Merge branch 'release-v0.19.3' of github.com:matrix-org/synapse v0.19.3

16 files changed, 812 insertions, 137 deletions

diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index b9968debe5..d604e7668f 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -297,6 +297,82 @@ class DataStore(RoomMemberStore, RoomStore,
             desc="get_user_ip_and_agents",
         )
 
+    def get_users(self):
+        """Function to reterive a list of users in users table.
+
+        Args:
+        Returns:
+            defer.Deferred: resolves to list[dict[str, Any]]
+        """
+        return self._simple_select_list(
+            table="users",
+            keyvalues={},
+            retcols=[
+                "name",
+                "password_hash",
+                "is_guest",
+                "admin"
+            ],
+            desc="get_users",
+        )
+
+    def get_users_paginate(self, order, start, limit):
+        """Function to reterive a paginated list of users from
+        users list. This will return a json object, which contains
+        list of users and the total number of users in users table.
+
+        Args:
+            order (str): column name to order the select by this column
+            start (int): start number to begin the query from
+            limit (int): number of rows to reterive
+        Returns:
+            defer.Deferred: resolves to json object {list[dict[str, Any]], count}
+        """
+        is_guest = 0
+        i_start = (int)(start)
+        i_limit = (int)(limit)
+        return self.get_user_list_paginate(
+            table="users",
+            keyvalues={
+                "is_guest": is_guest
+            },
+            pagevalues=[
+                order,
+                i_limit,
+                i_start
+            ],
+            retcols=[
+                "name",
+                "password_hash",
+                "is_guest",
+                "admin"
+            ],
+            desc="get_users_paginate",
+        )
+
+    def search_users(self, term):
+        """Function to search users list for one or more users with
+        the matched term.
+
+        Args:
+            term (str): search term
+            col (str): column to query term should be matched to
+        Returns:
+            defer.Deferred: resolves to list[dict[str, Any]]
+        """
+        return self._simple_search_list(
+            table="users",
+            term=term,
+            col="name",
+            retcols=[
+                "name",
+                "password_hash",
+                "is_guest",
+                "admin"
+            ],
+            desc="search_users",
+        )
+
 
 def are_all_users_on_domain(txn, database_engine, domain):
     sql = database_engine.convert_param_style(
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 05374682fd..a7a8ec9b7b 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -18,7 +18,6 @@ from synapse.api.errors import StoreError
 from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
 from synapse.util.caches.dictionary_cache import DictionaryCache
 from synapse.util.caches.descriptors import Cache
-from synapse.util.caches import intern_dict
 from synapse.storage.engines import PostgresEngine
 import synapse.metrics
 
@@ -80,7 +79,13 @@ class LoggingTransaction(object):
     def executemany(self, sql, *args):
         self._do_execute(self.txn.executemany, sql, *args)
 
+    def _make_sql_one_line(self, sql):
+        "Strip newlines out of SQL so that the loggers in the DB are on one line"
+        return " ".join(l.strip() for l in sql.splitlines() if l.strip())
+
     def _do_execute(self, func, sql, *args):
+        sql = self._make_sql_one_line(sql)
+
         # TODO(paul): Maybe use 'info' and 'debug' for values?
         sql_logger.debug("[SQL] {%s} %s", self.name, sql)
 
@@ -350,9 +355,9 @@ class SQLBaseStore(object):
         Returns:
             A list of dicts where the key is the column header.
         """
-        col_headers = list(column[0] for column in cursor.description)
+        col_headers = list(intern(column[0]) for column in cursor.description)
         results = list(
-            intern_dict(dict(zip(col_headers, row))) for row in cursor.fetchall()
+            dict(zip(col_headers, row)) for row in cursor.fetchall()
         )
         return results
 
@@ -483,10 +488,6 @@ class SQLBaseStore(object):
             " AND ".join("%s = ?" % (k,) for k in keyvalues)
         )
         sqlargs = values.values() + keyvalues.values()
-        logger.debug(
-            "[SQL] %s Args=%s",
-            sql, sqlargs,
-        )
 
         txn.execute(sql, sqlargs)
         if txn.rowcount == 0:
@@ -501,10 +502,6 @@ class SQLBaseStore(object):
                 ", ".join(k for k in allvalues),
                 ", ".join("?" for _ in allvalues)
             )
-            logger.debug(
-                "[SQL] %s Args=%s",
-                sql, keyvalues.values(),
-            )
             txn.execute(sql, allvalues.values())
 
             return True
@@ -934,6 +931,165 @@ class SQLBaseStore(object):
         else:
             return 0
 
