~drizzle-trunk/drizzle/development

/* Copyright (C) 2000 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */

#include <config.h>

#include <drizzled/charset.h>

#include <drizzled/error.h>

#include <drizzled/internal/m_string.h>

#include <drizzled/configmake.h>

#include <vector>

#include <drizzled/visibility.h>

using namespace std;

namespace drizzled {

/*

  We collect memory in this vector that we free on delete.

*/

static vector<unsigned char*> memory_vector;

/*

  The code below implements this functionality:

    - Initializing charset related structures

    - Loading dynamic charsets

    - Searching for a proper charset_info_st

      using charset name, collation name or collation ID

    - Setting server default character set

*/

bool my_charset_same(const charset_info_st *cs1, const charset_info_st *cs2)

{

  return cs1 == cs2 || not strcmp(cs1->csname, cs2->csname);

}

static uint get_collation_number_internal(const char *name)

{

  for (charset_info_st **cs= all_charsets;

       cs < all_charsets+array_elements(all_charsets)-1;

       cs++)

  {

    if ( cs[0] && cs[0]->name && !my_strcasecmp(&my_charset_utf8_general_ci, cs[0]->name, name))

    {

      return cs[0]->number;

    }

  }

  return 0;

}

static unsigned char* cs_alloc(size_t size)

{

  memory_vector.push_back(new unsigned char[size]);

  return memory_vector.back();

}

static void init_state_maps(charset_info_st *cs)

{

  cs->state_map= cs_alloc(256);

  cs->ident_map= cs_alloc(256);

  unsigned char *state_map= cs->state_map;

  unsigned char *ident_map= cs->ident_map;

  /* Fill state_map with states to get a faster parser */

  for (int i= 0; i < 256; i++)

  {

    if (my_isalpha(cs,i))

      state_map[i]= MY_LEX_IDENT;

    else if (my_isdigit(cs,i))

      state_map[i]= MY_LEX_NUMBER_IDENT;

    else if (my_mbcharlen(cs, i)>1)

      state_map[i]= MY_LEX_IDENT;

    else if (my_isspace(cs,i))

      state_map[i]= MY_LEX_SKIP;

    else

      state_map[i]= MY_LEX_CHAR;

  }

  state_map['_']=state_map['$']= MY_LEX_IDENT;

  state_map['\'']= MY_LEX_STRING;

  state_map['.']= MY_LEX_REAL_OR_POINT;

  state_map['>']=state_map['=']=state_map['!']=  MY_LEX_CMP_OP;

  state_map['<']=  MY_LEX_LONG_CMP_OP;

  state_map['&']=state_map['|']= MY_LEX_BOOL;

  state_map['#']= MY_LEX_COMMENT;

  state_map[';']= MY_LEX_SEMICOLON;

  state_map[':']= MY_LEX_SET_VAR;

  state_map[0]= MY_LEX_EOL;

  state_map['\\']=  MY_LEX_ESCAPE;

  state_map['/']=  MY_LEX_LONG_COMMENT;

  state_map['*']=  MY_LEX_END_LONG_COMMENT;

  state_map['@']=  MY_LEX_USER_END;

  state_map['`']=  MY_LEX_USER_VARIABLE_DELIMITER;

  state_map['"']=  MY_LEX_STRING_OR_DELIMITER;

  /*

    Create a second map to make it faster to find identifiers

  */

  for (int i= 0; i < 256; i++)

  {

    ident_map[i]= state_map[i] == MY_LEX_IDENT || state_map[i] == MY_LEX_NUMBER_IDENT;

  }

  /* Special handling of hex and binary strings */

  state_map['x']= state_map['X']=  MY_LEX_IDENT_OR_HEX;

  state_map['b']= state_map['B']=  MY_LEX_IDENT_OR_BIN;

}

static bool charset_initialized= false;

DRIZZLED_API charset_info_st *all_charsets[256];

const DRIZZLED_API charset_info_st *default_charset_info = &my_charset_utf8_general_ci;

void add_compiled_collation(charset_info_st * cs)

{

  all_charsets[cs->number]= cs;

  cs->state|= MY_CS_AVAILABLE;

}

static void init_available_charsets(myf myflags)

{

  /*

    We have to use charset_initialized to not lock on THR_LOCK_charset

    inside get_internal_charset...

