git.cworth.org Git - notmuch/blob - 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 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     notmuch_query_syntax_t syntax;
  34     Xapian::Query xapian_query;
  35     std::set<std::string> terms;
  36 };
  37
  38 typedef struct _notmuch_mset_messages {
  39     notmuch_messages_t base;
  40     notmuch_database_t *notmuch;
  41     Xapian::MSetIterator iterator;
  42     Xapian::MSetIterator iterator_end;
  43 } notmuch_mset_messages_t;
  44
  45 struct _notmuch_doc_id_set {
  46     unsigned char *bitmap;
  47     unsigned int bound;
  48 };
  49
  50 #define DOCIDSET_WORD(bit) ((bit) / CHAR_BIT)
  51 #define DOCIDSET_BIT(bit) ((bit) % CHAR_BIT)
  52
  53 struct _notmuch_threads {
  54     notmuch_query_t *query;
  55
  56     /* The ordered list of doc ids matched by the query. */
  57     GArray *doc_ids;
  58     /* Our iterator's current position in doc_ids. */
  59     unsigned int doc_id_pos;
  60     /* The set of matched docid's that have not been assigned to a
  61      * thread. Initially, this contains every docid in doc_ids. */
  62     notmuch_doc_id_set_t match_set;
  63 };
  64
  65 /* We need this in the message functions so forward declare. */
  66 static bool
  67 _notmuch_doc_id_set_init (void *ctx,
  68                           notmuch_doc_id_set_t *doc_ids,
  69                           GArray *arr);
  70
  71 static bool
  72 _debug_query (void)
  73 {
  74     char *env = getenv ("NOTMUCH_DEBUG_QUERY");
  75
  76     return (env && strcmp (env, "") != 0);
  77 }
  78
  79 /* Explicit destructor call for placement new */
  80 static int
  81 _notmuch_query_destructor (notmuch_query_t *query)
  82 {
  83     query->xapian_query.~Query();
  84     query->terms.~set<std::string>();
  85     return 0;
  86 }
  87
  88 static notmuch_query_t *
  89 _notmuch_query_constructor (notmuch_database_t *notmuch,
  90                             const char *query_string)
  91 {
  92     notmuch_query_t *query;
  93
  94     if (_debug_query ())
  95         fprintf (stderr, "Query string is:\n%s\n", query_string);
  96
  97     query = talloc (notmuch, notmuch_query_t);
  98     if (unlikely (query == NULL))
  99         return NULL;
 100
 101     new (&query->xapian_query) Xapian::Query ();
 102     new (&query->terms) std::set<std::string> ();
 103     query->parsed = false;
 104
 105     talloc_set_destructor (query, _notmuch_query_destructor);
 106
 107     query->notmuch = notmuch;
 108
 109     if (query_string)
 110         query->query_string = talloc_strdup (query, query_string);
 111     else
 112         query->query_string = NULL;
 113
 114     query->sort = NOTMUCH_SORT_NEWEST_FIRST;
 115
 116     query->exclude_terms = _notmuch_string_list_create (query);
 117
 118     query->omit_excluded = NOTMUCH_EXCLUDE_TRUE;
 119
 120     return query;
 121 }
 122
 123 notmuch_query_t *
 124 notmuch_query_create (notmuch_database_t *notmuch,
 125                       const char *query_string)
 126 {
 127
 128     notmuch_query_t *query;
 129     notmuch_status_t status;
 130
 131     status = notmuch_query_create_with_syntax (notmuch, query_string,
 132                                                NOTMUCH_QUERY_SYNTAX_XAPIAN,
 133                                                &query);
 134     if (status)
 135         return NULL;
 136
 137     return query;
 138 }
 139
 140 notmuch_status_t
 141 notmuch_query_create_with_syntax (notmuch_database_t *notmuch,
 142                                   const char *query_string,
 143                                   notmuch_query_syntax_t syntax,
 144                                   notmuch_query_t **output)
 145 {
 146
 147     notmuch_query_t *query;
 148
 149     if (! output)
 150         return NOTMUCH_STATUS_NULL_POINTER;
 151
 152     query = _notmuch_query_constructor (notmuch, query_string);
 153     if (! query)
 154         return NOTMUCH_STATUS_OUT_OF_MEMORY;
 155
 156     if (syntax == NOTMUCH_QUERY_SYNTAX_SEXP && ! HAVE_SFSEXP) {
 157         _notmuch_database_log (notmuch, "sexp query parser not available");
 158         return NOTMUCH_STATUS_ILLEGAL_ARGUMENT;
 159     }
 160
 161     query->syntax = syntax;
 162
 163     *output = query;
 164
 165     return NOTMUCH_STATUS_SUCCESS;
 166 }
 167
 168 static void
 169 _notmuch_query_cache_terms (notmuch_query_t *query)
 170 {
 171     /* Xapian doesn't support skip_to on terms from a query since
 172      *  they are unordered, so cache a copy of all terms in
 173      *  something searchable.
