Merge branch 'master' of git+ssh://github.com/matrix-org/synapse

1 files changed, 513 insertions, 406 deletions

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index feea407ea2..1d0f0058a2 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-# Copyright 2015 OpenMarket Ltd
+# Copyright 2015 - 2016 OpenMarket Ltd
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,22 +15,25 @@
 
 from ._base import BaseHandler
 
+from synapse.streams.config import PaginationConfig
 from synapse.api.constants import Membership, EventTypes
-from synapse.api.errors import GuestAccessError
 from synapse.util import unwrapFirstError
+from synapse.util.logcontext import LoggingContext, preserve_fn
+from synapse.util.metrics import Measure
 
 from twisted.internet import defer
 
 import collections
 import logging
+import itertools
 
 logger = logging.getLogger(__name__)
 
 
 SyncConfig = collections.namedtuple("SyncConfig", [
     "user",
+    "filter_collection",
     "is_guest",
-    "filter",
 ])
 
 
@@ -54,6 +57,7 @@ class JoinedSyncResult(collections.namedtuple("JoinedSyncResult", [
     "state",             # dict[(str, str), FrozenEvent]
     "ephemeral",
     "account_data",
+    "unread_notifications",
 ])):
     __slots__ = []
 
@@ -66,10 +70,12 @@ class JoinedSyncResult(collections.namedtuple("JoinedSyncResult", [
             or self.state
             or self.ephemeral
             or self.account_data
+            # nb the notification count does not, er, count: if there's nothing
+            # else in the result, we don't need to send it.
         )
 
 
-class ArchivedSyncResult(collections.namedtuple("JoinedSyncResult", [
+class ArchivedSyncResult(collections.namedtuple("ArchivedSyncResult", [
     "room_id",            # str
     "timeline",           # TimelineBatch
     "state",              # dict[(str, str), FrozenEvent]
@@ -115,11 +121,9 @@ class SyncResult(collections.namedtuple("SyncResult", [
         events.
         """
         return bool(
-            self.presence or self.joined or self.invited
+            self.presence or self.joined or self.invited or self.archived
         )
 
-GuestRoom = collections.namedtuple("GuestRoom", ("room_id", "membership"))
-
 
 class SyncHandler(BaseHandler):
 
@@ -138,45 +142,32 @@ class SyncHandler(BaseHandler):
             A Deferred SyncResult.
         """
 
-        if sync_config.is_guest:
-            bad_rooms = []
-            for room_id in sync_config.filter.list_rooms():
-                world_readable = yield self._is_world_readable(room_id)
-                if not world_readable:
-                    bad_rooms.append(room_id)
-
-            if bad_rooms:
-                raise GuestAccessError(
-                    bad_rooms, 403, "Guest access not allowed"
-                )
+        context = LoggingContext.current_context()
+        if context:
+            if since_token is None:
+                context.tag = "initial_sync"
+            elif full_state:
+                context.tag = "full_state_sync"
+            else:
+                context.tag = "incremental_sync"
 
         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)
+            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)
 
             result = yield self.notifier.wait_for_events(
-                sync_config.user, timeout, current_sync_callback,
-                from_token=since_token
+                sync_config.user.to_string(), timeout, current_sync_callback,
+                from_token=since_token,
             )
             defer.returnValue(result)
 
-    @defer.inlineCallbacks
-    def _is_world_readable(self, room_id):
-        state = yield self.hs.get_state_handler().get_current_state(
-            room_id,
-            EventTypes.RoomHistoryVisibility
-        )
-        if state and "history_visibility" in state.content:
-            defer.returnValue(state.content["history_visibility"] == "world_readable")
-        else:
-            defer.returnValue(False)
-
     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.
@@ -200,100 +191,100 @@ class SyncHandler(BaseHandler):
         """
         now_token = yield self.event_sources.get_current_token()
 