  */

  if (charset_initialized)

    return;

  memset(&all_charsets, 0, sizeof(all_charsets));

  init_compiled_charsets(myflags);

  /* Copy compiled charsets */

  for (charset_info_st**cs= all_charsets;

    cs < all_charsets+array_elements(all_charsets)-1;

    cs++)

  {

    if (*cs && cs[0]->ctype)

      init_state_maps(*cs);

  }

  charset_initialized= true;

}

void free_charsets()

{

  charset_initialized= false;

  while (not memory_vector.empty())

  {

    delete[] memory_vector.back();

    memory_vector.pop_back();

  }

}

uint32_t get_collation_number(const char *name)

{

  init_available_charsets(MYF(0));

  return get_collation_number_internal(name);

}

uint32_t get_charset_number(const char *charset_name, uint32_t cs_flags)

{

  charset_info_st **cs;

  init_available_charsets(MYF(0));

  for (cs= all_charsets;

       cs < all_charsets+array_elements(all_charsets)-1 ;

       cs++)

  {

    if ( cs[0] && cs[0]->csname && (cs[0]->state & cs_flags) && !my_strcasecmp(&my_charset_utf8_general_ci, cs[0]->csname, charset_name))

      return cs[0]->number;

  }

  return 0;

}

const char *get_charset_name(uint32_t charset_number)

{

  init_available_charsets(MYF(0));

  const charset_info_st *cs= all_charsets[charset_number];

  if (cs && (cs->number == charset_number) && cs->name )

    return cs->name;

  return "?";   /* this mimics find_type() */

}

static const charset_info_st *get_internal_charset(uint32_t cs_number)

{

  charset_info_st *cs;

  /*

    To make things thread safe we are not allowing other threads to interfere

    while we may changing the cs_info_table

  */

  if ((cs= all_charsets[cs_number]))

  {

    if (!(cs->state & MY_CS_COMPILED) && !(cs->state & MY_CS_LOADED))

    {

      assert(0);

    }

    cs= (cs->state & MY_CS_AVAILABLE) ? cs : NULL;

  }

  if (cs && !(cs->state & MY_CS_READY))

  {

    if ((cs->cset->init && cs->cset->init(cs, cs_alloc)) ||

        (cs->coll->init && cs->coll->init(cs, cs_alloc)))

      cs= NULL;

    else

      cs->state|= MY_CS_READY;

  }

  return cs;

}

const charset_info_st *get_charset(uint32_t cs_number)

{

  if (cs_number == default_charset_info->number)

    return default_charset_info;

  init_available_charsets(MYF(0));	/* If it isn't initialized */

  if (!cs_number || cs_number >= array_elements(all_charsets)-1)

    return NULL;

  return get_internal_charset(cs_number);

}

const charset_info_st *get_charset_by_name(const char *cs_name)

{

  init_available_charsets(MYF(0));	/* If it isn't initialized */

  uint32_t cs_number= get_collation_number(cs_name);

  return cs_number ? get_internal_charset(cs_number) : NULL;

}

const charset_info_st *get_charset_by_csname(const char *cs_name, uint32_t cs_flags)

{

  init_available_charsets(MYF(0));	/* If it isn't initialized */

  uint32_t cs_number= get_charset_number(cs_name, cs_flags);

  return cs_number ? get_internal_charset(cs_number) : NULL;

}

/*

  Escape apostrophes by doubling them up

  SYNOPSIS

    escape_quotes_for_drizzle()

    charset_info        Charset of the strings

    to                  Buffer for escaped string

    to_length           Length of destination buffer, or 0

    from                The string to escape

    length              The length of the string to escape

  DESCRIPTION

    This escapes the contents of a string by doubling up any apostrophes that

    it contains. This is used when the NO_BACKSLASH_ESCAPES SQL_MODE is in

    effect on the server.

  NOTE

    To be consistent with escape_string_for_mysql(), to_length may be 0 to

    mean "big enough"

  RETURN VALUES

    UINT32_MAX  The escaped string did not fit in the to buffer

    >=0         The length of the escaped string

*/

size_t escape_quotes_for_drizzle(const charset_info_st *charset_info,

                                 char *to, size_t to_length,

                                 const char *from, size_t length)

{

  const char *to_start= to;

  const char *end, *to_end=to_start + (to_length ? to_length-1 : 2*length);

  bool overflow= false;

  bool use_mb_flag= use_mb(charset_info);

  for (end= from + length; from < end; from++)

  {

    int tmp_length;

    if (use_mb_flag && (tmp_length= my_ismbchar(charset_info, from, end)))

    {

      if (to + tmp_length > to_end)

      {

        overflow= true;

        break;

      }

      while (tmp_length--)

	*to++= *from++;

      from--;

      continue;

    }

    /*

      We don't have the same issue here with a non-multi-byte character being

      turned into a multi-byte character by the addition of an escaping

      character, because we are only escaping the ' character with itself.

     */

    if (*from == '\'')

    {

      if (to + 2 > to_end)

      {

        overflow= true;

        break;

      }

      *to++= '\'';

      *to++= '\'';

    }

    else

    {

      if (to + 1 > to_end)

      {

        overflow= true;

        break;

      }

      *to++= *from;

    }

  }

  *to= 0;

  return overflow ? UINT32_MAX : to - to_start;

}

} /* namespace drizzled */