Merge pull request #489 from matrix-org/markjh/replication

Add a /replication API for extracting the updates that happened on synapse.

1 files changed, 45 insertions, 0 deletions

diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 73a152bc07..60936500d8 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -1064,3 +1064,48 @@ class EventsStore(SQLBaseStore):
             yield self._end_background_update(self.EVENT_ORIGIN_SERVER_TS_NAME)
 
         defer.returnValue(result)
+
+    def get_current_backfill_token(self):
+        """The current minimum token that backfilled events have reached"""
+
+        # TODO: Fix race with the persit_event txn by using one of the
+        # stream id managers
+        return -self.min_stream_token
+
+    def get_all_new_events(self, last_backfill_id, last_forward_id,
+                           current_backfill_id, current_forward_id, limit):
+        """Get all the new events that have arrived at the server either as
+        new events or as backfilled events"""
+        def get_all_new_events_txn(txn):
+            sql = (
+                "SELECT e.stream_ordering, ej.internal_metadata, ej.json"
+                " FROM events as e"
+                " JOIN event_json as ej"
+                " ON e.event_id = ej.event_id AND e.room_id = ej.room_id"
+                " WHERE ? < e.stream_ordering AND e.stream_ordering <= ?"
+                " ORDER BY e.stream_ordering ASC"
+                " LIMIT ?"
+            )
+            if last_forward_id != current_forward_id:
+                txn.execute(sql, (last_forward_id, current_forward_id, limit))
+                new_forward_events = txn.fetchall()
+            else:
+                new_forward_events = []
+
+            sql = (
+                "SELECT -e.stream_ordering, ej.internal_metadata, ej.json"
+                " FROM events as e"
+                " JOIN event_json as ej"
+                " ON e.event_id = ej.event_id AND e.room_id = ej.room_id"
+                " WHERE ? > e.stream_ordering AND e.stream_ordering >= ?"
+                " ORDER BY e.stream_ordering DESC"
+                " LIMIT ?"
+            )
+            if last_backfill_id != current_backfill_id:
+                txn.execute(sql, (-last_backfill_id, -current_backfill_id, limit))
+                new_backfill_events = txn.fetchall()
+            else:
+                new_backfill_events = []
+
+            return (new_forward_events, new_backfill_events)
+        return self.runInteraction("get_all_new_events", get_all_new_events_txn)