Mangle everything so that room versions are now sent in the kafka events

appservice/consumers/roomserver.go

@@ -15,8 +15,10 @@
 package consumers
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 
 	"github.com/matrix-org/dendrite/appservice/storage"
 	"github.com/matrix-org/dendrite/appservice/types"
@@ -81,6 +83,30 @@ func (s *OutputRoomEventConsumer) Start() error {
 func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
 	// Parse out the event JSON
 	var output api.OutputEvent
+
+	// See if the room version is present in the headers. If it isn't
+	// then we can't process the event as we don't know what the format
+	// will be
+	var roomVersion gomatrixserverlib.RoomVersion
+	for _, header := range msg.Headers {
+		if bytes.Equal(header.Key, []byte("room_version")) {
+			roomVersion = gomatrixserverlib.RoomVersion(header.Value)
+			break
+		}
+	}
+	if roomVersion == "" {
+		return errors.New("room version was not in sarama headers")
+	}
+
+	// Prepare the room event so that it has the correct field types
+	// for the room version
+	if err := output.NewRoomEvent.Event.PrepareAs(roomVersion); err != nil {
+		log.WithFields(log.Fields{
+			"room_version": roomVersion,
+		}).WithError(err).Errorf("can't prepare event to version")
+		return err
+	}
+
 	if err := json.Unmarshal(msg.Value, &output); err != nil {
 		// If the message was invalid, log it and move on to the next message in the stream
 		log.WithError(err).Errorf("roomserver output log: message parse failure")
@@ -94,31 +120,6 @@ func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
 		return nil
 	}
 
-	// Get the room version of the room
-	vQueryReq := api.QueryRoomVersionForRoomIDRequest{RoomID: string(msg.Key)}
-	vQueryRes := api.QueryRoomVersionForRoomIDResponse{}
-	if err := s.query.QueryRoomVersionForRoomID(context.Background(), &vQueryReq, &vQueryRes); err != nil {
-		log.WithFields(log.Fields{
-			"room_id": string(msg.Key),
-		}).WithError(err).Errorf("can't query room version")
-		return err
-	}
-
-	// Prepare the room event so that it has the correct field types
-	// for the room version
-	if err := output.NewRoomEvent.Event.PrepareAs(vQueryRes.RoomVersion); err != nil {
-		log.WithFields(log.Fields{
-			"room_version": vQueryRes.RoomVersion,
-		}).WithError(err).Errorf("can't prepare event to version")
-		return err
-	}
-
-	if err := json.Unmarshal(msg.Value, &output); err != nil {
-		// If the message was invalid, log it and move on to the next message in the stream
-		log.WithError(err).Errorf("roomserver output log: message parse failure")
-		return nil
-	}
-
 	ev := output.NewRoomEvent.Event
 	log.WithFields(log.Fields{
 		"event_id": ev.EventID(),

federationsender/consumers/roomserver.go

@@ -15,8 +15,10 @@
 package consumers
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 
 	"github.com/matrix-org/dendrite/common"
@@ -74,6 +76,30 @@ func (s *OutputRoomEventConsumer) Start() error {
 func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
 	// Parse out the event JSON
 	var output api.OutputEvent
+
+	// See if the room version is present in the headers. If it isn't
+	// then we can't process the event as we don't know what the format
+	// will be
+	var roomVersion gomatrixserverlib.RoomVersion
+	for _, header := range msg.Headers {
+		if bytes.Equal(header.Key, []byte("room_version")) {
+			roomVersion = gomatrixserverlib.RoomVersion(header.Value)
+			break
+		}
+	}
+	if roomVersion == "" {
+		return errors.New("room version was not in sarama headers")
+	}
+
+	// Prepare the room event so that it has the correct field types
+	// for the room version
+	if err := output.NewRoomEvent.Event.PrepareAs(roomVersion); err != nil {
+		log.WithFields(log.Fields{
+			"room_version": roomVersion,
+		}).WithError(err).Errorf("can't prepare event to version")
+		return err
+	}
+
 	if err := json.Unmarshal(msg.Value, &output); err != nil {
 		// If the message was invalid, log it and move on to the next message in the stream
 		log.WithError(err).Errorf("roomserver output log: message parse failure")
@@ -87,31 +113,6 @@ func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
 		return nil
 	}
 