-        if sync_config.is_guest:
-            room_list = [
-                GuestRoom(room_id, Membership.JOIN)
-                for room_id in sync_config.filter.list_rooms()
-            ]
-
-            account_data = {}
-            account_data_by_room = {}
-            tags_by_room = {}
+        now_token, ephemeral_by_room = yield self.ephemeral_by_room(
+            sync_config, now_token
+        )
 
-        else:
-            membership_list = (Membership.INVITE, Membership.JOIN)
-            if sync_config.filter.include_leave:
-                membership_list += (Membership.LEAVE, Membership.BAN)
+        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?
+        pagination_config = PaginationConfig(from_token=now_token)
+        presence, _ = yield presence_stream.get_pagination_rows(
+            user=sync_config.user,
+            pagination_config=pagination_config.get_source_config("presence"),
+            key=None
+        )
 
-            room_list = yield self.store.get_rooms_for_user_where_membership_is(
-                user_id=sync_config.user.to_string(),
-                membership_list=membership_list
-            )
+        membership_list = (Membership.INVITE, Membership.JOIN)
+        if sync_config.filter_collection.include_leave:
+            membership_list += (Membership.LEAVE, Membership.BAN)
 
-            account_data, account_data_by_room = (
-                yield self.store.get_account_data_for_user(
-                    sync_config.user.to_string()
-                )
-            )
+        room_list = yield self.store.get_rooms_for_user_where_membership_is(
+            user_id=sync_config.user.to_string(),
+            membership_list=membership_list
+        )
 
-            tags_by_room = yield self.store.get_tags_for_user(
+        account_data, account_data_by_room = (
+            yield self.store.get_account_data_for_user(
                 sync_config.user.to_string()
             )
-
-        presence_stream = self.event_sources.sources["presence"]
-
-        joined_room_ids = [
-            room.room_id for room in room_list
-            if room.membership == Membership.JOIN
-        ]
-
-        presence, _ = yield presence_stream.get_new_events(
-            from_key=0,
-            user=sync_config.user,
-            room_ids=joined_room_ids,
-            is_guest=sync_config.is_guest,
         )
 
-        now_token, ephemeral_by_room = yield self.ephemeral_by_room(
-            sync_config, now_token, joined_room_ids
+        tags_by_room = yield self.store.get_tags_for_user(
+            sync_config.user.to_string()
         )
 
         joined = []
         invited = []
         archived = []
         deferreds = []
-        for event in room_list:
-            if event.membership == Membership.JOIN:
-                room_sync_deferred = 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,
-                    account_data_by_room=account_data_by_room,
-                )
-                room_sync_deferred.addCallback(joined.append)
-                deferreds.append(room_sync_deferred)
-            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_deferred = 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,
-                    account_data_by_room=account_data_by_room,
-                )
-                room_sync_deferred.addCallback(archived.append)
-                deferreds.append(room_sync_deferred)
 
-        yield defer.gatherResults(
-            deferreds, consumeErrors=True
-        ).addErrback(unwrapFirstError)
+        room_list_chunks = [room_list[i:i + 10] for i in xrange(0, len(room_list), 10)]
+        for room_list_chunk in room_list_chunks:
+            for event in room_list_chunk:
+                if event.membership == Membership.JOIN:
+                    room_sync_deferred = preserve_fn(
+                        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,
+                        account_data_by_room=account_data_by_room,
+                    )
+                    room_sync_deferred.addCallback(joined.append)
+                    deferreds.append(room_sync_deferred)
+                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_deferred = preserve_fn(
+                        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,
+                        account_data_by_room=account_data_by_room,
+                    )
+                    room_sync_deferred.addCallback(archived.append)
+                    deferreds.append(room_sync_deferred)
+
+            yield defer.gatherResults(
+                deferreds, consumeErrors=True
+            ).addErrback(unwrapFirstError)
+
+        account_data_for_user = sync_config.filter_collection.filter_account_data(
+            self.account_data_for_user(account_data)
+        )
+
+        presence = sync_config.filter_collection.filter_presence(
+            presence
+        )
 
         defer.returnValue(SyncResult(
             presence=presence,
-            account_data=self.account_data_for_user(account_data),
+            account_data=account_data_for_user,
             joined=joined,
             invited=invited,
             archived=archived,
@@ -314,17 +305,18 @@ class SyncHandler(BaseHandler):
             room_id, sync_config, now_token, since_token=timeline_since_token
         )
 