 174      */
 175
 176     for (Xapian::TermIterator t = query->xapian_query.get_terms_begin ();
 177          t != query->xapian_query.get_terms_end (); ++t)
 178         query->terms.insert (*t);
 179 }
 180
 181 notmuch_status_t
 182 _notmuch_query_string_to_xapian_query (notmuch_database_t *notmuch,
 183                                        std::string query_string,
 184                                        Xapian::Query &output,
 185                                        std::string &msg)
 186 {
 187     try {
 188         if (query_string == "" || query_string == "*") {
 189             output = Xapian::Query::MatchAll;
 190         } else {
 191             output =
 192                 notmuch->query_parser->
 193                 parse_query (query_string, NOTMUCH_QUERY_PARSER_FLAGS);
 194         }
 195     } catch (const Xapian::Error &error) {
 196         if (! notmuch->exception_reported) {
 197             _notmuch_database_log (notmuch,
 198                                    "A Xapian exception occurred parsing query: %s\n",
 199                                    error.get_msg ().c_str ());
 200             _notmuch_database_log_append (notmuch,
 201                                           "Query string was: %s\n",
 202                                           query_string.c_str ());
 203             notmuch->exception_reported = true;
 204         }
 205
 206         msg = error.get_msg ();
 207         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 208     }
 209     return NOTMUCH_STATUS_SUCCESS;
 210 }
 211
 212 static notmuch_status_t
 213 _notmuch_query_ensure_parsed_xapian (notmuch_query_t *query)
 214 {
 215     notmuch_status_t status;
 216     std::string msg; /* ignored */
 217
 218     status =  _notmuch_query_string_to_xapian_query (query->notmuch, query->query_string,
 219                                                      query->xapian_query, msg);
 220     if (status)
 221         return status;
 222
 223     query->parsed = true;
 224
 225     _notmuch_query_cache_terms (query);
 226
 227     return NOTMUCH_STATUS_SUCCESS;
 228 }
 229
 230 #if HAVE_SFSEXP
 231 static notmuch_status_t
 232 _notmuch_query_ensure_parsed_sexpr (notmuch_query_t *query)
 233 {
 234     notmuch_status_t status;
 235
 236     if (query->parsed)
 237         return NOTMUCH_STATUS_SUCCESS;
 238
 239     status = _notmuch_sexp_string_to_xapian_query (query->notmuch, query->query_string,
 240                                                    query->xapian_query);
 241     if (status)
 242         return status;
 243
 244     _notmuch_query_cache_terms (query);
 245     return NOTMUCH_STATUS_SUCCESS;
 246 }
 247 #endif
 248
 249 static notmuch_status_t
 250 _notmuch_query_ensure_parsed (notmuch_query_t *query)
 251 {
 252     if (query->parsed)
 253         return NOTMUCH_STATUS_SUCCESS;
 254
 255 #if HAVE_SFSEXP
 256     if (query->syntax == NOTMUCH_QUERY_SYNTAX_SEXP)
 257         return _notmuch_query_ensure_parsed_sexpr (query);
 258 #endif
 259
 260     return _notmuch_query_ensure_parsed_xapian (query);
 261 }
 262
 263 const char *
 264 notmuch_query_get_query_string (const notmuch_query_t *query)
 265 {
 266     return query->query_string;
 267 }
 268
 269 void
 270 notmuch_query_set_omit_excluded (notmuch_query_t *query,
 271                                  notmuch_exclude_t omit_excluded)
 272 {
 273     query->omit_excluded = omit_excluded;
