Replace _event_dict_property with DictProperty

this amounts to the same thing, but replaces `_event_dict` with `_dict`, and
removes some of the function layers generated by `property`.
This commit is contained in:
Richard van der Hoff 2020-02-07 13:08:34 +00:00
parent 49f877d32e
commit 43b2be9764
2 changed files with 80 additions and 66 deletions

View file

@ -37,6 +37,65 @@ from synapse.util.frozenutils import freeze
USE_FROZEN_DICTS = strtobool(os.environ.get("SYNAPSE_USE_FROZEN_DICTS", "0"))
class DictProperty:
"""An object property which delegates to the `_dict` within its parent object."""
__slots__ = ["key"]
def __init__(self, key: str):
self.key = key
def __get__(self, instance, owner=None):
# if the property is accessed as a class property rather than an instance
# property, return the property itself rather than the value
if instance is None:
return self
try:
return instance._dict[self.key]
except KeyError as e1:
# We want this to look like a regular attribute error (mostly so that
# hasattr() works correctly), so we convert the KeyError into an
# AttributeError.
#
# To exclude the KeyError from the traceback, we explicitly
# 'raise from e1.__context__' (which is better than 'raise from None',
# becuase that would omit any *earlier* exceptions).
#
raise AttributeError(
"'%s' has no '%s' property" % (type(instance), self.key)
) from e1.__context__
def __set__(self, instance, v):
instance._dict[self.key] = v
def __delete__(self, instance):
try:
del instance._dict[self.key]
except KeyError as e1:
raise AttributeError(
"'%s' has no '%s' property" % (type(instance), self.key)
) from e1.__context__
class DefaultDictProperty(DictProperty):
"""An extension of DictProperty which provides a default if the property is
not present in the parent's _dict.
Note that this means that hasattr() on the property always returns True.
"""
__slots__ = ["default"]
def __init__(self, key, default):
super().__init__(key)
self.default = default
def __get__(self, instance, owner=None):
if instance is None:
return self
return instance._dict.get(self.key, self.default)
class _EventInternalMetadata(object):
def __init__(self, internal_metadata_dict):
self.__dict__ = dict(internal_metadata_dict)
@ -117,51 +176,6 @@ class _EventInternalMetadata(object):
return getattr(self, "redacted", False)
_SENTINEL = object()
def _event_dict_property(key, default=_SENTINEL):
"""Creates a new property for the given key that delegates access to
`self._event_dict`.
The default is used if the key is missing from the `_event_dict`, if given,
otherwise an AttributeError will be raised.
Note: If a default is given then `hasattr` will always return true.
"""
# We want to be able to use hasattr with the event dict properties.
# However, (on python3) hasattr expects AttributeError to be raised. Hence,
# we need to transform the KeyError into an AttributeError
def getter_raises(self):
try:
return self._event_dict[key]
except KeyError:
raise AttributeError(key)
def getter_default(self):
return self._event_dict.get(key, default)
def setter(self, v):
try:
self._event_dict[key] = v
except KeyError:
raise AttributeError(key)
def delete(self):
try:
del self._event_dict[key]
except KeyError:
raise AttributeError(key)
if default is _SENTINEL:
# No default given, so use the getter that raises
return property(getter_raises, setter, delete)
else:
return property(getter_default, setter, delete)
class EventBase(object):
def __init__(
self,
@ -175,23 +189,23 @@ class EventBase(object):
self.unsigned = unsigned
self.rejected_reason = rejected_reason
self._event_dict = event_dict
self._dict = event_dict
self.internal_metadata = _EventInternalMetadata(internal_metadata_dict)
auth_events = _event_dict_property("auth_events")
depth = _event_dict_property("depth")
content = _event_dict_property("content")
hashes = _event_dict_property("hashes")
origin = _event_dict_property("origin")
origin_server_ts = _event_dict_property("origin_server_ts")
prev_events = _event_dict_property("prev_events")
redacts = _event_dict_property("redacts", None)
room_id = _event_dict_property("room_id")
sender = _event_dict_property("sender")
state_key = _event_dict_property("state_key")
type = _event_dict_property("type")
user_id = _event_dict_property("sender")
auth_events = DictProperty("auth_events")
depth = DictProperty("depth")
content = DictProperty("content")
hashes = DictProperty("hashes")
origin = DictProperty("origin")
origin_server_ts = DictProperty("origin_server_ts")
prev_events = DictProperty("prev_events")
redacts = DefaultDictProperty("redacts", None)
room_id = DictProperty("room_id")
sender = DictProperty("sender")
state_key = DictProperty("state_key")
type = DictProperty("type")
user_id = DictProperty("sender")
@property
def event_id(self) -> str:
@ -205,13 +219,13 @@ class EventBase(object):
return hasattr(self, "state_key") and self.state_key is not None
def get_dict(self) -> JsonDict:
d = dict(self._event_dict)
d = dict(self._dict)
d.update({"signatures": self.signatures, "unsigned": dict(self.unsigned)})
return d
def get(self, key, default=None):
return self._event_dict.get(key, default)
return self._dict.get(key, default)
def get_internal_metadata_dict(self):
return self.internal_metadata.get_dict()
@ -233,16 +247,16 @@ class EventBase(object):
raise AttributeError("Unrecognized attribute %s" % (instance,))
def __getitem__(self, field):
return self._event_dict[field]
return self._dict[field]
def __contains__(self, field):
return field in self._event_dict
return field in self._dict
def items(self):
return list(self._event_dict.items())
return list(self._dict.items())
def keys(self):
return six.iterkeys(self._event_dict)
return six.iterkeys(self._dict)
def prev_event_ids(self):
"""Returns the list of prev event IDs. The order matches the order

View file

@ -240,7 +240,7 @@ class RedactionTestCase(unittest.HomeserverTestCase):
built_event = yield self._base_builder.build(prev_event_ids)
built_event._event_id = self._event_id
built_event._event_dict["event_id"] = self._event_id
built_event._dict["event_id"] = self._event_id
assert built_event.event_id == self._event_id
return built_event