~drizzle-trunk/drizzle/development

/* Copyright (C) 2000-2006 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 */

/* Update an old row in a MyISAM table */

#include "myisamdef.h"

int mi_update(register MI_INFO *info, const uchar *oldrec, uchar *newrec)

{

  int flag,key_changed,save_errno;

  register my_off_t pos;

  uint i;

  uchar old_key[MI_MAX_KEY_BUFF],*new_key;

  bool auto_key_changed=0;

  uint64_t changed;

  MYISAM_SHARE *share= info->s;

  ha_checksum old_checksum= 0;

  if (!(info->update & HA_STATE_AKTIV))

  {

    return(my_errno=HA_ERR_KEY_NOT_FOUND);

  }

  if (share->options & HA_OPTION_READ_ONLY_DATA)

  {

    return(my_errno=EACCES);

  }

  if (info->state->key_file_length >= share->base.margin_key_file_length)

  {

    return(my_errno=HA_ERR_INDEX_FILE_FULL);

  }

  pos=info->lastpos;

  if (_mi_readinfo(info,F_WRLCK,1))

    return(my_errno);

  if (share->calc_checksum)

    old_checksum=info->checksum=(*share->calc_checksum)(info,oldrec);

  if ((*share->compare_record)(info,oldrec))

  {

    save_errno=my_errno;

    goto err_end;			/* Record has changed */

  }

  /* Calculate and check all unique constraints */

  key_changed=0;

  for (i=0 ; i < share->state.header.uniques ; i++)

  {

    MI_UNIQUEDEF *def=share->uniqueinfo+i;

    if (mi_unique_comp(def, newrec, oldrec,1) &&

	mi_check_unique(info, def, newrec, mi_unique_hash(def, newrec),

			info->lastpos))

    {

      save_errno=my_errno;

      goto err_end;

    }

  }

  if (_mi_mark_file_changed(info))

  {

    save_errno=my_errno;

    goto err_end;

  }

  /* Check which keys changed from the original row */

  new_key=info->lastkey2;

  changed=0;

  for (i=0 ; i < share->base.keys ; i++)

  {

    if (mi_is_key_active(share->state.key_map, i))

    {

      {

	uint new_length=_mi_make_key(info,i,new_key,newrec,pos);

	uint old_length=_mi_make_key(info,i,old_key,oldrec,pos);

        /* The above changed info->lastkey2. Inform mi_rnext_same(). */

        info->update&= ~HA_STATE_RNEXT_SAME;

	if (new_length != old_length ||

	    memcmp(old_key,new_key,new_length))

	{

	  if ((int) i == info->lastinx)

	    key_changed|=HA_STATE_WRITTEN;	/* Mark that keyfile changed */

	  changed|=((uint64_t) 1 << i);

	  share->keyinfo[i].version++;

	  if (share->keyinfo[i].ck_delete(info,i,old_key,old_length)) goto err;

	  if (share->keyinfo[i].ck_insert(info,i,new_key,new_length)) goto err;

	  if (share->base.auto_key == i+1)

	    auto_key_changed=1;

	}

      }

    }

  }

  /*

    If we are running with external locking, we must update the index file

    that something has changed.

  */

  if (changed)

    key_changed|= HA_STATE_CHANGED;

  if (share->calc_checksum)

  {

    info->checksum=(*share->calc_checksum)(info,newrec);

    /* Store new checksum in index file header */

    key_changed|= HA_STATE_CHANGED;

  }

  {

    /*

      Don't update index file if data file is not extended and no status

      information changed

    */

    MI_STATUS_INFO state;

    ha_rows org_split;

    my_off_t org_delete_link;

    memcpy(&state, info->state, sizeof(state));

    org_split=	     share->state.split;

    org_delete_link= share->state.dellink;

    if ((*share->update_record)(info,pos,newrec))

      goto err;

    if (!key_changed &&

	(memcmp(&state, info->state, sizeof(state)) ||

	 org_split != share->state.split ||

	 org_delete_link != share->state.dellink))

      key_changed|= HA_STATE_CHANGED;		/* Must update index file */

  }

  if (auto_key_changed)

    set_if_bigger(info->s->state.auto_increment,

                  retrieve_auto_increment(info, newrec));

  if (share->calc_checksum)

    info->state->checksum+=(info->checksum - old_checksum);

  info->update= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED | HA_STATE_AKTIV |

		 key_changed);

  /*

    Every myisam function that updates myisam table must end with

    call to _mi_writeinfo(). If operation (second param of

    _mi_writeinfo()) is not 0 it sets share->changed to 1, that is

    flags that data has changed. If operation is 0, this function

    equals to no-op in this case.

    mi_update() must always pass !0 value as operation, since even if

    there is no index change there could be data change.

  */

  VOID(_mi_writeinfo(info, WRITEINFO_UPDATE_KEYFILE));

  if (info->invalidator != 0)

  {

    (*info->invalidator)(info->filename);

    info->invalidator=0;

  }

  return(0);

err:

  save_errno=my_errno;

  if (changed)

    key_changed|= HA_STATE_CHANGED;

  if (my_errno == HA_ERR_FOUND_DUPP_KEY || my_errno == HA_ERR_OUT_OF_MEM ||

      my_errno == HA_ERR_RECORD_FILE_FULL)

  {

    info->errkey= (int) i;

    flag=0;

    do

    {

      if (((uint64_t) 1 << i) & changed)

      {

	{

	  uint new_length=_mi_make_key(info,i,new_key,newrec,pos);

	  uint old_length= _mi_make_key(info,i,old_key,oldrec,pos);

	  if ((flag++ && _mi_ck_delete(info,i,new_key,new_length)) ||

	      _mi_ck_write(info,i,old_key,old_length))

	    break;

	}

      }

    } while (i-- != 0);

  }

  else

  {

    mi_print_error(info->s, HA_ERR_CRASHED);

    mi_mark_crashed(info);

  }

  info->update= (HA_STATE_CHANGED | HA_STATE_AKTIV | HA_STATE_ROW_CHANGED |

		 key_changed);

 err_end:

  VOID(_mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE));

  if (save_errno == HA_ERR_KEY_NOT_FOUND)

  {

    mi_print_error(info->s, HA_ERR_CRASHED);

    save_errno=HA_ERR_CRASHED;

  }

  return(my_errno=save_errno);

} /* mi_update */