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

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
-	if err := json.Unmarshal(request.Content(), &builder); err != nil {
+	var proto gomatrixserverlib.ProtoEvent
+	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
-	builder.PrevEvents = queryRes.LatestEvents
+	protoEvent.Depth = queryRes.Depth
+	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 {