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   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 https://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 struct _notmuch_query {
  27     notmuch_database_t *notmuch;
  28     const char *query_string;
  29     notmuch_sort_t sort;
  30     notmuch_string_list_t *exclude_terms;
  31     notmuch_exclude_t omit_excluded;
  32     bool parsed;
  33     Xapian::Query xapian_query;
  34     std::set<std::string> terms;
  35 };
  36
  37 typedef struct _notmuch_mset_messages {
  38     notmuch_messages_t base;
  39     notmuch_database_t *notmuch;
  40     Xapian::MSetIterator iterator;
  41     Xapian::MSetIterator iterator_end;
  42 } notmuch_mset_messages_t;
  43
  44 struct _notmuch_doc_id_set {
  45     unsigned char *bitmap;
  46     unsigned int bound;
  47 };
  48
  49 #define DOCIDSET_WORD(bit) ((bit) / CHAR_BIT)
  50 #define DOCIDSET_BIT(bit) ((bit) % CHAR_BIT)
  51
  52 struct _notmuch_threads {
  53     notmuch_query_t *query;
  54
  55     /* The ordered list of doc ids matched by the query. */
  56     GArray *doc_ids;
  57     /* Our iterator's current position in doc_ids. */
  58     unsigned int doc_id_pos;
  59     /* The set of matched docid's that have not been assigned to a
  60      * thread. Initially, this contains every docid in doc_ids. */
  61     notmuch_doc_id_set_t match_set;
  62 };
  63
  64 /* We need this in the message functions so forward declare. */
  65 static bool
  66 _notmuch_doc_id_set_init (void *ctx,
  67                           notmuch_doc_id_set_t *doc_ids,
  68                           GArray *arr);
  69
  70 static bool
  71 _debug_query (void)
  72 {
  73     char *env = getenv ("NOTMUCH_DEBUG_QUERY");
  74     return (env && strcmp (env, "") != 0);
  75 }
  76
  77 /* Explicit destructor call for placement new */
  78 static int
  79 _notmuch_query_destructor (notmuch_query_t *query) {
  80     query->xapian_query.~Query();
  81     query->terms.~set<std::string>();
  82     return 0;
  83 }
  84
  85 notmuch_query_t *
  86 notmuch_query_create (notmuch_database_t *notmuch,
  87                       const char *query_string)
  88 {
  89     notmuch_query_t *query;
  90
  91     if (_debug_query ())
  92         fprintf (stderr, "Query string is:\n%s\n", query_string);
  93
  94     query = talloc (notmuch, notmuch_query_t);
  95     if (unlikely (query == NULL))
  96         return NULL;
  97
  98     new (&query->xapian_query) Xapian::Query ();
  99     new (&query->terms) std::set<std::string> ();
 100     query->parsed = false;
 101
 102     talloc_set_destructor (query, _notmuch_query_destructor);
 103
 104     query->notmuch = notmuch;
 105
 106     query->query_string = talloc_strdup (query, query_string);
 107
 108     query->sort = NOTMUCH_SORT_NEWEST_FIRST;
 109
 110     query->exclude_terms = _notmuch_string_list_create (query);
 111
 112     query->omit_excluded = NOTMUCH_EXCLUDE_TRUE;
 113
 114     return query;
 115 }
 116
 117 static notmuch_status_t
 118 _notmuch_query_ensure_parsed (notmuch_query_t *query)
 119 {
 120     if (query->parsed)
 121         return NOTMUCH_STATUS_SUCCESS;
 122
 123     try {
 124         query->xapian_query =
 125             query->notmuch->query_parser->
 126                 parse_query (query->query_string, NOTMUCH_QUERY_PARSER_FLAGS);
 127
 128        /* Xapian doesn't support skip_to on terms from a query since
 129         *  they are unordered, so cache a copy of all terms in
 130         *  something searchable.