-        current_state = yield self.get_state_at(room_id, now_token)
+        room_sync = yield self.incremental_sync_with_gap_for_room(
+            room_id, sync_config,
+            now_token=now_token,
+            since_token=timeline_since_token,
+            ephemeral_by_room=ephemeral_by_room,
+            tags_by_room=tags_by_room,
+            account_data_by_room=account_data_by_room,
+            batch=batch,
+            full_state=True,
+        )
 
-        defer.returnValue(JoinedSyncResult(
-            room_id=room_id,
-            timeline=batch,
-            state=current_state,
-            ephemeral=ephemeral_by_room.get(room_id, []),
-            account_data=self.account_data_for_room(
-                room_id, tags_by_room, account_data_by_room
-            ),
-        ))
+        defer.returnValue(room_sync)
 
     def account_data_for_user(self, account_data):
         account_data_events = []
@@ -356,13 +348,11 @@ class SyncHandler(BaseHandler):
         return account_data_events
 
     @defer.inlineCallbacks
-    def ephemeral_by_room(self, sync_config, now_token, room_ids,
-                          since_token=None):
+    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.
-            room_ids (list): List of room id strings to get data for.
             since_token (StreamToken): Where the server was when the client
                 last synced.
         Returns:
@@ -371,76 +361,68 @@ class SyncHandler(BaseHandler):
             typing events for that room.
         """
 
-        typing_key = since_token.typing_key if since_token else "0"
-
-        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,
-        )
-        now_token = now_token.copy_and_replace("typing_key", typing_key)
-
-        ephemeral_by_room = {}
+        with Measure(self.clock, "ephemeral_by_room"):
+            typing_key = since_token.typing_key if since_token else "0"
 
-        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"
+            rooms = yield self.store.get_rooms_for_user(sync_config.user.to_string())
+            room_ids = [room.room_id for room in rooms]
 
-        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)
+            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_collection.ephemeral_limit(),
+                room_ids=room_ids,
+                is_guest=sync_config.is_guest,
+            )
+            now_token = now_token.copy_and_replace("typing_key", typing_key)
+
+            ephemeral_by_room = {}
+
+            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_collection.ephemeral_limit(),
+                room_ids=room_ids,
+                is_guest=sync_config.is_guest,
+            )
+            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)
+            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,
                                           account_data_by_room):
         """Sync a room for a client which is starting without any state
         Returns:
-            A Deferred JoinedSyncResult.
+            A Deferred ArchivedSyncResult.
         """
 
-        batch = yield self.load_filtered_recents(
-            room_id, sync_config, leave_token, since_token=timeline_since_token
+        return self.incremental_sync_for_archived_room(
+            sync_config, room_id, leave_event_id, timeline_since_token, tags_by_room,
+            account_data_by_room, full_state=True, leave_token=leave_token,
         )
 
-        leave_state = yield self.store.get_state_for_event(leave_event_id)
-
-        defer.returnValue(ArchivedSyncResult(
-            room_id=room_id,
-            timeline=batch,
-            state=leave_state,
-            account_data=self.account_data_for_room(
-                room_id, tags_by_room, account_data_by_room
-            ),
-        ))
-
     @defer.inlineCallbacks
     def incremental_sync_with_gap(self, sync_config, since_token):
         """ Get the incremental delta needed to bring the client up to
@@ -450,49 +432,23 @@ class SyncHandler(BaseHandler):
         """
         now_token = yield self.event_sources.get_current_token()
 
