1 /* notmuch - Not much of an email library, (just index and search)
3 * Copyright © 2009 Carl Worth
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.
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.
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/ .
18 * Author: Carl Worth <cworth@cworth.org>
25 # define NOTMUCH_BEGIN_DECLS extern "C" {
26 # define NOTMUCH_END_DECLS }
28 # define NOTMUCH_BEGIN_DECLS
29 # define NOTMUCH_END_DECLS
44 typedef int notmuch_bool_t;
46 /* Status codes used for the return values of most functions.
48 * A zero value (NOTMUCH_STATUS_SUCCESS) indicates that the function
49 * completed without error. Any other value indicates an error as
52 * NOTMUCH_STATUS_SUCCESS: No error occurred.
54 * NOTMUCH_STATUS_OUT_OF_MEMORY: Out of memory
56 * XXX: We don't really want to expose this lame XAPIAN_EXCEPTION
57 * value. Instead we should map to things like DATABASE_LOCKED or
60 * NOTMUCH_STATUS_READ_ONLY_DATABASE: An attempt was made to write to
61 * a database opened in read-only mode.
63 * NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception occurred
65 * NOTMUCH_STATUS_FILE_ERROR: An error occurred trying to read or
66 * write to a file (this could be file not found, permission
69 * NOTMUCH_STATUS_FILE_NOT_EMAIL: A file was presented that doesn't
70 * appear to be an email message.
72 * NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID: A file contains a message ID
73 * that is identical to a message already in the database.
75 * NOTMUCH_STATUS_NULL_POINTER: The user erroneously passed a NULL
76 * pointer to a notmuch function.
78 * NOTMUCH_STATUS_TAG_TOO_LONG: A tag value is too long (exceeds
81 * NOTMUCH_STATUS_UNBALANCED_FREEZE_THAW: The notmuch_message_thaw
82 * function has been called more times than notmuch_message_freeze.
86 * NOTMUCH_STATUS_LAST_STATUS: Not an actual status value. Just a way
87 * to find out how many valid status values there are.
89 typedef enum _notmuch_status {
90 NOTMUCH_STATUS_SUCCESS = 0,
91 NOTMUCH_STATUS_OUT_OF_MEMORY,
92 NOTMUCH_STATUS_READ_ONLY_DATABASE,
93 NOTMUCH_STATUS_XAPIAN_EXCEPTION,
94 NOTMUCH_STATUS_FILE_ERROR,
95 NOTMUCH_STATUS_FILE_NOT_EMAIL,
96 NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID,
97 NOTMUCH_STATUS_NULL_POINTER,
98 NOTMUCH_STATUS_TAG_TOO_LONG,
99 NOTMUCH_STATUS_UNBALANCED_FREEZE_THAW,
101 NOTMUCH_STATUS_LAST_STATUS
104 /* Get a string representation of a notmuch_status_t value.
106 * The result is readonly.
109 notmuch_status_to_string (notmuch_status_t status);
111 /* Various opaque data types. For each notmuch_<foo>_t see the various
112 * notmuch_<foo> functions below. */
113 typedef struct _notmuch_database notmuch_database_t;
114 typedef struct _notmuch_query notmuch_query_t;
115 typedef struct _notmuch_threads notmuch_threads_t;
116 typedef struct _notmuch_thread notmuch_thread_t;
117 typedef struct _notmuch_messages notmuch_messages_t;
118 typedef struct _notmuch_message notmuch_message_t;
119 typedef struct _notmuch_tags notmuch_tags_t;
120 typedef struct _notmuch_directory notmuch_directory_t;
121 typedef struct _notmuch_filenames notmuch_filenames_t;
123 /* Create a new, empty notmuch database located at 'path'.
125 * The path should be a top-level directory to a collection of
126 * plain-text email messages (one message per file). This call will
127 * create a new ".notmuch" directory within 'path' where notmuch will
130 * After a successful call to notmuch_database_create, the returned
131 * database will be open so the caller should call
132 * notmuch_database_close when finished with it.
134 * The database will not yet have any data in it
135 * (notmuch_database_create itself is a very cheap function). Messages
136 * contained within 'path' can be added to the database by calling
137 * notmuch_database_add_message.
139 * In case of any failure, this function returns NULL, (after printing
140 * an error message on stderr).