+    def _simple_select_list_paginate(self, table, keyvalues, pagevalues, retcols,
+                                     desc="_simple_select_list_paginate"):
+        """Executes a SELECT query on the named table with start and limit,
+        of row numbers, which may return zero or number of rows from start to limit,
+        returning the result as a list of dicts.
+
+        Args:
+            table (str): the table name
+            keyvalues (dict[str, Any] | None):
+                column names and values to select the rows with, or None to not
+                apply a WHERE clause.
+            retcols (iterable[str]): the names of the columns to return
+            order (str): order the select by this column
+            start (int): start number to begin the query from
+            limit (int): number of rows to reterive
+        Returns:
+            defer.Deferred: resolves to list[dict[str, Any]]
+        """
+        return self.runInteraction(
+            desc,
+            self._simple_select_list_paginate_txn,
+            table, keyvalues, pagevalues, retcols
+        )
+
+    @classmethod
+    def _simple_select_list_paginate_txn(cls, txn, table, keyvalues, pagevalues, retcols):
+        """Executes a SELECT query on the named table with start and limit,
+        of row numbers, which may return zero or number of rows from start to limit,
+        returning the result as a list of dicts.
+
+        Args:
+            txn : Transaction object
+            table (str): the table name
+            keyvalues (dict[str, T] | None):
+                column names and values to select the rows with, or None to not
+                apply a WHERE clause.
+            pagevalues ([]):
+                order (str): order the select by this column
+                start (int): start number to begin the query from
+                limit (int): number of rows to reterive
+            retcols (iterable[str]): the names of the columns to return
+        Returns:
+            defer.Deferred: resolves to list[dict[str, Any]]
+
+        """
+        if keyvalues:
+            sql = "SELECT %s FROM %s WHERE %s ORDER BY %s" % (
+                ", ".join(retcols),
+                table,
+                " AND ".join("%s = ?" % (k,) for k in keyvalues),
+                " ? ASC LIMIT ? OFFSET ?"
+            )
+            txn.execute(sql, keyvalues.values() + pagevalues)
+        else:
+            sql = "SELECT %s FROM %s ORDER BY %s" % (
+                ", ".join(retcols),
+                table,
+                " ? ASC LIMIT ? OFFSET ?"
+            )
+            txn.execute(sql, pagevalues)
+
+        return cls.cursor_to_dict(txn)
+
+    @defer.inlineCallbacks
+    def get_user_list_paginate(self, table, keyvalues, pagevalues, retcols,
+                               desc="get_user_list_paginate"):
+        """Get a list of users from start row to a limit number of rows. This will
+        return a json object with users and total number of users in users list.
+
+        Args:
+            table (str): the table name
+            keyvalues (dict[str, Any] | None):
+                column names and values to select the rows with, or None to not
+                apply a WHERE clause.
+            pagevalues ([]):
+                order (str): order the select by this column
+                start (int): start number to begin the query from
+                limit (int): number of rows to reterive
+            retcols (iterable[str]): the names of the columns to return
+        Returns:
+            defer.Deferred: resolves to json object {list[dict[str, Any]], count}
+        """
+        users = yield self.runInteraction(
+            desc,
+            self._simple_select_list_paginate_txn,
+            table, keyvalues, pagevalues, retcols
+        )
+        count = yield self.runInteraction(
+            desc,
+            self.get_user_count_txn
+        )
+        retval = {
+            "users": users,
+            "total": count
+        }
+        defer.returnValue(retval)
+
+    def get_user_count_txn(self, txn):
+        """Get a total number of registerd users in the users list.
+
+        Args:
+            txn : Transaction object
+        Returns:
+            defer.Deferred: resolves to int
+        """
+        sql_count = "SELECT COUNT(*) FROM users WHERE is_guest = 0;"
+        txn.execute(sql_count)
+        count = txn.fetchone()[0]
+        defer.returnValue(count)
+
+    def _simple_search_list(self, table, term, col, retcols,
+                            desc="_simple_search_list"):
+        """Executes a SELECT query on the named table, which may return zero or
+        more rows, returning the result as a list of dicts.
+
+        Args:
+            table (str): the table name
+            term (str | None):
+                term for searching the table matched to a column.
+            col (str): column to query term should be matched to
+            retcols (iterable[str]): the names of the columns to return
+        Returns:
+            defer.Deferred: resolves to list[dict[str, Any]] or None
+        """
+
+        return self.runInteraction(
+            desc,
+            self._simple_search_list_txn,
+            table, term, col, retcols
+        )
+
+    @classmethod
+    def _simple_search_list_txn(cls, txn, table, term, col, retcols):
+        """Executes a SELECT query on the named table, which may return zero or
+        more rows, returning the result as a list of dicts.
+
+        Args:
+            txn : Transaction object
+            table (str): the table name
+            term (str | None):
+                term for searching the table matched to a column.
+            col (str): column to query term should be matched to
+            retcols (iterable[str]): the names of the columns to return
+        Returns:
+            defer.Deferred: resolves to list[dict[str, Any]] or None
+        """
+        if term:
+            sql = "SELECT %s FROM %s WHERE %s LIKE ?" % (
+                ", ".join(retcols),
+                table,
+                col
+            )
+            termvalues = ["%%" + term + "%%"]
+            txn.execute(sql, termvalues)
+        else:
+            return 0
+
+        return cls.cursor_to_dict(txn)
+
 
 class _RollbackButIsFineException(Exception):
     """ This exception is used to rollback a transaction without implying
diff --git a/synapse/storage/deviceinbox.py b/synapse/storage/deviceinbox.py
index bde3b5cbbc..5c7db5e5f6 100644
--- a/synapse/storage/deviceinbox.py
+++ b/synapse/storage/deviceinbox.py
@@ -20,6 +20,8 @@ from twisted.internet import defer
 
 from .background_updates import BackgroundUpdateStore
 
+from synapse.util.caches.expiringcache import ExpiringCache
+
 
 logger = logging.getLogger(__name__)
 
@@ -42,6 +44,15 @@ class DeviceInboxStore(BackgroundUpdateStore):
             self._background_drop_index_device_inbox,
         )
 
+        # Map of (user_id, device_id) to the last stream_id that has been
+        # deleted up to. This is so that we can no op deletions.
+        self._last_device_delete_cache = ExpiringCache(
+            cache_name="last_device_delete_cache",
+            clock=self._clock,
+            max_len=10000,
+            expiry_ms=30 * 60 * 1000,
+        )
+
     @defer.inlineCallbacks
     def add_messages_to_device_inbox(self, local_messages_by_user_then_device,
                                      remote_messages_by_destination):
@@ -251,6 +262,7 @@ class DeviceInboxStore(BackgroundUpdateStore):
             "get_new_messages_for_device", get_new_messages_for_device_txn,
         )
 
+    @defer.inlineCallbacks
     def delete_messages_for_device(self, user_id, device_id, up_to_stream_id):
         """
         Args:
@@ -260,6 +272,18 @@ class DeviceInboxStore(BackgroundUpdateStore):
         Returns:
             A deferred that resolves to the number of messages deleted.
         """
+        # If we have cached the last stream id we've deleted up to, we can
+        # check if there is likely to be anything that needs deleting
+        last_deleted_stream_id = self._last_device_delete_cache.get(
+            (user_id, device_id), None
+        )
+        if last_deleted_stream_id:
+            has_changed = self._device_inbox_stream_cache.has_entity_changed(
+                user_id, last_deleted_stream_id
+            )
+            if not has_changed:
+                defer.returnValue(0)
+
         def delete_messages_for_device_txn(txn):
             sql = (
                 "DELETE FROM device_inbox"
@@ -269,10 +293,20 @@ class DeviceInboxStore(BackgroundUpdateStore):
             txn.execute(sql, (user_id, device_id, up_to_stream_id))
             return txn.rowcount
 
-        return self.runInteraction(
+        count = yield self.runInteraction(
             "delete_messages_for_device", delete_messages_for_device_txn
         )
 
