Merge branch 'master' into matthew/peeking

build.sh

@@ -3,6 +3,11 @@
 # Put installed packages into ./bin
 export GOBIN=$PWD/`dirname $0`/bin
 
-go install -v $PWD/`dirname $0`/cmd/...
+export BRANCH=`(git symbolic-ref --short HEAD | cut -d'/' -f 3 )|| ""`
+export BUILD=`git rev-parse --short HEAD || ""`
 
-GOOS=js GOARCH=wasm go build -o main.wasm ./cmd/dendritejs
+export FLAGS="-X github.com/matrix-org/dendrite/internal.branch=$BRANCH -X github.com/matrix-org/dendrite/internal.build=$BUILD"
+
+go install -trimpath -ldflags "$FLAGS" -v $PWD/`dirname $0`/cmd/...
+
+GOOS=js GOARCH=wasm go build -trimpath -ldflags "$FLAGS" -o main.wasm ./cmd/dendritejs

build/gobind/monolith.go

@@ -120,7 +120,7 @@ func (m *DendriteMonolith) Start() {
 	keyAPI.SetUserAPI(userAPI)
 
 	rsAPI := roomserver.NewInternalAPI(
-		base, keyRing, federation,
+		base, keyRing,
 	)
 
 	eduInputAPI := eduserver.NewInternalAPI(

build/scripts/Complement.Dockerfile

@@ -12,8 +12,7 @@ COPY . .
 RUN go build ./cmd/dendrite-monolith-server
 RUN go build ./cmd/generate-keys
 RUN go build ./cmd/generate-config
-RUN ./generate-config > dendrite.yaml
-RUN sed -i "s/disable_tls_validation: false/disable_tls_validation: true/g" dendrite.yaml
+RUN ./generate-config --ci > dendrite.yaml
 RUN ./generate-keys --private-key matrix_key.pem --tls-cert server.crt --tls-key server.key
 
 ENV SERVER_NAME=localhost

build/scripts/complement.sh

@@ -10,10 +10,10 @@ cd `dirname $0`/../..
 docker build -t complement-dendrite -f build/scripts/Complement.Dockerfile .
 
 # Download Complement
-wget https://github.com/matrix-org/complement/archive/master.tar.gz
+wget -N https://github.com/matrix-org/complement/archive/master.tar.gz
 tar -xzf master.tar.gz
 
 # Run the tests!
 cd complement-master
-COMPLEMENT_BASE_IMAGE=complement-dendrite:latest go test -v ./tests
+COMPLEMENT_BASE_IMAGE=complement-dendrite:latest go test -v -count=1 ./tests
 

clientapi/routing/createroom.go

@@ -342,8 +342,7 @@ func createRoom(
 	}
 
 	// send events to the room server
-	_, err = roomserverAPI.SendEvents(req.Context(), rsAPI, builtEvents, cfg.Matrix.ServerName, nil)
-	if err != nil {
+	if err = roomserverAPI.SendEvents(req.Context(), rsAPI, builtEvents, cfg.Matrix.ServerName, nil); err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("SendEvents failed")
 		return jsonerror.InternalServerError()
 	}

clientapi/routing/login.go

@@ -41,15 +41,13 @@ type flows struct {
 }
 
 type flow struct {
-	Type   string   `json:"type"`
-	Stages []string `json:"stages"`
+	Type string `json:"type"`
 }
 
 func passwordLogin() flows {
 	f := flows{}
 	s := flow{
-		Type:   "m.login.password",
-		Stages: []string{"m.login.password"},
+		Type: "m.login.password",
 	}
 	f.Flows = append(f.Flows, s)
 	return f

clientapi/routing/membership.go

@@ -75,13 +75,12 @@ func sendMembership(ctx context.Context, accountDB accounts.Database, device *us
 		return jsonerror.InternalServerError()
 	}
 
-	_, err = roomserverAPI.SendEvents(
+	if err = roomserverAPI.SendEvents(
 		ctx, rsAPI,
 		[]gomatrixserverlib.HeaderedEvent{event.Event.Headered(roomVer)},
 		cfg.Matrix.ServerName,
 		nil,
-	)
-	if err != nil {
+	); err != nil {
 		util.GetLogger(ctx).WithError(err).Error("SendEvents failed")
 		return jsonerror.InternalServerError()
 	}
@@ -270,7 +269,7 @@ func buildMembershipEvent(
 		return nil, err
 	}
 
-	return eventutil.BuildEvent(ctx, &builder, cfg.Matrix, evTime, rsAPI, nil)
+	return eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, evTime, rsAPI, nil)
 }
 
 // loadProfile lookups the profile of a given user from the database and returns

clientapi/routing/profile.go

@@ -171,7 +171,7 @@ func SetAvatarURL(
 		return jsonerror.InternalServerError()
 	}
 
-	if _, err := api.SendEvents(req.Context(), rsAPI, events, cfg.Matrix.ServerName, nil); err != nil {
+	if err := api.SendEvents(req.Context(), rsAPI, events, cfg.Matrix.ServerName, nil); err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("SendEvents failed")
 		return jsonerror.InternalServerError()
 	}
@@ -289,7 +289,7 @@ func SetDisplayName(
 		return jsonerror.InternalServerError()
 	}
 
-	if _, err := api.SendEvents(req.Context(), rsAPI, events, cfg.Matrix.ServerName, nil); err != nil {
+	if err := api.SendEvents(req.Context(), rsAPI, events, cfg.Matrix.ServerName, nil); err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("SendEvents failed")
 		return jsonerror.InternalServerError()
 	}
@@ -375,7 +375,7 @@ func buildMembershipEvents(
 			return nil, err
 		}
 
-		event, err := eventutil.BuildEvent(ctx, &builder, cfg.Matrix, evTime, rsAPI, nil)
+		event, err := eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, evTime, rsAPI, nil)
 		if err != nil {
 			return nil, err
 		}

clientapi/routing/rate_limiting.go

@@ -0,0 +1,99 @@
+package routing
+
+import (
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/internal/config"
+	"github.com/matrix-org/util"
+)
+
+type rateLimits struct {
+	limits           map[string]chan struct{}
+	limitsMutex      sync.RWMutex
+	enabled          bool
+	requestThreshold int64
+	cooloffDuration  time.Duration
+}
+
+func newRateLimits(cfg *config.RateLimiting) *rateLimits {
+	l := &rateLimits{
+		limits:           make(map[string]chan struct{}),
+		enabled:          cfg.Enabled,
+		requestThreshold: cfg.Threshold,
+		cooloffDuration:  time.Duration(cfg.CooloffMS) * time.Millisecond,
+	}
+	if l.enabled {
+		go l.clean()
+	}
+	return l
+}
+
+func (l *rateLimits) clean() {
+	for {
+		// On a 30 second interval, we'll take an exclusive write
+		// lock of the entire map and see if any of the channels are
+		// empty. If they are then we will close and delete them,
+		// freeing up memory.
+		time.Sleep(time.Second * 30)
+		l.limitsMutex.Lock()
+		for k, c := range l.limits {
+			if len(c) == 0 {
+				close(c)
+				delete(l.limits, k)
+			}
+		}
+		l.limitsMutex.Unlock()
+	}
+}
+
+func (l *rateLimits) rateLimit(req *http.Request) *util.JSONResponse {
+	// If rate limiting is disabled then do nothing.
+	if !l.enabled {
+		return nil
+	}
+
+	// Lock the map long enough to check for rate limiting. We hold it
+	// for longer here than we really need to but it makes sure that we
+	// also don't conflict with the cleaner goroutine which might clean
+	// up a channel after we have retrieved it otherwise.
+	l.limitsMutex.RLock()
+	defer l.limitsMutex.RUnlock()
+
+	// First of all, work out if X-Forwarded-For was sent to us. If not
+	// then we'll just use the IP address of the caller.
+	caller := req.RemoteAddr
+	if forwardedFor := req.Header.Get("X-Forwarded-For"); forwardedFor != "" {
+		caller = forwardedFor
+	}
+
+	// Look up the caller's channel, if they have one. If they don't then
+	// let's create one.
+	rateLimit, ok := l.limits[caller]
+	if !ok {
+		l.limits[caller] = make(chan struct{}, l.requestThreshold)
+		rateLimit = l.limits[caller]
+	}
+
+	// Check if the user has got free resource slots for this request.
+	// If they don't then we'll return an error.
+	select {
+	case rateLimit <- struct{}{}:
+	default:
+		// We hit the rate limit. Tell the client to back off.
+		return &util.JSONResponse{
+			Code: http.StatusTooManyRequests,
+			JSON: jsonerror.LimitExceeded("You are sending too many requests too quickly!", l.cooloffDuration.Milliseconds()),
+		}
+	}
+
+	// After the time interval, drain a resource from the rate limiting
+	// channel. This will free up space in the channel for new requests.
+	go func() {
+		<-time.After(l.cooloffDuration)
+		<-rateLimit
+	}()
+	return nil
+}

clientapi/routing/redaction.go

@@ -115,15 +115,14 @@ func SendRedaction(
 	}
 
 	var queryRes api.QueryLatestEventsAndStateResponse
-	e, err := eventutil.BuildEvent(req.Context(), &builder, cfg.Matrix, time.Now(), rsAPI, &queryRes)
+	e, err := eventutil.QueryAndBuildEvent(req.Context(), &builder, cfg.Matrix, time.Now(), rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,
 			JSON: jsonerror.NotFound("Room does not exist"),
 		}
 	}
-	_, err = roomserverAPI.SendEvents(context.Background(), rsAPI, []gomatrixserverlib.HeaderedEvent{*e}, cfg.Matrix.ServerName, nil)
-	if err != nil {
+	if err = roomserverAPI.SendEvents(context.Background(), rsAPI, []gomatrixserverlib.HeaderedEvent{*e}, cfg.Matrix.ServerName, nil); err != nil {
 		util.GetLogger(req.Context()).WithError(err).Errorf("failed to SendEvents")
 		return jsonerror.InternalServerError()
 	}

clientapi/routing/routing.go

@@ -60,6 +60,7 @@ func Setup(
 	keyAPI keyserverAPI.KeyInternalAPI,
 	extRoomsProvider api.ExtraPublicRoomsProvider,
 ) {
+	rateLimits := newRateLimits(&cfg.RateLimiting)
 	userInteractiveAuth := auth.NewUserInteractive(accountDB.GetAccountByPassword, cfg)
 
