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- # Copyright 2014-2016 OpenMarket Ltd
- # Copyright 2019 New Vector Ltd
- # Copyright 2020 The Matrix.org Foundation C.I.C.
- #
- # Licensed under the Apache License, Version 2.0 (the "License");
- # you may not use this file except in compliance with the License.
- # You may obtain a copy of the License at
- #
- # http://www.apache.org/licenses/LICENSE-2.0
- #
- # Unless required by applicable law or agreed to in writing, software
- # distributed under the License is distributed on an "AS IS" BASIS,
- # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- # See the License for the specific language governing permissions and
- # limitations under the License.
-
- import abc
- import os
- from typing import Dict, Optional, Tuple, Type
-
- from unpaddedbase64 import encode_base64
-
- from synapse.api.room_versions import EventFormatVersions, RoomVersion, RoomVersions
- from synapse.types import JsonDict, RoomStreamToken
- from synapse.util.caches import intern_dict
- from synapse.util.frozenutils import freeze
- from synapse.util.stringutils import strtobool
-
- # Whether we should use frozen_dict in FrozenEvent. Using frozen_dicts prevents
- # bugs where we accidentally share e.g. signature dicts. However, converting a
- # dict to frozen_dicts is expensive.
- #
- # NOTE: This is overridden by the configuration by the Synapse worker apps, but
- # for the sake of tests, it is set here while it cannot be configured on the
- # homeserver object itself.
-
- 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',
- # because 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:
- __slots__ = ["_dict", "stream_ordering", "outlier"]
-
- def __init__(self, internal_metadata_dict: JsonDict):
- # we have to copy the dict, because it turns out that the same dict is
- # reused. TODO: fix that
- self._dict = dict(internal_metadata_dict)
-
- # the stream ordering of this event. None, until it has been persisted.
- self.stream_ordering = None # type: Optional[int]
-
- # whether this event is an outlier (ie, whether we have the state at that point
- # in the DAG)
- self.outlier = False
-
- out_of_band_membership = DictProperty("out_of_band_membership") # type: bool
- send_on_behalf_of = DictProperty("send_on_behalf_of") # type: str
- recheck_redaction = DictProperty("recheck_redaction") # type: bool
- soft_failed = DictProperty("soft_failed") # type: bool
- proactively_send = DictProperty("proactively_send") # type: bool
- redacted = DictProperty("redacted") # type: bool
- txn_id = DictProperty("txn_id") # type: str
- token_id = DictProperty("token_id") # type: str
-
- # XXX: These are set by StreamWorkerStore._set_before_and_after.
- # I'm pretty sure that these are never persisted to the database, so shouldn't
- # be here
- before = DictProperty("before") # type: RoomStreamToken
- after = DictProperty("after") # type: RoomStreamToken
- order = DictProperty("order") # type: Tuple[int, int]
-
- def get_dict(self) -> JsonDict:
- return dict(self._dict)
-
- def is_outlier(self) -> bool:
- return self.outlier
-
- def is_out_of_band_membership(self) -> bool:
- """Whether this is an out of band membership, like an invite or an invite
- rejection. This is needed as those events are marked as outliers, but
- they still need to be processed as if they're new events (e.g. updating
- invite state in the database, relaying to clients, etc).
-
- (Added in synapse 0.99.0, so may be unreliable for events received before that)
- """
- return self._dict.get("out_of_band_membership", False)
-
- def get_send_on_behalf_of(self) -> Optional[str]:
- """Whether this server should send the event on behalf of another server.
- This is used by the federation "send_join" API to forward the initial join
- event for a server in the room.
-
- returns a str with the name of the server this event is sent on behalf of.
- """
- return self._dict.get("send_on_behalf_of")
-
- def need_to_check_redaction(self) -> bool:
- """Whether the redaction event needs to be rechecked when fetching
- from the database.
-
- Starting in room v3 redaction events are accepted up front, and later
- checked to see if the redacter and redactee's domains match.
-
- If the sender of the redaction event is allowed to redact any event
- due to auth rules, then this will always return false.
-
- Returns:
- bool
- """
- return self._dict.get("recheck_redaction", False)
-
- def is_soft_failed(self) -> bool:
- """Whether the event has been soft failed.
-
- Soft failed events should be handled as usual, except:
- 1. They should not go down sync or event streams, or generally
- sent to clients.
- 2. They should not be added to the forward extremities (and
- therefore not to current state).
-
- Returns:
- bool
- """
- return self._dict.get("soft_failed", False)
-
- def should_proactively_send(self):
- """Whether the event, if ours, should be sent to other clients and
- servers.