+        # Update the cache, ensuring that we only ever increase the value
+        last_deleted_stream_id = self._last_device_delete_cache.get(
+            (user_id, device_id), 0
+        )
+        self._last_device_delete_cache[(user_id, device_id)] = max(
+            last_deleted_stream_id, up_to_stream_id
+        )
+
+        defer.returnValue(count)
+
     def get_all_new_device_messages(self, last_pos, current_pos, limit):
         """
         Args:
diff --git a/synapse/storage/devices.py b/synapse/storage/devices.py
index 8e17800364..bd56ba2515 100644
--- a/synapse/storage/devices.py
+++ b/synapse/storage/devices.py
@@ -19,6 +19,8 @@ from twisted.internet import defer
 
 from synapse.api.errors import StoreError
 from ._base import SQLBaseStore
+from synapse.util.caches.descriptors import cached, cachedList, cachedInlineCallbacks
+
 
 logger = logging.getLogger(__name__)
 
@@ -31,6 +33,13 @@ class DeviceStore(SQLBaseStore):
             self._prune_old_outbound_device_pokes, 60 * 60 * 1000
         )
 
+        self.register_background_index_update(
+            "device_lists_stream_idx",
+            index_name="device_lists_stream_user_id",
+            table="device_lists_stream",
+            columns=["user_id", "device_id"],
+        )
+
     @defer.inlineCallbacks
     def store_device(self, user_id, device_id,
                      initial_device_display_name):
@@ -144,6 +153,7 @@ class DeviceStore(SQLBaseStore):
 
         defer.returnValue({d["device_id"]: d for d in devices})
 
+    @cached(max_entries=10000)
     def get_device_list_last_stream_id_for_remote(self, user_id):
         """Get the last stream_id we got for a user. May be None if we haven't
         got any information for them.
@@ -156,16 +166,36 @@ class DeviceStore(SQLBaseStore):
             allow_none=True,
         )
 
+    @cachedList(cached_method_name="get_device_list_last_stream_id_for_remote",
+                list_name="user_ids", inlineCallbacks=True)
+    def get_device_list_last_stream_id_for_remotes(self, user_ids):
+        rows = yield self._simple_select_many_batch(
+            table="device_lists_remote_extremeties",
+            column="user_id",
+            iterable=user_ids,
+            retcols=("user_id", "stream_id",),
+            desc="get_user_devices_from_cache",
+        )
+
+        results = {user_id: None for user_id in user_ids}
+        results.update({
+            row["user_id"]: row["stream_id"] for row in rows
+        })
+
+        defer.returnValue(results)
+
+    @defer.inlineCallbacks
     def mark_remote_user_device_list_as_unsubscribed(self, user_id):
         """Mark that we no longer track device lists for remote user.
         """
-        return self._simple_delete(
+        yield self._simple_delete(
             table="device_lists_remote_extremeties",
             keyvalues={
                 "user_id": user_id,
             },
             desc="mark_remote_user_device_list_as_unsubscribed",
         )
+        self.get_device_list_last_stream_id_for_remote.invalidate((user_id,))
 
     def update_remote_device_list_cache_entry(self, user_id, device_id, content,
                                               stream_id):
@@ -191,6 +221,12 @@ class DeviceStore(SQLBaseStore):
             }
         )
 
+        txn.call_after(self._get_cached_user_device.invalidate, (user_id, device_id,))
+        txn.call_after(self._get_cached_devices_for_user.invalidate, (user_id,))
+        txn.call_after(
+            self.get_device_list_last_stream_id_for_remote.invalidate, (user_id,)
+        )
+
         self._simple_upsert_txn(
             txn,
             table="device_lists_remote_extremeties",
@@ -234,6 +270,12 @@ class DeviceStore(SQLBaseStore):
             ]
         )
 
+        txn.call_after(self._get_cached_devices_for_user.invalidate, (user_id,))
+        txn.call_after(self._get_cached_user_device.invalidate_many, (user_id,))
+        txn.call_after(
+            self.get_device_list_last_stream_id_for_remote.invalidate, (user_id,)
+        )
+
         self._simple_upsert_txn(
             txn,
             table="device_lists_remote_extremeties",
@@ -320,6 +362,7 @@ class DeviceStore(SQLBaseStore):
 
         return (now_stream_id, results)
 
+    @defer.inlineCallbacks
     def get_user_devices_from_cache(self, query_list):
         """Get the devices (and keys if any) for remote users from the cache.
 
@@ -332,27 +375,11 @@ class DeviceStore(SQLBaseStore):
             a set of user_ids and results_map is a mapping of
             user_id -> device_id -> device_info
         """
-        return self.runInteraction(
-            "get_user_devices_from_cache", self._get_user_devices_from_cache_txn,
-            query_list,
+        user_ids = set(user_id for user_id, _ in query_list)
+        user_map = yield self.get_device_list_last_stream_id_for_remotes(list(user_ids))
+        user_ids_in_cache = set(
+            user_id for user_id, stream_id in user_map.items() if stream_id
         )
-
-    def _get_user_devices_from_cache_txn(self, txn, query_list):
-        user_ids = {user_id for user_id, _ in query_list}
-
-        user_ids_in_cache = set()
-        for user_id in user_ids:
-            stream_ids = self._simple_select_onecol_txn(
-                txn,
-                table="device_lists_remote_extremeties",
-                keyvalues={
-                    "user_id": user_id,
-                },
-                retcol="stream_id",
-            )
-            if stream_ids:
-                user_ids_in_cache.add(user_id)
-
         user_ids_not_in_cache = user_ids - user_ids_in_cache
 
         results = {}
@@ -361,32 +388,40 @@ class DeviceStore(SQLBaseStore):
                 continue
 
             if device_id:
-                content = self._simple_select_one_onecol_txn(
-                    txn,
-                    table="device_lists_remote_cache",
-                    keyvalues={
-                        "user_id": user_id,
-                        "device_id": device_id,
-                    },
-                    retcol="content",
-                )
-                results.setdefault(user_id, {})[device_id] = json.loads(content)
+                device = yield self._get_cached_user_device(user_id, device_id)
+                results.setdefault(user_id, {})[device_id] = device
             else:
-                devices = self._simple_select_list_txn(
-                    txn,
-                    table="device_lists_remote_cache",
-                    keyvalues={
-                        "user_id": user_id,
-                    },
-                    retcols=("device_id", "content"),
-                )
-                results[user_id] = {
-                    device["device_id"]: json.loads(device["content"])
-                    for device in devices
-                }
-                user_ids_in_cache.discard(user_id)
+                results[user_id] = yield self._get_cached_devices_for_user(user_id)
+
+        defer.returnValue((user_ids_not_in_cache, results))
+
+    @cachedInlineCallbacks(num_args=2, tree=True)
+    def _get_cached_user_device(self, user_id, device_id):
+        content = yield self._simple_select_one_onecol(
+            table="device_lists_remote_cache",
+            keyvalues={
+                "user_id": user_id,
+                "device_id": device_id,
+            },
+            retcol="content",
+            desc="_get_cached_user_device",
+        )
+        defer.returnValue(json.loads(content))
 
