summary refs log tree commit diff
path: root/synapse/handlers/sync.py
diff options
context:
space:
mode:
Diffstat (limited to 'synapse/handlers/sync.py')
-rw-r--r--synapse/handlers/sync.py705
1 files changed, 468 insertions, 237 deletions
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 353a416054..6dc9d0fb92 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -28,23 +28,30 @@ logger = logging.getLogger(__name__)
 
 SyncConfig = collections.namedtuple("SyncConfig", [
     "user",
-    "client_info",
-    "limit",
-    "gap",
-    "sort",
-    "backfill",
     "filter",
 ])
 
 
-class RoomSyncResult(collections.namedtuple("RoomSyncResult", [
-    "room_id",
-    "limited",
-    "published",
-    "events",
-    "state",
+class TimelineBatch(collections.namedtuple("TimelineBatch", [
     "prev_batch",
+    "events",
+    "limited",
+])):
+    __slots__ = []
+
+    def __nonzero__(self):
+        """Make the result appear empty if there are no updates. This is used
+        to tell if room needs to be part of the sync result.
+        """
+        return bool(self.events)
+
+
+class JoinedSyncResult(collections.namedtuple("JoinedSyncResult", [
+    "room_id",           # str
+    "timeline",          # TimelineBatch
+    "state",             # dict[(str, str), FrozenEvent]
     "ephemeral",
+    "private_user_data",
 ])):
     __slots__ = []
 
@@ -52,14 +59,50 @@ class RoomSyncResult(collections.namedtuple("RoomSyncResult", [
         """Make the result appear empty if there are no updates. This is used
         to tell if room needs to be part of the sync result.
         """
-        return bool(self.events or self.state or self.ephemeral)
+        return bool(
+            self.timeline
+            or self.state
+            or self.ephemeral
+            or self.private_user_data
+        )
+
+
+class ArchivedSyncResult(collections.namedtuple("JoinedSyncResult", [
+    "room_id",            # str
+    "timeline",           # TimelineBatch
+    "state",              # dict[(str, str), FrozenEvent]
+    "private_user_data",
+])):
+    __slots__ = []
+
+    def __nonzero__(self):
+        """Make the result appear empty if there are no updates. This is used
+        to tell if room needs to be part of the sync result.
+        """
+        return bool(
+            self.timeline
+            or self.state
+            or self.private_user_data
+        )
+
+
+class InvitedSyncResult(collections.namedtuple("InvitedSyncResult", [
+    "room_id",   # str
+    "invite",    # FrozenEvent: the invite event
+])):
+    __slots__ = []
+
+    def __nonzero__(self):
+        """Invited rooms should always be reported to the client"""
+        return True
 
 
 class SyncResult(collections.namedtuple("SyncResult", [
     "next_batch",  # Token for the next sync
-    "private_user_data",  # List of private events for the user.
-    "public_user_data",  # List of public events for all users.
-    "rooms",  # RoomSyncResult for each room.
+    "presence",  # List of presence events for the user.
+    "joined",  # JoinedSyncResult for each joined room.
+    "invited",  # InvitedSyncResult for each invited room.
+    "archived",  # ArchivedSyncResult for each archived room.
 ])):
     __slots__ = []
 
@@ -69,7 +112,7 @@ class SyncResult(collections.namedtuple("SyncResult", [
         events.
         """
         return bool(
-            self.private_user_data or self.public_user_data or self.rooms
+            self.presence or self.joined or self.invited
         )
 
 
@@ -81,67 +124,58 @@ class SyncHandler(BaseHandler):
         self.clock = hs.get_clock()
 
     @defer.inlineCallbacks
-    def wait_for_sync_for_user(self, sync_config, since_token=None, timeout=0):
+    def wait_for_sync_for_user(self, sync_config, since_token=None, timeout=0,
+                               full_state=False):
         """Get the sync for a client if we have new data for it now. Otherwise
         wait for new data to arrive on the server. If the timeout expires, then
         return an empty sync result.
         Returns:
             A Deferred SyncResult.
         """
-        if timeout == 0 or since_token is None:
-            result = yield self.current_sync_for_user(sync_config, since_token)
+
+        if timeout == 0 or since_token is None or full_state:
+            # we are going to return immediately, so don't bother calling
+            # notifier.wait_for_events.
+            result = yield self.current_sync_for_user(sync_config, since_token,
+                                                      full_state=full_state)
             defer.returnValue(result)
         else:
             def current_sync_callback(before_token, after_token):
                 return self.current_sync_for_user(sync_config, since_token)
 
