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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
/* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
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 St, Fifth Floor, Boston, MA 02110-1335 USA */
#include "mariadb.h"
#include "datadict.h"
#include "sql_priv.h"
#include "sql_class.h"
#include "sql_table.h"
#include "ha_sequence.h"
static int read_string(File file, uchar**to, size_t length)
{
DBUG_ENTER("read_string");
/* This can't use MY_THREAD_SPECIFIC as it's used on server start */
if (!(*to= (uchar*) my_malloc(length+1,MYF(MY_WME))) ||
mysql_file_read(file, *to, length, MYF(MY_NABP)))
{
my_free(*to);
*to= 0;
DBUG_RETURN(1);
}
*((char*) *to+length)= '\0'; // C-style safety
DBUG_RETURN (0);
}
/**
Check type of .frm if we are not going to parse it.
@param[in] thd The current session.
@param[in] path path to FRM file.
@param[in/out] engine_name table engine name (length < NAME_CHAR_LEN)
engine_name is a LEX_CSTRING, where engine_name->str must point to
a buffer of at least NAME_CHAR_LEN+1 bytes.
If engine_name is 0, then the function will only test if the file is a
view or not
@param[out] is_sequence 1 if table is a SEQUENCE, 0 otherwise
@retval TABLE_TYPE_UNKNOWN error - file can't be opened
@retval TABLE_TYPE_NORMAL table
@retval TABLE_TYPE_SEQUENCE sequence table
@retval TABLE_TYPE_VIEW view
*/
Table_type dd_frm_type(THD *thd, char *path, LEX_CSTRING *engine_name,
bool *is_sequence)
{
File file;
uchar header[40]; //"TYPE=VIEW\n" it is 10 characters
size_t error;
Table_type type= TABLE_TYPE_UNKNOWN;
uchar dbt;
DBUG_ENTER("dd_frm_type");
*is_sequence= 0;
if ((file= mysql_file_open(key_file_frm, path, O_RDONLY | O_SHARE, MYF(0)))
< 0)
DBUG_RETURN(TABLE_TYPE_UNKNOWN);
/*
We return TABLE_TYPE_NORMAL if we can open the .frm file. This allows us
to drop a bad .frm file with DROP TABLE
*/
type= TABLE_TYPE_NORMAL;
/*
Initialize engine name in case we are not able to find it out
The cast is safe, as engine_name->str points to a usable buffer.
*/
if (engine_name)
{
engine_name->length= 0;
((char*) (engine_name->str))[0]= 0;
}
if (unlikely((error= mysql_file_read(file, (uchar*) header, sizeof(header), MYF(MY_NABP)))))
goto err;
if (unlikely((!strncmp((char*) header, "TYPE=VIEW\n", 10))))
{
type= TABLE_TYPE_VIEW;
goto err;
}
/* engine_name is 0 if we only want to know if table is view or not */
if (!engine_name)
goto err;
if (!is_binary_frm_header(header))
goto err;
dbt= header[3];
if (((header[39] >> 4) & 3) == HA_CHOICE_YES)
{
DBUG_PRINT("info", ("Sequence found"));
*is_sequence= 1;
}
/* cannot use ha_resolve_by_legacy_type without a THD */
if (thd && dbt < DB_TYPE_FIRST_DYNAMIC)
{
handlerton *ht= ha_resolve_by_legacy_type(thd, (enum legacy_db_type)dbt);
if (ht)
{
*engine_name= hton2plugin[ht->slot]->name;
goto err;
}
}
/* read the true engine name */
{
MY_STAT state;
uchar *frm_image= 0;
uint n_length;
if (mysql_file_fstat(file, &state, MYF(MY_WME)))
goto err;
if (mysql_file_seek(file, 0, SEEK_SET, MYF(MY_WME)))
goto err;
if (read_string(file, &frm_image, (size_t)state.st_size))
goto err;
if ((n_length= uint4korr(frm_image+55)))
{
uint record_offset= uint2korr(frm_image+6)+
((uint2korr(frm_image+14) == 0xffff ?
uint4korr(frm_image+47) : uint2korr(frm_image+14)));
uint reclength= uint2korr(frm_image+16);
uchar *next_chunk= frm_image + record_offset + reclength;
uchar *buff_end= next_chunk + n_length;
uint connect_string_length= uint2korr(next_chunk);
next_chunk+= connect_string_length + 2;
if (next_chunk + 2 < buff_end)
{
uint len= uint2korr(next_chunk);
if (len <= NAME_CHAR_LEN)
{
/*
The following cast is safe as the caller has allocated buffer
and it's up to this function to generate the name.
*/
strmake((char*) engine_name->str, (char*)next_chunk + 2,
engine_name->length= len);
}
}
}
my_free(frm_image);
}
/* Probably a table. */
err:
mysql_file_close(file, MYF(MY_WME));
DBUG_RETURN(type);
}
/*
Regenerate a metadata locked table.
@param thd Thread context.
@param db Name of the database to which the table belongs to.
@param name Table name.
@retval FALSE Success.
@retval TRUE Error.
*/
bool dd_recreate_table(THD *thd, const char *db, const char *table_name)
{
HA_CREATE_INFO create_info;
char path_buf[FN_REFLEN + 1];
DBUG_ENTER("dd_recreate_table");
/* There should be a exclusive metadata lock on the table. */
DBUG_ASSERT(thd->mdl_context.is_lock_owner(MDL_key::TABLE, db, table_name,
MDL_EXCLUSIVE));
create_info.init();
build_table_filename(path_buf, sizeof(path_buf) - 1,
db, table_name, "", 0);
/* Attempt to reconstruct the table. */
DBUG_RETURN(ha_create_table(thd, path_buf, db, table_name, &create_info, 0));
}
|
