~drizzle-trunk/drizzle/development

/* Copyright (C) 2000-2002, 2004, 2006 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 */

/*

  remove all records from database

  Identical as hp_create() and hp_open() but used HP_SHARE* instead of name and

  database remains open.

*/

#include "heap_priv.h"

using namespace drizzled;

static void hp_clear_keys(HP_SHARE *info);

void heap_clear(HP_INFO *info)

{

  hp_clear(info->s);

}

void hp_clear(HP_SHARE *info)

{

  hp_clear_dataspace(&info->recordspace);

  hp_clear_keys(info);

  info->records= 0;

  info->blength=1;

  info->changed=0;

  return;

}

/*

  Clear all keys.

  SYNOPSIS

    hp_clear_keys()

    info      A pointer to the heap storage engine HP_SHARE struct.

  DESCRIPTION

    Delete all trees of all indexes and leave them empty.

  RETURN

    void

*/

static void hp_clear_keys(HP_SHARE *info)

{

  uint32_t key;

  for (key=0 ; key < info->keys ; key++)

  {

    HP_KEYDEF *keyinfo = info->keydef + key;

    if (keyinfo->algorithm == HA_KEY_ALG_BTREE)

    {

      delete_tree(&keyinfo->rb_tree);

    }

    else

    {

      HP_BLOCK *block= &keyinfo->block;

      if (block->levels)

        hp_free_level(block,block->levels,block->root,(unsigned char*) 0);

      block->levels=0;

      block->last_allocated=0;

      keyinfo->hash_buckets= 0;

    }

  }

  info->index_length=0;

  return;

}

/*

  Disable all indexes.

  SYNOPSIS

    heap_disable_indexes()

    info      A pointer to the heap storage engine HP_INFO struct.

  DESCRIPTION

    Disable and clear (remove contents of) all indexes.

  RETURN

    0  ok

*/

int heap_disable_indexes(HP_INFO *info)

{

  HP_SHARE *share= info->s;

  if (share->keys)

  {

    hp_clear_keys(share);

    share->currently_disabled_keys= share->keys;

    share->keys= 0;

  }

  return 0;

}

/*

  Enable all indexes

  SYNOPSIS

    heap_enable_indexes()

    info      A pointer to the heap storage engine HP_INFO struct.

  DESCRIPTION

    Enable all indexes. The indexes might have been disabled

    by heap_disable_index() before.

    The function works only if both data and indexes are empty,

    since the heap storage engine cannot repair the indexes.

    To be sure, call handler::delete_all_rows() before.

  RETURN

    0  ok

    HA_ERR_CRASHED data or index is non-empty.

*/

int heap_enable_indexes(HP_INFO *info)

{

  int error= 0;

  HP_SHARE *share= info->s;

  if (share->recordspace.total_data_length || share->index_length)

    error= HA_ERR_CRASHED;

  else

    if (share->currently_disabled_keys)

    {

      share->keys= share->currently_disabled_keys;

      share->currently_disabled_keys= 0;

    }

  return error;

}

/*

  Test if indexes are disabled.

  SYNOPSIS

    heap_indexes_are_disabled()

    info      A pointer to the heap storage engine HP_INFO struct.

  DESCRIPTION

    Test if indexes are disabled.

  RETURN

    0  indexes are not disabled

    1  all indexes are disabled

   [2  non-unique indexes are disabled - NOT YET IMPLEMENTED]

*/

int heap_indexes_are_disabled(HP_INFO *info)

{

  HP_SHARE *share= info->s;

  return (! share->keys && share->currently_disabled_keys);

}