Use ProtoEvent where needed instead of EventBuilder (#3075)

They are fundamentally different concepts, so should be represented as
such. Proto events are exchanged in /make_xxx calls over federation, and
made as "fledgling" events in /createRoom and general event sending.
*Building* events is a reasonably complex VERSION SPECIFIC process which
needs amongst other things, auth event providers, prev events, signing
keys, etc.

Requires https://github.com/matrix-org/gomatrixserverlib/pull/379

clientapi/routing/createroom.go

@@ -433,18 +433,26 @@ func createRoom(
 	// TODO: invite events
 	// TODO: 3pid invite events
 
+	verImpl, err := gomatrixserverlib.GetRoomVersion(roomVersion)
+	if err != nil {
+		return util.JSONResponse{
+			Code: http.StatusBadRequest,
+			JSON: jsonerror.BadJSON("unknown room version"),
+		}
+	}
+
 	var builtEvents []*types.HeaderedEvent
 	authEvents := gomatrixserverlib.NewAuthEvents(nil)
 	for i, e := range eventsToMake {
 		depth := i + 1 // depth starts at 1
 
-		builder := gomatrixserverlib.EventBuilder{
+		builder := verImpl.NewEventBuilderFromProtoEvent(&gomatrixserverlib.ProtoEvent{
 			Sender:   userID,
 			RoomID:   roomID,
 			Type:     e.Type,
 			StateKey: &e.StateKey,
 			Depth:    int64(depth),
-		}
+		})
 		err = builder.SetContent(e.Content)
 		if err != nil {
 			util.GetLogger(ctx).WithError(err).Error("builder.SetContent failed")
@@ -454,7 +462,11 @@ func createRoom(
 			builder.PrevEvents = []gomatrixserverlib.EventReference{builtEvents[i-1].EventReference()}
 		}
 		var ev gomatrixserverlib.PDU
-		ev, err = builder.AddAuthEventsAndBuild(userDomain, &authEvents, evTime, roomVersion, cfg.Matrix.KeyID, cfg.Matrix.PrivateKey)
+		if err = builder.AddAuthEvents(&authEvents); err != nil {
+			util.GetLogger(ctx).WithError(err).Error("AddAuthEvents failed")
+			return jsonerror.InternalServerError()
+		}
+		ev, err = builder.Build(evTime, userDomain, cfg.Matrix.KeyID, cfg.Matrix.PrivateKey)
 		if err != nil {
 			util.GetLogger(ctx).WithError(err).Error("buildEvent failed")
 			return jsonerror.InternalServerError()

clientapi/routing/membership.go

@@ -313,7 +313,7 @@ func buildMembershipEvent(
 		return nil, err
 	}
 
-	builder := gomatrixserverlib.EventBuilder{
+	proto := gomatrixserverlib.ProtoEvent{
 		Sender:   device.UserID,
 		RoomID:   roomID,
 		Type:     "m.room.member",
@@ -328,7 +328,7 @@ func buildMembershipEvent(
 		IsDirect:    isDirect,
 	}
 
-	if err = builder.SetContent(content); err != nil {
+	if err = proto.SetContent(content); err != nil {
 		return nil, err
 	}
 
@@ -337,7 +337,7 @@ func buildMembershipEvent(
 		return nil, err
 	}
 
-	return eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, identity, evTime, rsAPI, nil)
+	return eventutil.QueryAndBuildEvent(ctx, &proto, cfg.Matrix, identity, evTime, rsAPI, nil)
 }
 
 // loadProfile lookups the profile of a given user from the database and returns

clientapi/routing/profile.go

@@ -339,7 +339,7 @@ func buildMembershipEvents(
 	evs := []*types.HeaderedEvent{}
 
 	for _, roomID := range roomIDs {
-		builder := gomatrixserverlib.EventBuilder{
+		proto := gomatrixserverlib.ProtoEvent{
 			Sender:   userID,
 			RoomID:   roomID,
 			Type:     "m.room.member",
@@ -353,7 +353,7 @@ func buildMembershipEvents(
 		content.DisplayName = newProfile.DisplayName
 		content.AvatarURL = newProfile.AvatarURL
 
-		if err := builder.SetContent(content); err != nil {
+		if err := proto.SetContent(content); err != nil {
 			return nil, err
 		}
 
@@ -362,7 +362,7 @@ func buildMembershipEvents(
 			return nil, err
 		}
 
-		event, err := eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, identity, evTime, rsAPI, nil)
+		event, err := eventutil.QueryAndBuildEvent(ctx, &proto, cfg.Matrix, identity, evTime, rsAPI, nil)
 		if err != nil {
 			return nil, err
 		}

clientapi/routing/redaction.go

@@ -113,15 +113,15 @@ func SendRedaction(
 	}
 
 	// create the new event and set all the fields we can
-	builder := gomatrixserverlib.EventBuilder{
+	proto := gomatrixserverlib.ProtoEvent{
 		Sender:  device.UserID,
 		RoomID:  roomID,
 		Type:    spec.MRoomRedaction,
 		Redacts: eventID,
 	}
-	err := builder.SetContent(r)
+	err := proto.SetContent(r)
 	if err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("builder.SetContent failed")
+		util.GetLogger(req.Context()).WithError(err).Error("proto.SetContent failed")
 		return jsonerror.InternalServerError()
 	}
 
