Make AppserviceHandler stream events from database

This is for two reasons:

1. Suppresses duplicates correctly, as the notifier doesn't do any
   duplicate suppression.
2. Makes it easier to connect the AppserviceHandler to the replication
   stream.

2 files changed, 62 insertions, 0 deletions

diff --git a/synapse/storage/appservice.py b/synapse/storage/appservice.py
index d1ee533fac..f0c88e05cd 100644
--- a/synapse/storage/appservice.py
+++ b/synapse/storage/appservice.py
@@ -352,3 +352,42 @@ class ApplicationServiceTransactionStore(SQLBaseStore):
             return 0
         else:
             return int(last_txn_id[0])  # select 'last_txn' col
+
+    def set_appservice_last_pos(self, pos):
+        def set_appservice_last_pos_txn(txn):
+            txn.execute(
+                "UPDATE appservice_stream_position SET stream_ordering = ?", (pos,)
+            )
+        return self.runInteraction(
+            "set_appservice_last_pos", set_appservice_last_pos_txn
+        )
+
+    @defer.inlineCallbacks
+    def get_new_events_for_appservice(self, current_id, limit):
+        """Get all new evnets"""
+
+        def get_new_events_for_appservice_txn(txn):
+            sql = (
+                "SELECT e.stream_ordering, e.event_id"
+                " FROM events AS e, appservice_stream_position AS a"
+                " WHERE a.stream_ordering < e.stream_ordering AND e.stream_ordering <= ?"
+                " ORDER BY e.stream_ordering ASC"
+                " LIMIT ?"
+            )
+
+            txn.execute(sql, (current_id, limit))
+            rows = txn.fetchall()
+
+            upper_bound = current_id
+            if len(rows) == limit:
+                upper_bound = rows[-1][0]
+
+            return upper_bound, [row[1] for row in rows]
+
+        upper_bound, event_ids = yield self.runInteraction(
+            "get_new_events_for_appservice", get_new_events_for_appservice_txn,
+        )
+
+        events = yield self._get_events(event_ids)
+
+        defer.returnValue((upper_bound, events))
diff --git a/synapse/storage/schema/delta/34/appservice_stream.sql b/synapse/storage/schema/delta/34/appservice_stream.sql
new file mode 100644
index 0000000000..69e16eda0f
--- /dev/null
+++ b/synapse/storage/schema/delta/34/appservice_stream.sql
@@ -0,0 +1,23 @@
+/* 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 TABLE IF NOT EXISTS appservice_stream_position(
+    Lock CHAR(1) NOT NULL DEFAULT 'X' UNIQUE,  -- Makes sure this table only has one row.
+    stream_ordering BIGINT,
+    CHECK (Lock='X')
+);
+
+INSERT INTO appservice_stream_position (stream_ordering)
+    SELECT COALESCE(MAX(stream_ordering), 0) FROM events;