/*
   Copyright (c) 2000, 2011, Oracle and/or its affiliates.
   Copyright (c) 2009, 2018, MariaDB Corporation

   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 02110-1335  USA
*/

/*
  Functions to create a unireg form-file from a FIELD and a fieldname-fieldinfo
  struct.
  In the following functions FIELD * is an ordinary field-structure with
  the following exeptions:
    sc_length,typepos,row,kol,dtype,regnr and field need not to be set.
    str is a (long) to record position where 0 is the first position.
*/

#include "sql_priv.h"
#include "unireg.h"
#include "sql_partition.h"                      // struct partition_info
#include "sql_table.h"                          // check_duplicate_warning
#include "sql_class.h"                  // THD, Internal_error_handler
#include "create_options.h"
#include <m_ctype.h>
#include <assert.h>

#define FCOMP			17		/* Bytes for a packed field */

/* threshold for safe_alloca */
#define ALLOCA_THRESHOLD       2048

static uchar * pack_screens(List<Create_field> &create_fields,
			    uint *info_length, uint *screens, bool small_file);
static uint pack_keys(uchar *keybuff,uint key_count, KEY *key_info,
                      ulong data_offset);
static bool pack_header(uchar *forminfo,enum legacy_db_type table_type,
			List<Create_field> &create_fields,
			uint info_length, uint screens, uint table_options,
			ulong data_offset, handler *file);
static uint get_interval_id(uint *,List<Create_field> &, Create_field *);
static bool pack_fields(File file, List<Create_field> &create_fields,
                        ulong data_offset);
static bool make_empty_rec(THD *thd, int file, enum legacy_db_type table_type,
			   uint table_options,
			   List<Create_field> &create_fields,
			   uint reclength, ulong data_offset,
                           handler *handler);

/**
  An interceptor to hijack ER_TOO_MANY_FIELDS error from
  pack_screens and retry again without UNIREG screens.

  XXX: what is a UNIREG  screen?
*/

struct Pack_header_error_handler: public Internal_error_handler
{
  virtual bool handle_condition(THD *thd,
                                uint sql_errno,
                                const char* sqlstate,
                                MYSQL_ERROR::enum_warning_level level,
                                const char* msg,
                                MYSQL_ERROR ** cond_hdl);
  bool is_handled;
  Pack_header_error_handler() :is_handled(FALSE) {}
};


bool
Pack_header_error_handler::
handle_condition(THD *,
                 uint sql_errno,
                 const char*,
                 MYSQL_ERROR::enum_warning_level,
                 const char*,
                 MYSQL_ERROR ** cond_hdl)
{
  *cond_hdl= NULL;
  is_handled= (sql_errno == ER_TOO_MANY_FIELDS);
  return is_handled;
}

/*
  In ALTER TABLE, mysql_create_frm() gets the temporary table name,
  like #sql-3696_2. It's used for error messages, when a table cannot
  be created because of some OS error.
  If there's a user error (like, too long comment), we want to show
  the real table name, though.
*/
static const char *get_real_table_name(const char *table,
                                       List<Create_field> &fields)
{
  const char *real_table_name= table;
  List_iterator<Create_field> it(fields);
  Create_field *field;
  while ((field=it++))
  {
    if (field->field && field->field->table &&
       (real_table_name= field->field->table->s->table_name.str))
      break;
  }
  return real_table_name;
}

/*
  Create a frm (table definition) file

  SYNOPSIS
    mysql_create_frm()
    thd			Thread handler
    file_name		Path for file (including database and .frm)
    db                  Name of database
    table               Name of table
    create_info		create info parameters
    create_fields	Fields to create
    keys		number of keys to create
    key_info		Keys to create
    db_file		Handler to use. May be zero, in which case we use
			create_info->db_type
  RETURN
    false  ok
    true   error
*/

bool mysql_create_frm(THD *thd, const char *file_name,
                      const char *db, const char *table,
		      HA_CREATE_INFO *create_info,
		      List<Create_field> &create_fields,
		      uint keys, KEY *key_info,
		      handler *db_file)
{
  LEX_STRING str_db_type;
  uint reclength, info_length, screens, key_info_length, maxlength, tmp_len, i;
  ulong key_buff_length;
  File file;
  ulong filepos, data_offset;
  uint options_len;
  uchar fileinfo[64],forminfo[288],*keybuff;
  uchar *screen_buff;
  char buff[128];
#ifdef WITH_PARTITION_STORAGE_ENGINE
  partition_info *part_info= thd->work_part_info;
#endif
  Pack_header_error_handler pack_header_error_handler;
  int error;
  DBUG_ENTER("mysql_create_frm");

  DBUG_ASSERT(*fn_rext((char*)file_name)); // Check .frm extension

  if (!(screen_buff=pack_screens(create_fields,&info_length,&screens,0)))
    DBUG_RETURN(1);
  DBUG_ASSERT(db_file != NULL);

 /* If fixed row records, we need one bit to check for deleted rows */
  if (!(create_info->table_options & HA_OPTION_PACK_RECORD))
    create_info->null_bits++;
  data_offset= (create_info->null_bits + 7) / 8;

  thd->push_internal_handler(&pack_header_error_handler);

  error= pack_header(forminfo, ha_legacy_type(create_info->db_type),
                     create_fields,info_length,
                     screens, create_info->table_options,
                     data_offset, db_file);

  thd->pop_internal_handler();

  if (error)
  {
    my_free(screen_buff);
    if (! pack_header_error_handler.is_handled)
      DBUG_RETURN(1);

