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
|
/* Copyright (c) 2003, 2025, Oracle and/or its affiliates.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, version 2.0,
as published by the Free Software Foundation.
This program is designed to work with certain software (including
but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation. The authors of MySQL hereby grant you an additional
permission to link the program and your derivative works with the
separately licensed software that they have either included with
the program or referenced in the documentation.
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, version 2.0, 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 St, Fifth Floor, Boston, MA 02110-1301 USA */
/*
Preload indexes into key cache
*/
#include <errno.h>
#include <stddef.h>
#include <sys/types.h>
#include <algorithm>
#include "my_dbug.h"
#include "my_inttypes.h"
#include "my_macros.h"
#include "storage/myisam/myisamdef.h"
/*
Preload pages of the index file for a table into the key cache
SYNOPSIS
mi_preload()
info open table
map map of indexes to preload into key cache
ignore_leaves only non-leaves pages are to be preloaded
RETURN VALUE
0 if a success. error code - otherwise.
NOTES.
At present pages for all indexes are preloaded.
In future only pages for indexes specified in the key_map parameter
of the table will be preloaded.
*/
int mi_preload(MI_INFO *info, ulonglong key_map, bool ignore_leaves) {
uint i;
ulong length, block_length = 0;
uchar *buff = nullptr;
MYISAM_SHARE *share = info->s;
uint keys = share->state.header.keys;
MI_KEYDEF *keyinfo = share->keyinfo;
my_off_t key_file_length = share->state.state.key_file_length;
my_off_t pos = share->base.keystart;
DBUG_TRACE;
if (!keys || !mi_is_any_key_active(key_map) || key_file_length == pos)
return 0;
/* Preload into a non initialized key cache should never happen. */
assert(share->key_cache->key_cache_inited);
block_length = keyinfo[0].block_length;
if (ignore_leaves) {
/* Check whether all indexes use the same block size */
for (i = 1; i < keys; i++) {
if (keyinfo[i].block_length != block_length) {
set_my_errno(HA_ERR_NON_UNIQUE_BLOCK_SIZE);
return HA_ERR_NON_UNIQUE_BLOCK_SIZE;
}
}
} else
block_length = share->key_cache->key_cache_block_size;
length = info->preload_buff_size / block_length * block_length;
length = std::max(length, block_length);
if (!(buff = (uchar *)my_malloc(mi_key_memory_preload_buffer, length,
MYF(MY_WME)))) {
set_my_errno(HA_ERR_OUT_OF_MEM);
return HA_ERR_OUT_OF_MEM;
}
if (flush_key_blocks(share->key_cache, keycache_thread_var(), share->kfile,
FLUSH_RELEASE))
goto err;
do {
/* Read the next block of index file into the preload buffer */
if ((my_off_t)length > (key_file_length - pos))
length = (ulong)(key_file_length - pos);
if (mysql_file_pread(share->kfile, (uchar *)buff, length, pos,
MYF(MY_FAE | MY_FNABP)))
goto err;
if (ignore_leaves) {
uchar *end = buff + length;
do {
if (mi_test_if_nod(buff)) {
if (key_cache_insert(share->key_cache, keycache_thread_var(),
share->kfile, pos, DFLT_INIT_HITS, (uchar *)buff,
block_length))
goto err;
}
pos += block_length;
} while ((buff += block_length) != end);
buff = end - length;
} else {
if (key_cache_insert(share->key_cache, keycache_thread_var(),
share->kfile, pos, DFLT_INIT_HITS, (uchar *)buff,
length))
goto err;
pos += length;
}
} while (pos != key_file_length);
my_free(buff);
return 0;
err:
my_free(buff);
set_my_errno(errno);
return errno;
}
|
