Implement Thread() and Threads()

Most of Thread() is implemented now and all of Threads(). Reorganized the
source somewhat and various minor fixes throughout.

cnotmuch/database.py

@@ -1,6 +1,8 @@
 import ctypes, os
 from ctypes import c_int, c_char_p, c_void_p, c_uint, c_uint64, c_bool, byref
 from cnotmuch.globals import nmlib, STATUS, NotmuchError, Enum
+from cnotmuch.thread import Thread, Threads
+from cnotmuch.tags import Tags
 import logging
 from datetime import date
 
@@ -355,6 +357,10 @@ class Query(object):
     A query selects and filters a subset of messages from the notmuch
     database we derive from.
 
+    Query() provides an instance attribute :attr:`sort`, which
+    contains the sort order (if specified via :meth:`set_sort`) or
+    `None`.
+
     Technically, it wraps the underlying *notmuch_query_t* struct.
 
     .. note:: Do remember that as soon as we tear down this object,
@@ -371,6 +377,10 @@ class Query(object):
     _create = nmlib.notmuch_query_create
     _create.restype = c_void_p
 
+    """notmuch_query_search_threads"""
+    _search_threads = nmlib.notmuch_query_search_threads
+    _search_threads.restype = c_void_p
+
     """notmuch_query_search_messages"""
     _search_messages = nmlib.notmuch_query_search_messages
     _search_messages.restype = c_void_p
@@ -389,6 +399,7 @@ class Query(object):
         """
         self._db = None
         self._query = None
+        self.sort = None
         self.create(db, querystr)
 
     def create(self, db, querystr):
@@ -432,8 +443,35 @@ class Query(object):
         if self._query is None:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
+        self.sort = sort
         nmlib.notmuch_query_set_sort(self._query, sort)
 
+    def search_threads(self):
+        """Execute a query for threads
+
+        Execute a query for threads, returning a :class:`Threads` iterator.
+        The returned threads are owned by the query and as such, will only be 
+        valid until the Query is deleted.
+
+        Technically, it wraps the underlying
+        *notmuch_query_search_threads* function.
+
+        :returns: :class:`Threads`
+        :exception: :exc:`NotmuchError`
+
+                      * STATUS.NOT_INITIALIZED if query is not inited
+                      * STATUS.NULL_POINTER if search_messages failed 
+        """
+        if self._query is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)            
+
+        threads_p = Query._search_threads(self._query)
+
+        if threads_p is None:
+            NotmuchError(STATUS.NULL_POINTER)
+
+        return Threads(threads_p,self)
+
     def search_messages(self):
         """Filter messages according to the query and return
         :class:`Messages` in the defined sort order
@@ -483,115 +521,6 @@ class Query(object):
             logging.debug("Freeing the Query now")
             nmlib.notmuch_query_destroy (self._query)
 
