Maybe getMembershipsBeforeEventNID and checkServerAllowedToSeeEvent will work now?

roomserver/query/query.go

@@ -94,6 +94,14 @@ type RoomserverQueryAPIDatabase interface {
 	GetRoomVersionForRoom(
 		ctx context.Context, roomNID types.RoomNID,
 	) (state.StateResolutionVersion, error)
+	// Get the room NID for a given event ID.
+	RoomNIDForEventID(
+		ctx context.Context, eventID string,
+	) (types.RoomNID, error)
+	// Get the room NID for a given event NID.
+	RoomNIDForEventNID(
+		ctx context.Context, eventNID types.EventNID,
+	) (types.RoomNID, error)
 }
 
 // RoomserverQueryAPI is an implementation of api.RoomserverQueryAPI
@@ -115,6 +123,7 @@ func (r *RoomserverQueryAPI) QueryLatestEventsAndState(
 	if roomNID == 0 {
 		return nil
 	}
+	response.RoomExists = true
 	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomNID)
 	if err != nil {
 		return err
@@ -123,7 +132,6 @@ func (r *RoomserverQueryAPI) QueryLatestEventsAndState(
 	if err != nil {
 		return err
 	}
-	response.RoomExists = true
 	var currentStateSnapshotNID types.StateSnapshotNID
 	response.LatestEvents, currentStateSnapshotNID, response.Depth, err =
 		r.DB.LatestEventIDs(ctx, roomNID)
@@ -339,11 +347,19 @@ func (r *RoomserverQueryAPI) QueryMembershipsForRoom(
 func (r *RoomserverQueryAPI) getMembershipsBeforeEventNID(
 	ctx context.Context, eventNID types.EventNID, joinedOnly bool,
 ) ([]types.Event, error) {
-	// TODO: get the correct room version
+	roomNID, err := r.DB.RoomNIDForEventNID(ctx, eventNID)
-	roomState, err := state.GetStateResolutionAlgorithm(state.StateResolutionAlgorithmV1, r.DB)
 	if err != nil {
-		return []types.Event{}, err
+		return nil, err
 	}
+	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomNID)
+	if err != nil {
+		return nil, err
+	}
+	roomState, err := state.GetStateResolutionAlgorithm(roomVersion, r.DB)
+	if err != nil {
+		return nil, err
+	}
+
 	events := []types.Event{}
 	// Lookup the event NID
 	eIDs, err := r.DB.EventIDs(ctx, []types.EventNID{eventNID})
@@ -445,8 +461,15 @@ func (r *RoomserverQueryAPI) QueryServerAllowedToSeeEvent(
 func (r *RoomserverQueryAPI) checkServerAllowedToSeeEvent(
 	ctx context.Context, eventID string, serverName gomatrixserverlib.ServerName,
 ) (bool, error) {
-	// TODO: get the correct room version
+	roomNID, err := r.DB.RoomNIDForEventID(ctx, eventID)
-	roomState, err := state.GetStateResolutionAlgorithm(state.StateResolutionAlgorithmV1, r.DB)
+	if err != nil {
+		return false, err
+	}
+	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomNID)
+	if err != nil {
+		return false, err
+	}
+	roomState, err := state.GetStateResolutionAlgorithm(roomVersion, r.DB)
 	if err != nil {
 		return false, err
 	}

roomserver/storage/postgres/events_table.go

@@ -100,6 +100,12 @@ const updateEventSentToOutputSQL = "" +
 const selectEventIDSQL = "" +
 	"SELECT event_id FROM roomserver_events WHERE event_nid = $1"
 