    // Try again without UNIREG screens (to get more columns)
    if (!(screen_buff=pack_screens(create_fields,&info_length,&screens,1)))
      DBUG_RETURN(1);
    if (pack_header(forminfo, ha_legacy_type(create_info->db_type),
                    create_fields,info_length,
		    screens, create_info->table_options, data_offset, db_file))
    {
      my_free(screen_buff);
      DBUG_RETURN(1);
    }
  }
  reclength=uint2korr(forminfo+266);

  /* Calculate extra data segment length */
  str_db_type= *hton_name(create_info->db_type);
  /* str_db_type */
  create_info->extra_size= (2 + str_db_type.length +
                            2 + create_info->connect_string.length);
  /*
    Partition:
      Length of partition info = 4 byte
      Potential NULL byte at end of partition info string = 1 byte
      Indicator if auto-partitioned table = 1 byte
      => Total 6 byte
  */
  create_info->extra_size+= 6;
#ifdef WITH_PARTITION_STORAGE_ENGINE
  if (part_info)
  {
    create_info->extra_size+= part_info->part_info_len;
  }
#endif

  for (i= 0; i < keys; i++)
  {
    if (key_info[i].parser_name)
      create_info->extra_size+= key_info[i].parser_name->length + 1;
  }

  options_len= engine_table_options_frm_length(create_info->option_list,
                                               create_fields,
                                               keys, key_info);
  DBUG_PRINT("info", ("Options length: %u", options_len));
  if (options_len)
  {
    create_info->table_options|= HA_OPTION_TEXT_CREATE_OPTIONS;
    create_info->extra_size+= (options_len + 4);
  }
  else
    create_info->table_options&= ~HA_OPTION_TEXT_CREATE_OPTIONS;

  /*
    This gives us the byte-position of the character at
    (character-position, not byte-position) TABLE_COMMENT_MAXLEN.
    The trick here is that character-positions start at 0, so the last
    character in a maximum-allowed length string would be at char-pos
    MAXLEN-1; charpos MAXLEN will be the position of the terminator.
    Consequently, bytepos(charpos(MAXLEN)) should be equal to
    comment[length] (which should also be the terminator, or at least
    the first byte after the payload in the strict sense). If this is
    not so (bytepos(charpos(MAXLEN)) comes /before/ the end of the
    string), the string is too long.

    For additional credit, realise that UTF-8 has 1-3 bytes before 6.0,
    and 1-4 bytes in 6.0 (6.0 also has UTF-32).
  */
  tmp_len= system_charset_info->cset->charpos(system_charset_info,
                                              create_info->comment.str,
                                              create_info->comment.str +
                                              create_info->comment.length,
                                              TABLE_COMMENT_MAXLEN);

  if (tmp_len < create_info->comment.length)
  {
    const char *real_table_name= get_real_table_name(table, create_fields);
    if ((thd->variables.sql_mode &
         (MODE_STRICT_TRANS_TABLES | MODE_STRICT_ALL_TABLES)))
    {
      my_error(ER_TOO_LONG_TABLE_COMMENT, MYF(0),
               real_table_name, static_cast<ulong>(TABLE_COMMENT_MAXLEN));
      my_free(screen_buff);
      DBUG_RETURN(1);
    }
    char warn_buff[MYSQL_ERRMSG_SIZE];
    my_snprintf(warn_buff, sizeof(warn_buff), ER(ER_TOO_LONG_TABLE_COMMENT),
                real_table_name, static_cast<ulong>(TABLE_COMMENT_MAXLEN));
    /* do not push duplicate warnings */
    if (!check_duplicate_warning(current_thd, warn_buff, strlen(warn_buff)))
      push_warning(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                   ER_TOO_LONG_TABLE_COMMENT, warn_buff);
    create_info->comment.length= tmp_len;
  }
  /*
    If table comment is longer than TABLE_COMMENT_INLINE_MAXLEN bytes,
    store the comment in an extra segment (up to TABLE_COMMENT_MAXLEN bytes).
    Pre 6.0, the limit was 60 characters, with no extra segment-handling.
  */
  if (create_info->comment.length > TABLE_COMMENT_INLINE_MAXLEN)
  {
    forminfo[46]=255;
    create_info->extra_size+= 2 + create_info->comment.length;
  }
  else{
    strmake((char*) forminfo+47, create_info->comment.str ?
            create_info->comment.str : "", create_info->comment.length);
    forminfo[46]=(uchar) create_info->comment.length;
  }

  if ((file=create_frm(thd, file_name, db, table, reclength, fileinfo,
		       create_info, keys, key_info)) < 0)
  {
    my_free(screen_buff);
    DBUG_RETURN(1);
  }

  key_buff_length= uint4korr(fileinfo+47);
  keybuff=(uchar*) my_malloc(key_buff_length, MYF(0));
  key_info_length= pack_keys(keybuff, keys, key_info, data_offset);

  if (key_info_length > UINT_MAX16)
  {
    my_printf_error(ER_CANT_CREATE_TABLE,
                    "Cannot create table %`s.%`s: index information is too long. "
                    "Decrease number of indexes or use shorter index names or shorter comments.",
                    MYF(0), db, get_real_table_name(table, create_fields));
    goto err;
  }