-#------------------------------------------------------------------------------
-class Tags(object):
-    """Represents a list of notmuch tags
-
-    This object provides an iterator over a list of notmuch tags. Do
-    note that the underlying library only provides a one-time iterator
-    (it cannot reset the iterator to the start). Thus iterating over
-    the function will "exhaust" the list of tags, and a subsequent
-    iteration attempt will raise a :exc:`NotmuchError`
-    STATUS.NOT_INITIALIZED. Also note, that any function that uses
-    iteration (nearly all) will also exhaust the tags. So both::
-
-      for tag in tags: print tag 
-
-    as well as::
-
-       number_of_tags = len(tags)
-
-    and even a simple::
-
-       #str() iterates over all tags to construct a space separated list
-       print(str(tags))
-
-    will "exhaust" the Tags. If you need to re-iterate over a list of
-    tags you will need to retrieve a new :class:`Tags` object.
-    """
-
-    #notmuch_tags_get
-    _get = nmlib.notmuch_tags_get
-    _get.restype = c_char_p
-
-    def __init__(self, tags_p, parent=None):
-        """
-        :param tags_p: A pointer to an underlying *notmuch_tags_t*
-             structure. These are not publically exposed, so a user
-             will almost never instantiate a :class:`Tags` object
-             herself. They are usually handed back as a result,
-             e.g. in :meth:`Database.get_all_tags`.  *tags_p* must be
-             valid, we will raise an :exc:`NotmuchError`
-             (STATUS.NULL_POINTER) if it is `None`.
-        :type tags_p: :class:`ctypes.c_void_p`
-        :param parent: The parent object (ie :class:`Database` or 
-             :class:`Message` these tags are derived from, and saves a
-             reference to it, so we can automatically delete the db object
-             once all derived objects are dead.
-        :TODO: Make the iterator optionally work more than once by
-               cache the tags in the Python object(?)
-        """
-        if tags_p is None:
-            NotmuchError(STATUS.NULL_POINTER)
-
-        self._tags = tags_p
-        #save reference to parent object so we keep it alive
-        self._parent = parent
-        logging.debug("Inited Tags derived from %s" %(repr(parent)))
-    
-    def __iter__(self):
-        """ Make Tags an iterator """
-        return self
-
-    def next(self):
-        if self._tags is None:
-            raise NotmuchError(STATUS.NOT_INITIALIZED)
-
-        if not nmlib.notmuch_tags_valid(self._tags):
-            self._tags = None
-            raise StopIteration
-
-        tag = Tags._get (self._tags)
-        nmlib.notmuch_tags_move_to_next(self._tags)
-        return tag
-
-    def __len__(self):
-        """len(:class:`Tags`) returns the number of contained tags
-
-        .. note:: As this iterates over the tags, we will not be able
-               to iterate over them again (as in retrieve them)! If
-               the tags have been exhausted already, this will raise a
-               :exc:`NotmuchError` STATUS.NOT_INITIALIZED on
-               subsequent attempts.
-        """
-        if self._tags is None:
-            raise NotmuchError(STATUS.NOT_INITIALIZED)
-
-        i=0
-        while nmlib.notmuch_tags_valid(self._msgs):
-            nmlib.notmuch_tags_move_to_next(self._msgs)
-            i += 1
-        self._tags = None
-        return i
-
-    def __str__(self):
-        """The str() representation of Tags() is a space separated list of tags
-
-        .. note:: As this iterates over the tags, we will not be able
-               to iterate over them again (as in retrieve them)! If
-               the tags have been exhausted already, this will raise a
-               :exc:`NotmuchError` STATUS.NOT_INITIALIZED on
-               subsequent attempts.
-        """
-        return " ".join(self)
-
-    def __del__(self):
-        """Close and free the notmuch tags"""
-        if self._tags is not None:
-            logging.debug("Freeing the Tags now")
-            nmlib.notmuch_tags_destroy (self._tags)
-
-
 #------------------------------------------------------------------------------
 class Messages(object):
     """Represents a list of notmuch messages
@@ -721,6 +650,12 @@ class Messages(object):
                  if len(msgs) > 0:              #this 'exhausts' msgs
                      # next line raises NotmuchError(STATUS.NOT_INITIALIZED)!!!
                      for msg in msgs: print msg
+
+               Most of the time, using the
+               :meth:`Query.count_messages` is therefore more
+               appropriate (and much faster). While not guaranteeing
+               that it will return the exact same number than len(),
+               in my tests it effectively always did so.
         """
         if self._msgs is None:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
@@ -855,7 +790,7 @@ class Message(object):
         message call notmuch_message_get_header() with a header value of
         "date".
 
-        :returns: a time_t timestamp
+        :returns: A time_t timestamp.
         :rtype: c_unit64
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message 
                     is not initialized.
@@ -892,7 +827,7 @@ class Message(object):
         return header
 
     def get_filename(self):
-        """Return the file path of the message file
+        """Returns the file path of the message file
 
         :returns: Absolute file path & name of the message file
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message 
@@ -903,10 +838,9 @@ class Message(object):
         return Message._get_filename(self._msg)
 
     def get_tags(self):
-        """ Return the message tags
+        """Returns the message tags
 
