From be47cfa9c97b4acfd884440f1953ed000225eb37 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Fri, 25 Jan 2019 17:19:31 +0000 Subject: Refactor event building into EventBuilder This is so that everything is done in one place, making it easier to change the event format based on room version --- synapse/events/builder.py | 284 ++++++++++++++++++++++++-------- synapse/federation/federation_client.py | 20 +-- synapse/handlers/message.py | 34 +--- synapse/server.py | 5 +- synapse/storage/event_federation.py | 23 +++ 5 files changed, 254 insertions(+), 112 deletions(-) diff --git a/synapse/events/builder.py b/synapse/events/builder.py index 7e63371095..225b5fd670 100644 --- a/synapse/events/builder.py +++ b/synapse/events/builder.py @@ -13,79 +13,156 @@ # See the License for the specific language governing permissions and # limitations under the License. -import copy +import attr -from synapse.api.constants import RoomVersions +from twisted.internet import defer + +from synapse.api.constants import ( + KNOWN_EVENT_FORMAT_VERSIONS, + KNOWN_ROOM_VERSIONS, + MAX_DEPTH, +) +from synapse.crypto.event_signing import add_hashes_and_signatures from synapse.types import EventID from synapse.util.stringutils import random_string -from . import EventBase, FrozenEvent, _event_dict_property +from . import ( + _EventInternalMetadata, + event_type_from_format_version, + room_version_to_event_format, +) -def get_event_builder(room_version, key_values={}, internal_metadata_dict={}): - """Generate an event builder appropriate for the given room version +@attr.s(slots=True, cmp=False, frozen=True) +class EventBuilder(object): + """A format independent event builder used to build up the event content + before signing the event. - Args: - room_version (str): Version of the room that we're creating an - event builder for - key_values (dict): Fields used as the basis of the new event - internal_metadata_dict (dict): Used to create the `_EventInternalMetadata` - object. + (Note that while objects of this class are frozen, the + content/unsigned/internal_metadata fields are still mutable) - Returns: - EventBuilder + Attributes: + format_version (int): Event format version + room_id (str) + type (str) + sender (str) + content (dict) + unsigned (dict) + internal_metadata (_EventInternalMetadata) + + _state (StateHandler) + _auth (synapse.api.Auth) + _store (DataStore) + _clock (Clock) + _hostname (str): The hostname of the server creating the event + _signing_key: The signing key to use to sign the event as the server """ - if room_version in { - RoomVersions.V1, - RoomVersions.V2, - RoomVersions.VDH_TEST, - RoomVersions.STATE_V2_TEST, - }: - return EventBuilder(key_values, internal_metadata_dict) - else: - raise Exception( - "No event format defined for version %r" % (room_version,) - ) + _state = attr.ib() + _auth = attr.ib() + _store = attr.ib() + _clock = attr.ib() + _hostname = attr.ib() + _signing_key = attr.ib() + + format_version = attr.ib() + + room_id = attr.ib() + type = attr.ib() + sender = attr.ib() + + content = attr.ib(default=attr.Factory(dict)) + unsigned = attr.ib(default=attr.Factory(dict)) + + # These only exist on a subset of events, so they raise AttributeError if + # someone tries to get them when they don't exist. + _state_key = attr.ib(default=None) + _redacts = attr.ib(default=None) + + internal_metadata = attr.ib(default=attr.Factory(lambda: _EventInternalMetadata({}))) + + @property + def state_key(self): + if self._state_key is not None: + return self._state_key + + raise AttributeError("state_key") + + def is_state(self): + return self._state_key is not None -class EventBuilder(EventBase): - def __init__(self, key_values={}, internal_metadata_dict={}): - signatures = copy.deepcopy(key_values.pop("signatures", {})) - unsigned = copy.deepcopy(key_values.pop("unsigned", {})) + @defer.inlineCallbacks + def build(self, prev_event_ids): + """Transform into a fully signed and hashed event - super(EventBuilder, self).__init__( - key_values, - signatures=signatures, - unsigned=unsigned, - internal_metadata_dict=internal_metadata_dict, + Args: + prev_event_ids (list[str]): The event IDs to use as the prev events + + Returns: + Deferred[FrozenEvent] + """ + + state_ids = yield self._state.get_current_state_ids( + self.room_id, prev_event_ids, + ) + auth_ids = yield self._auth.compute_auth_events( + self, state_ids, ) - event_id = _event_dict_property("event_id") - state_key = _event_dict_property("state_key") - type = _event_dict_property("type") + auth_events = yield self._store.add_event_hashes(auth_ids) + prev_events = yield self._store.add_event_hashes(prev_event_ids) - def build(self): - return FrozenEvent.from_event(self) + old_depth = yield self._store.get_max_depth_of( + prev_event_ids, + ) + depth = old_depth + 1 + # we cap depth of generated events, to ensure that they are not + # rejected