-        return user_ids_not_in_cache, results
+    @cachedInlineCallbacks()
+    def _get_cached_devices_for_user(self, user_id):
+        devices = yield self._simple_select_list(
+            table="device_lists_remote_cache",
+            keyvalues={
+                "user_id": user_id,
+            },
+            retcols=("device_id", "content"),
+            desc="_get_cached_devices_for_user",
+        )
+        defer.returnValue({
+            device["device_id"]: json.loads(device["content"])
+            for device in devices
+        })
 
     def get_devices_with_keys_by_user(self, user_id):
         """Get all devices (with any device keys) for a user
@@ -473,7 +508,7 @@ class DeviceStore(SQLBaseStore):
             defer.returnValue(set(changed))
 
         sql = """
-            SELECT user_id FROM device_lists_stream WHERE stream_id > ?
+            SELECT DISTINCT user_id FROM device_lists_stream WHERE stream_id > ?
         """
         rows = yield self._execute("get_user_whose_devices_changed", None, sql, from_key)
         defer.returnValue(set(row[0] for row in rows))
@@ -489,7 +524,7 @@ class DeviceStore(SQLBaseStore):
             WHERE stream_id > ?
         """
         return self._execute(
-            "get_users_and_hosts_device_list", None,
+            "get_all_device_list_changes_for_remotes", None,
             sql, from_key,
         )
 
@@ -518,6 +553,16 @@ class DeviceStore(SQLBaseStore):
                 host, stream_id,
             )
 
+        # Delete older entries in the table, as we really only care about
+        # when the latest change happened.
+        txn.executemany(
+            """
+            DELETE FROM device_lists_stream
+            WHERE user_id = ? AND device_id = ? AND stream_id < ?
+            """,
+            [(user_id, device_id, stream_id) for device_id in device_ids]
+        )
+
         self._simple_insert_many_txn(
             txn,
             table="device_lists_stream",
diff --git a/synapse/storage/end_to_end_keys.py b/synapse/storage/end_to_end_keys.py
index 2040e022fa..b9f1365f92 100644
--- a/synapse/storage/end_to_end_keys.py
+++ b/synapse/storage/end_to_end_keys.py
@@ -93,7 +93,7 @@ class EndToEndKeyStore(SQLBaseStore):
             query_clause = "user_id = ?"
             query_params.append(user_id)
 
-            if device_id:
+            if device_id is not None:
                 query_clause += " AND device_id = ?"
                 query_params.append(device_id)
 
diff --git a/synapse/storage/event_federation.py b/synapse/storage/event_federation.py
index ee88c61954..256e50dc20 100644
--- a/synapse/storage/event_federation.py
+++ b/synapse/storage/event_federation.py
@@ -281,15 +281,30 @@ class EventFederationStore(SQLBaseStore):
         )
 
     def get_forward_extremeties_for_room(self, room_id, stream_ordering):
+        """For a given room_id and stream_ordering, return the forward
+        extremeties of the room at that point in "time".
+
+        Throws a StoreError if we have since purged the index for
+        stream_orderings from that point.
+
+        Args:
+            room_id (str):
+            stream_ordering (int):
+
+        Returns:
+            deferred, which resolves to a list of event_ids
+        """
         # We want to make the cache more effective, so we clamp to the last
         # change before the given ordering.
         last_change = self._events_stream_cache.get_max_pos_of_last_change(room_id)
 
         # We don't always have a full stream_to_exterm_id table, e.g. after
         # the upgrade that introduced it, so we make sure we never ask for a
-        # try and pin to a stream_ordering from before a restart
+        # stream_ordering from before a restart
         last_change = max(self._stream_order_on_start, last_change)
 
+        # provided the last_change is recent enough, we now clamp the requested
+        # stream_ordering to it.
         if last_change > self.stream_ordering_month_ago:
             stream_ordering = min(last_change, stream_ordering)
 
diff --git a/synapse/storage/event_push_actions.py b/synapse/storage/event_push_actions.py
index 7de3e8c58c..14543b4269 100644
--- a/synapse/storage/event_push_actions.py
+++ b/synapse/storage/event_push_actions.py
@@ -15,6 +15,7 @@
 
 from ._base import SQLBaseStore
 from twisted.internet import defer
+from synapse.util.async import sleep
 from synapse.util.caches.descriptors import cachedInlineCallbacks
 from synapse.types import RoomStreamToken
 from .stream import lower_bound
@@ -25,11 +26,46 @@ import ujson as json
 logger = logging.getLogger(__name__)
 
 
+DEFAULT_NOTIF_ACTION = ["notify", {"set_tweak": "highlight", "value": False}]
+DEFAULT_HIGHLIGHT_ACTION = [
+    "notify", {"set_tweak": "sound", "value": "default"}, {"set_tweak": "highlight"}
+]
+
+
+def _serialize_action(actions, is_highlight):
+    """Custom serializer for actions. This allows us to "compress" common actions.
+
+    We use the fact that most users have the same actions for notifs (and for
+    highlights).
+    We store these default actions as the empty string rather than the full JSON.
+    Since the empty string isn't valid JSON there is no risk of this clashing with
+    any real JSON actions
+    """
+    if is_highlight:
+        if actions == DEFAULT_HIGHLIGHT_ACTION:
+            return ""  # We use empty string as the column is non-NULL
+    else:
+        if actions == DEFAULT_NOTIF_ACTION:
+            return ""
+    return json.dumps(actions)
+
+
+def _deserialize_action(actions, is_highlight):
+    """Custom deserializer for actions. This allows us to "compress" common actions
+    """
+    if actions:
+        return json.loads(actions)
+
+    if is_highlight:
+        return DEFAULT_HIGHLIGHT_ACTION
+    else:
+        return DEFAULT_NOTIF_ACTION
+
+
 class EventPushActionsStore(SQLBaseStore):
     EPA_HIGHLIGHT_INDEX = "epa_highlight_index"
 
     def __init__(self, hs):
-        self.stream_ordering_month_ago = None
         super(EventPushActionsStore, self).__init__(hs)
 
         self.register_background_index_update(
@@ -47,6 +83,11 @@ class EventPushActionsStore(SQLBaseStore):
             where_clause="highlight=1"
         )
 