-	// Get the room version of the room
-	vQueryReq := api.QueryRoomVersionForRoomIDRequest{RoomID: string(msg.Key)}
-	vQueryRes := api.QueryRoomVersionForRoomIDResponse{}
-	if err := s.query.QueryRoomVersionForRoomID(context.Background(), &vQueryReq, &vQueryRes); err != nil {
-		log.WithFields(log.Fields{
-			"room_id": string(msg.Key),
-		}).WithError(err).Errorf("can't query room version")
-		return err
-	}
-
-	// Prepare the room event so that it has the correct field types
-	// for the room version
-	if err := output.NewRoomEvent.Event.PrepareAs(vQueryRes.RoomVersion); err != nil {
-		log.WithFields(log.Fields{
-			"room_version": vQueryRes.RoomVersion,
-		}).WithError(err).Errorf("can't prepare event to version")
-		return err
-	}
-
-	if err := json.Unmarshal(msg.Value, &output); err != nil {
-		// If the message was invalid, log it and move on to the next message in the stream
-		log.WithError(err).Errorf("roomserver output log: message parse failure")
-		return nil
-	}
-
 	ev := output.NewRoomEvent.Event
 	log.WithFields(log.Fields{
 		"event_id":       ev.EventID(),

publicroomsapi/consumers/roomserver.go

@@ -15,13 +15,16 @@
 package consumers
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 
 	"github.com/matrix-org/dendrite/common"
 	"github.com/matrix-org/dendrite/common/config"
 	"github.com/matrix-org/dendrite/publicroomsapi/storage"
 	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/gomatrixserverlib"
 	log "github.com/sirupsen/logrus"
 	sarama "gopkg.in/Shopify/sarama.v1"
 )
@@ -63,6 +66,30 @@ func (s *OutputRoomEventConsumer) Start() error {
 // onMessage is called when the sync server receives a new event from the room server output log.
 func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
 	var output api.OutputEvent
+
+	// See if the room version is present in the headers. If it isn't
+	// then we can't process the event as we don't know what the format
+	// will be
+	var roomVersion gomatrixserverlib.RoomVersion
+	for _, header := range msg.Headers {
+		if bytes.Equal(header.Key, []byte("room_version")) {
+			roomVersion = gomatrixserverlib.RoomVersion(header.Value)
+			break
+		}
+	}
+	if roomVersion == "" {
+		return errors.New("room version was not in sarama headers")
+	}
+
+	// Prepare the room event so that it has the correct field types
+	// for the room version
+	if err := output.NewRoomEvent.Event.PrepareAs(roomVersion); err != nil {
+		log.WithFields(log.Fields{
+			"room_version": roomVersion,
+		}).WithError(err).Errorf("can't prepare event to version")
+		return err
+	}
+
 	if err := json.Unmarshal(msg.Value, &output); err != nil {
 		// If the message was invalid, log it and move on to the next message in the stream
 		log.WithError(err).Errorf("roomserver output log: message parse failure")
@@ -77,32 +104,6 @@ func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
 		return nil
 	}
 
-	// Get the room version of the room
-	vQueryReq := api.QueryRoomVersionForRoomIDRequest{RoomID: string(msg.Key)}
-	vQueryRes := api.QueryRoomVersionForRoomIDResponse{}
-	if err := s.query.QueryRoomVersionForRoomID(context.Background(), &vQueryReq, &vQueryRes); err != nil {
-		log.WithFields(log.Fields{
-			"room_id": string(msg.Key),
-		}).WithError(err).Errorf("can't query room version")
-		return err
-	}
-
-	// Prepare the room event so that it has the correct field types
-	// for the room version
-	if err := output.NewRoomEvent.Event.PrepareAs(vQueryRes.RoomVersion); err != nil {
-		log.WithFields(log.Fields{
-			"room_version": vQueryRes.RoomVersion,
-		}).WithError(err).Errorf("can't prepare event to version")
-		return err
-	}
-
-	// Parse out the event JSON
-	if err := json.Unmarshal(msg.Value, &output); err != nil {
-		// If the message was invalid, log it and move on to the next message in the stream
-		log.WithError(err).Errorf("roomserver output log: message parse failure")
-		return nil
-	}
-
 	ev := output.NewRoomEvent.Event
 	log.WithFields(log.Fields{
 		"event_id": ev.EventID(),