  /*
    Ensure that there are no forms in this newly created form file.
    Even if the form file exists, create_frm must truncate it to
    ensure one form per form file.
  */
  DBUG_ASSERT(uint2korr(fileinfo+8) == 0);

  if (!(filepos= make_new_entry(file, fileinfo, NULL, "")))
    goto err;
  maxlength=(uint) next_io_size((ulong) (uint2korr(forminfo)+1000));
  int2store(forminfo+2,maxlength);
  int4store(fileinfo+10,(ulong) (filepos+maxlength));
  fileinfo[26]= (uchar) test((create_info->max_rows == 1) &&
			     (create_info->min_rows == 1) && (keys == 0));
  int2store(fileinfo+28,key_info_length);

#ifdef WITH_PARTITION_STORAGE_ENGINE
  if (part_info)
  {
    fileinfo[61]= (uchar) ha_legacy_type(part_info->default_engine_type);
    DBUG_PRINT("info", ("part_db_type = %d", fileinfo[61]));
  }
#endif
  int2store(fileinfo+59,db_file->extra_rec_buf_length());

  if (mysql_file_pwrite(file, fileinfo, 64, 0L, MYF_RW) ||
      mysql_file_pwrite(file, keybuff, key_info_length,
                        (ulong) uint2korr(fileinfo+6), MYF_RW))
    goto err;
  mysql_file_seek(file,
                  (ulong) uint2korr(fileinfo+6) + (ulong) key_buff_length,
                  MY_SEEK_SET, MYF(0));
  if (make_empty_rec(thd,file,ha_legacy_type(create_info->db_type),
                     create_info->table_options,
		     create_fields,reclength, data_offset, db_file))
    goto err;

  int2store(buff, create_info->connect_string.length);
  if (mysql_file_write(file, (const uchar*)buff, 2, MYF(MY_NABP)) ||
      mysql_file_write(file, (const uchar*)create_info->connect_string.str,
               create_info->connect_string.length, MYF(MY_NABP)))
      goto err;

  int2store(buff, str_db_type.length);
  if (mysql_file_write(file, (const uchar*)buff, 2, MYF(MY_NABP)) ||
      mysql_file_write(file, (const uchar*)str_db_type.str,
               str_db_type.length, MYF(MY_NABP)))
    goto err;

#ifdef WITH_PARTITION_STORAGE_ENGINE
  if (part_info)
  {
    char auto_partitioned= part_info->is_auto_partitioned ? 1 : 0;
    int4store(buff, part_info->part_info_len);
    if (mysql_file_write(file, (const uchar*)buff, 4, MYF_RW) ||
        mysql_file_write(file, (const uchar*)part_info->part_info_string,
                 part_info->part_info_len + 1, MYF_RW) ||
        mysql_file_write(file, (const uchar*)&auto_partitioned, 1, MYF_RW))
      goto err;
  }
  else
#endif
  {
    bzero((uchar*) buff, 6);
    if (mysql_file_write(file, (uchar*) buff, 6, MYF_RW))
      goto err;
  }

  for (i= 0; i < keys; i++)
  {
    if (key_info[i].parser_name)
    {
      if (mysql_file_write(file, (const uchar*)key_info[i].parser_name->str,
                           key_info[i].parser_name->length + 1, MYF(MY_NABP)))
        goto err;
    }
  }
  if (forminfo[46] == (uchar)255)
  {
    uchar comment_length_buff[2];
    int2store(comment_length_buff,create_info->comment.length);
    if (mysql_file_write(file, comment_length_buff, 2, MYF(MY_NABP)) ||
        mysql_file_write(file, (uchar*) create_info->comment.str,
                         create_info->comment.length, MYF(MY_NABP)))
      goto err;
  }

  if (options_len)
  {
    uchar *optbuff= (uchar *)my_safe_alloca(options_len + 4, ALLOCA_THRESHOLD);
    my_bool error;
    DBUG_PRINT("info", ("Create options length: %u", options_len));
    if (!optbuff)
      goto err;
    int4store(optbuff, options_len);
    engine_table_options_frm_image(optbuff + 4,
                                   create_info->option_list,
                                   create_fields,
                                   keys, key_info);
    error= my_write(file, optbuff, options_len + 4, MYF_RW);
    my_safe_afree(optbuff, options_len + 4, ALLOCA_THRESHOLD);
    if (error)
      goto err;
  }

  mysql_file_seek(file, filepos, MY_SEEK_SET, MYF(0));
  if (mysql_file_write(file, forminfo, 288, MYF_RW) ||
      mysql_file_write(file, screen_buff, info_length, MYF_RW) ||
      pack_fields(file, create_fields, data_offset))
    goto err;

#ifdef HAVE_CRYPTED_FRM
  if (create_info->password)
  {
    char tmp=2,*disk_buff=0;
    SQL_CRYPT *crypted=new SQL_CRYPT(create_info->password);
    if (!crypted || mysql_file_pwrite(file, &tmp, 1, 26, MYF_RW))// Mark crypted
      goto err;
    uint read_length=uint2korr(forminfo)-256;
    mysql_file_seek(file, filepos+256, MY_SEEK_SET, MYF(0));
    if (read_string(file,(uchar**) &disk_buff,read_length))
      goto err;
    crypted->encode(disk_buff,read_length);
    delete crypted;
    if (mysql_file_pwrite(file, disk_buff, read_length, filepos+256, MYF_RW))
    {
      my_free(disk_buff);
      goto err;
    }
    my_free(disk_buff);
  }
#endif

  my_free(screen_buff);
  my_free(keybuff);

  if (opt_sync_frm && !(create_info->options & HA_LEX_CREATE_TMP_TABLE) &&
      (mysql_file_sync(file, MYF(MY_WME)) ||
       my_sync_dir_by_file(file_name, MYF(MY_WME))))
      goto err2;

  if (mysql_file_close(file, MYF(MY_WME)))
    goto err3;

