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/* Copyright (C) 2006 MySQL AB & MySQL Finland AB & TCX DataKonsult 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
#include "maria_def.h"
#include "ma_rt_index.h"
/*
Read next row with the same key as previous read, but abort if
the key changes.
One may have done a write, update or delete of the previous row.
NOTE! Even if one changes the previous row, the next read is done
based on the position of the last used key!
*/
int maria_rnext_same(MARIA_HA *info, uchar *buf)
{
int error;
uint inx,not_used[2];
MARIA_KEYDEF *keyinfo;
ICP_RESULT icp_res= ICP_MATCH;
DBUG_ENTER("maria_rnext_same");
if ((int) (inx= info->lastinx) < 0 ||
info->cur_row.lastpos == HA_OFFSET_ERROR)
DBUG_RETURN(my_errno=HA_ERR_WRONG_INDEX);
if (fast_ma_readinfo(info))
DBUG_RETURN(my_errno);
keyinfo= info->s->keyinfo+inx;
if (info->s->lock_key_trees)
mysql_rwlock_rdlock(&keyinfo->root_lock);
switch (keyinfo->key_alg) {
#ifdef HAVE_RTREE_KEYS
case HA_KEY_ALG_RTREE:
if ((error=maria_rtree_find_next(info,inx,
maria_read_vec[info->last_key_func])))
{
error=1;
my_errno=HA_ERR_END_OF_FILE;
info->cur_row.lastpos= HA_OFFSET_ERROR;
break;
}
break;
#endif
case HA_KEY_ALG_BTREE:
default:
if (!(info->update & HA_STATE_RNEXT_SAME))
{
/* First rnext_same; Store old key */
memcpy(info->lastkey_buff2, info->last_key.data,
info->last_rkey_length);
}
for (;;)
{
if ((error= _ma_search_next(info, &info->last_key,
SEARCH_BIGGER,
info->s->state.key_root[inx])))
break;
if (ha_key_cmp(keyinfo->seg, info->last_key.data,
info->lastkey_buff2,
info->last_rkey_length, SEARCH_FIND,
not_used))
{
error=1;
my_errno=HA_ERR_END_OF_FILE;
info->cur_row.lastpos= HA_OFFSET_ERROR;
break;
}
/*
If we are at the last key on the key page, allow writers to
access the index.
*/
if (info->int_keypos >= info->int_maxpos &&
ma_yield_and_check_if_killed(info, inx))
{
error= 1;
break;
}
/* Skip rows that are inserted by other threads since we got a lock */
if ((info->s->row_is_visible)(info) &&
((icp_res= ma_check_index_cond(info, inx, buf)) != ICP_NO_MATCH))
break;
}
}
if (info->s->lock_key_trees)
mysql_rwlock_unlock(&keyinfo->root_lock);
/* Don't clear if database-changed */
info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
info->update|= HA_STATE_NEXT_FOUND | HA_STATE_RNEXT_SAME;
if (error || icp_res != ICP_MATCH)
{
fast_ma_writeinfo(info);
if (my_errno == HA_ERR_KEY_NOT_FOUND)
my_errno= HA_ERR_END_OF_FILE;
}
else if (!buf)
{
fast_ma_writeinfo(info);
DBUG_RETURN(info->cur_row.lastpos == HA_OFFSET_ERROR ? my_errno : 0);
}
else if (!(*info->read_record)(info, buf, info->cur_row.lastpos))
{
info->update|= HA_STATE_AKTIV; /* Record is read */
DBUG_RETURN(0);
}
DBUG_RETURN(my_errno);
} /* maria_rnext_same */
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