@@ -131,7 +131,7 @@ func SendRedaction(
 	}
 
 	var queryRes roomserverAPI.QueryLatestEventsAndStateResponse
-	e, err := eventutil.QueryAndBuildEvent(req.Context(), &builder, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
+	e, err := eventutil.QueryAndBuildEvent(req.Context(), &proto, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,

clientapi/routing/sendevent.go

@@ -264,15 +264,15 @@ func generateSendEvent(
 	userID := device.UserID
 
 	// create the new event and set all the fields we can
-	builder := gomatrixserverlib.EventBuilder{
+	proto := gomatrixserverlib.ProtoEvent{
 		Sender:   userID,
 		RoomID:   roomID,
 		Type:     eventType,
 		StateKey: stateKey,
 	}
-	err := builder.SetContent(r)
+	err := proto.SetContent(r)
 	if err != nil {
-		util.GetLogger(ctx).WithError(err).Error("builder.SetContent failed")
+		util.GetLogger(ctx).WithError(err).Error("proto.SetContent failed")
 		resErr := jsonerror.InternalServerError()
 		return nil, &resErr
 	}
@@ -284,7 +284,7 @@ func generateSendEvent(
 	}
 
 	var queryRes api.QueryLatestEventsAndStateResponse
-	e, err := eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, identity, evTime, rsAPI, &queryRes)
+	e, err := eventutil.QueryAndBuildEvent(ctx, &proto, cfg.Matrix, identity, evTime, rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return nil, &util.JSONResponse{
 			Code: http.StatusNotFound,

clientapi/threepid/invites.go

@@ -335,7 +335,7 @@ func emit3PIDInviteEvent(
 	rsAPI api.ClientRoomserverAPI,
 	evTime time.Time,
 ) error {
-	builder := &gomatrixserverlib.EventBuilder{
+	proto := &gomatrixserverlib.ProtoEvent{
 		Sender:   device.UserID,
 		RoomID:   roomID,
 		Type:     "m.room.third_party_invite",
@@ -350,7 +350,7 @@ func emit3PIDInviteEvent(
 		PublicKeys:     res.PublicKeys,
 	}
 
-	if err := builder.SetContent(content); err != nil {
+	if err := proto.SetContent(content); err != nil {
 		return err
 	}
 
@@ -360,7 +360,7 @@ func emit3PIDInviteEvent(
 	}
 
 	queryRes := api.QueryLatestEventsAndStateResponse{}
-	event, err := eventutil.QueryAndBuildEvent(ctx, builder, cfg.Matrix, identity, evTime, rsAPI, &queryRes)
+	event, err := eventutil.QueryAndBuildEvent(ctx, proto, cfg.Matrix, identity, evTime, rsAPI, &queryRes)
 	if err != nil {
 		return err
 	}

federationapi/federationapi_test.go

@@ -113,7 +113,7 @@ func (f *fedClient) MakeJoin(ctx context.Context, origin, s spec.ServerName, roo
 	for _, r := range f.allowJoins {
 		if r.ID == roomID {
 			res.RoomVersion = r.Version
-			res.JoinEvent = gomatrixserverlib.EventBuilder{
+			res.JoinEvent = gomatrixserverlib.ProtoEvent{
 				Sender:     userID,
 				RoomID:     roomID,
 				Type:       "m.room.member",
@@ -122,7 +122,7 @@ func (f *fedClient) MakeJoin(ctx context.Context, origin, s spec.ServerName, roo
 				PrevEvents: r.ForwardExtremities(),
 			}
 			var needed gomatrixserverlib.StateNeeded
-			needed, err = gomatrixserverlib.StateNeededForEventBuilder(&res.JoinEvent)
+			needed, err = gomatrixserverlib.StateNeededForProtoEvent(&res.JoinEvent)
 			if err != nil {
 				f.t.Errorf("StateNeededForEventBuilder: %v", err)
 				return

federationapi/internal/perform.go

@@ -439,7 +439,7 @@ func (r *FederationInternalAPI) PerformLeave(
 
 		// Work out if we support the room version that has been supplied in
 		// the make_leave response.
-		_, err = gomatrixserverlib.GetRoomVersion(respMakeLeave.RoomVersion)
+		verImpl, err := gomatrixserverlib.GetRoomVersion(respMakeLeave.RoomVersion)
 		if err != nil {
 			return err
 		}
@@ -451,27 +451,28 @@ func (r *FederationInternalAPI) PerformLeave(
 		respMakeLeave.LeaveEvent.StateKey = &request.UserID
 		respMakeLeave.LeaveEvent.RoomID = request.RoomID
 		respMakeLeave.LeaveEvent.Redacts = ""
+		leaveEB := verImpl.NewEventBuilderFromProtoEvent(&respMakeLeave.LeaveEvent)
+
 		if respMakeLeave.LeaveEvent.Content == nil {
 			content := map[string]interface{}{
 				"membership": "leave",
 			}
-			if err = respMakeLeave.LeaveEvent.SetContent(content); err != nil {
+			if err = leaveEB.SetContent(content); err != nil {
 				logrus.WithError(err).Warnf("respMakeLeave.LeaveEvent.SetContent failed")
 				continue
 			}
 		}
-		if err = respMakeLeave.LeaveEvent.SetUnsigned(struct{}{}); err != nil {
+		if err = leaveEB.SetUnsigned(struct{}{}); err != nil {
 			logrus.WithError(err).Warnf("respMakeLeave.LeaveEvent.SetUnsigned failed")
 			continue
 		}
 