 131         */
 132
 133         for (Xapian::TermIterator t = query->xapian_query.get_terms_begin ();
 134              t != query->xapian_query.get_terms_end (); ++t)
 135             query->terms.insert (*t);
 136
 137         query->parsed = true;
 138
 139     } catch (const Xapian::Error &error) {
 140         if (!query->notmuch->exception_reported) {
 141             _notmuch_database_log (query->notmuch,
 142                                    "A Xapian exception occurred parsing query: %s\n",
 143                                    error.get_msg ().c_str ());
 144             _notmuch_database_log_append (query->notmuch,
 145                                           "Query string was: %s\n",
 146                                           query->query_string);
 147             query->notmuch->exception_reported = true;
 148         }
 149
 150         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 151     }
 152     return NOTMUCH_STATUS_SUCCESS;
 153 }
 154
 155 const char *
 156 notmuch_query_get_query_string (const notmuch_query_t *query)
 157 {
 158     return query->query_string;
 159 }
 160
 161 void
 162 notmuch_query_set_omit_excluded (notmuch_query_t *query,
 163                                  notmuch_exclude_t omit_excluded)
 164 {
 165     query->omit_excluded = omit_excluded;
 166 }
 167
 168 void
 169 notmuch_query_set_sort (notmuch_query_t *query, notmuch_sort_t sort)
 170 {
 171     query->sort = sort;
 172 }
 173
 174 notmuch_sort_t
 175 notmuch_query_get_sort (const notmuch_query_t *query)
 176 {
 177     return query->sort;
 178 }
 179
 180 notmuch_status_t
 181 notmuch_query_add_tag_exclude (notmuch_query_t *query, const char *tag)
 182 {
 183     notmuch_status_t status;
 184     char *term;
 185
 186     status = _notmuch_query_ensure_parsed (query);
 187     if (status)
 188         return status;
 189
 190     term = talloc_asprintf (query, "%s%s", _find_prefix ("tag"), tag);
 191     if (query->terms.count(term) != 0)
 192         return NOTMUCH_STATUS_IGNORED;
 193
 194     _notmuch_string_list_append (query->exclude_terms, term);
 195     return NOTMUCH_STATUS_SUCCESS;
 196 }
 197
 198 /* We end up having to call the destructors explicitly because we had
 199  * to use "placement new" in order to initialize C++ objects within a
 200  * block that we allocated with talloc. So C++ is making talloc
 201  * slightly less simple to use, (we wouldn't need
 202  * talloc_set_destructor at all otherwise).
 203  */
 204 static int
 205 _notmuch_messages_destructor (notmuch_mset_messages_t *messages)
 206 {
 207     messages->iterator.~MSetIterator ();
 208     messages->iterator_end.~MSetIterator ();
 209
 210     return 0;
 211 }
 212
 213 /* Return a query that matches messages with the excluded tags
 214  * registered with query. The caller of this function has to combine the returned
 215  * query appropriately.*/
 216 static Xapian::Query
 217 _notmuch_exclude_tags (notmuch_query_t *query)
 218 {
 219     Xapian::Query exclude_query = Xapian::Query::MatchNothing;
 220
 221     for (notmuch_string_node_t *term = query->exclude_terms->head; term;
 222          term = term->next) {
 223         exclude_query = Xapian::Query (Xapian::Query::OP_OR,
 224                                        exclude_query, Xapian::Query (term->string));
 225     }
 226     return exclude_query;
 227 }
 228
 229
 230 notmuch_status_t
 231 notmuch_query_search_messages_st (notmuch_query_t *query,
 232                                   notmuch_messages_t **out)
 233 {
 234     return notmuch_query_search_messages (query, out);
 235 }
 236
 237 notmuch_status_t
 238 notmuch_query_search_messages (notmuch_query_t *query,
 239                                   notmuch_messages_t **out)
 240 {
 241     return _notmuch_query_search_documents (query, "mail", out);
 242 }
 243
 244 notmuch_status_t
 245 _notmuch_query_search_documents (notmuch_query_t *query,
 246                                  const char *type,
 247                                  notmuch_messages_t **out)
 248 {
 249     notmuch_database_t *notmuch = query->notmuch;
 250     const char *query_string = query->query_string;
 251     notmuch_mset_messages_t *messages;
 252     notmuch_status_t status;
 253
 254     status = _notmuch_query_ensure_parsed (query);
 255     if (status)
