~drizzle-trunk/drizzle/development

/* Copyright (C) 2003 MySQL AB

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/* Some useful string utility functions used by the MySQL server */

#include <drizzled/server_includes.h>

/*

  Return bitmap for strings used in a set

  SYNOPSIS

  find_set()

  lib			Strings in set

  str			Strings of set-strings separated by ','

  err_pos		If error, set to point to start of wrong set string

  err_len		If error, set to the length of wrong set string

  set_warning		Set to 1 if some string in set couldn't be used

  NOTE

    We delete all end space from str before comparison

  RETURN

    bitmap of all sets found in x.

    set_warning is set to 1 if there was any sets that couldn't be set

*/

static const char field_separator=',';

uint64_t find_set(TYPELIB *lib, const char *str, uint32_t length,

                  const CHARSET_INFO * const cs,

                  char **err_pos, uint32_t *err_len, bool *set_warning)

{

  const CHARSET_INFO * const strip= cs ? cs : &my_charset_utf8_general_ci;

  const char *end= str + strip->cset->lengthsp(strip, str, length);

  uint64_t found= 0;

  *err_pos= 0;                  // No error yet

  if (str != end)

  {

    const char *start= str;

    for (;;)

    {

      const char *pos= start;

      uint32_t var_len;

      int mblen= 1;

      for (; pos != end && *pos != field_separator; pos++) 

      {}

      var_len= (uint32_t) (pos - start);

      uint32_t find= cs ? find_type2(lib, start, var_len, cs) :

                      find_type(lib, start, var_len, (bool) 0);

      if (!find)

      {

        *err_pos= (char*) start;

        *err_len= var_len;

        *set_warning= 1;

      }

      else

        found|= ((int64_t) 1 << (find - 1));

      if (pos >= end)

        break;

      start= pos + mblen;

    }

  }

  return found;

}

/*

  Function to find a string in a TYPELIB

  (Same format as mysys/typelib.c)

  SYNOPSIS

   find_type()

   lib			TYPELIB (struct of pointer to values + count)

   find			String to find

   length		Length of string to find

   part_match		Allow part matching of value

 RETURN

  0 error

  > 0 position in TYPELIB->type_names +1

*/

uint32_t find_type(const TYPELIB *lib, const char *find, uint32_t length,

               bool part_match)

{

  uint32_t found_count=0, found_pos=0;

  const char *end= find+length;

  const char *i;

  const char *j;

  for (uint32_t pos=0 ; (j=lib->type_names[pos++]) ; )

  {

    for (i=find ; i != end &&

	   my_toupper(system_charset_info,*i) ==

	   my_toupper(system_charset_info,*j) ; i++, j++) ;

    if (i == end)

    {

      if (! *j)

	return(pos);

      found_count++;

      found_pos= pos;

    }

  }

  return(found_count == 1 && part_match ? found_pos : 0);

}

/*

  Find a string in a list of strings according to collation

  SYNOPSIS

   find_type2()

   lib			TYPELIB (struct of pointer to values + count)

   x			String to find

   length               String length

   cs			Character set + collation to use for comparison

  NOTES

  RETURN

    0	No matching value

    >0  Offset+1 in typelib for matched string

*/

uint32_t find_type2(const TYPELIB *typelib, const char *x, uint32_t length,

                const CHARSET_INFO * const cs)

{

  int pos;

  const char *j;

  if (!typelib->count)

  {

    return(0);

  }

  for (pos=0 ; (j=typelib->type_names[pos]) ; pos++)

  {

    if (!my_strnncoll(cs, (const unsigned char*) x, length,

                          (const unsigned char*) j, typelib->type_lengths[pos]))

      return(pos+1);

  }

  return(0);

} /* find_type */

/*

  Un-hex all elements in a typelib

  SYNOPSIS

   unhex_type2()

   interval       TYPELIB (struct of pointer to values + lengths + count)

  NOTES

  RETURN

    N/A

*/

void unhex_type2(TYPELIB *interval)

{

  for (uint32_t pos= 0; pos < interval->count; pos++)

  {

    char *from, *to;

    for (from= to= (char*) interval->type_names[pos]; *from; )

    {

      /*

        Note, hexchar_to_int(*from++) doesn't work

        one some compilers, e.g. IRIX. Looks like a compiler

        bug in inline functions in combination with arguments

        that have a side effect. So, let's use from[0] and from[1]

        and increment 'from' by two later.

      */

      *to++= (char) (hexchar_to_int(from[0]) << 4) +

                     hexchar_to_int(from[1]);

      from+= 2;

    }

    interval->type_lengths[pos] /= 2;

  }

}

/*

  Check if the first word in a string is one of the ones in TYPELIB

  SYNOPSIS

    check_word()

    lib		TYPELIB

    val		String to check

    end		End of input

    end_of_word	Store value of last used byte here if we found word

  RETURN

    0	 No matching value

    > 1  lib->type_names[#-1] matched

	 end_of_word will point to separator character/end in 'val'

*/

uint32_t check_word(TYPELIB *lib, const char *val, const char *end,

		const char **end_of_word)

{

  int res;

  const char *ptr;

  /* Fiend end of word */

  for (ptr= val ; ptr < end && my_isalpha(&my_charset_utf8_general_ci, *ptr) ; ptr++)

    ;

  if ((res=find_type(lib, val, (uint32_t) (ptr - val), 1)) > 0)

    *end_of_word= ptr;

  return res;

}

/*

  Searches for a LEX_STRING in an LEX_STRING array.

  SYNOPSIS

    find_string_in_array()

      heap    The array

      needle  The string to search for

  NOTE

    The last LEX_STRING in the array should have str member set to NULL

  RETURN VALUES

    -1   Not found

    >=0  Ordinal position

*/

int find_string_in_array(LEX_STRING * const haystack, LEX_STRING * const needle,

                         const CHARSET_INFO * const cs)

{

  const LEX_STRING *pos;

  for (pos= haystack; pos->str; pos++)

    if (!cs->coll->strnncollsp(cs, (unsigned char *) pos->str, pos->length,

                               (unsigned char *) needle->str, needle->length, 0))

    {

      return (pos - haystack);

    }

  return -1;

}