Silence compiler warning by initializing a variable.
[notmuch] / lib / query.cc
1 /* query.cc - Support for searching 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 #include <glib.h> /* GHashTable, GPtrArray */
25
26 #include <xapian.h>
27
28 struct _notmuch_query {
29     notmuch_database_t *notmuch;
30     const char *query_string;
31     notmuch_sort_t sort;
32 };
33
34 typedef struct _notmuch_mset_messages {
35     notmuch_messages_t base;
36     notmuch_database_t *notmuch;
37     Xapian::MSetIterator iterator;
38     Xapian::MSetIterator iterator_end;
39 } notmuch_mset_messages_t;
40
41 struct _notmuch_threads {
42     notmuch_query_t *query;
43     GHashTable *threads;
44     notmuch_messages_t *messages;
45
46     /* This thread ID is our iterator state. */
47     const char *thread_id;
48 };
49
50 notmuch_query_t *
51 notmuch_query_create (notmuch_database_t *notmuch,
52                       const char *query_string)
53 {
54     notmuch_query_t *query;
55
56 #ifdef DEBUG_QUERY
57     fprintf (stderr, "Query string is:\n%s\n", query_string);
58 #endif
59
60     query = talloc (NULL, notmuch_query_t);
61     if (unlikely (query == NULL))
62         return NULL;
63
64     query->notmuch = notmuch;
65
66     query->query_string = talloc_strdup (query, query_string);
67
68     query->sort = NOTMUCH_SORT_NEWEST_FIRST;
69
70     return query;
71 }
72
73 void
74 notmuch_query_set_sort (notmuch_query_t *query, notmuch_sort_t sort)
75 {
76     query->sort = sort;
77 }
78
79 /* We end up having to call the destructors explicitly because we had
80  * to use "placement new" in order to initialize C++ objects within a
81  * block that we allocated with talloc. So C++ is making talloc
82  * slightly less simple to use, (we wouldn't need
83  * talloc_set_destructor at all otherwise).
84  */
85 static int
86 _notmuch_messages_destructor (notmuch_mset_messages_t *messages)
87 {
88     messages->iterator.~MSetIterator ();
89     messages->iterator_end.~MSetIterator ();
90
91     return 0;
92 }
93
94 notmuch_messages_t *
95 notmuch_query_search_messages (notmuch_query_t *query)
96 {
97     notmuch_database_t *notmuch = query->notmuch;
98     const char *query_string = query->query_string;
99     notmuch_mset_messages_t *messages;
100
101     messages = talloc (query, notmuch_mset_messages_t);
102     if (unlikely (messages == NULL))
103         return NULL;
104
105     try {
106
107         messages->base.is_of_list_type = FALSE;
108         messages->base.iterator = NULL;
109         messages->notmuch = notmuch;
110         new (&messages->iterator) Xapian::MSetIterator ();
111         new (&messages->iterator_end) Xapian::MSetIterator ();
112
113         talloc_set_destructor (messages, _notmuch_messages_destructor);
114
115         Xapian::Enquire enquire (*notmuch->xapian_db);
116         Xapian::Query mail_query (talloc_asprintf (query, "%s%s",
117                                                    _find_prefix ("type"),
118                                                    "mail"));
119         Xapian::Query string_query, final_query;
120         Xapian::MSet mset;
121         unsigned int flags = (Xapian::QueryParser::FLAG_BOOLEAN |
122                               Xapian::QueryParser::FLAG_PHRASE |
123                               Xapian::QueryParser::FLAG_LOVEHATE |
124                               Xapian::QueryParser::FLAG_BOOLEAN_ANY_CASE |
125                               Xapian::QueryParser::FLAG_WILDCARD |
126                               Xapian::QueryParser::FLAG_PURE_NOT);
127
128         if (strcmp (query_string, "") == 0) {
129             final_query = mail_query;
130         } else {
131             string_query = notmuch->query_parser->
132                 parse_query (query_string, flags);
133             final_query = Xapian::Query (Xapian::Query::OP_AND,