 	publicAPIMux.Handle("/versions",
@@ -92,6 +93,9 @@ func Setup(
 	).Methods(http.MethodPost, http.MethodOptions)
 	r0mux.Handle("/join/{roomIDOrAlias}",
 		httputil.MakeAuthAPI(gomatrixserverlib.Join, userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
 			if err != nil {
 				return util.ErrorResponse(err)
@@ -119,6 +123,9 @@ func Setup(
 	).Methods(http.MethodGet, http.MethodOptions)
 	r0mux.Handle("/rooms/{roomID}/join",
 		httputil.MakeAuthAPI(gomatrixserverlib.Join, userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
 			if err != nil {
 				return util.ErrorResponse(err)
@@ -130,6 +137,9 @@ func Setup(
 	).Methods(http.MethodPost, http.MethodOptions)
 	r0mux.Handle("/rooms/{roomID}/leave",
 		httputil.MakeAuthAPI("membership", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
 			if err != nil {
 				return util.ErrorResponse(err)
@@ -150,6 +160,9 @@ func Setup(
 	).Methods(http.MethodPost, http.MethodOptions)
 	r0mux.Handle("/rooms/{roomID}/invite",
 		httputil.MakeAuthAPI("membership", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
 			if err != nil {
 				return util.ErrorResponse(err)
@@ -264,14 +277,23 @@ func Setup(
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	r0mux.Handle("/register", httputil.MakeExternalAPI("register", func(req *http.Request) util.JSONResponse {
+		if r := rateLimits.rateLimit(req); r != nil {
+			return *r
+		}
 		return Register(req, userAPI, accountDB, cfg)
 	})).Methods(http.MethodPost, http.MethodOptions)
 
 	v1mux.Handle("/register", httputil.MakeExternalAPI("register", func(req *http.Request) util.JSONResponse {
+		if r := rateLimits.rateLimit(req); r != nil {
+			return *r
+		}
 		return LegacyRegister(req, userAPI, cfg)
 	})).Methods(http.MethodPost, http.MethodOptions)
 
 	r0mux.Handle("/register/available", httputil.MakeExternalAPI("registerAvailable", func(req *http.Request) util.JSONResponse {
+		if r := rateLimits.rateLimit(req); r != nil {
+			return *r
+		}
 		return RegisterAvailable(req, cfg, accountDB)
 	})).Methods(http.MethodGet, http.MethodOptions)
 
@@ -343,6 +365,9 @@ func Setup(
 
 	r0mux.Handle("/rooms/{roomID}/typing/{userID}",
 		httputil.MakeAuthAPI("rooms_typing", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
 			if err != nil {
 				return util.ErrorResponse(err)
@@ -396,6 +421,9 @@ func Setup(
 
 	r0mux.Handle("/account/whoami",
 		httputil.MakeAuthAPI("whoami", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			return Whoami(req, device)
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
@@ -404,6 +432,9 @@ func Setup(
 
 	r0mux.Handle("/login",
 		httputil.MakeExternalAPI("login", func(req *http.Request) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			return Login(req, accountDB, userAPI, cfg)
 		}),
 	).Methods(http.MethodGet, http.MethodPost, http.MethodOptions)
@@ -458,6 +489,9 @@ func Setup(
 
 	r0mux.Handle("/profile/{userID}/avatar_url",
 		httputil.MakeAuthAPI("profile_avatar_url", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
 			if err != nil {
 				return util.ErrorResponse(err)
@@ -480,6 +514,9 @@ func Setup(
 
 	r0mux.Handle("/profile/{userID}/displayname",
 		httputil.MakeAuthAPI("profile_displayname", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
 			if err != nil {
 				return util.ErrorResponse(err)
@@ -517,6 +554,9 @@ func Setup(
 	// Riot logs get flooded unless this is handled
 	r0mux.Handle("/presence/{userID}/status",
 		httputil.MakeExternalAPI("presence", func(req *http.Request) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			// TODO: Set presence (probably the responsibility of a presence server not clientapi)
 			return util.JSONResponse{
 				Code: http.StatusOK,
@@ -527,6 +567,9 @@ func Setup(
 
 	r0mux.Handle("/voip/turnServer",
 		httputil.MakeAuthAPI("turn_server", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			return RequestTurnServer(req, device, cfg)
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
@@ -593,6 +636,9 @@ func Setup(
 
 	r0mux.Handle("/user_directory/search",
 		httputil.MakeAuthAPI("userdirectory_search", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			postContent := struct {
 				SearchString string `json:"search_term"`
 				Limit        int    `json:"limit"`
@@ -634,6 +680,9 @@ func Setup(
 
 	r0mux.Handle("/rooms/{roomID}/read_markers",
 		httputil.MakeExternalAPI("rooms_read_markers", func(req *http.Request) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			// TODO: return the read_markers.
 			return util.JSONResponse{Code: http.StatusOK, JSON: struct{}{}}
 		}),
@@ -732,6 +781,9 @@ func Setup(
 
 	r0mux.Handle("/capabilities",
 		httputil.MakeAuthAPI("capabilities", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
+			if r := rateLimits.rateLimit(req); r != nil {
+				return *r
+			}
 			return GetCapabilities(req, rsAPI)
 		}),
 	).Methods(http.MethodGet)

clientapi/routing/sendevent.go

@@ -90,27 +90,26 @@ func SendEvent(
 
 	// pass the new event to the roomserver and receive the correct event ID
 	// event ID in case of duplicate transaction is discarded
-	eventID, err := api.SendEvents(
+	if err := api.SendEvents(
 		req.Context(), rsAPI,
 		[]gomatrixserverlib.HeaderedEvent{
 			e.Headered(verRes.RoomVersion),
 		},
 		cfg.Matrix.ServerName,
 		txnAndSessionID,
-	)
-	if err != nil {
+	); err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("SendEvents failed")
 		return jsonerror.InternalServerError()
 	}
 	util.GetLogger(req.Context()).WithFields(logrus.Fields{
-		"event_id":     eventID,
+		"event_id":     e.EventID(),
 		"room_id":      roomID,
 		"room_version": verRes.RoomVersion,
 	}).Info("Sent event to roomserver")
 
 	res := util.JSONResponse{
 		Code: http.StatusOK,
-		JSON: sendEventResponse{eventID},
+		JSON: sendEventResponse{e.EventID()},
 	}
 	// Add response to transactionsCache
 	if txnID != nil {
@@ -158,7 +157,7 @@ func generateSendEvent(
 	}
 
 	var queryRes api.QueryLatestEventsAndStateResponse
-	e, err := eventutil.BuildEvent(req.Context(), &builder, cfg.Matrix, evTime, rsAPI, &queryRes)
+	e, err := eventutil.QueryAndBuildEvent(req.Context(), &builder, cfg.Matrix, evTime, rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return nil, &util.JSONResponse{
 			Code: http.StatusNotFound,

clientapi/threepid/invites.go

@@ -354,12 +354,12 @@ func emit3PIDInviteEvent(
 	}
 
 	queryRes := api.QueryLatestEventsAndStateResponse{}
-	event, err := eventutil.BuildEvent(ctx, builder, cfg.Matrix, evTime, rsAPI, &queryRes)
+	event, err := eventutil.QueryAndBuildEvent(ctx, builder, cfg.Matrix, evTime, rsAPI, &queryRes)
 	if err != nil {
 		return err
 	}
 
-	_, err = api.SendEvents(
+	return api.SendEvents(
 		ctx, rsAPI,
 		[]gomatrixserverlib.HeaderedEvent{
 			(*event).Headered(queryRes.RoomVersion),
@@ -367,5 +367,4 @@ func emit3PIDInviteEvent(
 		cfg.Matrix.ServerName,
 		nil,
 	)
-	return err
 }

cmd/dendrite-demo-libp2p/main.go

@@ -155,7 +155,7 @@ func main() {
 
 	stateAPI := currentstateserver.NewInternalAPI(&base.Base.Cfg.CurrentStateServer, base.Base.KafkaConsumer)
 	rsAPI := roomserver.NewInternalAPI(
-		&base.Base, keyRing, federation,
+		&base.Base, keyRing,
 	)
 	eduInputAPI := eduserver.NewInternalAPI(
 		&base.Base, cache.New(), userAPI,

cmd/dendrite-demo-yggdrasil/main.go

@@ -104,7 +104,7 @@ func main() {
 	keyAPI.SetUserAPI(userAPI)
 
 	rsComponent := roomserver.NewInternalAPI(
-		base, keyRing, federation,
+		base, keyRing,
 	)
 	rsAPI := rsComponent
 

cmd/dendrite-monolith-server/main.go

@@ -81,7 +81,7 @@ func main() {
 	keyRing := serverKeyAPI.KeyRing()
 
 	rsImpl := roomserver.NewInternalAPI(
-		base, keyRing, federation,
+		base, keyRing,
 	)
 	// call functions directly on the impl unless running in HTTP mode
 	rsAPI := rsImpl

cmd/dendrite-room-server/main.go

@@ -23,13 +23,12 @@ func main() {
 	cfg := setup.ParseFlags(false)
 	base := setup.NewBaseDendrite(cfg, "RoomServerAPI", true)
 	defer base.Close() // nolint: errcheck
-	federation := base.CreateFederationClient()
 
 	serverKeyAPI := base.ServerKeyAPIClient()
 	keyRing := serverKeyAPI.KeyRing()
 
 	fsAPI := base.FederationSenderHTTPClient()
-	rsAPI := roomserver.NewInternalAPI(base, keyRing, federation)
+	rsAPI := roomserver.NewInternalAPI(base, keyRing)
 	rsAPI.SetFederationSenderAPI(fsAPI)
 	roomserver.AddInternalRoutes(base.InternalAPIMux, rsAPI)
 

cmd/dendritejs/main.go

@@ -205,7 +205,7 @@ func main() {
 	}
 
 	stateAPI := currentstateserver.NewInternalAPI(&base.Cfg.CurrentStateServer, base.KafkaConsumer)
-	rsAPI := roomserver.NewInternalAPI(base, keyRing, federation)
+	rsAPI := roomserver.NewInternalAPI(base, keyRing)
 	eduInputAPI := eduserver.NewInternalAPI(base, cache.New(), userAPI)
 	asQuery := appservice.NewInternalAPI(
 		base, userAPI, rsAPI,

cmd/generate-config/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 
 	"github.com/matrix-org/dendrite/internal/config"
@@ -8,6 +9,9 @@ import (
 )
 
 func main() {
+	defaultsForCI := flag.Bool("ci", false, "sane defaults for CI testing")
+	flag.Parse()
+
 	cfg := &config.Dendrite{}
 	cfg.Defaults()
 	cfg.Global.TrustedIDServers = []string{
@@ -56,6 +60,11 @@ func main() {
 		},
 	}
 
