~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems, Inc.

 *

 *  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; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  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

 */

#pragma once

#include <drizzled/base.h>

#include <drizzled/definitions.h>

#include <drizzled/lex_string.h>

#include <drizzled/thr_lock.h>

namespace drizzled {

class KeyPartInfo 

{	/* Info about a key part */

public:

  Field *field;

  unsigned int	offset;				/* offset in record (from 0) */

  unsigned int	null_offset;			/* Offset to null_bit in record */

  /* Length of key part in bytes, excluding NULL flag and length bytes */

  uint16_t length;

  /*

    Number of bytes required to store the keypart value. This may be

    different from the "length" field as it also counts

     - possible NULL-flag byte (see HA_KEY_NULL_LENGTH) [if null_bit != 0,

       the first byte stored at offset is 1 if null, 0 if non-null; the

       actual value is stored from offset+1].

     - possible HA_KEY_BLOB_LENGTH bytes needed to store actual value length.

  */

  uint16_t store_length;

  uint16_t key_type;

private:

public:

  uint16_t getKeyType() const

  {

    return key_type;

  }

  uint16_t fieldnr;			/* Fieldnum in UNIREG (1,2,3,...) */

  uint16_t key_part_flag;			/* 0 or HA_REVERSE_SORT */

  uint8_t type;

  uint8_t null_bit;			/* Position to null_bit */

};

class KeyInfo 

{

public:

  unsigned int	key_length;		/* Tot length of key */

  enum  ha_key_alg algorithm;

  unsigned long flags;			/* dupp key and pack flags */

  unsigned int key_parts;		/* How many key_parts */

  uint32_t  extra_length;

  unsigned int usable_key_parts;	/* Should normally be = key_parts */

  uint32_t  block_size;

  KeyPartInfo *key_part;

  const char* name;				/* Name of key */

  /*

    Array of AVG(#records with the same field value) for 1st ... Nth key part.

    0 means 'not known'.

    For temporary heap tables this member is NULL.

  */

  ulong *rec_per_key;

  Table *table;

  str_ref comment;

};

class RegInfo 

{

public:		/* Extra info about reg */

  JoinTable *join_tab;	/* Used by SELECT() */

  enum thr_lock_type lock_type;		/* How database is used */

  bool not_exists_optimize;

  bool impossible_range;

  RegInfo()

    : join_tab(NULL), lock_type(TL_UNLOCK),

      not_exists_optimize(false), impossible_range(false) {}

  void reset()

  {

    join_tab= NULL;

    lock_type= TL_UNLOCK;

    not_exists_optimize= false;

    impossible_range= false;

  }

};

typedef int *(*update_var)(Session *, struct drizzle_show_var *);

} /* namespace drizzled */

	/* Bits in form->status */

#define STATUS_NO_RECORD	(1+2)	/* Record isn't usably */

#define STATUS_GARBAGE		1

#define STATUS_NOT_FOUND	2	/* No record in database when needed */

#define STATUS_NO_PARENT	4	/* Parent record wasn't found */

#define STATUS_NULL_ROW		32	/* table->null_row is set */