From db3400d0a7dc93f5018aba5c5e54fe35bb392e81 Mon Sep 17 00:00:00 2001
From: Mark Haines <mjark@negativecurvature.net>
Date: Mon, 5 Jun 2017 16:54:15 +0100
Subject: [PATCH] Comments
---
.../dendrite/syncapi/consumers/roomserver.go | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/src/github.com/matrix-org/dendrite/syncapi/consumers/roomserver.go b/src/github.com/matrix-org/dendrite/syncapi/consumers/roomserver.go
index d8ba4e567..b8604ea95 100644
--- a/src/github.com/matrix-org/dendrite/syncapi/consumers/roomserver.go
+++ b/src/github.com/matrix-org/dendrite/syncapi/consumers/roomserver.go
@@ -116,23 +116,30 @@ func (s *OutputRoomEvent) onMessage(msg *sarama.ConsumerMessage) error {
return nil
}
+// addsStateEvents looks up the state events that are added by a new event.
func (s *OutputRoomEvent) addsStateEvents(
addsStateEventIDs []string, event gomatrixserverlib.Event,
) ([]gomatrixserverlib.Event, error) {
+ // Fast path if there aren't any new state events.
if len(addsStateEventIDs) == 0 {
return nil, nil
}
+ // Fast path if the only state event added is the event itself.
if len(addsStateEventIDs) == 1 && addsStateEventIDs[0] == event.EventID() {
return []gomatrixserverlib.Event{event}, nil
}
+ // Check if this is re-adding a state events that we previously processed
+ // If we have previously received a state event it may still be in
+ // our event database.
result, err := s.db.Events(addsStateEventIDs)
if err != nil {
return nil, err
}
missing := missingEventsFrom(result, addsStateEventIDs)
+ // Check if event itself is being added.
for _, eventID := range missing {
if eventID == event.EventID() {
result = append(result, event)
@@ -145,6 +152,9 @@ func (s *OutputRoomEvent) addsStateEvents(
return result, nil
}
+ // At this point the missing events are neither the event itself nor are
+ // they present in our local database. Our only option is to fetch them
+ // from the roomserver using the query API.
eventReq := api.QueryEventsByIDRequest{EventIDs: missing}
var eventResp api.QueryEventsByIDResponse
if err := s.query.QueryEventsByID(&eventReq, &eventResp); err != nil {