-        :returns: Message tags
+        :returns: A :class:`Tags` iterator.
-        :rtype: :class:`Tags`
         :exception: :exc:`NotmuchError`
 
                       * STATUS.NOT_INITIALIZED if the message 
@@ -922,7 +856,7 @@ class Message(object):
         return Tags(tags_p, self)
 
     def add_tag(self, tag):
-        """Add a tag to the given message
+        """Adds a tag to the given message
 
         Adds a tag to the current message. The maximal tag length is defined in
         the notmuch library and is currently 200 bytes.

cnotmuch/notmuch.py

@@ -34,10 +34,8 @@ Many of its objects use python's logging module to log some output at DEBUG leve
     :class:`Message`, and :class:`Tags`.
 
 """
-import ctypes
+from database import Database, Query
-from ctypes import c_int, c_char_p
+from cnotmuch.globals import nmlib, STATUS, NotmuchError
-from database import Database,Tags,Query,Messages,Message,Tags
-from cnotmuch.globals import nmlib,STATUS,NotmuchError
 __LICENSE__="GPL v3+"
 __VERSION__='0.1.1'
 __AUTHOR__ ='Sebastian Spaeth <Sebastian@SSpaeth.de>'

cnotmuch/tags.py

@@ -0,0 +1,108 @@
+from ctypes import c_char_p
+from cnotmuch.globals import nmlib, STATUS, NotmuchError
+
+#------------------------------------------------------------------------------
+class Tags(object):
+    """Represents a list of notmuch tags
+
+    This object provides an iterator over a list of notmuch tags. Do
+    note that the underlying library only provides a one-time iterator
+    (it cannot reset the iterator to the start). Thus iterating over
+    the function will "exhaust" the list of tags, and a subsequent
+    iteration attempt will raise a :exc:`NotmuchError`
+    STATUS.NOT_INITIALIZED. Also note, that any function that uses
+    iteration (nearly all) will also exhaust the tags. So both::
+
+      for tag in tags: print tag 
+
+    as well as::
+
+       number_of_tags = len(tags)
+
+    and even a simple::
+
+       #str() iterates over all tags to construct a space separated list
+       print(str(tags))
+
+    will "exhaust" the Tags. If you need to re-iterate over a list of
+    tags you will need to retrieve a new :class:`Tags` object.
+    """
+
+    #notmuch_tags_get
+    _get = nmlib.notmuch_tags_get
+    _get.restype = c_char_p
+
+    def __init__(self, tags_p, parent=None):
+        """
+        :param tags_p: A pointer to an underlying *notmuch_tags_t*
+             structure. These are not publically exposed, so a user
+             will almost never instantiate a :class:`Tags` object
+             herself. They are usually handed back as a result,
+             e.g. in :meth:`Database.get_all_tags`.  *tags_p* must be
+             valid, we will raise an :exc:`NotmuchError`
+             (STATUS.NULL_POINTER) if it is `None`.
+        :type tags_p: :class:`ctypes.c_void_p`
+        :param parent: The parent object (ie :class:`Database` or 
+             :class:`Message` these tags are derived from, and saves a
+             reference to it, so we can automatically delete the db object
+             once all derived objects are dead.
+        :TODO: Make the iterator optionally work more than once by
+               cache the tags in the Python object(?)
+        """
+        if tags_p is None:
+            NotmuchError(STATUS.NULL_POINTER)
+
+        self._tags = tags_p
+        #save reference to parent object so we keep it alive
+        self._parent = parent
+    
+    def __iter__(self):
+        """ Make Tags an iterator """
+        return self
+
+    def next(self):
+        if self._tags is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+
+        if not nmlib.notmuch_tags_valid(self._tags):
+            self._tags = None
+            raise StopIteration
+
+        tag = Tags._get (self._tags)
+        nmlib.notmuch_tags_move_to_next(self._tags)
+        return tag
+
+    def __len__(self):
+        """len(:class:`Tags`) returns the number of contained tags
+
+        .. note:: As this iterates over the tags, we will not be able
+               to iterate over them again (as in retrieve them)! If
+               the tags have been exhausted already, this will raise a
+               :exc:`NotmuchError` STATUS.NOT_INITIALIZED on
+               subsequent attempts.
+        """
+        if self._tags is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+
+        i=0
+        while nmlib.notmuch_tags_valid(self._msgs):
+            nmlib.notmuch_tags_move_to_next(self._msgs)
+            i += 1
+        self._tags = None
+        return i
+
+    def __str__(self):
+        """The str() representation of Tags() is a space separated list of tags
+
+        .. note:: As this iterates over the tags, we will not be able
+               to iterate over them again (as in retrieve them)! If
+               the tags have been exhausted already, this will raise a
+               :exc:`NotmuchError` STATUS.NOT_INITIALIZED on
+               subsequent attempts.
+        """
+        return " ".join(self)
+
+    def __del__(self):
+        """Close and free the notmuch tags"""
+        if self._tags is not None:
+            nmlib.notmuch_tags_destroy (self._tags)

