1/* Copyright (c) 2000-2002, 2004-2007 MySQL AB
2 Use is subject to license terms
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; version 2 of the License.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with this program; if not, write to the Free Software
15 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */
16
17/* Read a record with random-access. The position to the record must
18 get by MI_INFO. The next record can be read with pos= MI_POS_ERROR */
19
20
21#include "myisamdef.h"
22
23/*
24 Read a row based on position.
25 If filepos= HA_OFFSET_ERROR then read next row
26 Return values
27 Returns one of following values:
28 0 = Ok.
29 HA_ERR_RECORD_DELETED = Record is deleted.
30 HA_ERR_END_OF_FILE = EOF.
31*/
32
33int mi_rrnd(MI_INFO *info, uchar *buf, register my_off_t filepos)
34{
35 my_bool skip_deleted_blocks;
36 DBUG_ENTER("mi_rrnd");
37
38 skip_deleted_blocks=0;
39
40 if (filepos == HA_OFFSET_ERROR)
41 {
42 skip_deleted_blocks=1;
43 if (info->lastpos == HA_OFFSET_ERROR) /* First read ? */
44 filepos= info->s->pack.header_length; /* Read first record */
45 else
46 filepos= info->nextpos;
47 }
48
49 if (info->once_flags & RRND_PRESERVE_LASTINX)
50 info->once_flags&= ~RRND_PRESERVE_LASTINX;
51 else
52 info->lastinx= -1; /* Can't forward or backward */
53 /* Init all but update-flag */
54 info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
55
56 if (info->opt_flag & WRITE_CACHE_USED && flush_io_cache(&info->rec_cache))
57 DBUG_RETURN(my_errno);
58
59 DBUG_RETURN ((*info->s->read_rnd)(info,buf,filepos,skip_deleted_blocks));
60}
61