1/* Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
2
3 This program is free software; you can redistribute it and/or modify
4 it under the terms of the GNU General Public License as published by
5 the Free Software Foundation; version 2 of the License.
6
7 This program is distributed in the hope that it will be useful,
8 but WITHOUT ANY WARRANTY; without even the implied warranty of
9 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 GNU General Public License for more details.
11
12 You should have received a copy of the GNU General Public License
13 along with this program; if not, write to the Free Software
14 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
15
16
17/**
18 @file
19
20 @brief
21 Functions for discover of frm file from handler
22*/
23
24#include "mariadb.h"
25#include "sql_priv.h"
26#include "unireg.h"
27#include "discover.h"
28#include <my_dir.h>
29
30/**
31 Read the contents of a .frm file.
32
33 frmdata and len are set to 0 on error.
34
35 @param name path to table-file "db/name"
36 @param frmdata frm data
37 @param len length of the read frmdata
38
39 @retval
40 0 ok
41 @retval
42 1 Could not open file
43 @retval
44 2 Could not stat file
45 @retval
46 3 Could not allocate data for read. Could not read file
47*/
48
49int readfrm(const char *name, const uchar **frmdata, size_t *len)
50{
51 int error;
52 char index_file[FN_REFLEN];
53 File file;
54 size_t read_len;
55 uchar *read_data;
56 MY_STAT state;
57 DBUG_ENTER("readfrm");
58 DBUG_PRINT("enter",("name: '%s'",name));
59
60 *frmdata= NULL; // In case of errors
61 *len= 0;
62 error= 1;
63 if ((file= mysql_file_open(key_file_frm,
64 fn_format(index_file, name, "", reg_ext,
65 MY_UNPACK_FILENAME|MY_APPEND_EXT),
66 O_RDONLY | O_SHARE,
67 MYF(0))) < 0)
68 goto err_end;
69
70 // Get length of file
71 error= 2;
72 if (mysql_file_fstat(file, &state, MYF(0)))
73 goto err;
74 read_len= (size_t)MY_MIN(FRM_MAX_SIZE, state.st_size); // safety
75
76 // Read whole frm file
77 error= 3;
78 if (!(read_data= (uchar*)my_malloc(read_len, MYF(MY_WME))))
79 goto err;
80 if (mysql_file_read(file, read_data, read_len, MYF(MY_NABP)))
81 {
82 my_free(read_data);
83 goto err;
84 }
85
86 // Setup return data
87 *frmdata= (uchar*) read_data;
88 *len= read_len;
89 error= 0;
90
91 err:
92 (void) mysql_file_close(file, MYF(MY_WME));
93
94 err_end: /* Here when no file */
95 DBUG_RETURN (error);
96} /* readfrm */
97
98
99/*
100 Write the content of a frm data pointer
101 to a frm file.
102
103 @param path path to table-file "db/name"
104 @param frmdata frm data
105 @param len length of the frmdata
106
107 @retval
108 0 ok
109 @retval
110 2 Could not write file
111*/
112
113int writefrm(const char *path, const char *db, const char *table,
114 bool tmp_table, const uchar *frmdata, size_t len)
115{
116 char file_name[FN_REFLEN+1];
117 int error;
118 int create_flags= O_RDWR | O_TRUNC;
119 DBUG_ENTER("writefrm");
120 DBUG_PRINT("enter",("name: '%s' len: %lu ",path, (ulong) len));
121
122 if (tmp_table)
123 create_flags|= O_EXCL | O_NOFOLLOW;
124
125 strxnmov(file_name, sizeof(file_name)-1, path, reg_ext, NullS);
126
127 File file= mysql_file_create(key_file_frm, file_name,
128 CREATE_MODE, create_flags, MYF(0));
129
130 if (unlikely((error= file < 0)))
131 {
132 if (my_errno == ENOENT)
133 my_error(ER_BAD_DB_ERROR, MYF(0), db);
134 else
135 my_error(ER_CANT_CREATE_TABLE, MYF(0), db, table, my_errno);
136 }
137 else
138 {
139 error= (int)mysql_file_write(file, frmdata, len, MYF(MY_WME | MY_NABP));
140
141 if (!error && !tmp_table && opt_sync_frm)
142 error= mysql_file_sync(file, MYF(MY_WME)) ||
143 my_sync_dir_by_file(file_name, MYF(MY_WME));
144
145 error|= mysql_file_close(file, MYF(MY_WME));
146 }
147 DBUG_RETURN(error);
148} /* writefrm */
149
150static inline void advance(FILEINFO* &from, FILEINFO* &to,
151 FILEINFO* cur, bool &skip)
152{
153 if (skip) // if not copying
154 from= cur; // just advance the start pointer
155 else // if copying
156 if (to == from) // but to the same place (not shifting the data)
157 from= to= cur; // advance both pointers
158 else // otherwise
159 while (from < cur) // have to copy [from...cur) to [to...)
