 *
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 *  This program is free software; you can redistribute it and/or modify
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 *  it under the terms of the GNU General Public License as published by
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 *  the Free Software Foundation; version 2 of the License.
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 *
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 *  This program is distributed in the hope that it will be useful,
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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 *  GNU General Public License for more details.
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 *
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 *  You should have received a copy of the GNU General Public License
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 *  along with this program; if not, write to the Free Software
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 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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 */
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#include <drizzled/server_includes.h>
642.1.30 by Lee
move math functions to drizzled/function/math directory
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#include <drizzled/function/math/log.h>
492.3.9 by Lee
code clean move Item_func_abs, Item_func_int_exp, Item_func_ln, Item_func_log to functions directory
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/**
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  Extended but so slower LOG function.
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  We have to check if all values are > zero and first one is not one
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  as these are the cases then result is not a number.
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*/
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double Item_func_log::val_real()
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{
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  assert(fixed == 1);
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  double value= args[0]->val_real();
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  if ((null_value= args[0]->null_value))
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    return 0.0;
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  if (value <= 0.0)
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  {
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    signal_divide_by_null();
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    return 0.0;
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  }
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  if (arg_count == 2)
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  {
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    double value2= args[1]->val_real();
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    if ((null_value= args[1]->null_value))
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      return 0.0;
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    if (value2 <= 0.0 || value == 1.0)
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    {
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      signal_divide_by_null();
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      return 0.0;
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    }
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    return log(value2) / log(value);
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  }
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  return log(value);
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}
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double Item_func_log2::val_real()
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{
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  assert(fixed == 1);
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  double value= args[0]->val_real();
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  if ((null_value=args[0]->null_value))
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    return 0.0;
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  if (value <= 0.0)
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  {
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    signal_divide_by_null();
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    return 0.0;
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  }
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  return log(value) / M_LN2;
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}
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double Item_func_log10::val_real()
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{
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  assert(fixed == 1);
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  double value= args[0]->val_real();
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  if ((null_value= args[0]->null_value))
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    return 0.0;
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  if (value <= 0.0)
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  {
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    signal_divide_by_null();
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    return 0.0;
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  }
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  return log10(value);
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}
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