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-rw-r--r--synapse/handlers/events.py3
-rw-r--r--synapse/handlers/federation.py348
-rw-r--r--synapse/handlers/message.py19
-rw-r--r--synapse/handlers/presence.py110
-rw-r--r--synapse/handlers/profile.py13
-rw-r--r--synapse/handlers/register.py2
-rw-r--r--synapse/handlers/room.py9
-rw-r--r--synapse/handlers/stats.py333
-rw-r--r--synapse/handlers/sync.py43
9 files changed, 677 insertions, 203 deletions
diff --git a/synapse/handlers/events.py b/synapse/handlers/events.py
index 6003ad9cca..eb525070cf 100644
--- a/synapse/handlers/events.py
+++ b/synapse/handlers/events.py
@@ -122,6 +122,9 @@ class EventStreamHandler(BaseHandler):
 
             chunks = yield self._event_serializer.serialize_events(
                 events, time_now, as_client_event=as_client_event,
+                # We don't bundle "live" events, as otherwise clients
+                # will end up double counting annotations.
+                bundle_aggregations=False,
             )
 
             chunk = {
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 0684778882..ac5ca79143 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -35,6 +35,7 @@ from synapse.api.errors import (
     CodeMessageException,
     FederationDeniedError,
     FederationError,
+    RequestSendFailed,
     StoreError,
     SynapseError,
 )
@@ -1916,6 +1917,11 @@ class FederationHandler(BaseHandler):
                     event.room_id, latest_event_ids=extrem_ids,
                 )
 
+            logger.debug(
+                "Doing soft-fail check for %s: state %s",
+                event.event_id, current_state_ids,
+            )
+
             # Now check if event pass auth against said current state
             auth_types = auth_types_for_event(event)
             current_state_ids = [
@@ -1932,7 +1938,7 @@ class FederationHandler(BaseHandler):
                 self.auth.check(room_version, event, auth_events=current_auth_events)
             except AuthError as e:
                 logger.warn(
-                    "Failed current state auth resolution for %r because %s",
+                    "Soft-failing %r because %s",
                     event, e,
                 )
                 event.internal_metadata.soft_failed = True
@@ -2008,15 +2014,65 @@ class FederationHandler(BaseHandler):
 
         Args:
             origin (str):
-            event (synapse.events.FrozenEvent):
+            event (synapse.events.EventBase):
             context (synapse.events.snapshot.EventContext):
-            auth_events (dict[(str, str)->str]):
+            auth_events (dict[(str, str)->synapse.events.EventBase]):
+                Map from (event_type, state_key) to event
+
+                What we expect the event's auth_events to be, based on the event's
+                position in the dag. I think? maybe??
+
+                Also NB that this function adds entries to it.
+        Returns:
+            defer.Deferred[None]
+        """
+        room_version = yield self.store.get_room_version(event.room_id)
+
+        try:
+            yield self._update_auth_events_and_context_for_auth(
+                origin, event, context, auth_events
+            )
+        except Exception:
+            # We don't really mind if the above fails, so lets not fail
+            # processing if it does. However, it really shouldn't fail so
+            # let's still log as an exception since we'll still want to fix
+            # any bugs.
+            logger.exception(
+                "Failed to double check auth events for %s with remote. "
+                "Ignoring failure and continuing processing of event.",
+                event.event_id,
+            )
+
+        try:
+            self.auth.check(room_version, event, auth_events=auth_events)
+        except AuthError as e:
+            logger.warn("Failed auth resolution for %r because %s", event, e)
+            raise e
+
+    @defer.inlineCallbacks
+    def _update_auth_events_and_context_for_auth(
+        self, origin, event, context, auth_events
+    ):
+        """Helper for do_auth. See there for docs.
+
+        Checks whether a given event has the expected auth events. If it
+        doesn't then we talk to the remote server to compare state to see if
+        we can come to a consensus (e.g. if one server missed some valid
+        state).
+
+        This attempts to resovle any potential divergence of state between
+        servers, but is not essential and so failures should not block further
+        processing of the event.
+
+        Args:
+            origin (str):
+            event (synapse.events.EventBase):
+            context (synapse.events.snapshot.EventContext):
+            auth_events (dict[(str, str)->synapse.events.EventBase]):
 
         Returns:
             defer.Deferred[None]
         """
-        # Check if we have all the auth events.
-        current_state = set(e.event_id for e in auth_events.values())
         event_auth_events = set(event.auth_event_ids())
 
         if event.is_state():
@@ -2024,11 +2080,21 @@ class FederationHandler(BaseHandler):
         else:
             event_key = None
 