143 notmuch_database_create (const char *path);
146 NOTMUCH_DATABASE_MODE_READ_ONLY = 0,
147 NOTMUCH_DATABASE_MODE_READ_WRITE
148 } notmuch_database_mode_t;
150 /* XXX: I think I'd like this to take an extra argument of
151 * notmuch_status_t* for returning a status value on failure. */
153 /* Open an existing notmuch database located at 'path'.
155 * The database should have been created at some time in the past,
156 * (not necessarily by this process), by calling
157 * notmuch_database_create with 'path'. By default the database should be
158 * opened for reading only. In order to write to the database you need to
159 * pass the NOTMUCH_DATABASE_MODE_WRITABLE mode.
161 * An existing notmuch database can be identified by the presence of a
162 * directory named ".notmuch" below 'path'.
164 * The caller should call notmuch_database_close when finished with
167 * In case of any failure, this function returns NULL, (after printing
168 * an error message on stderr).
171 notmuch_database_open (const char *path,
172 notmuch_database_mode_t mode);
174 /* Close the given notmuch database, freeing all associated
175 * resources. See notmuch_database_open. */
177 notmuch_database_close (notmuch_database_t *database);
179 /* Return the database path of the given database.
181 * The return value is a string owned by notmuch so should not be
182 * modified nor freed by the caller. */
184 notmuch_database_get_path (notmuch_database_t *database);
186 /* Return the database format version of the given database. */
188 notmuch_database_get_version (notmuch_database_t *database);
190 /* Does this database need to be upgraded before writing to it?
192 * If this function returns TRUE then no functions that modify the
193 * database (notmuch_database_add_message, notmuch_message_add_tag,
194 * notmuch_directory_set_mtime, etc.) will work unless the function
195 * notmuch_database_upgrade is called successfully first. */
197 notmuch_database_needs_upgrade (notmuch_database_t *database);
199 /* Upgrade the current database.
201 * After opening a database in read-write mode, the client should
202 * check if an upgrade is needed (notmuch_database_needs_upgrade) and
203 * if so, upgrade with this function before making any modifications.
205 * The optional progress_notify callback can be used by the caller to
206 * provide progress indication to the user. If non-NULL it will be
207 * called periodically with 'progress' as a floating-point value in
208 * the range of [0.0 .. 1.0] indicating the progress made so far in
209 * the upgrade process.
212 notmuch_database_upgrade (notmuch_database_t *database,
213 void (*progress_notify) (void *closure,
217 /* Retrieve a directory object from the database for 'path'.
219 * Here, 'path' should be a path relative to the path of 'database'
220 * (see notmuch_database_get_path), or else should be an absolute path
221 * with initial components that match the path of 'database'.
223 notmuch_directory_t *
224 notmuch_database_get_directory (notmuch_database_t *database,
227 /* Add a new message to the given notmuch database.
229 * Here,'filename' should be a path relative to the path of
230 * 'database' (see notmuch_database_get_path), or else should be an
231 * absolute filename with initial components that match the path of
234 * The file should be a single mail message (not a multi-message mbox)
235 * that is expected to remain at its current location, (since the
236 * notmuch database will reference the filename, and will not copy the
237 * entire contents of the file.
239 * If 'message' is not NULL, then, on successful return '*message'
240 * will be initialized to a message object that can be used for things
241 * such as adding tags to the just-added message. The user should call
242 * notmuch_message_destroy when done with the message. On any failure
243 * '*message' will be set to NULL.
247 * NOTMUCH_STATUS_SUCCESS: Message successfully added to database.
249 * NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID: Message has the same message
250 * ID as another message already in the database. The new filename
251 * was successfully added to the message in the database.
253 * NOTMUCH_STATUS_FILE_ERROR: an error occurred trying to open the
254 * file, (such as permission denied, or file not found,
255 * etc.). Nothing added to the database.
257 * NOTMUCH_STATUS_FILE_NOT_EMAIL: the contents of filename don't look
258 * like an email message. Nothing added to the database.
260 * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
261 * mode so no message can be added.
264 notmuch_database_add_message (notmuch_database_t *database,
265 const char *filename,
266 notmuch_message_t **message);
268 /* Remove a message from the given notmuch database.
270 * Note that only this particular filename association is removed from
271 * the database. If the same message (as determined by the message ID)
272 * is still available via other filenames, then the message will
273 * persist in the database for those filenames. When the last filename
274 * is removed for a particular message, the database content for that
275 * message will be entirely removed.
279 * NOTMUCH_STATUS_SUCCESS: The last filename was removed and the
280 * message was removed from the database.