-        if sync_config.is_guest:
-            room_ids = sync_config.filter.list_rooms()
-
-            tags_by_room = {}
-            account_data = {}
-            account_data_by_room = {}
-
-        else:
-            rooms = yield self.store.get_rooms_for_user(
-                sync_config.user.to_string()
-            )
-            room_ids = [room.room_id for room in rooms]
-
-            now_token, ephemeral_by_room = yield self.ephemeral_by_room(
-                sync_config, now_token, since_token
-            )
-
-            tags_by_room = yield self.store.get_updated_tags(
-                sync_config.user.to_string(),
-                since_token.account_data_key,
-            )
-
-            account_data, account_data_by_room = (
-                yield self.store.get_updated_account_data_for_user(
-                    sync_config.user.to_string(),
-                    since_token.account_data_key,
-                )
-            )
-
-        now_token, ephemeral_by_room = yield self.ephemeral_by_room(
-            sync_config, now_token, room_ids, since_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(
             user=sync_config.user,
             from_key=since_token.presence_key,
-            limit=sync_config.filter.presence_limit(),
+            limit=sync_config.filter_collection.presence_limit(),
             room_ids=room_ids,
             is_guest=sync_config.is_guest,
         )
         now_token = now_token.copy_and_replace("presence_key", presence_key)
 
+        now_token, ephemeral_by_room = yield self.ephemeral_by_room(
+            sync_config, now_token, 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()
@@ -505,114 +461,138 @@ class SyncHandler(BaseHandler):
                 sync_config.user
             )
 
-        timeline_limit = sync_config.filter.timeline_limit()
+        user_id = sync_config.user.to_string()
 
-        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,
-            limit=timeline_limit + 1,
-            room_ids=room_ids if sync_config.is_guest else (),
-            is_guest=sync_config.is_guest,
+        timeline_limit = sync_config.filter_collection.timeline_limit()
+
+        tags_by_room = yield self.store.get_updated_tags(
+            user_id,
+            since_token.account_data_key,
         )
 
-        joined = []
+        account_data, account_data_by_room = (
+            yield self.store.get_updated_account_data_for_user(
+                user_id,
+                since_token.account_data_key,
+            )
+        )
+
+        # Get a list of membership change events that have happened.
+        rooms_changed = yield self.store.get_membership_changes_for_user(
+            user_id, since_token.room_key, now_token.room_key
+        )
+
+        mem_change_events_by_room_id = {}
+        for event in rooms_changed:
+            mem_change_events_by_room_id.setdefault(event.room_id, []).append(event)
+
+        newly_joined_rooms = []
         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)
-                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, [])
-                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
+        invited = []
+        for room_id, events in mem_change_events_by_room_id.items():
+            non_joins = [e for e in events if e.membership != Membership.JOIN]
+            has_join = len(non_joins) != len(events)
+
+            # We want to figure out if we joined the room at some point since
+            # the last sync (even if we have since left). This is to make sure
+            # we do send down the room, and with full state, where necessary
+            if room_id in joined_room_ids or has_join:
+                old_state = yield self.get_state_at(room_id, since_token)
+                old_mem_ev = old_state.get((EventTypes.Member, user_id), None)
+                if not old_mem_ev or old_mem_ev.membership != Membership.JOIN:
+                        newly_joined_rooms.append(room_id)
+
+                if room_id in joined_room_ids:
+                    continue
+
+            if not non_joins:
+                continue
+
+            # Only bother if we're still currently invited
+            should_invite = non_joins[-1].membership == Membership.INVITE
+            if should_invite:
+                room_sync = InvitedSyncResult(room_id, invite=non_joins[-1])
+                if room_sync:
+                    invited.append(room_sync)
 
-                if recents:
-                    prev_batch = now_token.copy_and_replace(
-                        "room_key", recents[0].internal_metadata.before
-                    )
-                else:
-                    prev_batch = now_token
-
-                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 = JoinedSyncResult(
-                    room_id=room_id,
-                    timeline=TimelineBatch(
-                        events=recents,
-                        prev_batch=prev_batch,
-                        limited=limited,
-                    ),
-                    state=state,
-                    ephemeral=ephemeral_by_room.get(room_id, []),
-                    account_data=self.account_data_for_room(
-                        room_id, tags_by_room, account_data_by_room
-                    ),
-                )
-                logger.debug("Result for room %s: %r", room_id, room_sync)
+            # Always include leave/ban events. Just take the last one.
+            # TODO: How do we handle ban -> leave in same batch?
+            leave_events = [
+                e for e in non_joins
+                if e.membership in (Membership.LEAVE, Membership.BAN)
+            ]
 
