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_XAPIAN_EXCEPTION: A Xapian exception occurred
62 * NOTMUCH_STATUS_FILE_ERROR: An error occurred trying to read or
63 * write to a file (this could be file not found, permission
66 * NOTMUCH_STATUS_FILE_NOT_EMAIL: A file was presented that doesn't
67 * appear to be an email message.
69 * NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID: A file contains a message ID
70 * that is identical to a message already in the database.
72 * NOTMUCH_STATUS_NULL_POINTER: The user erroneously passed a NULL
73 * pointer to a notmuch function.
75 * NOTMUCH_STATUS_TAG_TOO_LONG: A tag value is too long (exceeds
78 * NOTMUCH_STATUS_UNBALANCED_FREEZE_THAW: The notmuch_message_thaw
79 * function has been called more times than notmuch_message_freeze.
83 * NOTMUCH_STATUS_LAST_STATUS: Not an actual status value. Just a way
84 * to find out how many valid status values there are.
86 typedef enum _notmuch_status {
87 NOTMUCH_STATUS_SUCCESS = 0,
88 NOTMUCH_STATUS_OUT_OF_MEMORY,
89 NOTMUCH_STATUS_XAPIAN_EXCEPTION,
90 NOTMUCH_STATUS_FILE_ERROR,
91 NOTMUCH_STATUS_FILE_NOT_EMAIL,
92 NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID,
93 NOTMUCH_STATUS_NULL_POINTER,
94 NOTMUCH_STATUS_TAG_TOO_LONG,
95 NOTMUCH_STATUS_UNBALANCED_FREEZE_THAW,
97 NOTMUCH_STATUS_LAST_STATUS
100 /* Get a string representation of a notmuch_status_t value.
102 * The result is readonly.
105 notmuch_status_to_string (notmuch_status_t status);
107 /* Various opaque data types. For each notmuch_<foo>_t see the various
108 * notmuch_<foo> functions below. */
109 typedef struct _notmuch_database notmuch_database_t;
110 typedef struct _notmuch_query notmuch_query_t;
111 typedef struct _notmuch_thread_results notmuch_thread_results_t;
112 typedef struct _notmuch_thread notmuch_thread_t;
113 typedef struct _notmuch_message_results notmuch_message_results_t;
114 typedef struct _notmuch_message notmuch_message_t;
115 typedef struct _notmuch_tags notmuch_tags_t;
117 /* Lookup the default database path.
119 * This is the path that will be used by notmuch_database_create and
120 * notmuch_database_open if given a NULL path. Specifically it will be
121 * the value of the NOTMUCH_BASE environment variable if set,
122 * otherwise ${HOME}/mail
124 * Returns a newly allocated string which the caller should free()
125 * when finished with it.
128 notmuch_database_default_path (void);
130 /* Create a new, empty notmuch database located at 'path'.
132 * The path should be a top-level directory to a collection of
133 * plain-text email messages (one message per file). This call will
134 * create a new ".notmuch" directory within 'path' where notmuch will
137 * Passing a value of NULL for 'path' will cause notmuch to open the
138 * default database. The default database path can be specified by the
139 * NOTMUCH_BASE environment variable, and is equivalent to
140 * ${HOME}/mail if NOTMUCH_BASE is not set.
142 * After a successful call to notmuch_database_create, the returned
143 * database will be open so the caller should call
144 * notmuch_database_close when finished with it.
146 * The database will not yet have any data in it
147 * (notmuch_database_create itself is a very cheap function). Messages
148 * contained within 'path' can be added to the database by calling
149 * notmuch_database_add_message.
151 * In case of any failure, this function returns NULL, (after printing
152 * an error message on stderr).
155 notmuch_database_create (const char *path);
157 /* XXX: I think I'd like this to take an extra argument of
158 * notmuch_status_t* for returning a status value on failure. */
160 /* Open a an existing notmuch database located at 'path'.
162 * The database should have been created at some time in the past,
163 * (not necessarily by this process), by calling
164 * notmuch_database_create with 'path'.
166 * An existing notmuch database can be identified by the presence of a
167 * directory named ".notmuch" below 'path'.
169 * Passing a value of NULL for 'path' will cause notmuch to open the
170 * default database. The default database path can be specified by the
171 * NOTMUCH_BASE environment variable, and is equivalent to
172 * ${HOME}/mail if NOTMUCH_BASE is not set.