282 * NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID: This filename was removed but
283 * the message persists in the database with at least one other
286 * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
287 * mode so no message can be removed.
290 notmuch_database_remove_message (notmuch_database_t *database,
291 const char *filename);
293 /* Find a message with the given message_id.
295 * If the database contains a message with the given message_id, then
296 * a new notmuch_message_t object is returned. The caller should call
297 * notmuch_message_destroy when done with the message.
299 * If no message is found with the given message_id or if an
300 * out-of-memory situation occurs, this function returns NULL.
303 notmuch_database_find_message (notmuch_database_t *database,
304 const char *message_id);
306 /* Return a list of all tags found in the database.
308 * This function creates a list of all tags found in the database. The
309 * resulting list contains all tags from all messages found in the database.
311 * On error this function returns NULL.
314 notmuch_database_get_all_tags (notmuch_database_t *db);
316 /* Create a new query for 'database'.
318 * Here, 'database' should be an open database, (see
319 * notmuch_database_open and notmuch_database_create).
321 * For the query string, we'll document the syntax here more
322 * completely in the future, but it's likely to be a specialized
323 * version of the general Xapian query syntax:
325 * http://xapian.org/docs/queryparser.html
327 * As a special case, passing a length-zero string, (that is ""), will
328 * result in a query that returns all messages in the database.
330 * See notmuch_query_set_sort for controlling the order of results and
331 * notmuch_query_search to actually execute the query.
333 * User should call notmuch_query_destroy when finished with this
336 * Will return NULL if insufficient memory is available.
339 notmuch_query_create (notmuch_database_t *database,
340 const char *query_string);
342 /* Sort values for notmuch_query_set_sort */
344 NOTMUCH_SORT_OLDEST_FIRST,
345 NOTMUCH_SORT_NEWEST_FIRST,
346 NOTMUCH_SORT_MESSAGE_ID
349 /* Specify the sorting desired for this query. */
351 notmuch_query_set_sort (notmuch_query_t *query, notmuch_sort_t sort);
353 /* Execute a query for threads, returning a notmuch_threads_t object
354 * which can be used to iterate over the results. The returned threads
355 * object is owned by the query and as such, will only be valid until
356 * notmuch_query_destroy.
358 * Typical usage might be:
360 * notmuch_query_t *query;
361 * notmuch_threads_t *threads;
362 * notmuch_thread_t *thread;
364 * query = notmuch_query_create (database, query_string);
366 * for (threads = notmuch_query_search_threads (query);
367 * notmuch_threads_valid (threads);
368 * notmuch_threads_move_to_next (threads))
370 * thread = notmuch_threads_get (threads);
372 * notmuch_thread_destroy (thread);
375 * notmuch_query_destroy (query);
377 * Note: If you are finished with a thread before its containing
378 * query, you can call notmuch_thread_destroy to clean up some memory
379 * sooner (as in the above example). Otherwise, if your thread objects
380 * are long-lived, then you don't need to call notmuch_thread_destroy
381 * and all the memory will still be reclaimed when the query is
384 * Note that there's no explicit destructor needed for the
385 * notmuch_threads_t object. (For consistency, we do provide a
386 * notmuch_threads_destroy function, but there's no good reason
387 * to call it if the query is about to be destroyed).
390 notmuch_query_search_threads (notmuch_query_t *query);
392 /* Execute a query for messages, returning a notmuch_messages_t object
393 * which can be used to iterate over the results. The returned
394 * messages object is owned by the query and as such, will only be
395 * valid until notmuch_query_destroy.
397 * Typical usage might be:
399 * notmuch_query_t *query;
400 * notmuch_messages_t *messages;
401 * notmuch_message_t *message;
403 * query = notmuch_query_create (database, query_string);
405 * for (messages = notmuch_query_search_messages (query);
406 * notmuch_messages_valid (messages);
407 * notmuch_messages_move_to_next (messages))
409 * message = notmuch_messages_get (messages);
411 * notmuch_message_destroy (message);
414 * notmuch_query_destroy (query);
416 * Note: If you are finished with a message before its containing
417 * query, you can call notmuch_message_destroy to clean up some memory
418 * sooner (as in the above example). Otherwise, if your message
419 * objects are long-lived, then you don't need to call
420 * notmuch_message_destroy and all the memory will still be reclaimed
421 * when the query is destroyed.