-            rm_handler = self.hs.get_handlers().room_member_handler
-
-            app_service = yield self.store.get_app_service_by_user_id(
-                sync_config.user.to_string()
-            )
-            if app_service:
-                rooms = yield self.store.get_app_service_rooms(app_service)
-                room_ids = set(r.room_id for r in rooms)
-            else:
-                room_ids = yield rm_handler.get_joined_rooms_for_user(
-                    sync_config.user
-                )
-
             result = yield self.notifier.wait_for_events(
-                sync_config.user, room_ids,
-                sync_config.filter, timeout, current_sync_callback
+                sync_config.user, timeout, current_sync_callback,
+                from_token=since_token
             )
             defer.returnValue(result)
 
-    def current_sync_for_user(self, sync_config, since_token=None):
+    def current_sync_for_user(self, sync_config, since_token=None,
+                              full_state=False):
         """Get the sync for client needed to match what the server has now.
         Returns:
             A Deferred SyncResult.
         """
-        if since_token is None:
-            return self.initial_sync(sync_config)
+        if since_token is None or full_state:
+            return self.full_state_sync(sync_config, since_token)
         else:
-            if sync_config.gap:
-                return self.incremental_sync_with_gap(sync_config, since_token)
-            else:
-                # TODO(mjark): Handle gapless sync
-                raise NotImplementedError()
+            return self.incremental_sync_with_gap(sync_config, since_token)
 
     @defer.inlineCallbacks
-    def initial_sync(self, sync_config):
-        """Get a sync for a client which is starting without any state
+    def full_state_sync(self, sync_config, timeline_since_token):
+        """Get a sync for a client which is starting without any state.
+
+        If a 'message_since_token' is given, only timeline events which have
+        happened since that token will be returned.
+
         Returns:
             A Deferred SyncResult.
         """
-        if sync_config.sort == "timeline,desc":
-            # TODO(mjark): Handle going through events in reverse order?.
-            # What does "most recent events" mean when applying the limits mean
-            # in this case?
-            raise NotImplementedError()
-
         now_token = yield self.event_sources.get_current_token()
 
+        now_token, ephemeral_by_room = yield self.ephemeral_by_room(
+            sync_config, now_token
+        )
+
         presence_stream = self.event_sources.sources["presence"]
         # TODO (mjark): This looks wrong, shouldn't we be getting the presence
         # UP to the present rather than after the present?
@@ -153,52 +187,179 @@ class SyncHandler(BaseHandler):
         )
         room_list = yield self.store.get_rooms_for_user_where_membership_is(
             user_id=sync_config.user.to_string(),
-            membership_list=[Membership.INVITE, Membership.JOIN]
+            membership_list=(
+                Membership.INVITE,
+                Membership.JOIN,
+                Membership.LEAVE,
+                Membership.BAN
+            )
         )
 
-        # TODO (mjark): Does public mean "published"?
-        published_rooms = yield self.store.get_rooms(is_public=True)
-        published_room_ids = set(r["room_id"] for r in published_rooms)
+        tags_by_room = yield self.store.get_tags_for_user(
+            sync_config.user.to_string()
+        )
 
