From 65e92eca4912848b03f71b7b7d29727015be31ce Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Tue, 2 Feb 2016 15:19:34 +0000
Subject: [PATCH] Change the way we do public room list fetching

---
 synapse/handlers/room.py                      | 80 ++++++++++++++-----
 synapse/storage/room.py                       |  2 +-
 .../schema/delta/28/public_roms_index.sql     | 16 ++++
 3 files changed, 77 insertions(+), 21 deletions(-)
 create mode 100644 synapse/storage/schema/delta/28/public_roms_index.sql

diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index a71cba8ef..1b3f624c6 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -876,31 +876,71 @@ class RoomListHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def get_public_room_list(self):
-        chunk = yield self.store.get_rooms(is_public=True)
+        room_ids = yield self.store.get_public_room_ids()
 
-        room_members = yield defer.gatherResults(
-            [
-                self.store.get_users_in_room(room["room_id"])
-                for room in chunk
-            ],
-            consumeErrors=True,
-        ).addErrback(unwrapFirstError)
+        @defer.inlineCallbacks
+        def handle_room(room_id):
+            aliases = yield self.store.get_aliases_for_room(room_id)
+            if not aliases:
+                defer.returnValue(None)
 
-        avatar_urls = yield defer.gatherResults(
-            [
-                self.get_room_avatar_url(room["room_id"])
-                for room in chunk
-            ],
-            consumeErrors=True,
-        ).addErrback(unwrapFirstError)
+            state = yield self.state_handler.get_current_state(room_id)
 
-        for i, room in enumerate(chunk):
-            room["num_joined_members"] = len(room_members[i])
-            if avatar_urls[i]:
-                room["avatar_url"] = avatar_urls[i]
+            result = {"aliases": aliases, "room_id": room_id}
+
+            name_event = state.get((EventTypes.Name, ""), None)
+            if name_event:
+                name = name_event.content.get("name", None)
+                if name:
+                    result["name"] = name
+
+            topic_event = state.get((EventTypes.Topic, ""), None)
+            if topic_event:
+                topic = topic_event.content.get("topic", None)
+                if topic:
+                    result["topic"] = topic
+
+            canonical_event = state.get((EventTypes.CanonicalAlias, ""), None)
+            if canonical_event:
+                canonical_alias = canonical_event.content.get("alias", None)
+                if canonical_alias:
+                    result["canonical_alias"] = canonical_alias
+
+            visibility_event = state.get((EventTypes.RoomHistoryVisibility, ""), None)
+            visibility = None
+            if visibility_event:
+                visibility = visibility_event.content.get("history_visibility", None)
+            result["world_readable"] = visibility == "world_readable"
+
+            guest_event = state.get((EventTypes.GuestAccess, ""), None)
+            guest = None
+            if guest_event:
+                guest = guest_event.content.get("guest_access", None)
+            result["guest_can_join"] = guest == "can_join"
+
+            avatar_event = state.get(("m.room.avatar", ""), None)
+            if avatar_event:
+                avatar_url = avatar_event.content.get("url", None)
+                if avatar_url:
+                    result["avatar_url"] = avatar_url
+
+            result["num_joined_members"] = sum(
+                1 for (event_type, _), ev in state.items()
+                if event_type == EventTypes.Member and ev.membership == Membership.JOIN
+            )
+
+            defer.returnValue(result)
+
+        result = []
+        for chunk in (room_ids[i:i+10] for i in xrange(0, len(room_ids), 10)):
+            chunk_result = yield defer.gatherResults([
+                handle_room(room_id)
+                for room_id in chunk
+            ], consumeErrors=True).addErrback(unwrapFirstError)
+            result.extend(v for v in chunk_result if v)
 
         # FIXME (erikj): START is no longer a valid value
-        defer.returnValue({"start": "START", "end": "END", "chunk": chunk})
+        defer.returnValue({"start": "START", "end": "END", "chunk": result})
 
     @defer.inlineCallbacks
     def get_room_avatar_url(self, room_id):
diff --git a/synapse/storage/room.py b/synapse/storage/room.py
index dc09a3aab..1b6311f33 100644
--- a/synapse/storage/room.py
+++ b/synapse/storage/room.py
@@ -18,7 +18,7 @@ from twisted.internet import defer
 from synapse.api.errors import StoreError
 
 from ._base import SQLBaseStore
-from synapse.util.caches.descriptors import cachedInlineCallbacks
+from synapse.util.caches.descriptors import cachedInlineCallbacks, cached
 from .engines import PostgresEngine, Sqlite3Engine
 
 import collections
diff --git a/synapse/storage/schema/delta/28/public_roms_index.sql b/synapse/storage/schema/delta/28/public_roms_index.sql
new file mode 100644
index 000000000..ba62a974a
--- /dev/null
+++ b/synapse/storage/schema/delta/28/public_roms_index.sql
@@ -0,0 +1,16 @@
+/* Copyright 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.
+ * 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 public_room_index on rooms(is_public);