diff --git a/synapse/storage/databases/main/event_federation.py b/synapse/storage/databases/main/event_federation.py
index ca71f073fc..22f6474127 100644
--- a/synapse/storage/databases/main/event_federation.py
+++ b/synapse/storage/databases/main/event_federation.py
@@ -16,9 +16,10 @@ import logging
from queue import Empty, PriorityQueue
from typing import TYPE_CHECKING, Collection, Dict, Iterable, List, Optional, Set, Tuple
+import attr
from prometheus_client import Counter, Gauge
-from synapse.api.constants import MAX_DEPTH
+from synapse.api.constants import MAX_DEPTH, EventTypes
from synapse.api.errors import StoreError
from synapse.api.room_versions import EventFormatVersions, RoomVersion
from synapse.events import EventBase, make_event_from_dict
@@ -60,6 +61,15 @@ pdus_pruned_from_federation_queue = Counter(
logger = logging.getLogger(__name__)
+# All the info we need while iterating the DAG while backfilling
+@attr.s(frozen=True, slots=True, auto_attribs=True)
+class BackfillQueueNavigationItem:
+ depth: int
+ stream_ordering: int
+ event_id: str
+ type: str
+
+
class _NoChainCoverIndex(Exception):
def __init__(self, room_id: str):
super().__init__("Unexpectedly no chain cover for events in %s" % (room_id,))
@@ -74,6 +84,8 @@ class EventFederationWorkerStore(SignatureWorkerStore, EventsWorkerStore, SQLBas
):
super().__init__(database, db_conn, hs)
+ self.hs = hs
+
if hs.config.worker.run_background_tasks:
hs.get_clock().looping_call(
self._delete_old_forward_extrem_cache, 60 * 60 * 1000
@@ -737,7 +749,7 @@ class EventFederationWorkerStore(SignatureWorkerStore, EventsWorkerStore, SQLBas
room_id,
)
- async def get_insertion_event_backwards_extremities_in_room(
+ async def get_insertion_event_backward_extremities_in_room(
self, room_id
) -> Dict[str, int]:
"""Get the insertion events we know about that we haven't backfilled yet.
@@ -754,7 +766,7 @@ class EventFederationWorkerStore(SignatureWorkerStore, EventsWorkerStore, SQLBas
Map from event_id to depth
"""
- def get_insertion_event_backwards_extremities_in_room_txn(txn, room_id):
+ def get_insertion_event_backward_extremities_in_room_txn(txn, room_id):
sql = """
SELECT b.event_id, MAX(e.depth) FROM insertion_events as i
/* We only want insertion events that are also marked as backwards extremities */
@@ -770,8 +782,8 @@ class EventFederationWorkerStore(SignatureWorkerStore, EventsWorkerStore, SQLBas
return dict(txn)
return await self.db_pool.runInteraction(
- "get_insertion_event_backwards_extremities_in_room",
- get_insertion_event_backwards_extremities_in_room_txn,
+ "get_insertion_event_backward_extremities_in_room",
+ get_insertion_event_backward_extremities_in_room_txn,
room_id,
)
@@ -997,143 +1009,242 @@ class EventFederationWorkerStore(SignatureWorkerStore, EventsWorkerStore, SQLBas
"get_forward_extremeties_for_room", get_forward_extremeties_for_room_txn
)
- async def get_backfill_events(self, room_id: str, event_list: list, limit: int):
- """Get a list of Events for a given topic that occurred before (and
- including) the events in event_list. Return a list of max size `limit`
+ def _get_connected_batch_event_backfill_results_txn(
+ self, txn: LoggingTransaction, insertion_event_id: str, limit: int
+ ) -> List[BackfillQueueNavigationItem]:
+ """
+ Find any batch connections of a given insertion event.
+ A batch event points at a insertion event via:
+ batch_event.content[MSC2716_BATCH_ID] -> insertion_event.content[MSC2716_NEXT_BATCH_ID]
Args:
- room_id
- event_list
- limit
+ txn: The database transaction to use
+ insertion_event_id: The event ID to navigate from. We will find
+ batch events that point back at this insertion event.