cnotmuch/thread.py

@@ -0,0 +1,319 @@
+from ctypes import c_char_p, c_void_p, c_uint64
+from cnotmuch.globals import nmlib, STATUS, NotmuchError, Enum
+from cnotmuch.tags import Tags
+from datetime import date
+
+#------------------------------------------------------------------------------
+class Threads(object):
+    """Represents a list of notmuch threads
+
+    This object provides an iterator over a list of notmuch threads
+    (Technically, it provides a wrapper for the underlying
+    *notmuch_threads_t* structure). Do note that the underlying
+    library only provides a one-time iterator (it cannot reset the
+    iterator to the start). Thus iterating over the function will
+    "exhaust" the list of threads, and a subsequent iteration attempt
+    will raise a :exc:`NotmuchError` STATUS.NOT_INITIALIZED. Also
+    note, that any function that uses iteration will also
+    exhaust the messages. So both::
+
+      for thread in threads: print thread
+
+    as well as::
+
+       number_of_msgs = len(threads)
+
+    will "exhaust" the threads. If you need to re-iterate over a list of
+    messages you will need to retrieve a new :class:`Threads` object.
+
+    Things are not as bad as it seems though, you can store and reuse
+    the single Thread objects as often as you want as long as you
+    keep the parent Threads object around. (Recall that due to
+    hierarchical memory allocation, all derived Threads objects will
+    be invalid when we delete the parent Threads() object, even if it
+    was already "exhausted".) So this works::
+
+      db   = Database()
+      threads = Query(db,'').search_threads() #get a Threads() object
+      threadlist = []
+      for thread in threads:
+         threadlist.append(thread)
+
+      # threads is "exhausted" now and even len(threads) will raise an 
+      # exception.
+      # However it will be kept around until all retrieved Thread() objects are
+      # also deleted. If you did e.g. an explicit del(threads) here, the 
+      # following lines would fail.
+      
+      # You can reiterate over *threadlist* however as often as you want. 
+      # It is simply a list with Thread objects.
+
+      print (threadlist[0].get_thread_id())
+      print (threadlist[1].get_thread_id())
+      print (threadlist[0].get_total_messages())
+    """
+
+    #notmuch_threads_get
+    _get = nmlib.notmuch_threads_get
+    _get.restype = c_void_p
+
+    def __init__(self, threads_p, parent=None):
+        """
+        :param threads_p:  A pointer to an underlying *notmuch_threads_t*
+             structure. These are not publically exposed, so a user
+             will almost never instantiate a :class:`Threads` object
+             herself. They are usually handed back as a result,
+             e.g. in :meth:`Query.search_threads`.  *threads_p* must be
+             valid, we will raise an :exc:`NotmuchError`
+             (STATUS.NULL_POINTER) if it is `None`.
+        :type threads_p: :class:`ctypes.c_void_p`
+        :param parent: The parent object
+             (ie :class:`Query`) these tags are derived from. It saves
+             a reference to it, so we can automatically delete the db
+             object once all derived objects are dead.
+        :TODO: Make the iterator work more than once and cache the tags in 
+               the Python object.(?)
+        """
+        if threads_p is None:
+            NotmuchError(STATUS.NULL_POINTER)
+
+        self._threads = threads_p
+        #store parent, so we keep them alive as long as self  is alive
+        self._parent = parent
+
+    def __iter__(self):
+        """ Make Threads an iterator """
+        return self
+
+    def next(self):
+        if self._threads is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+
+        if not nmlib.notmuch_threads_valid(self._threads):
+            self._threads = None
+            raise StopIteration
+
+        thread = Thread(Threads._get (self._threads), self)
+        nmlib.notmuch_threads_move_to_next(self._threads)
+        return thread
+
+    def __len__(self):
+        """len(:class:`Threads`) returns the number of contained Threads
+
+        .. note:: As this iterates over the threads, we will not be able to 
