Add RoomInfo struct

roomserver/internal/query.go

@@ -46,11 +46,11 @@ func (r *RoomserverInternalAPI) QueryLatestEventsAndState(
 
 	roomState := state.NewStateResolution(r.DB)
 
-	roomNID, err := r.DB.RoomNIDExcludingStubs(ctx, request.RoomID)
+	info, err := r.DB.RoomInfo(ctx, request.RoomID)
 	if err != nil {
 		return err
 	}
-	if roomNID == 0 {
+	if info.IsStub {
 		return nil
 	}
 	response.RoomExists = true
@@ -58,7 +58,7 @@ func (r *RoomserverInternalAPI) QueryLatestEventsAndState(
 
 	var currentStateSnapshotNID types.StateSnapshotNID
 	response.LatestEvents, currentStateSnapshotNID, response.Depth, err =
-		r.DB.LatestEventIDs(ctx, roomNID)
+		r.DB.LatestEventIDs(ctx, info.RoomNID)
 	if err != nil {
 		return err
 	}
@@ -105,11 +105,11 @@ func (r *RoomserverInternalAPI) QueryStateAfterEvents(
 
 	roomState := state.NewStateResolution(r.DB)
 
-	roomNID, err := r.DB.RoomNIDExcludingStubs(ctx, request.RoomID)
+	info, err := r.DB.RoomInfo(ctx, request.RoomID)
 	if err != nil {
 		return err
 	}
-	if roomNID == 0 {
+	if info.IsStub {
 		return nil
 	}
 	response.RoomExists = true
@@ -128,7 +128,7 @@ func (r *RoomserverInternalAPI) QueryStateAfterEvents(
 
 	// Look up the currrent state for the requested tuples.
 	stateEntries, err := roomState.LoadStateAfterEventsForStringTuples(
-		ctx, roomNID, prevStates, request.StateToFetch,
+		ctx, info.RoomNID, prevStates, request.StateToFetch,
 	)
 	if err != nil {
 		return err
@@ -737,20 +737,15 @@ func (r *RoomserverInternalAPI) QueryStateAndAuthChain(
 	request *api.QueryStateAndAuthChainRequest,
 	response *api.QueryStateAndAuthChainResponse,
 ) error {
-	roomNID, err := r.DB.RoomNIDExcludingStubs(ctx, request.RoomID)
+	info, err := r.DB.RoomInfo(ctx, request.RoomID)
 	if err != nil {
 		return err
 	}
-	if roomNID == 0 {
+	if info.IsStub {
 		return nil
 	}
 	response.RoomExists = true
-
+	response.RoomVersion = info.RoomVersion
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, request.RoomID)
-	if err != nil {
-		return err
-	}
-	response.RoomVersion = roomVersion
 
 	stateEvents, err := r.loadStateAtEventIDs(ctx, request.PrevEventIDs)
 	if err != nil {
@@ -773,18 +768,18 @@ func (r *RoomserverInternalAPI) QueryStateAndAuthChain(
 
 	if request.ResolveState {
 		if stateEvents, err = state.ResolveConflictsAdhoc(
-			roomVersion, stateEvents, authEvents,
+			info.RoomVersion, stateEvents, authEvents,
 		); err != nil {
 			return err
 		}
 	}
 
 	for _, event := range stateEvents {
-		response.StateEvents = append(response.StateEvents, event.Headered(roomVersion))
+		response.StateEvents = append(response.StateEvents, event.Headered(info.RoomVersion))
 	}
 
 	for _, event := range authEvents {
-		response.AuthChainEvents = append(response.AuthChainEvents, event.Headered(roomVersion))
+		response.AuthChainEvents = append(response.AuthChainEvents, event.Headered(info.RoomVersion))
 	}
 