  {
    /* 
      Restore all UCS2 intervals.
      HEX representation of them is not needed anymore.
    */
    List_iterator<Create_field> it(create_fields);
    Create_field *field;
    while ((field=it++))
    {
      if (field->save_interval)
      {
        field->interval= field->save_interval;
        field->save_interval= 0;
      }
    }
  }
  DBUG_RETURN(0);

err:
  my_free(screen_buff);
  my_free(keybuff);
err2:
  (void) mysql_file_close(file, MYF(MY_WME));
err3:
  mysql_file_delete(key_file_frm, file_name, MYF(0));
  DBUG_RETURN(1);
} /* mysql_create_frm */


/*
  Create a frm (table definition) file and the tables

  SYNOPSIS
    rea_create_table()
    thd			Thread handler
    path		Name of file (including database, without .frm)
    db			Data base name
    table_name		Table name
    create_info		create info parameters
    create_fields	Fields to create
    keys		number of keys to create
    key_info		Keys to create
    file		Handler to use

  RETURN
    0  ok
    1  error
*/

int rea_create_table(THD *thd, const char *path,
                     const char *db, const char *table_name,
                     HA_CREATE_INFO *create_info,
                     List<Create_field> &create_fields,
                     uint keys, KEY *key_info, handler *file)
{
  DBUG_ENTER("rea_create_table");

  char frm_name[FN_REFLEN];
  strxmov(frm_name, path, reg_ext, NullS);
  if (mysql_create_frm(thd, frm_name, db, table_name, create_info,
                       create_fields, keys, key_info, file))

    DBUG_RETURN(1);

  // Make sure mysql_create_frm din't remove extension
  DBUG_ASSERT(*fn_rext(frm_name));
  if (thd->variables.keep_files_on_create)
    create_info->options|= HA_CREATE_KEEP_FILES;
  if (!create_info->frm_only &&
      (file->ha_create_handler_files(path, NULL, CHF_CREATE_FLAG,
                                     create_info) ||
       ha_create_table(thd, path, db, table_name, create_info, 0)))
    goto err_handler;
  DBUG_RETURN(0);

err_handler:
  (void) file->ha_create_handler_files(path, NULL, CHF_DELETE_FLAG, create_info);
  mysql_file_delete(key_file_frm, frm_name, MYF(0));
  DBUG_RETURN(1);
} /* rea_create_table */


	/* Pack screens to a screen for save in a form-file */

static uchar *pack_screens(List<Create_field> &create_fields,
                           uint *info_length, uint *screens,
                           bool small_file)
{
  reg1 uint i;
  uint row,start_row,end_row,fields_on_screen;
  uint length,cols;
  uchar *info,*pos,*start_screen;
  uint fields=create_fields.elements;
  List_iterator<Create_field> it(create_fields);
  DBUG_ENTER("pack_screens");

  start_row=4; end_row=22; cols=80; fields_on_screen=end_row+1-start_row;

  *screens=(fields-1)/fields_on_screen+1;
  length= (*screens) * (SC_INFO_LENGTH+ (cols>> 1)+4);

  Create_field *field;
  while ((field=it++))
    length+=(uint) strlen(field->field_name)+1+TE_INFO_LENGTH+cols/2;

  if (!(info=(uchar*) my_malloc(length,MYF(MY_WME))))
    DBUG_RETURN(0);

  start_screen=0;
  row=end_row;
  pos=info;
  it.rewind();
  for (i=0 ; i < fields ; i++)
  {
    Create_field *cfield=it++;
    if (row++ == end_row)
    {
      if (i)
      {
	length=(uint) (pos-start_screen);
	int2store(start_screen,length);
	start_screen[2]=(uchar) (fields_on_screen+1);
	start_screen[3]=(uchar) (fields_on_screen);
      }
      row=start_row;
      start_screen=pos;
      pos+=4;
      pos[0]= (uchar) start_row-2;	/* Header string */
      pos[1]= (uchar) (cols >> 2);
      pos[2]= (uchar) (cols >> 1) +1;
      strfill((char *) pos+3,(uint) (cols >> 1),' ');
      pos+=(cols >> 1)+4;
    }
    length=(uint) strlen(cfield->field_name);
    if (length > cols-3)
      length=cols-3;

    if (!small_file)
    {
      pos[0]=(uchar) row;
      pos[1]=0;
      pos[2]=(uchar) (length+1);
      pos=(uchar*) strmake((char*) pos+3,cfield->field_name,length)+1;
    }
    cfield->row=(uint8) row;
    cfield->col=(uint8) (length+1);
    cfield->sc_length=(uint8) min(cfield->length,cols-(length+2));
  }
  length=(uint) (pos-start_screen);
  int2store(start_screen,length);
  start_screen[2]=(uchar) (row-start_row+2);
  start_screen[3]=(uchar) (row-start_row+1);