-        rooms = []
+        joined = []
+        invited = []
+        archived = []
         for event in room_list:
-            room_sync = yield self.initial_sync_for_room(
-                event.room_id, sync_config, now_token, published_room_ids
-            )
-            rooms.append(room_sync)
+            if event.membership == Membership.JOIN:
+                room_sync = yield self.full_state_sync_for_joined_room(
+                    room_id=event.room_id,
+                    sync_config=sync_config,
+                    now_token=now_token,
+                    timeline_since_token=timeline_since_token,
+                    ephemeral_by_room=ephemeral_by_room,
+                    tags_by_room=tags_by_room,
+                )
+                joined.append(room_sync)
+            elif event.membership == Membership.INVITE:
+                invite = yield self.store.get_event(event.event_id)
+                invited.append(InvitedSyncResult(
+                    room_id=event.room_id,
+                    invite=invite,
+                ))
+            elif event.membership in (Membership.LEAVE, Membership.BAN):
+                leave_token = now_token.copy_and_replace(
+                    "room_key", "s%d" % (event.stream_ordering,)
+                )
+                room_sync = yield self.full_state_sync_for_archived_room(
+                    sync_config=sync_config,
+                    room_id=event.room_id,
+                    leave_event_id=event.event_id,
+                    leave_token=leave_token,
+                    timeline_since_token=timeline_since_token,
+                    tags_by_room=tags_by_room,
+                )
+                archived.append(room_sync)
 
         defer.returnValue(SyncResult(
-            public_user_data=presence,
-            private_user_data=[],
-            rooms=rooms,
+            presence=presence,
+            joined=joined,
+            invited=invited,
+            archived=archived,
             next_batch=now_token,
         ))
 
     @defer.inlineCallbacks
-    def initial_sync_for_room(self, room_id, sync_config, now_token,
-                              published_room_ids):
+    def full_state_sync_for_joined_room(self, room_id, sync_config,
+                                        now_token, timeline_since_token,
+                                        ephemeral_by_room, tags_by_room):
         """Sync a room for a client which is starting without any state
         Returns:
-            A Deferred RoomSyncResult.
+            A Deferred JoinedSyncResult.
         """
 
-        recents, prev_batch_token, limited = yield self.load_filtered_recents(
-            room_id, sync_config, now_token,
+        batch = yield self.load_filtered_recents(
+            room_id, sync_config, now_token, since_token=timeline_since_token
         )
 
-        current_state = yield self.state_handler.get_current_state(
-            room_id
+        current_state = yield self.get_state_at(room_id, now_token)
+
+        defer.returnValue(JoinedSyncResult(
+            room_id=room_id,
+            timeline=batch,
+            state=current_state,
+            ephemeral=ephemeral_by_room.get(room_id, []),
+            private_user_data=self.private_user_data_for_room(
+                room_id, tags_by_room
+            ),
+        ))
+
+    def private_user_data_for_room(self, room_id, tags_by_room):
+        private_user_data = []
+        tags = tags_by_room.get(room_id)
+        if tags is not None:
+            private_user_data.append({
+                "type": "m.tag",
+                "content": {"tags": tags},
+            })
+        return private_user_data
+
+    @defer.inlineCallbacks
+    def ephemeral_by_room(self, sync_config, now_token, since_token=None):
+        """Get the ephemeral events for each room the user is in
+        Args:
+            sync_config (SyncConfig): The flags, filters and user for the sync.
+            now_token (StreamToken): Where the server is currently up to.
+            since_token (StreamToken): Where the server was when the client
+                last synced.
+        Returns:
+            A tuple of the now StreamToken, updated to reflect the which typing
+            events are included, and a dict mapping from room_id to a list of
+            typing events for that room.
+        """
+
+        typing_key = since_token.typing_key if since_token else "0"
+
+        rooms = yield self.store.get_rooms_for_user(sync_config.user.to_string())
+        room_ids = [room.room_id for room in rooms]
+
+        typing_source = self.event_sources.sources["typing"]
+        typing, typing_key = yield typing_source.get_new_events(
+            user=sync_config.user,
+            from_key=typing_key,
+            limit=sync_config.filter.ephemeral_limit(),
+            room_ids=room_ids,
+            is_guest=False,
         )
-        current_state_events = current_state.values()
+        now_token = now_token.copy_and_replace("typing_key", typing_key)
+
+        ephemeral_by_room = {}
 