 	return err

roomserver/storage/interface.go

@@ -26,6 +26,8 @@ import (
 type Database interface {
 	// Do we support processing input events for more than one room at a time?
 	SupportsConcurrentRoomInputs() bool
+	// RoomInfo returns room information for the given room ID, or nil if there is no room.
+	RoomInfo(ctx context.Context, roomID string) (*types.RoomInfo, error)
 	// Store the room state at an event in the database
 	AddState(
 		ctx context.Context,
@@ -98,10 +100,6 @@ type Database interface {
 	// Returns 0 if the room doesn't exists.
 	// Returns an error if there was a problem talking to the database.
 	RoomNID(ctx context.Context, roomID string) (types.RoomNID, error)
-	// RoomNIDExcludingStubs is a special variation of RoomNID that will return 0 as if the room
-	// does not exist if the room has no latest events. This can happen when we've received an
-	// invite over federation for a room that we don't know anything else about yet.
-	RoomNIDExcludingStubs(ctx context.Context, roomID string) (types.RoomNID, error)
 	// Look up event references for the latest events in the room and the current state snapshot.
 	// Returns the latest events, the current state and the maximum depth of the latest events plus 1.
 	// Returns an error if there was a problem talking to the database.

roomserver/storage/postgres/rooms_table.go

@@ -74,6 +74,9 @@ const selectRoomVersionForRoomIDSQL = "" +
 const selectRoomVersionForRoomNIDSQL = "" +
 	"SELECT room_version FROM roomserver_rooms WHERE room_nid = $1"
 
+const selectRoomInfoSQL = "" +
+	"SELECT room_version, room_nid, state_snapshot_nid, latest_event_nids FROM roomserver_rooms WHERE room_id = $1"
+
 type roomStatements struct {
 	insertRoomNIDStmt                  *sql.Stmt
 	selectRoomNIDStmt                  *sql.Stmt
@@ -82,6 +85,7 @@ type roomStatements struct {
 	updateLatestEventNIDsStmt          *sql.Stmt
 	selectRoomVersionForRoomIDStmt     *sql.Stmt
 	selectRoomVersionForRoomNIDStmt    *sql.Stmt
+	selectRoomInfoStmt                 *sql.Stmt
 }
 
 func NewPostgresRoomsTable(db *sql.DB) (tables.Rooms, error) {
@@ -98,6 +102,7 @@ func NewPostgresRoomsTable(db *sql.DB) (tables.Rooms, error) {
 		{&s.updateLatestEventNIDsStmt, updateLatestEventNIDsSQL},
 		{&s.selectRoomVersionForRoomIDStmt, selectRoomVersionForRoomIDSQL},
 		{&s.selectRoomVersionForRoomNIDStmt, selectRoomVersionForRoomNIDSQL},
+		{&s.selectRoomInfoStmt, selectRoomInfoSQL},
 	}.Prepare(db)
 }
 
@@ -111,6 +116,19 @@ func (s *roomStatements) InsertRoomNID(
 	return types.RoomNID(roomNID), err
 }
 
+func (s *roomStatements) SelectRoomInfo(ctx context.Context, roomID string) (*types.RoomInfo, error) {
+	var info types.RoomInfo
+	var latestNIDs pq.Int64Array
+	err := s.selectRoomInfoStmt.QueryRowContext(ctx, roomID).Scan(
+		&info.RoomVersion, &info.RoomNID, &info.StateSnapshotNID, &latestNIDs,
+	)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	info.IsStub = len(latestNIDs) == 0
+	return &info, err
+}
+
 func (s *roomStatements) SelectRoomNID(
 	ctx context.Context, txn *sql.Tx, roomID string,
 ) (types.RoomNID, error) {

roomserver/storage/shared/storage.go

@@ -120,6 +120,10 @@ func (d *Database) StateEntriesForTuples(
 	)
 }
 
+func (d *Database) RoomInfo(ctx context.Context, roomID string) (*types.RoomInfo, error) {
+	return d.RoomsTable.SelectRoomInfo(ctx, roomID)
+}
+
 func (d *Database) AddState(
 	ctx context.Context,
 	roomNID types.RoomNID,
@@ -206,22 +210,6 @@ func (d *Database) RoomNID(ctx context.Context, roomID string) (types.RoomNID, e
 	return roomNID, err
 }
 