+	if *defaultsForCI {
+		cfg.ClientAPI.RateLimiting.Enabled = false
+		cfg.FederationSender.DisableTLSValidation = true
+	}
+
 	j, err := yaml.Marshal(cfg)
 	if err != nil {
 		panic(err)

currentstateserver/acls/acls.go

@@ -23,17 +23,25 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/matrix-org/dendrite/currentstateserver/storage"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/sirupsen/logrus"
 )
 
+type ServerACLDatabase interface {
+	// GetKnownRooms returns a list of all rooms we know about.
+	GetKnownRooms(ctx context.Context) ([]string, error)
+	// GetStateEvent returns the state event of a given type for a given room with a given state key
+	// If no event could be found, returns nil
+	// If there was an issue during the retrieval, returns an error
+	GetStateEvent(ctx context.Context, roomID, evType, stateKey string) (*gomatrixserverlib.HeaderedEvent, error)
+}
+
 type ServerACLs struct {
 	acls      map[string]*serverACL // room ID -> ACL
 	aclsMutex sync.RWMutex          // protects the above
 }
 
-func NewServerACLs(db storage.Database) *ServerACLs {
+func NewServerACLs(db ServerACLDatabase) *ServerACLs {
 	ctx := context.TODO()
 	acls := &ServerACLs{
 		acls: make(map[string]*serverACL),

dendrite-config.yaml

@@ -133,6 +133,14 @@ client_api:
     turn_username: ""
     turn_password: ""
 
+  # Settings for rate-limited endpoints. Rate limiting will kick in after the
+  # threshold number of "slots" have been taken by requests from a specific 
+  # host. Each "slot" will be released after the cooloff time in milliseconds.
+  rate_limiting:
+    enabled: true
+    threshold: 5
+    cooloff_ms: 500
+
 # Configuration for the Current State Server.
 current_state_server:
   internal_api:

federationapi/routing/join.go

@@ -95,7 +95,7 @@ func MakeJoin(
 	queryRes := api.QueryLatestEventsAndStateResponse{
 		RoomVersion: verRes.RoomVersion,
 	}
-	event, err := eventutil.BuildEvent(httpReq.Context(), &builder, cfg.Matrix, time.Now(), rsAPI, &queryRes)
+	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &builder, cfg.Matrix, time.Now(), rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,
@@ -266,15 +266,14 @@ func SendJoin(
 	// We are responsible for notifying other servers that the user has joined
 	// the room, so set SendAsServer to cfg.Matrix.ServerName
 	if !alreadyJoined {
-		_, err = api.SendEvents(
+		if err = api.SendEvents(
 			httpReq.Context(), rsAPI,
 			[]gomatrixserverlib.HeaderedEvent{
 				event.Headered(stateAndAuthChainResponse.RoomVersion),
 			},
 			cfg.Matrix.ServerName,
 			nil,
-		)
-		if err != nil {
+		); err != nil {
 			util.GetLogger(httpReq.Context()).WithError(err).Error("SendEvents failed")
 			return jsonerror.InternalServerError()
 		}

federationapi/routing/leave.go

@@ -61,7 +61,7 @@ func MakeLeave(
 	}
 
 	var queryRes api.QueryLatestEventsAndStateResponse
-	event, err := eventutil.BuildEvent(httpReq.Context(), &builder, cfg.Matrix, time.Now(), rsAPI, &queryRes)
+	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &builder, cfg.Matrix, time.Now(), rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,
@@ -247,15 +247,14 @@ func SendLeave(
 	// Send the events to the room server.
 	// We are responsible for notifying other servers that the user has left
 	// the room, so set SendAsServer to cfg.Matrix.ServerName
-	_, err = api.SendEvents(
+	if err = api.SendEvents(
 		httpReq.Context(), rsAPI,
 		[]gomatrixserverlib.HeaderedEvent{
 			event.Headered(verRes.RoomVersion),
 		},
 		cfg.Matrix.ServerName,
 		nil,
-	)
-	if err != nil {
+	); err != nil {
 		util.GetLogger(httpReq.Context()).WithError(err).Error("producer.SendEvents failed")
 		return jsonerror.InternalServerError()
 	}

federationapi/routing/send.go

@@ -382,7 +382,7 @@ func (t *txnReq) processEvent(e gomatrixserverlib.Event, isInboundTxn bool) erro
 	}
 
 	// pass the event to the roomserver
-	_, err := api.SendEvents(
+	return api.SendEvents(
 		t.context, t.rsAPI,
 		[]gomatrixserverlib.HeaderedEvent{
 			e.Headered(stateResp.RoomVersion),
@@ -390,7 +390,6 @@ func (t *txnReq) processEvent(e gomatrixserverlib.Event, isInboundTxn bool) erro
 		api.DoNotSendToOtherServers,
 		nil,
 	)
-	return err
 }
 
 func checkAllowedByState(e gomatrixserverlib.Event, stateEvents []gomatrixserverlib.Event) error {

federationapi/routing/send_test.go

@@ -296,6 +296,30 @@ func (t *testRoomserverAPI) RemoveRoomAlias(
 	return fmt.Errorf("not implemented")
 }
 
+func (t *testRoomserverAPI) QueryCurrentState(ctx context.Context, req *api.QueryCurrentStateRequest, res *api.QueryCurrentStateResponse) error {
+	return nil
+}
+
+func (t *testRoomserverAPI) QueryRoomsForUser(ctx context.Context, req *api.QueryRoomsForUserRequest, res *api.QueryRoomsForUserResponse) error {
+	return fmt.Errorf("not implemented")
+}
+
+func (t *testRoomserverAPI) QueryBulkStateContent(ctx context.Context, req *api.QueryBulkStateContentRequest, res *api.QueryBulkStateContentResponse) error {
+	return fmt.Errorf("not implemented")
+}
+
+func (t *testRoomserverAPI) QuerySharedUsers(ctx context.Context, req *api.QuerySharedUsersRequest, res *api.QuerySharedUsersResponse) error {
+	return fmt.Errorf("not implemented")
+}
+
+func (t *testRoomserverAPI) QueryKnownUsers(ctx context.Context, req *api.QueryKnownUsersRequest, res *api.QueryKnownUsersResponse) error {
+	return fmt.Errorf("not implemented")
+}
+
+func (t *testRoomserverAPI) QueryServerBannedFromRoom(ctx context.Context, req *api.QueryServerBannedFromRoomRequest, res *api.QueryServerBannedFromRoomResponse) error {
+	return nil
+}
+
 type testStateAPI struct {
 }
 

federationapi/routing/threepid.go

@@ -89,7 +89,7 @@ func CreateInvitesFrom3PIDInvites(
 	}
 
 	// Send all the events
-	if _, err := api.SendEvents(req.Context(), rsAPI, evs, cfg.Matrix.ServerName, nil); err != nil {
+	if err := api.SendEvents(req.Context(), rsAPI, evs, cfg.Matrix.ServerName, nil); err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("SendEvents failed")
 		return jsonerror.InternalServerError()
 	}
@@ -172,7 +172,7 @@ func ExchangeThirdPartyInvite(
 	}
 
 	// Send the event to the roomserver
-	if _, err = api.SendEvents(
+	if err = api.SendEvents(
 		httpReq.Context(), rsAPI,
 		[]gomatrixserverlib.HeaderedEvent{
 			signedEvent.Event.Headered(verRes.RoomVersion),

federationapi/routing/version.go

@@ -17,6 +17,7 @@ package routing
 import (
 	"net/http"
 
+	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/util"
 )
 
@@ -31,5 +32,13 @@ type server struct {
 
 // Version returns the server version
 func Version() util.JSONResponse {
-	return util.JSONResponse{Code: http.StatusOK, JSON: &version{server{"dev", "Dendrite"}}}
+	return util.JSONResponse{
+		Code: http.StatusOK,
+		JSON: &version{
+			server{
+				Name:    "Dendrite",
+				Version: internal.VersionString(),
+			},
+		},
+	}
 }

federationsender/api/api.go

@@ -14,9 +14,12 @@ import (
 // implements as proxy calls, with built-in backoff/retries/etc. Errors returned from functions in
 // this interface are of type FederationClientError
 type FederationClient interface {
+	gomatrixserverlib.BackfillClient
+	gomatrixserverlib.FederatedStateClient
 	GetUserDevices(ctx context.Context, s gomatrixserverlib.ServerName, userID string) (res gomatrixserverlib.RespUserDevices, err error)
 	ClaimKeys(ctx context.Context, s gomatrixserverlib.ServerName, oneTimeKeys map[string]map[string]string) (res gomatrixserverlib.RespClaimKeys, err error)
 	QueryKeys(ctx context.Context, s gomatrixserverlib.ServerName, keys map[string][]string) (res gomatrixserverlib.RespQueryKeys, err error)
+	GetEvent(ctx context.Context, s gomatrixserverlib.ServerName, eventID string) (res gomatrixserverlib.Transaction, err error)
 }
 
 // FederationClientError is returned from FederationClient methods in the event of a problem.