roomserver/input/events.go

@@ -73,7 +73,10 @@ type RoomEventDatabase interface {
 		sessionID int64, userID string,
 	) (string, error)
 	// Look up the room version from the database.
-	GetRoomVersionForRoom(
+	GetRoomVersionForRoomID(
+		ctx context.Context, roomID string,
+	) (gomatrixserverlib.RoomVersion, error)
+	GetRoomVersionForRoomNID(
 		ctx context.Context, roomNID types.RoomNID,
 	) (gomatrixserverlib.RoomVersion, error)
 }
@@ -81,7 +84,7 @@ type RoomEventDatabase interface {
 // OutputRoomEventWriter has the APIs needed to write an event to the output logs.
 type OutputRoomEventWriter interface {
 	// Write a list of events for a room
-	WriteOutputEvents(roomID string, updates []api.OutputEvent) error
+	WriteOutputEvents(roomID string, roomVersion gomatrixserverlib.RoomVersion, updates []api.OutputEvent) error
 }
 
 // processRoomEvent can only be called once at a time
@@ -156,7 +159,7 @@ func calculateAndSetState(
 	stateAtEvent *types.StateAtEvent,
 	event gomatrixserverlib.Event,
 ) error {
-	roomVersion, err := db.GetRoomVersionForRoom(ctx, roomNID)
+	roomVersion, err := db.GetRoomVersionForRoomNID(ctx, roomNID)
 	if err != nil {
 		return err
 	}
@@ -196,6 +199,7 @@ func processInviteEvent(
 	}
 
 	roomID := input.Event.RoomID()
+	roomVersion := gomatrixserverlib.RoomVersionV1 // TODO: Feeeeeeex
 	targetUserID := *input.Event.StateKey()
 
 	updater, err := db.MembershipUpdater(ctx, roomID, targetUserID)
@@ -246,7 +250,7 @@ func processInviteEvent(
 		return err
 	}
 
-	if err = ow.WriteOutputEvents(roomID, outputUpdates); err != nil {
+	if err = ow.WriteOutputEvents(roomID, roomVersion, outputUpdates); err != nil {
 		return err
 	}
 

roomserver/input/input.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/matrix-org/dendrite/common"
 	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 	sarama "gopkg.in/Shopify/sarama.v1"
 )
@@ -39,7 +40,9 @@ type RoomserverInputAPI struct {
 }
 
 // WriteOutputEvents implements OutputRoomEventWriter
-func (r *RoomserverInputAPI) WriteOutputEvents(roomID string, updates []api.OutputEvent) error {
+func (r *RoomserverInputAPI) WriteOutputEvents(
+	roomID string, roomVersion gomatrixserverlib.RoomVersion, updates []api.OutputEvent,
+) error {
 	messages := make([]*sarama.ProducerMessage, len(updates))
 	for i := range updates {
 		value, err := json.Marshal(updates[i])
@@ -50,6 +53,12 @@ func (r *RoomserverInputAPI) WriteOutputEvents(roomID string, updates []api.Outp
 			Topic: r.OutputRoomEventTopic,
 			Key:   sarama.StringEncoder(roomID),
 			Value: sarama.ByteEncoder(value),
+			Headers: []sarama.RecordHeader{
+				sarama.RecordHeader{
+					Key:   []byte("room_version"),
+					Value: []byte(roomVersion),
+				},
+			},
 		}
 	}
 	return r.Producer.SendMessages(messages)

roomserver/input/latest_events.go

@@ -67,7 +67,7 @@ func updateLatestEvents(
 		}
 	}()
 
-	roomVersion, err := db.GetRoomVersionForRoom(ctx, roomNID)
+	roomVersion, err := db.GetRoomVersionForRoomNID(ctx, roomNID)
 	if err != nil {
 		return err
 	}
@@ -163,6 +163,8 @@ func (u *latestEventsUpdater) doUpdateLatestEvents() error {
 	}
 	updates = append(updates, *update)
 