by other servers (and so that they can be persisted in + # the db) + depth = min(depth, MAX_DEPTH) -class EventBuilderFactory(object): - def __init__(self, clock, hostname): - self.clock = clock - self.hostname = hostname + event_dict = { + "auth_events": auth_events, + "prev_events": prev_events, + "type": self.type, + "room_id": self.room_id, + "sender": self.sender, + "content": self.content, + "unsigned": self.unsigned, + "depth": depth, + "prev_state": [], + } + + if self.is_state(): + event_dict["state_key"] = self._state_key - self.event_id_count = 0 + if self._redacts is not None: + event_dict["redacts"] = self._redacts - def create_event_id(self): - i = str(self.event_id_count) - self.event_id_count += 1 + defer.returnValue( + create_local_event_from_event_dict( + clock=self._clock, + hostname=self._hostname, + signing_key=self._signing_key, + format_version=self.format_version, + event_dict=event_dict, + internal_metadata_dict=self.internal_metadata.get_dict(), + ) + ) - local_part = str(int(self.clock.time())) + i + random_string(5) - e_id = EventID(local_part, self.hostname) +class EventBuilderFactory(object): + def __init__(self, hs): + self.clock = hs.get_clock() + self.hostname = hs.hostname + self.signing_key = hs.config.signing_key[0] - return e_id.to_string() + self.store = hs.get_datastore() + self.state = hs.get_state_handler() + self.auth = hs.get_auth() - def new(self, room_version, key_values={}): + def new(self, room_version, key_values): """Generate an event builder appropriate for the given room version Args: @@ -98,27 +175,104 @@ class EventBuilderFactory(object): """ # There's currently only the one event version defined - if room_version not in { - RoomVersions.V1, - RoomVersions.V2, - RoomVersions.VDH_TEST, - RoomVersions.STATE_V2_TEST, - }: + if room_version not in KNOWN_ROOM_VERSIONS: raise Exception( "No event format defined for version %r" % (room_version,) ) - key_values["event_id"] = self.create_event_id() + key_values["event_id"] = _create_event_id(self.clock, self.hostname) + + return EventBuilder( + store=self.store, + state=self.state, + auth=self.auth, + clock=self.clock, + hostname=self.hostname, + signing_key=self.signing_key, + format_version=room_version_to_event_format(room_version), + type=key_values["type"], + state_key=key_values.get("state_key"), + room_id=key_values["room_id"], + sender=key_values["sender"], + content=key_values.get("content", {}), + unsigned=key_values.get("unsigned", {}), + redacts=key_values.get("redacts", None), + ) + + +def create_local_event_from_event_dict(clock, hostname, signing_key, + format_version, event_dict, + internal_metadata_dict=None): + """Takes a fully formed event dict, ensuring that fields like `origin` + and `origin_server_ts` have correct values for a locally produced event, + then signs and hashes it. + + Args: + clock (Clock) + hostname (str) + signing_key + format_version (int) + event_dict (dict) + internal_metadata_dict (dict|None) + + Returns: + FrozenEvent + """ + + # There's currently only the one event version defined + if format_version not in KNOWN_EVENT_FORMAT_VERSIONS: + raise Exception( + "No event format defined for version %r" % (format_version,) + ) + + if internal_metadata_dict is None: + internal_metadata_dict = {} + + time_now = int(clock.time_msec()) + + event_dict["event_id"] = _create_event_id(clock, hostname) + + event_dict["origin"] = hostname + event_dict["origin_server_ts"] = time_now + + event_dict.setdefault("unsigned", {}) + age = event_dict["unsigned"].pop("age", 0) + event_dict["unsigned"].setdefault("age_ts", time_now - age) + + event_dict.setdefault("signatures", {}) + + add_hashes_and_signatures( + event_dict, + hostname, + signing_key, + ) + return event_type_from_format_version(format_version)( + event_dict, internal_metadata_dict=internal_metadata_dict, + ) + + +# A counter used when generating new event IDs +_event_id_counter = 0 + + +def _create_event_id(clock, hostname): + """Create a new event ID + + Args: + clock (Clock) + hostname (str): The server name for the event ID + + Returns: + str + """ - time_now = int(self.clock.time_msec()) + global _event_id_counter - key_values.setdefault("origin", self.hostname) - key_values.setdefault("origin_server_ts", time_now) + i = str(_event_id_counter) + _event_id_counter += 1 - key_values.setdefault("unsigned", {}) - age = key_values["unsigned"].pop("age", 0) - key_values["unsigned"].setdefault("age_ts", time_now - age) + local_part = str(int(clock.time())) + i + random_string(5) - key_values["signatures"] = {} + e_id = EventID(local_part, hostname) - return EventBuilder(key_values=key_values,) + return e_id.to_string() diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py index 71809893c5..be3bb59431 100644 --- a/synapse/federation/federation_client.py +++ b/synapse/federation/federation_client.py @@ -37,8 +37,7 @@ from synapse.api.errors import ( HttpResponseException, SynapseError, ) -from synapse.crypto.event_signing import add_hashes_and_signatures -from synapse.events import room_version_to_event_format +from synapse.events import builder, room_version_to_event_format from synapse.federation.federation_base import FederationBase, event_from_pdu_json from synapse.util import logcontext, unwrapFirstError from synapse.util.caches.expiringcache import ExpiringCache @@ -72,7 +71,8 @@ class FederationClient(FederationBase): self.state = hs.get_state_handler() self.transport_layer = hs.get_federation_transport_client() - self.event_builder_factory = hs.get_event_builder_factory() + self.hostname = hs.hostname + self.signing_key = hs.config.signing_key[0] self._get_pdu_cache = ExpiringCache( cache_name="get_pdu_cache", @@ -608,18 +608,10 @@ class FederationClient(FederationBase): if "prev_state" not in pdu_dict: pdu_dict["prev_state"] = [] - # Strip off the fields that we want to clobber. - pdu_dict.pop("origin", None) - pdu_dict.pop("origin_server_ts", None) - pdu_dict.pop("unsigned", None) - - builder = self.event_builder_factory.new(room_version, pdu_dict) - add_hashes_and_signatures( - builder, - self.hs.hostname, - self.hs.config.signing_key[0] + ev = builder.create_local_event_from_event_dict( + self._clock, self.hostname, self.signing_key, + format_version=event_format, event_dict=pdu_dict, ) - ev = builder.build() defer.returnValue( (destination, ev, event_format) diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py index 05d1370c18..ac6f4fd985 100644 --- a/synapse/handlers/message.py +++ b/synapse/handlers/message.py @@ -22,7 +22,7 @@ from canonicaljson import encode_canonical_json, json from twisted.internet import defer from twisted.internet.defer import succeed -from synapse.api.constants import MAX_DEPTH, EventTypes, Membership, RoomVersions +from synapse.api.constants import EventTypes, Membership, RoomVersions from synapse.api.errors import ( AuthError, Codes, @@ -31,7 +31,6 @@ from synapse.api.errors import ( SynapseError, ) from synapse.api.urls import ConsentURIBuilder -from synapse.crypto.event_signing import add_hashes_and_signatures from synapse.events.utils import serialize_event from synapse.events.validator import EventValidator from synapse.replication.http.send_event import ReplicationSendEventRestServlet @@ -545,40 +544,17 @@ class EventCreationHandler(object): prev_events_and_hashes = \ yield self.store.get_prev_events_for_room(builder.room_id) - if prev_events_and_hashes: - depth = max([d for _, _, d in prev_events_and_hashes]) + 1 - # we cap depth of generated events, to ensure that they are not - # rejected by other servers (and so that they can be persisted in - # the db) - depth = min(depth, MAX_DEPTH) - else: - depth = 1 - prev_events = [ (event_id, prev_hashes) for event_id, prev_hashes, _ in prev_events_and_hashes ] - builder.prev_events = prev_events - builder.depth = depth - - context = yield self.state.compute_event_context(builder) - if requester: - context.app_service = requester.app_service - - if builder.is_state(): - builder.prev_state = yield self.store.add_event_hashes( - context.prev_state_events - ) - - yield self.auth.add_auth_events(builder, context) - - signing_key = self.hs.config.signing_key[0] - add_hashes_and_signatures( - builder, self.server_name, signing_key + event = yield builder.build( + prev_event_ids=[p for p, _ in prev_events], ) + context = yield self.state.compute_event_context(event) - event = builder.build() + self.validator.validate_new(event) logger.debug( "Created event %s", diff --git a/synapse/server.py b/synapse/server.py index c8914302cf..6c52101616 100644 --- a/synapse/server.py +++ b/synapse/server.py @@ -355,10 +355,7 @@ class HomeServer(object): return Keyring(self) def build_event_builder_factory(self): - return EventBuilderFactory( - clock=self.get_clock(), - hostname=self.hostname, - ) + return EventBuilderFactory(self) def build_filtering(self): return Filtering(self) diff --git a/synapse/storage/event_federation.py b/synapse/storage/event_federation.py index d3b9dea1d6..38809ed0fc 100644 --- a/synapse/storage/event_federation.py +++ b/synapse/storage/event_federation.py @@ -125,6 +125,29 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, return dict(txn) + @defer.inlineCallbacks + def get_max_depth_of(self, event_ids): + """Returns the max depth of a set of event IDs + + Args: + event_ids (list[str]) + + Returns + Deferred[int] + """ + rows = yield self._simple_select_many_batch( + table="events", + column="event_id", + iterable=event_ids, + retcols=("depth",), + desc="get_max_depth_of", + ) + + if not rows: + defer.returnValue(0) + else: + defer.returnValue(max(row["depth"] for row in rows)) + def _get_oldest_events_in_room_txn(self, txn, room_id): return self._simple_select_onecol_txn( txn, -- cgit 1.4.1