+const selectRoomNIDForEventIDSQL = "" +
+	"SELECT room_nid FROM roomserver_events WHERE event_id = $1"
+
+const selectRoomNIDForEventNIDSQL = "" +
+	"SELECT room_nid FROM roomserver_events WHERE event_nid = $1"
+
 const bulkSelectStateAtEventAndReferenceSQL = "" +
 	"SELECT event_type_nid, event_state_key_nid, event_nid, state_snapshot_nid, event_id, reference_sha256" +
 	" FROM roomserver_events WHERE event_nid = ANY($1)"
@@ -125,6 +131,8 @@ type eventStatements struct {
 	selectEventSentToOutputStmt            *sql.Stmt
 	updateEventSentToOutputStmt            *sql.Stmt
 	selectEventIDStmt                      *sql.Stmt
+	selectRoomNIDForEventIDStmt            *sql.Stmt
+	selectRoomNIDForEventNIDStmt           *sql.Stmt
 	bulkSelectStateAtEventAndReferenceStmt *sql.Stmt
 	bulkSelectEventReferenceStmt           *sql.Stmt
 	bulkSelectEventIDStmt                  *sql.Stmt
@@ -147,6 +155,8 @@ func (s *eventStatements) prepare(db *sql.DB) (err error) {
 		{&s.updateEventSentToOutputStmt, updateEventSentToOutputSQL},
 		{&s.selectEventSentToOutputStmt, selectEventSentToOutputSQL},
 		{&s.selectEventIDStmt, selectEventIDSQL},
+		{&s.selectRoomNIDForEventIDStmt, selectRoomNIDForEventIDSQL},
+		{&s.selectRoomNIDForEventNIDStmt, selectRoomNIDForEventNIDSQL},
 		{&s.bulkSelectStateAtEventAndReferenceStmt, bulkSelectStateAtEventAndReferenceSQL},
 		{&s.bulkSelectEventReferenceStmt, bulkSelectEventReferenceSQL},
 		{&s.bulkSelectEventIDStmt, bulkSelectEventIDSQL},
@@ -294,6 +304,22 @@ func (s *eventStatements) selectEventID(
 	return
 }
 
+func (s *eventStatements) selectRoomNIDForEventID(
+	ctx context.Context, txn *sql.Tx, eventID string,
+) (roomNID types.RoomNID, err error) {
+	stmt := common.TxStmt(txn, s.selectRoomNIDForEventIDStmt)
+	err = stmt.QueryRowContext(ctx, eventID).Scan(&roomNID)
+	return
+}
+
+func (s *eventStatements) selectRoomNIDForEventNID(
+	ctx context.Context, txn *sql.Tx, eventNID types.EventNID,
+) (roomNID types.RoomNID, err error) {
+	stmt := common.TxStmt(txn, s.selectRoomNIDForEventNIDStmt)
+	err = stmt.QueryRowContext(ctx, eventNID).Scan(&roomNID)
+	return
+}
+
 func (s *eventStatements) bulkSelectStateAtEventAndReference(
 	ctx context.Context, txn *sql.Tx, eventNIDs []types.EventNID,
 ) ([]types.StateAtEventAndReference, error) {

roomserver/storage/postgres/storage.go

@@ -21,6 +21,7 @@ import (
 
 	// Import the postgres database driver.
 	_ "github.com/lib/pq"
+	"github.com/matrix-org/dendrite/common"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/roomserver/state"
 	"github.com/matrix-org/dendrite/roomserver/types"
@@ -414,6 +415,26 @@ func (d *Database) RoomNID(ctx context.Context, roomID string) (types.RoomNID, e
 	return roomNID, err
 }
 
+func (d *Database) RoomNIDForEventID(
+	ctx context.Context, eventID string,
+) (out types.RoomNID, err error) {
+	err = common.WithTransaction(d.db, func(txn *sql.Tx) error {
+		out, err = d.statements.selectRoomNIDForEventID(ctx, txn, eventID)
+		return err
+	})
+	return
+}
+
+func (d *Database) RoomNIDForEventNID(
+	ctx context.Context, eventNID types.EventNID,
+) (out types.RoomNID, err error) {
+	err = common.WithTransaction(d.db, func(txn *sql.Tx) error {
+		out, err = d.statements.selectRoomNIDForEventNID(ctx, txn, eventNID)
+		return err
+	})
+	return
+}
+
 // LatestEventIDs implements query.RoomserverQueryAPIDatabase
 func (d *Database) LatestEventIDs(
 	ctx context.Context, roomNID types.RoomNID,

roomserver/storage/sqlite3/events_table.go

@@ -80,6 +80,12 @@ const updateEventSentToOutputSQL = "" +
 const selectEventIDSQL = "" +
 	"SELECT event_id FROM roomserver_events WHERE event_nid = $1"
 