+	roomVersion := gomatrixserverlib.RoomVersionV1
+
 	// Send the event to the output logs.
 	// We do this inside the database transaction to ensure that we only mark an event as sent if we sent it.
 	// (n.b. this means that it's possible that the same event will be sent twice if the transaction fails but
@@ -171,7 +173,7 @@ func (u *latestEventsUpdater) doUpdateLatestEvents() error {
 	// send the event asynchronously but we would need to ensure that 1) the events are written to the log in
 	// the correct order, 2) that pending writes are resent across restarts. In order to avoid writing all the
 	// necessary bookkeeping we'll keep the event sending synchronous for now.
-	if err = u.ow.WriteOutputEvents(u.event.RoomID(), updates); err != nil {
+	if err = u.ow.WriteOutputEvents(u.event.RoomID(), roomVersion, updates); err != nil {
 		return err
 	}
 
@@ -184,7 +186,7 @@ func (u *latestEventsUpdater) doUpdateLatestEvents() error {
 
 func (u *latestEventsUpdater) latestState() error {
 	var err error
-	roomVersion, err := u.db.GetRoomVersionForRoom(u.ctx, u.roomNID)
+	roomVersion, err := u.db.GetRoomVersionForRoomNID(u.ctx, u.roomNID)
 	if err != nil {
 		return err
 	}
@@ -262,7 +264,7 @@ func (u *latestEventsUpdater) makeOutputNewRoomEvent() (*api.OutputEvent, error)
 		latestEventIDs[i] = u.latest[i].EventID
 	}
 
-	roomVersion, err := u.db.GetRoomVersionForRoom(context.Background(), u.roomNID)
+	roomVersion, err := u.db.GetRoomVersionForRoomNID(context.Background(), u.roomNID)
 	if err != nil {
 		return nil, err
 	}

roomserver/query/query.go

@@ -90,7 +90,10 @@ type RoomserverQueryAPIDatabase interface {
 		context.Context, []types.EventStateKeyNID,
 	) (map[types.EventStateKeyNID]string, error)
 	// Look up the room version from the database.
-	GetRoomVersionForRoom(
+	GetRoomVersionForRoomID(
+		ctx context.Context, roomID string,
+	) (gomatrixserverlib.RoomVersion, error)
+	GetRoomVersionForRoomNID(
 		ctx context.Context, roomNID types.RoomNID,
 	) (gomatrixserverlib.RoomVersion, error)
 	// Get the room NID for a given event ID.
@@ -123,7 +126,7 @@ func (r *RoomserverQueryAPI) QueryLatestEventsAndState(
 		return nil
 	}
 	response.RoomExists = true
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomNID)
+	roomVersion, err := r.DB.GetRoomVersionForRoomID(ctx, request.RoomID)
 	if err != nil {
 		return err
 	}
@@ -170,7 +173,7 @@ func (r *RoomserverQueryAPI) QueryStateAfterEvents(
 		return nil
 	}
 	response.RoomExists = true
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomNID)
+	roomVersion, err := r.DB.GetRoomVersionForRoomID(ctx, request.RoomID)
 	if err != nil {
 		return err
 	}
@@ -350,7 +353,7 @@ func (r *RoomserverQueryAPI) getMembershipsBeforeEventNID(
 	if err != nil {
 		return nil, err
 	}
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomNID)
+	roomVersion, err := r.DB.GetRoomVersionForRoomNID(ctx, roomNID)
 	if err != nil {
 		return nil, err
 	}
@@ -464,7 +467,7 @@ func (r *RoomserverQueryAPI) checkServerAllowedToSeeEvent(
 	if err != nil {
 		return false, err
 	}
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomNID)
+	roomVersion, err := r.DB.GetRoomVersionForRoomNID(ctx, roomNID)
 	if err != nil {
 		return false, err
 	}
@@ -631,7 +634,7 @@ func (r *RoomserverQueryAPI) QueryStateAndAuthChain(
 	if err != nil {
 		return err
 	}
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomNID)
+	roomVersion, err := r.DB.GetRoomVersionForRoomID(ctx, request.RoomID)
 	if err != nil {
 		return err
 	}
@@ -786,14 +789,8 @@ func (r *RoomserverQueryAPI) QueryRoomVersionForRoomID(
 	request *api.QueryRoomVersionForRoomIDRequest,
 	response *api.QueryRoomVersionForRoomIDResponse,
 ) error {
-	// Get the room NID for the given room ID
-	roomNID, err := r.DB.RoomNID(ctx, request.RoomID)
-	if err != nil {
-		return err
-	}
-
 	// Then look up the room version for that room NID
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomNID)
+	roomVersion, err := r.DB.GetRoomVersionForRoomID(ctx, request.RoomID)
 	if err != nil {
 		return err
 	}