 		// Build the leave event.
-		event, err := respMakeLeave.LeaveEvent.Build(
+		event, err := leaveEB.Build(
 			time.Now(),
 			origin,
 			r.cfg.Matrix.KeyID,
 			r.cfg.Matrix.PrivateKey,
-			respMakeLeave.RoomVersion,
 		)
 		if err != nil {
 			logrus.WithError(err).Warnf("respMakeLeave.LeaveEvent.Build failed")

federationapi/routing/join.go

@@ -118,7 +118,7 @@ func MakeJoin(
 	}
 
 	// Try building an event for the server
-	builder := gomatrixserverlib.EventBuilder{
+	proto := gomatrixserverlib.ProtoEvent{
 		Sender:   userID,
 		RoomID:   roomID,
 		Type:     "m.room.member",
@@ -128,7 +128,7 @@ func MakeJoin(
 		Membership:    spec.Join,
 		AuthorisedVia: authorisedVia,
 	}
-	if err = builder.SetContent(content); err != nil {
+	if err = proto.SetContent(content); err != nil {
 		util.GetLogger(httpReq.Context()).WithError(err).Error("builder.SetContent failed")
 		return jsonerror.InternalServerError()
 	}
@@ -146,7 +146,7 @@ func MakeJoin(
 	queryRes := api.QueryLatestEventsAndStateResponse{
 		RoomVersion: roomVersion,
 	}
-	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &builder, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
+	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &proto, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,
@@ -179,7 +179,7 @@ func MakeJoin(
 	return util.JSONResponse{
 		Code: http.StatusOK,
 		JSON: map[string]interface{}{
-			"event":        builder,
+			"event":        proto,
 			"room_version": roomVersion,
 		},
 	}

federationapi/routing/leave.go

@@ -52,15 +52,15 @@ func MakeLeave(
 	}
 
 	// Try building an event for the server
-	builder := gomatrixserverlib.EventBuilder{
+	proto := gomatrixserverlib.ProtoEvent{
 		Sender:   userID,
 		RoomID:   roomID,
 		Type:     "m.room.member",
 		StateKey: &userID,
 	}
-	err = builder.SetContent(map[string]interface{}{"membership": spec.Leave})
+	err = proto.SetContent(map[string]interface{}{"membership": spec.Leave})
 	if err != nil {
-		util.GetLogger(httpReq.Context()).WithError(err).Error("builder.SetContent failed")
+		util.GetLogger(httpReq.Context()).WithError(err).Error("proto.SetContent failed")
 		return jsonerror.InternalServerError()
 	}
 
@@ -75,7 +75,7 @@ func MakeLeave(
 	}
 
 	var queryRes api.QueryLatestEventsAndStateResponse
-	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &builder, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
+	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &proto, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,
@@ -126,7 +126,7 @@ func MakeLeave(
 		Code: http.StatusOK,
 		JSON: map[string]interface{}{
 			"room_version": event.Version(),
-			"event":        builder,
+			"event":        proto,
 		},
 	}
 }

federationapi/routing/threepid.go

@@ -121,8 +121,8 @@ func ExchangeThirdPartyInvite(
 	cfg *config.FederationAPI,
 	federation fclient.FederationClient,
 ) util.JSONResponse {
-	var builder gomatrixserverlib.EventBuilder
+	var proto gomatrixserverlib.ProtoEvent
-	if err := json.Unmarshal(request.Content(), &builder); err != nil {
+	if err := json.Unmarshal(request.Content(), &proto); err != nil {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: jsonerror.NotJSON("The request body could not be decoded into valid JSON. " + err.Error()),
@@ -130,14 +130,14 @@ func ExchangeThirdPartyInvite(
 	}
 
 	// Check that the room ID is correct.
-	if builder.RoomID != roomID {
+	if proto.RoomID != roomID {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: jsonerror.BadJSON("The room ID in the request path must match the room ID in the invite event JSON"),
 		}
 	}
 
-	_, senderDomain, err := cfg.Matrix.SplitLocalID('@', builder.Sender)
+	_, senderDomain, err := cfg.Matrix.SplitLocalID('@', proto.Sender)
 	if err != nil {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
@@ -146,7 +146,7 @@ func ExchangeThirdPartyInvite(
 	}
 
 	// Check that the state key is correct.
-	_, targetDomain, err := gomatrixserverlib.SplitID('@', *builder.StateKey)
+	_, targetDomain, err := gomatrixserverlib.SplitID('@', *proto.StateKey)
 	if err != nil {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
@@ -171,7 +171,7 @@ func ExchangeThirdPartyInvite(
 	}
 
 	// Auth and build the event from what the remote server sent us
-	event, err := buildMembershipEvent(httpReq.Context(), &builder, rsAPI, cfg)
+	event, err := buildMembershipEvent(httpReq.Context(), &proto, rsAPI, cfg)
 	if err == errNotInRoom {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,
@@ -248,7 +248,7 @@ func createInviteFrom3PIDInvite(
 	}
 
 	// Build the event
-	builder := &gomatrixserverlib.EventBuilder{
+	proto := &gomatrixserverlib.ProtoEvent{
 		Type:     "m.room.member",
 		Sender:   inv.Sender,
 		RoomID:   inv.RoomID,
@@ -269,13 +269,13 @@ func createInviteFrom3PIDInvite(
 		},
 	}
 
-	if err = builder.SetContent(content); err != nil {
+	if err = proto.SetContent(content); err != nil {
 		return nil, err
 	}
 
-	event, err := buildMembershipEvent(ctx, builder, rsAPI, cfg)
+	event, err := buildMembershipEvent(ctx, proto, rsAPI, cfg)
 	if err == errNotInRoom {
-		return nil, sendToRemoteServer(ctx, inv, federation, cfg, *builder)
+		return nil, sendToRemoteServer(ctx, inv, federation, cfg, *proto)
 	}
 	if err != nil {
 		return nil, err
@@ -291,10 +291,10 @@ func createInviteFrom3PIDInvite(
 // Returns an error if something failed during the process.
 func buildMembershipEvent(
 	ctx context.Context,
-	builder *gomatrixserverlib.EventBuilder, rsAPI api.FederationRoomserverAPI,
+	protoEvent *gomatrixserverlib.ProtoEvent, rsAPI api.FederationRoomserverAPI,
 	cfg *config.FederationAPI,
 ) (gomatrixserverlib.PDU, error) {
-	eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(builder)
+	eventsNeeded, err := gomatrixserverlib.StateNeededForProtoEvent(protoEvent)
 	if err != nil {
 		return nil, err
 	}
@@ -305,7 +305,7 @@ func buildMembershipEvent(
 
