mirror of
https://github.com/MariaDB/server.git
synced 2025-10-31 02:46:29 +01:00
68 lines
2.2 KiB
C
68 lines
2.2 KiB
C
/* Copyright (c) 2000-2002, 2004-2007 MySQL AB
|
|
Use is subject to license terms
|
|
|
|
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 "heapdef.h"
|
|
|
|
/* Read first record with the current key */
|
|
|
|
int heap_rfirst(HP_INFO *info, uchar *record, int inx)
|
|
{
|
|
HP_SHARE *share = info->s;
|
|
HP_KEYDEF *keyinfo = share->keydef + inx;
|
|
|
|
DBUG_ENTER("heap_rfirst");
|
|
info->lastinx= inx;
|
|
info->key_version= info->s->key_version;
|
|
|
|
if (keyinfo->algorithm == HA_KEY_ALG_BTREE)
|
|
{
|
|
uchar *pos;
|
|
|
|
if ((pos = tree_search_edge(&keyinfo->rb_tree, info->parents,
|
|
&info->last_pos, offsetof(TREE_ELEMENT, left))))
|
|
{
|
|
memcpy(&pos, pos + (*keyinfo->get_key_length)(keyinfo, pos),
|
|
sizeof(uchar*));
|
|
info->current_ptr = pos;
|
|
memcpy(record, pos, (size_t)share->reclength);
|
|
/*
|
|
If we're performing index_first on a table that was taken from
|
|
table cache, info->lastkey_len is initialized to previous query.
|
|
Thus we set info->lastkey_len to proper value for subsequent
|
|
heap_rnext() calls.
|
|
This is needed for DELETE queries only, otherwise this variable is
|
|
not used.
|
|
Note that the same workaround may be needed for heap_rlast(), but
|
|
for now heap_rlast() is never used for DELETE queries.
|
|
*/
|
|
info->lastkey_len= 0;
|
|
info->update = HA_STATE_AKTIV;
|
|
}
|
|
else
|
|
{
|
|
info->update= HA_STATE_NO_KEY;
|
|
my_errno = HA_ERR_END_OF_FILE;
|
|
DBUG_RETURN(my_errno);
|
|
}
|
|
DBUG_RETURN(0);
|
|
}
|
|
else
|
|
{
|
|
/* We can't scan a non existing key value with hash index */
|
|
my_errno= HA_ERR_WRONG_COMMAND;
|
|
DBUG_RETURN(my_errno);
|
|
}
|
|
}
|