federationsender/internal/api.go

@@ -136,3 +136,51 @@ func (a *FederationSenderInternalAPI) QueryKeys(
 	}
 	return ires.(gomatrixserverlib.RespQueryKeys), nil
 }
+
+func (a *FederationSenderInternalAPI) Backfill(
+	ctx context.Context, s gomatrixserverlib.ServerName, roomID string, limit int, eventIDs []string,
+) (res gomatrixserverlib.Transaction, err error) {
+	ires, err := a.doRequest(s, func() (interface{}, error) {
+		return a.federation.Backfill(ctx, s, roomID, limit, eventIDs)
+	})
+	if err != nil {
+		return gomatrixserverlib.Transaction{}, err
+	}
+	return ires.(gomatrixserverlib.Transaction), nil
+}
+
+func (a *FederationSenderInternalAPI) LookupState(
+	ctx context.Context, s gomatrixserverlib.ServerName, roomID, eventID string, roomVersion gomatrixserverlib.RoomVersion,
+) (res gomatrixserverlib.RespState, err error) {
+	ires, err := a.doRequest(s, func() (interface{}, error) {
+		return a.federation.LookupState(ctx, s, roomID, eventID, roomVersion)
+	})
+	if err != nil {
+		return gomatrixserverlib.RespState{}, err
+	}
+	return ires.(gomatrixserverlib.RespState), nil
+}
+
+func (a *FederationSenderInternalAPI) LookupStateIDs(
+	ctx context.Context, s gomatrixserverlib.ServerName, roomID, eventID string,
+) (res gomatrixserverlib.RespStateIDs, err error) {
+	ires, err := a.doRequest(s, func() (interface{}, error) {
+		return a.federation.LookupStateIDs(ctx, s, roomID, eventID)
+	})
+	if err != nil {
+		return gomatrixserverlib.RespStateIDs{}, err
+	}
+	return ires.(gomatrixserverlib.RespStateIDs), nil
+}
+
+func (a *FederationSenderInternalAPI) GetEvent(
+	ctx context.Context, s gomatrixserverlib.ServerName, eventID string,
+) (res gomatrixserverlib.Transaction, err error) {
+	ires, err := a.doRequest(s, func() (interface{}, error) {
+		return a.federation.GetEvent(ctx, s, eventID)
+	})
+	if err != nil {
+		return gomatrixserverlib.Transaction{}, err
+	}
+	return ires.(gomatrixserverlib.Transaction), nil
+}

federationsender/inthttp/client.go

@@ -26,6 +26,10 @@ const (
 	FederationSenderGetUserDevicesPath = "/federationsender/client/getUserDevices"
 	FederationSenderClaimKeysPath      = "/federationsender/client/claimKeys"
 	FederationSenderQueryKeysPath      = "/federationsender/client/queryKeys"
+	FederationSenderBackfillPath       = "/federationsender/client/backfill"
+	FederationSenderLookupStatePath    = "/federationsender/client/lookupState"
+	FederationSenderLookupStateIDsPath = "/federationsender/client/lookupStateIDs"
+	FederationSenderGetEventPath       = "/federationsender/client/getEvent"
 )
 
 // NewFederationSenderClient creates a FederationSenderInternalAPI implemented by talking to a HTTP POST API.
@@ -228,3 +232,129 @@ func (h *httpFederationSenderInternalAPI) QueryKeys(
 	}
 	return *response.Res, nil
 }
+
+type backfill struct {
+	S        gomatrixserverlib.ServerName
+	RoomID   string
+	Limit    int
+	EventIDs []string
+	Res      *gomatrixserverlib.Transaction
+	Err      *api.FederationClientError
+}
+
+func (h *httpFederationSenderInternalAPI) Backfill(
+	ctx context.Context, s gomatrixserverlib.ServerName, roomID string, limit int, eventIDs []string,
+) (gomatrixserverlib.Transaction, error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "Backfill")
+	defer span.Finish()
+
+	request := backfill{
+		S:        s,
+		RoomID:   roomID,
+		Limit:    limit,
+		EventIDs: eventIDs,
+	}
+	var response backfill
+	apiURL := h.federationSenderURL + FederationSenderBackfillPath
+	err := httputil.PostJSON(ctx, span, h.httpClient, apiURL, &request, &response)
+	if err != nil {
+		return gomatrixserverlib.Transaction{}, err
+	}
+	if response.Err != nil {
+		return gomatrixserverlib.Transaction{}, response.Err
+	}
+	return *response.Res, nil
+}
+
+type lookupState struct {
+	S           gomatrixserverlib.ServerName
+	RoomID      string
+	EventID     string
+	RoomVersion gomatrixserverlib.RoomVersion
+	Res         *gomatrixserverlib.RespState
+	Err         *api.FederationClientError
+}
+
+func (h *httpFederationSenderInternalAPI) LookupState(
+	ctx context.Context, s gomatrixserverlib.ServerName, roomID, eventID string, roomVersion gomatrixserverlib.RoomVersion,
+) (gomatrixserverlib.RespState, error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "LookupState")
+	defer span.Finish()
+
+	request := lookupState{
+		S:           s,
+		RoomID:      roomID,
+		EventID:     eventID,
+		RoomVersion: roomVersion,
+	}
+	var response lookupState
+	apiURL := h.federationSenderURL + FederationSenderLookupStatePath
+	err := httputil.PostJSON(ctx, span, h.httpClient, apiURL, &request, &response)
+	if err != nil {
+		return gomatrixserverlib.RespState{}, err
+	}
+	if response.Err != nil {
+		return gomatrixserverlib.RespState{}, response.Err
+	}
+	return *response.Res, nil
+}
+
+type lookupStateIDs struct {
+	S       gomatrixserverlib.ServerName
+	RoomID  string
+	EventID string
+	Res     *gomatrixserverlib.RespStateIDs
+	Err     *api.FederationClientError
+}
+
+func (h *httpFederationSenderInternalAPI) LookupStateIDs(
+	ctx context.Context, s gomatrixserverlib.ServerName, roomID, eventID string,
+) (gomatrixserverlib.RespStateIDs, error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "LookupStateIDs")
+	defer span.Finish()
+
+	request := lookupStateIDs{
+		S:       s,
+		RoomID:  roomID,
+		EventID: eventID,
+	}
+	var response lookupStateIDs
+	apiURL := h.federationSenderURL + FederationSenderLookupStateIDsPath
+	err := httputil.PostJSON(ctx, span, h.httpClient, apiURL, &request, &response)
+	if err != nil {
+		return gomatrixserverlib.RespStateIDs{}, err
+	}
+	if response.Err != nil {
+		return gomatrixserverlib.RespStateIDs{}, response.Err
+	}
+	return *response.Res, nil
+}
+
+type getEvent struct {
+	S       gomatrixserverlib.ServerName
+	EventID string
+	Res     *gomatrixserverlib.Transaction
+	Err     *api.FederationClientError
+}
+
+func (h *httpFederationSenderInternalAPI) GetEvent(
+	ctx context.Context, s gomatrixserverlib.ServerName, eventID string,
+) (gomatrixserverlib.Transaction, error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "GetEvent")
+	defer span.Finish()
+
+	request := getEvent{
+		S:       s,
+		EventID: eventID,
+	}
+	var response getEvent
+	apiURL := h.federationSenderURL + FederationSenderGetEventPath
+	err := httputil.PostJSON(ctx, span, h.httpClient, apiURL, &request, &response)
+	if err != nil {
+		return gomatrixserverlib.Transaction{}, err
+	}
+	if response.Err != nil {
+		return gomatrixserverlib.Transaction{}, response.Err
+	}
+	return *response.Res, nil
+}

federationsender/inthttp/server.go

@@ -175,4 +175,92 @@ func AddRoutes(intAPI api.FederationSenderInternalAPI, internalAPIMux *mux.Route
 			return util.JSONResponse{Code: http.StatusOK, JSON: request}
 		}),
 	)
+	internalAPIMux.Handle(
+		FederationSenderBackfillPath,
+		httputil.MakeInternalAPI("Backfill", func(req *http.Request) util.JSONResponse {
+			var request backfill
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			res, err := intAPI.Backfill(req.Context(), request.S, request.RoomID, request.Limit, request.EventIDs)
+			if err != nil {
+				ferr, ok := err.(*api.FederationClientError)
+				if ok {
+					request.Err = ferr
+				} else {
+					request.Err = &api.FederationClientError{
+						Err: err.Error(),
+					}
+				}
+			}
+			request.Res = &res
+			return util.JSONResponse{Code: http.StatusOK, JSON: request}
+		}),
+	)
+	internalAPIMux.Handle(
+		FederationSenderLookupStatePath,
+		httputil.MakeInternalAPI("LookupState", func(req *http.Request) util.JSONResponse {
+			var request lookupState
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			res, err := intAPI.LookupState(req.Context(), request.S, request.RoomID, request.EventID, request.RoomVersion)
+			if err != nil {
+				ferr, ok := err.(*api.FederationClientError)
+				if ok {
+					request.Err = ferr
+				} else {
+					request.Err = &api.FederationClientError{
+						Err: err.Error(),
+					}
+				}
+			}
+			request.Res = &res
+			return util.JSONResponse{Code: http.StatusOK, JSON: request}
+		}),
+	)
+	internalAPIMux.Handle(
+		FederationSenderLookupStateIDsPath,
+		httputil.MakeInternalAPI("LookupStateIDs", func(req *http.Request) util.JSONResponse {
+			var request lookupStateIDs
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			res, err := intAPI.LookupStateIDs(req.Context(), request.S, request.RoomID, request.EventID)
+			if err != nil {
+				ferr, ok := err.(*api.FederationClientError)
+				if ok {
+					request.Err = ferr
+				} else {
+					request.Err = &api.FederationClientError{
+						Err: err.Error(),
+					}
+				}
+			}
+			request.Res = &res
+			return util.JSONResponse{Code: http.StatusOK, JSON: request}
+		}),
+	)
+	internalAPIMux.Handle(
+		FederationSenderGetEventPath,
+		httputil.MakeInternalAPI("GetEvent", func(req *http.Request) util.JSONResponse {
+			var request getEvent
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			res, err := intAPI.GetEvent(req.Context(), request.S, request.EventID)
+			if err != nil {
+				ferr, ok := err.(*api.FederationClientError)
+				if ok {
+					request.Err = ferr
+				} else {
+					request.Err = &api.FederationClientError{
+						Err: err.Error(),
+					}
+				}
+			}
+			request.Res = &res
+			return util.JSONResponse{Code: http.StatusOK, JSON: request}
+		}),
+	)
 }

go.mod

@@ -21,7 +21,7 @@ require (
 	github.com/matrix-org/go-http-js-libp2p v0.0.0-20200518170932-783164aeeda4
 	github.com/matrix-org/go-sqlite3-js v0.0.0-20200522092705-bc8506ccbcf3
 	github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd
-	github.com/matrix-org/gomatrixserverlib v0.0.0-20200817100842-9d02141812f2
+	github.com/matrix-org/gomatrixserverlib v0.0.0-20200902135805-f7a5b5e89750
 	github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91
 	github.com/matrix-org/util v0.0.0-20200807132607-55161520e1d4
 	github.com/mattn/go-sqlite3 v1.14.2

go.sum

@@ -567,8 +567,8 @@ github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26 h1:Hr3zjRsq2bh
 github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26/go.mod h1:3fxX6gUjWyI/2Bt7J1OLhpCzOfO/bB3AiX0cJtEKud0=
 github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd h1:xVrqJK3xHREMNjwjljkAUaadalWc0rRbmVuQatzmgwg=
 github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd/go.mod h1:/gBX06Kw0exX1HrwmoBibFA98yBk/jxKpGVeyQbff+s=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20200817100842-9d02141812f2 h1:9wKwfd5KDcXuqZ7/kAaYe0QM4DGM+2awjjvXQtrDa6k=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20200817100842-9d02141812f2/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20200902135805-f7a5b5e89750 h1:k5vsLfpylXHOXgN51N0QNbak9i+4bT33Puk/ZJgcdDw=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20200902135805-f7a5b5e89750/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
 github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91 h1:HJ6U3S3ljJqNffYMcIeAncp5qT/i+ZMiJ2JC2F0aXP4=
 github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91/go.mod h1:sjyPyRxKM5uw1nD2cJ6O2OxI6GOqyVBfNXqKjBZTBZE=
 github.com/matrix-org/util v0.0.0-20190711121626-527ce5ddefc7 h1:ntrLa/8xVzeSs8vHFHK25k0C+NV74sYMJnNSg5NoSRo=