 256         return status;
 257
 258     messages = talloc (query, notmuch_mset_messages_t);
 259     if (unlikely (messages == NULL))
 260         return NOTMUCH_STATUS_OUT_OF_MEMORY;
 261
 262     try {
 263
 264         messages->base.is_of_list_type = false;
 265         messages->base.iterator = NULL;
 266         messages->notmuch = notmuch;
 267         new (&messages->iterator) Xapian::MSetIterator ();
 268         new (&messages->iterator_end) Xapian::MSetIterator ();
 269
 270         talloc_set_destructor (messages, _notmuch_messages_destructor);
 271
 272         Xapian::Enquire enquire (*notmuch->xapian_db);
 273         Xapian::Query mail_query (talloc_asprintf (query, "%s%s",
 274                                                    _find_prefix ("type"),
 275                                                    type));
 276         Xapian::Query final_query, exclude_query;
 277         Xapian::MSet mset;
 278         Xapian::MSetIterator iterator;
 279
 280         if (strcmp (query_string, "") == 0 ||
 281             strcmp (query_string, "*") == 0)
 282         {
 283             final_query = mail_query;
 284         } else {
 285             final_query = Xapian::Query (Xapian::Query::OP_AND,
 286                                          mail_query, query->xapian_query);
 287         }
 288         messages->base.excluded_doc_ids = NULL;
 289
 290         if ((query->omit_excluded != NOTMUCH_EXCLUDE_FALSE) && (query->exclude_terms)) {
 291             exclude_query = _notmuch_exclude_tags (query);
 292
 293             if (query->omit_excluded == NOTMUCH_EXCLUDE_TRUE ||
 294                 query->omit_excluded == NOTMUCH_EXCLUDE_ALL)
 295             {
 296                 final_query = Xapian::Query (Xapian::Query::OP_AND_NOT,
 297                                              final_query, exclude_query);
 298             } else { /* NOTMUCH_EXCLUDE_FLAG */
 299                 exclude_query = Xapian::Query (Xapian::Query::OP_AND,
 300                                            exclude_query, final_query);
 301
 302                 enquire.set_weighting_scheme (Xapian::BoolWeight());
 303                 enquire.set_query (exclude_query);
 304
 305                 mset = enquire.get_mset (0, notmuch->xapian_db->get_doccount ());
 306
 307                 GArray *excluded_doc_ids = g_array_new (false, false, sizeof (unsigned int));
 308
 309                 for (iterator = mset.begin (); iterator != mset.end (); iterator++) {
 310                     unsigned int doc_id = *iterator;
 311                     g_array_append_val (excluded_doc_ids, doc_id);
 312                 }
 313                 messages->base.excluded_doc_ids = talloc (messages, _notmuch_doc_id_set);
 314                 _notmuch_doc_id_set_init (query, messages->base.excluded_doc_ids,
 315                                           excluded_doc_ids);
 316                 g_array_unref (excluded_doc_ids);
 317             }
 318         }
 319
 320
 321         enquire.set_weighting_scheme (Xapian::BoolWeight());
 322
 323         switch (query->sort) {
 324         case NOTMUCH_SORT_OLDEST_FIRST:
 325             enquire.set_sort_by_value (NOTMUCH_VALUE_TIMESTAMP, false);
 326             break;
 327         case NOTMUCH_SORT_NEWEST_FIRST:
 328             enquire.set_sort_by_value (NOTMUCH_VALUE_TIMESTAMP, true);
 329             break;
 330         case NOTMUCH_SORT_MESSAGE_ID:
 331             enquire.set_sort_by_value (NOTMUCH_VALUE_MESSAGE_ID, false);
 332             break;
 333         case NOTMUCH_SORT_UNSORTED:
 334             break;
 335         }
 336
 337         if (_debug_query ()) {
 338             fprintf (stderr, "Exclude query is:\n%s\n",
 339                      exclude_query.get_description ().c_str ());
 340             fprintf (stderr, "Final query is:\n%s\n",
 341                      final_query.get_description ().c_str ());
 342         }
 343
 344         enquire.set_query (final_query);
 345
 346         mset = enquire.get_mset (0, notmuch->xapian_db->get_doccount ());
 347
 348         messages->iterator = mset.begin ();
 349         messages->iterator_end = mset.end ();
 350
 351         *out = &messages->base;
 352         return NOTMUCH_STATUS_SUCCESS;
 353
 354     } catch (const Xapian::Error &error) {
 355         _notmuch_database_log (notmuch,
