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Diffstat (limited to 'bindings/python/notmuch/query.py')
-rw-r--r-- | bindings/python/notmuch/query.py | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/bindings/python/notmuch/query.py b/bindings/python/notmuch/query.py new file mode 100644 index 0000000..4abba5b --- /dev/null +++ b/bindings/python/notmuch/query.py @@ -0,0 +1,207 @@ +""" +This file is part of notmuch. + +Notmuch is free software: you can redistribute it and/or modify it +under the terms of the GNU General Public License as published by the +Free Software Foundation, either version 3 of the License, or (at your +option) any later version. + +Notmuch is distributed in the hope that it will be useful, but WITHOUT +ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with notmuch. If not, see <http://www.gnu.org/licenses/>. + +Copyright 2010 Sebastian Spaeth <Sebastian@SSpaeth.de> +""" + +from ctypes import c_char_p, c_uint +from .globals import ( + nmlib, + Enum, + _str, + NotmuchQueryP, + NotmuchThreadsP, + NotmuchDatabaseP, + NotmuchMessagesP, +) +from .errors import ( + NullPointerError, + NotInitializedError, +) +from .threads import Threads +from .messages import Messages + + +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""" + + 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 not self._query: + raise NotInitializedError() + + """notmuch_query_create""" + _create = nmlib.notmuch_query_create + _create.argtypes = [NotmuchDatabaseP, c_char_p] + _create.restype = NotmuchQueryP + + 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 + :raises: + :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 not query_p: + 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) + + """notmuch_query_search_threads""" + _search_threads = nmlib.notmuch_query_search_threads + _search_threads.argtypes = [NotmuchQueryP] + _search_threads.restype = NotmuchThreadsP + + 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` + :raises: :exc:`NullPointerError` if search_threads failed + """ + self._assert_query_is_initialized() + threads_p = Query._search_threads(self._query) + + if not threads_p: + raise NullPointerError + return Threads(threads_p, self) + + """notmuch_query_search_messages""" + _search_messages = nmlib.notmuch_query_search_messages + _search_messages.argtypes = [NotmuchQueryP] + _search_messages.restype = NotmuchMessagesP + + def search_messages(self): + """Filter messages according to the query and return + :class:`Messages` in the defined sort order + + :returns: :class:`Messages` + :raises: :exc:`NullPointerError` if search_messages failed + """ + self._assert_query_is_initialized() + msgs_p = Query._search_messages(self._query) + + if not msgs_p: + raise NullPointerError + return Messages(msgs_p, self) + + _count_messages = nmlib.notmuch_query_count_messages + _count_messages.argtypes = [NotmuchQueryP] + _count_messages.restype = c_uint + + def count_messages(self): + ''' + This function performs a search and returns Xapian's best + guess as to the number of matching messages. + + :returns: the estimated number of messages matching this query + :rtype: int + ''' + self._assert_query_is_initialized() + return Query._count_messages(self._query) + + _count_threads = nmlib.notmuch_query_count_threads + _count_threads.argtypes = [NotmuchQueryP] + _count_threads.restype = c_uint + + def count_threads(self): + ''' + This function performs a search and returns the number of + unique thread IDs in the matching messages. This is the same + as number of threads matching a search. + + Note that this is a significantly heavier operation than + meth:`Query.count_messages`. + + :returns: the number of threads returned by this query + :rtype: int + ''' + self._assert_query_is_initialized() + return Query._count_threads(self._query) + + _destroy = nmlib.notmuch_query_destroy + _destroy.argtypes = [NotmuchQueryP] + _destroy.restype = None + + def __del__(self): + """Close and free the Query""" + if self._query: + self._destroy(self._query) |