423 * Note that there's no explicit destructor needed for the
424 * notmuch_messages_t object. (For consistency, we do provide a
425 * notmuch_messages_destroy function, but there's no good
426 * reason to call it if the query is about to be destroyed).
429 notmuch_query_search_messages (notmuch_query_t *query);
431 /* Destroy a notmuch_query_t along with any associated resources.
433 * This will in turn destroy any notmuch_threads_t and
434 * notmuch_messages_t objects generated by this query, (and in
435 * turn any notmuch_thrad_t and notmuch_message_t objects generated
436 * from those results, etc.), if such objects haven't already been
440 notmuch_query_destroy (notmuch_query_t *query);
442 /* Is the given 'threads' iterator pointing at a valid thread.
444 * When this function returns TRUE, notmuch_threads_get will return a
445 * valid object. Whereas when this function returns FALSE,
446 * notmuch_threads_get will return NULL.
448 * See the documentation of notmuch_query_search_threads for example
449 * code showing how to iterate over a notmuch_threads_t object.
452 notmuch_threads_valid (notmuch_threads_t *threads);
454 /* Get the current thread from 'threads' as a notmuch_thread_t.
456 * Note: The returned thread belongs to 'threads' and has a lifetime
457 * identical to it (and the query to which it belongs).
459 * See the documentation of notmuch_query_search_threads for example
460 * code showing how to iterate over a notmuch_threads_t object.
462 * If an out-of-memory situation occurs, this function will return
466 notmuch_threads_get (notmuch_threads_t *threads);
468 /* Move the 'threads' iterator to the next thread.
470 * If 'threads' is already pointing at the last thread then the
471 * iterator will be moved to a point just beyond that last thread,
472 * (where notmuch_threads_valid will return FALSE and
473 * notmuch_threads_get will return NULL).
475 * See the documentation of notmuch_query_search_threads for example
476 * code showing how to iterate over a notmuch_threads_t object.
479 notmuch_threads_move_to_next (notmuch_threads_t *threads);
481 /* Destroy a notmuch_threads_t object.
483 * It's not strictly necessary to call this function. All memory from
484 * the notmuch_threads_t object will be reclaimed when the
485 * containg query object is destroyed.
488 notmuch_threads_destroy (notmuch_threads_t *threads);
490 /* Return an estimate of the number of messages matching a search
492 * This function performs a search and returns Xapian's best
493 * guess as to number of matching messages.
496 notmuch_query_count_messages (notmuch_query_t *query);
498 /* Get the thread ID of 'thread'.
500 * The returned string belongs to 'thread' and as such, should not be
501 * modified by the caller and will only be valid for as long as the
502 * thread is valid, (which is until notmuch_thread_destroy or until
503 * the query from which it derived is destroyed).
506 notmuch_thread_get_thread_id (notmuch_thread_t *thread);
508 /* Get the total number of messages in 'thread'.
510 * This count consists of all messages in the database belonging to
511 * this thread. Contrast with notmuch_thread_get_matched_messages() .
514 notmuch_thread_get_total_messages (notmuch_thread_t *thread);
516 /* Get a notmuch_messages_t iterator for the top-level messages in
519 * This iterator will not necessarily iterate over all of the messages
520 * in the thread. It will only iterate over the messages in the thread
521 * which are not replies to other messages in the thread.
523 * To iterate over all messages in the thread, the caller will need to
524 * iterate over the result of notmuch_message_get_replies for each
525 * top-level message (and do that recursively for the resulting
529 notmuch_thread_get_toplevel_messages (notmuch_thread_t *thread);
531 /* Get the number of messages in 'thread' that matched the search.
533 * This count includes only the messages in this thread that were
534 * matched by the search from which the thread was created. Contrast
535 * with notmuch_thread_get_total_messages() .
538 notmuch_thread_get_matched_messages (notmuch_thread_t *thread);
540 /* Get the authors of 'thread'
542 * The returned string is a comma-separated list of the names of the
543 * authors of mail messages in the query results that belong to this
546 * The returned string belongs to 'thread' and as such, should not be
547 * modified by the caller and will only be valid for as long as the
548 * thread is valid, (which is until notmuch_thread_destroy or until
549 * the query from which it derived is destroyed).
552 notmuch_thread_get_authors (notmuch_thread_t *thread);
554 /* Get the subject of 'thread'
556 * The subject is taken from the first message (according to the query
557 * order---see notmuch_query_set_sort) in the query results that
558 * belongs to this thread.