-
- This is used for sending dummy events internally. Servers and clients
- can still explicitly fetch the event.
-
- Returns:
- bool
- """
- return self._dict.get("proactively_send", True)
-
- def is_redacted(self):
- """Whether the event has been redacted.
-
- This is used for efficiently checking whether an event has been
- marked as redacted without needing to make another database call.
-
- Returns:
- bool
- """
- return self._dict.get("redacted", False)
-
-
- class EventBase(metaclass=abc.ABCMeta):
- @property
- @abc.abstractmethod
- def format_version(self) -> int:
- """The EventFormatVersion implemented by this event"""
- ...
-
- def __init__(
- self,
- event_dict: JsonDict,
- room_version: RoomVersion,
- signatures: Dict[str, Dict[str, str]],
- unsigned: JsonDict,
- internal_metadata_dict: JsonDict,
- rejected_reason: Optional[str],
- ):
- assert room_version.event_format == self.format_version
-
- self.room_version = room_version
- self.signatures = signatures
- self.unsigned = unsigned
- self.rejected_reason = rejected_reason
-
- self._dict = event_dict
-
- self.internal_metadata = _EventInternalMetadata(internal_metadata_dict)
-
- 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:
- raise NotImplementedError()
-
- @property
- def membership(self):
- return self.content["membership"]
-
- def is_state(self):
- return hasattr(self, "state_key") and self.state_key is not None
-
- def get_dict(self) -> JsonDict:
- d = dict(self._dict)
- d.update({"signatures": self.signatures, "unsigned": dict(self.unsigned)})
-
- return d
-
- def get(self, key, default=None):
- return self._dict.get(key, default)
-
- def get_internal_metadata_dict(self):
- return self.internal_metadata.get_dict()
-
- def get_pdu_json(self, time_now=None) -> JsonDict:
- pdu_json = self.get_dict()
-
- if time_now is not None and "age_ts" in pdu_json["unsigned"]:
- age = time_now - pdu_json["unsigned"]["age_ts"]
- pdu_json.setdefault("unsigned", {})["age"] = int(age)
- del pdu_json["unsigned"]["age_ts"]
-
- # This may be a frozen event
- pdu_json["unsigned"].pop("redacted_because", None)
-
- return pdu_json
-
- def __set__(self, instance, value):
- raise AttributeError("Unrecognized attribute %s" % (instance,))
-
- def __getitem__(self, field):
- return self._dict[field]
-
- def __contains__(self, field):
- return field in self._dict
-
- def items(self):
- return list(self._dict.items())
-
- def keys(self):
- return self._dict.keys()
-
- def prev_event_ids(self):
- """Returns the list of prev event IDs. The order matches the order
- specified in the event, though there is no meaning to it.
-
- Returns:
- list[str]: The list of event IDs of this event's prev_events
- """
- return [e for e, _ in self.prev_events]
-
- def auth_event_ids(self):
- """Returns the list of auth event IDs. The order matches the order
- specified in the event, though there is no meaning to it.
-
- Returns:
- list[str]: The list of event IDs of this event's auth_events
- """
- return [e for e, _ in self.auth_events]
-
- def freeze(self):
- """'Freeze' the event dict, so it cannot be modified by accident"""
-
- # this will be a no-op if the event dict is already frozen.
- self._dict = freeze(self._dict)
-
-
- class FrozenEvent(EventBase):
- format_version = EventFormatVersions.V1 # All events of this type are V1
-
- def __init__(
- self,
- event_dict: JsonDict,
- room_version: RoomVersion,
- internal_metadata_dict: Optional[JsonDict] = None,
- rejected_reason: Optional[str] = None,
- ):
- internal_metadata_dict = internal_metadata_dict or {}
-
- event_dict = dict(event_dict)
-
- # Signatures is a dict of dicts, and this is faster than doing a
- # copy.deepcopy
- signatures = {
- name: {sig_id: sig for sig_id, sig in sigs.items()}
- for name, sigs in event_dict.pop("signatures", {}).items()
- }
-
- unsigned = dict(event_dict.pop("unsigned", {}))
-
- # We intern these strings because they turn up a lot (especially when
- # caching).