+        self._doing_notif_rotation = False
+        self._rotate_notif_loop = self._clock.looping_call(
+            self._rotate_notifs, 30 * 60 * 1000
+        )
+
     def _set_push_actions_for_event_and_users_txn(self, txn, event, tuples):
         """
         Args:
@@ -55,15 +96,17 @@ class EventPushActionsStore(SQLBaseStore):
         """
         values = []
         for uid, actions in tuples:
+            is_highlight = 1 if _action_has_highlight(actions) else 0
+
             values.append({
                 'room_id': event.room_id,
                 'event_id': event.event_id,
                 'user_id': uid,
-                'actions': json.dumps(actions),
+                'actions': _serialize_action(actions, is_highlight),
                 'stream_ordering': event.internal_metadata.stream_ordering,
                 'topological_ordering': event.depth,
                 'notif': 1,
-                'highlight': 1 if _action_has_highlight(actions) else 0,
+                'highlight': is_highlight,
             })
 
         for uid, __ in tuples:
@@ -77,66 +120,83 @@ class EventPushActionsStore(SQLBaseStore):
     def get_unread_event_push_actions_by_room_for_user(
             self, room_id, user_id, last_read_event_id
     ):
-        def _get_unread_event_push_actions_by_room(txn):
-            sql = (
-                "SELECT stream_ordering, topological_ordering"
-                " FROM events"
-                " WHERE room_id = ? AND event_id = ?"
-            )
-            txn.execute(
-                sql, (room_id, last_read_event_id)
-            )
-            results = txn.fetchall()
-            if len(results) == 0:
-                return {"notify_count": 0, "highlight_count": 0}
-
-            stream_ordering = results[0][0]
-            topological_ordering = results[0][1]
-            token = RoomStreamToken(
-                topological_ordering, stream_ordering
-            )
-
-            # First get number of notifications.
-            # We don't need to put a notif=1 clause as all rows always have
-            # notif=1
-            sql = (
-                "SELECT count(*)"
-                " FROM event_push_actions ea"
-                " WHERE"
-                " user_id = ?"
-                " AND room_id = ?"
-                " AND %s"
-            ) % (lower_bound(token, self.database_engine, inclusive=False),)
-
-            txn.execute(sql, (user_id, room_id))
-            row = txn.fetchone()
-            notify_count = row[0] if row else 0
+        ret = yield self.runInteraction(
+            "get_unread_event_push_actions_by_room",
+            self._get_unread_counts_by_receipt_txn,
+            room_id, user_id, last_read_event_id
+        )
+        defer.returnValue(ret)
 
-            # Now get the number of highlights
-            sql = (
-                "SELECT count(*)"
-                " FROM event_push_actions ea"
-                " WHERE"
-                " highlight = 1"
-                " AND user_id = ?"
-                " AND room_id = ?"
-                " AND %s"
-            ) % (lower_bound(token, self.database_engine, inclusive=False),)
+    def _get_unread_counts_by_receipt_txn(self, txn, room_id, user_id,
+                                          last_read_event_id):
+        sql = (
+            "SELECT stream_ordering, topological_ordering"
+            " FROM events"
+            " WHERE room_id = ? AND event_id = ?"
+        )
+        txn.execute(
+            sql, (room_id, last_read_event_id)
+        )
+        results = txn.fetchall()
+        if len(results) == 0:
+            return {"notify_count": 0, "highlight_count": 0}
 
-            txn.execute(sql, (user_id, room_id))
-            row = txn.fetchone()
-            highlight_count = row[0] if row else 0
+        stream_ordering = results[0][0]
+        topological_ordering = results[0][1]
 
-            return {
-                "notify_count": notify_count,
-                "highlight_count": highlight_count,
-            }
+        return self._get_unread_counts_by_pos_txn(
+            txn, room_id, user_id, topological_ordering, stream_ordering
+        )
 
-        ret = yield self.runInteraction(
-            "get_unread_event_push_actions_by_room",
-            _get_unread_event_push_actions_by_room
+    def _get_unread_counts_by_pos_txn(self, txn, room_id, user_id, topological_ordering,
+                                      stream_ordering):
+        token = RoomStreamToken(
+            topological_ordering, stream_ordering
         )
-        defer.returnValue(ret)
+
+        # First get number of notifications.
+        # We don't need to put a notif=1 clause as all rows always have
+        # notif=1
+        sql = (
+            "SELECT count(*)"
+            " FROM event_push_actions ea"
+            " WHERE"
+            " user_id = ?"
+            " AND room_id = ?"
+            " AND %s"
+        ) % (lower_bound(token, self.database_engine, inclusive=False),)
+
+        txn.execute(sql, (user_id, room_id))
+        row = txn.fetchone()
+        notify_count = row[0] if row else 0
+
+        txn.execute("""
+            SELECT notif_count FROM event_push_summary
+            WHERE room_id = ? AND user_id = ? AND stream_ordering > ?
+        """, (room_id, user_id, stream_ordering,))
+        rows = txn.fetchall()
+        if rows:
+            notify_count += rows[0][0]
+
+        # Now get the number of highlights
+        sql = (
+            "SELECT count(*)"
+            " FROM event_push_actions ea"
+            " WHERE"
+            " highlight = 1"
+            " AND user_id = ?"
+            " AND room_id = ?"
+            " AND %s"
+        ) % (lower_bound(token, self.database_engine, inclusive=False),)
+
+        txn.execute(sql, (user_id, room_id))
+        row = txn.fetchone()
+        highlight_count = row[0] if row else 0
+
+        return {
+            "notify_count": notify_count,
+            "highlight_count": highlight_count,
+        }
 
