Merge pull request #279 from deltachat/attr

introduce attr / refine GC handling

python/setup.py

@@ -11,7 +11,7 @@ def main():
         long_description = long_description,
         author='Delta Chat contributors',
         setup_requires=['cffi>=1.0.0'],
-        install_requires=['cffi>=1.0.0', 'requests'],
+        install_requires=['cffi>=1.0.0', 'requests', 'attr'],
         packages=setuptools.find_packages('src'),
         package_dir={'': 'src'},
         cffi_modules=['src/deltachat/_build.py:ffibuilder'],

python/src/deltachat/__init__.py

@@ -13,7 +13,13 @@ def py_dc_callback(ctx, evt, data1, data2):
     CFFI only allows us to set one global event handler, so this one
     looks up the correct event handler for the given context.
     """
-    callback = _DC_CALLBACK_MAP.get(ctx, lambda *a: 0)
+    try:
+        callback = _DC_CALLBACK_MAP.get(ctx, lambda *a: 0)
+    except AttributeError:
+        # we are in a deep in GC-free/interpreter shutdown land
+        # nothing much better to do here than:
+        return 0
+
     # the following code relates to the deltachat/_build.py's helper
     # function which provides us signature info of an event call
     evt_name = get_dc_event_name(evt)

python/src/deltachat/account.py

@@ -7,14 +7,17 @@ try:
 except ImportError:
     from Queue import Queue
 
+import deltachat
 from . import capi
 from .capi import ffi
-import deltachat
+from .types import cached_property
+import attr
+from attr import validators as v
 
 
-class EventHandler:
-    def __init__(self, dc_context):
-        self.dc_context = dc_context
+@attr.s
+class EventHandler(object):
+    dc_context = attr.ib(validator=v.instance_of(ffi.CData))
 
     def read_url(self, url):
         try:
@@ -75,14 +78,17 @@ class EventLogger:
                  tname, self.logid, evt_name, data1, data2))
 
 
-class Contact:
-    def __init__(self, dc_context, contact_id):
-        self.dc_context = dc_context
-        self.id = contact_id
-        self.dc_contact_t = capi.lib.dc_get_contact(self.dc_context, contact_id)
+@attr.s
+class Contact(object):
+    dc_context = attr.ib(validator=v.instance_of(ffi.CData))
+    id = attr.ib(validator=v.instance_of(int))
 
-    def __del__(self):
-        capi.lib.free(self.dc_contact_t)
+    @cached_property  # only get it once because we only free it once
+    def dc_contact_t(self):
+        return capi.lib.dc_get_contact(self.dc_context, self.id)
+
+    def __del__(self, dc_contact_unref=capi.lib.dc_contact_unref):
+        dc_contact_unref(self.dc_contact_t)
 
     @property
     def addr(self):
@@ -101,45 +107,49 @@ class Contact:
         return capi.lib.dc_contact_is_verified(self.dc_contact_t)
 
 
-class Chat:
-    def __init__(self, dc_context, chat_id):
-        self.dc_context = dc_context
-        self.id = chat_id
+@attr.s
+class Chat(object):
+    dc_context = attr.ib(validator=v.instance_of(ffi.CData))
+    id = attr.ib(validator=v.instance_of(int))
 
-    def __eq__(self, other_chat):
-        return (
-            self.dc_context == getattr(other_chat, "dc_context", None) and
-            self.id == getattr(other_chat, "id", None)
-        )
+    @cached_property
+    def dc_chat_t(self):
+        return capi.lib.dc_get_chat(self.dc_context, self.id)
 
-    def __ne__(self, other_chat):
-        return not self == other_chat
+    def __del__(self):
+        capi.lib.dc_chat_unref(self.dc_chat_t)
 
     def send_text_message(self, msg):
-        """ return ID of the message in this chat.
-        'msg' should be unicode"""
+        """ send a text message and return Message instance. """
         msg = convert_to_bytes_utf8(msg)
         print ("chat id", self.id)
-        return capi.lib.dc_send_text_msg(self.dc_context, self.id, msg)
+        msg_id = capi.lib.dc_send_text_msg(self.dc_context, self.id, msg)
+        return Message(self.dc_context, msg_id)
 
 
-class Message:
-    def __init__(self, dc_context, msg_id):
-        self.dc_context = dc_context
-        self.id = msg_id
-        self.dc_msg = capi.lib.dc_get_msg(self.dc_context, msg_id)
+@attr.s
+class Message(object):
+    dc_context = attr.ib(validator=v.instance_of(ffi.CData))
+    id = attr.ib(validator=v.instance_of(int))
+
+    @cached_property
+    def dc_msg_t(self):
+        return capi.lib.dc_get_msg(self.dc_context, self.id)
+
+    def __del__(self, dc_msg_unref=capi.lib.dc_msg_unref):
+        dc_msg_unref(self.dc_msg_t)
 
