Any messages retrieved from a query - either directly via
search_messages() or indirectly via thread objects - are owned by that
query. Retrieving the same message (i.e. corresponding to the same
message ID / database object) several times will always yield the same
C object.
The caller is allowed to destroy message objects owned by a query before
the query itself - which can save memory for long-lived queries.
However, that message must then never be retrieved again from that
query.
The python-notmuch2 bindings will currently destroy every message object
in Message._destroy(), which will lead to an invalid free if the same
message is then retrieved again. E.g. the following python program leads
to libtalloc abort()ing:
import notmuch2
db = notmuch2.Database(mode = notmuch2.Database.MODE.READ_ONLY)
t = next(db.threads('*'))
msgs = list(zip(t.toplevel(), t.toplevel()))
msgs = list(zip(t.toplevel(), t.toplevel()))
Fix this issue by creating a subclass of Message, which is used for
"standalone" message which have to be freed by the caller. Message class
is then used only for messages descended from a query, which do not need
to be freed by the caller.
capi.lib.NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID]
if ret not in ok:
raise errors.NotmuchError(ret)
capi.lib.NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID]
if ret not in ok:
raise errors.NotmuchError(ret)
- msg = message.Message(self, msg_pp[0], db=self)
+ msg = message.StandaloneMessage(self, msg_pp[0], db=self)
if sync_flags:
msg.tags.from_maildir_flags()
return self.AddedMessage(
if sync_flags:
msg.tags.from_maildir_flags()
return self.AddedMessage(
msg_p = msg_pp[0]
if msg_p == capi.ffi.NULL:
raise LookupError
msg_p = msg_pp[0]
if msg_p == capi.ffi.NULL:
raise LookupError
- msg = message.Message(self, msg_p, db=self)
+ msg = message.StandaloneMessage(self, msg_p, db=self)
return msg
def get(self, filename):
return msg
def get(self, filename):
msg_p = msg_pp[0]
if msg_p == capi.ffi.NULL:
raise LookupError
msg_p = msg_pp[0]
if msg_p == capi.ffi.NULL:
raise LookupError
- msg = message.Message(self, msg_p, db=self)
+ msg = message.StandaloneMessage(self, msg_p, db=self)
class Message(base.NotmuchObject):
class Message(base.NotmuchObject):
- """An email message stored in the notmuch database.
+ """An email message stored in the notmuch database retrieved via a query.
This should not be directly created, instead it will be returned
by calling methods on :class:`Database`. A message keeps a
This should not be directly created, instead it will be returned
by calling methods on :class:`Database`. A message keeps a
@property
def alive(self):
@property
def alive(self):
- if not self._parent.alive:
- return False
- try:
- self._msg_p
- except errors.ObjectDestroyedError:
- return False
- else:
- return True
-
- def __del__(self):
- self._destroy()
+ return self._parent.alive
- if self.alive:
- capi.lib.notmuch_message_destroy(self._msg_p)
- self._msg_p = None
@property
def messageid(self):
@property
def messageid(self):
if isinstance(other, self.__class__):
return self.messageid == other.messageid
if isinstance(other, self.__class__):
return self.messageid == other.messageid
+class StandaloneMessage(Message):
+ """An email message stored in the notmuch database.
+
+ This subclass of Message is used for messages that are retrieved from the
+ database directly and are not owned by a query.
+ """
+ @property
+ def alive(self):
+ if not self._parent.alive:
+ return False
+ try:
+ self._msg_p
+ except errors.ObjectDestroyedError:
+ return False
+ else:
+ return True
+
+ def __del__(self):
+ self._destroy()
+
+ def _destroy(self):
+ if self.alive:
+ capi.lib.notmuch_message_destroy(self._msg_p)
+ self._msg_p = None
class FilenamesIter(base.NotmuchIter):
"""Iterator for binary filenames objects."""
class FilenamesIter(base.NotmuchIter):
"""Iterator for binary filenames objects."""