+ limit: Max number of event ID's to query for and return
+
+ Returns:
+ List of batch events that the backfill queue can process
+ """
+ batch_connection_query = """
+ SELECT e.depth, e.stream_ordering, c.event_id, e.type FROM insertion_events AS i
+ /* Find the batch that connects to the given insertion event */
+ INNER JOIN batch_events AS c
+ ON i.next_batch_id = c.batch_id
+ /* Get the depth of the batch start event from the events table */
+ INNER JOIN events AS e USING (event_id)
+ /* Find an insertion event which matches the given event_id */
+ WHERE i.event_id = ?
+ LIMIT ?
"""
- event_ids = await self.db_pool.runInteraction(
- "get_backfill_events",
- self._get_backfill_events,
- room_id,
- event_list,
- limit,
- )
- events = await self.get_events_as_list(event_ids)
- return sorted(events, key=lambda e: -e.depth)
- def _get_backfill_events(self, txn, room_id, event_list, limit):
- logger.debug("_get_backfill_events: %s, %r, %s", room_id, event_list, limit)
+ # Find any batch connections for the given insertion event
+ txn.execute(
+ batch_connection_query,
+ (insertion_event_id, limit),
+ )
+ return [
+ BackfillQueueNavigationItem(
+ depth=row[0],
+ stream_ordering=row[1],
+ event_id=row[2],
+ type=row[3],
+ )
+ for row in txn
+ ]
- event_results = set()
+ def _get_connected_prev_event_backfill_results_txn(
+ self, txn: LoggingTransaction, event_id: str, limit: int
+ ) -> List[BackfillQueueNavigationItem]:
+ """
+ Find any events connected by prev_event the specified event_id.
- # We want to make sure that we do a breadth-first, "depth" ordered
- # search.
+ Args:
+ txn: The database transaction to use
+ event_id: The event ID to navigate from
+ limit: Max number of event ID's to query for and return
+ Returns:
+ List of prev events that the backfill queue can process
+ """
# Look for the prev_event_id connected to the given event_id
- query = """
- SELECT depth, prev_event_id FROM event_edges
- /* Get the depth of the prev_event_id from the events table */
+ connected_prev_event_query = """
+ SELECT depth, stream_ordering, prev_event_id, events.type FROM event_edges
+ /* Get the depth and stream_ordering of the prev_event_id from the events table */
INNER JOIN events
ON prev_event_id = events.event_id
- /* Find an event which matches the given event_id */
+ /* Look for an edge which matches the given event_id */
WHERE event_edges.event_id = ?
AND event_edges.is_state = ?
+ /* Because we can have many events at the same depth,
+ * we want to also tie-break and sort on stream_ordering */
+ ORDER BY depth DESC, stream_ordering DESC
LIMIT ?
"""
- # Look for the "insertion" events connected to the given event_id
- connected_insertion_event_query = """
- SELECT e.depth, i.event_id FROM insertion_event_edges AS i
- /* Get the depth of the insertion event from the events table */
- INNER JOIN events AS e USING (event_id)
- /* Find an insertion event which points via prev_events to the given event_id */
- WHERE i.insertion_prev_event_id = ?
- LIMIT ?
+ txn.execute(
+ connected_prev_event_query,
+ (event_id, False, limit),
+ )
+ return [
+ BackfillQueueNavigationItem(
+ depth=row[0],
+ stream_ordering=row[1],
+ event_id=row[2],
+ type=row[3],
+ )
+ for row in txn
+ ]
+
+ async def get_backfill_events(
+ self, room_id: str, seed_event_id_list: list, limit: int
+ ):
+ """Get a list of Events for a given topic that occurred before (and
+ including) the events in seed_event_id_list. Return a list of max size `limit`
+
+ Args:
+ room_id
+ seed_event_id_list
+ limit
"""
+ event_ids = await self.db_pool.runInteraction(
+ "get_backfill_events",
+ self._get_backfill_events,
+ room_id,
+ seed_event_id_list,
+ limit,
+ )
+ events = await self.get_events_as_list(event_ids)
+ return sorted(
+ events, key=lambda e: (-e.depth, -e.internal_metadata.stream_ordering)
+ )
- # Find any batch connections of a given insertion event
- batch_connection_query = """
- SELECT e.depth, c.event_id FROM insertion_events AS i
- /* Find the batch that connects to the given insertion event */
- INNER JOIN batch_events AS c
- ON i.next_batch_id = c.batch_id
- /* Get the depth of the batch start event from the events table */
- INNER JOIN events AS e USING (event_id)
- /* Find an insertion event which matches the given event_id */
- WHERE i.event_id = ?