+            if leave_events:
+                leave_event = leave_events[-1]
+                room_sync = yield self.incremental_sync_for_archived_room(
+                    sync_config, room_id, leave_event.event_id, since_token,
+                    tags_by_room, account_data_by_room,
+                    full_state=room_id in newly_joined_rooms
+                )
                 if room_sync:
-                    joined.append(room_sync)
+                    archived.append(room_sync)
 
-        else:
-            logger.debug("Got %i events for incremental sync - hit limit",
-                         len(room_events))
+        # Get all events for rooms we're currently joined to.
+        room_to_events = yield self.store.get_room_events_stream_for_rooms(
+            room_ids=joined_room_ids,
+            from_key=since_token.room_key,
+            to_key=now_token.room_key,
+            limit=timeline_limit + 1,
+        )
 
-            invite_events = yield self.store.get_invites_for_user(
-                sync_config.user.to_string()
-            )
+        joined = []
+        # We loop through all room ids, even if there are no new events, in case
+        # there are non room events taht we need to notify about.
+        for room_id in joined_room_ids:
+            room_entry = room_to_events.get(room_id, None)
 
-            leave_events = yield self.store.get_leave_and_ban_events_for_user(
-                sync_config.user.to_string()
-            )
+            if room_entry:
+                events, start_key = room_entry
 
-            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,
-                    ephemeral_by_room, tags_by_room, account_data_by_room
-                )
-                if room_sync:
-                    joined.append(room_sync)
+                prev_batch_token = now_token.copy_and_replace("room_key", start_key)
+
+                newly_joined_room = room_id in newly_joined_rooms
+                full_state = newly_joined_room
 
-        for leave_event in leave_events:
-            room_sync = yield self.incremental_sync_for_archived_room(
-                sync_config, leave_event, since_token, tags_by_room,
-                account_data_by_room
+                batch = yield self.load_filtered_recents(
+                    room_id, sync_config, prev_batch_token,
+                    since_token=since_token,
+                    recents=events,
+                    newly_joined_room=newly_joined_room,
+                )
+            else:
+                batch = TimelineBatch(
+                    events=[],
+                    prev_batch=since_token,
+                    limited=False,
+                )
+                full_state = False
+
+            room_sync = yield self.incremental_sync_with_gap_for_room(
+                room_id=room_id,
+                sync_config=sync_config,
+                since_token=since_token,
+                now_token=now_token,
+                ephemeral_by_room=ephemeral_by_room,
+                tags_by_room=tags_by_room,
+                account_data_by_room=account_data_by_room,
+                batch=batch,
+                full_state=full_state,
             )
-            archived.append(room_sync)
+            if room_sync:
+                joined.append(room_sync)
+
+        account_data_for_user = sync_config.filter_collection.filter_account_data(
+            self.account_data_for_user(account_data)
+        )
 
-        invited = [
-            InvitedSyncResult(room_id=event.room_id, invite=event)
-            for event in invite_events
-        ]
+        presence = sync_config.filter_collection.filter_presence(
+            presence
+        )
 