560 * The returned string belongs to 'thread' and as such, should not be
561 * modified by the caller and will only be valid for as long as the
562 * thread is valid, (which is until notmuch_thread_destroy or until
563 * the query from which it derived is destroyed).
566 notmuch_thread_get_subject (notmuch_thread_t *thread);
568 /* Get the date of the oldest message in 'thread' as a time_t value.
571 notmuch_thread_get_oldest_date (notmuch_thread_t *thread);
573 /* Get the date of the oldest message in 'thread' as a time_t value.
576 notmuch_thread_get_newest_date (notmuch_thread_t *thread);
578 /* Get the tags for 'thread', returning a notmuch_tags_t object which
579 * can be used to iterate over all tags.
581 * Note: In the Notmuch database, tags are stored on individual
582 * messages, not on threads. So the tags returned here will be all
583 * tags of the messages which matched the search and which belong to
586 * The tags object is owned by the thread and as such, will only be
587 * valid for as long as the thread is valid, (for example, until
588 * notmuch_thread_destroy or until the query from which it derived is
591 * Typical usage might be:
593 * notmuch_thread_t *thread;
594 * notmuch_tags_t *tags;
597 * thread = notmuch_threads_get (threads);
599 * for (tags = notmuch_thread_get_tags (thread);
600 * notmuch_tags_valid (tags);
601 * notmuch_result_move_to_next (tags))
603 * tag = notmuch_tags_get (tags);
607 * notmuch_thread_destroy (thread);
609 * Note that there's no explicit destructor needed for the
610 * notmuch_tags_t object. (For consistency, we do provide a
611 * notmuch_tags_destroy function, but there's no good reason to call
612 * it if the message is about to be destroyed).
615 notmuch_thread_get_tags (notmuch_thread_t *thread);
617 /* Destroy a notmuch_thread_t object. */
619 notmuch_thread_destroy (notmuch_thread_t *thread);
621 /* Is the given 'messages' iterator pointing at a valid message.
623 * When this function returns TRUE, notmuch_messages_get will return a
624 * valid object. Whereas when this function returns FALSE,
625 * notmuch_messages_get will return NULL.
627 * See the documentation of notmuch_query_search_messages for example
628 * code showing how to iterate over a notmuch_messages_t object.
631 notmuch_messages_valid (notmuch_messages_t *messages);
633 /* Get the current message from 'messages' as a notmuch_message_t.
635 * Note: The returned message belongs to 'messages' and has a lifetime
636 * identical to it (and the query to which it belongs).
638 * See the documentation of notmuch_query_search_messages for example
639 * code showing how to iterate over a notmuch_messages_t object.
641 * If an out-of-memory situation occurs, this function will return
645 notmuch_messages_get (notmuch_messages_t *messages);
647 /* Move the 'messages' iterator to the next message.
649 * If 'messages' is already pointing at the last message then the
650 * iterator will be moved to a point just beyond that last message,
651 * (where notmuch_messages_valid will return FALSE and
652 * notmuch_messages_get will return NULL).
654 * See the documentation of notmuch_query_search_messages for example
655 * code showing how to iterate over a notmuch_messages_t object.
658 notmuch_messages_move_to_next (notmuch_messages_t *messages);
660 /* Destroy a notmuch_messages_t object.
662 * It's not strictly necessary to call this function. All memory from
663 * the notmuch_messages_t object will be reclaimed when the containing
664 * query object is destroyed.
667 notmuch_messages_destroy (notmuch_messages_t *messages);
669 /* Return a list of tags from all messages.
671 * The resulting list is guaranteed not to contain duplicated tags.
673 * WARNING: You can no longer iterate over messages after calling this
674 * function, because the iterator will point at the end of the list.
675 * We do not have a function to reset the iterator yet and the only
676 * way how you can iterate over the list again is to recreate the
679 * The function returns NULL on error.
682 notmuch_messages_collect_tags (notmuch_messages_t *messages);
684 /* Get the message ID of 'message'.
686 * The returned string belongs to 'message' and as such, should not be
687 * modified by the caller and will only be valid for as long as the
688 * message is valid, (which is until the query from which it derived
691 * This function will not return NULL since Notmuch ensures that every
692 * message has a unique message ID, (Notmuch will generate an ID for a
693 * message if the original file does not contain one).
696 notmuch_message_get_message_id (notmuch_message_t *message);
698 /* Get the thread ID of 'message'.