     @property
     def text(self):
-        return ffi_unicode(capi.lib.dc_msg_get_text(self.dc_msg))
+        return ffi_unicode(capi.lib.dc_msg_get_text(self.dc_msg_t))
 
     @property
     def chat(self):
-        chat_id = capi.lib.dc_msg_get_chat_id(self.dc_msg)
+        chat_id = capi.lib.dc_msg_get_chat_id(self.dc_msg_t)
         return Chat(self.dc_context, chat_id)
 
 
-class Account:
+class Account(object):
     def __init__(self, db_path, logid=None):
         self.dc_context = ctx = capi.lib.dc_context_new(
                                   capi.lib.py_dc_callback,
@@ -151,6 +161,9 @@ class Account:
         self._evlogger = EventLogger(self.dc_context, logid)
         self._threads = IOThreads(self.dc_context)
 
+    def __del__(self, dc_context_unref=capi.lib.dc_context_unref):
+        dc_context_unref(self.dc_context)
+
     def set_config(self, **kwargs):
         for name, value in kwargs.items():
             name = name.encode("utf8")
@@ -184,7 +197,7 @@ class Account:
                         self.dc_context, contact_id)
         return Chat(self.dc_context, chat_id)
 
-    def get_message(self, msg_id):
+    def get_message_by_id(self, msg_id):
         return Message(self.dc_context, msg_id)
 
     def start(self):
@@ -194,13 +207,7 @@ class Account:
 
     def shutdown(self):
         deltachat.clear_context_callback(self.dc_context)
-        self._threads.stop(wait=False)
-        # XXX actually we'd like to wait but the smtp/imap
-        # interrupt idle calls do not seem to release the
-        # blocking call to smtp|imap idle. This means we
-        # also can't now close the database because the
-        # threads might still need it.
-        # capi.lib.dc_close(self.dc_context)
+        self._threads.stop(wait=True)
 
     def _process_event(self, ctx, evt_name, data1, data2):
         assert ctx == self.dc_context
@@ -231,8 +238,6 @@ class IOThreads:
 
     def stop(self, wait=False):
         self._thread_quitflag = True
-        # XXX interrupting does not quite work yet, the threads keep idling
-        print("interrupting smtp and idle")
         capi.lib.dc_interrupt_imap_idle(self.dc_context)
         capi.lib.dc_interrupt_smtp_idle(self.dc_context)
         if wait:

python/src/deltachat/types.py

@@ -0,0 +1,20 @@
+# copied over unmodified from
+# https://github.com/devpi/devpi/blob/master/common/devpi_common/types.py
+
+
+def cached_property(f):
+    """returns a cached property that is calculated by function f"""
+    def get(self):
+        try:
+            return self._property_cache[f]
+        except AttributeError:
+            self._property_cache = {}
+        except KeyError:
+            pass
+        x = self._property_cache[f] = f(self)
+        return x
+
+    def set(self, val):
+        propcache = self.__dict__.setdefault("_property_cache", {})
+        propcache[f] = val
+    return property(get, set)

python/tests/test_account.py

@@ -28,6 +28,14 @@ class TestOfflineAccount:
         assert chat2.id == chat.id
         assert chat == chat2
         assert not (chat != chat2)
+        assert chat.dc_chat_t
+
+    def test_message(self, acfactory):
+        ac1 = acfactory.get_offline_account()
+        contact1 = ac1.create_contact("some1@hello.com", name="some1")
+        chat = ac1.create_chat_by_contact(contact1)
+        msg = chat.send_text_message("msg1")
+        assert msg
 
 
 class TestOnlineAccount:
@@ -74,14 +82,14 @@ class TestOnlineAccount:
         self.wait_successful_IMAP_SMTP_connection(ac2)
         self.wait_configuration_progress(ac1, 1000)
         self.wait_configuration_progress(ac2, 1000)
-        msg_id = chat.send_text_message("msg1")
+        msg = chat.send_text_message("msg1")
         ev = ac1._evlogger.get_matching("DC_EVENT_MSG_DELIVERED")
         evt_name, data1, data2 = ev
         assert data1 == chat.id
-        assert data2 == msg_id
+        assert data2 == msg.id
         ev = ac2._evlogger.get_matching("DC_EVENT_MSGS_CHANGED")
-        assert ev[2] == msg_id
-        msg = ac2.get_message(msg_id)
+        assert ev[2] == msg.id
+        msg = ac2.get_message_by_id(msg.id)
         assert msg.text == "msg1"
         # note that ev[1] aka data1 contains a bogus channel id
         # probably should just not get passed from the core

python/tox.ini

@@ -12,6 +12,7 @@ commands = pytest {posargs:tests}
 usedevelop = True
 deps = 
     pytest
+    pytest-faulthandler
     pdbpp
 
 [testenv:lint]