 274 }
 275
 276 void
 277 notmuch_query_set_sort (notmuch_query_t *query, notmuch_sort_t sort)
 278 {
 279     query->sort = sort;
 280 }
 281
 282 notmuch_sort_t
 283 notmuch_query_get_sort (const notmuch_query_t *query)
 284 {
 285     return query->sort;
 286 }
 287
 288 notmuch_status_t
 289 notmuch_query_add_tag_exclude (notmuch_query_t *query, const char *tag)
 290 {
 291     notmuch_status_t status;
 292     char *term;
 293
 294     status = _notmuch_query_ensure_parsed (query);
 295     if (status)
 296         return status;
 297
 298     term = talloc_asprintf (query, "%s%s", _find_prefix ("tag"), tag);
 299     if (query->terms.count (term) != 0)
 300         return NOTMUCH_STATUS_IGNORED;
 301
 302     _notmuch_string_list_append (query->exclude_terms, term);
 303     return NOTMUCH_STATUS_SUCCESS;
 304 }
 305
 306 /* We end up having to call the destructors explicitly because we had
 307  * to use "placement new" in order to initialize C++ objects within a
 308  * block that we allocated with talloc. So C++ is making talloc
 309  * slightly less simple to use, (we wouldn't need
 310  * talloc_set_destructor at all otherwise).
 311  */
 312 static int
 313 _notmuch_messages_destructor (notmuch_mset_messages_t *messages)
 314 {
 315     messages->iterator.~MSetIterator ();
 316     messages->iterator_end.~MSetIterator ();
 317
 318     return 0;
 319 }
 320
 321 /* Return a query that matches messages with the excluded tags
 322  * registered with query. The caller of this function has to combine the returned
 323  * query appropriately.*/
 324 static Xapian::Query
 325 _notmuch_exclude_tags (notmuch_query_t *query)
 326 {
 327     Xapian::Query exclude_query = Xapian::Query::MatchNothing;
 328
 329     for (notmuch_string_node_t *term = query->exclude_terms->head; term;
 330          term = term->next) {
 331         exclude_query = Xapian::Query (Xapian::Query::OP_OR,
 332                                        exclude_query, Xapian::Query (term->string));
 333     }
 334     return exclude_query;
 335 }
 336
 337
 338 notmuch_status_t
 339 notmuch_query_search_messages_st (notmuch_query_t *query,
 340                                   notmuch_messages_t **out)
 341 {
 342     return notmuch_query_search_messages (query, out);
 343 }
 344
 345 notmuch_status_t
 346 notmuch_query_search_messages (notmuch_query_t *query,
 347                                notmuch_messages_t **out)
 348 {
 349     return _notmuch_query_search_documents (query, "mail", out);
 350 }
 351
 352 notmuch_status_t
 353 _notmuch_query_search_documents (notmuch_query_t *query,
 354                                  const char *type,
 355                                  notmuch_messages_t **out)
 356 {
 357     notmuch_database_t *notmuch = query->notmuch;
 358     notmuch_mset_messages_t *messages;
 359     notmuch_status_t status;
 360
 361     status = _notmuch_query_ensure_parsed (query);
 362     if (status)
 363         return status;
 364
 365     messages = talloc (query, notmuch_mset_messages_t);
 366     if (unlikely (messages == NULL))
 367         return NOTMUCH_STATUS_OUT_OF_MEMORY;
 368
 369     try {
 370
 371         messages->base.is_of_list_type = false;
 372         messages->base.iterator = NULL;
 373         messages->notmuch = notmuch;
 374         new (&messages->iterator) Xapian::MSetIterator ();
 375         new (&messages->iterator_end) Xapian::MSetIterator ();
