1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
/* Copyright (C) 2000-2003 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 */
#include "myrg_def.h"
/*
Read previous row with the same key as previous read
*/
int myrg_rprev(MYRG_INFO *info, byte *buf, int inx)
{
int err;
MI_INFO *mi;
if (!info->current_table)
return (HA_ERR_KEY_NOT_FOUND);
/* at first, do rprev for the table found before */
if ((err=mi_rprev(info->current_table->table,NULL,inx)))
{
if (err == HA_ERR_END_OF_FILE)
{
queue_remove(&(info->by_key),0);
if (!info->by_key.elements)
return HA_ERR_END_OF_FILE;
}
else
return err;
}
else
{
/* Found here, adding to queue */
queue_top(&(info->by_key))=(byte *)(info->current_table);
queue_replaced(&(info->by_key));
}
/* now, mymerge's read_prev is as simple as one queue_top */
mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table;
return _myrg_mi_read_record(mi,buf);
}
|