160 *to++ = *from++;
161 skip= false;
162}
163
164/**
165 Go through the directory listing looking for files with a specified
166 extension and add them to the result list
167
168 @details
169 This function may be called many times on the same directory listing
170 but with different extensions. To avoid discovering the same table twice,
171 whenever a table file is discovered, all files with the same name
172 (independently from the extensions) are removed from the list.
173
174 Example: the list contained
175 { "db.opt", "t1.MYD", "t1.MYI", "t1.frm", "t2.ARZ", "t3.ARZ", "t3.frm" }
176 on discovering all ".frm" files, tables "t1" and "t3" will be found,
177 and list will become
178 { "db.opt", "t2.ARZ" }
179 and now ".ARZ" discovery can discover the table "t2"
180
181 @note
182 This function assumes that the directory listing is sorted alphabetically.
183
184 @note Partitioning makes this more complicated. A partitioned table t1 might
185 have files, like t1.frm, t1#P#part1.ibd, t1#P#foo.ibd, etc.
186 That means we need to compare file names only up to the first '#' or '.'
187 whichever comes first.
188*/
189int extension_based_table_discovery(MY_DIR *dirp, const char *ext_meta,
190 handlerton::discovered_list *result)
191{
192 CHARSET_INFO *cs= character_set_filesystem;
193 size_t ext_meta_len= strlen(ext_meta);
194 FILEINFO *from, *to, *cur, *end;
195 bool skip= false;
196
197 from= to= cur= dirp->dir_entry;
198 end= cur + dirp->number_of_files;
199 while (cur < end)
200 {
201 char *octothorp= strchr(cur->name + 1, '#');
202 char *ext= strchr(octothorp ? octothorp : cur->name, FN_EXTCHAR);
203
204 if (ext)
205 {
206 size_t len= (octothorp ? octothorp : ext) - cur->name;
207 if (from != cur &&
208 (strlen(from->name) <= len ||
209 my_strnncoll(cs, (uchar*)from->name, len, (uchar*)cur->name, len) ||
210 (from->name[len] != FN_EXTCHAR && from->name[len] != '#')))
211 advance(from, to, cur, skip);
212
213 if (my_strnncoll(cs, (uchar*)ext, strlen(ext),
214 (uchar*)ext_meta, ext_meta_len) == 0)
215 {
216 *ext = 0;
217 if (result->add_file(cur->name))
218 return 1;
219 *ext = FN_EXTCHAR;
220 skip= true; // table discovered, skip all files with the same name
221 }
222 }
223 else
224 {
225 advance(from, to, cur, skip);
226 from++;
227 }
228
229 cur++;
230 }
231 advance(from, to, cur, skip);
232 dirp->number_of_files= (uint)(to - dirp->dir_entry);
233 return 0;
234}
235
236/**
237 Simple, not reusable file-based table discovery
238
239 @details
240 simplified version of extension_based_table_discovery(), that does not
241 modify the list of files. It cannot be called many times for the same
242 directory listing, otherwise it'll produce duplicate results.
243*/
244int ext_table_discovery_simple(MY_DIR *dirp,
245 handlerton::discovered_list *result)
246{
247 CHARSET_INFO *cs= character_set_filesystem;
248 FILEINFO *cur, *end;
249
250 cur= dirp->dir_entry;
251 end= cur + dirp->number_of_files;
252 while (cur < end)
253 {
254 char *ext= strrchr(cur->name, FN_EXTCHAR);
255
256 if (ext)
257 {
258 if (my_strnncoll(cs, (uchar*)ext, strlen(ext),
259 (uchar*)reg_ext, reg_ext_length) == 0)
260 {
261 *ext = 0;
262 if (result->add_file(cur->name))
263 return 1;
264 }
265 }
266 cur++;
267 }
268 return 0;
269}
270
271