- event_dict = intern_dict(event_dict)
-
- if USE_FROZEN_DICTS:
- frozen_dict = freeze(event_dict)
- else:
- frozen_dict = event_dict
-
- self._event_id = event_dict["event_id"]
-
- super().__init__(
- frozen_dict,
- room_version=room_version,
- signatures=signatures,
- unsigned=unsigned,
- internal_metadata_dict=internal_metadata_dict,
- rejected_reason=rejected_reason,
- )
-
- @property
- def event_id(self) -> str:
- return self._event_id
-
- def __str__(self):
- return self.__repr__()
-
- def __repr__(self):
- return "<FrozenEvent event_id=%r, type=%r, state_key=%r>" % (
- self.get("event_id", None),
- self.get("type", None),
- self.get("state_key", None),
- )
-
-
- class FrozenEventV2(EventBase):
- format_version = EventFormatVersions.V2 # All events of this type are V2
-
- def __init__(
- self,
- event_dict: JsonDict,
- room_version: RoomVersion,
- internal_metadata_dict: Optional[JsonDict] = None,
- rejected_reason: Optional[str] = None,
- ):
- internal_metadata_dict = internal_metadata_dict or {}
-
- event_dict = dict(event_dict)
-
- # Signatures is a dict of dicts, and this is faster than doing a
- # copy.deepcopy
- signatures = {
- name: {sig_id: sig for sig_id, sig in sigs.items()}
- for name, sigs in event_dict.pop("signatures", {}).items()
- }
-
- assert "event_id" not in event_dict
-
- unsigned = dict(event_dict.pop("unsigned", {}))
-
- # We intern these strings because they turn up a lot (especially when
- # caching).
- event_dict = intern_dict(event_dict)
-
- if USE_FROZEN_DICTS:
- frozen_dict = freeze(event_dict)
- else:
- frozen_dict = event_dict
-
- self._event_id = None
-
- super().__init__(
- frozen_dict,
- room_version=room_version,
- signatures=signatures,
- unsigned=unsigned,
- internal_metadata_dict=internal_metadata_dict,
- rejected_reason=rejected_reason,
- )
-
- @property
- def event_id(self):
- # We have to import this here as otherwise we get an import loop which
- # is hard to break.
- from synapse.crypto.event_signing import compute_event_reference_hash
-
- if self._event_id:
- return self._event_id
- self._event_id = "$" + encode_base64(compute_event_reference_hash(self)[1])
- return self._event_id
-
- def prev_event_ids(self):
- """Returns the list of prev event IDs. The order matches the order
- specified in the event, though there is no meaning to it.
-
- Returns:
- list[str]: The list of event IDs of this event's prev_events
- """
- return self.prev_events
-
- def auth_event_ids(self):
- """Returns the list of auth event IDs. The order matches the order
- specified in the event, though there is no meaning to it.
-
- Returns:
- list[str]: The list of event IDs of this event's auth_events
- """
- return self.auth_events
-
- def __str__(self):
- return self.__repr__()
-
- def __repr__(self):
- return "<%s event_id=%r, type=%r, state_key=%r>" % (
- self.__class__.__name__,
- self.event_id,
- self.get("type", None),
- self.get("state_key", None),
- )
-
-
- class FrozenEventV3(FrozenEventV2):
- """FrozenEventV3, which differs from FrozenEventV2 only in the event_id format"""
-
- format_version = EventFormatVersions.V3 # All events of this type are V3
-
- @property
- def event_id(self):
- # We have to import this here as otherwise we get an import loop which
- # is hard to break.
- from synapse.crypto.event_signing import compute_event_reference_hash
-
- if self._event_id:
- return self._event_id
- self._event_id = "$" + encode_base64(
- compute_event_reference_hash(self)[1], urlsafe=True
- )
- return self._event_id
-
-
- def _event_type_from_format_version(format_version: int) -> Type[EventBase]:
- """Returns the python type to use to construct an Event object for the
- given event format version.
-
- Args:
- format_version (int): The event format version
-
- Returns:
- type: A type that can be initialized as per the initializer of
- `FrozenEvent`
- """
-
- if format_version == EventFormatVersions.V1:
- return FrozenEvent
- elif format_version == EventFormatVersions.V2:
- return FrozenEventV2
- elif format_version == EventFormatVersions.V3:
- return FrozenEventV3
- else:
- raise Exception("No event format %r" % (format_version,))
-
-
- def make_event_from_dict(
- event_dict: JsonDict,
- room_version: RoomVersion = RoomVersions.V1,
- internal_metadata_dict: Optional[JsonDict] = None,
- rejected_reason: Optional[str] = None,
- ) -> EventBase:
- """Construct an EventBase from the given event dict"""
- event_type = _event_type_from_format_version(room_version.event_format)
- return event_type(
- event_dict, room_version, internal_metadata_dict or {}, rejected_reason
- )
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