 	// Ask the roomserver for information about this room
 	queryReq := api.QueryLatestEventsAndStateRequest{
-		RoomID:       builder.RoomID,
+		RoomID:       protoEvent.RoomID,
 		StateToFetch: eventsNeeded.Tuples(),
 	}
 	var queryRes api.QueryLatestEventsAndStateResponse
@@ -319,8 +319,8 @@ func buildMembershipEvent(
 	}
 
 	// Auth the event locally
-	builder.Depth = queryRes.Depth
+	protoEvent.Depth = queryRes.Depth
-	builder.PrevEvents = queryRes.LatestEvents
+	protoEvent.PrevEvents = queryRes.LatestEvents
 
 	authEvents := gomatrixserverlib.NewAuthEvents(nil)
 
@@ -331,7 +331,7 @@ func buildMembershipEvent(
 		}
 	}
 
-	if err = fillDisplayName(builder, authEvents); err != nil {
+	if err = fillDisplayName(protoEvent, authEvents); err != nil {
 		return nil, err
 	}
 
@@ -339,11 +339,17 @@ func buildMembershipEvent(
 	if err != nil {
 		return nil, err
 	}
-	builder.AuthEvents = refs
+	protoEvent.AuthEvents = refs
+
+	verImpl, err := gomatrixserverlib.GetRoomVersion(queryRes.RoomVersion)
+	if err != nil {
+		return nil, err
+	}
+	builder := verImpl.NewEventBuilderFromProtoEvent(protoEvent)
 
 	event, err := builder.Build(
 		time.Now(), cfg.Matrix.ServerName, cfg.Matrix.KeyID,
-		cfg.Matrix.PrivateKey, queryRes.RoomVersion,
+		cfg.Matrix.PrivateKey,
 	)
 
 	return event, err
@@ -357,7 +363,7 @@ func buildMembershipEvent(
 func sendToRemoteServer(
 	ctx context.Context, inv invite,
 	federation fclient.FederationClient, cfg *config.FederationAPI,
-	builder gomatrixserverlib.EventBuilder,
+	proto gomatrixserverlib.ProtoEvent,
 ) (err error) {
 	remoteServers := make([]spec.ServerName, 2)
 	_, remoteServers[0], err = gomatrixserverlib.SplitID('@', inv.Sender)
@@ -372,7 +378,7 @@ func sendToRemoteServer(
 	}
 
 	for _, server := range remoteServers {
-		err = federation.ExchangeThirdPartyInvite(ctx, cfg.Matrix.ServerName, server, builder)
+		err = federation.ExchangeThirdPartyInvite(ctx, cfg.Matrix.ServerName, server, proto)
 		if err == nil {
 			return
 		}
@@ -393,7 +399,7 @@ func sendToRemoteServer(
 // found. Returning an error isn't necessary in this case as the event will be
 // rejected by gomatrixserverlib.
 func fillDisplayName(
-	builder *gomatrixserverlib.EventBuilder, authEvents gomatrixserverlib.AuthEvents,
+	builder *gomatrixserverlib.ProtoEvent, authEvents gomatrixserverlib.AuthEvents,
 ) error {
 	var content gomatrixserverlib.MemberContent
 	if err := json.Unmarshal(builder.Content, &content); err != nil {

go.mod

@@ -22,7 +22,7 @@ require (
 	github.com/matrix-org/dugong v0.0.0-20210921133753-66e6b1c67e2e
 	github.com/matrix-org/go-sqlite3-js v0.0.0-20220419092513-28aa791a1c91
 	github.com/matrix-org/gomatrix v0.0.0-20220926102614-ceba4d9f7530
-	github.com/matrix-org/gomatrixserverlib v0.0.0-20230503081352-9e29bff996eb
+	github.com/matrix-org/gomatrixserverlib v0.0.0-20230504085954-69034410deb1
 	github.com/matrix-org/pinecone v0.11.1-0.20230210171230-8c3b24f2649a
 	github.com/matrix-org/util v0.0.0-20221111132719-399730281e66
 	github.com/mattn/go-sqlite3 v1.14.16

go.sum

@@ -333,6 +333,8 @@ github.com/matrix-org/gomatrixserverlib v0.0.0-20230502133856-ad26780a085c h1:5x
 github.com/matrix-org/gomatrixserverlib v0.0.0-20230502133856-ad26780a085c/go.mod h1:7HTbSZe+CIdmeqVyFMekwD5dFU8khWQyngKATvd12FU=
 github.com/matrix-org/gomatrixserverlib v0.0.0-20230503081352-9e29bff996eb h1:qg9iR39ctvB7A4hBcddjxmHQO/t3y4mpQnpmEc3xvNI=
 github.com/matrix-org/gomatrixserverlib v0.0.0-20230503081352-9e29bff996eb/go.mod h1:7HTbSZe+CIdmeqVyFMekwD5dFU8khWQyngKATvd12FU=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20230504085954-69034410deb1 h1:K0wM4rUNdqzWVQ54am8IeQn1q6f03sTNvhUW+ZaK1Zs=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20230504085954-69034410deb1/go.mod h1:7HTbSZe+CIdmeqVyFMekwD5dFU8khWQyngKATvd12FU=
 github.com/matrix-org/pinecone v0.11.1-0.20230210171230-8c3b24f2649a h1:awrPDf9LEFySxTLKYBMCiObelNx/cBuv/wzllvCCH3A=
 github.com/matrix-org/pinecone v0.11.1-0.20230210171230-8c3b24f2649a/go.mod h1:HchJX9oKMXaT2xYFs0Ha/6Zs06mxLU8k6F1ODnrGkeQ=
 github.com/matrix-org/util v0.0.0-20221111132719-399730281e66 h1:6z4KxomXSIGWqhHcfzExgkH3Z3UkIXry4ibJS4Aqz2Y=

internal/eventutil/events.go

@@ -41,7 +41,7 @@ var ErrRoomNoExists = errors.New("room does not exist")
 // Returns an error if something else went wrong
 func QueryAndBuildEvent(
 	ctx context.Context,
-	builder *gomatrixserverlib.EventBuilder, cfg *config.Global,
+	proto *gomatrixserverlib.ProtoEvent, cfg *config.Global,
 	identity *fclient.SigningIdentity, evTime time.Time,
 	rsAPI api.QueryLatestEventsAndStateAPI, queryRes *api.QueryLatestEventsAndStateResponse,
 ) (*types.HeaderedEvent, error) {
@@ -49,29 +49,35 @@ func QueryAndBuildEvent(
 		queryRes = &api.QueryLatestEventsAndStateResponse{}
 	}
 