-func (d *Database) RoomNIDExcludingStubs(ctx context.Context, roomID string) (roomNID types.RoomNID, err error) {
-	roomNID, err = d.RoomNID(ctx, roomID)
-	if err != nil {
-		return
-	}
-	latestEvents, _, err := d.RoomsTable.SelectLatestEventNIDs(ctx, nil, roomNID)
-	if err != nil {
-		return
-	}
-	if len(latestEvents) == 0 {
-		roomNID = 0
-		return
-	}
-	return
-}
-
 func (d *Database) LatestEventIDs(
 	ctx context.Context, roomNID types.RoomNID,
 ) (references []gomatrixserverlib.EventReference, currentStateSnapshotNID types.StateSnapshotNID, depth int64, err error) {

roomserver/storage/sqlite3/rooms_table.go

@@ -64,6 +64,9 @@ const selectRoomVersionForRoomIDSQL = "" +
 const selectRoomVersionForRoomNIDSQL = "" +
 	"SELECT room_version FROM roomserver_rooms WHERE room_nid = $1"
 
+const selectRoomInfoSQL = "" +
+	"SELECT room_version, room_nid, state_snapshot_nid, latest_event_nids FROM roomserver_rooms WHERE room_id = $1"
+
 type roomStatements struct {
 	db                                 *sql.DB
 	insertRoomNIDStmt                  *sql.Stmt
@@ -73,6 +76,7 @@ type roomStatements struct {
 	updateLatestEventNIDsStmt          *sql.Stmt
 	selectRoomVersionForRoomIDStmt     *sql.Stmt
 	selectRoomVersionForRoomNIDStmt    *sql.Stmt
+	selectRoomInfoStmt                 *sql.Stmt
 }
 
 func NewSqliteRoomsTable(db *sql.DB) (tables.Rooms, error) {
@@ -91,9 +95,30 @@ func NewSqliteRoomsTable(db *sql.DB) (tables.Rooms, error) {
 		{&s.updateLatestEventNIDsStmt, updateLatestEventNIDsSQL},
 		{&s.selectRoomVersionForRoomIDStmt, selectRoomVersionForRoomIDSQL},
 		{&s.selectRoomVersionForRoomNIDStmt, selectRoomVersionForRoomNIDSQL},
+		{&s.selectRoomInfoStmt, selectRoomInfoSQL},
 	}.Prepare(db)
 }
 
+func (s *roomStatements) SelectRoomInfo(ctx context.Context, roomID string) (*types.RoomInfo, error) {
+	var info types.RoomInfo
+	var latestNIDsJSON string
+	err := s.selectRoomInfoStmt.QueryRowContext(ctx, roomID).Scan(
+		&info.RoomVersion, &info.RoomNID, &info.StateSnapshotNID, &latestNIDsJSON,
+	)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, nil
+		}
+		return nil, err
+	}
+	var latestNIDs []int64
+	if err = json.Unmarshal([]byte(latestNIDsJSON), &latestNIDs); err != nil {
+		return nil, err
+	}
+	info.IsStub = len(latestNIDs) == 0
+	return &info, err
+}
+
 func (s *roomStatements) InsertRoomNID(
 	ctx context.Context, txn *sql.Tx,
 	roomID string, roomVersion gomatrixserverlib.RoomVersion,

roomserver/storage/tables/interface.go

@@ -65,6 +65,7 @@ type Rooms interface {
 	UpdateLatestEventNIDs(ctx context.Context, txn *sql.Tx, roomNID types.RoomNID, eventNIDs []types.EventNID, lastEventSentNID types.EventNID, stateSnapshotNID types.StateSnapshotNID) error
 	SelectRoomVersionForRoomID(ctx context.Context, txn *sql.Tx, roomID string) (gomatrixserverlib.RoomVersion, error)
 	SelectRoomVersionForRoomNID(ctx context.Context, roomNID types.RoomNID) (gomatrixserverlib.RoomVersion, error)
+	SelectRoomInfo(ctx context.Context, roomID string) (*types.RoomInfo, error)
 }
 
 type Transactions interface {

roomserver/types/types.go

@@ -144,3 +144,11 @@ type StateEntryList struct {
 type MissingEventError string
 
 func (e MissingEventError) Error() string { return string(e) }
+
+// RoomInfo contains metadata about a room
+type RoomInfo struct {
+	RoomNID          RoomNID
+	RoomVersion      gomatrixserverlib.RoomVersion
+	StateSnapshotNID StateSnapshotNID
+	IsStub           bool
+}