 376
 377         talloc_set_destructor (messages, _notmuch_messages_destructor);
 378
 379         Xapian::Enquire enquire (*notmuch->xapian_db);
 380         Xapian::Query mail_query (talloc_asprintf (query, "%s%s",
 381                                                    _find_prefix ("type"),
 382                                                    type));
 383         Xapian::Query final_query, exclude_query;
 384         Xapian::MSet mset;
 385         Xapian::MSetIterator iterator;
 386
 387         final_query = Xapian::Query (Xapian::Query::OP_AND,
 388                                      mail_query, query->xapian_query);
 389
 390         messages->base.excluded_doc_ids = NULL;
 391
 392         if ((query->omit_excluded != NOTMUCH_EXCLUDE_FALSE) && (query->exclude_terms)) {
 393             exclude_query = _notmuch_exclude_tags (query);
 394
 395             if (query->omit_excluded == NOTMUCH_EXCLUDE_TRUE ||
 396                 query->omit_excluded == NOTMUCH_EXCLUDE_ALL) {
 397                 final_query = Xapian::Query (Xapian::Query::OP_AND_NOT,
 398                                              final_query, exclude_query);
 399             } else { /* NOTMUCH_EXCLUDE_FLAG */
 400                 exclude_query = Xapian::Query (Xapian::Query::OP_AND,
 401                                                exclude_query, final_query);
 402
 403                 enquire.set_weighting_scheme (Xapian::BoolWeight ());
 404                 enquire.set_query (exclude_query);
 405
 406                 mset = enquire.get_mset (0, notmuch->xapian_db->get_doccount ());
 407
 408                 GArray *excluded_doc_ids = g_array_new (false, false, sizeof (unsigned int));
 409
 410                 for (iterator = mset.begin (); iterator != mset.end (); iterator++) {
 411                     unsigned int doc_id = *iterator;
 412                     g_array_append_val (excluded_doc_ids, doc_id);
 413                 }
 414                 messages->base.excluded_doc_ids = talloc (messages, _notmuch_doc_id_set);
 415                 _notmuch_doc_id_set_init (query, messages->base.excluded_doc_ids,
 416                                           excluded_doc_ids);
 417                 g_array_unref (excluded_doc_ids);
 418             }
 419         }
 420
 421
 422         enquire.set_weighting_scheme (Xapian::BoolWeight ());
 423
 424         switch (query->sort) {
 425         case NOTMUCH_SORT_OLDEST_FIRST:
 426             enquire.set_sort_by_value (NOTMUCH_VALUE_TIMESTAMP, false);
 427             break;
 428         case NOTMUCH_SORT_NEWEST_FIRST:
 429             enquire.set_sort_by_value (NOTMUCH_VALUE_TIMESTAMP, true);
 430             break;
 431         case NOTMUCH_SORT_MESSAGE_ID:
 432             enquire.set_sort_by_value (NOTMUCH_VALUE_MESSAGE_ID, false);
 433             break;
 434         case NOTMUCH_SORT_UNSORTED:
 435             break;
 436         }
 437
 438         if (_debug_query ()) {
 439             fprintf (stderr, "Exclude query is:\n%s\n",
 440                      exclude_query.get_description ().c_str ());
 441             fprintf (stderr, "Final query is:\n%s\n",
 442                      final_query.get_description ().c_str ());
 443         }
 444
 445         enquire.set_query (final_query);
 446
 447         mset = enquire.get_mset (0, notmuch->xapian_db->get_doccount ());
 448
 449         messages->iterator = mset.begin ();