-        if event_auth_events - current_state:
+        # if the event's auth_events refers to events which are not in our
+        # calculated auth_events, we need to fetch those events from somewhere.
+        #
+        # we start by fetching them from the store, and then try calling /event_auth/.
+        missing_auth = event_auth_events.difference(
+            e.event_id for e in auth_events.values()
+        )
+
+        if missing_auth:
             # TODO: can we use store.have_seen_events here instead?
             have_events = yield self.store.get_seen_events_with_rejections(
-                event_auth_events - current_state
+                missing_auth
             )
+            logger.debug("Got events %s from store", have_events)
+            missing_auth.difference_update(have_events.keys())
         else:
             have_events = {}
 
@@ -2037,17 +2103,22 @@ class FederationHandler(BaseHandler):
             for e in auth_events.values()
         })
 
-        seen_events = set(have_events.keys())
-
-        missing_auth = event_auth_events - seen_events - current_state
-
         if missing_auth:
-            logger.info("Missing auth: %s", missing_auth)
             # If we don't have all the auth events, we need to get them.
+            logger.info(
+                "auth_events contains unknown events: %s",
+                missing_auth,
+            )
             try:
-                remote_auth_chain = yield self.federation_client.get_event_auth(
-                    origin, event.room_id, event.event_id
-                )
+                try:
+                    remote_auth_chain = yield self.federation_client.get_event_auth(
+                        origin, event.room_id, event.event_id
+                    )
+                except RequestSendFailed as e:
+                    # The other side isn't around or doesn't implement the
+                    # endpoint, so lets just bail out.
+                    logger.info("Failed to get event auth from remote: %s", e)
+                    return
 
                 seen_remotes = yield self.store.have_seen_events(
                     [e.event_id for e in remote_auth_chain]
@@ -2084,145 +2155,174 @@ class FederationHandler(BaseHandler):
                 have_events = yield self.store.get_seen_events_with_rejections(
                     event.auth_event_ids()
                 )
-                seen_events = set(have_events.keys())
             except Exception:
                 # FIXME:
                 logger.exception("Failed to get auth chain")
 
+        if event.internal_metadata.is_outlier():
+            logger.info("Skipping auth_event fetch for outlier")
+            return
+
         # FIXME: Assumes we have and stored all the state for all the
         # prev_events
-        current_state = set(e.event_id for e in auth_events.values())
-        different_auth = event_auth_events - current_state
+        different_auth = event_auth_events.difference(
+            e.event_id for e in auth_events.values()
+        )
 
-        room_version = yield self.store.get_room_version(event.room_id)
+        if not different_auth:
+            return
 
-        if different_auth and not event.internal_metadata.is_outlier():
-            # Do auth conflict res.
-            logger.info("Different auth: %s", different_auth)
-
-            different_events = yield logcontext.make_deferred_yieldable(
-                defer.gatherResults([
-                    logcontext.run_in_background(
-                        self.store.get_event,
-                        d,
-                        allow_none=True,
-                        allow_rejected=False,
-                    )
-                    for d in different_auth
-                    if d in have_events and not have_events[d]
-                ], consumeErrors=True)
-            ).addErrback(unwrapFirstError)
-
-            if different_events:
-                local_view = dict(auth_events)
-                remote_view = dict(auth_events)
-                remote_view.update({
-                    (d.type, d.state_key): d for d in different_events if d
-                })
+        logger.info(
+            "auth_events refers to events which are not in our calculated auth "
+            "chain: %s",
+            different_auth,
+        )
+
+        room_version = yield self.store.get_room_version(event.room_id)
 
-                new_state = yield self.state_handler.resolve_events(
-                    room_version,
-                    [list(local_view.values()), list(remote_view.values())],
-                    event
+        different_events = yield logcontext.make_deferred_yieldable(
+            defer.gatherResults([
+                logcontext.run_in_background(
+                    self.store.get_event,
+                    d,
+                    allow_none=True,
+                    allow_rejected=False,
                 )
+                for d in different_auth
+                if d in have_events and not have_events[d]
+            ], consumeErrors=True)
+        ).addErrback(unwrapFirstError)
+
+        if different_events:
+            local_view = dict(auth_events)
+            remote_view = dict(auth_events)
+            remote_view.update({
+                (d.type, d.state_key): d for d in different_events if d
+            })
 
-                auth_events.update(new_state)
+            new_state = yield self.state_handler.resolve_events(
+                room_version,
+                [list(local_view.values()), list(remote_view.values())],
+                event
+            )
 
-                current_state = set(e.event_id for e in auth_events.values())
-                different_auth = event_auth_events - current_state
+            logger.info(
+                "After state res: updating auth_events with new state %s",
+                {
+                    (d.type, d.state_key): d.event_id for d in new_state.values()
+                    if auth_events.get((d.type, d.state_key)) != d
+                },
+            )
 
-                yield self._update_context_for_auth_events(
-                    event, context, auth_events, event_key,
-                )
+            auth_events.update(new_state)
 