         defer.returnValue(SyncResult(
             presence=presence,
-            account_data=self.account_data_for_user(account_data),
+            account_data=account_data_for_user,
             joined=joined,
             invited=invited,
             archived=archived,
@@ -621,152 +601,169 @@ class SyncHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def load_filtered_recents(self, room_id, sync_config, now_token,
-                              since_token=None):
+                              since_token=None, recents=None, newly_joined_room=False):
         """
         :returns a Deferred TimelineBatch
         """
-        limited = True
-        recents = []
-        filtering_factor = 2
-        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) < timeline_limit and max_repeat:
-            events, keys = yield self.store.get_recent_events_for_room(
-                room_id,
-                limit=load_limit + 1,
-                from_token=since_token.room_key if since_token else None,
-                end_token=end_key,
-            )
-            (room_key, _) = keys
-            end_key = "s" + room_key.split('-')[-1]
-            loaded_recents = sync_config.filter.filter_room_timeline(events)
-            loaded_recents = yield self._filter_events_for_client(
-                sync_config.user.to_string(),
-                loaded_recents,
-                is_guest=sync_config.is_guest,
-                require_all_visible_for_guests=False
-            )
-            loaded_recents.extend(recents)
-            recents = loaded_recents
-            if len(events) <= load_limit:
+        with Measure(self.clock, "load_filtered_recents"):
+            filtering_factor = 2
+            timeline_limit = sync_config.filter_collection.timeline_limit()
+            load_limit = max(timeline_limit * filtering_factor, 10)
+            max_repeat = 5  # Only try a few times per room, otherwise
+            room_key = now_token.room_key
+            end_key = room_key
+
+            if recents is None or newly_joined_room or timeline_limit < len(recents):
+                limited = True
+            else:
                 limited = False
-            max_repeat -= 1
 
-        if len(recents) > timeline_limit:
-            limited = True
-            recents = recents[-timeline_limit:]
-            room_key = recents[0].internal_metadata.before
+            if recents is not None:
+                recents = sync_config.filter_collection.filter_room_timeline(recents)
+                recents = yield self._filter_events_for_client(
+                    sync_config.user.to_string(),
+                    recents,
+                    is_peeking=sync_config.is_guest,
+                )
+            else:
+                recents = []
+
+            since_key = None
+            if since_token and not newly_joined_room:
+                since_key = since_token.room_key
+
+            while limited and len(recents) < timeline_limit and max_repeat:
+                events, end_key = yield self.store.get_room_events_stream_for_room(
+                    room_id,
+                    limit=load_limit + 1,
+                    from_key=since_key,
+                    to_key=end_key,
+                )
+                loaded_recents = sync_config.filter_collection.filter_room_timeline(
+                    events
+                )
+                loaded_recents = yield self._filter_events_for_client(
+                    sync_config.user.to_string(),
+                    loaded_recents,
+                    is_peeking=sync_config.is_guest,
+                )
+                loaded_recents.extend(recents)
+                recents = loaded_recents
+
+                if len(events) <= load_limit:
+                    limited = False
+                    break
+                max_repeat -= 1
 
-        prev_batch_token = now_token.copy_and_replace(
-            "room_key", room_key
-        )
+            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(TimelineBatch(
-            events=recents, prev_batch=prev_batch_token, limited=limited
+            events=recents,
+            prev_batch=prev_batch_token,
+            limited=limited or newly_joined_room
         ))
 
     @defer.inlineCallbacks
     def incremental_sync_with_gap_for_room(self, room_id, sync_config,
                                            since_token, now_token,
                                            ephemeral_by_room, tags_by_room,
-                                           account_data_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 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.
-
-        batch = yield self.load_filtered_recents(
-            room_id, sync_config, now_token, since_token,
+                                           account_data_by_room,
+                                           batch, full_state=False):
+        state = yield self.compute_state_delta(
+            room_id, batch, sync_config, since_token, now_token,
+            full_state=full_state
         )
 
-        logging.debug("Recents %r", batch)
-
-        current_state = yield self.get_state_at(room_id, now_token)
-
-        state_at_previous_sync = yield self.get_state_at(
-            room_id, stream_position=since_token
+        account_data = self.account_data_for_room(
+            room_id, tags_by_room, account_data_by_room
         )
 
-        state = yield self.compute_state_delta(
-            since_token=since_token,
-            previous_state=state_at_previous_sync,
-            current_state=current_state,
+        account_data = sync_config.filter_collection.filter_room_account_data(
+            account_data
         )
 