 450         messages->iterator_end = mset.end ();
 451
 452         *out = &messages->base;
 453         return NOTMUCH_STATUS_SUCCESS;
 454
 455     } catch (const Xapian::Error &error) {
 456         _notmuch_database_log (notmuch,
 457                                "A Xapian exception occurred performing query: %s\n",
 458                                error.get_msg ().c_str ());
 459         _notmuch_database_log_append (notmuch,
 460                                       "Query string was: %s\n",
 461                                       query->query_string);
 462
 463         notmuch->exception_reported = true;
 464         talloc_free (messages);
 465         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 466     }
 467 }
 468
 469 bool
 470 _notmuch_mset_messages_valid (notmuch_messages_t *messages)
 471 {
 472     notmuch_mset_messages_t *mset_messages;
 473
 474     mset_messages = (notmuch_mset_messages_t *) messages;
 475
 476     return (mset_messages->iterator != mset_messages->iterator_end);
 477 }
 478
 479 static Xapian::docid
 480 _notmuch_mset_messages_get_doc_id (notmuch_messages_t *messages)
 481 {
 482     notmuch_mset_messages_t *mset_messages;
 483
 484     mset_messages = (notmuch_mset_messages_t *) messages;
 485
 486     if (! _notmuch_mset_messages_valid (&mset_messages->base))
 487         return 0;
 488
 489     return *mset_messages->iterator;
 490 }
 491
 492 notmuch_message_t *
 493 _notmuch_mset_messages_get (notmuch_messages_t *messages)
 494 {
 495     notmuch_message_t *message;
 496     Xapian::docid doc_id;
 497     notmuch_private_status_t status;
 498     notmuch_mset_messages_t *mset_messages;
 499
 500     mset_messages = (notmuch_mset_messages_t *) messages;
 501
 502     if (! _notmuch_mset_messages_valid (&mset_messages->base))
 503         return NULL;
 504
 505     doc_id = *mset_messages->iterator;
 506
 507     message = _notmuch_message_create (mset_messages,
 508                                        mset_messages->notmuch, doc_id,
 509                                        &status);
 510
 511     if (message == NULL &&
 512         status == NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND) {
 513         INTERNAL_ERROR ("a messages iterator contains a non-existent document ID.\n");
 514     }
 515
 516     if (messages->excluded_doc_ids &&
 517         _notmuch_doc_id_set_contains (messages->excluded_doc_ids, doc_id))
 518         notmuch_message_set_flag (message, NOTMUCH_MESSAGE_FLAG_EXCLUDED, true);
 519
 520     return message;
 521 }
 522
 523 void
 524 _notmuch_mset_messages_move_to_next (notmuch_messages_t *messages)
 525 {
 526     notmuch_mset_messages_t *mset_messages;
 527
 528     mset_messages = (notmuch_mset_messages_t *) messages;
 529
 530     mset_messages->iterator++;
 531 }
 532
 533 static bool
 534 _notmuch_doc_id_set_init (void *ctx,
 535                           notmuch_doc_id_set_t *doc_ids,
 536                           GArray *arr)
 537 {
 538     unsigned int max = 0;
 539     unsigned char *bitmap;
 540
 541     for (unsigned int i = 0; i < arr->len; i++)
 542         max = MAX (max, g_array_index (arr, unsigned int, i));
 543     bitmap = talloc_zero_array (ctx, unsigned char, DOCIDSET_WORD (max) + 1);
 544
 545     if (bitmap == NULL)
 546         return false;
 547
 548     doc_ids->bitmap = bitmap;
 549     doc_ids->bound = max + 1;
 550
 551     for (unsigned int i = 0; i < arr->len; i++) {