134                                          mail_query, string_query);
135         }
136
137         switch (query->sort) {
138         case NOTMUCH_SORT_OLDEST_FIRST:
139             enquire.set_sort_by_value (NOTMUCH_VALUE_TIMESTAMP, FALSE);
140             break;
141         case NOTMUCH_SORT_NEWEST_FIRST:
142             enquire.set_sort_by_value (NOTMUCH_VALUE_TIMESTAMP, TRUE);
143             break;
144         case NOTMUCH_SORT_MESSAGE_ID:
145             enquire.set_sort_by_value (NOTMUCH_VALUE_MESSAGE_ID, FALSE);
146             break;
147         }
148
149 #if DEBUG_QUERY
150         fprintf (stderr, "Final query is:\n%s\n", final_query.get_description().c_str());
151 #endif
152
153         enquire.set_query (final_query);
154
155         mset = enquire.get_mset (0, notmuch->xapian_db->get_doccount ());
156
157         messages->iterator = mset.begin ();
158         messages->iterator_end = mset.end ();
159
160     } catch (const Xapian::Error &error) {
161         fprintf (stderr, "A Xapian exception occurred performing query: %s\n",
162                  error.get_msg().c_str());
163         fprintf (stderr, "Query string was: %s\n", query->query_string);
164         notmuch->exception_reported = TRUE;
165     }
166
167     return &messages->base;
168 }
169
170 notmuch_bool_t
171 _notmuch_mset_messages_has_more (notmuch_messages_t *messages)
172 {
173     notmuch_mset_messages_t *mset_messages;
174
175     mset_messages = (notmuch_mset_messages_t *) messages;
176
177     return (mset_messages->iterator != mset_messages->iterator_end);
178 }
179
180 notmuch_message_t *
181 _notmuch_mset_messages_get (notmuch_messages_t *messages)
182 {
183     notmuch_message_t *message;
184     Xapian::docid doc_id;
185     notmuch_private_status_t status;
186     notmuch_mset_messages_t *mset_messages;
187
188     mset_messages = (notmuch_mset_messages_t *) messages;
189
190     if (! _notmuch_mset_messages_has_more (&mset_messages->base))
191         return NULL;
192
193     doc_id = *mset_messages->iterator;
194
195     message = _notmuch_message_create (mset_messages,
196                                        mset_messages->notmuch, doc_id,
197                                        &status);
198
199     if (message == NULL &&
200        status == NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND)
201     {
202         INTERNAL_ERROR ("a messages iterator contains a non-existent document ID.\n");
203     }
204
205     return message;
206 }
207
208 void
209 _notmuch_mset_messages_advance (notmuch_messages_t *messages)
210 {
211     notmuch_mset_messages_t *mset_messages;
212
213     mset_messages = (notmuch_mset_messages_t *) messages;
214
215     mset_messages->iterator++;
216 }
217
218 /* Glib objects force use to use a talloc destructor as well, (but not
219  * nearly as ugly as the for messages due to C++ objects). At
220  * this point, I'd really like to have some talloc-friendly
221  * equivalents for the few pieces of glib that I'm using. */
222 static int
223 _notmuch_threads_destructor (notmuch_threads_t *threads)
224 {
225     g_hash_table_unref (threads->threads);
226
227     return 0;
228 }
229
230 notmuch_threads_t *
231 notmuch_query_search_threads (notmuch_query_t *query)
232 {
233     notmuch_threads_t *threads;
234
235     threads = talloc (query, notmuch_threads_t);
236     if (threads == NULL)
237         return NULL;
238
239     threads->query = query;
240     threads->threads = g_hash_table_new_full (g_str_hash, g_str_equal,
241                                               free, NULL);
242
243     threads->messages = notmuch_query_search_messages (query);
244
245     threads->thread_id = NULL;
246
247     talloc_set_destructor (threads, _notmuch_threads_destructor);
248
249     return threads;
250 }
251
252 void
253 notmuch_query_destroy (notmuch_query_t *query)
