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
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/* Copyright (C) 2000-2004 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 "myisamdef.h"
#include "rt_index.h"
/*
Read next row with the same key as previous read
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 mi_rnext(MI_INFO *info, uchar *buf, int inx)
{
int error,changed;
uint flag;
int res= 0;
DBUG_ENTER("mi_rnext");
if ((inx = _mi_check_index(info,inx)) < 0)
DBUG_RETURN(my_errno);
flag=SEARCH_BIGGER; /* Read next */
if (info->lastpos == HA_OFFSET_ERROR && info->update & HA_STATE_PREV_FOUND)
flag=0; /* Read first */
if (fast_mi_readinfo(info))
DBUG_RETURN(my_errno);
if (info->s->concurrent_insert)
rw_rdlock(&info->s->key_root_lock[inx]);
changed=_mi_test_if_changed(info);
if (!flag)
{
switch(info->s->keyinfo[inx].key_alg){
#ifdef HAVE_RTREE_KEYS
case HA_KEY_ALG_RTREE:
error=rtree_get_first(info,inx,info->lastkey_length);
break;
#endif
case HA_KEY_ALG_BTREE:
default:
error=_mi_search_first(info,info->s->keyinfo+inx,
info->s->state.key_root[inx]);
break;
}
}
else
{
switch (info->s->keyinfo[inx].key_alg) {
#ifdef HAVE_RTREE_KEYS
case HA_KEY_ALG_RTREE:
/*
Note that rtree doesn't support that the table
may be changed since last call, so we do need
to skip rows inserted by other threads like in btree
*/
error= rtree_get_next(info,inx,info->lastkey_length);
break;
#endif
case HA_KEY_ALG_BTREE:
default:
if (!changed)
error= _mi_search_next(info,info->s->keyinfo+inx,info->lastkey,
info->lastkey_length,flag,
info->s->state.key_root[inx]);
else
error= _mi_search(info,info->s->keyinfo+inx,info->lastkey,
USE_WHOLE_KEY,flag, info->s->state.key_root[inx]);
}
}
if (!error)
{
while ((info->s->concurrent_insert &&
info->lastpos >= info->state->data_file_length) ||
(info->index_cond_func &&
!(res= mi_check_index_cond(info, inx, buf))))
{
/* Skip rows inserted by other threads since we got a lock */
if ((error=_mi_search_next(info,info->s->keyinfo+inx,
info->lastkey,
info->lastkey_length,
SEARCH_BIGGER,
info->s->state.key_root[inx])))
break;
}
if (!error && res == 2)
{
if (info->s->concurrent_insert)
rw_unlock(&info->s->key_root_lock[inx]);
info->lastpos= HA_OFFSET_ERROR;
DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
}
}
if (info->s->concurrent_insert)
rw_unlock(&info->s->key_root_lock[inx]);
/* Don't clear if database-changed */
info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
info->update|= HA_STATE_NEXT_FOUND;
if (error)
{
if (my_errno == HA_ERR_KEY_NOT_FOUND)
my_errno=HA_ERR_END_OF_FILE;
}
else if (!buf)
{
DBUG_RETURN(info->lastpos==HA_OFFSET_ERROR ? my_errno : 0);
}
else if (!(*info->read_record)(info,info->lastpos,buf))
{
info->update|= HA_STATE_AKTIV; /* Record is read */
DBUG_RETURN(0);
}
DBUG_PRINT("error",("Got error: %d, errno: %d",error, my_errno));
DBUG_RETURN(my_errno);
} /* mi_rnext */
|