- LIMIT ?
+ def _get_backfill_events(self, txn, room_id, seed_event_id_list, limit):
+ """
+ We want to make sure that we do a breadth-first, "depth" ordered search.
+ We also handle navigating historical branches of history connected by
+ insertion and batch events.
"""
+ logger.debug(
+ "_get_backfill_events(room_id=%s): seeding backfill with seed_event_id_list=%s limit=%s",
+ room_id,
+ seed_event_id_list,
+ limit,
+ )
+
+ event_id_results = set()
# In a PriorityQueue, the lowest valued entries are retrieved first.
- # We're using depth as the priority in the queue.
- # Depth is lowest at the oldest-in-time message and highest and
- # newest-in-time message. We add events to the queue with a negative depth so that
- # we process the newest-in-time messages first going backwards in time.
+ # We're using depth as the priority in the queue and tie-break based on
+ # stream_ordering. Depth is lowest at the oldest-in-time message and
+ # highest and newest-in-time message. We add events to the queue with a
+ # negative depth so that we process the newest-in-time messages first
+ # going backwards in time. stream_ordering follows the same pattern.
queue = PriorityQueue()
- for event_id in event_list:
- depth = self.db_pool.simple_select_one_onecol_txn(
+ for seed_event_id in seed_event_id_list:
+ event_lookup_result = self.db_pool.simple_select_one_txn(
txn,
table="events",
- keyvalues={"event_id": event_id, "room_id": room_id},
- retcol="depth",
+ keyvalues={"event_id": seed_event_id, "room_id": room_id},
+ retcols=(
+ "type",
+ "depth",
+ "stream_ordering",
+ ),
allow_none=True,
)
- if depth:
- queue.put((-depth, event_id))
+ if event_lookup_result is not None:
+ logger.debug(
+ "_get_backfill_events(room_id=%s): seed_event_id=%s depth=%s stream_ordering=%s type=%s",
+ room_id,
+ seed_event_id,
+ event_lookup_result["depth"],
+ event_lookup_result["stream_ordering"],
+ event_lookup_result["type"],
+ )
- while not queue.empty() and len(event_results) < limit:
+ if event_lookup_result["depth"]:
+ queue.put(
+ (
+ -event_lookup_result["depth"],
+ -event_lookup_result["stream_ordering"],
+ seed_event_id,
+ event_lookup_result["type"],
+ )
+ )
+
+ while not queue.empty() and len(event_id_results) < limit:
try:
- _, event_id = queue.get_nowait()
+ _, _, event_id, event_type = queue.get_nowait()
except Empty:
break
- if event_id in event_results:
+ if event_id in event_id_results:
continue
- event_results.add(event_id)
+ event_id_results.add(event_id)
# Try and find any potential historical batches of message history.
- #
- # First we look for an insertion event connected to the current
- # event (by prev_event). If we find any, we need to go and try to
- # find any batch events connected to the insertion event (by
- # batch_id). If we find any, we'll add them to the queue and
- # navigate up the DAG like normal in the next iteration of the loop.
- txn.execute(
- connected_insertion_event_query, (event_id, limit - len(event_results))
- )
- connected_insertion_event_id_results = txn.fetchall()
- logger.debug(
- "_get_backfill_events: connected_insertion_event_query %s",
- connected_insertion_event_id_results,
- )
- for row in connected_insertion_event_id_results:
- connected_insertion_event_depth = row[0]
- connected_insertion_event = row[1]
- queue.put((-connected_insertion_event_depth, connected_insertion_event))
+ if self.hs.config.experimental.msc2716_enabled:
+ # We need to go and try to find any batch events connected
+ # to a given insertion event (by batch_id). If we find any, we'll
+ # add them to the queue and navigate up the DAG like normal in the
+ # next iteration of the loop.