  *info_length=(uint) (pos-info);
  DBUG_RETURN(info);
} /* pack_screens */


	/* Pack keyinfo and keynames to keybuff for save in form-file. */

static uint pack_keys(uchar *keybuff, uint key_count, KEY *keyinfo,
                      ulong data_offset)
{
  uint key_parts,length;
  uchar *pos, *keyname_pos;
  KEY *key,*end;
  KEY_PART_INFO *key_part,*key_part_end;
  DBUG_ENTER("pack_keys");

  pos=keybuff+6;
  key_parts=0;
  for (key=keyinfo,end=keyinfo+key_count ; key != end ; key++)
  {
    int2store(pos, (key->flags ^ HA_NOSAME));
    int2store(pos+2,key->key_length);
    pos[4]= (uchar) key->key_parts;
    pos[5]= (uchar) key->algorithm;
    int2store(pos+6, key->block_size);
    pos+=8;
    key_parts+=key->key_parts;
    DBUG_PRINT("loop", ("flags: %lu  key_parts: %d  key_part: 0x%lx",
                        key->flags, key->key_parts,
                        (long) key->key_part));
    for (key_part=key->key_part,key_part_end=key_part+key->key_parts ;
	 key_part != key_part_end ;
	 key_part++)

    {
      uint offset;
      DBUG_PRINT("loop",("field: %d  startpos: %lu  length: %d",
			 key_part->fieldnr, key_part->offset + data_offset,
                         key_part->length));
      int2store(pos,key_part->fieldnr+1+FIELD_NAME_USED);
      offset= (uint) (key_part->offset+data_offset+1);
      int2store(pos+2, offset);
      pos[4]=0;					// Sort order
      int2store(pos+5,key_part->key_type);
      int2store(pos+7,key_part->length);
      pos+=9;
    }
  }
	/* Save keynames */
  keyname_pos=pos;
  *pos++=(uchar) NAMES_SEP_CHAR;
  for (key=keyinfo ; key != end ; key++)
  {
    uchar *tmp=(uchar*) strmov((char*) pos,key->name);
    *tmp++= (uchar) NAMES_SEP_CHAR;
    *tmp=0;
    pos=tmp;
  }
  *(pos++)=0;
  for (key=keyinfo,end=keyinfo+key_count ; key != end ; key++)
  {
    if (key->flags & HA_USES_COMMENT)
    {
      int2store(pos, key->comment.length);
      uchar *tmp= (uchar*)strnmov((char*) pos+2,key->comment.str,
                                  key->comment.length);
      pos= tmp;
    }
  }

  if (key_count > 127 || key_parts > 127)
  {
    keybuff[0]= (key_count & 0x7f) | 0x80;
    keybuff[1]= key_count >> 7;
    int2store(keybuff+2,key_parts);
  }
  else
  {
    keybuff[0]=(uchar) key_count;
    keybuff[1]=(uchar) key_parts;
    keybuff[2]= keybuff[3]= 0;
  }
  length=(uint) (pos-keyname_pos);
  int2store(keybuff+4,length);
  DBUG_RETURN((uint) (pos-keybuff));
} /* pack_keys */


	/* Make formheader */

static bool pack_header(uchar *forminfo, enum legacy_db_type table_type,
			List<Create_field> &create_fields,
                        uint info_length, uint screens, uint table_options,
                        ulong data_offset, handler *file)
{
  uint length,int_count,int_length,no_empty, int_parts;
  uint time_stamp_pos,null_fields;
  ulong reclength, totlength, n_length, com_length, vcol_info_length;
  DBUG_ENTER("pack_header");

  if (create_fields.elements > MAX_FIELDS)
  {
    my_message(ER_TOO_MANY_FIELDS, ER(ER_TOO_MANY_FIELDS), MYF(0));
    DBUG_RETURN(1);
  }

  totlength= 0L;
  reclength= data_offset;
  no_empty=int_count=int_parts=int_length=time_stamp_pos=null_fields=0;
  com_length=vcol_info_length=0;
  n_length=2L;

	/* Check fields */

  List_iterator<Create_field> it(create_fields);
  Create_field *field;
  while ((field=it++))
  {
    uint tmp_len= system_charset_info->cset->charpos(system_charset_info,
                                                     field->comment.str,
                                                     field->comment.str +
                                                     field->comment.length,
                                                     COLUMN_COMMENT_MAXLEN);
    if (tmp_len < field->comment.length)
    {
      if ((current_thd->variables.sql_mode &
	   (MODE_STRICT_TRANS_TABLES | MODE_STRICT_ALL_TABLES)))
      {
        my_error(ER_TOO_LONG_FIELD_COMMENT, MYF(0), field->field_name,
                 static_cast<ulong>(COLUMN_COMMENT_MAXLEN));
	DBUG_RETURN(1);
      }
      char warn_buff[MYSQL_ERRMSG_SIZE];
      my_snprintf(warn_buff, sizeof(warn_buff), ER(ER_TOO_LONG_FIELD_COMMENT),
                  field->field_name,
                  static_cast<ulong>(COLUMN_COMMENT_MAXLEN));
      /* do not push duplicate warnings */
      if (!check_duplicate_warning(current_thd, warn_buff, strlen(warn_buff)))
        push_warning(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                     ER_TOO_LONG_FIELD_COMMENT, warn_buff);
      field->comment.length= tmp_len;
    }
    if (field->vcol_info)
    {
      uint col_expr_maxlen= field->virtual_col_expr_maxlen();
      tmp_len=
        system_charset_info->cset->charpos(system_charset_info,
                                           field->vcol_info->expr_str.str,
                                           field->vcol_info->expr_str.str +
                                           field->vcol_info->expr_str.length,
                                           col_expr_maxlen);