-        just_joined = yield self.check_joined_room(sync_config, state)
-        if just_joined:
-            state = yield self.get_state_at(room_id, now_token)
+        ephemeral = sync_config.filter_collection.filter_room_ephemeral(
+            ephemeral_by_room.get(room_id, [])
+        )
 
+        unread_notifications = {}
         room_sync = JoinedSyncResult(
             room_id=room_id,
             timeline=batch,
             state=state,
-            ephemeral=ephemeral_by_room.get(room_id, []),
-            account_data=self.account_data_for_room(
-                room_id, tags_by_room, account_data_by_room
-            ),
+            ephemeral=ephemeral,
+            account_data=account_data,
+            unread_notifications=unread_notifications,
         )
 
-        logging.debug("Room sync: %r", room_sync)
+        if room_sync:
+            notifs = yield self.unread_notifs_for_room_id(
+                room_id, sync_config
+            )
+
+            if notifs is not None:
+                unread_notifications["notification_count"] = notifs["notify_count"]
+                unread_notifications["highlight_count"] = notifs["highlight_count"]
+
+        logger.debug("Room sync: %r", room_sync)
 
         defer.returnValue(room_sync)
 
     @defer.inlineCallbacks
-    def incremental_sync_for_archived_room(self, sync_config, leave_event,
+    def incremental_sync_for_archived_room(self, sync_config, room_id, leave_event_id,
                                            since_token, tags_by_room,
-                                           account_data_by_room):
+                                           account_data_by_room, full_state,
+                                           leave_token=None):
         """ Get the incremental delta needed to bring the client up to date for
         the archived room.
         Returns:
             A Deferred ArchivedSyncResult
         """
 
-        stream_token = yield self.store.get_stream_token_for_event(
-            leave_event.event_id
-        )
+        if not leave_token:
+            stream_token = yield self.store.get_stream_token_for_event(
+                leave_event_id
+            )
 
-        leave_token = since_token.copy_and_replace("room_key", stream_token)
+            leave_token = since_token.copy_and_replace("room_key", stream_token)
+
+        if since_token and since_token.is_after(leave_token):
+            defer.returnValue(None)
 
         batch = yield self.load_filtered_recents(
-            leave_event.room_id, sync_config, leave_token, since_token,
+            room_id, sync_config, leave_token, since_token,
         )
 
-        logging.debug("Recents %r", batch)
+        logger.debug("Recents %r", batch)
 
-        state_events_at_leave = yield self.store.get_state_for_event(
-            leave_event.event_id
+        state_events_delta = yield self.compute_state_delta(
+            room_id, batch, sync_config, since_token, leave_token,
+            full_state=full_state
         )
 
-        state_at_previous_sync = yield self.get_state_at(
-            leave_event.room_id, stream_position=since_token
+        account_data = self.account_data_for_room(
+            room_id, tags_by_room, account_data_by_room
         )
 
-        state_events_delta = yield self.compute_state_delta(
-            since_token=since_token,
-            previous_state=state_at_previous_sync,
-            current_state=state_events_at_leave,
+        account_data = sync_config.filter_collection.filter_room_account_data(
+            account_data
         )
 
         room_sync = ArchivedSyncResult(
-            room_id=leave_event.room_id,
+            room_id=room_id,
             timeline=batch,
             state=state_events_delta,
-            account_data=self.account_data_for_room(
-                leave_event.room_id, tags_by_room, account_data_by_room
-            ),
+            account_data=account_data,
         )
 
-        logging.debug("Room sync: %r", room_sync)
+        logger.debug("Room sync: %r", room_sync)
 
         defer.returnValue(room_sync)
 
@@ -804,15 +801,19 @@ class SyncHandler(BaseHandler):
             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.
-
-        :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
+    @defer.inlineCallbacks
+    def compute_state_delta(self, room_id, batch, sync_config, since_token, now_token,
+                            full_state):
+        """ Works out the differnce in state between the start of the timeline
+        and the previous sync.
+
+        :param str room_id
+        :param TimelineBatch batch: The timeline batch for the room that will
+            be sent to the user.
+        :param sync_config
+        :param str since_token: Token of the end of the previous batch. May be None.
+        :param str now_token: Token of the end of the current batch.
+        :param bool full_state: Whether to force returning the full state.
 
