Replace some helpers.IsServerCurrentlyInRoom calls with query API

roomserver/internal/api.go

@@ -93,6 +93,7 @@ func (r *RoomserverInternalAPI) SetFederationSenderAPI(fsAPI fsAPI.FederationSen
 		FSAPI:      r.fsAPI,
 		RSAPI:      r,
 		Inputer:    r.Inputer,
+		Queryer:    r.Queryer,
 	}
 	r.Peeker = &perform.Peeker{
 		ServerName: r.Cfg.Matrix.ServerName,

roomserver/internal/helpers/helpers.go

@@ -50,6 +50,10 @@ func UpdateToInviteMembership(
 	return updates, nil
 }
 
+// IsServerCurrentlyInRoom checks if a server is in a given room, based on the room
+// memberships. If the servername is not supplied then the local server will be
+// checked instead using a faster code path.
+// TODO: This should probably be replaced by an API call.
 func IsServerCurrentlyInRoom(ctx context.Context, db storage.Database, serverName gomatrixserverlib.ServerName, roomID string) (bool, error) {
 	info, err := db.RoomInfo(ctx, roomID)
 	if err != nil {
@@ -59,6 +63,10 @@ func IsServerCurrentlyInRoom(ctx context.Context, db storage.Database, serverNam
 		return false, fmt.Errorf("unknown room %s", roomID)
 	}
 
+	if serverName == "" {
+		return db.GetLocalServerInRoom(ctx, info.RoomNID)
+	}
+
 	eventNIDs, err := db.GetMembershipEventNIDsForRoom(ctx, info.RoomNID, true, false)
 	if err != nil {
 		return false, err

roomserver/internal/perform/perform_join.go

@@ -28,6 +28,7 @@ import (
 	rsAPI "github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/roomserver/internal/helpers"
 	"github.com/matrix-org/dendrite/roomserver/internal/input"
+	"github.com/matrix-org/dendrite/roomserver/internal/query"
 	"github.com/matrix-org/dendrite/roomserver/storage"
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/gomatrixserverlib"
@@ -42,6 +43,7 @@ type Joiner struct {
 	DB         storage.Database
 
 	Inputer *input.Inputer
+	Queryer *query.Queryer
 }
 
 // PerformJoin handles joining matrix rooms, including over federation by talking to the federationsender.
@@ -205,7 +207,14 @@ func (r *Joiner) performJoinRoomByID(
 
 	// Force a federated join if we aren't in the room and we've been
 	// given some server names to try joining by.
-	serverInRoom, _ := helpers.IsServerCurrentlyInRoom(ctx, r.DB, r.ServerName, req.RoomIDOrAlias)
+	inRoomReq := &api.QueryServerJoinedToRoomRequest{
+		RoomID: req.RoomIDOrAlias,
+	}
+	inRoomRes := &api.QueryServerJoinedToRoomResponse{}
+	if err = r.Queryer.QueryServerJoinedToRoom(ctx, inRoomReq, inRoomRes); err != nil {
+		return "", "", fmt.Errorf("r.Queryer.QueryServerJoinedToRoom: %w", err)
+	}
+	serverInRoom := inRoomRes.IsInRoom
 	forceFederatedJoin := len(req.ServerNames) > 0 && !serverInRoom
 
 	// Force a federated join if we're dealing with a pending invite

roomserver/internal/query/query.go

@@ -388,10 +388,16 @@ func (r *Queryer) QueryServerAllowedToSeeEvent(
 		return
 	}
 	roomID := events[0].RoomID()
-	isServerInRoom, err := helpers.IsServerCurrentlyInRoom(ctx, r.DB, request.ServerName, roomID)
-	if err != nil {
-		return
+
+	inRoomReq := &api.QueryServerJoinedToRoomRequest{
+		RoomID:     roomID,
+		ServerName: request.ServerName,
 	}
+	inRoomRes := &api.QueryServerJoinedToRoomResponse{}
+	if err = r.QueryServerJoinedToRoom(ctx, inRoomReq, inRoomRes); err != nil {
+		return fmt.Errorf("r.Queryer.QueryServerJoinedToRoom: %w", err)
+	}
+
 	info, err := r.DB.RoomInfo(ctx, roomID)
 	if err != nil {
 		return err
@@ -400,7 +406,7 @@ func (r *Queryer) QueryServerAllowedToSeeEvent(
 		return fmt.Errorf("QueryServerAllowedToSeeEvent: no room info for room %s", roomID)
 	}
 	response.AllowedToSeeEvent, err = helpers.CheckServerAllowedToSeeEvent(
-		ctx, r.DB, *info, request.EventID, request.ServerName, isServerInRoom,
+		ctx, r.DB, *info, request.EventID, request.ServerName, inRoomRes.IsInRoom,
 	)
 	return
 }