From 10523241d86eeaa1fa43607a03352f9e7b04efda Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 18 Jul 2019 15:17:37 +0100
Subject: [PATCH 1/2] Delegate to cached version when using
 get_filtered_current_state_ids

In the case where it gets called with `StateFilter.all()`
---
 synapse/storage/state.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 0bfe1b455..a35289876 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -510,6 +510,12 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
             event ID.
         """
 
+        where_clause, where_args = state_filter.make_sql_filter_clause()
+
+        if not where_clause:
+            # We delegate to the cached version
+            return self.get_current_state_ids(room_id)
+
         def _get_filtered_current_state_ids_txn(txn):
             results = {}
             sql = """
@@ -517,8 +523,6 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
                 WHERE room_id = ?
             """
 
-            where_clause, where_args = state_filter.make_sql_filter_clause()
-
             if where_clause:
                 sql += " AND (%s)" % (where_clause,)
 

From dd2851d576649194205725bb5105f3cbb4a87e55 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 18 Jul 2019 15:27:18 +0100
Subject: [PATCH 2/2] Newsfile

---
 changelog.d/5713.misc | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/5713.misc

diff --git a/changelog.d/5713.misc b/changelog.d/5713.misc
new file mode 100644
index 000000000..01ea1cf8d
--- /dev/null
+++ b/changelog.d/5713.misc
@@ -0,0 +1 @@
+Improve caching when fetching `get_filtered_current_state_ids`.