700 * The returned string belongs to 'message' and as such, should not be
701 * modified by the caller and will only be valid for as long as the
702 * message is valid, (for example, until the user calls
703 * notmuch_message_destroy on 'message' or until a query from which it
704 * derived is destroyed).
706 * This function will not return NULL since Notmuch ensures that every
707 * message belongs to a single thread.
710 notmuch_message_get_thread_id (notmuch_message_t *message);
712 /* Get a notmuch_messages_t iterator for all of the replies to
715 * Note: This call only makes sense if 'message' was ultimately
716 * obtained from a notmuch_thread_t object, (such as by coming
717 * directly from the result of calling notmuch_thread_get_
718 * toplevel_messages or by any number of subsequent
719 * calls to notmuch_message_get_replies).
721 * If 'message' was obtained through some non-thread means, (such as
722 * by a call to notmuch_query_search_messages), then this function
725 * If there are no replies to 'message', this function will return
726 * NULL. (Note that notmuch_messages_valid will accept that NULL
727 * value as legitimate, and simply return FALSE for it.)
730 notmuch_message_get_replies (notmuch_message_t *message);
732 /* Get a filename for the email corresponding to 'message'.
734 * The returned filename is an absolute filename, (the initial
735 * component will match notmuch_database_get_path() ).
737 * The returned string belongs to the message so should not be
738 * modified or freed by the caller (nor should it be referenced after
739 * the message is destroyed).
741 * Note: If this message corresponds to multiple files in the mail
742 * store, (that is, multiple files contain identical message IDs),
743 * this function will arbitrarily return a single one of those
747 notmuch_message_get_filename (notmuch_message_t *message);
750 typedef enum _notmuch_message_flag {
751 NOTMUCH_MESSAGE_FLAG_MATCH,
752 } notmuch_message_flag_t;
754 /* Get a value of a flag for the email corresponding to 'message'. */
756 notmuch_message_get_flag (notmuch_message_t *message,
757 notmuch_message_flag_t flag);
759 /* Set a value of a flag for the email corresponding to 'message'. */
761 notmuch_message_set_flag (notmuch_message_t *message,
762 notmuch_message_flag_t flag, notmuch_bool_t value);
764 /* Get the date of 'message' as a time_t value.
766 * For the original textual representation of the Date header from the
767 * message call notmuch_message_get_header() with a header value of
770 notmuch_message_get_date (notmuch_message_t *message);
772 /* Get the value of the specified header from 'message'.
774 * The value will be read from the actual message file, not from the
775 * notmuch database. The header name is case insensitive.
777 * The returned string belongs to the message so should not be
778 * modified or freed by the caller (nor should it be referenced after
779 * the message is destroyed).
781 * Returns an empty string ("") if the message does not contain a
782 * header line matching 'header'. Returns NULL if any error occurs.
785 notmuch_message_get_header (notmuch_message_t *message, const char *header);
787 /* Get the tags for 'message', returning a notmuch_tags_t object which
788 * can be used to iterate over all tags.
790 * The tags object is owned by the message and as such, will only be
791 * valid for as long as the message is valid, (which is until the
792 * query from which it derived is destroyed).
794 * Typical usage might be:
796 * notmuch_message_t *message;
797 * notmuch_tags_t *tags;
800 * message = notmuch_database_find_message (database, message_id);
802 * for (tags = notmuch_message_get_tags (message);
803 * notmuch_tags_valid (tags);
804 * notmuch_result_move_to_next (tags))
806 * tag = notmuch_tags_get (tags);
810 * notmuch_message_destroy (message);
812 * Note that there's no explicit destructor needed for the
813 * notmuch_tags_t object. (For consistency, we do provide a
814 * notmuch_tags_destroy function, but there's no good reason to call
815 * it if the message is about to be destroyed).
818 notmuch_message_get_tags (notmuch_message_t *message);
820 /* The longest possible tag value. */
821 #define NOTMUCH_TAG_MAX 200
823 /* Add a tag to the given message.
827 * NOTMUCH_STATUS_SUCCESS: Tag successfully added to message
829 * NOTMUCH_STATUS_NULL_POINTER: The 'tag' argument is NULL
831 * NOTMUCH_STATUS_TAG_TOO_LONG: The length of 'tag' is too long
832 * (exceeds NOTMUCH_TAG_MAX)
834 * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
835 * mode so message cannot be modified.
838 notmuch_message_add_tag (notmuch_message_t *message, const char *tag);
840 /* Remove a tag from the given message.
