~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 <drizzled/function/str/trim.h>

namespace drizzled

{

String *Item_func_ltrim::val_str(String *str)

{

  assert(fixed == 1);

  char buff[MAX_FIELD_WIDTH], *ptr, *end;

  String tmp(buff,sizeof(buff),system_charset_info);

  String *res, *remove_str;

  uint32_t remove_length;

  res= args[0]->val_str(str);

  if ((null_value=args[0]->null_value))

    return 0;

  remove_str= &remove;                          /* Default value. */

  if (arg_count == 2)

  {

    remove_str= args[1]->val_str(&tmp);

    if ((null_value= args[1]->null_value))

      return 0;

  }

  if ((remove_length= remove_str->length()) == 0 ||

      remove_length > res->length())

    return res;

  ptr= (char*) res->ptr();

  end= ptr+res->length();

  if (remove_length == 1)

  {

    char chr=(*remove_str)[0];

    while (ptr != end && *ptr == chr)

      ptr++;

  }

  else

  {

    const char *r_ptr=remove_str->ptr();

    end-=remove_length;

    while (ptr <= end && !memcmp(ptr, r_ptr, remove_length))

      ptr+=remove_length;

    end+=remove_length;

  }

  if (ptr == res->ptr())

    return res;

  tmp_value.set(*res,(uint) (ptr - res->ptr()),(uint) (end-ptr));

  return &tmp_value;

}

String *Item_func_rtrim::val_str(String *str)

{

  assert(fixed == 1);

  char buff[MAX_FIELD_WIDTH], *ptr, *end;

  String tmp(buff, sizeof(buff), system_charset_info);

  String *res, *remove_str;

  uint32_t remove_length;

  res= args[0]->val_str(str);

  if ((null_value=args[0]->null_value))

    return 0;

  remove_str= &remove;                          /* Default value. */

  if (arg_count == 2)

  {

    remove_str= args[1]->val_str(&tmp);

    if ((null_value= args[1]->null_value))

      return 0;

  }

  if ((remove_length= remove_str->length()) == 0 ||

      remove_length > res->length())

    return res;

  ptr= (char*) res->ptr();

  end= ptr+res->length();

  char *p=ptr;

  register uint32_t l;

  if (remove_length == 1)

  {

    char chr=(*remove_str)[0];

    if (use_mb(res->charset()))

    {

      while (ptr < end)

      {

        if ((l=my_ismbchar(res->charset(), ptr,end))) ptr+=l,p=ptr;

        else ++ptr;

      }

      ptr=p;

    }

    while (ptr != end  && end[-1] == chr)

      end--;

  }

  else

  {

    const char *r_ptr=remove_str->ptr();

    if (use_mb(res->charset()))

    {

loop:

      while (ptr + remove_length < end)

      {

        if ((l=my_ismbchar(res->charset(), ptr,end))) ptr+=l;

        else ++ptr;

      }

      if (ptr + remove_length == end && !memcmp(ptr,r_ptr,remove_length))

      {

        end-=remove_length;

        ptr=p;

        goto loop;

      }

    }

    else

    {

      while (ptr + remove_length <= end &&

          !memcmp(end-remove_length, r_ptr, remove_length))

        end-=remove_length;

    }

  }

  if (end == res->ptr()+res->length())

    return res;

  tmp_value.set(*res,0,(uint) (end-res->ptr()));

  return &tmp_value;

}

String *Item_func_trim::val_str(String *str)

{

  assert(fixed == 1);

  char buff[MAX_FIELD_WIDTH], *ptr, *end;

  const char *r_ptr;

  String tmp(buff, sizeof(buff), system_charset_info);

  String *res, *remove_str;

  uint32_t remove_length;

  res= args[0]->val_str(str);

  if ((null_value=args[0]->null_value))

    return 0;

  remove_str= &remove;                          /* Default value. */

  if (arg_count == 2)

  {

    remove_str= args[1]->val_str(&tmp);

    if ((null_value= args[1]->null_value))

      return 0;

  }

  if ((remove_length= remove_str->length()) == 0 ||

      remove_length > res->length())

    return res;

  ptr= (char*) res->ptr();

  end= ptr+res->length();

  r_ptr= remove_str->ptr();

  while (ptr+remove_length <= end && !memcmp(ptr,r_ptr,remove_length))

    ptr+=remove_length;

  if (use_mb(res->charset()))

  {

    char *p=ptr;

    register uint32_t l;

 loop:

    while (ptr + remove_length < end)

    {

      if ((l=my_ismbchar(res->charset(), ptr,end))) ptr+=l;

      else ++ptr;

    }

    if (ptr + remove_length == end && !memcmp(ptr,r_ptr,remove_length))

    {

      end-=remove_length;

      ptr=p;

      goto loop;

    }

    ptr=p;

  }

  else

  {

    while (ptr + remove_length <= end &&

	   !memcmp(end-remove_length,r_ptr,remove_length))

      end-=remove_length;

  }

  if (ptr == res->ptr() && end == ptr+res->length())

    return res;

  tmp_value.set(*res,(uint) (ptr - res->ptr()),(uint) (end-ptr));

  return &tmp_value;

}

void Item_func_trim::fix_length_and_dec()

{

  max_length= args[0]->max_length;

  if (arg_count == 1)

  {

    collation.set(args[0]->collation);

    remove.set_charset(collation.collation);

    remove.set_ascii(" ",1);

  }

  else

  {

    // Handle character set for args[1] and args[0].

    // Note that we pass args[1] as the first item, and args[0] as the second.

    if (agg_arg_charsets(collation, &args[1], 2, MY_COLL_CMP_CONV, -1))

      return;

  }

}

void Item_func_trim::print(String *str, enum_query_type query_type)

{

  if (arg_count == 1)

  {

    Item_func::print(str, query_type);

    return;

  }

  str->append(Item_func_trim::func_name());

  str->append('(');

  str->append(mode_name());

  str->append(' ');

  args[1]->print(str, query_type);

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

  args[0]->print(str, query_type);

  str->append(')');

}

} /* namespace drizzled */