-        defer.returnValue(RoomSyncResult(
+        for event in typing:
+            # we want to exclude the room_id from the event, but modifying the
+            # result returned by the event source is poor form (it might cache
+            # the object)
+            room_id = event["room_id"]
+            event_copy = {k: v for (k, v) in event.iteritems()
+                          if k != "room_id"}
+            ephemeral_by_room.setdefault(room_id, []).append(event_copy)
+
+        receipt_key = since_token.receipt_key if since_token else "0"
+
+        receipt_source = self.event_sources.sources["receipt"]
+        receipts, receipt_key = yield receipt_source.get_new_events(
+            user=sync_config.user,
+            from_key=receipt_key,
+            limit=sync_config.filter.ephemeral_limit(),
+            room_ids=room_ids,
+            # /sync doesn't support guest access, they can't get to this point in code
+            is_guest=False,
+        )
+        now_token = now_token.copy_and_replace("receipt_key", receipt_key)
+
+        for event in receipts:
+            room_id = event["room_id"]
+            # exclude room id, as above
+            event_copy = {k: v for (k, v) in event.iteritems()
+                          if k != "room_id"}
+            ephemeral_by_room.setdefault(room_id, []).append(event_copy)
+
+        defer.returnValue((now_token, ephemeral_by_room))
+
+    @defer.inlineCallbacks
+    def full_state_sync_for_archived_room(self, room_id, sync_config,
+                                          leave_event_id, leave_token,
+                                          timeline_since_token, tags_by_room):
+        """Sync a room for a client which is starting without any state
+        Returns:
+            A Deferred JoinedSyncResult.
+        """
+
+        batch = yield self.load_filtered_recents(
+            room_id, sync_config, leave_token, since_token=timeline_since_token
+        )
+
+        leave_state = yield self.store.get_state_for_event(leave_event_id)
+
+        defer.returnValue(ArchivedSyncResult(
             room_id=room_id,
-            published=room_id in published_room_ids,
-            events=recents,
-            prev_batch=prev_batch_token,
-            state=current_state_events,
-            limited=limited,
-            ephemeral=[],
+            timeline=batch,
+            state=leave_state,
+            private_user_data=self.private_user_data_for_room(
+                room_id, tags_by_room
+            ),
         ))
 
     @defer.inlineCallbacks
@@ -208,34 +369,25 @@ class SyncHandler(BaseHandler):
         Returns:
             A Deferred SyncResult.
         """
-        if sync_config.sort == "timeline,desc":
-            # TODO(mjark): Handle going through events in reverse order?.
-            # What does "most recent events" mean when applying the limits mean
-            # in this case?
-            raise NotImplementedError()
-
         now_token = yield self.event_sources.get_current_token()
 
+        rooms = yield self.store.get_rooms_for_user(sync_config.user.to_string())
+        room_ids = [room.room_id for room in rooms]
+
         presence_source = self.event_sources.sources["presence"]
-        presence, presence_key = yield presence_source.get_new_events_for_user(
+        presence, presence_key = yield presence_source.get_new_events(
             user=sync_config.user,
             from_key=since_token.presence_key,
-            limit=sync_config.limit,
+            limit=sync_config.filter.presence_limit(),
+            room_ids=room_ids,
+            # /sync doesn't support guest access, they can't get to this point in code
+            is_guest=False,
         )
         now_token = now_token.copy_and_replace("presence_key", presence_key)
 
-        typing_source = self.event_sources.sources["typing"]
-        typing, typing_key = yield typing_source.get_new_events_for_user(
-            user=sync_config.user,
-            from_key=since_token.typing_key,
-            limit=sync_config.limit,
+        now_token, ephemeral_by_room = yield self.ephemeral_by_room(
+            sync_config, now_token, since_token
         )
-        now_token = now_token.copy_and_replace("typing_key", typing_key)
-
-        typing_by_room = {event["room_id"]: [event] for event in typing}
-        for event in typing:
-            event.pop("room_id")
-        logger.debug("Typing %r", typing_by_room)
 
         rm_handler = self.hs.get_handlers().room_member_handler
         app_service = yield self.store.get_app_service_by_user_id(
@@ -243,35 +395,55 @@ class SyncHandler(BaseHandler):
         )
         if app_service:
             rooms = yield self.store.get_app_service_rooms(app_service)
-            room_ids = set(r.room_id for r in rooms)
+            joined_room_ids = set(r.room_id for r in rooms)
         else:
-            room_ids = yield rm_handler.get_joined_rooms_for_user(
+            joined_room_ids = yield rm_handler.get_joined_rooms_for_user(
                 sync_config.user
             )
 