174 * The caller should call notmuch_database_close when finished with
177 * In case of any failure, this function returns NULL, (after printing
178 * an error message on stderr).
181 notmuch_database_open (const char *path);
183 /* Close the given notmuch database, freeing all associated
184 * resources. See notmuch_database_open. */
186 notmuch_database_close (notmuch_database_t *database);
188 /* Return the database path of the given database.
190 * The return value is a string owned by notmuch so should not be
191 * modified nor freed by the caller. */
193 notmuch_database_get_path (notmuch_database_t *database);
195 /* Store a timestamp within the database.
197 * The Notmuch database will not interpret this key nor the timestamp
198 * values at all. It will merely store them together and return the
199 * timestamp when notmuch_database_get_timestamp is called with the
200 * same value for 'key'.
202 * The intention is for the caller to use the timestamp to allow
203 * efficient identification of new messages to be added to the
204 * database. The recommended usage is as follows:
206 * o Read the mtime of a directory from the filesystem
208 * o Call add_message for all mail files in the directory
210 * o Call notmuch_database_set_timestamp with the path of the
211 * directory as 'key' and the originally read mtime as 'value'.
213 * Then, when wanting to check for updates to the directory in the
214 * future, the client can call notmuch_database_get_timestamp and know
215 * that it only needs to add files if the mtime of the directory and
216 * files are newer than the stored timestamp.
218 * Note: The notmuch_database_get_timestamp function does not allow
219 * the caller to distinguish a timestamp of 0 from a non-existent
220 * timestamp. So don't store a timestamp of 0 unless you are
221 * comfortable with that.
225 * NOTMUCH_STATUS_SUCCESS: Timestamp successfully stored in database.
227 * NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception
228 * occurred. Timestamp not stored.
231 notmuch_database_set_timestamp (notmuch_database_t *database,
232 const char *key, time_t timestamp);
234 /* Retrieve a timestamp from the database.
236 * Returns the timestamp value previously stored by calling
237 * notmuch_database_set_timestamp with the same value for 'key'.
239 * Returns 0 if no timestamp is stored for 'key' or if any error
240 * occurred querying the database.
243 notmuch_database_get_timestamp (notmuch_database_t *database,
246 /* Add a new message to the given notmuch database.
248 * Here,'filename' should be a path relative to the the path of
249 * 'database' (see notmuch_database_get_path), or else should be an
250 * absolute filename with initial components that match the path of
253 * The file should be a single mail message (not a multi-message mbox)
254 * that is expected to remain at its current location, (since the
255 * notmuch database will reference the filename, and will not copy the
256 * entire contents of the file.
258 * If 'message' is not NULL, then, on successful return '*message'
259 * will be initialized to a message object that can be used for things
260 * such as adding tags to the just-added message. The user should call
261 * notmuch_message_destroy when done with the message. On any failure
262 * '*message' will be set to NULL.
266 * NOTMUCH_STATUS_SUCCESS: Message successfully added to database.
268 * NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID: Message has the same message
269 * ID as another message already in the database. Nothing added
272 * NOTMUCH_STATUS_FILE_ERROR: an error occurred trying to open the
273 * file, (such as permission denied, or file not found,
274 * etc.). Nothing added to the database.
276 * NOTMUCH_STATUS_FILE_NOT_EMAIL: the contents of filename don't look
277 * like an email message. Nothing added to the database.
280 notmuch_database_add_message (notmuch_database_t *database,
281 const char *filename,
282 notmuch_message_t **message);
284 /* Find a message with the given messsage_id.
286 * If the database contains a message with the given message_id, then
287 * a new notmuch_message_t object is returned. The caller should call
288 * notmuch_message_destroy when done with the message.
290 * If no message is found with the given message_id or if an
291 * out-of-memory situation occurs, this function returns NULL.
294 notmuch_database_find_message (notmuch_database_t *database,
295 const char *message_id);
297 /* Create a new query for 'database'.
299 * Here, 'database' should be an open database, (see
300 * notmuch_database_open and notmuch_database_create).
302 * For the query string, we'll document the syntax here more
303 * completely in the future, but it's likely to be a specialized
304 * version of the general Xapian query syntax:
306 * http://xapian.org/docs/queryparser.html
308 * As a special case, passing a length-zero string, (that is ""), will
309 * result in a query that returns all messages in the database.