-        if different_auth and not event.internal_metadata.is_outlier():
-            logger.info("Different auth after resolution: %s", different_auth)
+            different_auth = event_auth_events.difference(
+                e.event_id for e in auth_events.values()
+            )
 
-            # Only do auth resolution if we have something new to say.
-            # We can't rove an auth failure.
-            do_resolution = False
+            yield self._update_context_for_auth_events(
+                event, context, auth_events, event_key,
+            )
 
-            provable = [
-                RejectedReason.NOT_ANCESTOR, RejectedReason.NOT_ANCESTOR,
-            ]
+        if not different_auth:
+            # we're done
+            return
 
-            for e_id in different_auth:
-                if e_id in have_events:
-                    if have_events[e_id] in provable:
-                        do_resolution = True
-                        break
+        logger.info(
+            "auth_events still refers to events which are not in the calculated auth "
+            "chain after state resolution: %s",
+            different_auth,
+        )
 
-            if do_resolution:
-                prev_state_ids = yield context.get_prev_state_ids(self.store)
-                # 1. Get what we think is the auth chain.
-                auth_ids = yield self.auth.compute_auth_events(
-                    event, prev_state_ids
-                )
-                local_auth_chain = yield self.store.get_auth_chain(
-                    auth_ids, include_given=True
-                )
+        # Only do auth resolution if we have something new to say.
+        # We can't prove an auth failure.
+        do_resolution = False
 
-                try:
-                    # 2. Get remote difference.
-                    result = yield self.federation_client.query_auth(
-                        origin,
-                        event.room_id,
-                        event.event_id,
-                        local_auth_chain,
-                    )
+        for e_id in different_auth:
+            if e_id in have_events:
+                if have_events[e_id] == RejectedReason.NOT_ANCESTOR:
+                    do_resolution = True
+                    break
 
-                    seen_remotes = yield self.store.have_seen_events(
-                        [e.event_id for e in result["auth_chain"]]
-                    )
+        if not do_resolution:
+            logger.info(
+                "Skipping auth resolution due to lack of provable rejection reasons"
+            )
+            return
 
-                    # 3. Process any remote auth chain events we haven't seen.
-                    for ev in result["auth_chain"]:
-                        if ev.event_id in seen_remotes:
-                            continue
+        logger.info("Doing auth resolution")
 
-                        if ev.event_id == event.event_id:
-                            continue
+        prev_state_ids = yield context.get_prev_state_ids(self.store)
 
-                        try:
-                            auth_ids = ev.auth_event_ids()
-                            auth = {
-                                (e.type, e.state_key): e
-                                for e in result["auth_chain"]
-                                if e.event_id in auth_ids
-                                or event.type == EventTypes.Create
-                            }
-                            ev.internal_metadata.outlier = True
+        # 1. Get what we think is the auth chain.
+        auth_ids = yield self.auth.compute_auth_events(
+            event, prev_state_ids
+        )
+        local_auth_chain = yield self.store.get_auth_chain(
+            auth_ids, include_given=True
+        )
 
-                            logger.debug(
-                                "do_auth %s different_auth: %s",
-                                event.event_id, e.event_id
-                            )
+        try:
+            # 2. Get remote difference.
+            try:
+                result = yield self.federation_client.query_auth(
+                    origin,
+                    event.room_id,
+                    event.event_id,
+                    local_auth_chain,
+                )
+            except RequestSendFailed as e:
+                # The other side isn't around or doesn't implement the
+                # endpoint, so lets just bail out.
+                logger.info("Failed to query auth from remote: %s", e)
+                return
+
+            seen_remotes = yield self.store.have_seen_events(
+                [e.event_id for e in result["auth_chain"]]
+            )
 
-                            yield self._handle_new_event(
-                                origin, ev, auth_events=auth
-                            )
+            # 3. Process any remote auth chain events we haven't seen.
+            for ev in result["auth_chain"]:
+                if ev.event_id in seen_remotes:
+                    continue
 
-                            if ev.event_id in event_auth_events:
-                                auth_events[(ev.type, ev.state_key)] = ev
-                        except AuthError:
-                            pass
+                if ev.event_id == event.event_id:
+                    continue
 
-                except Exception:
-                    # FIXME:
-                    logger.exception("Failed to query auth chain")
+                try:
+                    auth_ids = ev.auth_event_ids()
+                    auth = {
+                        (e.type, e.state_key): e
+                        for e in result["auth_chain"]
+                        if e.event_id in auth_ids
+                        or event.type == EventTypes.Create
+                    }
+                    ev.internal_metadata.outlier = True
+
+                    logger.debug(
+                        "do_auth %s different_auth: %s",
+                        event.event_id, e.event_id
+                    )
 
-                # 4. Look at rejects and their proofs.
-                # TODO.
+                    yield self._handle_new_event(
+                        origin, ev, auth_events=auth
+                    )
 
