Merge tag '0.18.2_rc1'

[notmuch] / lib / notmuch.h

diff --git a/lib/notmuch.h b/lib/notmuch.h
index 350bed8bdbba956da7114bf969dfdcde513b5b8e..dae041640fdb2abb9d0a53e4d69540d2bdbf6054 100644 (file)
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -159,6 +159,10 @@ typedef enum _notmuch_status {
      * The operation is not supported.
      */
     NOTMUCH_STATUS_UNSUPPORTED_OPERATION,
+    /**
+     * The operation requires a database upgrade.
+     */
+    NOTMUCH_STATUS_UPGRADE_REQUIRED,
     /**
      * Not an actual status value. Just a way to find out how many
      * valid status values there are.
@@ -277,7 +281,7 @@ notmuch_database_open (const char *path,
                       notmuch_database_t **database);
 
 /**
- * Close the given notmuch database.
+ * Commit changes and close the given notmuch database.
  *
  * After notmuch_database_close has been called, calls to other
  * functions on objects derived from this database may either behave
@@ -287,8 +291,23 @@ notmuch_database_open (const char *path,
  *
  * notmuch_database_close can be called multiple times.  Later calls
  * have no effect.
+ *
+ * For writable databases, notmuch_database_close commits all changes
+ * to disk before closing the database.  If the caller is currently in
+ * an atomic section (there was a notmuch_database_begin_atomic
+ * without a matching notmuch_database_end_atomic), this will discard
+ * changes made in that atomic section (but still commit changes made
+ * prior to entering the atomic section).
+ *
+ * Return value:
+ *
+ * NOTMUCH_STATUS_SUCCESS: Successfully closed the database.
+ *
+ * NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception occurred; the
+ *     database has been closed but there are no guarantees the
+ *     changes to the database, if any, have been flushed to disk.
  */
-void
+notmuch_status_t
 notmuch_database_close (notmuch_database_t *database);
 
 /**
@@ -317,8 +336,11 @@ notmuch_database_compact (const char* path,
 /**
  * Destroy the notmuch database, closing it if necessary and freeing
  * all associated resources.
+ *
+ * Return value as in notmuch_database_close if the database was open;
+ * notmuch_database_destroy itself has no failure modes.
  */
-void
+notmuch_status_t
 notmuch_database_destroy (notmuch_database_t *database);
 
 /**
@@ -337,22 +359,27 @@ unsigned int
 notmuch_database_get_version (notmuch_database_t *database);
 
 /**
- * Does this database need to be upgraded before writing to it?
+ * Can the database be upgraded to a newer database version?
  *
- * If this function returns TRUE then no functions that modify the
- * database (notmuch_database_add_message, notmuch_message_add_tag,
- * notmuch_directory_set_mtime, etc.) will work unless the function
- * notmuch_database_upgrade is called successfully first.
+ * If this function returns TRUE, then the caller may call
+ * notmuch_database_upgrade to upgrade the database.  If the caller
+ * does not upgrade an out-of-date database, then some functions may
+ * fail with NOTMUCH_STATUS_UPGRADE_REQUIRED.  This always returns
+ * FALSE for a read-only database because there's no way to upgrade a
+ * read-only database.
  */
 notmuch_bool_t
 notmuch_database_needs_upgrade (notmuch_database_t *database);
 
 /**
- * Upgrade the current database.
+ * Upgrade the current database to the latest supported version.
  *
- * After opening a database in read-write mode, the client should
- * check if an upgrade is needed (notmuch_database_needs_upgrade) and
- * if so, upgrade with this function before making any modifications.
+ * This ensures that all current notmuch functionality will be
+ * available on the database.  After opening a database in read-write
+ * mode, it is recommended that clients check if an upgrade is needed
+ * (notmuch_database_needs_upgrade) and if so, upgrade with this
+ * function before making any modifications.  If
+ * notmuch_database_needs_upgrade returns FALSE, this will be a no-op.
  *
  * The optional progress_notify callback can be used by the caller to
  * provide progress indication to the user. If non-NULL it will be
@@ -427,6 +454,9 @@ notmuch_database_end_atomic (notmuch_database_t *notmuch);
  *
  * NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception occurred;
  *     directory not retrieved.
+ *
+ * NOTMUCH_STATUS_UPGRADE_REQUIRED: The caller must upgrade the
+ *     database to use this function.
  */
 notmuch_status_t
 notmuch_database_get_directory (notmuch_database_t *database,
@@ -479,6 +509,9 @@ notmuch_database_get_directory (notmuch_database_t *database,
  *
  * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
  *     mode so no message can be added.
+ *
+ * NOTMUCH_STATUS_UPGRADE_REQUIRED: The caller must upgrade the
+ *     database to use this function.
  */
 notmuch_status_t
 notmuch_database_add_message (notmuch_database_t *database,
@@ -509,6 +542,9 @@ notmuch_database_add_message (notmuch_database_t *database,
  *
  * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
  *     mode so no message can be removed.
+ *
+ * NOTMUCH_STATUS_UPGRADE_REQUIRED: The caller must upgrade the
+ *     database to use this function.
  */
 notmuch_status_t
 notmuch_database_remove_message (notmuch_database_t *database,
@@ -564,6 +600,9 @@ notmuch_database_find_message (notmuch_database_t *database,
  * NOTMUCH_STATUS_OUT_OF_MEMORY: Out of memory, creating the message object
  *
  * NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception occurred
+ *
+ * NOTMUCH_STATUS_UPGRADE_REQUIRED: The caller must upgrade the
+ *     database to use this function.
  */
 notmuch_status_t
 notmuch_database_find_message_by_filename (notmuch_database_t *notmuch,
@@ -941,6 +980,10 @@ notmuch_thread_get_matched_messages (notmuch_thread_t *thread);
  * authors of mail messages in the query results that belong to this
  * thread.
  *
+ * The string contains authors of messages matching the query first, then
+ * non-matched authors (with the two groups separated by '|'). Within
+ * each group, authors are ordered by date.
+ *
  * The returned string belongs to 'thread' and as such, should not be
  * modified by the caller and will only be valid for as long as the
  * thread is valid, (which is until notmuch_thread_destroy or until