-        # TODO (mjark): Does public mean "published"?
-        published_rooms = yield self.store.get_rooms(is_public=True)
-        published_room_ids = set(r["room_id"] for r in published_rooms)
+        timeline_limit = sync_config.filter.timeline_limit()
 
         room_events, _ = yield self.store.get_room_events_stream(
             sync_config.user.to_string(),
             from_key=since_token.room_key,
             to_key=now_token.room_key,
-            room_id=None,
-            limit=sync_config.limit + 1,
+            limit=timeline_limit + 1,
         )
 
-        rooms = []
-        if len(room_events) <= sync_config.limit:
+        tags_by_room = yield self.store.get_updated_tags(
+            sync_config.user.to_string(),
+            since_token.private_user_data_key,
+        )
+
+        joined = []
+        archived = []
+        if len(room_events) <= timeline_limit:
             # There is no gap in any of the rooms. Therefore we can just
             # partition the new events by room and return them.
+            logger.debug("Got %i events for incremental sync - not limited",
+                         len(room_events))
+
+            invite_events = []
+            leave_events = []
             events_by_room_id = {}
             for event in room_events:
                 events_by_room_id.setdefault(event.room_id, []).append(event)
-
-            for room_id in room_ids:
+                if event.room_id not in joined_room_ids:
+                    if (event.type == EventTypes.Member
+                            and event.state_key == sync_config.user.to_string()):
+                        if event.membership == Membership.INVITE:
+                            invite_events.append(event)
+                        elif event.membership in (Membership.LEAVE, Membership.BAN):
+                            leave_events.append(event)
+
+            for room_id in joined_room_ids:
                 recents = events_by_room_id.get(room_id, [])
-                state = [event for event in recents if event.is_state()]
+                logger.debug("Events for room %s: %r", room_id, recents)
+                state = {
+                    (event.type, event.state_key): event
+                    for event in recents if event.is_state()}
+                limited = False
+
                 if recents:
                     prev_batch = now_token.copy_and_replace(
                         "room_key", recents[0].internal_metadata.before
@@ -279,95 +451,87 @@ class SyncHandler(BaseHandler):
                 else:
                     prev_batch = now_token
 
-                state = yield self.check_joined_room(
-                    sync_config, room_id, state
-                )
+                just_joined = yield self.check_joined_room(sync_config, state)
+                if just_joined:
+                    logger.debug("User has just joined %s: needs full state",
+                                 room_id)
+                    state = yield self.get_state_at(room_id, now_token)
+                    # the timeline is inherently limited if we've just joined
+                    limited = True
 
-                room_sync = RoomSyncResult(
+                room_sync = JoinedSyncResult(
                     room_id=room_id,
-                    published=room_id in published_room_ids,
-                    events=recents,
-                    prev_batch=prev_batch,
+                    timeline=TimelineBatch(
+                        events=recents,
+                        prev_batch=prev_batch,
+                        limited=limited,
+                    ),
                     state=state,
-                    limited=False,
-                    ephemeral=typing_by_room.get(room_id, [])
+                    ephemeral=ephemeral_by_room.get(room_id, []),
+                    private_user_data=self.private_user_data_for_room(
+                        room_id, tags_by_room
+                    ),
                 )
+                logger.debug("Result for room %s: %r", room_id, room_sync)
+
                 if room_sync:
-                    rooms.append(room_sync)
+                    joined.append(room_sync)
+
         else:
-            for room_id in room_ids:
+            logger.debug("Got %i events for incremental sync - hit limit",
+                         len(room_events))
+
+            invite_events = yield self.store.get_invites_for_user(
+                sync_config.user.to_string()
+            )
+
+            leave_events = yield self.store.get_leave_and_ban_events_for_user(
+                sync_config.user.to_string()
+            )
+
+            for room_id in joined_room_ids:
                 room_sync = yield self.incremental_sync_with_gap_for_room(
                     room_id, sync_config, since_token, now_token,
-                    published_room_ids, typing_by_room
+                    ephemeral_by_room, tags_by_room
                 )
                 if room_sync:
-                    rooms.append(room_sync)
+                    joined.append(room_sync)
 