-                yield self._update_context_for_auth_events(
-                    event, context, auth_events, event_key,
-                )
+                    if ev.event_id in event_auth_events:
+                        auth_events[(ev.type, ev.state_key)] = ev
+                except AuthError:
+                    pass
 
-        try:
-            self.auth.check(room_version, event, auth_events=auth_events)
-        except AuthError as e:
-            logger.warn("Failed auth resolution for %r because %s", event, e)
-            raise e
+        except Exception:
+            # FIXME:
+            logger.exception("Failed to query auth chain")
+
+        # 4. Look at rejects and their proofs.
+        # TODO.
+
+        yield self._update_context_for_auth_events(
+            event, context, auth_events, event_key,
+        )
 
     @defer.inlineCallbacks
     def _update_context_for_auth_events(self, event, context, auth_events,
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 7b2c33a922..0b02469ceb 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 EventTypes, Membership
+from synapse.api.constants import EventTypes, Membership, RelationTypes
 from synapse.api.errors import (
     AuthError,
     Codes,
@@ -166,6 +166,9 @@ class MessageHandler(object):
         now = self.clock.time_msec()
         events = yield self._event_serializer.serialize_events(
             room_state.values(), now,
+            # We don't bother bundling aggregations in when asked for state
+            # events, as clients won't use them.
+            bundle_aggregations=False,
         )
         defer.returnValue(events)
 
@@ -601,6 +604,20 @@ class EventCreationHandler(object):
 
         self.validator.validate_new(event)
 
+        # If this event is an annotation then we check that that the sender
+        # can't annotate the same way twice (e.g. stops users from liking an
+        # event multiple times).
+        relation = event.content.get("m.relates_to", {})
+        if relation.get("rel_type") == RelationTypes.ANNOTATION:
+            relates_to = relation["event_id"]
+            aggregation_key = relation["key"]
+
+            already_exists = yield self.store.has_user_annotated_event(
+                relates_to, event.type, aggregation_key, event.sender,
+            )
+            if already_exists:
+                raise SynapseError(400, "Can't send same reaction twice")
+
         logger.debug(
             "Created event %s",
             event.event_id,
diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index 59d53f1050..e49c8203ef 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -182,17 +182,27 @@ class PresenceHandler(object):
         # Start a LoopingCall in 30s that fires every 5s.
         # The initial delay is to allow disconnected clients a chance to
         # reconnect before we treat them as offline.
+        def run_timeout_handler():
+            return run_as_background_process(
+                "handle_presence_timeouts", self._handle_timeouts
+            )
+
         self.clock.call_later(
             30,
             self.clock.looping_call,
-            self._handle_timeouts,
+            run_timeout_handler,
             5000,
         )
 
+        def run_persister():
+            return run_as_background_process(
+                "persist_presence_changes", self._persist_unpersisted_changes
+            )
+
         self.clock.call_later(
             60,
             self.clock.looping_call,
-            self._persist_unpersisted_changes,
+            run_persister,
             60 * 1000,
         )
 
@@ -229,6 +239,7 @@ class PresenceHandler(object):
         )
 
         if self.unpersisted_users_changes:
+
             yield self.store.update_presence([
                 self.user_to_current_state[user_id]
                 for user_id in self.unpersisted_users_changes
@@ -240,30 +251,18 @@ class PresenceHandler(object):
         """We periodically persist the unpersisted changes, as otherwise they
         may stack up and slow down shutdown times.
         """
-        logger.info(
-            "Performing _persist_unpersisted_changes. Persisting %d unpersisted changes",
-            len(self.unpersisted_users_changes)
-        )
-
         unpersisted = self.unpersisted_users_changes
         self.unpersisted_users_changes = set()
 
         if unpersisted:
+            logger.info(
+                "Persisting %d upersisted presence updates", len(unpersisted)
+            )
             yield self.store.update_presence([
                 self.user_to_current_state[user_id]
                 for user_id in unpersisted
             ])
 
-        logger.info("Finished _persist_unpersisted_changes")
-
-    @defer.inlineCallbacks
-    def _update_states_and_catch_exception(self, new_states):
-        try:
-            res = yield self._update_states(new_states)
-            defer.returnValue(res)
-        except Exception:
-            logger.exception("Error updating presence")
-
     @defer.inlineCallbacks
     def _update_states(self, new_states):
         """Updates presence of users. Sets the appropriate timeouts. Pokes
@@ -338,45 +337,41 @@ class PresenceHandler(object):
         logger.info("Handling presence timeouts")
         now = self.clock.time_msec()
 
