lib: Make directory document creation optional for _notmuch_directory_create
[notmuch] / lib / directory.cc
1 /* directory.cc - Results of directory-based searches from a notmuch database
2  *
3  * Copyright © 2009 Carl Worth
4  *
5  * This program is free software: you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation, either version 3 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see http://www.gnu.org/licenses/ .
17  *
18  * Author: Carl Worth <cworth@cworth.org>
19  */
20
21 #include "notmuch-private.h"
22 #include "database-private.h"
23
24 /* Create an iterator to iterate over the basenames of files (or
25  * directories) that all share a common parent directory.
26  */
27 static notmuch_filenames_t *
28 _create_filenames_for_terms_with_prefix (void *ctx,
29                                          notmuch_database_t *notmuch,
30                                          const char *prefix)
31 {
32     notmuch_string_list_t *filename_list;
33     Xapian::TermIterator i, end;
34
35     i = notmuch->xapian_db->allterms_begin();
36     end = notmuch->xapian_db->allterms_end();
37     filename_list = _notmuch_database_get_terms_with_prefix (ctx, i, end,
38                                                              prefix);
39     if (unlikely (filename_list == NULL))
40         return NULL;
41
42     return _notmuch_filenames_create (ctx, filename_list);
43 }
44
45 struct _notmuch_directory {
46     notmuch_database_t *notmuch;
47     Xapian::docid document_id;
48     Xapian::Document doc;
49     time_t mtime;
50 };
51
52 /* We end up having to call the destructor explicitly because we had
53  * to use "placement new" in order to initialize C++ objects within a
54  * block that we allocated with talloc. So C++ is making talloc
55  * slightly less simple to use, (we wouldn't need
56  * talloc_set_destructor at all otherwise).
57  */
58 static int
59 _notmuch_directory_destructor (notmuch_directory_t *directory)
60 {
61     directory->doc.~Document ();
62
63     return 0;
64 }
65
66 static notmuch_private_status_t
67 find_directory_document (notmuch_database_t *notmuch,
68                          const char *db_path,
69                          Xapian::Document *document)
70 {
71     notmuch_private_status_t status;
72     Xapian::docid doc_id;
73
74     status = _notmuch_database_find_unique_doc_id (notmuch, "directory",
75                                                    db_path, &doc_id);
76     if (status) {
77         *document = Xapian::Document ();
78         return status;
79     }
80
81     *document = notmuch->xapian_db->get_document (doc_id);
82     return NOTMUCH_PRIVATE_STATUS_SUCCESS;
83 }
84
85 /* Find or create a directory document.
86  *
87  * 'path' should be a path relative to the path of 'database', or else
88  * should be an absolute path with initial components that match the
89  * path of 'database'.
90  *
91  * If (flags & NOTMUCH_FIND_CREATE), then the directory document will
92  * be created if it does not exist.  Otherwise, if the directory
93  * document does not exist, *status_ret is set to
94  * NOTMUCH_STATUS_SUCCESS and this returns NULL.
95  */
96 notmuch_directory_t *
97 _notmuch_directory_create (notmuch_database_t *notmuch,
98                            const char *path,
99                            notmuch_find_flags_t flags,
100                            notmuch_status_t *status_ret)
101 {
102     Xapian::WritableDatabase *db;
103     notmuch_directory_t *directory;
104     notmuch_private_status_t private_status;
105     const char *db_path;
106     notmuch_bool_t create = (flags & NOTMUCH_FIND_CREATE);
107
108     *status_ret = NOTMUCH_STATUS_SUCCESS;
109
110     path = _notmuch_database_relative_path (notmuch, path);
111
112     if (create && notmuch->mode == NOTMUCH_DATABASE_MODE_READ_ONLY)
113         INTERNAL_ERROR ("Failure to ensure database is writable");
114
115     directory = talloc (notmuch, notmuch_directory_t);
116     if (unlikely (directory == NULL)) {
117         *status_ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
118         return NULL;
119     }
120
121     directory->notmuch = notmuch;
122
123     /* "placement new"---not actually allocating memory */
124     new (&directory->doc) Xapian::Document;
125
126     talloc_set_destructor (directory, _notmuch_directory_destructor);
127
128     db_path = _notmuch_database_get_directory_db_path (path);
129
130     try {
131         Xapian::TermIterator i, end;
132
133         private_status = find_directory_document (notmuch, db_path,
134                                                   &directory->doc);
135         directory->document_id = directory->doc.get_docid ();
136
137         if (private_status == NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND) {
138             if (!create) {
139                 notmuch_directory_destroy (directory);