844 * NOTMUCH_STATUS_SUCCESS: Tag successfully removed from message
846 * NOTMUCH_STATUS_NULL_POINTER: The 'tag' argument is NULL
848 * NOTMUCH_STATUS_TAG_TOO_LONG: The length of 'tag' is too long
849 * (exceeds NOTMUCH_TAG_MAX)
851 * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
852 * mode so message cannot be modified.
855 notmuch_message_remove_tag (notmuch_message_t *message, const char *tag);
857 /* Remove all tags from the given message.
859 * See notmuch_message_freeze for an example showing how to safely
860 * replace tag values.
862 * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
863 * mode so message cannot be modified.
866 notmuch_message_remove_all_tags (notmuch_message_t *message);
868 /* Freeze the current state of 'message' within the database.
870 * This means that changes to the message state, (via
871 * notmuch_message_add_tag, notmuch_message_remove_tag, and
872 * notmuch_message_remove_all_tags), will not be committed to the
873 * database until the message is thawed with notmuch_message_thaw.
875 * Multiple calls to freeze/thaw are valid and these calls will
876 * "stack". That is there must be as many calls to thaw as to freeze
877 * before a message is actually thawed.
879 * The ability to do freeze/thaw allows for safe transactions to
880 * change tag values. For example, explicitly setting a message to
881 * have a given set of tags might look like this:
883 * notmuch_message_freeze (message);
885 * notmuch_message_remove_all_tags (message);
887 * for (i = 0; i < NUM_TAGS; i++)
888 * notmuch_message_add_tag (message, tags[i]);
890 * notmuch_message_thaw (message);
892 * With freeze/thaw used like this, the message in the database is
893 * guaranteed to have either the full set of original tag values, or
894 * the full set of new tag values, but nothing in between.
896 * Imagine the example above without freeze/thaw and the operation
897 * somehow getting interrupted. This could result in the message being
898 * left with no tags if the interruption happened after
899 * notmuch_message_remove_all_tags but before notmuch_message_add_tag.
903 * NOTMUCH_STATUS_SUCCESS: Message successfully frozen.
905 * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
906 * mode so message cannot be modified.
909 notmuch_message_freeze (notmuch_message_t *message);
911 /* Thaw the current 'message', synchronizing any changes that may have
912 * occurred while 'message' was frozen into the notmuch database.
914 * See notmuch_message_freeze for an example of how to use this
915 * function to safely provide tag changes.
917 * Multiple calls to freeze/thaw are valid and these calls with
918 * "stack". That is there must be as many calls to thaw as to freeze
919 * before a message is actually thawed.
923 * NOTMUCH_STATUS_SUCCESS: Message successfully thawed, (or at least
924 * its frozen count has successfully been reduced by 1).
926 * NOTMUCH_STATUS_UNBALANCE_FREEZE_THAW: An attempt was made to thaw
927 * an unfrozen message. That is, there have been an unbalanced
928 * number of calls to notmuch_message_freeze and
929 * notmuch_message_thaw.
932 notmuch_message_thaw (notmuch_message_t *message);
934 /* Destroy a notmuch_message_t object.
936 * It can be useful to call this function in the case of a single
937 * query object with many messages in the result, (such as iterating
938 * over the entire database). Otherwise, it's fine to never call this
939 * function and there will still be no memory leaks. (The memory from
940 * the messages get reclaimed when the containing query is destroyed.)
943 notmuch_message_destroy (notmuch_message_t *message);
945 /* Is the given 'tags' iterator pointing at a valid tag.
947 * When this function returns TRUE, notmuch_tags_get will return a
948 * valid string. Whereas when this function returns FALSE,
949 * notmuch_tags_get will return NULL.
951 * See the documentation of notmuch_message_get_tags for example code
952 * showing how to iterate over a notmuch_tags_t object.
955 notmuch_tags_valid (notmuch_tags_t *tags);
957 /* Get the current tag from 'tags' as a string.
959 * Note: The returned string belongs to 'tags' and has a lifetime
960 * identical to it (and the query to which it ultimately belongs).
962 * See the documentation of notmuch_message_get_tags for example code
963 * showing how to iterate over a notmuch_tags_t object.
966 notmuch_tags_get (notmuch_tags_t *tags);
968 /* Move the 'tags' iterator to the next tag.
970 * If 'tags' is already pointing at the last tag then the iterator
971 * will be moved to a point just beyond that last tag, (where
972 * notmuch_tags_valid will return FALSE and notmuch_tags_get will
975 * See the documentation of notmuch_message_get_tags for example code
976 * showing how to iterate over a notmuch_tags_t object.
