mariadb/myisam/mi_rsamepos.c
ingo@mysql.com ec15dda2bf Bug#10932 - Building server with key limit of 128, makes test cases fail
This patch allows to configure MyISAM for 128 indexes per table.
The main problem is the key_map, wich is implemented as an ulonglong.
To get rid of the limit and keep the efficient and flexible
implementation, the highest bit is now used for all upper keys.
This means that the lower keys can be disabled and enabled 
individually as usual and the high keys can only be disabled and
enabled as a block. That way the existing test suite is still
applicable, while more keys work, though slightly less efficient.
To really get more than 64 keys, some defines need to be changed.
Another patch will address this.
2005-07-19 14:13:56 +02:00

56 lines
1.8 KiB
C

/* Copyright (C) 2000 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; 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* read record through position and fix key-position */
/* As mi_rsame but supply a position */
#include "myisamdef.h"
/*
** If inx >= 0 update index pointer
** Returns one of the following values:
** 0 = Ok.
** HA_ERR_KEY_NOT_FOUND = Row is deleted
** HA_ERR_END_OF_FILE = End of file
*/
int mi_rsame_with_pos(MI_INFO *info, byte *record, int inx, my_off_t filepos)
{
DBUG_ENTER("mi_rsame_with_pos");
if (inx < -1 || ! mi_is_key_active(info->s->state.key_map, inx))
{
DBUG_RETURN(my_errno=HA_ERR_WRONG_INDEX);
}
info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
if ((*info->s->read_rnd)(info,record,filepos,0))
{
if (my_errno == HA_ERR_RECORD_DELETED)
my_errno=HA_ERR_KEY_NOT_FOUND;
DBUG_RETURN(my_errno);
}
info->lastpos=filepos;
info->lastinx=inx;
if (inx >= 0)
{
info->lastkey_length=_mi_make_key(info,(uint) inx,info->lastkey,record,
info->lastpos);
info->update|=HA_STATE_KEY_CHANGED; /* Don't use indexposition */
}
DBUG_RETURN(0);
} /* mi_rsame_pos */