+               iterate over them again! So this will fail::
+
+                 #THIS FAILS
+                 threads = Database().create_query('').search_threads()
+                 if len(threads) > 0:              #this 'exhausts' threads
+                     # next line raises NotmuchError(STATUS.NOT_INITIALIZED)!!!
+                     for thread in threads: print thread
+        """
+        if self._threads is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+
+        i=0
+        # returns 'bool'. On out-of-memory it returns None
+        while nmlib.notmuch_threads_valid(self._threads):
+            nmlib.notmuch_threads_move_to_next(self._threads)
+            i += 1
+        # reset self._threads to mark as "exhausted"
+        self._threads = None
+        return i
+
+
+
+    def __del__(self):
+        """Close and free the notmuch Threads"""
+        if self._threads is not None:
+            nmlib.notmuch_messages_destroy (self._threads)
+
+#------------------------------------------------------------------------------
+class Thread(object):
+    """Represents a single message thread."""
+
+    """notmuch_thread_get_thread_id"""
+    _get_thread_id = nmlib.notmuch_thread_get_thread_id
+    _get_thread_id.restype = c_char_p
+
+    """notmuch_thread_get_authors"""
+    _get_authors = nmlib.notmuch_thread_get_authors
+    _get_authors.restype = c_char_p
+
+    """notmuch_thread_get_subject"""
+    _get_subject = nmlib.notmuch_thread_get_subject
+    _get_subject.restype = c_char_p
+
+    _get_newest_date = nmlib.notmuch_thread_get_newest_date
+    _get_newest_date.restype = c_uint64
+
+    _get_oldest_date = nmlib.notmuch_thread_get_oldest_date
+    _get_oldest_date.restype = c_uint64
+
+    """notmuch_thread_get_tags"""
+    _get_tags = nmlib.notmuch_thread_get_tags
+    _get_tags.restype = c_void_p
+
+    def __init__(self, thread_p, parent=None):
+        """
+        :param thread_p: A pointer to an internal notmuch_thread_t
+            Structure.  These are not publically exposed, so a user
+            will almost never instantiate a :class:`Thread` object
+            herself. They are usually handed back as a result,
+            e.g. when iterating through :class:`Threads`. *thread_p*
+            must be valid, we will raise an :exc:`NotmuchError`
+            (STATUS.NULL_POINTER) if it is `None`.
+
+        :param parent: A 'parent' object is passed which this message is
+              derived from. We save a reference to it, so we can
+              automatically delete the parent object once all derived
+              objects are dead.
+        """
+        if thread_p is None:
+            NotmuchError(STATUS.NULL_POINTER)
+        self._thread = thread_p
+        #keep reference to parent, so we keep it alive
+        self._parent = parent
+
+    def get_thread_id(self):
+        """Get the thread ID of 'thread'
+
+        The returned string belongs to 'thread' and will only be valid
+        for as long as the thread is valid.
+
+        :returns: String with a message ID
+        :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the thread 
+                    is not initialized.
+        """
+        if self._thread is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+        return Thread._get_thread_id(self._thread)
+
+    def get_total_messages(self):
+        """Get the total number of messages in 'thread'
+
+        :returns: The number of all messages in the database
+                  belonging to this thread. Contrast with
+                  :meth:`get_matched_messages`.
+        :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the thread 
+                    is not initialized.
+        """
+        if self._thread is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+        return nmlib.notmuch_thread_get_total_messages(self._thread)
+
+
+    ###TODO: notmuch_messages_t * notmuch_thread_get_toplevel_messages (notmuch_thread_t *thread);
+
+    def get_matched_messages(self):
+        """Returns the number of messages in 'thread' that matched the query
+
+        :returns: The number of all messages belonging to this thread that 
