-
-class Threads(Python3StringMixIn):
- """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:`NotInitializedError`. 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.argtypes = [NotmuchThreadsP]
- _get.restype = NotmuchThreadP
-
- 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:`NullPointerError` 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 not threads_p:
- raise NullPointerError()
-
- 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
-
- _valid = nmlib.notmuch_threads_valid
- _valid.argtypes = [NotmuchThreadsP]
- _valid.restype = bool
-
- _move_to_next = nmlib.notmuch_threads_move_to_next
- _move_to_next.argtypes = [NotmuchThreadsP]
- _move_to_next.restype = None
-
- def __next__(self):
- if not self._threads:
- raise NotInitializedError()
-
- if not self._valid(self._threads):
- self._threads = None
- raise StopIteration
-
- thread = Thread(Threads._get(self._threads), self)
- self._move_to_next(self._threads)
- return thread
- next = __next__ # python2.x iterator protocol compatibility
-
- 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 :exc:`NotInitializedError`!!!
- for thread in threads: print thread
- """
- if not self._threads:
- raise NotInitializedError()
-
- i = 0
- # returns 'bool'. On out-of-memory it returns None
- while self._valid(self._threads):
- self._move_to_next(self._threads)
- i += 1
- # reset self._threads to mark as "exhausted"
- self._threads = None
- return i
-
- def __nonzero__(self):
- """Check if :class:`Threads` contains at least one more valid thread
-
- The existence of this function makes 'if Threads: foo' work, as
- that will implicitely call len() exhausting the iterator if
- __nonzero__ does not exist. This function makes `bool(Threads())`
- work repeatedly.
-
- :return: True if there is at least one more thread in the
- Iterator, False if not. None on a "Out-of-memory" error.
- """
- return self._threads is not None and \
- self._valid(self._threads) > 0
-
- _destroy = nmlib.notmuch_threads_destroy
- _destroy.argtypes = [NotmuchThreadsP]
- _destroy.argtypes = None
-
- def __del__(self):
- """Close and free the notmuch Threads"""
- if self._threads is not None:
- self._destroy(self._threads)
-
-
projects / notmuch / blobdiff