 356                                "A Xapian exception occurred performing query: %s\n",
 357                                error.get_msg().c_str());
 358         _notmuch_database_log_append (notmuch,
 359                                "Query string was: %s\n",
 360                                query->query_string);
 361
 362         notmuch->exception_reported = true;
 363         talloc_free (messages);
 364         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 365     }
 366 }
 367
 368 bool
 369 _notmuch_mset_messages_valid (notmuch_messages_t *messages)
 370 {
 371     notmuch_mset_messages_t *mset_messages;
 372
 373     mset_messages = (notmuch_mset_messages_t *) messages;
 374
 375     return (mset_messages->iterator != mset_messages->iterator_end);
 376 }
 377
 378 static Xapian::docid
 379 _notmuch_mset_messages_get_doc_id (notmuch_messages_t *messages)
 380 {
 381     notmuch_mset_messages_t *mset_messages;
 382
 383     mset_messages = (notmuch_mset_messages_t *) messages;
 384
 385     if (! _notmuch_mset_messages_valid (&mset_messages->base))
 386         return 0;
 387
 388     return *mset_messages->iterator;
 389 }
 390
 391 notmuch_message_t *
 392 _notmuch_mset_messages_get (notmuch_messages_t *messages)
 393 {
 394     notmuch_message_t *message;
 395     Xapian::docid doc_id;
 396     notmuch_private_status_t status;
 397     notmuch_mset_messages_t *mset_messages;
 398
 399     mset_messages = (notmuch_mset_messages_t *) messages;
 400
 401     if (! _notmuch_mset_messages_valid (&mset_messages->base))
 402         return NULL;
 403
 404     doc_id = *mset_messages->iterator;
 405
 406     message = _notmuch_message_create (mset_messages,
 407                                        mset_messages->notmuch, doc_id,
 408                                        &status);
 409
 410     if (message == NULL &&
 411        status == NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND)
 412     {
 413         INTERNAL_ERROR ("a messages iterator contains a non-existent document ID.\n");
 414     }
 415
 416     if (messages->excluded_doc_ids &&
 417         _notmuch_doc_id_set_contains (messages->excluded_doc_ids, doc_id))
 418         notmuch_message_set_flag (message, NOTMUCH_MESSAGE_FLAG_EXCLUDED, true);
 419
 420     return message;
 421 }
 422
 423 void
 424 _notmuch_mset_messages_move_to_next (notmuch_messages_t *messages)
 425 {
 426     notmuch_mset_messages_t *mset_messages;
 427
 428     mset_messages = (notmuch_mset_messages_t *) messages;
 429
 430     mset_messages->iterator++;
 431 }
 432
 433 static bool
 434 _notmuch_doc_id_set_init (void *ctx,
 435                           notmuch_doc_id_set_t *doc_ids,
 436                           GArray *arr)
 437 {
 438     unsigned int max = 0;
 439     unsigned char *bitmap;
 440
 441     for (unsigned int i = 0; i < arr->len; i++)
 442         max = MAX(max, g_array_index (arr, unsigned int, i));
 443     bitmap = talloc_zero_array (ctx, unsigned char, DOCIDSET_WORD(max) + 1);
 444
 445     if (bitmap == NULL)
 446         return false;
 447
 448     doc_ids->bitmap = bitmap;
 449     doc_ids->bound = max + 1;
 450
 451     for (unsigned int i = 0; i < arr->len; i++) {
 452         unsigned int doc_id = g_array_index (arr, unsigned int, i);
 453         bitmap[DOCIDSET_WORD(doc_id)] |= 1 << DOCIDSET_BIT(doc_id);
 454     }
 455
 456     return true;
 457 }
 458
 459 bool
 460 _notmuch_doc_id_set_contains (notmuch_doc_id_set_t *doc_ids,
 461                               unsigned int doc_id)
 462 {
 463     if (doc_id >= doc_ids->bound)
 464         return false;
 465     return doc_ids->bitmap[DOCIDSET_WORD(doc_id)] & (1 << DOCIDSET_BIT(doc_id));
 466 }
 467
 468 void
 469 _notmuch_doc_id_set_remove (notmuch_doc_id_set_t *doc_ids,
 470                             unsigned int doc_id)
 471 {
 472     if (doc_id < doc_ids->bound)
 473         doc_ids->bitmap[DOCIDSET_WORD(doc_id)] &= ~(1 << DOCIDSET_BIT(doc_id));
 474 }
 475
 476 /* Glib objects force use to use a talloc destructor as well, (but not
 477  * nearly as ugly as the for messages due to C++ objects). At
 478  * this point, I'd really like to have some talloc-friendly
 479  * equivalents for the few pieces of glib that I'm using. */
 480 static int
 481 _notmuch_threads_destructor (notmuch_threads_t *threads)
 482 {
 483     if (threads->doc_ids)