 552         unsigned int doc_id = g_array_index (arr, unsigned int, i);
 553         bitmap[DOCIDSET_WORD (doc_id)] |= 1 << DOCIDSET_BIT (doc_id);
 554     }
 555
 556     return true;
 557 }
 558
 559 bool
 560 _notmuch_doc_id_set_contains (notmuch_doc_id_set_t *doc_ids,
 561                               unsigned int doc_id)
 562 {
 563     if (doc_id >= doc_ids->bound)
 564         return false;
 565     return doc_ids->bitmap[DOCIDSET_WORD (doc_id)] & (1 << DOCIDSET_BIT (doc_id));
 566 }
 567
 568 void
 569 _notmuch_doc_id_set_remove (notmuch_doc_id_set_t *doc_ids,
 570                             unsigned int doc_id)
 571 {
 572     if (doc_id < doc_ids->bound)
 573         doc_ids->bitmap[DOCIDSET_WORD (doc_id)] &= ~(1 << DOCIDSET_BIT (doc_id));
 574 }
 575
 576 /* Glib objects force use to use a talloc destructor as well, (but not
 577  * nearly as ugly as the for messages due to C++ objects). At
 578  * this point, I'd really like to have some talloc-friendly
 579  * equivalents for the few pieces of glib that I'm using. */
 580 static int
 581 _notmuch_threads_destructor (notmuch_threads_t *threads)
 582 {
 583     if (threads->doc_ids)
 584         g_array_unref (threads->doc_ids);
 585
 586     return 0;
 587 }
 588
 589 notmuch_status_t
 590 notmuch_query_search_threads_st (notmuch_query_t *query, notmuch_threads_t **out)
 591 {
 592     return notmuch_query_search_threads (query, out);
 593 }
 594
 595 notmuch_status_t
 596 notmuch_query_search_threads (notmuch_query_t *query,
 597                               notmuch_threads_t **out)
 598 {
 599     notmuch_threads_t *threads;
 600     notmuch_messages_t *messages;
 601     notmuch_status_t status;
 602
 603     threads = talloc (query, notmuch_threads_t);
 604     if (threads == NULL)
 605         return NOTMUCH_STATUS_OUT_OF_MEMORY;
 606     threads->doc_ids = NULL;
 607     talloc_set_destructor (threads, _notmuch_threads_destructor);
 608
 609     threads->query = query;
 610
 611     status = notmuch_query_search_messages (query, &messages);
 612     if (status) {
 613         talloc_free (threads);
 614         return status;
 615     }
 616
 617     threads->doc_ids = g_array_new (false, false, sizeof (unsigned int));
 618     while (notmuch_messages_valid (messages)) {
 619         unsigned int doc_id = _notmuch_mset_messages_get_doc_id (messages);
 620         g_array_append_val (threads->doc_ids, doc_id);
 621         notmuch_messages_move_to_next (messages);
 622     }
 623     threads->doc_id_pos = 0;
 624
 625     talloc_free (messages);
 626
 627     if (! _notmuch_doc_id_set_init (threads, &threads->match_set,
 628                                     threads->doc_ids)) {
 629         talloc_free (threads);
 630         return NOTMUCH_STATUS_OUT_OF_MEMORY;
 631     }
 632
 633     *out = threads;
 634     return NOTMUCH_STATUS_SUCCESS;
 635 }
 636
 637 void
 638 notmuch_query_destroy (notmuch_query_t *query)
 639 {
 640     talloc_free (query);
 641 }
 642
 643 notmuch_bool_t
 644 notmuch_threads_valid (notmuch_threads_t *threads)
 645 {
 646     unsigned int doc_id;
 647
 648     if (! threads)
 649         return false;
 650
 651     while (threads->doc_id_pos < threads->doc_ids->len) {
 652         doc_id = g_array_index (threads->doc_ids, unsigned int,
 653                                 threads->doc_id_pos);
 654         if (_notmuch_doc_id_set_contains (&threads->match_set, doc_id))