internal/config/config_clientapi.go

@@ -34,6 +34,9 @@ type ClientAPI struct {
 
 	// TURN options
 	TURN TURN `yaml:"turn"`
+
+	// Rate-limiting options
+	RateLimiting RateLimiting `yaml:"rate_limiting"`
 }
 
 func (c *ClientAPI) Defaults() {
@@ -47,6 +50,7 @@ func (c *ClientAPI) Defaults() {
 	c.RecaptchaBypassSecret = ""
 	c.RecaptchaSiteVerifyAPI = ""
 	c.RegistrationDisabled = false
+	c.RateLimiting.Defaults()
 }
 
 func (c *ClientAPI) Verify(configErrs *ConfigErrors, isMonolith bool) {
@@ -61,6 +65,7 @@ func (c *ClientAPI) Verify(configErrs *ConfigErrors, isMonolith bool) {
 		checkNotEmpty(configErrs, "client_api.recaptcha_siteverify_api", string(c.RecaptchaSiteVerifyAPI))
 	}
 	c.TURN.Verify(configErrs)
+	c.RateLimiting.Verify(configErrs)
 }
 
 type TURN struct {
@@ -90,3 +95,29 @@ func (c *TURN) Verify(configErrs *ConfigErrors) {
 		}
 	}
 }
+
+type RateLimiting struct {
+	// Is rate limiting enabled or disabled?
+	Enabled bool `yaml:"enabled"`
+
+	// How many "slots" a user can occupy sending requests to a rate-limited
+	// endpoint before we apply rate-limiting
+	Threshold int64 `yaml:"threshold"`
+
+	// The cooloff period in milliseconds after a request before the "slot"
+	// is freed again
+	CooloffMS int64 `yaml:"cooloff_ms"`
+}
+
+func (r *RateLimiting) Verify(configErrs *ConfigErrors) {
+	if r.Enabled {
+		checkPositive(configErrs, "client_api.rate_limiting.threshold", r.Threshold)
+		checkPositive(configErrs, "client_api.rate_limiting.cooloff_ms", r.CooloffMS)
+	}
+}
+
+func (r *RateLimiting) Defaults() {
+	r.Enabled = true
+	r.Threshold = 5
+	r.CooloffMS = 500
+}

internal/eventutil/events.go

@@ -30,13 +30,13 @@ import (
 // doesn't exist
 var ErrRoomNoExists = errors.New("Room does not exist")
 
-// BuildEvent builds a Matrix event using the event builder and roomserver query
+// QueryAndBuildEvent builds a Matrix event using the event builder and roomserver query
 // API client provided. If also fills roomserver query API response (if provided)
 // in case the function calling FillBuilder needs to use it.
 // Returns ErrRoomNoExists if the state of the room could not be retrieved because
 // the room doesn't exist
 // Returns an error if something else went wrong
-func BuildEvent(
+func QueryAndBuildEvent(
 	ctx context.Context,
 	builder *gomatrixserverlib.EventBuilder, cfg *config.Global, evTime time.Time,
 	rsAPI api.RoomserverInternalAPI, queryRes *api.QueryLatestEventsAndStateResponse,
@@ -45,11 +45,25 @@ func BuildEvent(
 		queryRes = &api.QueryLatestEventsAndStateResponse{}
 	}
 
-	ver, err := AddPrevEventsToEvent(ctx, builder, rsAPI, queryRes)
+	eventsNeeded, err := queryRequiredEventsForBuilder(ctx, builder, rsAPI, queryRes)
 	if err != nil {
 		// This can pass through a ErrRoomNoExists to the caller
 		return nil, err
 	}
+	return BuildEvent(ctx, builder, cfg, 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, evTime time.Time,
+	eventsNeeded *gomatrixserverlib.StateNeeded, queryRes *api.QueryLatestEventsAndStateResponse,
+) (*gomatrixserverlib.HeaderedEvent, error) {
+	err := addPrevEventsToEvent(builder, eventsNeeded, queryRes)
+	if err != nil {
+		return nil, err
+	}
 
 	event, err := builder.Build(
 		evTime, cfg.ServerName, cfg.KeyID,
@@ -59,23 +73,23 @@ func BuildEvent(
 		return nil, err
 	}
 
-	h := event.Headered(ver)
+	h := event.Headered(queryRes.RoomVersion)
 	return &h, nil
 }
 
-// AddPrevEventsToEvent fills out the prev_events and auth_events fields in builder
-func AddPrevEventsToEvent(
+// queryRequiredEventsForBuilder queries the roomserver for auth/prev events needed for this builder.
+func queryRequiredEventsForBuilder(
 	ctx context.Context,
 	builder *gomatrixserverlib.EventBuilder,
 	rsAPI api.RoomserverInternalAPI, queryRes *api.QueryLatestEventsAndStateResponse,
-) (gomatrixserverlib.RoomVersion, error) {
+) (*gomatrixserverlib.StateNeeded, error) {
 	eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(builder)
 	if err != nil {
-		return "", fmt.Errorf("gomatrixserverlib.StateNeededForEventBuilder: %w", err)
+		return nil, fmt.Errorf("gomatrixserverlib.StateNeededForEventBuilder: %w", err)
 	}
 
 	if len(eventsNeeded.Tuples()) == 0 {
-		return "", errors.New("expecting state tuples for event builder, got none")
+		return nil, errors.New("expecting state tuples for event builder, got none")
 	}
 
 	// Ask the roomserver for information about this room
@@ -83,17 +97,22 @@ func AddPrevEventsToEvent(
 		RoomID:       builder.RoomID,
 		StateToFetch: eventsNeeded.Tuples(),
 	}
-	if err = rsAPI.QueryLatestEventsAndState(ctx, &queryReq, queryRes); err != nil {
-		return "", fmt.Errorf("rsAPI.QueryLatestEventsAndState: %w", err)
-	}
+	return &eventsNeeded, rsAPI.QueryLatestEventsAndState(ctx, &queryReq, queryRes)
+}
 
+// addPrevEventsToEvent fills out the prev_events and auth_events fields in builder
+func addPrevEventsToEvent(
+	builder *gomatrixserverlib.EventBuilder,
+	eventsNeeded *gomatrixserverlib.StateNeeded,
+	queryRes *api.QueryLatestEventsAndStateResponse,
+) error {
 	if !queryRes.RoomExists {
-		return "", ErrRoomNoExists
+		return ErrRoomNoExists
 	}
 
 	eventFormat, err := queryRes.RoomVersion.EventFormat()
 	if err != nil {
-		return "", fmt.Errorf("queryRes.RoomVersion.EventFormat: %w", err)
+		return fmt.Errorf("queryRes.RoomVersion.EventFormat: %w", err)
 	}
 
 	builder.Depth = queryRes.Depth
@@ -103,13 +122,13 @@ func AddPrevEventsToEvent(
 	for i := range queryRes.StateEvents {
 		err = authEvents.AddEvent(&queryRes.StateEvents[i].Event)
 		if err != nil {
-			return "", fmt.Errorf("authEvents.AddEvent: %w", err)
+			return fmt.Errorf("authEvents.AddEvent: %w", err)
 		}
 	}
 
 	refs, err := eventsNeeded.AuthEventReferences(&authEvents)
 	if err != nil {
-		return "", fmt.Errorf("eventsNeeded.AuthEventReferences: %w", err)
+		return fmt.Errorf("eventsNeeded.AuthEventReferences: %w", err)
 	}
 
 	truncAuth, truncPrev := truncateAuthAndPrevEvents(refs, queryRes.LatestEvents)
@@ -129,7 +148,7 @@ func AddPrevEventsToEvent(
 		builder.PrevEvents = v2PrevRefs
 	}
 
-	return queryRes.RoomVersion, nil
+	return nil
 }
 
 // truncateAuthAndPrevEvents limits the number of events we add into

internal/setup/base.go

@@ -100,6 +100,8 @@ func NewBaseDendrite(cfg *config.Dendrite, componentName string, useHTTPAPIs boo
 	internal.SetupHookLogging(cfg.Logging, componentName)
 	internal.SetupPprof()
 
+	logrus.Infof("Dendrite version %s", internal.VersionString())
+
 	closer, err := cfg.SetupTracing("Dendrite" + componentName)
 	if err != nil {
 		logrus.WithError(err).Panicf("failed to start opentracing")

internal/version.go

@@ -0,0 +1,26 @@
+package internal
+
+import "fmt"
+
+// -ldflags "-X github.com/matrix-org/dendrite/internal.branch=master"
+var branch string
+
+// -ldflags "-X github.com/matrix-org/dendrite/internal.build=alpha"
+var build string
+
+const (
+	VersionMajor = 0
+	VersionMinor = 0
+	VersionPatch = 0
+)
+
+func VersionString() string {
+	version := fmt.Sprintf("%d.%d.%d", VersionMajor, VersionMinor, VersionPatch)
+	if branch != "" {
+		version += fmt.Sprintf("-%s", branch)
+	}
+	if build != "" {
+		version += fmt.Sprintf("+%s", build)
+	}
+	return version
+}