311 * See notmuch_query_set_sort for controlling the order of results and
312 * notmuch_query_search to actually execute the query.
314 * User should call notmuch_query_destroy when finished with this
317 * Will return NULL if insufficient memory is available.
320 notmuch_query_create (notmuch_database_t *database,
321 const char *query_string);
323 /* Sort values for notmuch_query_set_sort */
325 NOTMUCH_SORT_DATE_OLDEST_FIRST,
326 NOTMUCH_SORT_DATE_NEWEST_FIRST,
327 NOTMUCH_SORT_MESSAGE_ID
330 /* Specify the sorting desired for this query. */
332 notmuch_query_set_sort (notmuch_query_t *query, notmuch_sort_t sort);
334 /* Execute a query for threads, returning a notmuch_thread_results_t
335 * object which can be used to iterate over the results. The results
336 * object is owned by the query and as such, will only be valid until
337 * notmuch_query_destroy.
339 * Typical usage might be:
341 * notmuch_query_t *query;
342 * notmuch_thread_results_t *results;
343 * notmuch_thread_t *thread;
345 * query = notmuch_query_create (database, query_string);
347 * for (results = notmuch_query_search_threads (query);
348 * notmuch_thread_results_has_more (results);
349 * notmuch_thread_results_advance (results))
351 * thread = notmuch_thread_results_get (results);
353 * notmuch_thread_destroy (thread);
356 * notmuch_query_destroy (query);
358 * Note: If you are finished with a thread before its containing
359 * query, you can call notmuch_thread_destroy to clean up some memory
360 * sooner (as in the above example). Otherwise, if your thread objects
361 * are long-lived, then you don't need to call notmuch_thread_destroy
362 * and all the memory will still be reclaimed when the query is
365 * Note that there's no explicit destructor needed for the
366 * notmuch_thread_results_t object. (For consistency, we do provide a
367 * notmuch_thread_results_destroy function, but there's no good reason
368 * to call it if the query is about to be destroyed).
370 notmuch_thread_results_t *
371 notmuch_query_search_threads (notmuch_query_t *query);
373 /* Execute a query for messages, returning a notmuch_message_results_t
374 * object which can be used to iterate over the results. The results
375 * object is owned by the query and as such, will only be valid until
376 * notmuch_query_destroy.
378 * Typical usage might be:
380 * notmuch_query_t *query;
381 * notmuch_message_results_t *results;
382 * notmuch_message_t *message;
384 * query = notmuch_query_create (database, query_string);
386 * for (results = notmuch_query_search_messages (query);
387 * notmuch_message_results_has_more (results);
388 * notmuch_message_results_advance (results))
390 * message = notmuch_message_results_get (results);
392 * notmuch_message_destroy (message);
395 * notmuch_query_destroy (query);
397 * Note: If you are finished with a message before its containing
398 * query, you can call notmuch_message_destroy to clean up some memory
399 * sooner (as in the above example). Otherwise, if your message
400 * objects are long-lived, then you don't need to call
401 * notmuch_message_destroy and all the memory will still be reclaimed
402 * when the query is destroyed.
404 * Note that there's no explicit destructor needed for the
405 * notmuch_message_results_t object. (For consistency, we do provide a
406 * notmuch_message_results_destroy function, but there's no good
407 * reason to call it if the query is about to be destroyed).
409 notmuch_message_results_t *
410 notmuch_query_search_messages (notmuch_query_t *query);
412 /* Destroy a notmuch_query_t along with any associated resources.
414 * This will in turn destroy any notmuch_thread_results_t and
415 * notmuch_message_results_t objects generated by this query, (and in
416 * turn any notmuch_thrad_t and notmuch_message_t objects generated
417 * from those results, etc.), if such objects haven't already been
421 notmuch_query_destroy (notmuch_query_t *query);
423 /* Does the given notmuch_thread_results_t object contain any more
426 * When this function returns TRUE, notmuch_thread_results_get will
427 * return a valid object. Whereas when this function returns FALSE,
428 * notmuch_thread_results_get will return NULL.
430 * See the documentation of notmuch_query_search_threads for example
431 * code showing how to iterate over a notmuch_thread_results_t object.