 655             break;
 656
 657         threads->doc_id_pos++;
 658     }
 659
 660     return threads->doc_id_pos < threads->doc_ids->len;
 661 }
 662
 663 notmuch_thread_t *
 664 notmuch_threads_get (notmuch_threads_t *threads)
 665 {
 666     unsigned int doc_id;
 667
 668     if (! notmuch_threads_valid (threads))
 669         return NULL;
 670
 671     doc_id = g_array_index (threads->doc_ids, unsigned int,
 672                             threads->doc_id_pos);
 673     return _notmuch_thread_create (threads->query,
 674                                    threads->query->notmuch,
 675                                    doc_id,
 676                                    &threads->match_set,
 677                                    threads->query->exclude_terms,
 678                                    threads->query->omit_excluded,
 679                                    threads->query->sort);
 680 }
 681
 682 void
 683 notmuch_threads_move_to_next (notmuch_threads_t *threads)
 684 {
 685     threads->doc_id_pos++;
 686 }
 687
 688 void
 689 notmuch_threads_destroy (notmuch_threads_t *threads)
 690 {
 691     talloc_free (threads);
 692 }
 693
 694 notmuch_status_t
 695 notmuch_query_count_messages_st (notmuch_query_t *query, unsigned *count_out)
 696 {
 697     return notmuch_query_count_messages (query, count_out);
 698 }
 699
 700 notmuch_status_t
 701 notmuch_query_count_messages (notmuch_query_t *query, unsigned *count_out)
 702 {
 703     return _notmuch_query_count_documents (query, "mail", count_out);
 704 }
 705
 706 notmuch_status_t
 707 _notmuch_query_count_documents (notmuch_query_t *query, const char *type, unsigned *count_out)
 708 {
 709     notmuch_database_t *notmuch = query->notmuch;
 710     Xapian::doccount count = 0;
 711     notmuch_status_t status;
 712
 713     status = _notmuch_query_ensure_parsed (query);
 714     if (status)
 715         return status;
 716
 717     try {
 718         Xapian::Enquire enquire (*notmuch->xapian_db);
 719         Xapian::Query mail_query (talloc_asprintf (query, "%s%s",
 720                                                    _find_prefix ("type"),
 721                                                    type));
 722         Xapian::Query final_query, exclude_query;
 723         Xapian::MSet mset;
 724
 725         final_query = Xapian::Query (Xapian::Query::OP_AND,
 726                                      mail_query, query->xapian_query);
 727
 728         exclude_query = _notmuch_exclude_tags (query);
 729
 730         final_query = Xapian::Query (Xapian::Query::OP_AND_NOT,
 731                                      final_query, exclude_query);
 732
 733         enquire.set_weighting_scheme (Xapian::BoolWeight ());
 734         enquire.set_docid_order (Xapian::Enquire::ASCENDING);
 735
 736         if (_debug_query ()) {
 737             fprintf (stderr, "Exclude query is:\n%s\n",
 738                      exclude_query.get_description ().c_str ());
 739             fprintf (stderr, "Final query is:\n%s\n",
 740                      final_query.get_description ().c_str ());
 741         }
 742
 743         enquire.set_query (final_query);
 744
 745         /*
 746          * Set the checkatleast parameter to the number of documents
 747          * in the database to make get_matches_estimated() exact.
 748          * Set the max parameter to 1 to avoid fetching documents we will discard.