      if (tmp_len < field->vcol_info->expr_str.length)
      {
        my_error(ER_WRONG_STRING_LENGTH, MYF(0),
                 field->vcol_info->expr_str.str,"VIRTUAL COLUMN EXPRESSION",
                 col_expr_maxlen);
        DBUG_RETURN(1);
      }
      /*
        Sum up the length of the expression string and the length of the
        mandatory header to the total length of info on the defining 
        expressions saved in the frm file for virtual columns.
      */
      vcol_info_length+= field->vcol_info->expr_str.length+
	                 FRM_VCOL_HEADER_SIZE(field->interval!=NULL);
    }

    totlength+= field->length;
    com_length+= field->comment.length;
    if (MTYP_TYPENR(field->unireg_check) == Field::NOEMPTY ||
	field->unireg_check & MTYP_NOEMPTY_BIT)
    {
      field->unireg_check= (Field::utype) ((uint) field->unireg_check |
					   MTYP_NOEMPTY_BIT);
      no_empty++;
    }
    /* 
      We mark first TIMESTAMP field with NOW() in DEFAULT or ON UPDATE 
      as auto-update field.
    */
    if (field->sql_type == MYSQL_TYPE_TIMESTAMP &&
        MTYP_TYPENR(field->unireg_check) != Field::NONE &&
	!time_stamp_pos)
      time_stamp_pos= (uint) field->offset+ (uint) data_offset + 1;
    length=field->pack_length;
    if ((uint) field->offset+ (uint) data_offset+ length > reclength)
      reclength=(uint) (field->offset+ data_offset + length);
    n_length+= (ulong) strlen(field->field_name)+1;
    field->interval_id=0;
    field->save_interval= 0;
    if (field->interval)
    {
      uint old_int_count=int_count;

      if (field->charset->mbminlen > 1)
      {
        /* 
          Escape UCS2 intervals using HEX notation to avoid
          problems with delimiters between enum elements.
          As the original representation is still needed in 
          the function make_empty_rec to create a record of
          filled with default values it is saved in save_interval
          The HEX representation is created from this copy.
        */
        field->save_interval= field->interval;
        field->interval= (TYPELIB*) sql_alloc(sizeof(TYPELIB));
        *field->interval= *field->save_interval; 
        field->interval->type_names= 
          (const char **) sql_alloc(sizeof(char*) * 
				    (field->interval->count+1));
        field->interval->type_names[field->interval->count]= 0;
        field->interval->type_lengths=
          (uint *) sql_alloc(sizeof(uint) * field->interval->count);
 
        for (uint pos= 0; pos < field->interval->count; pos++)
        {
          char *dst;
          const char *src= field->save_interval->type_names[pos];
          uint hex_length;
          length= field->save_interval->type_lengths[pos];
          hex_length= length * 2;
          field->interval->type_lengths[pos]= hex_length;
          field->interval->type_names[pos]= dst= (char*) sql_alloc(hex_length +
                                                                   1);
          octet2hex(dst, src, length);
        }
      }

      field->interval_id=get_interval_id(&int_count,create_fields,field);
      if (old_int_count != int_count)
      {
	for (const char **pos=field->interval->type_names ; *pos ; pos++)
	  int_length+=(uint) strlen(*pos)+1;	// field + suffix prefix
	int_parts+=field->interval->count+1;
      }
    }
    if (f_maybe_null(field->pack_flag))
      null_fields++;
  }
  int_length+=int_count*2;			// 255 prefix + 0 suffix

	/* Save values in forminfo */

  if (reclength > (ulong) file->max_record_length())
  {
    my_error(ER_TOO_BIG_ROWSIZE, MYF(0), static_cast<long>(file->max_record_length()));
    DBUG_RETURN(1);
  }
  /* Hack to avoid bugs with small static rows in MySQL */
  reclength=max(file->min_record_length(table_options),reclength);
  if (info_length+(ulong) create_fields.elements*FCOMP+288+
      n_length+int_length+com_length+vcol_info_length > 65535L || 
      int_count > 255)
  {
    my_message(ER_TOO_MANY_FIELDS, ER(ER_TOO_MANY_FIELDS), MYF(0));
    DBUG_RETURN(1);
  }

  bzero((char*)forminfo,288);
  length=(info_length+create_fields.elements*FCOMP+288+n_length+int_length+
	  com_length+vcol_info_length);
  int2store(forminfo,length);
  forminfo[256] = (uint8) screens;
  int2store(forminfo+258,create_fields.elements);
  int2store(forminfo+260,info_length);
  int2store(forminfo+262,totlength);
  int2store(forminfo+264,no_empty);
  int2store(forminfo+266,reclength);
  int2store(forminfo+268,n_length);
  int2store(forminfo+270,int_count);
  int2store(forminfo+272,int_parts);
  int2store(forminfo+274,int_length);
  int2store(forminfo+276,time_stamp_pos);
  int2store(forminfo+278,80);			/* Columns needed */
  int2store(forminfo+280,22);			/* Rows needed */
  int2store(forminfo+282,null_fields);
  int2store(forminfo+284,com_length);
  int2store(forminfo+286,vcol_info_length);
  /* forminfo+288 is free to use for additional information */
  DBUG_RETURN(0);
} /* pack_header */