434 notmuch_thread_results_has_more (notmuch_thread_results_t *results);
436 /* Get the current result from 'results' as a notmuch_thread_t.
438 * Note: The returned thread belongs to 'results' and has a lifetime
439 * identical to it (and the query to which it belongs).
441 * See the documentation of notmuch_query_search_threads for example
442 * code showing how to iterate over a notmuch_thread_results_t object.
444 * If an out-of-memory situation occurs, this function will return
448 notmuch_thread_results_get (notmuch_thread_results_t *results);
450 /* Advance the 'results' iterator to the next result.
452 * See the documentation of notmuch_query_search_threads for example
453 * code showing how to iterate over a notmuch_thread_results_t object.
456 notmuch_thread_results_advance (notmuch_thread_results_t *results);
458 /* Destroy a notmuch_thread_results_t object.
460 * It's not strictly necessary to call this function. All memory from
461 * the notmuch_thread_results_t object will be reclaimed when the
462 * containg query object is destroyed.
465 notmuch_thread_results_destroy (notmuch_thread_results_t *results);
467 /* Get the thread ID of 'thread'.
469 * The returned string belongs to 'thread' and as such, should not be
470 * modified by the caller and will only be valid for as long as the
471 * thread is valid, (which is until notmuch_thread_destroy or until
472 * the query from which it derived is destroyed).
475 notmuch_thread_get_thread_id (notmuch_thread_t *thread);
477 /* Get the subject of 'thread'
479 * The subject is taken from the first message (according to the query
480 * order---see notmuch_query_set_sort) in the query results that
481 * belongs to this thread.
483 * The returned string belongs to 'thread' and as such, should not be
484 * modified by the caller and will only be valid for as long as the
485 * thread is valid, (which is until notmuch_thread_destroy or until
486 * the query from which it derived is destroyed).
489 notmuch_thread_get_subject (notmuch_thread_t *thread);
491 /* Get the tags for 'thread', returning a notmuch_tags_t object which
492 * can be used to iterate over all tags.
494 * Note: In the Notmuch database, tags are stored on individual
495 * messages, not on threads. So the tags returned here will be all
496 * tags of the messages which matched the search and which belong to
499 * The tags object is owned by the thread and as such, will only be
500 * valid for as long as the thread is valid, (for example, until
501 * notmuch_thread_destroy or until the query from which it derived is
504 * Typical usage might be:
506 * notmuch_thread_t *thread;
507 * notmuch_tags_t *tags;
510 * thread = notmuch_thread_results_get (thread_results);
512 * for (tags = notmuch_thread_get_tags (thread);
513 * notmuch_tags_has_more (tags);
514 * notmuch_result_advance (tags))
516 * tag = notmuch_tags_get (tags);
520 * notmuch_thread_destroy (thread);
522 * Note that there's no explicit destructor needed for the
523 * notmuch_tags_t object. (For consistency, we do provide a
524 * notmuch_tags_destroy function, but there's no good reason to call
525 * it if the message is about to be destroyed).
528 notmuch_thread_get_tags (notmuch_thread_t *thread);
530 /* Destroy a notmuch_thread_t object. */
532 notmuch_thread_destroy (notmuch_thread_t *thread);
534 /* Does the given notmuch_message_results_t object contain any more
537 * When this function returns TRUE, notmuch_message_results_get will
538 * return a valid object. Whereas when this function returns FALSE,
539 * notmuch_message_results_get will return NULL.
541 * See the documentation of notmuch_query_search_messages for example
542 * code showing how to iterate over a notmuch_message_results_t
546 notmuch_message_results_has_more (notmuch_message_results_t *results);
548 /* Get the current result from 'results' as a notmuch_message_t.
550 * Note: The returned message belongs to 'results' and has a lifetime
551 * identical to it (and the query to which it belongs).
553 * See the documentation of notmuch_query_search_messages for example
554 * code showing how to iterate over a notmuch_message_results_t
557 * If an out-of-memory situation occurs, this function will return
561 notmuch_message_results_get (notmuch_message_results_t *results);
563 /* Advance the 'results' iterator to the next result.
565 * See the documentation of notmuch_query_search_messages for example
566 * code showing how to iterate over a notmuch_message_results_t
570 notmuch_message_results_advance (notmuch_message_results_t *results);
572 /* Destroy a notmuch_message_results_t object.