-	eventsNeeded, err := queryRequiredEventsForBuilder(ctx, builder, rsAPI, queryRes)
+	eventsNeeded, err := queryRequiredEventsForBuilder(ctx, proto, rsAPI, queryRes)
 	if err != nil {
 		// This can pass through a ErrRoomNoExists to the caller
 		return nil, err
 	}
-	return BuildEvent(ctx, builder, cfg, identity, evTime, eventsNeeded, queryRes)
+	return BuildEvent(ctx, proto, cfg, identity, evTime, eventsNeeded, queryRes)
 }
 
 // BuildEvent builds a Matrix event from the builder and QueryLatestEventsAndStateResponse
 // provided.
 func BuildEvent(
 	ctx context.Context,
-	builder *gomatrixserverlib.EventBuilder, cfg *config.Global,
+	proto *gomatrixserverlib.ProtoEvent, cfg *config.Global,
 	identity *fclient.SigningIdentity, evTime time.Time,
 	eventsNeeded *gomatrixserverlib.StateNeeded, queryRes *api.QueryLatestEventsAndStateResponse,
 ) (*types.HeaderedEvent, error) {
-	if err := addPrevEventsToEvent(builder, eventsNeeded, queryRes); err != nil {
+	if err := addPrevEventsToEvent(proto, eventsNeeded, queryRes); err != nil {
 		return nil, err
 	}
 
+	verImpl, err := gomatrixserverlib.GetRoomVersion(queryRes.RoomVersion)
+	if err != nil {
+		return nil, err
+	}
+	builder := verImpl.NewEventBuilderFromProtoEvent(proto)
+
 	event, err := builder.Build(
 		evTime, identity.ServerName, identity.KeyID,
-		identity.PrivateKey, queryRes.RoomVersion,
+		identity.PrivateKey,
 	)
 	if err != nil {
 		return nil, err
@@ -83,12 +89,12 @@ func BuildEvent(
 // queryRequiredEventsForBuilder queries the roomserver for auth/prev events needed for this builder.
 func queryRequiredEventsForBuilder(
 	ctx context.Context,
-	builder *gomatrixserverlib.EventBuilder,
+	proto *gomatrixserverlib.ProtoEvent,
 	rsAPI api.QueryLatestEventsAndStateAPI, queryRes *api.QueryLatestEventsAndStateResponse,
 ) (*gomatrixserverlib.StateNeeded, error) {
-	eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(builder)
+	eventsNeeded, err := gomatrixserverlib.StateNeededForProtoEvent(proto)
 	if err != nil {
-		return nil, fmt.Errorf("gomatrixserverlib.StateNeededForEventBuilder: %w", err)
+		return nil, fmt.Errorf("gomatrixserverlib.StateNeededForProtoEvent: %w", err)
 	}
 
 	if len(eventsNeeded.Tuples()) == 0 {
@@ -97,7 +103,7 @@ func queryRequiredEventsForBuilder(
 
 	// Ask the roomserver for information about this room
 	queryReq := api.QueryLatestEventsAndStateRequest{
-		RoomID:       builder.RoomID,
+		RoomID:       proto.RoomID,
 		StateToFetch: eventsNeeded.Tuples(),
 	}
 	return &eventsNeeded, rsAPI.QueryLatestEventsAndState(ctx, &queryReq, queryRes)
@@ -105,7 +111,7 @@ func queryRequiredEventsForBuilder(
 
 // addPrevEventsToEvent fills out the prev_events and auth_events fields in builder
 func addPrevEventsToEvent(
-	builder *gomatrixserverlib.EventBuilder,
+	builder *gomatrixserverlib.ProtoEvent,
 	eventsNeeded *gomatrixserverlib.StateNeeded,
 	queryRes *api.QueryLatestEventsAndStateResponse,
 ) error {

roomserver/internal/alias.go

@@ -187,7 +187,7 @@ func (r *RoomserverInternalAPI) RemoveRoomAlias(
 				return err
 			}
 
-			builder := &gomatrixserverlib.EventBuilder{
+			proto := &gomatrixserverlib.ProtoEvent{
 				Sender:   sender,
 				RoomID:   ev.RoomID(),
 				Type:     ev.Type(),
@@ -195,7 +195,7 @@ func (r *RoomserverInternalAPI) RemoveRoomAlias(
 				Content:  res,
 			}
 
-			eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(builder)
+			eventsNeeded, err := gomatrixserverlib.StateNeededForProtoEvent(proto)
 			if err != nil {
 				return fmt.Errorf("gomatrixserverlib.StateNeededForEventBuilder: %w", err)
 			}
@@ -208,7 +208,7 @@ func (r *RoomserverInternalAPI) RemoveRoomAlias(
 				return err
 			}
 
