diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index cad103d39f..9b1d4d9594 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -188,8 +188,14 @@ class FederationHandler:
),
key=lambda e: -int(e[1]),
)
-
- max_depth = sorted_extremeties_tuples[0][1]
+ logger.debug(
+ "_maybe_backfill_inner: room_id: %s: current_depth: %s, limit: %s, extrems (%d): %s",
+ room_id,
+ current_depth,
+ limit,
+ len(sorted_extremeties_tuples),
+ sorted_extremeties_tuples,
+ )
# If we're approaching an extremity we trigger a backfill, otherwise we
# no-op.
@@ -200,6 +206,11 @@ class FederationHandler:
# chose more than one times the limit in case of failure, but choosing a
# much larger factor will result in triggering a backfill request much
# earlier than necessary.
+ #
+ # XXX: shouldn't we do this *after* the filter by depth below? Again, we don't
+ # care about events that have happened after our current position.
+ #
+ max_depth = sorted_extremeties_tuples[0][1]
if current_depth - 2 * limit > max_depth:
logger.debug(
"Not backfilling as we don't need to. %d < %d - 2 * %d",
@@ -216,27 +227,25 @@ class FederationHandler:
# 2. we have likely previously tried and failed to backfill from that
# extremity, so to avoid getting "stuck" requesting the same
# backfill repeatedly we drop those extremities.
- filtered_sorted_extremeties_tuples = [
- t for t in sorted_extremeties_tuples if int(t[1]) <= current_depth
- ]
-
- logger.debug(
- "room_id: %s, backfill: current_depth: %s, limit: %s, max_depth: %s, extrems (%d): %s filtered_sorted_extremeties_tuples: %s",
- room_id,
- current_depth,
- limit,
- max_depth,
- len(sorted_extremeties_tuples),
- sorted_extremeties_tuples,
- filtered_sorted_extremeties_tuples,
- )
-
+ #
# However, we need to check that the filtered extremities are non-empty.
# If they are empty then either we can a) bail or b) still attempt to
# backfill. We opt to try backfilling anyway just in case we do get
# relevant events.
+ #
+ filtered_sorted_extremeties_tuples = [
+ t for t in sorted_extremeties_tuples if int(t[1]) <= current_depth
+ ]
if filtered_sorted_extremeties_tuples:
+ logger.debug(
+ "_maybe_backfill_inner: extrems before current depth: %s",
+ filtered_sorted_extremeties_tuples,
+ )
sorted_extremeties_tuples = filtered_sorted_extremeties_tuples
+ else:
+ logger.debug(
+ "_maybe_backfill_inner: all extrems are *after* current depth. Backfilling anyway."
+ )
# We only want to paginate if we can actually see the events we'll get,
# as otherwise we'll just spend a lot of resources to get redacted
|