     @defer.inlineCallbacks
     def get_push_action_users_in_range(self, min_stream_ordering, max_stream_ordering):
@@ -176,7 +236,8 @@ class EventPushActionsStore(SQLBaseStore):
             # find rooms that have a read receipt in them and return the next
             # push actions
             sql = (
-                "SELECT ep.event_id, ep.room_id, ep.stream_ordering, ep.actions"
+                "SELECT ep.event_id, ep.room_id, ep.stream_ordering, ep.actions,"
+                "   ep.highlight "
                 " FROM ("
                 "   SELECT room_id,"
                 "       MAX(topological_ordering) as topological_ordering,"
@@ -217,7 +278,7 @@ class EventPushActionsStore(SQLBaseStore):
         def get_no_receipt(txn):
             sql = (
                 "SELECT ep.event_id, ep.room_id, ep.stream_ordering, ep.actions,"
-                " e.received_ts"
+                "   ep.highlight "
                 " FROM event_push_actions AS ep"
                 " INNER JOIN events AS e USING (room_id, event_id)"
                 " WHERE"
@@ -246,7 +307,7 @@ class EventPushActionsStore(SQLBaseStore):
                 "event_id": row[0],
                 "room_id": row[1],
                 "stream_ordering": row[2],
-                "actions": json.loads(row[3]),
+                "actions": _deserialize_action(row[3], row[4]),
             } for row in after_read_receipt + no_read_receipt
         ]
 
@@ -285,7 +346,7 @@ class EventPushActionsStore(SQLBaseStore):
         def get_after_receipt(txn):
             sql = (
                 "SELECT ep.event_id, ep.room_id, ep.stream_ordering, ep.actions,"
-                "  e.received_ts"
+                "  ep.highlight, e.received_ts"
                 " FROM ("
                 "   SELECT room_id,"
                 "       MAX(topological_ordering) as topological_ordering,"
@@ -327,7 +388,7 @@ class EventPushActionsStore(SQLBaseStore):
         def get_no_receipt(txn):
             sql = (
                 "SELECT ep.event_id, ep.room_id, ep.stream_ordering, ep.actions,"
-                " e.received_ts"
+                "   ep.highlight, e.received_ts"
                 " FROM event_push_actions AS ep"
                 " INNER JOIN events AS e USING (room_id, event_id)"
                 " WHERE"
@@ -357,8 +418,8 @@ class EventPushActionsStore(SQLBaseStore):
                 "event_id": row[0],
                 "room_id": row[1],
                 "stream_ordering": row[2],
-                "actions": json.loads(row[3]),
-                "received_ts": row[4],
+                "actions": _deserialize_action(row[3], row[4]),
+                "received_ts": row[5],
             } for row in after_read_receipt + no_read_receipt
         ]
 
@@ -392,7 +453,7 @@ class EventPushActionsStore(SQLBaseStore):
             sql = (
                 "SELECT epa.event_id, epa.room_id,"
                 " epa.stream_ordering, epa.topological_ordering,"
-                " epa.actions, epa.profile_tag, e.received_ts"
+                " epa.actions, epa.highlight, epa.profile_tag, e.received_ts"
                 " FROM event_push_actions epa, events e"
                 " WHERE epa.event_id = e.event_id"
                 " AND epa.user_id = ? %s"
@@ -407,7 +468,7 @@ class EventPushActionsStore(SQLBaseStore):
             "get_push_actions_for_user", f
         )
         for pa in push_actions:
-            pa["actions"] = json.loads(pa["actions"])
+            pa["actions"] = _deserialize_action(pa["actions"], pa["highlight"])
         defer.returnValue(push_actions)
 
     @defer.inlineCallbacks
@@ -448,10 +509,14 @@ class EventPushActionsStore(SQLBaseStore):
         )
 
     def _remove_old_push_actions_before_txn(self, txn, room_id, user_id,
-                                            topological_ordering):
+                                            topological_ordering, stream_ordering):
         """
-        Purges old, stale push actions for a user and room before a given
-        topological_ordering
+        Purges old push actions for a user and room before a given
+        topological_ordering.
+
+        We however keep a months worth of highlighted notifications, so that
+        users can still get a list of recent highlights.
+
         Args:
             txn: The transcation
             room_id: Room ID to delete from
@@ -475,10 +540,16 @@ class EventPushActionsStore(SQLBaseStore):
         txn.execute(
             "DELETE FROM event_push_actions "
             " WHERE user_id = ? AND room_id = ? AND "
-            " topological_ordering < ? AND stream_ordering < ?",
+            " topological_ordering <= ?"
+            " AND ((stream_ordering < ? AND highlight = 1) or highlight = 0)",
             (user_id, room_id, topological_ordering, self.stream_ordering_month_ago)
         )
 
+        txn.execute("""
+            DELETE FROM event_push_summary
+            WHERE room_id = ? AND user_id = ? AND stream_ordering <= ?
+        """, (room_id, user_id, stream_ordering))
+
     @defer.inlineCallbacks
     def _find_stream_orderings_for_times(self):
         yield self.runInteraction(
@@ -495,6 +566,14 @@ class EventPushActionsStore(SQLBaseStore):
             "Found stream ordering 1 month ago: it's %d",
             self.stream_ordering_month_ago
         )
+        logger.info("Searching for stream ordering 1 day ago")
+        self.stream_ordering_day_ago = self._find_first_stream_ordering_after_ts_txn(
+            txn, self._clock.time_msec() - 24 * 60 * 60 * 1000
+        )
+        logger.info(
+            "Found stream ordering 1 day ago: it's %d",
+            self.stream_ordering_day_ago
+        )
 
     def _find_first_stream_ordering_after_ts_txn(self, txn, ts):
         """
@@ -534,6 +613,131 @@ class EventPushActionsStore(SQLBaseStore):
 