-			newEvent, err := eventutil.BuildEvent(ctx, builder, &r.Cfg.Global, identity, time.Now(), &eventsNeeded, stateRes)
+			newEvent, err := eventutil.BuildEvent(ctx, proto, &r.Cfg.Global, identity, time.Now(), &eventsNeeded, stateRes)
 			if err != nil {
 				return err
 			}

roomserver/internal/input/input_events.go

@@ -852,7 +852,7 @@ func (r *Inputer) kickGuests(ctx context.Context, event gomatrixserverlib.PDU, r
 		memberContent.Membership = spec.Leave
 
 		stateKey := *memberEvent.StateKey()
-		fledglingEvent := &gomatrixserverlib.EventBuilder{
+		fledglingEvent := &gomatrixserverlib.ProtoEvent{
 			RoomID:     event.RoomID(),
 			Type:       spec.MRoomMember,
 			StateKey:   &stateKey,
@@ -864,7 +864,7 @@ func (r *Inputer) kickGuests(ctx context.Context, event gomatrixserverlib.PDU, r
 			return err
 		}
 
-		eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(fledglingEvent)
+		eventsNeeded, err := gomatrixserverlib.StateNeededForProtoEvent(fledglingEvent)
 		if err != nil {
 			return err
 		}

roomserver/internal/perform/perform_admin.go

@@ -92,7 +92,7 @@ func (r *Admin) PerformAdminEvacuateRoom(
 		memberContent.Membership = spec.Leave
 
 		stateKey := *memberEvent.StateKey()
-		fledglingEvent := &gomatrixserverlib.EventBuilder{
+		fledglingEvent := &gomatrixserverlib.ProtoEvent{
 			RoomID:     roomID,
 			Type:       spec.MRoomMember,
 			StateKey:   &stateKey,
@@ -109,7 +109,7 @@ func (r *Admin) PerformAdminEvacuateRoom(
 			return nil, err
 		}
 
-		eventsNeeded, err = gomatrixserverlib.StateNeededForEventBuilder(fledglingEvent)
+		eventsNeeded, err = gomatrixserverlib.StateNeededForProtoEvent(fledglingEvent)
 		if err != nil {
 			return nil, err
 		}
@@ -283,16 +283,16 @@ func (r *Admin) PerformAdminDownloadState(
 		stateIDs = append(stateIDs, stateEvent.EventID())
 	}
 
-	builder := &gomatrixserverlib.EventBuilder{
+	proto := &gomatrixserverlib.ProtoEvent{
 		Type:    "org.matrix.dendrite.state_download",
 		Sender:  userID,
 		RoomID:  roomID,
 		Content: spec.RawJSON("{}"),
 	}
 
-	eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(builder)
+	eventsNeeded, err := gomatrixserverlib.StateNeededForProtoEvent(proto)
 	if err != nil {
-		return fmt.Errorf("gomatrixserverlib.StateNeededForEventBuilder: %w", err)
+		return fmt.Errorf("gomatrixserverlib.StateNeededForProtoEvent: %w", err)
 	}
 
 	queryRes := &api.QueryLatestEventsAndStateResponse{
@@ -308,7 +308,7 @@ func (r *Admin) PerformAdminDownloadState(
 		return err
 	}
 
-	ev, err := eventutil.BuildEvent(ctx, builder, r.Cfg.Matrix, identity, time.Now(), &eventsNeeded, queryRes)
+	ev, err := eventutil.BuildEvent(ctx, proto, r.Cfg.Matrix, identity, time.Now(), &eventsNeeded, queryRes)
 	if err != nil {
 		return fmt.Errorf("eventutil.BuildEvent: %w", err)
 	}

roomserver/internal/perform/perform_join.go

@@ -180,14 +180,14 @@ func (r *Joiner) performJoinRoomByID(
 	if err != nil {
 		return "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("user ID %q is invalid: %w", userID, err)}
 	}
-	eb := gomatrixserverlib.EventBuilder{
+	proto := gomatrixserverlib.ProtoEvent{
 		Type:     spec.MRoomMember,
 		Sender:   userID,
 		StateKey: &userID,
 		RoomID:   req.RoomIDOrAlias,
 		Redacts:  "",
 	}
-	if err = eb.SetUnsigned(struct{}{}); err != nil {
+	if err = proto.SetUnsigned(struct{}{}); err != nil {
 		return "", "", fmt.Errorf("eb.SetUnsigned: %w", err)
 	}
 
@@ -203,7 +203,7 @@ func (r *Joiner) performJoinRoomByID(
 	} else if authorisedVia != "" {
 		req.Content["join_authorised_via_users_server"] = authorisedVia
 	}
-	if err = eb.SetContent(req.Content); err != nil {
+	if err = proto.SetContent(req.Content); err != nil {
 		return "", "", fmt.Errorf("eb.SetContent: %w", err)
 	}
 
@@ -284,7 +284,7 @@ func (r *Joiner) performJoinRoomByID(
 	if err != nil {
 		return "", "", fmt.Errorf("error joining local room: %q", err)
 	}
-	event, err := eventutil.QueryAndBuildEvent(ctx, &eb, r.Cfg.Matrix, identity, time.Now(), r.RSAPI, &buildRes)
+	event, err := eventutil.QueryAndBuildEvent(ctx, &proto, r.Cfg.Matrix, identity, time.Now(), r.RSAPI, &buildRes)
 
 	switch err {
 	case nil:

roomserver/internal/perform/perform_leave.go

@@ -154,24 +154,24 @@ func (r *Leaver) performLeaveRoomByID(
 
 	// Prepare the template for the leave event.
 	userID := req.UserID
-	eb := gomatrixserverlib.EventBuilder{
+	proto := gomatrixserverlib.ProtoEvent{
 		Type:     spec.MRoomMember,
 		Sender:   userID,
 		StateKey: &userID,
 		RoomID:   req.RoomID,
 		Redacts:  "",
 	}
-	if err = eb.SetContent(map[string]interface{}{"membership": "leave"}); err != nil {
+	if err = proto.SetContent(map[string]interface{}{"membership": "leave"}); err != nil {
 		return nil, fmt.Errorf("eb.SetContent: %w", err)
 	}
-	if err = eb.SetUnsigned(struct{}{}); err != nil {
+	if err = proto.SetUnsigned(struct{}{}); err != nil {
 		return nil, fmt.Errorf("eb.SetUnsigned: %w", err)
 	}
 