254 {
255     talloc_free (query);
256 }
257
258 notmuch_bool_t
259 notmuch_threads_has_more (notmuch_threads_t *threads)
260 {
261     notmuch_message_t *message;
262
263     if (threads->thread_id)
264         return TRUE;
265
266     while (notmuch_messages_has_more (threads->messages))
267     {
268         message = notmuch_messages_get (threads->messages);
269
270         threads->thread_id = notmuch_message_get_thread_id (message);
271
272         if (! g_hash_table_lookup_extended (threads->threads,
273                                             threads->thread_id,
274                                             NULL, NULL))
275         {
276             g_hash_table_insert (threads->threads,
277                                  xstrdup (threads->thread_id), NULL);
278             notmuch_messages_advance (threads->messages);
279             return TRUE;
280         }
281
282         notmuch_messages_advance (threads->messages);
283     }
284
285     threads->thread_id = NULL;
286     return FALSE;
287 }
288
289 notmuch_thread_t *
290 notmuch_threads_get (notmuch_threads_t *threads)
291 {
292     if (! notmuch_threads_has_more (threads))
293         return NULL;
294
295     return _notmuch_thread_create (threads->query,
296                                    threads->query->notmuch,
297                                    threads->thread_id,
298                                    threads->query->query_string);
299 }
300
301 void
302 notmuch_threads_advance (notmuch_threads_t *threads)
303 {
304     threads->thread_id = NULL;
305 }
306
307 void
308 notmuch_threads_destroy (notmuch_threads_t *threads)
309 {
310     talloc_free (threads);
311 }
312
313 unsigned
314 notmuch_query_count_messages (notmuch_query_t *query)
315 {
316     notmuch_database_t *notmuch = query->notmuch;
317     const char *query_string = query->query_string;
318     Xapian::doccount count = 0;
319
320     try {
321         Xapian::Enquire enquire (*notmuch->xapian_db);
322         Xapian::Query mail_query (talloc_asprintf (query, "%s%s",
323                                                    _find_prefix ("type"),
324                                                    "mail"));
325         Xapian::Query string_query, final_query;
326         Xapian::MSet mset;
327         unsigned int flags = (Xapian::QueryParser::FLAG_BOOLEAN |
328                               Xapian::QueryParser::FLAG_PHRASE |
329                               Xapian::QueryParser::FLAG_LOVEHATE |
330                               Xapian::QueryParser::FLAG_BOOLEAN_ANY_CASE |
331                               Xapian::QueryParser::FLAG_WILDCARD |
332                               Xapian::QueryParser::FLAG_PURE_NOT);
333
334         if (strcmp (query_string, "") == 0) {
335             final_query = mail_query;
336         } else {
337             string_query = notmuch->query_parser->
338                 parse_query (query_string, flags);
339             final_query = Xapian::Query (Xapian::Query::OP_AND,
340                                          mail_query, string_query);
341         }
342
343         enquire.set_weighting_scheme(Xapian::BoolWeight());
344         enquire.set_docid_order(Xapian::Enquire::ASCENDING);
345
346 #if DEBUG_QUERY
347         fprintf (stderr, "Final query is:\n%s\n", final_query.get_description().c_str());
348 #endif
349
350         enquire.set_query (final_query);
351
352         mset = enquire.get_mset (0, notmuch->xapian_db->get_doccount ());
353
354         count = mset.get_matches_estimated();
355
356     } catch (const Xapian::Error &error) {
357         fprintf (stderr, "A Xapian exception occurred: %s\n",
358                  error.get_msg().c_str());
359         fprintf (stderr, "Query string was: %s\n", query->query_string);
360     }
361
362     return count;
363 }