-        defer.returnValue(SyncResult(
-            public_user_data=presence,
-            private_user_data=[],
-            rooms=rooms,
-            next_batch=now_token,
-        ))
-
-    @defer.inlineCallbacks
-    def _filter_events_for_client(self, user_id, room_id, events):
-        event_id_to_state = yield self.store.get_state_for_events(
-            room_id, frozenset(e.event_id for e in events),
-            types=(
-                (EventTypes.RoomHistoryVisibility, ""),
-                (EventTypes.Member, user_id),
+        for leave_event in leave_events:
+            room_sync = yield self.incremental_sync_for_archived_room(
+                sync_config, leave_event, since_token, tags_by_room
             )
-        )
-
-        def allowed(event, state):
-            if event.type == EventTypes.RoomHistoryVisibility:
-                return True
-
-            membership_ev = state.get((EventTypes.Member, user_id), None)
-            if membership_ev:
-                membership = membership_ev.membership
-            else:
-                membership = Membership.LEAVE
-
-            if membership == Membership.JOIN:
-                return True
+            archived.append(room_sync)
 
-            history = state.get((EventTypes.RoomHistoryVisibility, ''), None)
-            if history:
-                visibility = history.content.get("history_visibility", "shared")
-            else:
-                visibility = "shared"
+        invited = [
+            InvitedSyncResult(room_id=event.room_id, invite=event)
+            for event in invite_events
+        ]
 
-            if visibility == "public":
-                return True
-            elif visibility == "shared":
-                return True
-            elif visibility == "joined":
-                return membership == Membership.JOIN
-            elif visibility == "invited":
-                return membership == Membership.INVITE
-
-            return True
-
-        defer.returnValue([
-            event
-            for event in events
-            if allowed(event, event_id_to_state[event.event_id])
-        ])
+        defer.returnValue(SyncResult(
+            presence=presence,
+            joined=joined,
+            invited=invited,
+            archived=archived,
+            next_batch=now_token,
+        ))
 
     @defer.inlineCallbacks
     def load_filtered_recents(self, room_id, sync_config, now_token,
                               since_token=None):
+        """
+        :returns a Deferred TimelineBatch
+        """
         limited = True
         recents = []
         filtering_factor = 2
-        load_limit = max(sync_config.limit * filtering_factor, 100)
+        timeline_limit = sync_config.filter.timeline_limit()
+        load_limit = max(timeline_limit * filtering_factor, 100)
         max_repeat = 3  # Only try a few times per room, otherwise
         room_key = now_token.room_key
         end_key = room_key
 
-        while limited and len(recents) < sync_config.limit and max_repeat:
+        while limited and len(recents) < timeline_limit and max_repeat:
             events, keys = yield self.store.get_recent_events_for_room(
                 room_id,
                 limit=load_limit + 1,
@@ -376,9 +540,9 @@ class SyncHandler(BaseHandler):
             )
             (room_key, _) = keys
             end_key = "s" + room_key.split('-')[-1]
-            loaded_recents = sync_config.filter.filter_room_events(events)
+            loaded_recents = sync_config.filter.filter_room_timeline(events)
             loaded_recents = yield self._filter_events_for_client(
-                sync_config.user.to_string(), room_id, loaded_recents,
+                sync_config.user.to_string(), loaded_recents,
             )
             loaded_recents.extend(recents)
             recents = loaded_recents
@@ -386,64 +550,64 @@ class SyncHandler(BaseHandler):
                 limited = False
             max_repeat -= 1
 
-        if len(recents) > sync_config.limit:
-            recents = recents[-sync_config.limit:]
+        if len(recents) > timeline_limit:
+            limited = True
+            recents = recents[-timeline_limit:]
             room_key = recents[0].internal_metadata.before
 
         prev_batch_token = now_token.copy_and_replace(
             "room_key", room_key
         )
 
