Drizzled Public API Documentation

boolean.cc

00001 /* - mode: c++ c-basic-offset: 2; indent-tabs-mode: nil; -*-
00002  *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
00003  *
00004  *  Copyright (C) 2010 Brian Aker
00005  *
00006  *  This program is free software; you can redistribute it and/or modify
00007  *  it under the terms of the GNU General Public License as published by
00008  *  the Free Software Foundation; either version 2 of the License, or
00009  *  (at your option) any later version.
00010  *
00011  *  This program is distributed in the hope that it will be useful,
00012  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  *  GNU General Public License for more details.
00015  *
00016  *  You should have received a copy of the GNU General Public License
00017  *  along with this program; if not, write to the Free Software
00018  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00019  */
00020 
00021 #include <config.h>
00022 
00023 #include <drizzled/error.h>
00024 #include <drizzled/function/cast/boolean.h>
00025 #include <drizzled/lex_string.h>
00026 #include <drizzled/type/boolean.h>
00027 
00028 namespace drizzled {
00029 namespace function {
00030 namespace cast {
00031 
00032 void Boolean::print(String *str)
00033 {
00034   str->append(STRING_WITH_LEN("cast("));
00035   args[0]->print(str);
00036   str->append(STRING_WITH_LEN(" as boolean)"));
00037 }
00038 
00039 drizzled::String *Boolean::val_str(drizzled::String *value)
00040 {
00041   switch (args[0]->result_type())
00042   {
00043   case STRING_RESULT:
00044     {
00045       drizzled::String _res, *res;
00046 
00047       if (not (res= args[0]->val_str(&_res)))
00048       { 
00049         null_value= true; 
00050         break;
00051       }
00052       null_value= false; 
00053 
00054       bool result;
00055       if (not type::convert(result, *res))
00056       {
00057         my_error(ER_INVALID_CAST_TO_BOOLEAN, MYF(0), res->c_ptr());
00058       }
00059 
00060       return evaluate(result, value);
00061     }
00062 
00063   case REAL_RESULT:
00064   case ROW_RESULT:
00065   case DECIMAL_RESULT:
00066   case INT_RESULT:
00067     {
00068       bool tmp= args[0]->val_bool();
00069       null_value=args[0]->null_value;
00070 
00071       return evaluate(tmp, value);
00072     }
00073   }
00074 
00075   // We should never reach this
00076   return evaluate(false, value);
00077 }
00078 
00079 String *Boolean::evaluate(const bool &result, String *val_buffer)
00080 {
00081   const CHARSET_INFO * const cs= &my_charset_bin;
00082   uint32_t mlength= (5) * cs->mbmaxlen;
00083 
00084   val_buffer->alloc(mlength);
00085   char *buffer=(char*) val_buffer->c_ptr();
00086 
00087   if (result)
00088   {
00089     memcpy(buffer, "TRUE", 4);
00090     val_buffer->length(4);
00091   }
00092   else
00093   {
00094     memcpy(buffer, "FALSE", 5);
00095     val_buffer->length(5);
00096   }
00097 
00098   return val_buffer;
00099 }
00100 
00101 } // namespace cast
00102 } // namespace function
00103 } // namespace drizzled