+ if event_type == EventTypes.MSC2716_INSERTION:
+ # Find any batch connections for the given insertion event
+ connected_batch_event_backfill_results = (
+ self._get_connected_batch_event_backfill_results_txn(
+ txn, event_id, limit - len(event_id_results)
+ )
+ )
+ logger.debug(
+ "_get_backfill_events(room_id=%s): connected_batch_event_backfill_results=%s",
+ room_id,
+ connected_batch_event_backfill_results,
+ )
+ for (
+ connected_batch_event_backfill_item
+ ) in connected_batch_event_backfill_results:
+ if (
+ connected_batch_event_backfill_item.event_id
+ not in event_id_results
+ ):
+ queue.put(
+ (
+ -connected_batch_event_backfill_item.depth,
+ -connected_batch_event_backfill_item.stream_ordering,
+ connected_batch_event_backfill_item.event_id,
+ connected_batch_event_backfill_item.type,
+ )
+ )
- # Find any batch connections for the given insertion event
- txn.execute(
- batch_connection_query,
- (connected_insertion_event, limit - len(event_results)),
- )
- batch_start_event_id_results = txn.fetchall()
- logger.debug(
- "_get_backfill_events: batch_start_event_id_results %s",
- batch_start_event_id_results,
+ # Now we just look up the DAG by prev_events as normal
+ connected_prev_event_backfill_results = (
+ self._get_connected_prev_event_backfill_results_txn(
+ txn, event_id, limit - len(event_id_results)
)
- for row in batch_start_event_id_results:
- if row[1] not in event_results:
- queue.put((-row[0], row[1]))
-
- txn.execute(query, (event_id, False, limit - len(event_results)))
- prev_event_id_results = txn.fetchall()
+ )
logger.debug(
- "_get_backfill_events: prev_event_ids %s", prev_event_id_results
+ "_get_backfill_events(room_id=%s): connected_prev_event_backfill_results=%s",
+ room_id,
+ connected_prev_event_backfill_results,
)
+ for (
+ connected_prev_event_backfill_item
+ ) in connected_prev_event_backfill_results:
+ if connected_prev_event_backfill_item.event_id not in event_id_results:
+ queue.put(
+ (
+ -connected_prev_event_backfill_item.depth,
+ -connected_prev_event_backfill_item.stream_ordering,
+ connected_prev_event_backfill_item.event_id,
+ connected_prev_event_backfill_item.type,
+ )
+ )
- for row in prev_event_id_results:
- if row[1] not in event_results:
- queue.put((-row[0], row[1]))
-
- return event_results
+ return event_id_results
async def get_missing_events(self, room_id, earliest_events, latest_events, limit):
ids = await self.db_pool.runInteraction(
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index b7554154ac..b804185c40 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -2215,9 +2215,14 @@ class PersistEventsStore:
" SELECT 1 FROM event_backward_extremities"
" WHERE event_id = ? AND room_id = ?"
" )"
+ # 1. Don't add an event as a extremity again if we already persisted it
+ # as a non-outlier.
+ # 2. Don't add an outlier as an extremity if it has no prev_events
" AND NOT EXISTS ("
- " SELECT 1 FROM events WHERE event_id = ? AND room_id = ? "
- " AND outlier = ?"
+ " SELECT 1 FROM events"
+ " LEFT JOIN event_edges edge"
+ " ON edge.event_id = events.event_id"
+ " WHERE events.event_id = ? AND events.room_id = ? AND (events.outlier = ? OR edge.event_id IS NULL)"
" )"
)
@@ -2243,6 +2248,10 @@ class PersistEventsStore:
(ev.event_id, ev.room_id)
for ev in events
if not ev.internal_metadata.is_outlier()
+ # If we encountered an event with no prev_events, then we might
+ # as well remove it now because it won't ever have anything else
+ # to backfill from.
+ or len(ev.prev_event_ids()) == 0
],
)
|