574 * It's not strictly necessary to call this function. All memory from
575 * the notmuch_message_results_t object will be reclaimed when the
576 * containg query object is destroyed.
579 notmuch_message_results_destroy (notmuch_message_results_t *results);
581 /* Get the message ID of 'message'.
583 * The returned string belongs to 'message' and as such, should not be
584 * modified by the caller and will only be valid for as long as the
585 * message is valid, (which is until the query from which it derived
588 * This function will not return NULL since Notmuch ensures that every
589 * message has a unique message ID, (Notmuch will generate an ID for a
590 * message if the original file does not contain one).
593 notmuch_message_get_message_id (notmuch_message_t *message);
595 /* Get the thread ID of 'message'.
597 * The returned string belongs to 'message' and as such, should not be
598 * modified by the caller and will only be valid for as long as the
599 * message is valid, (for example, until the user calls
600 * notmuch_message_destroy on 'message' or until a query from which it
601 * derived is destroyed).
603 * This function will not return NULL since Notmuch ensures that every
604 * message belongs to a single thread.
607 notmuch_message_get_thread_id (notmuch_message_t *message);
609 /* Get the filename for the email corresponding to 'message'.
611 * The returned filename is an absolute filename, (the initial
612 * component will match notmuch_database_get_path() ).
614 * The returned string belongs to the message so should not be
615 * modified or freed by the caller (nor should it be referenced after
616 * the message is destroyed). */
618 notmuch_message_get_filename (notmuch_message_t *message);
620 /* Get the size in bytes of the full header section of 'message'.
622 * This is useful in conjunction with notmuch_message_get_filename
623 * for separately parsing the message header and content.
625 * Returns 0 in the case of any error.
628 notmuch_message_get_header_size (notmuch_message_t *message);
630 /* Get the value of the specified header from 'message'.
632 * The value will be read from the actual message file, not from the
633 * notmuch database. The header name is case insensitive.
635 * The returned string belongs to the message so should not be
636 * modified or freed by the caller (nor should it be referenced after
637 * the message is destroyed).
639 * Returns NULL if the message does not contain a header line matching
640 * 'header' of if any error occurs.
643 notmuch_message_get_header (notmuch_message_t *message, const char *header);
645 /* Get the entire set of headers from an email message as a string.
647 * The value will be read from the actual message file, not from the
650 * The returned value is owned by the notmuch message and is valid
651 * only until the message is closed. The caller should copy it if
652 * needing to modify the value or to hold onto it for longer.
654 * Returns NULL in the case of any error.
657 notmuch_message_get_all_headers (notmuch_message_t *message);
659 /* Get the tags for 'message', returning a notmuch_tags_t object which
660 * can be used to iterate over all tags.
662 * The tags object is owned by the message and as such, will only be
663 * valid for as long as the message is valid, (which is until the
664 * query from which it derived is destroyed).
666 * Typical usage might be:
668 * notmuch_message_t *message;
669 * notmuch_tags_t *tags;
672 * message = notmuch_database_find_message (database, message_id);
674 * for (tags = notmuch_message_get_tags (message);
675 * notmuch_tags_has_more (tags);
676 * notmuch_result_advance (tags))
678 * tag = notmuch_tags_get (tags);
682 * notmuch_message_destroy (message);
684 * Note that there's no explicit destructor needed for the
685 * notmuch_tags_t object. (For consistency, we do provide a
686 * notmuch_tags_destroy function, but there's no good reason to call
687 * it if the message is about to be destroyed).
690 notmuch_message_get_tags (notmuch_message_t *message);
692 /* The longest possible tag value. */
693 #define NOTMUCH_TAG_MAX 200
695 /* Add a tag to the given message.
699 * NOTMUCH_STATUS_SUCCESS: Tag successfully added to message
701 * NOTMUCH_STATUS_NULL_POINTER: The 'tag' argument is NULL
703 * NOTMUCH_STATUS_TAG_TOO_LONG: The length of 'tag' is too long
704 * (exceeds NOTMUCH_TAG_MAX)
707 notmuch_message_add_tag (notmuch_message_t *message, const char *tag);
709 /* Remove a tag from the given message.