roomserver/acls/acls.go

@@ -0,0 +1,164 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package acls
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net"
+	"regexp"
+	"strings"
+	"sync"
+
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
+)
+
+type ServerACLDatabase interface {
+	// GetKnownRooms returns a list of all rooms we know about.
+	GetKnownRooms(ctx context.Context) ([]string, error)
+	// GetStateEvent returns the state event of a given type for a given room with a given state key
+	// If no event could be found, returns nil
+	// If there was an issue during the retrieval, returns an error
+	GetStateEvent(ctx context.Context, roomID, evType, stateKey string) (*gomatrixserverlib.HeaderedEvent, error)
+}
+
+type ServerACLs struct {
+	acls      map[string]*serverACL // room ID -> ACL
+	aclsMutex sync.RWMutex          // protects the above
+}
+
+func NewServerACLs(db ServerACLDatabase) *ServerACLs {
+	ctx := context.TODO()
+	acls := &ServerACLs{
+		acls: make(map[string]*serverACL),
+	}
+	// Look up all of the rooms that the current state server knows about.
+	rooms, err := db.GetKnownRooms(ctx)
+	if err != nil {
+		logrus.WithError(err).Fatalf("Failed to get known rooms")
+	}
+	// For each room, let's see if we have a server ACL state event. If we
+	// do then we'll process it into memory so that we have the regexes to
+	// hand.
+	for _, room := range rooms {
+		state, err := db.GetStateEvent(ctx, room, "m.room.server_acl", "")
+		if err != nil {
+			logrus.WithError(err).Errorf("Failed to get server ACLs for room %q", room)
+			continue
+		}
+		if state != nil {
+			acls.OnServerACLUpdate(&state.Event)
+		}
+	}
+	return acls
+}
+
+type ServerACL struct {
+	Allowed         []string `json:"allow"`
+	Denied          []string `json:"deny"`
+	AllowIPLiterals bool     `json:"allow_ip_literals"`
+}
+
+type serverACL struct {
+	ServerACL
+	allowedRegexes []*regexp.Regexp
+	deniedRegexes  []*regexp.Regexp
+}
+
+func compileACLRegex(orig string) (*regexp.Regexp, error) {
+	escaped := regexp.QuoteMeta(orig)
+	escaped = strings.Replace(escaped, "\\?", ".", -1)
+	escaped = strings.Replace(escaped, "\\*", ".*", -1)
+	return regexp.Compile(escaped)
+}
+
+func (s *ServerACLs) OnServerACLUpdate(state *gomatrixserverlib.Event) {
+	acls := &serverACL{}
+	if err := json.Unmarshal(state.Content(), &acls.ServerACL); err != nil {
+		logrus.WithError(err).Errorf("Failed to unmarshal state content for server ACLs")
+		return
+	}
+	// The spec calls only for * (zero or more chars) and ? (exactly one char)
+	// to be supported as wildcard components, so we will escape all of the regex
+	// special characters and then replace * and ? with their regex counterparts.
+	// https://matrix.org/docs/spec/client_server/r0.6.1#m-room-server-acl
+	for _, orig := range acls.Allowed {
+		if expr, err := compileACLRegex(orig); err != nil {
+			logrus.WithError(err).Errorf("Failed to compile allowed regex")
+		} else {
+			acls.allowedRegexes = append(acls.allowedRegexes, expr)
+		}
+	}
+	for _, orig := range acls.Denied {
+		if expr, err := compileACLRegex(orig); err != nil {
+			logrus.WithError(err).Errorf("Failed to compile denied regex")
+		} else {
+			acls.deniedRegexes = append(acls.deniedRegexes, expr)
+		}
+	}
+	logrus.WithFields(logrus.Fields{
+		"allow_ip_literals": acls.AllowIPLiterals,
+		"num_allowed":       len(acls.allowedRegexes),
+		"num_denied":        len(acls.deniedRegexes),
+	}).Debugf("Updating server ACLs for %q", state.RoomID())
+	s.aclsMutex.Lock()
+	defer s.aclsMutex.Unlock()
+	s.acls[state.RoomID()] = acls
+}
+
+func (s *ServerACLs) IsServerBannedFromRoom(serverName gomatrixserverlib.ServerName, roomID string) bool {
+	s.aclsMutex.RLock()
+	// First of all check if we have an ACL for this room. If we don't then
+	// no servers are banned from the room.
+	acls, ok := s.acls[roomID]
+	if !ok {
+		s.aclsMutex.RUnlock()
+		return false
+	}
+	s.aclsMutex.RUnlock()
+	// Split the host and port apart. This is because the spec calls on us to
+	// validate the hostname only in cases where the port is also present.
+	if serverNameOnly, _, err := net.SplitHostPort(string(serverName)); err == nil {
+		serverName = gomatrixserverlib.ServerName(serverNameOnly)
+	}
+	// Check if the hostname is an IPv4 or IPv6 literal. We cheat here by adding
+	// a /0 prefix length just to trick ParseCIDR into working. If we find that
+	// the server is an IP literal and we don't allow those then stop straight
+	// away.
+	if _, _, err := net.ParseCIDR(fmt.Sprintf("%s/0", serverName)); err == nil {
+		if !acls.AllowIPLiterals {
+			return true
+		}
+	}
+	// Check if the hostname matches one of the denied regexes. If it does then
+	// the server is banned from the room.
+	for _, expr := range acls.deniedRegexes {
+		if expr.MatchString(string(serverName)) {
+			return true
+		}
+	}
+	// Check if the hostname matches one of the allowed regexes. If it does then
+	// the server is NOT banned from the room.
+	for _, expr := range acls.allowedRegexes {
+		if expr.MatchString(string(serverName)) {
+			return false
+		}
+	}
+	// If we've got to this point then we haven't matched any regexes or an IP
+	// hostname if disallowed. The spec calls for default-deny here.
+	return true
+}

roomserver/acls/acls_test.go

@@ -0,0 +1,105 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package acls
+
+import (
+	"regexp"
+	"testing"
+)
+
+func TestOpenACLsWithBlacklist(t *testing.T) {
+	roomID := "!test:test.com"
+	allowRegex, err := compileACLRegex("*")
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	denyRegex, err := compileACLRegex("foo.com")
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+
+	acls := ServerACLs{
+		acls: make(map[string]*serverACL),
+	}
+
+	acls.acls[roomID] = &serverACL{
+		ServerACL: ServerACL{
+			AllowIPLiterals: true,
+		},
+		allowedRegexes: []*regexp.Regexp{allowRegex},
+		deniedRegexes:  []*regexp.Regexp{denyRegex},
+	}
+
+	if acls.IsServerBannedFromRoom("1.2.3.4", roomID) {
+		t.Fatal("Expected 1.2.3.4 to be allowed but wasn't")
+	}
+	if acls.IsServerBannedFromRoom("1.2.3.4:2345", roomID) {
+		t.Fatal("Expected 1.2.3.4:2345 to be allowed but wasn't")
+	}
+	if !acls.IsServerBannedFromRoom("foo.com", roomID) {
+		t.Fatal("Expected foo.com to be banned but wasn't")
+	}
+	if !acls.IsServerBannedFromRoom("foo.com:3456", roomID) {
+		t.Fatal("Expected foo.com:3456 to be banned but wasn't")
+	}
+	if acls.IsServerBannedFromRoom("bar.com", roomID) {
+		t.Fatal("Expected bar.com to be allowed but wasn't")
+	}
+	if acls.IsServerBannedFromRoom("bar.com:4567", roomID) {
+		t.Fatal("Expected bar.com:4567 to be allowed but wasn't")
+	}
+}
+
+func TestDefaultACLsWithWhitelist(t *testing.T) {
+	roomID := "!test:test.com"
+	allowRegex, err := compileACLRegex("foo.com")
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+
+	acls := ServerACLs{
+		acls: make(map[string]*serverACL),
+	}
+
+	acls.acls[roomID] = &serverACL{
+		ServerACL: ServerACL{
+			AllowIPLiterals: false,
+		},
+		allowedRegexes: []*regexp.Regexp{allowRegex},
+		deniedRegexes:  []*regexp.Regexp{},
+	}
+
+	if !acls.IsServerBannedFromRoom("1.2.3.4", roomID) {
+		t.Fatal("Expected 1.2.3.4 to be banned but wasn't")
+	}
+	if !acls.IsServerBannedFromRoom("1.2.3.4:2345", roomID) {
+		t.Fatal("Expected 1.2.3.4:2345 to be banned but wasn't")
+	}
+	if acls.IsServerBannedFromRoom("foo.com", roomID) {
+		t.Fatal("Expected foo.com to be allowed but wasn't")
+	}
+	if acls.IsServerBannedFromRoom("foo.com:3456", roomID) {
+		t.Fatal("Expected foo.com:3456 to be allowed but wasn't")
+	}
+	if !acls.IsServerBannedFromRoom("bar.com", roomID) {
+		t.Fatal("Expected bar.com to be allowed but wasn't")
+	}
+	if !acls.IsServerBannedFromRoom("baz.com", roomID) {
+		t.Fatal("Expected baz.com to be allowed but wasn't")
+	}
+	if !acls.IsServerBannedFromRoom("qux.com:4567", roomID) {
+		t.Fatal("Expected qux.com:4567 to be allowed but wasn't")
+	}
+}

roomserver/api/api.go

@@ -112,6 +112,20 @@ type RoomserverInternalAPI interface {
 		response *QueryStateAndAuthChainResponse,
 	) error
 
+	// QueryCurrentState retrieves the requested state events. If state events are not found, they will be missing from
+	// the response.
+	QueryCurrentState(ctx context.Context, req *QueryCurrentStateRequest, res *QueryCurrentStateResponse) error
+	// QueryRoomsForUser retrieves a list of room IDs matching the given query.
+	QueryRoomsForUser(ctx context.Context, req *QueryRoomsForUserRequest, res *QueryRoomsForUserResponse) error
+	// QueryBulkStateContent does a bulk query for state event content in the given rooms.
+	QueryBulkStateContent(ctx context.Context, req *QueryBulkStateContentRequest, res *QueryBulkStateContentResponse) error
+	// QuerySharedUsers returns a list of users who share at least 1 room in common with the given user.
+	QuerySharedUsers(ctx context.Context, req *QuerySharedUsersRequest, res *QuerySharedUsersResponse) error
+	// QueryKnownUsers returns a list of users that we know about from our joined rooms.
+	QueryKnownUsers(ctx context.Context, req *QueryKnownUsersRequest, res *QueryKnownUsersResponse) error
+	// QueryServerBannedFromRoom returns whether a server is banned from a room by server ACLs.
+	QueryServerBannedFromRoom(ctx context.Context, req *QueryServerBannedFromRoomRequest, res *QueryServerBannedFromRoomResponse) error
+
 	// Query a given amount (or less) of events prior to a given set of events.
 	PerformBackfill(
 		ctx context.Context,

roomserver/api/api_trace.go

@@ -245,6 +245,47 @@ func (t *RoomserverInternalAPITrace) RemoveRoomAlias(
 	return err
 }
 