         :returns A new event dictionary
         """
@@ -821,12 +822,53 @@ class SyncHandler(BaseHandler):
         # updates even if they occured logically before the previous event.
         # TODO(mjark) Check for new redactions in the state events.
 
-        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
+        with Measure(self.clock, "compute_state_delta"):
+            if full_state:
+                if batch:
+                    state = yield self.store.get_state_for_event(
+                        batch.events[0].event_id
+                    )
+                else:
+                    state = yield self.get_state_at(
+                        room_id, stream_position=now_token
+                    )
+
+                timeline_state = {
+                    (event.type, event.state_key): event
+                    for event in batch.events if event.is_state()
+                }
+
+                state = _calculate_state(
+                    timeline_contains=timeline_state,
+                    timeline_start=state,
+                    previous={},
+                )
+            elif batch.limited:
+                state_at_previous_sync = yield self.get_state_at(
+                    room_id, stream_position=since_token
+                )
+
+                state_at_timeline_start = yield self.store.get_state_for_event(
+                    batch.events[0].event_id
+                )
+
+                timeline_state = {
+                    (event.type, event.state_key): event
+                    for event in batch.events if event.is_state()
+                }
+
+                state = _calculate_state(
+                    timeline_contains=timeline_state,
+                    timeline_start=state_at_timeline_start,
+                    previous=state_at_previous_sync,
+                )
+            else:
+                state = {}
+
+            defer.returnValue({
+                (e.type, e.state_key): e
+                for e in sync_config.filter_collection.filter_room_state(state.values())
+            })
 
     def check_joined_room(self, sync_config, state_delta):
         """
@@ -845,3 +887,68 @@ class SyncHandler(BaseHandler):
             if join_event.content["membership"] == Membership.JOIN:
                 return True
         return False
+
+    @defer.inlineCallbacks
+    def unread_notifs_for_room_id(self, room_id, sync_config):
+        with Measure(self.clock, "unread_notifs_for_room_id"):
+            last_unread_event_id = yield self.store.get_last_receipt_event_id_for_user(
+                user_id=sync_config.user.to_string(),
+                room_id=room_id,
+                receipt_type="m.read"
+            )
+
+            notifs = []
+            if last_unread_event_id:
+                notifs = yield self.store.get_unread_event_push_actions_by_room_for_user(
+                    room_id, sync_config.user.to_string(), last_unread_event_id
+                )
+                defer.returnValue(notifs)
+
+            # There is no new information in this period, so your notification
+            # count is whatever it was last time.
+            defer.returnValue(None)
+
+
+def _action_has_highlight(actions):
+    for action in actions:
+        try:
+            if action.get("set_tweak", None) == "highlight":
+                return action.get("value", True)
+        except AttributeError:
+            pass
+
+    return False
+
+
+def _calculate_state(timeline_contains, timeline_start, previous):
+    """Works out what state to include in a sync response.
+
+    Args:
+        timeline_contains (dict): state in the timeline
+        timeline_start (dict): state at the start of the timeline
+        previous (dict): state at the end of the previous sync (or empty dict
+            if this is an initial sync)
+
+    Returns:
+        dict
+    """
+    event_id_to_state = {
+        e.event_id: e
+        for e in itertools.chain(
+            timeline_contains.values(),
+            previous.values(),
+            timeline_start.values(),
+        )
+    }
+
+    tc_ids = set(e.event_id for e in timeline_contains.values())
+    p_ids = set(e.event_id for e in previous.values())
+    ts_ids = set(e.event_id for e in timeline_start.values())
+
+    state_ids = (ts_ids - p_ids) - tc_ids
+
+    evs = (event_id_to_state[e] for e in state_ids)
+    return {
+        (e.type, e.state_key): e
+        for e in evs
+    }