1 | /* gdbmreorg.c - Reorganize the database file. */
|
---|
2 |
|
---|
3 | /* This file is part of GDBM, the GNU data base manager, by Philip A. Nelson.
|
---|
4 | Copyright (C) 1990, 1991, 1993 Free Software Foundation, Inc.
|
---|
5 |
|
---|
6 | GDBM is free software; you can redistribute it and/or modify
|
---|
7 | it under the terms of the GNU General Public License as published by
|
---|
8 | the Free Software Foundation; either version 2, or (at your option)
|
---|
9 | any later version.
|
---|
10 |
|
---|
11 | GDBM is distributed in the hope that it will be useful,
|
---|
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of
|
---|
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
---|
14 | GNU General Public License for more details.
|
---|
15 |
|
---|
16 | You should have received a copy of the GNU General Public License
|
---|
17 | along with GDBM; see the file COPYING. If not, write to
|
---|
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
|
---|
19 |
|
---|
20 | You may contact the author by:
|
---|
21 | e-mail: [email protected]
|
---|
22 | us-mail: Philip A. Nelson
|
---|
23 | Computer Science Department
|
---|
24 | Western Washington University
|
---|
25 | Bellingham, WA 98226
|
---|
26 |
|
---|
27 | ************************************************************************/
|
---|
28 |
|
---|
29 |
|
---|
30 | /* AIX demands this be the very first thing in the file. */
|
---|
31 | #if !defined(__GNUC__) && defined(_AIX)
|
---|
32 | #pragma alloca
|
---|
33 | #endif
|
---|
34 |
|
---|
35 | /* include system configuration before all else. */
|
---|
36 | #include "autoconf.h"
|
---|
37 |
|
---|
38 | #include "gdbmdefs.h"
|
---|
39 | #include "gdbmerrno.h"
|
---|
40 | #include "extern.h"
|
---|
41 |
|
---|
42 | #if !HAVE_RENAME
|
---|
43 |
|
---|
44 | /* Rename takes OLD_NAME and renames it as NEW_NAME. If it can not rename
|
---|
45 | the file a non-zero value is returned. OLD_NAME is guaranteed to
|
---|
46 | remain if it can't be renamed. It assumes NEW_NAME always exists (due
|
---|
47 | to being used in gdbm). */
|
---|
48 |
|
---|
49 | static int
|
---|
50 | rename (old_name, new_name)
|
---|
51 | char* old_name;
|
---|
52 | char* new_name;
|
---|
53 | {
|
---|
54 | if (unlink (new_name) != 0)
|
---|
55 | return -1;
|
---|
56 |
|
---|
57 | if (link (old_name, new_name) != 0)
|
---|
58 | return -1;
|
---|
59 |
|
---|
60 | unlink (old_name);
|
---|
61 | return 0;
|
---|
62 |
|
---|
63 | }
|
---|
64 | #endif
|
---|
65 |
|
---|
66 |
|
---|
67 |
|
---|
68 | /* Reorganize the database. This requires creating a new file and inserting
|
---|
69 | all the elements in the old file DBF into the new file. The new file
|
---|
70 | is then renamed to the same name as the old file and DBF is updated to
|
---|
71 | contain all the correct information about the new file. If an error
|
---|
72 | is detected, the return value is negative. The value zero is returned
|
---|
73 | after a successful reorganization. */
|
---|
74 |
|
---|
75 | int
|
---|
76 | gdbm_reorganize (dbf)
|
---|
77 | gdbm_file_info *dbf;
|
---|
78 |
|
---|
79 | {
|
---|
80 | gdbm_file_info *new_dbf; /* The new file. */
|
---|
81 | char *new_name; /* A temporary name. */
|
---|
82 | int len; /* Used in new_name construction. */
|
---|
83 | datum key, nextkey, data; /* For the sequential sweep. */
|
---|
84 | struct stat fileinfo; /* Information about the file. */
|
---|
85 | int index; /* Use in moving the bucket cache. */
|
---|
86 |
|
---|
87 |
|
---|
88 | /* Readers can not reorganize! */
|
---|
89 | if (dbf->read_write == GDBM_READER)
|
---|
90 | {
|
---|
91 | gdbm_errno = GDBM_READER_CANT_REORGANIZE;
|
---|
92 | return -1;
|
---|
93 | }
|
---|
94 |
|
---|
95 | /* Initialize the gdbm_errno variable. */
|
---|
96 | gdbm_errno = GDBM_NO_ERROR;
|
---|
97 |
|
---|
98 | /* Construct new name for temporary file. */
|
---|
99 | len = strlen (dbf->name);
|
---|
100 | new_name = (char *) alloca (len + 3);
|
---|
101 | if (new_name == NULL)
|
---|
102 | {
|
---|
103 | gdbm_errno = GDBM_MALLOC_ERROR;
|
---|
104 | return -1;
|
---|
105 | }
|
---|
106 | strcpy (&new_name[0], dbf->name);
|
---|
107 | new_name[len+2] = 0;
|
---|
108 | new_name[len+1] = '#';
|
---|
109 | while ( (len > 0) && new_name[len-1] != '/')
|
---|
110 | {
|
---|
111 | new_name[len] = new_name[len-1];
|
---|
112 | len -= 1;
|
---|
113 | }
|
---|
114 | new_name[len] = '#';
|
---|
115 |
|
---|
116 | /* Get the mode for the old file and open the new database.