	/* get each unique interval each own id */

static uint get_interval_id(uint *int_count,List<Create_field> &create_fields,
			    Create_field *last_field)
{
  List_iterator<Create_field> it(create_fields);
  Create_field *field;
  TYPELIB *interval=last_field->interval;

  while ((field=it++) != last_field)
  {
    if (field->interval_id && field->interval->count == interval->count)
    {
      const char **a,**b;
      for (a=field->interval->type_names, b=interval->type_names ;
	   *a && !strcmp(*a,*b);
	   a++,b++) ;

      if (! *a)
      {
	return field->interval_id;		// Re-use last interval
      }
    }
  }
  return ++*int_count;				// New unique interval
}


	/* Save fields, fieldnames and intervals */

static bool pack_fields(File file, List<Create_field> &create_fields,
                        ulong data_offset)
{
  reg2 uint i;
  uint int_count, comment_length= 0, vcol_info_length=0;
  uchar buff[MAX_FIELD_WIDTH];
  Create_field *field;
  DBUG_ENTER("pack_fields");

	/* Write field info */

  List_iterator<Create_field> it(create_fields);

  int_count=0;
  while ((field=it++))
  {
    uint recpos;
    uint cur_vcol_expr_len= 0;
    buff[0]= (uchar) field->row;
    buff[1]= (uchar) field->col;
    buff[2]= (uchar) field->sc_length;
    int2store(buff+3, field->length);
    /* The +1 is here becasue the col offset in .frm file have offset 1 */
    recpos= field->offset+1 + (uint) data_offset;
    int3store(buff+5,recpos);
    int2store(buff+8,field->pack_flag);
    DBUG_ASSERT(field->unireg_check < 256);
    buff[10]= (uchar) field->unireg_check;
    buff[12]= (uchar) field->interval_id;
    buff[13]= (uchar) field->sql_type; 
    if (field->sql_type == MYSQL_TYPE_GEOMETRY)
    {
      buff[11]= 0;
      buff[14]= (uchar) field->geom_type;
#ifndef HAVE_SPATIAL
      DBUG_ASSERT(0);                           // Should newer happen
#endif
    }
    else if (field->charset) 
    {
      buff[11]= (uchar) (field->charset->number >> 8);
      buff[14]= (uchar) field->charset->number;
    }
    else
    {
      buff[11]= buff[14]= 0;			// Numerical
    }
    if (field->vcol_info)
    {
      /* 
        Use the interval_id place in the .frm file to store the length of
        the additional data saved for the virtual field
      */
      buff[12]= cur_vcol_expr_len= field->vcol_info->expr_str.length +
	                           FRM_VCOL_HEADER_SIZE(field->interval!=NULL);
      vcol_info_length+= cur_vcol_expr_len + 
	                 FRM_VCOL_HEADER_SIZE(field->interval!=NULL);
      buff[13]= (uchar) MYSQL_TYPE_VIRTUAL;
    }
    int2store(buff+15, field->comment.length);
    comment_length+= field->comment.length;
    set_if_bigger(int_count,field->interval_id);
    if (mysql_file_write(file, buff, FCOMP, MYF_RW))
      DBUG_RETURN(1);
  }

	/* Write fieldnames */
  buff[0]=(uchar) NAMES_SEP_CHAR;
  if (mysql_file_write(file, buff, 1, MYF_RW))
    DBUG_RETURN(1);
  i=0;
  it.rewind();
  while ((field=it++))
  {
    char *pos= strmov((char*) buff,field->field_name);
    * (uchar*) pos++= (uchar) NAMES_SEP_CHAR;
    if (i == create_fields.elements-1)
      *pos++=0;
    if (mysql_file_write(file, buff, (size_t) (pos-(char*) buff), MYF_RW))
      DBUG_RETURN(1);
    i++;
  }

	/* Write intervals */
  if (int_count)
  {
    String tmp((char*) buff,sizeof(buff), &my_charset_bin);
    tmp.length(0);
    it.rewind();
    int_count=0;
    while ((field=it++))
    {
      if (field->interval_id > int_count)
      {
        unsigned char  sep= 0;
        unsigned char  occ[256];
        uint           i;
        unsigned char *val= NULL;

        bzero(occ, sizeof(occ));

        for (i=0; (val= (unsigned char*) field->interval->type_names[i]); i++)
          for (uint j = 0; j < field->interval->type_lengths[i]; j++)
            occ[(unsigned int) (val[j])]= 1;

        if (!occ[(unsigned char)NAMES_SEP_CHAR])
          sep= (unsigned char) NAMES_SEP_CHAR;
        else if (!occ[(unsigned int)','])
          sep= ',';
        else
        {
          for (uint i=1; i<256; i++)
          {
            if(!occ[i])
            {
              sep= i;
              break;
            }
          }

          if(!sep)    /* disaster, enum uses all characters, none left as separator */
          {
            my_message(ER_WRONG_FIELD_TERMINATORS,ER(ER_WRONG_FIELD_TERMINATORS),
                       MYF(0));
            DBUG_RETURN(1);
          }
        }