roomserver/storage/interface.go

@@ -45,7 +45,8 @@ type Database interface {
 	GetMembership(ctx context.Context, roomNID types.RoomNID, requestSenderUserID string) (membershipEventNID types.EventNID, stillInRoom bool, err error)
 	GetMembershipEventNIDsForRoom(ctx context.Context, roomNID types.RoomNID, joinOnly bool) ([]types.EventNID, error)
 	EventsFromIDs(ctx context.Context, eventIDs []string) ([]types.Event, error)
-	GetRoomVersionForRoom(ctx context.Context, roomNID types.RoomNID) (gomatrixserverlib.RoomVersion, error)
+	GetRoomVersionForRoomID(ctx context.Context, roomID string) (gomatrixserverlib.RoomVersion, error)
+	GetRoomVersionForRoomNID(ctx context.Context, roomNID types.RoomNID) (gomatrixserverlib.RoomVersion, error)
 	RoomNIDForEventID(ctx context.Context, eventID string) (types.RoomNID, error)
 	RoomNIDForEventNID(ctx context.Context, eventNID types.EventNID) (types.RoomNID, error)
 }

roomserver/storage/postgres/rooms_table.go

@@ -65,6 +65,9 @@ const selectLatestEventNIDsForUpdateSQL = "" +
 const updateLatestEventNIDsSQL = "" +
 	"UPDATE roomserver_rooms SET latest_event_nids = $2, last_event_sent_nid = $3, state_snapshot_nid = $4 WHERE room_nid = $1"
 
+const selectRoomVersionForRoomIDSQL = "" +
+	"SELECT room_version FROM roomserver_rooms WHERE room_id = $1"
+
 const selectRoomVersionForRoomNIDSQL = "" +
 	"SELECT room_version FROM roomserver_rooms WHERE room_nid = $1"
 
@@ -74,6 +77,7 @@ type roomStatements struct {
 	selectLatestEventNIDsStmt          *sql.Stmt
 	selectLatestEventNIDsForUpdateStmt *sql.Stmt
 	updateLatestEventNIDsStmt          *sql.Stmt
+	selectRoomVersionForRoomIDStmt     *sql.Stmt
 	selectRoomVersionForRoomNIDStmt    *sql.Stmt
 }
 
@@ -88,6 +92,7 @@ func (s *roomStatements) prepare(db *sql.DB) (err error) {
 		{&s.selectLatestEventNIDsStmt, selectLatestEventNIDsSQL},
 		{&s.selectLatestEventNIDsForUpdateStmt, selectLatestEventNIDsForUpdateSQL},
 		{&s.updateLatestEventNIDsStmt, updateLatestEventNIDsSQL},
+		{&s.selectRoomVersionForRoomIDStmt, selectRoomVersionForRoomIDSQL},
 		{&s.selectRoomVersionForRoomNIDStmt, selectRoomVersionForRoomNIDSQL},
 	}.prepare(db)
 }
@@ -173,3 +178,12 @@ func (s *roomStatements) selectRoomVersionForRoomNID(
 	err := stmt.QueryRowContext(ctx, roomNID).Scan(&roomVersion)
 	return roomVersion, err
 }
+
+func (s *roomStatements) selectRoomVersionForRoomID(
+	ctx context.Context, txn *sql.Tx, roomID string,
+) (gomatrixserverlib.RoomVersion, error) {
+	var roomVersion gomatrixserverlib.RoomVersion
+	stmt := common.TxStmt(txn, s.selectRoomVersionForRoomIDStmt)
+	err := stmt.QueryRowContext(ctx, roomID).Scan(&roomVersion)
+	return roomVersion, err
+}