-        try:
-            with Measure(self.clock, "presence_handle_timeouts"):
-                # Fetch the list of users that *may* have timed out. Things may have
-                # changed since the timeout was set, so we won't necessarily have to
-                # take any action.
-                users_to_check = set(self.wheel_timer.fetch(now))
-
-                # Check whether the lists of syncing processes from an external
-                # process have expired.
-                expired_process_ids = [
-                    process_id for process_id, last_update
-                    in self.external_process_last_updated_ms.items()
-                    if now - last_update > EXTERNAL_PROCESS_EXPIRY
-                ]
-                for process_id in expired_process_ids:
-                    users_to_check.update(
-                        self.external_process_last_updated_ms.pop(process_id, ())
-                    )
-                    self.external_process_last_update.pop(process_id)
+        # Fetch the list of users that *may* have timed out. Things may have
+        # changed since the timeout was set, so we won't necessarily have to
+        # take any action.
+        users_to_check = set(self.wheel_timer.fetch(now))
+
+        # Check whether the lists of syncing processes from an external
+        # process have expired.
+        expired_process_ids = [
+            process_id for process_id, last_update
+            in self.external_process_last_updated_ms.items()
+            if now - last_update > EXTERNAL_PROCESS_EXPIRY
+        ]
+        for process_id in expired_process_ids:
+            users_to_check.update(
+                self.external_process_last_updated_ms.pop(process_id, ())
+            )
+            self.external_process_last_update.pop(process_id)
 
-                states = [
-                    self.user_to_current_state.get(
-                        user_id, UserPresenceState.default(user_id)
-                    )
-                    for user_id in users_to_check
-                ]
+        states = [
+            self.user_to_current_state.get(
+                user_id, UserPresenceState.default(user_id)
+            )
+            for user_id in users_to_check
+        ]
 
-                timers_fired_counter.inc(len(states))
+        timers_fired_counter.inc(len(states))
 
-                changes = handle_timeouts(
-                    states,
-                    is_mine_fn=self.is_mine_id,
-                    syncing_user_ids=self.get_currently_syncing_users(),
-                    now=now,
-                )
+        changes = handle_timeouts(
+            states,
+            is_mine_fn=self.is_mine_id,
+            syncing_user_ids=self.get_currently_syncing_users(),
+            now=now,
+        )
 
-            run_in_background(self._update_states_and_catch_exception, changes)
-        except Exception:
-            logger.exception("Exception in _handle_timeouts loop")
+        return self._update_states(changes)
 
     @defer.inlineCallbacks
     def bump_presence_active_time(self, user):
@@ -833,14 +828,17 @@ class PresenceHandler(object):
                 # joins.
                 continue
 
-            event = yield self.store.get_event(event_id)
-            if event.content.get("membership") != Membership.JOIN:
+            event = yield self.store.get_event(event_id, allow_none=True)
+            if not event or event.content.get("membership") != Membership.JOIN:
                 # We only care about joins
                 continue
 
             if prev_event_id:
-                prev_event = yield self.store.get_event(prev_event_id)
-                if prev_event.content.get("membership") == Membership.JOIN:
+                prev_event = yield self.store.get_event(prev_event_id, allow_none=True)
+                if (
+                    prev_event
+                    and prev_event.content.get("membership") == Membership.JOIN
+                ):
                     # Ignore changes to join events.
                     continue
 
diff --git a/synapse/handlers/profile.py b/synapse/handlers/profile.py
index 91fc718ff8..a5fc6c5dbf 100644
--- a/synapse/handlers/profile.py
+++ b/synapse/handlers/profile.py
@@ -31,6 +31,9 @@ from ._base import BaseHandler
 
 logger = logging.getLogger(__name__)
 
+MAX_DISPLAYNAME_LEN = 100
+MAX_AVATAR_URL_LEN = 1000
+
 
 class BaseProfileHandler(BaseHandler):
     """Handles fetching and updating user profile information.
@@ -162,6 +165,11 @@ class BaseProfileHandler(BaseHandler):
         if not by_admin and target_user != requester.user:
             raise AuthError(400, "Cannot set another user's displayname")
 
+        if len(new_displayname) > MAX_DISPLAYNAME_LEN:
+            raise SynapseError(
+                400, "Displayname is too long (max %i)" % (MAX_DISPLAYNAME_LEN, ),
+            )
+
         if new_displayname == '':
             new_displayname = None
 
@@ -217,6 +225,11 @@ class BaseProfileHandler(BaseHandler):
         if not by_admin and target_user != requester.user:
             raise AuthError(400, "Cannot set another user's avatar_url")
 