        int_count= field->interval_id;
        tmp.append(sep);
        for (const char **pos=field->interval->type_names ; *pos ; pos++)
        {
          tmp.append(*pos);
          tmp.append(sep);
        }
        tmp.append('\0');                      // End of intervall
      }
    }
    if (mysql_file_write(file, (uchar*) tmp.ptr(), tmp.length(), MYF_RW))
      DBUG_RETURN(1);
  }
  if (comment_length)
  {
    it.rewind();
    int_count=0;
    while ((field=it++))
    {
      if (field->comment.length)
        if (mysql_file_write(file, (uchar*) field->comment.str,
                             field->comment.length, MYF_RW))
	  DBUG_RETURN(1);
    }
  }
  if (vcol_info_length)
  {
    it.rewind();
    int_count=0;
    while ((field=it++))
    {
      /*
        Pack each virtual field as follows:
        byte 1      = interval_id == 0 ? 1 : 2 
        byte 2      = sql_type
        byte 3      = flags (as of now, 0 - no flags, 1 - field is physically stored)
        [byte 4]    = possible interval_id for sql_type
        next byte ...  = virtual column expression (text data)
      */
      if (field->vcol_info && field->vcol_info->expr_str.length)
      {
        buff[0]= (uchar)(1 + test(field->interval_id));
        buff[1]= (uchar) field->sql_type;
        buff[2]= (uchar) field->stored_in_db;
        if (field->interval_id)
          buff[3]= (uchar) field->interval_id;
      if (my_write(file, buff, 3 + test(field->interval_id), MYF_RW))
          DBUG_RETURN(1);
        if (my_write(file,
                     (uchar*) field->vcol_info->expr_str.str,
                     field->vcol_info->expr_str.length,
                     MYF_RW))
          DBUG_RETURN(1);
      }
    }
  }
  DBUG_RETURN(0);
}


	/* save an empty record on start of formfile */

static bool make_empty_rec(THD *thd, File file,enum legacy_db_type table_type,
			   uint table_options,
			   List<Create_field> &create_fields,
			   uint reclength,
                           ulong data_offset,
                           handler *handler)
{
  int error= 0;
  Field::utype type;
  uint null_count;
  uchar *buff,*null_pos;
  TABLE table;
  TABLE_SHARE share;
  Create_field *field;
  enum_check_fields old_count_cuted_fields= thd->count_cuted_fields;
  DBUG_ENTER("make_empty_rec");

  /* We need a table to generate columns for default values */
  bzero((char*) &table, sizeof(table));
  bzero((char*) &share, sizeof(share));
  table.s= &share;

  if (!(buff=(uchar*) my_malloc((size_t) reclength,MYF(MY_WME | MY_ZEROFILL))))
  {
    DBUG_RETURN(1);
  }

  table.in_use= thd;
  table.s->blob_ptr_size= portable_sizeof_char_ptr;

  null_count=0;
  if (!(table_options & HA_OPTION_PACK_RECORD))
  {
    null_count++;			// Need one bit for delete mark
    *buff|= 1;
  }
  null_pos= buff;

  List_iterator<Create_field> it(create_fields);
  thd->count_cuted_fields= CHECK_FIELD_WARN;    // To find wrong default values
  while ((field=it++))
  {
    /*
      regfield don't have to be deleted as it's allocated with sql_alloc()
    */
    Field *regfield= make_field(&share,
                                buff+field->offset + data_offset,
                                field->length,
                                null_pos + null_count / 8,
                                null_count & 7,
                                field->pack_flag,
                                field->sql_type,
                                field->charset,
                                field->geom_type,
                                field->unireg_check,
                                field->save_interval ? field->save_interval :
                                field->interval, 
                                field->field_name);
    if (!regfield)
    {
      error= 1;
      goto err;                                 // End of memory
    }

    /* save_in_field() will access regfield->table->in_use */
    regfield->init(&table);

    if (!(field->flags & NOT_NULL_FLAG))
    {
      *regfield->null_ptr|= regfield->null_bit;
      null_count++;
    }

    if (field->sql_type == MYSQL_TYPE_BIT && !f_bit_as_char(field->pack_flag))
      null_count+= field->length & 7;

    type= (Field::utype) MTYP_TYPENR(field->unireg_check);

    if (field->def)
    {
      int res= field->def->save_in_field(regfield, 1);
      /* If not ok or warning of level 'note' */
      if (res != 0 && res != 3)
      {
        my_error(ER_INVALID_DEFAULT, MYF(0), regfield->field_name);
        error= 1;
        delete regfield; //To avoid memory leak
        goto err;
      }
    }
    else if (regfield->real_type() == MYSQL_TYPE_ENUM &&
	     (field->flags & NOT_NULL_FLAG))
    {
      regfield->set_notnull();
      regfield->store((longlong) 1, TRUE);
    }
    else if (type == Field::YES)		// Old unireg type
      regfield->store(ER(ER_YES),(uint) strlen(ER(ER_YES)),system_charset_info);
    else if (type == Field::NO)			// Old unireg type
      regfield->store(ER(ER_NO), (uint) strlen(ER(ER_NO)),system_charset_info);
    else
      regfield->reset();
  }
  DBUG_ASSERT(data_offset == ((null_count + 7) / 8));

  /*
    We need to set the unused bits to 1. If the number of bits is a multiple
    of 8 there are no unused bits.
  */
  if (null_count & 7)
    *(null_pos + null_count / 8)|= ~(((uchar) 1 << (null_count & 7)) - 1);

  error= mysql_file_write(file, buff, (size_t) reclength, MYF_RW) != 0;

err:
  my_free(buff);
  thd->count_cuted_fields= old_count_cuted_fields;
  DBUG_RETURN(error);
} /* make_empty_rec */