-        defer.returnValue((recents, prev_batch_token, limited))
+        defer.returnValue(TimelineBatch(
+            events=recents, prev_batch=prev_batch_token, limited=limited
+        ))
 
     @defer.inlineCallbacks
     def incremental_sync_with_gap_for_room(self, room_id, sync_config,
                                            since_token, now_token,
-                                           published_room_ids, typing_by_room):
+                                           ephemeral_by_room, tags_by_room):
         """ Get the incremental delta needed to bring the client up to date for
         the room. Gives the client the most recent events and the changes to
         state.
         Returns:
-            A Deferred RoomSyncResult
+            A Deferred JoinedSyncResult
         """
+        logger.debug("Doing incremental sync for room %s between %s and %s",
+                     room_id, since_token, now_token)
 
         # TODO(mjark): Check for redactions we might have missed.
 
-        recents, prev_batch_token, limited = yield self.load_filtered_recents(
+        batch = yield self.load_filtered_recents(
             room_id, sync_config, now_token, since_token,
         )
 
-        logging.debug("Recents %r", recents)
+        logging.debug("Recents %r", batch)
 
-        # TODO(mjark): This seems racy since this isn't being passed a
-        # token to indicate what point in the stream this is
-        current_state = yield self.state_handler.get_current_state(
-            room_id
-        )
-        current_state_events = current_state.values()
+        current_state = yield self.get_state_at(room_id, now_token)
 
-        state_at_previous_sync = yield self.get_state_at_previous_sync(
-            room_id, since_token=since_token
+        state_at_previous_sync = yield self.get_state_at(
+            room_id, stream_position=since_token
         )
 
-        state_events_delta = yield self.compute_state_delta(
+        state = yield self.compute_state_delta(
             since_token=since_token,
             previous_state=state_at_previous_sync,
-            current_state=current_state_events,
+            current_state=current_state,
         )
 
-        state_events_delta = yield self.check_joined_room(
-            sync_config, room_id, state_events_delta
-        )
+        just_joined = yield self.check_joined_room(sync_config, state)
+        if just_joined:
+            state = yield self.get_state_at(room_id, now_token)
 
-        room_sync = RoomSyncResult(
+        room_sync = JoinedSyncResult(
             room_id=room_id,
-            published=room_id in published_room_ids,
-            events=recents,
-            prev_batch=prev_batch_token,
-            state=state_events_delta,
-            limited=limited,
-            ephemeral=typing_by_room.get(room_id, [])
+            timeline=batch,
+            state=state,
+            ephemeral=ephemeral_by_room.get(room_id, []),
+            private_user_data=self.private_user_data_for_room(
+                room_id, tags_by_room
+            ),
         )
 
         logging.debug("Room sync: %r", room_sync)
@@ -451,58 +615,125 @@ class SyncHandler(BaseHandler):
         defer.returnValue(room_sync)
 
