comments

syncapi/routing/messages.go

@@ -427,6 +427,7 @@ func setToDefault(
 ) (to types.TopologyToken, err error) {
 	if backwardOrdering {
 		// go 1 earlier than the first event so we correctly fetch the earliest event
+		// this is because Database.GetEventsInTopologicalRange is exclusive of the lower-bound.
 		to = types.NewTopologyToken(0, 0)
 	} else {
 		to, err = db.MaxTopologicalPosition(ctx, roomID)

syncapi/storage/sqlite3/output_room_events_table.go

@@ -306,9 +306,6 @@ func (s *outputRoomEventsStatements) InsertEvent(
 	return
 }
 
-// selectRecentEvents returns the most recent events in the given room, up to a maximum of 'limit'.
-// If onlySyncEvents has a value of true, only returns the events that aren't marked as to exclude
-// from sync.
 func (s *outputRoomEventsStatements) SelectRecentEvents(
 	ctx context.Context, txn *sql.Tx,
 	roomID string, fromPos, toPos types.StreamPosition, limit int,
@@ -341,8 +338,6 @@ func (s *outputRoomEventsStatements) SelectRecentEvents(
 	return events, nil
 }
 
-// selectEarlyEvents returns the earliest events in the given room, starting
-// from a given position, up to a maximum of 'limit'.
 func (s *outputRoomEventsStatements) SelectEarlyEvents(
 	ctx context.Context, txn *sql.Tx,
 	roomID string, fromPos, toPos types.StreamPosition, limit int,

syncapi/storage/tables/interface.go

@@ -11,13 +11,15 @@ import (
 
 type AccountData interface {
 	InsertAccountData(ctx context.Context, txn *sql.Tx, userID, roomID, dataType string) (pos types.StreamPosition, err error)
-	SelectAccountDataInRange(ctx context.Context, userID string, oldPos, newPos types.StreamPosition, accountDataEventFilter *gomatrixserverlib.EventFilter) (data map[string][]string, err error)
+	// SelectAccountDataInRange returns a map of room ID to a list of `dataType`. The range is exclusive of `lowPos` and inclusive of `hiPos`.
+	SelectAccountDataInRange(ctx context.Context, userID string, lowPos, hiPos types.StreamPosition, accountDataEventFilter *gomatrixserverlib.EventFilter) (data map[string][]string, err error)
 	SelectMaxAccountDataID(ctx context.Context, txn *sql.Tx) (id int64, err error)
 }
 
 type Invites interface {
 	InsertInviteEvent(ctx context.Context, txn *sql.Tx, inviteEvent gomatrixserverlib.HeaderedEvent) (streamPos types.StreamPosition, err error)
 	DeleteInviteEvent(ctx context.Context, inviteEventID string) error
+	// SelectInviteEventsInRange returns a map of room ID to invite events. The range is exclusive of `startPos` and inclusive of `endPos`.
 	SelectInviteEventsInRange(ctx context.Context, txn *sql.Tx, targetUserID string, startPos, endPos types.StreamPosition) (map[string]gomatrixserverlib.HeaderedEvent, error)
 	SelectMaxInviteID(ctx context.Context, txn *sql.Tx) (id int64, err error)
 }
@@ -26,7 +28,11 @@ type Events interface {
 	SelectStateInRange(ctx context.Context, txn *sql.Tx, oldPos, newPos types.StreamPosition, stateFilter *gomatrixserverlib.StateFilter) (map[string]map[string]bool, map[string]types.StreamEvent, error)
 	SelectMaxEventID(ctx context.Context, txn *sql.Tx) (id int64, err error)
 	InsertEvent(ctx context.Context, txn *sql.Tx, event *gomatrixserverlib.HeaderedEvent, addState, removeState []string, transactionID *api.TransactionID, excludeFromSync bool) (streamPos types.StreamPosition, err error)
+	// SelectRecentEvents returns events between the two stream positions: exclusive of `fromPos` and inclusive of `toPos`.
+	// If onlySyncEvents has a value of true, only returns the events that aren't marked as to exclude from sync.
+	// Returns up to `limit` events.
 	SelectRecentEvents(ctx context.Context, txn *sql.Tx, roomID string, fromPos, toPos types.StreamPosition, limit int, chronologicalOrder bool, onlySyncEvents bool) ([]types.StreamEvent, error)
+	// SelectEarlyEvents returns the earliest events in the given room, exclusive of `fromPos` and inclusive of `toPos`.
 	SelectEarlyEvents(ctx context.Context, txn *sql.Tx, roomID string, fromPos, toPos types.StreamPosition, limit int) ([]types.StreamEvent, error)
 	SelectEvents(ctx context.Context, txn *sql.Tx, eventIDs []string) ([]types.StreamEvent, error)
 }
@@ -38,6 +44,7 @@ type Topology interface {
 	// `pos` is the stream position of this event in the events table, and is used to order events which have the same depth.
 	InsertEventInTopology(ctx context.Context, txn *sql.Tx, event *gomatrixserverlib.HeaderedEvent, pos types.StreamPosition) (err error)
 	// SelectEventIDsInRange selects the IDs of events whose depths are within a given range in a given room's topological order.
+	// Events with `minDepth` are *exclusive*, as is the event which has exactly `minDepth`,`maxStreamPos`.
 	// `maxStreamPos` is only used when events have the same depth as `maxDepth`, which results in events less than `maxStreamPos` being returned.
 	// Returns an empty slice if no events match the given range.
 	SelectEventIDsInRange(ctx context.Context, txn *sql.Tx, roomID string, minDepth, maxDepth, maxStreamPos types.StreamPosition, limit int, chronologicalOrder bool) (eventIDs []string, err error)