+        if len(new_avatar_url) > MAX_AVATAR_URL_LEN:
+            raise SynapseError(
+                400, "Avatar URL is too long (max %i)" % (MAX_AVATAR_URL_LEN, ),
+            )
+
         yield self.store.set_profile_avatar_url(
             target_user.localpart, new_avatar_url
         )
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index e83ee24f10..9a388ea013 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -531,6 +531,8 @@ class RegistrationHandler(BaseHandler):
             A tuple of (user_id, access_token).
         Raises:
             RegistrationError if there was a problem registering.
+
+        NB this is only used in tests. TODO: move it to the test package!
         """
         if localpart is None:
             raise SynapseError(400, "Request must include user id")
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index e37ae96899..4a17911a87 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -27,7 +27,7 @@ from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, JoinRules, RoomCreationPreset
 from synapse.api.errors import AuthError, Codes, NotFoundError, StoreError, SynapseError
-from synapse.api.room_versions import DEFAULT_ROOM_VERSION, KNOWN_ROOM_VERSIONS
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.storage.state import StateFilter
 from synapse.types import RoomAlias, RoomID, RoomStreamToken, StreamToken, UserID
 from synapse.util import stringutils
@@ -70,6 +70,7 @@ class RoomCreationHandler(BaseHandler):
         self.spam_checker = hs.get_spam_checker()
         self.event_creation_handler = hs.get_event_creation_handler()
         self.room_member_handler = hs.get_room_member_handler()
+        self.config = hs.config
 
         # linearizer to stop two upgrades happening at once
         self._upgrade_linearizer = Linearizer("room_upgrade_linearizer")
@@ -475,7 +476,11 @@ class RoomCreationHandler(BaseHandler):
         if ratelimit:
             yield self.ratelimit(requester)
 
