~drizzle-trunk/drizzle/development

/* Copyright (C) 2002-2006 MySQL AB

   This library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Library General Public

   License as published by the Free Software Foundation; version 2

   of the License.

   This library 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

   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public

   License along with this library; if not, write to the Free

   Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,

   MA 02111-1307, USA */

#ifndef _my_handler_h

#define _my_handler_h

#include <mystrings/m_ctype.h>

#include <storage/myisam/myisampack.h>

#ifdef	__cplusplus

extern "C" {

#endif

/*

  There is a hard limit for the maximum number of keys as there are only

  8 bits in the index file header for the number of keys in a table.

  This means that 0..255 keys can exist for a table. The idea of

  HA_MAX_POSSIBLE_KEY is to ensure that one can use myisamchk & tools on

  a MyISAM table for which one has more keys than MyISAM is normally

  compiled for. If you don't have this, you will get a core dump when

  running myisamchk compiled for 128 keys on a table with 255 keys.

*/

#define HA_MAX_POSSIBLE_KEY         255         /* For myisamchk */

/*

  The following defines can be increased if necessary.

  But beware the dependency of MI_MAX_POSSIBLE_KEY_BUFF and HA_MAX_KEY_LENGTH.

*/

#define HA_MAX_KEY_LENGTH           1332        /* Max length in bytes */

#define HA_MAX_KEY_SEG              16          /* Max segments for key */

#define HA_MAX_POSSIBLE_KEY_BUFF    (HA_MAX_KEY_LENGTH + 24+ 6+6)

#define HA_MAX_KEY_BUFF  (HA_MAX_KEY_LENGTH+HA_MAX_KEY_SEG*6+8+8)

typedef struct st_HA_KEYSEG		/* Key-portion */

{

  const CHARSET_INFO *charset;

  uint32_t start;				/* Start of key in record */

  uint32_t null_pos;			/* position to NULL indicator */

  uint16_t bit_pos;                       /* Position to bit part */

  uint16_t flag;

  uint16_t length;			/* Keylength */

  uint8_t  type;				/* Type of key (for sort) */

  uint8_t  language;

  uint8_t  null_bit;			/* bitmask to test for NULL */

  uint8_t  bit_start,bit_end;		/* if bit field */

  uint8_t  bit_length;                    /* Length of bit part */

} HA_KEYSEG;

#define get_key_length(length,key) \

{ if (*(unsigned char*) (key) != 255) \

    length= (uint) *(unsigned char*) ((key)++); \

  else \

  { length= mi_uint2korr((key)+1); (key)+=3; } \

}

#define get_key_length_rdonly(length,key) \

{ if (*(unsigned char*) (key) != 255) \

    length= ((uint) *(unsigned char*) ((key))); \

  else \

  { length= mi_uint2korr((key)+1); } \

}

#define get_key_pack_length(length,length_pack,key) \

{ if (*(unsigned char*) (key) != 255) \

  { length= (uint) *(unsigned char*) ((key)++); length_pack= 1; }\

  else \

  { length=mi_uint2korr((key)+1); (key)+= 3; length_pack= 3; } \

}

#define store_key_length_inc(key,length) \

{ if ((length) < 255) \

  { *(key)++= (length); } \

  else \

  { *(key)=255; mi_int2store((key)+1,(length)); (key)+=3; } \

}

#define size_to_store_key_length(length) ((length) < 255 ? 1 : 3)

#define get_rec_bits(bit_ptr, bit_ofs, bit_len) \

  (((((uint16_t) (bit_ptr)[1] << 8) | (uint16_t) (bit_ptr)[0]) >> (bit_ofs)) & \

   ((1 << (bit_len)) - 1))

#define set_rec_bits(bits, bit_ptr, bit_ofs, bit_len) \

{ \

  (bit_ptr)[0]= ((bit_ptr)[0] & ~(((1 << (bit_len)) - 1) << (bit_ofs))) | \

                ((bits) << (bit_ofs)); \

  if ((bit_ofs) + (bit_len) > 8) \

    (bit_ptr)[1]= ((bit_ptr)[1] & ~((1 << ((bit_len) - 8 + (bit_ofs))) - 1)) | \

                  ((bits) >> (8 - (bit_ofs))); \

}

#define clr_rec_bits(bit_ptr, bit_ofs, bit_len) \

  set_rec_bits(0, bit_ptr, bit_ofs, bit_len)

extern int ha_compare_text(const CHARSET_INFO * const, unsigned char *, uint, unsigned char *, uint, bool, bool);

extern HA_KEYSEG *ha_find_null(HA_KEYSEG *keyseg, unsigned char *a);

void my_handler_error_register(void);

void my_handler_error_unregister(void);

extern int ha_key_cmp(HA_KEYSEG *keyseg, unsigned char *a,unsigned char *b,

                      uint32_t key_length,uint32_t nextflag,uint32_t *diff_length);

/*

  Inside an in-memory data record, memory pointers to pieces of the

  record (like BLOBs) are stored in their native byte order and in

  this amount of bytes.

*/

#define portable_sizeof_char_ptr 8

#ifdef	__cplusplus

}

#endif

#endif /* _my_handler_h */