140                 directory = NULL;
141                 *status_ret = NOTMUCH_STATUS_SUCCESS;
142                 goto DONE;
143             }
144
145             void *local = talloc_new (directory);
146             const char *parent, *basename;
147             Xapian::docid parent_id;
148             char *term = talloc_asprintf (local, "%s%s",
149                                           _find_prefix ("directory"), db_path);
150             directory->doc.add_term (term, 0);
151
152             directory->doc.set_data (path);
153
154             _notmuch_database_split_path (local, path, &parent, &basename);
155
156             _notmuch_database_find_directory_id (notmuch, parent, &parent_id);
157
158             if (basename) {
159                 term = talloc_asprintf (local, "%s%u:%s",
160                                         _find_prefix ("directory-direntry"),
161                                         parent_id, basename);
162                 directory->doc.add_term (term, 0);
163             }
164
165             directory->doc.add_value (NOTMUCH_VALUE_TIMESTAMP,
166                                       Xapian::sortable_serialise (0));
167
168             db = static_cast <Xapian::WritableDatabase *> (notmuch->xapian_db);
169
170             directory->document_id = _notmuch_database_generate_doc_id (notmuch);
171             db->replace_document (directory->document_id, directory->doc);
172             talloc_free (local);
173         }
174
175         directory->mtime = Xapian::sortable_unserialise (
176             directory->doc.get_value (NOTMUCH_VALUE_TIMESTAMP));
177     } catch (const Xapian::Error &error) {
178         fprintf (stderr,
179                  "A Xapian exception occurred creating a directory: %s.\n",
180                  error.get_msg().c_str());
181         notmuch->exception_reported = TRUE;
182         notmuch_directory_destroy (directory);
183         directory = NULL;
184         *status_ret = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
185     }
186
187   DONE:
188     if (db_path != path)
189         free ((char *) db_path);
190
191     return directory;
192 }
193
194 unsigned int
195 _notmuch_directory_get_document_id (notmuch_directory_t *directory)
196 {
197     return directory->document_id;
198 }
199
200 notmuch_status_t
201 notmuch_directory_set_mtime (notmuch_directory_t *directory,
202                              time_t mtime)
203 {
204     notmuch_database_t *notmuch = directory->notmuch;
205     Xapian::WritableDatabase *db;
206     notmuch_status_t status;
207
208     status = _notmuch_database_ensure_writable (notmuch);
209     if (status)
210         return status;
211
212     db = static_cast <Xapian::WritableDatabase *> (notmuch->xapian_db);
213
214     try {
215         directory->doc.add_value (NOTMUCH_VALUE_TIMESTAMP,
216                                    Xapian::sortable_serialise (mtime));
217
218         db->replace_document (directory->document_id, directory->doc);
219     } catch (const Xapian::Error &error) {
220         fprintf (stderr,
221                  "A Xapian exception occurred setting directory mtime: %s.\n",
222                  error.get_msg().c_str());
223         notmuch->exception_reported = TRUE;
224         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
225     }
226
227     return NOTMUCH_STATUS_SUCCESS;
228 }
229
230 time_t
231 notmuch_directory_get_mtime (notmuch_directory_t *directory)
232 {
233     return directory->mtime;
234 }
235
236 notmuch_filenames_t *
237 notmuch_directory_get_child_files (notmuch_directory_t *directory)
238 {
239     char *term;
240     notmuch_filenames_t *child_files;
241
242     term = talloc_asprintf (directory, "%s%u:",
243                             _find_prefix ("file-direntry"),
244                             directory->document_id);
245
246     child_files = _create_filenames_for_terms_with_prefix (directory,
247                                                            directory->notmuch,
248                                                            term);
249
250     talloc_free (term);
251
252     return child_files;
253 }
254
255 notmuch_filenames_t *
256 notmuch_directory_get_child_directories (notmuch_directory_t *directory)
257 {
258     char *term;
259     notmuch_filenames_t *child_directories;
260
261     term = talloc_asprintf (directory, "%s%u:",
262                             _find_prefix ("directory-direntry"),
263                             directory->document_id);
264
265     child_directories = _create_filenames_for_terms_with_prefix (directory,
266                                                  directory->notmuch, term);
267
268     talloc_free (term);
269
270     return child_directories;
271 }
272
273 void
274 notmuch_directory_destroy (notmuch_directory_t *directory)
275 {
276     talloc_free (directory);
277 }