713 * NOTMUCH_STATUS_SUCCESS: Tag successfully removed from message
715 * NOTMUCH_STATUS_NULL_POINTER: The 'tag' argument is NULL
717 * NOTMUCH_STATUS_TAG_TOO_LONG: The length of 'tag' is too long
718 * (exceeds NOTMUCH_TAG_MAX)
721 notmuch_message_remove_tag (notmuch_message_t *message, const char *tag);
723 /* Remove all tags from the given message.
725 * See notmuch_message_freeze for an example showing how to safely
726 * replace tag values.
729 notmuch_message_remove_all_tags (notmuch_message_t *message);
731 /* Freeze the current state of 'message' within the database.
733 * This means that changes to the message state, (via
734 * notmuch_message_add_tag, notmuch_message_remove_tag, and
735 * notmuch_message_remove_all_tags), will not be committed to the
736 * database until the message is thawed with notmuch_message_thaw.
738 * Multiple calls to freeze/thaw are valid and these calls with
739 * "stack". That is there must be as many calls to thaw as to freeze
740 * before a message is actually thawed.
742 * The ability to do freeze/thaw allows for safe transactions to
743 * change tag values. For example, explicitly setting a message to
744 * have a given set of tags might look like this:
746 * notmuch_message_freeze (message);
748 * notmuch_message_remove_all_tags (message);
750 * for (i = 0; i < NUM_TAGS; i++)
751 * notmuch_message_add_tag (message, tags[i]);
753 * notmuch_message_thaw (message);
755 * With freeze/thaw used like this, the message in the database is
756 * guaranteed to have either the full set of original tag value, or
757 * the full set of new tag values, but nothing in between.
759 * Imagine the example above without freeze/thaw and the operation
760 * somehow getting interrupted. This could result in the message being
761 * left with no tags if the interruption happened after
762 * notmuch_message_remove_all_tags but before notmuch_message_add_tag.
765 notmuch_message_freeze (notmuch_message_t *message);
767 /* Thaw the current 'message', synchronizing any changes that may have
768 * occurred while 'message' was frozen into the notmuch database.
770 * See notmuch_message_freeze for an example of how to use this
771 * function to safely provide tag changes.
773 * Multiple calls to freeze/thaw are valid and these calls with
774 * "stack". That is there must be as many calls to thaw as to freeze
775 * before a message is actually thawed.
779 * NOTMUCH_STATUS_SUCCESS: Message successfully thawed, (or at least
780 * its frozen count has successfully been reduced by 1).
782 * NOTMUCH_STATUS_UNBALANCE_FREEZE_THAW: An attempt was made to thaw
783 * an unfrozen message. That is, there have been an unbalanced
784 * number of calls to notmuch_message_freeze and
785 * notmuch_message_thaw.
788 notmuch_message_thaw (notmuch_message_t *message);
790 /* Destroy a notmuch_message_t object.
792 * It can be useful to call this function in the case of a single
793 * query object with many messages in the result, (such as iterating
794 * over the entire database). Otherwise, it's fine to never call this
795 * function and there will still be no memory leaks. (The memory from
796 * the messages get reclaimed when the containing query is destroyed.)
799 notmuch_message_destroy (notmuch_message_t *message);
801 /* Does the given notmuch_tags_t object contain any more tags.
803 * When this function returns TRUE, notmuch_tags_get will return a
804 * valid string. Whereas when this function returns FALSE,
805 * notmuch_tags_get will return NULL.
807 * See the documentation of notmuch_message_get_tags for example code
808 * showing how to iterate over a notmuch_tags_t object.
811 notmuch_tags_has_more (notmuch_tags_t *tags);
813 /* Get the current tag from 'tags' as a string.
815 * Note: The returned string belongs to 'tags' and has a lifetime
816 * identical to it (and the query to which it utlimately belongs).
818 * See the documentation of notmuch_message_get_tags for example code
819 * showing how to iterate over a notmuch_tags_t object.
822 notmuch_tags_get (notmuch_tags_t *tags);
824 /* Advance the 'tags' iterator to the next tag.
826 * See the documentation of notmuch_message_get_tags for example code
827 * showing how to iterate over a notmuch_tags_t object.
830 notmuch_tags_advance (notmuch_tags_t *tags);
832 /* Destroy a notmuch_tags_t object.
834 * It's not strictly necessary to call this function. All memory from
835 * the notmuch_tags_t object will be reclaimed when the containg
836 * message or query objects are destroyed.
839 notmuch_tags_destroy (notmuch_tags_t *tags);