+                  matched the :class:`Query`from which this thread was created.
+                  Contrast with :meth:`get_total_messages`.
+        :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the thread 
+                    is not initialized.
+        """
+        if self._thread is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+        return nmlib.notmuch_thread_get_matched_messages(self._thread)
+
+    def get_authors(self):
+        """Returns the authors of 'thread'
+
+        The returned string is a comma-separated list of the names of the
+        authors of mail messages in the query results that belong to this
+        thread.
+
+        The returned string belongs to 'thread' and will only be valid for 
+        as long as this Thread() is not deleted.
+        """
+        if self._thread is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+        return Thread._get_authors(self._thread)
+
+    def get_subject(self):
+        """Returns the Subject of 'thread'
+
+        The returned string belongs to 'thread' and will only be valid for 
+        as long as this Thread() is not deleted.
+        """
+        if self._thread is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+        return Thread._get_subject(self._thread)
+
+    def get_newest_date(self):
+        """Returns time_t of the newest message date
+
+        :returns: A time_t timestamp.
+        :rtype: c_unit64
+        :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message 
+                    is not initialized.
+        """
+        if self._thread is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+        return Thread._get_newest_date(self._thread)
+
+    def get_oldest_date(self):
+        """Returns time_t of the oldest message date
+
+        :returns: A time_t timestamp.
+        :rtype: c_unit64
+        :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message 
+                    is not initialized.
+        """
+        if self._thread is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+        return Thread._get_oldest_date(self._thread)
+
+    def get_tags(self):
+        """ Returns the message tags
+
+        In the Notmuch database, tags are stored on individual
+        messages, not on threads. So the tags returned here will be all
+        tags of the messages which matched the search and which belong to
+        this thread.
+
+        The :class:`Tags` object is owned by the thread and as such, will only 
+        be valid for as long as this :class:`Thread` is valid (e.g. until the 
+        query from which it derived is explicitely deleted).
+
+        :returns: A :class:`Tags` iterator.
+        :exception: :exc:`NotmuchError`
+
+                      * STATUS.NOT_INITIALIZED if the thread 
+                        is not initialized.
+                      * STATUS.NULL_POINTER, on error
+        """
+        if self._thread is None:
+            raise NotmuchError(STATUS.NOT_INITIALIZED)
+
+        tags_p = Thread._get_tags(self._thread)
+        if tags_p == None:
+            raise NotmuchError(STATUS.NULL_POINTER)
+        return Tags(tags_p, self)
+ 
+    def __str__(self):
+        """A str(Thread()) is represented by a 1-line summary"""
+        thread = {}
+        thread['id'] = self.get_thread_id()
+
+        ###TODO: How do we find out the current sort order of Threads?
+        ###Add a "sort" attribute to the Threads() object?
+        #if (sort == NOTMUCH_SORT_OLDEST_FIRST)
+        #         date = notmuch_thread_get_oldest_date (thread);
+        #else
+        #         date = notmuch_thread_get_newest_date (thread);
+        thread['date'] = date.fromtimestamp(self.get_newest_date())
+        thread['matched'] = self.get_matched_messages()
+        thread['total'] = self.get_total_messages()
+        thread['authors'] = self.get_authors()
+        thread['subject'] = self.get_subject()
+        thread['tags'] = self.get_tags()
+
+        return "thread:%(id)s %(date)12s [%(matched)d/%(total)d] %(authors)s; %(subject)s (%(tags)s)" % (thread)
+
+    def __del__(self):
+        """Close and free the notmuch Thread"""
+        if self._thread is not None:
+            nmlib.notmuch_thread_destroy (self._thread)