979 notmuch_tags_move_to_next (notmuch_tags_t *tags);
981 /* Destroy a notmuch_tags_t object.
983 * It's not strictly necessary to call this function. All memory from
984 * the notmuch_tags_t object will be reclaimed when the containing
985 * message or query objects are destroyed.
988 notmuch_tags_destroy (notmuch_tags_t *tags);
990 /* Store an mtime within the database for 'directory'.
992 * The 'directory' should be an object retrieved from the database
993 * with notmuch_database_get_directory for a particular path.
995 * The intention is for the caller to use the mtime to allow efficient
996 * identification of new messages to be added to the database. The
997 * recommended usage is as follows:
999 * o Read the mtime of a directory from the filesystem
1001 * o Call add_message for all mail files in the directory
1003 * o Call notmuch_directory_set_mtime with the mtime read from the
1006 * Then, when wanting to check for updates to the directory in the
1007 * future, the client can call notmuch_directory_get_mtime and know
1008 * that it only needs to add files if the mtime of the directory and
1009 * files are newer than the stored timestamp.
1011 * Note: The notmuch_directory_get_mtime function does not allow the
1012 * caller to distinguish a timestamp of 0 from a non-existent
1013 * timestamp. So don't store a timestamp of 0 unless you are
1014 * comfortable with that.
1018 * NOTMUCH_STATUS_SUCCESS: mtime successfully stored in database.
1020 * NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception
1021 * occurred, mtime not stored.
1023 * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
1024 * mode so directory mtime cannot be modified.
1027 notmuch_directory_set_mtime (notmuch_directory_t *directory,
1030 /* Get the mtime of a directory, (as previously stored with
1031 * notmuch_directory_set_mtime).
1033 * Returns 0 if no mtime has previously been stored for this
1036 notmuch_directory_get_mtime (notmuch_directory_t *directory);
1038 /* Get a notmuch_filenames_t iterator listing all the filenames of
1039 * messages in the database within the given directory.
1041 * The returned filenames will be the basename-entries only (not
1042 * complete paths). */
1043 notmuch_filenames_t *
1044 notmuch_directory_get_child_files (notmuch_directory_t *directory);
1046 /* Get a notmuch_filenams_t iterator listing all the filenames of
1047 * sub-directories in the database within the given directory.
1049 * The returned filenames will be the basename-entries only (not
1050 * complete paths). */
1051 notmuch_filenames_t *
1052 notmuch_directory_get_child_directories (notmuch_directory_t *directory);
1054 /* Destroy a notmuch_directory_t object. */
1056 notmuch_directory_destroy (notmuch_directory_t *directory);
1058 /* Is the given 'filenames' iterator pointing at a valid filename.
1060 * When this function returns TRUE, notmuch_filenames_get will return
1061 * a valid string. Whereas when this function returns FALSE,
1062 * notmuch_filenames_get will return NULL.
1064 * It is acceptable to pass NULL for 'filenames', in which case this
1065 * function will always return FALSE.
1068 notmuch_filenames_valid (notmuch_filenames_t *filenames);
1070 /* Get the current filename from 'filenames' as a string.
1072 * Note: The returned string belongs to 'filenames' and has a lifetime
1073 * identical to it (and the directory to which it ultimately belongs).
1075 * It is acceptable to pass NULL for 'filenames', in which case this
1076 * function will always return NULL.
1079 notmuch_filenames_get (notmuch_filenames_t *filenames);
1081 /* Move the 'filenames' iterator to the next filename.
1083 * If 'filenames' is already pointing at the last filename then the
1084 * iterator will be moved to a point just beyond that last filename,
1085 * (where notmuch_filenames_valid will return FALSE and
1086 * notmuch_filenames_get will return NULL).
1088 * It is acceptable to pass NULL for 'filenames', in which case this
1089 * function will do nothing.
1092 notmuch_filenames_move_to_next (notmuch_filenames_t *filenames);
1094 /* Destroy a notmuch_filenames_t object.
1096 * It's not strictly necessary to call this function. All memory from
1097 * the notmuch_filenames_t object will be reclaimed when the
1098 * containing directory object is destroyed.
1100 * It is acceptable to pass NULL for 'filenames', in which case this
1101 * function will do nothing.
1104 notmuch_filenames_destroy (notmuch_filenames_t *filenames);