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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
/* Copyright (C) 2006 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; 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 "maria_def.h"
#include "ma_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 maria_rnext(MARIA_HA *info, uchar *buf, int inx)
{
int error,changed;
uint flag;
MARIA_SHARE *share= info->s;
MARIA_KEYDEF *keyinfo;
check_result_t check= CHECK_POS;
uint update_mask= HA_STATE_NEXT_FOUND;
DBUG_ENTER("maria_rnext");
if ((inx = _ma_check_index(info,inx)) < 0)
DBUG_RETURN(my_errno);
flag=SEARCH_BIGGER; /* Read next */
if (info->cur_row.lastpos == HA_OFFSET_ERROR &&
info->update & HA_STATE_PREV_FOUND)
flag=0; /* Read first */
if (fast_ma_readinfo(info))
DBUG_RETURN(my_errno);
keyinfo= share->keyinfo + inx;
if (share->lock_key_trees)
mysql_rwlock_rdlock(&keyinfo->root_lock);
changed= _ma_test_if_changed(info);
if (!flag)
{
switch (keyinfo->key_alg){
#ifdef HAVE_RTREE_KEYS
case HA_KEY_ALG_RTREE:
error=maria_rtree_get_first(info, inx,
info->last_key.data_length +
info->last_key.ref_length);
break;
#endif
case HA_KEY_ALG_BTREE:
default:
error= _ma_search_first(info, keyinfo, share->state.key_root[inx]);
break;
}
/*
"search first" failed. This means we have no pivot for
"search next", or in other words MI_INFO::lastkey is
likely uninitialized.
Normally SQL layer would never request "search next" if
"search first" failed. But HANDLER may do anything.
As mi_rnext() without preceding mi_rkey()/mi_rfirst()
equals to mi_rfirst(), we must restore original state
as if failing mi_rfirst() was not called.
*/
if (error)
update_mask|= HA_STATE_PREV_FOUND;
}
else
{
switch (keyinfo->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= maria_rtree_get_next(info, inx, info->last_key.data_length +
info->last_key.ref_length);
break;
#endif
case HA_KEY_ALG_BTREE:
default:
if (!changed)
error= _ma_search_next(info, &info->last_key,
flag | info->last_key.flag,
share->state.key_root[inx]);
else
error= _ma_search(info, &info->last_key, flag | info->last_key.flag,
share->state.key_root[inx]);
}
}
if (!error)
{
while (!(*share->row_is_visible)(info) ||
((check= ma_check_index_cond(info, inx, buf)) == CHECK_NEG))
{
/*
If we are at the last key on the key page, allow writers to
access the index.
*/
if (info->int_keypos >= info->int_maxpos &&
ma_yield_and_check_if_killed(info, inx))
{
/* my_errno is set by ma_yield_and_check_if_killed() */
error= 1;
break;
}
/* Skip rows inserted by other threads since we got a lock */
if ((error= _ma_search_next(info, &info->last_key,
SEARCH_BIGGER,
share->state.key_root[inx])))
break;
}
}
if (share->lock_key_trees)
mysql_rwlock_unlock(&keyinfo->root_lock);
/* Don't clear if database-changed */
info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
info->update|= update_mask;
if (error || check != CHECK_POS)
{
fast_ma_writeinfo(info);
if (my_errno == HA_ERR_KEY_NOT_FOUND)
my_errno= HA_ERR_END_OF_FILE;
}
else if (!buf)
{
fast_ma_writeinfo(info);
DBUG_RETURN(info->cur_row.lastpos == HA_OFFSET_ERROR ? my_errno : 0);
}
else if (!(*info->read_record)(info, buf, info->cur_row.lastpos))
{
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);
} /* maria_rnext */
|
