-class Query(object):
- """Represents a search query on an opened :class:`Database`.
-
- A query selects and filters a subset of messages from the notmuch
- database we derive from.
-
- :class:`Query` provides an instance attribute :attr:`sort`, which
- contains the sort order (if specified via :meth:`set_sort`) or
- `None`.
-
- Any function in this class may throw an :exc:`NotInitializedError`
- in case the underlying query object was not set up correctly.
-
- .. note:: Do remember that as soon as we tear down this object,
- all underlying derived objects such as threads,
- messages, tags etc will be freed by the underlying library
- as well. Accessing these objects will lead to segfaults and
- other unexpected behavior. See above for more details.
- """
- # constants
- SORT = Enum(['OLDEST_FIRST', 'NEWEST_FIRST', 'MESSAGE_ID', 'UNSORTED'])
- """Constants: Sort order in which to return results"""
-
- """notmuch_query_create"""
- _create = nmlib.notmuch_query_create
- _create.argtypes = [NotmuchDatabaseP, c_char_p]
- _create.restype = NotmuchQueryP
-
- """notmuch_query_search_threads"""
- _search_threads = nmlib.notmuch_query_search_threads
- _search_threads.argtypes = [NotmuchQueryP]
- _search_threads.restype = NotmuchThreadsP
-
- """notmuch_query_search_messages"""
- _search_messages = nmlib.notmuch_query_search_messages
- _search_messages.argtypes = [NotmuchQueryP]
- _search_messages.restype = NotmuchMessagesP
-
- """notmuch_query_count_messages"""
- _count_messages = nmlib.notmuch_query_count_messages
- _count_messages.argtypes = [NotmuchQueryP]
- _count_messages.restype = c_uint
-
- def __init__(self, db, querystr):
- """
- :param db: An open database which we derive the Query from.
- :type db: :class:`Database`
- :param querystr: The query string for the message.
- :type querystr: utf-8 encoded str or unicode
- """
- self._db = None
- self._query = None
- self.sort = None
- self.create(db, querystr)
-
- def _assert_query_is_initialized(self):
- """Raises :exc:`NotInitializedError` if self._query is `None`"""
- if self._query is None:
- raise NotInitializedError()
-
- def create(self, db, querystr):
- """Creates a new query derived from a Database
-
- This function is utilized by __init__() and usually does not need to
- be called directly.
-
- :param db: Database to create the query from.
- :type db: :class:`Database`
- :param querystr: The query string
- :type querystr: utf-8 encoded str or unicode
- :returns: Nothing
- :exception:
- :exc:`NullPointerError` if the query creation failed
- (e.g. too little memory).
- :exc:`NotInitializedError` if the underlying db was not
- intitialized.
- """
- db._assert_db_is_initialized()
- # create reference to parent db to keep it alive
- self._db = db
- # create query, return None if too little mem available
- query_p = Query._create(db.db_p, _str(querystr))
- if query_p is None:
- raise NullPointerError
- self._query = query_p
-
- _set_sort = nmlib.notmuch_query_set_sort
- _set_sort.argtypes = [NotmuchQueryP, c_uint]
- _set_sort.argtypes = None
-
- def set_sort(self, sort):
- """Set the sort order future results will be delivered in
-
- :param sort: Sort order (see :attr:`Query.SORT`)
- """
- self._assert_query_is_initialized()
- self.sort = sort
- self._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.
-
- The method sets :attr:`Message.FLAG`\.MATCH for those messages that
- match the query. The method :meth:`Message.get_flag` allows us
- to get the value of this flag.
-
- :returns: :class:`Threads`
- :exception: :exc:`NullPointerError` if search_threads failed
- """
- self._assert_query_is_initialized()
- threads_p = Query._search_threads(self._query)
-
- if threads_p is None:
- raise NullPointerError
- return Threads(threads_p, self)
-
- def search_messages(self):
- """Filter messages according to the query and return
- :class:`Messages` in the defined sort order
-
- :returns: :class:`Messages`
- :exception: :exc:`NullPointerError` if search_messages failed
- """
- self._assert_query_is_initialized()
- msgs_p = Query._search_messages(self._query)
-
- if msgs_p is None:
- raise NullPointerError
- return Messages(msgs_p, self)
-
- def count_messages(self):
- """Estimate the number of messages matching the query
-
- This function performs a search and returns Xapian's best
- guess as to the number of matching messages. It is much faster
- than performing :meth:`search_messages` and counting the
- result with `len()` (although it always returned the same
- result in my tests). Technically, it wraps the underlying
- *notmuch_query_count_messages* function.
-
- :returns: :class:`Messages`
- """
- self._assert_query_is_initialized()
- return Query._count_messages(self._query)
-
- _destroy = nmlib.notmuch_query_destroy
- _destroy.argtypes = [NotmuchQueryP]
- _destroy.restype = None
-
- def __del__(self):
- """Close and free the Query"""
- if self._query is not None:
- self._destroy(self._query)
-
-
projects / notmuch / blobdiff