 	// Get the sender domain.
-	_, senderDomain, serr := r.Cfg.Matrix.SplitLocalID('@', eb.Sender)
+	_, senderDomain, serr := r.Cfg.Matrix.SplitLocalID('@', proto.Sender)
 	if serr != nil {
-		return nil, fmt.Errorf("sender %q is invalid", eb.Sender)
+		return nil, fmt.Errorf("sender %q is invalid", proto.Sender)
 	}
 
 	// We know that the user is in the room at this point so let's build
@@ -184,7 +184,7 @@ func (r *Leaver) performLeaveRoomByID(
 	if err != nil {
 		return nil, fmt.Errorf("SigningIdentityFor: %w", err)
 	}
-	event, err := eventutil.QueryAndBuildEvent(ctx, &eb, r.Cfg.Matrix, identity, time.Now(), r.RSAPI, &buildRes)
+	event, err := eventutil.QueryAndBuildEvent(ctx, &proto, r.Cfg.Matrix, identity, time.Now(), r.RSAPI, &buildRes)
 	if err != nil {
 		return nil, fmt.Errorf("eventutil.QueryAndBuildEvent: %w", err)
 	}

roomserver/internal/perform/perform_upgrade.go

@@ -459,22 +459,33 @@ func (r *Upgrader) sendInitialEvents(ctx context.Context, evTime time.Time, user
 	for i, e := range eventsToMake {
 		depth := i + 1 // depth starts at 1
 
-		builder := gomatrixserverlib.EventBuilder{
+		proto := gomatrixserverlib.ProtoEvent{
 			Sender:   userID,
 			RoomID:   newRoomID,
 			Type:     e.Type,
 			StateKey: &e.StateKey,
 			Depth:    int64(depth),
 		}
-		err = builder.SetContent(e.Content)
+		err = proto.SetContent(e.Content)
 		if err != nil {
-			return fmt.Errorf("failed to set content of new %q event: %w", builder.Type, err)
+			return fmt.Errorf("failed to set content of new %q event: %w", proto.Type, err)
 		}
 		if i > 0 {
-			builder.PrevEvents = []gomatrixserverlib.EventReference{builtEvents[i-1].EventReference()}
+			proto.PrevEvents = []gomatrixserverlib.EventReference{builtEvents[i-1].EventReference()}
 		}
+
+		var verImpl gomatrixserverlib.IRoomVersion
+		verImpl, err = gomatrixserverlib.GetRoomVersion(newVersion)
+		if err != nil {
+			return err
+		}
+		builder := verImpl.NewEventBuilderFromProtoEvent(&proto)
+		if err = builder.AddAuthEvents(&authEvents); err != nil {
+			return err
+		}
+
 		var event gomatrixserverlib.PDU
-		event, err = builder.AddAuthEventsAndBuild(userDomain, &authEvents, evTime, newVersion, r.Cfg.Matrix.KeyID, r.Cfg.Matrix.PrivateKey)
+		event, err = builder.Build(evTime, userDomain, r.Cfg.Matrix.KeyID, r.Cfg.Matrix.PrivateKey)
 		if err != nil {
 			return fmt.Errorf("failed to build new %q event: %w", builder.Type, err)
 
@@ -524,27 +535,27 @@ func (r *Upgrader) makeTombstoneEvent(
 }
 
 func (r *Upgrader) makeHeaderedEvent(ctx context.Context, evTime time.Time, userID, roomID string, event fledglingEvent) (*types.HeaderedEvent, error) {
-	builder := gomatrixserverlib.EventBuilder{
+	proto := gomatrixserverlib.ProtoEvent{
 		Sender:   userID,
 		RoomID:   roomID,
 		Type:     event.Type,
 		StateKey: &event.StateKey,
 	}
-	err := builder.SetContent(event.Content)
+	err := proto.SetContent(event.Content)
 	if err != nil {
-		return nil, fmt.Errorf("failed to set new %q event content: %w", builder.Type, err)
+		return nil, fmt.Errorf("failed to set new %q event content: %w", proto.Type, err)
 	}
 	// Get the sender domain.
-	_, senderDomain, serr := r.Cfg.Matrix.SplitLocalID('@', builder.Sender)
+	_, senderDomain, serr := r.Cfg.Matrix.SplitLocalID('@', proto.Sender)
 	if serr != nil {
-		return nil, fmt.Errorf("Failed to split user ID %q: %w", builder.Sender, err)
+		return nil, fmt.Errorf("Failed to split user ID %q: %w", proto.Sender, err)
 	}
 	identity, err := r.Cfg.Matrix.SigningIdentityFor(senderDomain)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get signing identity for %q: %w", senderDomain, err)
 	}
 	var queryRes api.QueryLatestEventsAndStateResponse
-	headeredEvent, err := eventutil.QueryAndBuildEvent(ctx, &builder, r.Cfg.Matrix, identity, evTime, r.URSAPI, &queryRes)
+	headeredEvent, err := eventutil.QueryAndBuildEvent(ctx, &proto, r.Cfg.Matrix, identity, evTime, r.URSAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return nil, err
 	} else if e, ok := err.(gomatrixserverlib.BadJSONError); ok {
@@ -552,7 +563,7 @@ func (r *Upgrader) makeHeaderedEvent(ctx context.Context, evTime time.Time, user
 	} else if e, ok := err.(gomatrixserverlib.EventValidationError); ok {
 		return nil, e
 	} else if err != nil {
-		return nil, fmt.Errorf("failed to build new %q event: %w", builder.Type, err)
+		return nil, fmt.Errorf("failed to build new %q event: %w", proto.Type, err)
 	}
 	// check to see if this user can perform this operation
 	stateEvents := make([]gomatrixserverlib.PDU, len(queryRes.StateEvents))
@@ -561,7 +572,7 @@ func (r *Upgrader) makeHeaderedEvent(ctx context.Context, evTime time.Time, user
 	}
 	provider := gomatrixserverlib.NewAuthEvents(stateEvents)
 	if err = gomatrixserverlib.Allowed(headeredEvent.PDU, &provider); err != nil {
-		return nil, api.ErrNotAllowed{Err: fmt.Errorf("failed to auth new %q event: %w", builder.Type, err)} // TODO: Is this error string comprehensible to the client?
+		return nil, api.ErrNotAllowed{Err: fmt.Errorf("failed to auth new %q event: %w", proto.Type, err)} // TODO: Is this error string comprehensible to the client?
 	}
 
