From 3ae915b27e4531031ee325931b3c62bc200ce798 Mon Sep 17 00:00:00 2001
From: Mark Haines <mjark@negativecurvature.net>
Date: Fri, 3 Jun 2016 11:05:53 +0100
Subject: [PATCH] Add a slaved store for presence

---
 synapse/replication/slave/storage/presence.py | 59 +++++++++++++++++++
 synapse/storage/__init__.py                   |  6 +-
 2 files changed, 62 insertions(+), 3 deletions(-)
 create mode 100644 synapse/replication/slave/storage/presence.py

diff --git a/synapse/replication/slave/storage/presence.py b/synapse/replication/slave/storage/presence.py
new file mode 100644
index 0000000000..703f4a49bf
--- /dev/null
+++ b/synapse/replication/slave/storage/presence.py
@@ -0,0 +1,59 @@
+# -*- coding: utf-8 -*-
+# 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.
+
+from ._base import BaseSlavedStore
+from ._slaved_id_tracker import SlavedIdTracker
+
+from synapse.util.caches.stream_change_cache import StreamChangeCache
+from synapse.storage import DataStore
+
+
+class SlavedPresenceStore(BaseSlavedStore):
+    def __init__(self, db_conn, hs):
+        super(SlavedPresenceStore, self).__init__(db_conn, hs)
+        self._presence_id_gen = SlavedIdTracker(
+            db_conn, "presence_stream", "stream_id",
+        )
+
+        self._presence_on_startup = self._get_active_presence(db_conn)
+
+        self.presence_stream_cache = self.presence_stream_cache = StreamChangeCache(
+            "PresenceStreamChangeCache", self._presence_id_gen.get_current_token()
+        )
+
+    _get_active_presence = DataStore._get_active_presence.__func__
+    take_presence_startup_info = DataStore.take_presence_startup_info.__func__
+    get_presence_for_users = DataStore.get_presence_for_users.__func__
+
+    def get_current_presence_token(self):
+        return self._presence_id_gen.get_current_token()
+
+    def stream_positions(self):
+        result = super(SlavedPresenceStore, self).stream_positions()
+        position = self._presence_id_gen.get_current_token()
+        result["presence"] = position
+        return result
+
+    def process_replication(self, result):
+        stream = result.get("presence")
+        if stream:
+            self._presence_id_gen.advance(int(stream["position"]))
+            for row in stream["rows"]:
+                position, user_id = row[:2]
+                self.presence_stream_cache.entity_has_changed(
+                    user_id, position
+                )
+
+        return super(SlavedPresenceStore, self).process_replication(result)
diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index 8581796b7e..6928a213e8 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -149,7 +149,7 @@ class DataStore(RoomMemberStore, RoomStore,
             "AccountDataAndTagsChangeCache", account_max,
         )
 
-        self.__presence_on_startup = self._get_active_presence(db_conn)
+        self._presence_on_startup = self._get_active_presence(db_conn)
 
         presence_cache_prefill, min_presence_val = self._get_cache_dict(
             db_conn, "presence_stream",
@@ -190,8 +190,8 @@ class DataStore(RoomMemberStore, RoomStore,
         super(DataStore, self).__init__(hs)
 
     def take_presence_startup_info(self):
-        active_on_startup = self.__presence_on_startup
-        self.__presence_on_startup = None
+        active_on_startup = self._presence_on_startup
+        self._presence_on_startup = None
         return active_on_startup
 
     def _get_active_presence(self, db_conn):