-        room_version = config.get("room_version", DEFAULT_ROOM_VERSION.identifier)
+        room_version = config.get(
+            "room_version",
+            self.config.default_room_version.identifier,
+        )
+
         if not isinstance(room_version, string_types):
             raise SynapseError(
                 400,
diff --git a/synapse/handlers/stats.py b/synapse/handlers/stats.py
new file mode 100644
index 0000000000..7ad16c8566
--- /dev/null
+++ b/synapse/handlers/stats.py
@@ -0,0 +1,333 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector Ltd
+#
+# 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 logging
+
+from twisted.internet import defer
+
+from synapse.api.constants import EventTypes, JoinRules, Membership
+from synapse.handlers.state_deltas import StateDeltasHandler
+from synapse.metrics import event_processing_positions
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.types import UserID
+from synapse.util.metrics import Measure
+
+logger = logging.getLogger(__name__)
+
+
+class StatsHandler(StateDeltasHandler):
+    """Handles keeping the *_stats tables updated with a simple time-series of
+    information about the users, rooms and media on the server, such that admins
+    have some idea of who is consuming their resources.
+
+    Heavily derived from UserDirectoryHandler
+    """
+
+    def __init__(self, hs):
+        super(StatsHandler, self).__init__(hs)
+        self.hs = hs
+        self.store = hs.get_datastore()
+        self.state = hs.get_state_handler()
+        self.server_name = hs.hostname
+        self.clock = hs.get_clock()
+        self.notifier = hs.get_notifier()
+        self.is_mine_id = hs.is_mine_id
+        self.stats_bucket_size = hs.config.stats_bucket_size
+
+        # The current position in the current_state_delta stream
+        self.pos = None
+
+        # Guard to ensure we only process deltas one at a time
+        self._is_processing = False
+
+        if hs.config.stats_enabled:
+            self.notifier.add_replication_callback(self.notify_new_event)
+
+            # We kick this off so that we don't have to wait for a change before
+            # we start populating stats
+            self.clock.call_later(0, self.notify_new_event)
+
+    def notify_new_event(self):
+        """Called when there may be more deltas to process
+        """
+        if not self.hs.config.stats_enabled:
+            return
+
+        if self._is_processing:
+            return
+
+        @defer.inlineCallbacks
+        def process():
+            try:
+                yield self._unsafe_process()
+            finally:
+                self._is_processing = False
+
+        self._is_processing = True
+        run_as_background_process("stats.notify_new_event", process)
+
+    @defer.inlineCallbacks
+    def _unsafe_process(self):
+        # If self.pos is None then means we haven't fetched it from DB
+        if self.pos is None:
+            self.pos = yield self.store.get_stats_stream_pos()
+
+        # If still None then the initial background update hasn't happened yet
+        if self.pos is None:
+            defer.returnValue(None)
+
+        # Loop round handling deltas until we're up to date
+        while True:
+            with Measure(self.clock, "stats_delta"):
+                deltas = yield self.store.get_current_state_deltas(self.pos)
+                if not deltas:
+                    return
+
+                logger.info("Handling %d state deltas", len(deltas))
+                yield self._handle_deltas(deltas)
+
+                self.pos = deltas[-1]["stream_id"]
+                yield self.store.update_stats_stream_pos(self.pos)
+
+                event_processing_positions.labels("stats").set(self.pos)
+
+    @defer.inlineCallbacks
+    def _handle_deltas(self, deltas):
+        """
+        Called with the state deltas to process
+        """
+        for delta in deltas:
+            typ = delta["type"]
+            state_key = delta["state_key"]
+            room_id = delta["room_id"]
+            event_id = delta["event_id"]
+            stream_id = delta["stream_id"]
+            prev_event_id = delta["prev_event_id"]
+            stream_pos = delta["stream_id"]
+
+            logger.debug("Handling: %r %r, %s", typ, state_key, event_id)
+
+            token = yield self.store.get_earliest_token_for_room_stats(room_id)
+
+            # If the earliest token to begin from is larger than our current
+            # stream ID, skip processing this delta.
+            if token is not None and token >= stream_id:
+                logger.debug(
+                    "Ignoring: %s as earlier than this room's initial ingestion event",
+                    event_id,
+                )
+                continue
+
+            if event_id is None and prev_event_id is None:
+                # Errr...
+                continue
+
+            event_content = {}
+
+            if event_id is not None:
+                event = yield self.store.get_event(event_id, allow_none=True)
+                if event:
+                    event_content = event.content or {}
+
+            # We use stream_pos here rather than fetch by event_id as event_id
+            # may be None
+            now = yield self.store.get_received_ts_by_stream_pos(stream_pos)
+
+            # quantise time to the nearest bucket
+            now = (now // 1000 // self.stats_bucket_size) * self.stats_bucket_size
+
+            if typ == EventTypes.Member:
+                # we could use _get_key_change here but it's a bit inefficient
+                # given we're not testing for a specific result; might as well
+                # just grab the prev_membership and membership strings and
+                # compare them.
+                prev_event_content = {}
+                if prev_event_id is not None:
+                    prev_event = yield self.store.get_event(
+                        prev_event_id, allow_none=True,
+                    )
+                    if prev_event:
+                        prev_event_content = prev_event.content
+
+                membership = event_content.get("membership", Membership.LEAVE)
+                prev_membership = prev_event_content.get("membership", Membership.LEAVE)
+
+                if prev_membership == membership:
+                    continue
+
+                if prev_membership == Membership.JOIN:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "joined_members", -1
+                    )
+                elif prev_membership == Membership.INVITE:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "invited_members", -1
+                    )
+                elif prev_membership == Membership.LEAVE:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "left_members", -1
+                    )
+                elif prev_membership == Membership.BAN:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "banned_members", -1
+                    )
+                else:
+                    err = "%s is not a valid prev_membership" % (repr(prev_membership),)
+                    logger.error(err)
+                    raise ValueError(err)
+
+                if membership == Membership.JOIN:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "joined_members", +1
+                    )
+                elif membership == Membership.INVITE:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "invited_members", +1
+                    )
+                elif membership == Membership.LEAVE:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "left_members", +1
+                    )
+                elif membership == Membership.BAN:
+                    yield self.store.update_stats_delta(
+                        now, "room", room_id, "banned_members", +1
+                    )
+                else:
+                    err = "%s is not a valid membership" % (repr(membership),)
+                    logger.error(err)
+                    raise ValueError(err)
+
+                user_id = state_key
+                if self.is_mine_id(user_id):
+                    # update user_stats as it's one of our users
+                    public = yield self._is_public_room(room_id)
+
+                    if membership == Membership.LEAVE:
+                        yield self.store.update_stats_delta(
+                            now,
+                            "user",
+                            user_id,
+                            "public_rooms" if public else "private_rooms",
+                            -1,
+                        )
+                    elif membership == Membership.JOIN:
+                        yield self.store.update_stats_delta(
+                            now,
+                            "user",
+                            user_id,
+                            "public_rooms" if public else "private_rooms",
+                            +1,
+                        )
+
+            elif typ == EventTypes.Create:
+                # Newly created room. Add it with all blank portions.
+                yield self.store.update_room_state(
+                    room_id,
+                    {
+                        "join_rules": None,
+                        "history_visibility": None,
+                        "encryption": None,
+                        "name": None,
+                        "topic": None,
+                        "avatar": None,
+                        "canonical_alias": None,
+                    },
+                )
+
+            elif typ == EventTypes.JoinRules:
+                yield self.store.update_room_state(
+                    room_id, {"join_rules": event_content.get("join_rule")}
+                )
+
+                is_public = yield self._get_key_change(
+                    prev_event_id, event_id, "join_rule", JoinRules.PUBLIC
+                )
+                if is_public is not None:
+                    yield self.update_public_room_stats(now, room_id, is_public)
+
+            elif typ == EventTypes.RoomHistoryVisibility:
+                yield self.store.update_room_state(
+                    room_id,
+                    {"history_visibility": event_content.get("history_visibility")},
+                )
+
+                is_public = yield self._get_key_change(
+                    prev_event_id, event_id, "history_visibility", "world_readable"
+                )
+                if is_public is not None:
+                    yield self.update_public_room_stats(now, room_id, is_public)
+
+            elif typ == EventTypes.Encryption:
+                yield self.store.update_room_state(
+                    room_id, {"encryption": event_content.get("algorithm")}
+                )
+            elif typ == EventTypes.Name:
+                yield self.store.update_room_state(
+                    room_id, {"name": event_content.get("name")}
+                )
+            elif typ == EventTypes.Topic:
+                yield self.store.update_room_state(
+                    room_id, {"topic": event_content.get("topic")}
+                )
+            elif typ == EventTypes.RoomAvatar:
+                yield self.store.update_room_state(
+                    room_id, {"avatar": event_content.get("url")}
+                )
+            elif typ == EventTypes.CanonicalAlias:
+                yield self.store.update_room_state(
+                    room_id, {"canonical_alias": event_content.get("alias")}
+                )
+
+    @defer.inlineCallbacks
+    def update_public_room_stats(self, ts, room_id, is_public):
+        """
+        Increment/decrement a user's number of public rooms when a room they are
+        in changes to/from public visibility.
+
+        Args:
+            ts (int): Timestamp in seconds
+            room_id (str)
+            is_public (bool)
+        """
+        # For now, blindly iterate over all local users in the room so that
+        # we can handle the whole problem of copying buckets over as needed
+        user_ids = yield self.store.get_users_in_room(room_id)
+
+        for user_id in user_ids:
+            if self.hs.is_mine(UserID.from_string(user_id)):
+                yield self.store.update_stats_delta(
+                    ts, "user", user_id, "public_rooms", +1 if is_public else -1
+                )
+                yield self.store.update_stats_delta(
+                    ts, "user", user_id, "private_rooms", -1 if is_public else +1
+                )
+
+    @defer.inlineCallbacks
+    def _is_public_room(self, room_id):
+        join_rules = yield self.state.get_current_state(room_id, EventTypes.JoinRules)
+        history_visibility = yield self.state.get_current_state(
+            room_id, EventTypes.RoomHistoryVisibility
+        )
+
+        if (join_rules and join_rules.content.get("join_rule") == JoinRules.PUBLIC) or (
+            (
+                history_visibility
+                and history_visibility.content.get("history_visibility")
+                == "world_readable"
+            )
+        ):
+            defer.returnValue(True)
+        else:
+            defer.returnValue(False)
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 1ee9a6e313..62fda0c664 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -583,30 +583,42 @@ class SyncHandler(object):
         )
 