         return range_end
 
+    @defer.inlineCallbacks
+    def _rotate_notifs(self):
+        if self._doing_notif_rotation or self.stream_ordering_day_ago is None:
+            return
+        self._doing_notif_rotation = True
+
+        try:
+            while True:
+                logger.info("Rotating notifications")
+
+                caught_up = yield self.runInteraction(
+                    "_rotate_notifs",
+                    self._rotate_notifs_txn
+                )
+                if caught_up:
+                    break
+                yield sleep(5)
+        finally:
+            self._doing_notif_rotation = False
+
+    def _rotate_notifs_txn(self, txn):
+        """Archives older notifications into event_push_summary. Returns whether
+        the archiving process has caught up or not.
+        """
+
+        old_rotate_stream_ordering = self._simple_select_one_onecol_txn(
+            txn,
+            table="event_push_summary_stream_ordering",
+            keyvalues={},
+            retcol="stream_ordering",
+        )
+
+        # We don't to try and rotate millions of rows at once, so we cap the
+        # maximum stream ordering we'll rotate before.
+        txn.execute("""
+            SELECT stream_ordering FROM event_push_actions
+            WHERE stream_ordering > ?
+            ORDER BY stream_ordering ASC LIMIT 1 OFFSET 50000
+        """, (old_rotate_stream_ordering,))
+        stream_row = txn.fetchone()
+        if stream_row:
+            offset_stream_ordering, = stream_row
+            rotate_to_stream_ordering = min(
+                self.stream_ordering_day_ago, offset_stream_ordering
+            )
+            caught_up = offset_stream_ordering >= self.stream_ordering_day_ago
+        else:
+            rotate_to_stream_ordering = self.stream_ordering_day_ago
+            caught_up = True
+
+        logger.info("Rotating notifications up to: %s", rotate_to_stream_ordering)
+
+        self._rotate_notifs_before_txn(txn, rotate_to_stream_ordering)
+
+        # We have caught up iff we were limited by `stream_ordering_day_ago`
+        return caught_up
+
+    def _rotate_notifs_before_txn(self, txn, rotate_to_stream_ordering):
+        old_rotate_stream_ordering = self._simple_select_one_onecol_txn(
+            txn,
+            table="event_push_summary_stream_ordering",
+            keyvalues={},
+            retcol="stream_ordering",
+        )
+
+        # Calculate the new counts that should be upserted into event_push_summary
+        sql = """
+            SELECT user_id, room_id,
+                coalesce(old.notif_count, 0) + upd.notif_count,
+                upd.stream_ordering,
+                old.user_id
+            FROM (
+                SELECT user_id, room_id, count(*) as notif_count,
+                    max(stream_ordering) as stream_ordering
+                FROM event_push_actions
+                WHERE ? <= stream_ordering AND stream_ordering < ?
+                    AND highlight = 0
+                GROUP BY user_id, room_id
+            ) AS upd
+            LEFT JOIN event_push_summary AS old USING (user_id, room_id)
+        """
+
+        txn.execute(sql, (old_rotate_stream_ordering, rotate_to_stream_ordering,))
+        rows = txn.fetchall()
+
+        logger.info("Rotating notifications, handling %d rows", len(rows))
+
+        # If the `old.user_id` above is NULL then we know there isn't already an
+        # entry in the table, so we simply insert it. Otherwise we update the
+        # existing table.
+        self._simple_insert_many_txn(
+            txn,
+            table="event_push_summary",
+            values=[
+                {
+                    "user_id": row[0],
+                    "room_id": row[1],
+                    "notif_count": row[2],
+                    "stream_ordering": row[3],
+                }
+                for row in rows if row[4] is None
+            ]
+        )
+
+        txn.executemany(
+            """
+                UPDATE event_push_summary SET notif_count = ?, stream_ordering = ?
+                WHERE user_id = ? AND room_id = ?
+            """,
+            ((row[2], row[3], row[0], row[1],) for row in rows if row[4] is not None)
+        )
+
+        txn.execute(
+            "DELETE FROM event_push_actions"
+            " WHERE ? <= stream_ordering AND stream_ordering < ? AND highlight = 0",
+            (old_rotate_stream_ordering, rotate_to_stream_ordering,)
+        )
+
+        logger.info("Rotating notifications, deleted %s push actions", txn.rowcount)
+
+        txn.execute(
+            "UPDATE event_push_summary_stream_ordering SET stream_ordering = ?",
+            (rotate_to_stream_ordering,)
+        )
+
 
 def _action_has_highlight(actions):
     for action in actions:
diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index c88f689d3a..db01eb6d14 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -311,6 +311,21 @@ class EventsStore(SQLBaseStore):
 
                             new_forward_extremeties[room_id] = new_latest_event_ids
 
+                            len_1 = (
+                                len(latest_event_ids) == 1
+                                and len(new_latest_event_ids) == 1
+                            )
+                            if len_1:
+                                all_single_prev_not_state = all(
+                                    len(event.prev_events) == 1
+                                    and not event.is_state()
+                                    for event, ctx in ev_ctx_rm
+                                )
+                                # Don't bother calculating state if they're just
+                                # a long chain of single ancestor non-state events.
+                                if all_single_prev_not_state:
+                                    continue
+
                             state = yield self._calculate_state_delta(
                                 room_id, ev_ctx_rm, new_latest_event_ids
                             )
diff --git a/synapse/storage/prepare_database.py b/synapse/storage/prepare_database.py
index b357f22be7..ed84db6b4b 100644
--- a/synapse/storage/prepare_database.py
+++ b/synapse/storage/prepare_database.py
@@ -25,7 +25,7 @@ logger = logging.getLogger(__name__)
 
 # Remember to update this number every time a change is made to database
 # schema files, so the users will be informed on server restarts.
-SCHEMA_VERSION = 40
+SCHEMA_VERSION = 41
 
 dir_path = os.path.abspath(os.path.dirname(__file__))
 
diff --git a/synapse/storage/presence.py b/synapse/storage/presence.py
index 7460f98a1f..4d1590d2b4 100644
--- a/synapse/storage/presence.py
+++ b/synapse/storage/presence.py
@@ -15,7 +15,7 @@
 
 from ._base import SQLBaseStore
 from synapse.api.constants import PresenceState
-from synapse.util.caches.descriptors import cached, cachedInlineCallbacks
+from synapse.util.caches.descriptors import cached, cachedInlineCallbacks, cachedList
 
 from collections import namedtuple
 from twisted.internet import defer
@@ -85,6 +85,9 @@ class PresenceStore(SQLBaseStore):
                 self.presence_stream_cache.entity_has_changed,
                 state.user_id, stream_id,
             )
+            self._invalidate_cache_and_stream(
+                txn, self._get_presence_for_user, (state.user_id,)
+            )
 