 484         g_array_unref (threads->doc_ids);
 485
 486     return 0;
 487 }
 488
 489 notmuch_status_t
 490 notmuch_query_search_threads_st (notmuch_query_t *query, notmuch_threads_t **out)
 491 {
 492     return notmuch_query_search_threads(query, out);
 493 }
 494
 495 notmuch_status_t
 496 notmuch_query_search_threads (notmuch_query_t *query,
 497                               notmuch_threads_t **out)
 498 {
 499     notmuch_threads_t *threads;
 500     notmuch_messages_t *messages;
 501     notmuch_status_t status;
 502
 503     threads = talloc (query, notmuch_threads_t);
 504     if (threads == NULL)
 505         return NOTMUCH_STATUS_OUT_OF_MEMORY;
 506     threads->doc_ids = NULL;
 507     talloc_set_destructor (threads, _notmuch_threads_destructor);
 508
 509     threads->query = query;
 510
 511     status = notmuch_query_search_messages (query, &messages);
 512     if (status) {
 513         talloc_free (threads);
 514         return status;
 515     }
 516
 517     threads->doc_ids = g_array_new (false, false, sizeof (unsigned int));
 518     while (notmuch_messages_valid (messages)) {
 519         unsigned int doc_id = _notmuch_mset_messages_get_doc_id (messages);
 520         g_array_append_val (threads->doc_ids, doc_id);
 521         notmuch_messages_move_to_next (messages);
 522     }
 523     threads->doc_id_pos = 0;
 524
 525     talloc_free (messages);
 526
 527     if (! _notmuch_doc_id_set_init (threads, &threads->match_set,
 528                                     threads->doc_ids)) {
 529         talloc_free (threads);
 530         return NOTMUCH_STATUS_OUT_OF_MEMORY;
 531     }
 532
 533     *out = threads;
 534     return NOTMUCH_STATUS_SUCCESS;
 535 }
 536
 537 void
 538 notmuch_query_destroy (notmuch_query_t *query)
 539 {
 540     talloc_free (query);
 541 }
 542
 543 notmuch_bool_t
 544 notmuch_threads_valid (notmuch_threads_t *threads)
 545 {
 546     unsigned int doc_id;
 547
 548     if (! threads)
 549         return false;
 550
 551     while (threads->doc_id_pos < threads->doc_ids->len) {
 552         doc_id = g_array_index (threads->doc_ids, unsigned int,
 553                                 threads->doc_id_pos);
 554         if (_notmuch_doc_id_set_contains (&threads->match_set, doc_id))
 555             break;
 556
 557         threads->doc_id_pos++;
 558     }
 559
 560     return threads->doc_id_pos < threads->doc_ids->len;
 561 }
 562
 563 notmuch_thread_t *
 564 notmuch_threads_get (notmuch_threads_t *threads)
 565 {
 566     unsigned int doc_id;
 567
 568     if (! notmuch_threads_valid (threads))
 569         return NULL;
 570
 571     doc_id = g_array_index (threads->doc_ids, unsigned int,
 572                             threads->doc_id_pos);
 573     return _notmuch_thread_create (threads->query,
 574                                    threads->query->notmuch,
 575                                    doc_id,
 576                                    &threads->match_set,
 577                                    threads->query->exclude_terms,
 578                                    threads->query->omit_excluded,
 579                                    threads->query->sort);
 580 }
 581
 582 void
 583 notmuch_threads_move_to_next (notmuch_threads_t *threads)
 584 {
 585     threads->doc_id_pos++;
 586 }
 587
 588 void
 589 notmuch_threads_destroy (notmuch_threads_t *threads)
 590 {
 591     talloc_free (threads);
 592 }
 593
 594 notmuch_status_t
 595 notmuch_query_count_messages_st (notmuch_query_t *query, unsigned *count_out)
 596 {
 597     return notmuch_query_count_messages (query, count_out);
 598 }
 599
 600 notmuch_status_t
 601 notmuch_query_count_messages (notmuch_query_t *query, unsigned *count_out)
 602 {
 603     return _notmuch_query_count_documents (query, "mail", count_out);
 604 }
 605
 606 notmuch_status_t
 607 _notmuch_query_count_documents (notmuch_query_t *query, const char *type, unsigned *count_out)
 608 {
 609     notmuch_database_t *notmuch = query->notmuch;
 610     const char *query_string = query->query_string;
 611     Xapian::doccount count = 0;
 612     notmuch_status_t status;
 613
 614     status = _notmuch_query_ensure_parsed (query);
 615     if (status)
 616         return status;
 617
 618     try {
 619         Xapian::Enquire enquire (*notmuch->xapian_db);