+const selectRoomNIDForEventIDSQL = "" +
+	"SELECT room_nid FROM roomserver_events WHERE event_id = $1"
+
+const selectRoomNIDForEventNIDSQL = "" +
+	"SELECT room_nid FROM roomserver_events WHERE event_nid = $1"
+
 const bulkSelectStateAtEventAndReferenceSQL = "" +
 	"SELECT event_type_nid, event_state_key_nid, event_nid, state_snapshot_nid, event_id, reference_sha256" +
 	" FROM roomserver_events WHERE event_nid IN ($1)"
@@ -107,6 +113,8 @@ type eventStatements struct {
 	selectEventSentToOutputStmt            *sql.Stmt
 	updateEventSentToOutputStmt            *sql.Stmt
 	selectEventIDStmt                      *sql.Stmt
+	selectRoomNIDForEventIDStmt            *sql.Stmt
+	selectRoomNIDForEventNIDStmt           *sql.Stmt
 	bulkSelectStateAtEventAndReferenceStmt *sql.Stmt
 	bulkSelectEventReferenceStmt           *sql.Stmt
 	bulkSelectEventIDStmt                  *sql.Stmt
@@ -131,6 +139,8 @@ func (s *eventStatements) prepare(db *sql.DB) (err error) {
 		{&s.updateEventSentToOutputStmt, updateEventSentToOutputSQL},
 		{&s.selectEventSentToOutputStmt, selectEventSentToOutputSQL},
 		{&s.selectEventIDStmt, selectEventIDSQL},
+		{&s.selectRoomNIDForEventIDStmt, selectRoomNIDForEventIDSQL},
+		{&s.selectRoomNIDForEventNIDStmt, selectRoomNIDForEventNIDSQL},
 		{&s.bulkSelectStateAtEventAndReferenceStmt, bulkSelectStateAtEventAndReferenceSQL},
 		{&s.bulkSelectEventReferenceStmt, bulkSelectEventReferenceSQL},
 		{&s.bulkSelectEventIDStmt, bulkSelectEventIDSQL},
@@ -310,6 +320,22 @@ func (s *eventStatements) selectEventID(
 	return
 }
 
+func (s *eventStatements) selectRoomNIDForEventID(
+	ctx context.Context, txn *sql.Tx, eventID string,
+) (roomNID types.RoomNID, err error) {
+	stmt := common.TxStmt(txn, s.selectRoomNIDForEventIDStmt)
+	err = stmt.QueryRowContext(ctx, eventID).Scan(&roomNID)
+	return
+}
+
+func (s *eventStatements) selectRoomNIDForEventNID(
+	ctx context.Context, txn *sql.Tx, eventNID types.EventNID,
+) (roomNID types.RoomNID, err error) {
+	stmt := common.TxStmt(txn, s.selectRoomNIDForEventNIDStmt)
+	err = stmt.QueryRowContext(ctx, eventNID).Scan(&roomNID)
+	return
+}
+
 func (s *eventStatements) bulkSelectStateAtEventAndReference(
 	ctx context.Context, txn *sql.Tx, eventNIDs []types.EventNID,
 ) ([]types.StateAtEventAndReference, error) {

roomserver/storage/sqlite3/storage.go

@@ -533,6 +533,26 @@ func (d *Database) RoomNID(ctx context.Context, roomID string) (roomNID types.Ro
 	return
 }
 
+func (d *Database) RoomNIDForEventID(
+	ctx context.Context, eventID string,
+) (out types.RoomNID, err error) {
+	err = common.WithTransaction(d.db, func(txn *sql.Tx) error {
+		out, err = d.statements.selectRoomNIDForEventID(ctx, txn, eventID)
+		return err
+	})
+	return
+}
+
+func (d *Database) RoomNIDForEventNID(
+	ctx context.Context, eventNID types.EventNID,
+) (out types.RoomNID, err error) {
+	err = common.WithTransaction(d.db, func(txn *sql.Tx) error {
+		out, err = d.statements.selectRoomNIDForEventNID(ctx, txn, eventNID)
+		return err
+	})
+	return
+}
+
 // LatestEventIDs implements query.RoomserverQueryAPIDatabase
 func (d *Database) LatestEventIDs(
 	ctx context.Context, roomNID types.RoomNID,

roomserver/storage/storage.go

@@ -38,6 +38,8 @@ type Database interface {
 	GetLatestEventsForUpdate(ctx context.Context, roomNID types.RoomNID) (types.RoomRecentEventsUpdater, error)
 	GetTransactionEventID(ctx context.Context, transactionID string, sessionID int64, userID string) (string, error)
 	RoomNID(ctx context.Context, roomID string) (types.RoomNID, error)
+	RoomNIDForEventID(ctx context.Context, eventID string) (types.RoomNID, error)
+	RoomNIDForEventNID(ctx context.Context, eventNID types.EventNID) (types.RoomNID, error)
 	LatestEventIDs(ctx context.Context, roomNID types.RoomNID) ([]gomatrixserverlib.EventReference, types.StateSnapshotNID, int64, error)
 	GetInvitesForUser(ctx context.Context, roomNID types.RoomNID, targetUserNID types.EventStateKeyNID) (senderUserIDs []types.EventStateKeyNID, err error)
 	SetRoomAlias(ctx context.Context, alias string, roomID string, creatorUserID string) error