         # Actually insert new rows
         self._simple_insert_many_txn(
@@ -143,7 +146,12 @@ class PresenceStore(SQLBaseStore):
             "get_all_presence_updates", get_all_presence_updates_txn
         )
 
-    @defer.inlineCallbacks
+    @cached()
+    def _get_presence_for_user(self, user_id):
+        raise NotImplementedError()
+
+    @cachedList(cached_method_name="_get_presence_for_user", list_name="user_ids",
+                num_args=1, inlineCallbacks=True)
     def get_presence_for_users(self, user_ids):
         rows = yield self._simple_select_many_batch(
             table="presence_stream",
@@ -165,7 +173,7 @@ class PresenceStore(SQLBaseStore):
         for row in rows:
             row["currently_active"] = bool(row["currently_active"])
 
-        defer.returnValue([UserPresenceState(**row) for row in rows])
+        defer.returnValue({row["user_id"]: UserPresenceState(**row) for row in rows})
 
     def get_current_presence_token(self):
         return self._presence_id_gen.get_current_token()
diff --git a/synapse/storage/receipts.py b/synapse/storage/receipts.py
index f72d15f5ed..5cf41501ea 100644
--- a/synapse/storage/receipts.py
+++ b/synapse/storage/receipts.py
@@ -351,6 +351,7 @@ class ReceiptsStore(SQLBaseStore):
                 room_id=room_id,
                 user_id=user_id,
                 topological_ordering=topological_ordering,
+                stream_ordering=stream_ordering,
             )
 
         return True
diff --git a/synapse/storage/schema/delta/40/event_push_summary.sql b/synapse/storage/schema/delta/40/event_push_summary.sql
new file mode 100644
index 0000000000..3918f0b794
--- /dev/null
+++ b/synapse/storage/schema/delta/40/event_push_summary.sql
@@ -0,0 +1,37 @@
+/* Copyright 2017 OpenMarket 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.
+ */
+
+-- Aggregate of old notification counts that have been deleted out of the
+-- main event_push_actions table. This count does not include those that were
+-- highlights, as they remain in the event_push_actions table.
+CREATE TABLE event_push_summary (
+    user_id TEXT NOT NULL,
+    room_id TEXT NOT NULL,
+    notif_count BIGINT NOT NULL,
+    stream_ordering BIGINT NOT NULL
+);
+
+CREATE INDEX event_push_summary_user_rm ON event_push_summary(user_id, room_id);
+
+
+-- The stream ordering up to which we have aggregated the event_push_actions
+-- table into event_push_summary
+CREATE TABLE event_push_summary_stream_ordering (
+    Lock CHAR(1) NOT NULL DEFAULT 'X' UNIQUE,  -- Makes sure this table only has one row.
+    stream_ordering BIGINT NOT NULL,
+    CHECK (Lock='X')
+);
+
+INSERT INTO event_push_summary_stream_ordering (stream_ordering) VALUES (0);
diff --git a/synapse/storage/schema/delta/40/pushers.sql b/synapse/storage/schema/delta/40/pushers.sql
new file mode 100644
index 0000000000..054a223f14
--- /dev/null
+++ b/synapse/storage/schema/delta/40/pushers.sql
@@ -0,0 +1,39 @@
+/* Copyright 2017 Vector Creations 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.
+ */
+
+CREATE TABLE IF NOT EXISTS pushers2 (
+    id BIGINT PRIMARY KEY,
+    user_name TEXT NOT NULL,
+    access_token BIGINT DEFAULT NULL,
+    profile_tag TEXT NOT NULL,
+    kind TEXT NOT NULL,
+    app_id TEXT NOT NULL,
+    app_display_name TEXT NOT NULL,
+    device_display_name TEXT NOT NULL,
+    pushkey TEXT NOT NULL,
+    ts BIGINT NOT NULL,
+    lang TEXT,
+    data TEXT,
+    last_stream_ordering INTEGER,
+    last_success BIGINT,
+    failing_since BIGINT,
+    UNIQUE (app_id, pushkey, user_name)
+);
+
+INSERT INTO pushers2 SELECT * FROM PUSHERS;
+
+DROP TABLE PUSHERS;
+
+ALTER TABLE pushers2 RENAME TO pushers;
diff --git a/synapse/storage/schema/delta/41/device_list_stream_idx.sql b/synapse/storage/schema/delta/41/device_list_stream_idx.sql
new file mode 100644
index 0000000000..b7bee8b692
--- /dev/null
+++ b/synapse/storage/schema/delta/41/device_list_stream_idx.sql
@@ -0,0 +1,17 @@
+/* Copyright 2017 Vector Creations 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.
+ */
+
+INSERT into background_updates (update_name, progress_json)
+    VALUES ('device_lists_stream_idx', '{}');
diff --git a/synapse/storage/schema/delta/41/device_outbound_index.sql b/synapse/storage/schema/delta/41/device_outbound_index.sql
new file mode 100644
index 0000000000..62f0b9892b
--- /dev/null
+++ b/synapse/storage/schema/delta/41/device_outbound_index.sql
@@ -0,0 +1,16 @@
+/* Copyright 2017 Vector Creations 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.
+ */
+
+CREATE INDEX device_lists_outbound_pokes_stream ON device_lists_outbound_pokes(stream_id);
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 1b3800eb6a..84482d8285 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -413,7 +413,19 @@ class StateStore(SQLBaseStore):
         defer.returnValue({event: event_to_state[event] for event in event_ids})
 
     @defer.inlineCallbacks
-    def get_state_ids_for_events(self, event_ids, types):
+    def get_state_ids_for_events(self, event_ids, types=None):
+        """
+        Get the state dicts corresponding to a list of events
+
+        Args:
+            event_ids(list(str)): events whose state should be returned
+            types(list[(str, str)]|None): List of (type, state_key) tuples
+                which are used to filter the state fetched. May be None, which
+                matches any key
+
+        Returns:
+            A deferred dict from event_id -> (type, state_key) -> state_event
+        """
         event_to_groups = yield self._get_state_group_for_events(
             event_ids,
         )