From 8b0dfc9fc4e98ea9c029c5f7b49efaf011ce1979 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 23 Mar 2016 11:37:58 +0000
Subject: [PATCH] Don't cache events in get_current_state_for_key

---
 synapse/storage/events.py |  4 ++--
 synapse/storage/state.py  | 16 +++++++++-------
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index e444b64cee..7bcddf1f31 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -157,7 +157,7 @@ class EventsStore(SQLBaseStore):
         # We purposefully do this first since if we include a `current_state`
         # key, we *want* to update the `current_state_events` table
         if current_state:
-            txn.call_after(self.get_current_state_for_key.invalidate_all)
+            txn.call_after(self._get_current_state_for_key.invalidate_all)
             txn.call_after(self.get_rooms_for_user.invalidate_all)
             txn.call_after(self.get_users_in_room.invalidate, (event.room_id,))
             txn.call_after(self.get_joined_hosts_for_room.invalidate, (event.room_id,))
@@ -441,7 +441,7 @@ class EventsStore(SQLBaseStore):
             for event, _ in state_events_and_contexts:
                 if not context.rejected:
                     txn.call_after(
-                        self.get_current_state_for_key.invalidate,
+                        self._get_current_state_for_key.invalidate,
                         (event.room_id, event.type, event.state_key,)
                     )
 
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index f06c734c4e..eab2c5a8ce 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -14,9 +14,7 @@
 # limitations under the License.
 
 from ._base import SQLBaseStore
-from synapse.util.caches.descriptors import (
-    cached, cachedInlineCallbacks, cachedList
-)
+from synapse.util.caches.descriptors import cached, cachedList
 
 from twisted.internet import defer
 
@@ -155,8 +153,14 @@ class StateStore(SQLBaseStore):
         events = yield self._get_events(event_ids, get_prev_content=False)
         defer.returnValue(events)
 
-    @cachedInlineCallbacks(num_args=3)
+    @defer.inlineCallbacks
     def get_current_state_for_key(self, room_id, event_type, state_key):
+        event_ids = yield self._get_current_state_for_key(room_id, event_type, state_key)
+        events = yield self._get_events(event_ids, get_prev_content=False)
+        defer.returnValue(events)
+
+    @cached(num_args=3)
+    def _get_current_state_for_key(self, room_id, event_type, state_key):
         def f(txn):
             sql = (
                 "SELECT event_id FROM current_state_events"
@@ -167,9 +171,7 @@ class StateStore(SQLBaseStore):
             txn.execute(sql, args)
             results = txn.fetchall()
             return [r[0] for r in results]
-        event_ids = yield self.runInteraction("get_current_state_for_key", f)
-        events = yield self._get_events(event_ids, get_prev_content=False)
-        defer.returnValue(events)
+        return self.runInteraction("get_current_state_for_key", f)
 
     def _get_state_groups_from_groups(self, groups, types):
         """Returns dictionary state_group -> (dict of (type, state_key) -> event id)