roomserver/storage/postgres/storage.go

@@ -237,7 +237,7 @@ func (d *Database) Events(
 		if err != nil {
 			return nil, err
 		}
-		roomVersion, err := d.GetRoomVersionForRoom(ctx, roomNID)
+		roomVersion, err := d.GetRoomVersionForRoomNID(ctx, roomNID)
 		if err != nil {
 			return nil, err
 		}
@@ -743,7 +743,15 @@ func (d *Database) EventsFromIDs(ctx context.Context, eventIDs []string) ([]type
 	return d.Events(ctx, nids)
 }
 
-func (d *Database) GetRoomVersionForRoom(
+func (d *Database) GetRoomVersionForRoomID(
+	ctx context.Context, roomID string,
+) (gomatrixserverlib.RoomVersion, error) {
+	return d.statements.selectRoomVersionForRoomID(
+		ctx, nil, roomID,
+	)
+}
+
+func (d *Database) GetRoomVersionForRoomNID(
 	ctx context.Context, roomNID types.RoomNID,
 ) (gomatrixserverlib.RoomVersion, error) {
 	return d.statements.selectRoomVersionForRoomNID(

roomserver/storage/sqlite3/rooms_table.go

@@ -54,6 +54,9 @@ const selectLatestEventNIDsForUpdateSQL = "" +
 const updateLatestEventNIDsSQL = "" +
 	"UPDATE roomserver_rooms SET latest_event_nids = $1, last_event_sent_nid = $2, state_snapshot_nid = $3 WHERE room_nid = $4"
 
+const selectRoomVersionForRoomIDSQL = "" +
+	"SELECT room_version FROM roomserver_rooms WHERE room_id = $1"
+
 const selectRoomVersionForRoomNIDSQL = "" +
 	"SELECT room_version FROM roomserver_rooms WHERE room_nid = $1"
 
@@ -63,6 +66,7 @@ type roomStatements struct {
 	selectLatestEventNIDsStmt          *sql.Stmt
 	selectLatestEventNIDsForUpdateStmt *sql.Stmt
 	updateLatestEventNIDsStmt          *sql.Stmt
+	selectRoomVersionForRoomIDStmt     *sql.Stmt
 	selectRoomVersionForRoomNIDStmt    *sql.Stmt
 }
 
@@ -77,6 +81,7 @@ func (s *roomStatements) prepare(db *sql.DB) (err error) {
 		{&s.selectLatestEventNIDsStmt, selectLatestEventNIDsSQL},
 		{&s.selectLatestEventNIDsForUpdateStmt, selectLatestEventNIDsForUpdateSQL},
 		{&s.updateLatestEventNIDsStmt, updateLatestEventNIDsSQL},
+		{&s.selectRoomVersionForRoomIDStmt, selectRoomVersionForRoomIDSQL},
 		{&s.selectRoomVersionForRoomNIDStmt, selectRoomVersionForRoomNIDSQL},
 	}.prepare(db)
 }
@@ -157,6 +162,15 @@ func (s *roomStatements) updateLatestEventNIDs(
 	return err
 }
 
+func (s *roomStatements) selectRoomVersionForRoomID(
+	ctx context.Context, txn *sql.Tx, roomID string,
+) (gomatrixserverlib.RoomVersion, error) {
+	var roomVersion gomatrixserverlib.RoomVersion
+	stmt := common.TxStmt(txn, s.selectRoomVersionForRoomIDStmt)
+	err := stmt.QueryRowContext(ctx, roomID).Scan(&roomVersion)
+	return roomVersion, err
+}
+
 func (s *roomStatements) selectRoomVersionForRoomNID(
 	ctx context.Context, txn *sql.Tx, roomNID types.RoomNID,
 ) (gomatrixserverlib.RoomVersion, error) {

roomserver/storage/sqlite3/storage.go

@@ -289,7 +289,7 @@ func (d *Database) Events(
 			if err != nil {
 				return err
 			}
-			roomVersion, err := d.GetRoomVersionForRoom(ctx, roomNID)
+			roomVersion, err := d.GetRoomVersionForRoomNID(ctx, roomNID)
 			if err != nil {
 				return err
 			}
@@ -896,7 +896,15 @@ func (d *Database) EventsFromIDs(ctx context.Context, eventIDs []string) ([]type
 	return d.Events(ctx, nids)
 }
 
