~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 "mysql_priv.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=',';

ulonglong find_set(TYPELIB *lib, const char *str, uint length, CHARSET_INFO *cs,

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

{

  CHARSET_INFO *strip= cs ? cs : &my_charset_latin1;

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

  ulonglong found= 0;

  *err_pos= 0;                  // No error yet

  if (str != end)

  {

    const char *start= str;    

    for (;;)

    {

      const char *pos= start;

      uint var_len;

      int mblen= 1;

      if (cs && cs->mbminlen > 1)

      {

        for ( ; pos < end; pos+= mblen)

        {

          my_wc_t wc;

          if ((mblen= cs->cset->mb_wc(cs, &wc, (const uchar *) pos, 

                                               (const uchar *) end)) < 1)

            mblen= 1; // Not to hang on a wrong multibyte sequence

          if (wc == (my_wc_t) field_separator)

            break;

        }

      }

      else

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

      var_len= (uint) (pos - start);

      uint 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|= ((longlong) 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

*/

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

               bool part_match)

{

  uint found_count=0, found_pos=0;

  const char *end= find+length;

  const char *i;

  const char *j;

  for (uint 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

*/

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

                CHARSET_INFO *cs)

{

  int pos;

  const char *j;

  DBUG_ENTER("find_type2");

  DBUG_PRINT("enter",("x: '%.*s'  lib: 0x%lx", length, x, (long) typelib));

  if (!typelib->count)

  {

    DBUG_PRINT("exit",("no count"));

    DBUG_RETURN(0);

  }

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

  {

    if (!my_strnncoll(cs, (const uchar*) x, length,

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

      DBUG_RETURN(pos+1);

  }

  DBUG_PRINT("exit",("Couldn't find type"));

  DBUG_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 (uint 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'

*/

uint 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_latin1, *ptr) ; ptr++)

    ;

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

    *end_of_word= ptr;

  return res;

}

/*

  Converts a string between character sets

  SYNOPSIS

    strconvert()

    from_cs       source character set

    from          source, a null terminated string

    to            destination buffer

    to_length     destination buffer length

  NOTES

    'to' is always terminated with a '\0' character.

    If there is no enough space to convert whole string,

    only prefix is converted, and terminated with '\0'.

  RETURN VALUES

    result string length

*/

uint strconvert(CHARSET_INFO *from_cs, const char *from,

                CHARSET_INFO *to_cs, char *to, uint to_length, uint *errors)

{

  int cnvres;

  my_wc_t wc;

  char *to_start= to;

  uchar *to_end= (uchar*) to + to_length - 1;

  my_charset_conv_mb_wc mb_wc= from_cs->cset->mb_wc;

  my_charset_conv_wc_mb wc_mb= to_cs->cset->wc_mb;

  uint error_count= 0;

  while (1)

  {

    /*

      Using 'from + 10' is safe:

      - it is enough to scan a single character in any character set.

      - if remaining string is shorter than 10, then mb_wc will return

        with error because of unexpected '\0' character.

    */

    if ((cnvres= (*mb_wc)(from_cs, &wc,

                          (uchar*) from, (uchar*) from + 10)) > 0)

    {

      if (!wc)

        break;

      from+= cnvres;

    }

    else if (cnvres == MY_CS_ILSEQ)

    {

      error_count++;

      from++;

      wc= '?';

    }

    else

      break; // Impossible char.

outp:

    if ((cnvres= (*wc_mb)(to_cs, wc, (uchar*) to, to_end)) > 0)

      to+= cnvres;

    else if (cnvres == MY_CS_ILUNI && wc != '?')

    {

      error_count++;

      wc= '?';

      goto outp;

    }

    else

      break;

  }

  *to= '\0';

  *errors= error_count;

  return (uint32) (to - to_start);

}

/*

  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,

                         CHARSET_INFO * const cs)

{

  const LEX_STRING *pos;

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

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

                               (uchar *) needle->str, needle->length, 0))

    {

      return (pos - haystack);

    }

  return -1;

}