 620         Xapian::Query mail_query (talloc_asprintf (query, "%s%s",
 621                                                    _find_prefix ("type"),
 622                                                    type));
 623         Xapian::Query final_query, exclude_query;
 624         Xapian::MSet mset;
 625
 626         if (strcmp (query_string, "") == 0 ||
 627             strcmp (query_string, "*") == 0)
 628         {
 629             final_query = mail_query;
 630         } else {
 631             final_query = Xapian::Query (Xapian::Query::OP_AND,
 632                                          mail_query, query->xapian_query);
 633         }
 634
 635         exclude_query = _notmuch_exclude_tags (query);
 636
 637         final_query = Xapian::Query (Xapian::Query::OP_AND_NOT,
 638                                          final_query, exclude_query);
 639
 640         enquire.set_weighting_scheme(Xapian::BoolWeight());
 641         enquire.set_docid_order(Xapian::Enquire::ASCENDING);
 642
 643         if (_debug_query ()) {
 644             fprintf (stderr, "Exclude query is:\n%s\n",
 645                      exclude_query.get_description ().c_str ());
 646             fprintf (stderr, "Final query is:\n%s\n",
 647                      final_query.get_description ().c_str ());
 648         }
 649
 650         enquire.set_query (final_query);
 651
 652         /*
 653          * Set the checkatleast parameter to the number of documents
 654          * in the database to make get_matches_estimated() exact.
 655          * Set the max parameter to 0 to avoid fetching documents we will discard.
 656          */
 657         mset = enquire.get_mset (0, 0,
 658                                  notmuch->xapian_db->get_doccount ());
 659
 660         count = mset.get_matches_estimated();
 661
 662     } catch (const Xapian::Error &error) {
 663         _notmuch_database_log (notmuch,
 664                                "A Xapian exception occurred performing query: %s\n",
 665                                error.get_msg().c_str());
 666         _notmuch_database_log_append (notmuch,
 667                                       "Query string was: %s\n",
 668                                       query->query_string);
 669         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 670     }
 671
 672     *count_out = count;
 673     return NOTMUCH_STATUS_SUCCESS;
 674 }
 675
 676 notmuch_status_t
 677 notmuch_query_count_threads_st (notmuch_query_t *query, unsigned *count)
 678 {
 679     return notmuch_query_count_threads (query, count);
 680 }
 681
 682 notmuch_status_t
 683 notmuch_query_count_threads (notmuch_query_t *query, unsigned *count)
 684 {
 685     notmuch_messages_t *messages;
 686     GHashTable *hash;
 687     notmuch_sort_t sort;
 688     notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
 689
 690     sort = query->sort;
 691     query->sort = NOTMUCH_SORT_UNSORTED;
 692     ret = notmuch_query_search_messages (query, &messages);
 693     if (ret)
 694         return ret;
 695     query->sort = sort;
 696     if (messages == NULL)
 697         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 698
 699     hash = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, NULL);
 700     if (hash == NULL) {
 701         talloc_free (messages);
 702         return NOTMUCH_STATUS_OUT_OF_MEMORY;
 703     }
 704
 705     while (notmuch_messages_valid (messages)) {
 706         notmuch_message_t *message = notmuch_messages_get (messages);
 707         const char *thread_id = notmuch_message_get_thread_id (message);
 708         char *thread_id_copy = talloc_strdup (messages, thread_id);
 709         if (unlikely (thread_id_copy == NULL)) {
 710             notmuch_message_destroy (message);
 711             ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
 712             goto DONE;
 713         }
 714         g_hash_table_insert (hash, thread_id_copy, NULL);
 715         notmuch_message_destroy (message);
 716         notmuch_messages_move_to_next (messages);
 717     }
 718
 719     *count = g_hash_table_size (hash);
 720
 721   DONE:
 722     g_hash_table_unref (hash);
 723     talloc_free (messages);
 724
 725     return ret;
 726 }
 727
 728 notmuch_database_t *
 729 notmuch_query_get_database (const notmuch_query_t *query)
 730 {
 731     return query->notmuch;
 732 }