 	return headeredEvent, nil

roomserver/roomserver_test.go

@@ -404,7 +404,7 @@ func mustCreateEvent(t *testing.T, ev fledglingEvent) (result *types.HeaderedEve
 	roomVer := gomatrixserverlib.RoomVersionV9
 	seed := make([]byte, ed25519.SeedSize) // zero seed
 	key := ed25519.NewKeyFromSeed(seed)
-	eb := gomatrixserverlib.EventBuilder{
+	eb := gomatrixserverlib.MustGetRoomVersion(roomVer).NewEventBuilderFromProtoEvent(&gomatrixserverlib.ProtoEvent{
 		Sender:     ev.Sender,
 		Type:       ev.Type,
 		StateKey:   ev.StateKey,
@@ -412,12 +412,13 @@ func mustCreateEvent(t *testing.T, ev fledglingEvent) (result *types.HeaderedEve
 		Redacts:    ev.Redacts,
 		Depth:      ev.Depth,
 		PrevEvents: ev.PrevEvents,
-	}
+	})
 	err := eb.SetContent(map[string]interface{}{})
 	if err != nil {
 		t.Fatalf("mustCreateEvent: failed to marshal event content %v", err)
 	}
-	signedEvent, err := eb.Build(time.Now(), "localhost", "ed25519:test", key, roomVer)
+
+	signedEvent, err := eb.Build(time.Now(), "localhost", "ed25519:test", key)
 	if err != nil {
 		t.Fatalf("mustCreateEvent: failed to sign event: %s", err)
 	}

setup/mscs/msc2836/msc2836_test.go

@@ -585,20 +585,20 @@ func mustCreateEvent(t *testing.T, ev fledglingEvent) (result *types.HeaderedEve
 	roomVer := gomatrixserverlib.RoomVersionV6
 	seed := make([]byte, ed25519.SeedSize) // zero seed
 	key := ed25519.NewKeyFromSeed(seed)
-	eb := gomatrixserverlib.EventBuilder{
+	eb := gomatrixserverlib.MustGetRoomVersion(roomVer).NewEventBuilderFromProtoEvent(&gomatrixserverlib.ProtoEvent{
 		Sender:   ev.Sender,
 		Depth:    999,
 		Type:     ev.Type,
 		StateKey: ev.StateKey,
 		RoomID:   ev.RoomID,
-	}
+	})
 	err := eb.SetContent(ev.Content)
 	if err != nil {
 		t.Fatalf("mustCreateEvent: failed to marshal event content %+v", ev.Content)
 	}
 	// make sure the origin_server_ts changes so we can test recency
 	time.Sleep(1 * time.Millisecond)
-	signedEvent, err := eb.Build(time.Now(), spec.ServerName("localhost"), "ed25519:test", key, roomVer)
+	signedEvent, err := eb.Build(time.Now(), spec.ServerName("localhost"), "ed25519:test", key)
 	if err != nil {
 		t.Fatalf("mustCreateEvent: failed to sign event: %s", err)
 	}

test/room.go

@@ -163,14 +163,14 @@ func (r *Room) CreateEvent(t *testing.T, creator *User, eventType string, conten
 		}
 	}
 
-	builder := &gomatrixserverlib.EventBuilder{
+	builder := gomatrixserverlib.MustGetRoomVersion(r.Version).NewEventBuilderFromProtoEvent(&gomatrixserverlib.ProtoEvent{
 		Sender:   creator.ID,
 		RoomID:   r.ID,
 		Type:     eventType,
 		StateKey: mod.stateKey,
 		Depth:    int64(depth),
 		Unsigned: unsigned,
-	}
+	})
 	err = builder.SetContent(content)
 	if err != nil {
 		t.Fatalf("CreateEvent[%s]: failed to SetContent: %s", eventType, err)
@@ -179,16 +179,10 @@ func (r *Room) CreateEvent(t *testing.T, creator *User, eventType string, conten
 		builder.PrevEvents = []gomatrixserverlib.EventReference{r.events[len(r.events)-1].EventReference()}
 	}
 
-	eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(builder)
+	err = builder.AddAuthEvents(&r.authEvents)
-	if err != nil {
-		t.Fatalf("CreateEvent[%s]: failed to StateNeededForEventBuilder: %s", eventType, err)
-	}
-
-	refs, err := eventsNeeded.AuthEventReferences(&r.authEvents)
 	if err != nil {
 		t.Fatalf("CreateEvent[%s]: failed to AuthEventReferences: %s", eventType, err)
 	}
-	builder.AuthEvents = refs
 
 	if len(mod.authEvents) > 0 {
 		builder.AuthEvents = mod.authEvents
@@ -196,7 +190,7 @@ func (r *Room) CreateEvent(t *testing.T, creator *User, eventType string, conten
 
 	ev, err := builder.Build(
 		mod.originServerTS, mod.origin, mod.keyID,
-		mod.privKey, r.Version,
+		mod.privKey,
 	)
 	if err != nil {
 		t.Fatalf("CreateEvent[%s]: failed to build event: %s", eventType, err)