|
---|
117 | The "fast" mode is used because the reorganization will fail
|
---|
118 | unless we create a complete copy of the database. */
|
---|
119 | fstat (dbf->desc, &fileinfo);
|
---|
120 | new_dbf = gdbm_open (new_name, dbf->header->block_size,
|
---|
121 | GDBM_WRCREAT | GDBM_FAST,
|
---|
122 | fileinfo.st_mode, dbf->fatal_err);
|
---|
123 |
|
---|
124 | if (new_dbf == NULL)
|
---|
125 | {
|
---|
126 | gdbm_errno = GDBM_REORGANIZE_FAILED;
|
---|
127 | return -1;
|
---|
128 | }
|
---|
129 |
|
---|
130 |
|
---|
131 | /* For each item in the old database, add an entry in the new. */
|
---|
132 | key = gdbm_firstkey (dbf);
|
---|
133 |
|
---|
134 | while (key.dptr != NULL)
|
---|
135 | {
|
---|
136 | data = gdbm_fetch (dbf, key);
|
---|
137 | if (data.dptr != NULL)
|
---|
138 | {
|
---|
139 | /* Add the data to the new file. */
|
---|
140 | if (gdbm_store (new_dbf, key, data, GDBM_INSERT) != 0)
|
---|
141 | {
|
---|
142 | gdbm_close (new_dbf);
|
---|
143 | gdbm_errno = GDBM_REORGANIZE_FAILED;
|
---|
144 | unlink (new_name);
|
---|
145 | return -1;
|
---|
146 | }
|
---|
147 | }
|
---|
148 | else
|
---|
149 | {
|
---|
150 | /* ERROR! Abort and don't finish reorganize. */
|
---|
151 | gdbm_close (new_dbf);
|
---|
152 | gdbm_errno = GDBM_REORGANIZE_FAILED;
|
---|
153 | unlink (new_name);
|
---|
154 | return -1;
|
---|
155 | }
|
---|
156 | nextkey = gdbm_nextkey (dbf, key);
|
---|
157 | free (key.dptr);
|
---|
158 | free (data.dptr);
|
---|
159 | key = nextkey;
|
---|
160 | }
|
---|
161 |
|
---|
162 | /* Write everything. */
|
---|
163 | _gdbm_end_update (new_dbf);
|
---|
164 | gdbm_sync (new_dbf);
|
---|
165 |
|
---|
166 |
|
---|
167 | /* Move the new file to old name. */
|
---|
168 |
|
---|
169 | #ifdef MSDOS
|
---|
170 | if (close (new_dbf->desc)
|
---|
171 | || unlink (dbf->name)
|
---|
172 | || rename (new_name, dbf->name)
|
---|
173 | || (new_dbf->desc = open (dbf->name, O_RDWR|O_BINARY)) < 0)
|
---|
174 | #else /* not MSDOS */
|
---|
175 | if (rename (new_name, dbf->name) != 0)
|
---|
176 | #endif /* not MSDOS */
|
---|
177 | {
|
---|
178 | gdbm_errno = GDBM_REORGANIZE_FAILED;
|
---|
179 | gdbm_close (new_dbf);
|
---|
180 | return -1;
|
---|
181 | }
|
---|
182 |
|
---|
183 | /* Fix up DBF to have the correct information for the new file. */
|
---|
184 | if (dbf->need_filelock) {
|
---|
185 | UNLOCK_FILE(dbf);
|
---|
186 | }
|
---|
187 | close (dbf->desc);
|
---|
188 | free (dbf->header);
|
---|
189 | free (dbf->dir);
|
---|
190 |
|
---|
191 | if (dbf->bucket_cache != NULL) {
|
---|
192 | for (index = 0; index < dbf->cache_size; index++) {
|
---|
193 | if (dbf->bucket_cache[index].ca_bucket != NULL)
|
---|
194 | free (dbf->bucket_cache[index].ca_bucket);
|
---|
195 | if (dbf->bucket_cache[index].ca_data.dptr != NULL)
|
---|
196 | free (dbf->bucket_cache[index].ca_data.dptr);
|
---|
197 | }
|
---|
198 | free (dbf->bucket_cache);
|
---|
199 | }
|
---|
200 |
|
---|
201 | dbf->desc = new_dbf->desc;
|
---|
202 | dbf->header = new_dbf->header;
|
---|
203 | dbf->dir = new_dbf->dir;
|
---|
204 | dbf->bucket = new_dbf->bucket;
|
---|
205 | dbf->bucket_dir = new_dbf->bucket_dir;
|
---|
206 | dbf->last_read = new_dbf->last_read;
|
---|
207 | dbf->bucket_cache = new_dbf->bucket_cache;
|
---|
208 | dbf->cache_size = new_dbf->cache_size;
|
---|
209 | dbf->header_changed = new_dbf->header_changed;
|
---|
210 | dbf->directory_changed = new_dbf->directory_changed;
|
---|
211 | dbf->bucket_changed = new_dbf->bucket_changed;
|
---|
212 | dbf->second_changed = new_dbf->second_changed;
|
---|
213 |
|
---|
214 | free (new_dbf);
|
---|
215 |
|
---|
216 | /* Make sure the new database is all on disk. */
|
---|
217 | fsync (dbf->desc);
|
---|
218 |
|
---|
219 | /* Force the right stuff for a correct bucket cache. */
|
---|
220 | dbf->cache_entry = &dbf->bucket_cache[0];
|
---|
221 | _gdbm_get_bucket (dbf, 0);
|
---|
222 |
|
---|
223 | return 0;
|
---|
224 | }
|
---|