+func (t *RoomserverInternalAPITrace) QueryCurrentState(ctx context.Context, req *QueryCurrentStateRequest, res *QueryCurrentStateResponse) error {
+	err := t.Impl.QueryCurrentState(ctx, req, res)
+	util.GetLogger(ctx).WithError(err).Infof("QueryCurrentState req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
+// QueryRoomsForUser retrieves a list of room IDs matching the given query.
+func (t *RoomserverInternalAPITrace) QueryRoomsForUser(ctx context.Context, req *QueryRoomsForUserRequest, res *QueryRoomsForUserResponse) error {
+	err := t.Impl.QueryRoomsForUser(ctx, req, res)
+	util.GetLogger(ctx).WithError(err).Infof("QueryRoomsForUser req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
+// QueryBulkStateContent does a bulk query for state event content in the given rooms.
+func (t *RoomserverInternalAPITrace) QueryBulkStateContent(ctx context.Context, req *QueryBulkStateContentRequest, res *QueryBulkStateContentResponse) error {
+	err := t.Impl.QueryBulkStateContent(ctx, req, res)
+	util.GetLogger(ctx).WithError(err).Infof("QueryBulkStateContent req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
+// QuerySharedUsers returns a list of users who share at least 1 room in common with the given user.
+func (t *RoomserverInternalAPITrace) QuerySharedUsers(ctx context.Context, req *QuerySharedUsersRequest, res *QuerySharedUsersResponse) error {
+	err := t.Impl.QuerySharedUsers(ctx, req, res)
+	util.GetLogger(ctx).WithError(err).Infof("QuerySharedUsers req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
+// QueryKnownUsers returns a list of users that we know about from our joined rooms.
+func (t *RoomserverInternalAPITrace) QueryKnownUsers(ctx context.Context, req *QueryKnownUsersRequest, res *QueryKnownUsersResponse) error {
+	err := t.Impl.QueryKnownUsers(ctx, req, res)
+	util.GetLogger(ctx).WithError(err).Infof("QueryKnownUsers req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
+// QueryServerBannedFromRoom returns whether a server is banned from a room by server ACLs.
+func (t *RoomserverInternalAPITrace) QueryServerBannedFromRoom(ctx context.Context, req *QueryServerBannedFromRoomRequest, res *QueryServerBannedFromRoomResponse) error {
+	err := t.Impl.QueryServerBannedFromRoom(ctx, req, res)
+	util.GetLogger(ctx).WithError(err).Infof("QueryServerBannedFromRoom req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
 func js(thing interface{}) string {
 	b, err := json.Marshal(thing)
 	if err != nil {

roomserver/api/input.go

@@ -83,5 +83,4 @@ type InputRoomEventsRequest struct {
 
 // InputRoomEventsResponse is a response to InputRoomEvents
 type InputRoomEventsResponse struct {
-	EventID string `json:"event_id"`
 }

roomserver/api/query.go

@@ -17,6 +17,11 @@
 package api
 
 import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
@@ -225,3 +230,102 @@ type QueryPublishedRoomsResponse struct {
 	// The list of published rooms.
 	RoomIDs []string
 }
+
+type QuerySharedUsersRequest struct {
+	UserID         string
+	ExcludeRoomIDs []string
+	IncludeRoomIDs []string
+}
+
+type QuerySharedUsersResponse struct {
+	UserIDsToCount map[string]int
+}
+
+type QueryRoomsForUserRequest struct {
+	UserID string
+	// The desired membership of the user. If this is the empty string then no rooms are returned.
+	WantMembership string
+}
+
+type QueryRoomsForUserResponse struct {
+	RoomIDs []string
+}
+
+type QueryBulkStateContentRequest struct {
+	// Returns state events in these rooms
+	RoomIDs []string
+	// If true, treats the '*' StateKey as "all state events of this type" rather than a literal value of '*'
+	AllowWildcards bool
+	// The state events to return. Only a small subset of tuples are allowed in this request as only certain events
+	// have their content fields extracted. Specifically, the tuple Type must be one of:
+	//   m.room.avatar
+	//   m.room.create
+	//   m.room.canonical_alias
+	//   m.room.guest_access
+	//   m.room.history_visibility
+	//   m.room.join_rules
+	//   m.room.member
+	//   m.room.name
+	//   m.room.topic
+	// Any other tuple type will result in the query failing.
+	StateTuples []gomatrixserverlib.StateKeyTuple
+}
+type QueryBulkStateContentResponse struct {
+	// map of room ID -> tuple -> content_value
+	Rooms map[string]map[gomatrixserverlib.StateKeyTuple]string
+}
+
+type QueryCurrentStateRequest struct {
+	RoomID      string
+	StateTuples []gomatrixserverlib.StateKeyTuple
+}
+
+type QueryCurrentStateResponse struct {
+	StateEvents map[gomatrixserverlib.StateKeyTuple]*gomatrixserverlib.HeaderedEvent
+}
+
+type QueryKnownUsersRequest struct {
+	UserID       string `json:"user_id"`
+	SearchString string `json:"search_string"`
+	Limit        int    `json:"limit"`
+}
+
+type QueryKnownUsersResponse struct {
+	Users []authtypes.FullyQualifiedProfile `json:"profiles"`
+}
+
+type QueryServerBannedFromRoomRequest struct {
+	ServerName gomatrixserverlib.ServerName `json:"server_name"`
+	RoomID     string                       `json:"room_id"`
+}
+
+type QueryServerBannedFromRoomResponse struct {
+	Banned bool `json:"banned"`
+}
+
+// MarshalJSON stringifies the StateKeyTuple keys so they can be sent over the wire in HTTP API mode.
+func (r *QueryCurrentStateResponse) MarshalJSON() ([]byte, error) {
+	se := make(map[string]*gomatrixserverlib.HeaderedEvent, len(r.StateEvents))
+	for k, v := range r.StateEvents {
+		// use 0x1F (unit separator) as the delimiter between type/state key,
+		se[fmt.Sprintf("%s\x1F%s", k.EventType, k.StateKey)] = v
+	}
+	return json.Marshal(se)
+}
+
+func (r *QueryCurrentStateResponse) UnmarshalJSON(data []byte) error {
+	res := make(map[string]*gomatrixserverlib.HeaderedEvent)
+	err := json.Unmarshal(data, &res)
+	if err != nil {
+		return err
+	}
+	r.StateEvents = make(map[gomatrixserverlib.StateKeyTuple]*gomatrixserverlib.HeaderedEvent, len(res))
+	for k, v := range res {
+		fields := strings.Split(k, "\x1F")
+		r.StateEvents[gomatrixserverlib.StateKeyTuple{
+			EventType: fields[0],
+			StateKey:  fields[1],
+		}] = v
+	}
+	return nil
+}

roomserver/api/wrapper.go

@@ -26,7 +26,7 @@ import (
 func SendEvents(
 	ctx context.Context, rsAPI RoomserverInternalAPI, events []gomatrixserverlib.HeaderedEvent,
 	sendAsServer gomatrixserverlib.ServerName, txnID *TransactionID,
-) (string, error) {
+) error {
 	ires := make([]InputRoomEvent, len(events))
 	for i, event := range events {
 		ires[i] = InputRoomEvent{
@@ -77,19 +77,16 @@ func SendEventWithState(
 		StateEventIDs: stateEventIDs,
 	})
 
-	_, err = SendInputRoomEvents(ctx, rsAPI, ires)
-	return err
+	return SendInputRoomEvents(ctx, rsAPI, ires)
 }
 
 // SendInputRoomEvents to the roomserver.
 func SendInputRoomEvents(
 	ctx context.Context, rsAPI RoomserverInternalAPI, ires []InputRoomEvent,
-) (eventID string, err error) {
+) error {
 	request := InputRoomEventsRequest{InputRoomEvents: ires}
 	var response InputRoomEventsResponse
-	err = rsAPI.InputRoomEvents(ctx, &request, &response)
-	eventID = response.EventID
-	return
+	return rsAPI.InputRoomEvents(ctx, &request, &response)
 }
 
 // SendInvite event to the roomserver.
@@ -136,3 +133,102 @@ func GetEvent(ctx context.Context, rsAPI RoomserverInternalAPI, eventID string)
 	}
 	return &res.Events[0]
 }
+
+// GetStateEvent returns the current state event in the room or nil.
+func GetStateEvent(ctx context.Context, rsAPI RoomserverInternalAPI, roomID string, tuple gomatrixserverlib.StateKeyTuple) *gomatrixserverlib.HeaderedEvent {
+	var res QueryCurrentStateResponse
+	err := rsAPI.QueryCurrentState(ctx, &QueryCurrentStateRequest{
+		RoomID:      roomID,
+		StateTuples: []gomatrixserverlib.StateKeyTuple{tuple},
+	}, &res)
+	if err != nil {
+		util.GetLogger(ctx).WithError(err).Error("Failed to QueryCurrentState")
+		return nil
+	}
+	ev, ok := res.StateEvents[tuple]
+	if ok {
+		return ev
+	}
+	return nil
+}
+
+// IsServerBannedFromRoom returns whether the server is banned from a room by server ACLs.
+func IsServerBannedFromRoom(ctx context.Context, rsAPI RoomserverInternalAPI, roomID string, serverName gomatrixserverlib.ServerName) bool {
+	req := &QueryServerBannedFromRoomRequest{
+		ServerName: serverName,
+		RoomID:     roomID,
+	}
+	res := &QueryServerBannedFromRoomResponse{}
+	if err := rsAPI.QueryServerBannedFromRoom(ctx, req, res); err != nil {
+		util.GetLogger(ctx).WithError(err).Error("Failed to QueryServerBannedFromRoom")
+		return true
+	}
+	return res.Banned
+}
+
+// PopulatePublicRooms extracts PublicRoom information for all the provided room IDs. The IDs are not checked to see if they are visible in the
+// published room directory.
+// due to lots of switches
+// nolint:gocyclo
+func PopulatePublicRooms(ctx context.Context, roomIDs []string, rsAPI RoomserverInternalAPI) ([]gomatrixserverlib.PublicRoom, error) {
+	avatarTuple := gomatrixserverlib.StateKeyTuple{EventType: "m.room.avatar", StateKey: ""}
+	nameTuple := gomatrixserverlib.StateKeyTuple{EventType: "m.room.name", StateKey: ""}
+	canonicalTuple := gomatrixserverlib.StateKeyTuple{EventType: gomatrixserverlib.MRoomCanonicalAlias, StateKey: ""}
+	topicTuple := gomatrixserverlib.StateKeyTuple{EventType: "m.room.topic", StateKey: ""}
+	guestTuple := gomatrixserverlib.StateKeyTuple{EventType: "m.room.guest_access", StateKey: ""}
+	visibilityTuple := gomatrixserverlib.StateKeyTuple{EventType: gomatrixserverlib.MRoomHistoryVisibility, StateKey: ""}
+	joinRuleTuple := gomatrixserverlib.StateKeyTuple{EventType: gomatrixserverlib.MRoomJoinRules, StateKey: ""}
+
+	var stateRes QueryBulkStateContentResponse
+	err := rsAPI.QueryBulkStateContent(ctx, &QueryBulkStateContentRequest{
+		RoomIDs:        roomIDs,
+		AllowWildcards: true,
+		StateTuples: []gomatrixserverlib.StateKeyTuple{
+			nameTuple, canonicalTuple, topicTuple, guestTuple, visibilityTuple, joinRuleTuple, avatarTuple,
+			{EventType: gomatrixserverlib.MRoomMember, StateKey: "*"},
+		},
+	}, &stateRes)
+	if err != nil {
+		util.GetLogger(ctx).WithError(err).Error("QueryBulkStateContent failed")
+		return nil, err
+	}
+	chunk := make([]gomatrixserverlib.PublicRoom, len(roomIDs))
+	i := 0
+	for roomID, data := range stateRes.Rooms {
+		pub := gomatrixserverlib.PublicRoom{
+			RoomID: roomID,
+		}
+		joinCount := 0
+		var joinRule, guestAccess string
+		for tuple, contentVal := range data {
+			if tuple.EventType == gomatrixserverlib.MRoomMember && contentVal == "join" {
+				joinCount++
+				continue
+			}
+			switch tuple {
+			case avatarTuple:
+				pub.AvatarURL = contentVal
+			case nameTuple:
+				pub.Name = contentVal
+			case topicTuple:
+				pub.Topic = contentVal
+			case canonicalTuple:
+				pub.CanonicalAlias = contentVal
+			case visibilityTuple:
+				pub.WorldReadable = contentVal == "world_readable"
+			// need both of these to determine whether guests can join
+			case joinRuleTuple:
+				joinRule = contentVal
+			case guestTuple:
+				guestAccess = contentVal
+			}
+		}
+		if joinRule == gomatrixserverlib.Public && guestAccess == "can_join" {
+			pub.GuestCanJoin = true
+		}
+		pub.JoinedMembersCount = joinCount
+		chunk[i] = pub
+		i++
+	}
+	return chunk, nil
+}