     @defer.inlineCallbacks
-    def get_state_at_previous_sync(self, room_id, since_token):
-        """ Get the room state at the previous sync the client made.
+    def incremental_sync_for_archived_room(self, sync_config, leave_event,
+                                           since_token, tags_by_room):
+        """ Get the incremental delta needed to bring the client up to date for
+        the archived room.
         Returns:
-            A Deferred list of Events.
+            A Deferred ArchivedSyncResult
+        """
+
+        stream_token = yield self.store.get_stream_token_for_event(
+            leave_event.event_id
+        )
+
+        leave_token = since_token.copy_and_replace("room_key", stream_token)
+
+        batch = yield self.load_filtered_recents(
+            leave_event.room_id, sync_config, leave_token, since_token,
+        )
+
+        logging.debug("Recents %r", batch)
+
+        state_events_at_leave = yield self.store.get_state_for_event(
+            leave_event.event_id
+        )
+
+        state_at_previous_sync = yield self.get_state_at(
+            leave_event.room_id, stream_position=since_token
+        )
+
+        state_events_delta = yield self.compute_state_delta(
+            since_token=since_token,
+            previous_state=state_at_previous_sync,
+            current_state=state_events_at_leave,
+        )
+
+        room_sync = ArchivedSyncResult(
+            room_id=leave_event.room_id,
+            timeline=batch,
+            state=state_events_delta,
+            private_user_data=self.private_user_data_for_room(
+                leave_event.room_id, tags_by_room
+            ),
+        )
+
+        logging.debug("Room sync: %r", room_sync)
+
+        defer.returnValue(room_sync)
+
+    @defer.inlineCallbacks
+    def get_state_after_event(self, event):
+        """
+        Get the room state after the given event
+
+        :param synapse.events.EventBase event: event of interest
+        :return: A Deferred map from ((type, state_key)->Event)
+        """
+        state = yield self.store.get_state_for_event(event.event_id)
+        if event.is_state():
+            state = state.copy()
+            state[(event.type, event.state_key)] = event
+        defer.returnValue(state)
+
+    @defer.inlineCallbacks
+    def get_state_at(self, room_id, stream_position):
+        """ Get the room state at a particular stream position
+        :param str room_id: room for which to get state
+        :param StreamToken stream_position: point at which to get state
+        :returns: A Deferred map from ((type, state_key)->Event)
         """
         last_events, token = yield self.store.get_recent_events_for_room(
-            room_id, end_token=since_token.room_key, limit=1,
+            room_id, end_token=stream_position.room_key, limit=1,
         )
 
         if last_events:
-            last_event = last_events[0]
-            last_context = yield self.state_handler.compute_event_context(
-                last_event
-            )
-            if last_event.is_state():
-                state = [last_event] + last_context.current_state.values()
-            else:
-                state = last_context.current_state.values()
+            last_event = last_events[-1]
+            state = yield self.get_state_after_event(last_event)
+
         else:
-            state = ()
+            # no events in this room - so presumably no state
+            state = {}
         defer.returnValue(state)
 
     def compute_state_delta(self, since_token, previous_state, current_state):
         """ Works out the differnce in state between the current state and the
         state the client got when it last performed a sync.
-        Returns:
-            A list of events.
+
+        :param str since_token: the point we are comparing against
+        :param dict[(str,str), synapse.events.FrozenEvent] previous_state: the
+            state to compare to
+        :param dict[(str,str), synapse.events.FrozenEvent] current_state: the
+            new state
+
+        :returns A new event dictionary
         """
         # TODO(mjark) Check if the state events were received by the server
         # after the previous sync, since we need to include those state
         # updates even if they occured logically before the previous event.
         # TODO(mjark) Check for new redactions in the state events.
-        previous_dict = {event.event_id: event for event in previous_state}
-        state_delta = []
-        for event in current_state:
-            if event.event_id not in previous_dict:
-                state_delta.append(event)
+
+        state_delta = {}
+        for key, event in current_state.iteritems():
+            if (key not in previous_state or
+                    previous_state[key].event_id != event.event_id):
+                state_delta[key] = event
         return state_delta
 
-    @defer.inlineCallbacks
-    def check_joined_room(self, sync_config, room_id, state_delta):
-        joined = False
-        for event in state_delta:
-            if (
-                event.type == EventTypes.Member
-                and event.state_key == sync_config.user.to_string()
-            ):
-                if event.content["membership"] == Membership.JOIN:
-                    joined = True
-
-        if joined:
-            res = yield self.state_handler.get_current_state(room_id)
-            state_delta = res.values()
-
-        defer.returnValue(state_delta)
+    def check_joined_room(self, sync_config, state_delta):
+        """
+        Check if the user has just joined the given room (so should
+        be given the full state)
+
+        :param sync_config:
+        :param dict[(str,str), synapse.events.FrozenEvent] state_delta: the
+           difference in state since the last sync
+
+        :returns A deferred Tuple (state_delta, limited)
+        """
+        join_event = state_delta.get((
+            EventTypes.Member, sync_config.user.to_string()), None)
+        if join_event is not None:
+            if join_event.content["membership"] == Membership.JOIN:
+                return True
+        return False