-func (d *Database) GetRoomVersionForRoom(
+func (d *Database) GetRoomVersionForRoomID(
+	ctx context.Context, roomID string,
+) (gomatrixserverlib.RoomVersion, error) {
+	return d.statements.selectRoomVersionForRoomID(
+		ctx, nil, roomID,
+	)
+}
+
+func (d *Database) GetRoomVersionForRoomNID(
 	ctx context.Context, roomNID types.RoomNID,
 ) (gomatrixserverlib.RoomVersion, error) {
 	return d.statements.selectRoomVersionForRoomNID(

syncapi/consumers/roomserver.go

@@ -15,8 +15,10 @@
 package consumers
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 
 	"github.com/matrix-org/dendrite/common"
@@ -74,18 +76,54 @@ func (s *OutputRoomEventConsumer) Start() error {
 func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
 	// Parse out the event JSON
 	var output api.OutputEvent
-	if err := json.Unmarshal(msg.Value, &output); err != nil {
+
-		// If the message was invalid, log it and move on to the next message in the stream
+	// See if the room version is present in the headers. If it isn't
-		log.WithError(err).Errorf("roomserver output log: message parse failure")
+	// then we can't process the event as we don't know what the format
-		return nil
+	// will be
+	var roomVersion gomatrixserverlib.RoomVersion
+	for _, header := range msg.Headers {
+		if bytes.Equal(header.Key, []byte("room_version")) {
+			roomVersion = gomatrixserverlib.RoomVersion(header.Value)
+			break
+		}
+	}
+	if roomVersion == "" {
+		return errors.New("room version was not in sarama headers")
 	}
 
 	switch output.Type {
 	case api.OutputTypeNewRoomEvent:
+		if err := output.NewRoomEvent.Event.PrepareAs(roomVersion); err != nil {
+			log.WithFields(log.Fields{
+				"room_version": roomVersion,
+			}).WithError(err).Errorf("can't prepare event to version")
+			return err
+		}
+		if err := json.Unmarshal(msg.Value, &output); err != nil {
+			// If the message was invalid, log it and move on to the next message in the stream
+			log.WithError(err).Errorf("roomserver output log: message parse failure")
+			return nil
+		}
 		return s.onNewRoomEvent(context.TODO(), *output.NewRoomEvent)
 	case api.OutputTypeNewInviteEvent:
+		if err := output.NewInviteEvent.Event.PrepareAs(roomVersion); err != nil {
+			log.WithFields(log.Fields{
+				"room_version": roomVersion,
+			}).WithError(err).Errorf("can't prepare event to version")
+			return err
+		}
+		if err := json.Unmarshal(msg.Value, &output); err != nil {
+			// If the message was invalid, log it and move on to the next message in the stream
+			log.WithError(err).Errorf("roomserver output log: message parse failure")
+			return nil
+		}
 		return s.onNewInviteEvent(context.TODO(), *output.NewInviteEvent)
 	case api.OutputTypeRetireInviteEvent:
+		if err := json.Unmarshal(msg.Value, &output); err != nil {
+			// If the message was invalid, log it and move on to the next message in the stream
+			log.WithError(err).Errorf("roomserver output log: message parse failure")
+			return nil
+		}
 		return s.onRetireInviteEvent(context.TODO(), *output.RetireInviteEvent)
 	default:
 		log.WithField("type", output.Type).Debug(
@@ -100,13 +138,6 @@ func (s *OutputRoomEventConsumer) onNewRoomEvent(
 ) error {
 	ev := msg.Event
 
-	if err := msg.Event.PrepareAs(msg.RoomVersion); err != nil {
-		log.WithFields(log.Fields{
-			"room_version": msg.RoomVersion,
-		}).WithError(err).Errorf("can't prepare event to version")
-		return err
-	}
-
 	log.WithFields(log.Fields{
 		"event_id": ev.EventID(),
 		"room_id":  ev.RoomID(),