 749          */
 750         mset = enquire.get_mset (0, 1,
 751                                  notmuch->xapian_db->get_doccount ());
 752
 753         count = mset.get_matches_estimated ();
 754
 755     } catch (const Xapian::Error &error) {
 756         _notmuch_database_log (notmuch,
 757                                "A Xapian exception occurred performing query: %s\n",
 758                                error.get_msg ().c_str ());
 759         _notmuch_database_log_append (notmuch,
 760                                       "Query string was: %s\n",
 761                                       query->query_string);
 762         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 763     }
 764
 765     *count_out = count;
 766     return NOTMUCH_STATUS_SUCCESS;
 767 }
 768
 769 notmuch_status_t
 770 notmuch_query_count_threads_st (notmuch_query_t *query, unsigned *count)
 771 {
 772     return notmuch_query_count_threads (query, count);
 773 }
 774
 775 notmuch_status_t
 776 notmuch_query_count_threads (notmuch_query_t *query, unsigned *count)
 777 {
 778     notmuch_messages_t *messages;
 779     GHashTable *hash;
 780     notmuch_sort_t sort;
 781     notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
 782
 783     sort = query->sort;
 784     query->sort = NOTMUCH_SORT_UNSORTED;
 785     ret = notmuch_query_search_messages (query, &messages);
 786     if (ret)
 787         return ret;
 788     query->sort = sort;
 789     if (messages == NULL)
 790         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 791
 792     hash = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, NULL);
 793     if (hash == NULL) {
 794         talloc_free (messages);
 795         return NOTMUCH_STATUS_OUT_OF_MEMORY;
 796     }
 797
 798     while (notmuch_messages_valid (messages)) {
 799         notmuch_message_t *message = notmuch_messages_get (messages);
 800         const char *thread_id = notmuch_message_get_thread_id (message);
 801         char *thread_id_copy = talloc_strdup (messages, thread_id);
 802         if (unlikely (thread_id_copy == NULL)) {
 803             notmuch_message_destroy (message);
 804             ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
 805             goto DONE;
 806         }
 807         g_hash_table_insert (hash, thread_id_copy, NULL);
 808         notmuch_message_destroy (message);
 809         notmuch_messages_move_to_next (messages);
 810     }
 811
 812     *count = g_hash_table_size (hash);
 813
 814   DONE:
 815     g_hash_table_unref (hash);
 816     talloc_free (messages);
 817
 818     return ret;
 819 }
 820
 821 notmuch_database_t *
 822 notmuch_query_get_database (const notmuch_query_t *query)
 823 {
 824     return query->notmuch;
 825 }
 826
 827 notmuch_status_t
 828 _notmuch_query_expand (notmuch_database_t *notmuch, const char *field, Xapian::Query subquery,
 829                        Xapian::Query &output, std::string &msg)
 830 {
 831     std::set<std::string> terms;
 832     const std::string term_prefix =  _find_prefix (field);
 833
 834     if (_debug_query ()) {
 835         fprintf (stderr, "Expanding subquery:\n%s\n",
 836                  subquery.get_description ().c_str ());
 837     }
 838
 839     try {
 840         Xapian::Enquire enquire (*notmuch->xapian_db);
 841         Xapian::MSet mset;
 842
 843         enquire.set_weighting_scheme (Xapian::BoolWeight ());
 844         enquire.set_query (subquery);
 845
 846         mset = enquire.get_mset (0, notmuch->xapian_db->get_doccount ());
 847
 848         for (Xapian::MSetIterator iterator = mset.begin (); iterator != mset.end (); iterator++) {
 849             Xapian::docid doc_id = *iterator;
 850             Xapian::Document doc = notmuch->xapian_db->get_document (doc_id);
 851             Xapian::TermIterator i = doc.termlist_begin ();
 852
 853             for (i.skip_to (term_prefix);
 854                  i != doc.termlist_end () && ((*i).rfind (term_prefix, 0) == 0); i++) {
 855                 terms.insert (*i);
 856             }
 857         }
 858         output = Xapian::Query (Xapian::Query::OP_OR, terms.begin (), terms.end ());
 859         if (_debug_query ()) {
 860             fprintf (stderr, "Expanded query:\n%s\n",
 861                      subquery.get_description ().c_str ());
 862         }
 863
 864     } catch (const Xapian::Error &error) {
 865         _notmuch_database_log (notmuch,
 866                                "A Xapian exception occurred expanding query: %s\n",
 867                                error.get_msg ().c_str ());
 868         msg = error.get_msg ();
 869         return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 870     }
 871
 872     return NOTMUCH_STATUS_SUCCESS;
 873 }