         # if the room has a name or canonical_alias set, we can skip
-        # calculating heroes.  we assume that if the event has contents, it'll
-        # be a valid name or canonical_alias - i.e. we're checking that they
-        # haven't been "deleted" by blatting {} over the top.
+        # calculating heroes. Empty strings are falsey, so we check
+        # for the "name" value and default to an empty string.
         if name_id:
             name = yield self.store.get_event(name_id, allow_none=True)
-            if name and name.content:
+            if name and name.content.get("name"):
                 defer.returnValue(summary)
 
         if canonical_alias_id:
             canonical_alias = yield self.store.get_event(
                 canonical_alias_id, allow_none=True,
             )
-            if canonical_alias and canonical_alias.content:
+            if canonical_alias and canonical_alias.content.get("alias"):
                 defer.returnValue(summary)
 
+        me = sync_config.user.to_string()
+
         joined_user_ids = [
-            r[0] for r in details.get(Membership.JOIN, empty_ms).members
+            r[0]
+            for r in details.get(Membership.JOIN, empty_ms).members
+            if r[0] != me
         ]
         invited_user_ids = [
-            r[0] for r in details.get(Membership.INVITE, empty_ms).members
+            r[0]
+            for r in details.get(Membership.INVITE, empty_ms).members
+            if r[0] != me
         ]
         gone_user_ids = (
-            [r[0] for r in details.get(Membership.LEAVE, empty_ms).members] +
-            [r[0] for r in details.get(Membership.BAN, empty_ms).members]
+            [
+                r[0]
+                for r in details.get(Membership.LEAVE, empty_ms).members
+                if r[0] != me
+            ] + [
+                r[0]
+                for r in details.get(Membership.BAN, empty_ms).members
+                if r[0] != me
+            ]
         )
 
         # FIXME: only build up a member_ids list for our heroes
@@ -621,22 +633,13 @@ class SyncHandler(object):
                 member_ids[user_id] = event_id
 
         # FIXME: order by stream ordering rather than as returned by SQL
-        me = sync_config.user.to_string()
         if (joined_user_ids or invited_user_ids):
             summary['m.heroes'] = sorted(
-                [
-                    user_id
-                    for user_id in (joined_user_ids + invited_user_ids)
-                    if user_id != me
-                ]
+                [user_id for user_id in (joined_user_ids + invited_user_ids)]
             )[0:5]
         else:
             summary['m.heroes'] = sorted(
-                [
-                    user_id
-                    for user_id in gone_user_ids
-                    if user_id != me
-                ]
+                [user_id for user_id in gone_user_ids]
             )[0:5]
 
         if not sync_config.filter_collection.lazy_load_members():