roomserver/internal/alias.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"time"
 
 	"github.com/matrix-org/dendrite/roomserver/api"
@@ -239,16 +240,19 @@ func (r *RoomserverInternalAPI) sendUpdatedAliasesEvent(
 	}
 	builder.AuthEvents = refs
 
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, roomID)
+	roomInfo, err := r.DB.RoomInfo(ctx, roomID)
 	if err != nil {
 		return err
 	}
+	if roomInfo == nil {
+		return fmt.Errorf("room %s does not exist", roomID)
+	}
 
 	// Build the event
 	now := time.Now()
 	event, err := builder.Build(
 		now, r.Cfg.Matrix.ServerName, r.Cfg.Matrix.KeyID,
-		r.Cfg.Matrix.PrivateKey, roomVersion,
+		r.Cfg.Matrix.PrivateKey, roomInfo.RoomVersion,
 	)
 	if err != nil {
 		return err
@@ -257,7 +261,7 @@ func (r *RoomserverInternalAPI) sendUpdatedAliasesEvent(
 	// Create the request
 	ire := api.InputRoomEvent{
 		Kind:         api.KindNew,
-		Event:        event.Headered(roomVersion),
+		Event:        event.Headered(roomInfo.RoomVersion),
 		AuthEventIDs: event.AuthEventIDs(),
 		SendAsServer: serverName,
 	}

roomserver/internal/api.go

@@ -1,26 +1,129 @@
 package internal
 
 import (
-	"sync"
+	"context"
 
 	"github.com/Shopify/sarama"
 	fsAPI "github.com/matrix-org/dendrite/federationsender/api"
 	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/internal/config"
+	"github.com/matrix-org/dendrite/roomserver/acls"
+	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/roomserver/internal/input"
+	"github.com/matrix-org/dendrite/roomserver/internal/perform"
+	"github.com/matrix-org/dendrite/roomserver/internal/query"
 	"github.com/matrix-org/dendrite/roomserver/storage"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
 // RoomserverInternalAPI is an implementation of api.RoomserverInternalAPI
 type RoomserverInternalAPI struct {
+	*input.Inputer
+	*query.Queryer
+	*perform.Inviter
+	*perform.Joiner
+	*perform.Leaver
+	*perform.Publisher
+	*perform.Backfiller
 	DB                   storage.Database
 	Cfg                  *config.RoomServer
 	Producer             sarama.SyncProducer
 	Cache                caching.RoomServerCaches
 	ServerName           gomatrixserverlib.ServerName
 	KeyRing              gomatrixserverlib.JSONVerifier
-	FedClient            *gomatrixserverlib.FederationClient
-	OutputRoomEventTopic string   // Kafka topic for new output room events
-	mutexes              sync.Map // room ID -> *sync.Mutex, protects calls to processRoomEvent
 	fsAPI                fsAPI.FederationSenderInternalAPI
+	OutputRoomEventTopic string // Kafka topic for new output room events
+}
+
+func NewRoomserverAPI(
+	cfg *config.RoomServer, roomserverDB storage.Database, producer sarama.SyncProducer,
+	outputRoomEventTopic string, caches caching.RoomServerCaches,
+	keyRing gomatrixserverlib.JSONVerifier,
+) *RoomserverInternalAPI {
+	a := &RoomserverInternalAPI{
+		DB:         roomserverDB,
+		Cfg:        cfg,
+		Cache:      caches,
+		ServerName: cfg.Matrix.ServerName,
+		KeyRing:    keyRing,
+		Queryer: &query.Queryer{
+			DB:         roomserverDB,
+			Cache:      caches,
+			ServerACLs: acls.NewServerACLs(roomserverDB),
+		},
+		Inputer: &input.Inputer{
+			DB:                   roomserverDB,
+			OutputRoomEventTopic: outputRoomEventTopic,
+			Producer:             producer,
+			ServerName:           cfg.Matrix.ServerName,
+		},
+		// perform-er structs get initialised when we have a federation sender to use
+	}
+	return a
+}
+
+// SetFederationSenderInputAPI passes in a federation sender input API reference
+// so that we can avoid the chicken-and-egg problem of both the roomserver input API
+// and the federation sender input API being interdependent.
+func (r *RoomserverInternalAPI) SetFederationSenderAPI(fsAPI fsAPI.FederationSenderInternalAPI) {
+	r.fsAPI = fsAPI
+
+	r.Inviter = &perform.Inviter{
+		DB:      r.DB,
+		Cfg:     r.Cfg,
+		FSAPI:   r.fsAPI,
+		Inputer: r.Inputer,
+	}
+	r.Joiner = &perform.Joiner{
+		ServerName: r.Cfg.Matrix.ServerName,
+		Cfg:        r.Cfg,
+		DB:         r.DB,
+		FSAPI:      r.fsAPI,
+		Inputer:    r.Inputer,
+	}
+	r.Leaver = &perform.Leaver{
+		Cfg:     r.Cfg,
+		DB:      r.DB,
+		FSAPI:   r.fsAPI,
+		Inputer: r.Inputer,
+	}
+	r.Publisher = &perform.Publisher{
+		DB: r.DB,
+	}
+	r.Backfiller = &perform.Backfiller{
+		ServerName: r.ServerName,
+		DB:         r.DB,
+		FSAPI:      r.fsAPI,
+		KeyRing:    r.KeyRing,
+	}
+}
+
+func (r *RoomserverInternalAPI) PerformInvite(
+	ctx context.Context,
+	req *api.PerformInviteRequest,
+	res *api.PerformInviteResponse,
+) error {
+	outputEvents, err := r.Inviter.PerformInvite(ctx, req, res)
+	if err != nil {
+		return err
+	}
+	if len(outputEvents) == 0 {
+		return nil
+	}
+	return r.WriteOutputEvents(req.Event.RoomID(), outputEvents)
+}
+
+func (r *RoomserverInternalAPI) PerformLeave(
+	ctx context.Context,
+	req *api.PerformLeaveRequest,
+	res *api.PerformLeaveResponse,
+) error {
+	outputEvents, err := r.Leaver.PerformLeave(ctx, req, res)
+	if err != nil {
+		return err
+	}
+	if len(outputEvents) == 0 {
+		return nil
+	}
+	return r.WriteOutputEvents(req.RoomID, outputEvents)
 }

roomserver/internal/helpers/auth.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package internal
+package helpers
 
 import (
 	"context"
@@ -23,9 +23,9 @@ import (
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
-// checkAuthEvents checks that the event passes authentication checks
+// CheckAuthEvents checks that the event passes authentication checks
 // Returns the numeric IDs for the auth events.
-func checkAuthEvents(
+func CheckAuthEvents(
 	ctx context.Context,
 	db storage.Database,
 	event gomatrixserverlib.HeaderedEvent,
@@ -63,7 +63,7 @@ func checkAuthEvents(
 type authEvents struct {
 	stateKeyNIDMap map[string]types.EventStateKeyNID
 	state          stateEntryMap
-	events         eventMap
+	events         EventMap
 }
 
 // Create implements gomatrixserverlib.AuthEventProvider
@@ -99,7 +99,7 @@ func (ae *authEvents) lookupEventWithEmptyStateKey(typeNID types.EventTypeNID) *
 	if !ok {
 		return nil
 	}
-	event, ok := ae.events.lookup(eventNID)
+	event, ok := ae.events.Lookup(eventNID)
 	if !ok {
 		return nil
 	}
@@ -118,7 +118,7 @@ func (ae *authEvents) lookupEvent(typeNID types.EventTypeNID, stateKey string) *
 	if !ok {
 		return nil
 	}
-	event, ok := ae.events.lookup(eventNID)
+	event, ok := ae.events.Lookup(eventNID)
 	if !ok {
 		return nil
 	}
@@ -224,10 +224,10 @@ func (m stateEntryMap) lookup(stateKey types.StateKeyTuple) (eventNID types.Even
 
 // Map from numeric event ID to event.
 // Implemented using binary search on a sorted array.
-type eventMap []types.Event
+type EventMap []types.Event
 
 // lookup an entry in the event map.
-func (m eventMap) lookup(eventNID types.EventNID) (event *types.Event, ok bool) {
+func (m EventMap) Lookup(eventNID types.EventNID) (event *types.Event, ok bool) {
 	// Since the list is sorted we can implement this using binary search.
 	// This is faster than using a hash map.
 	// We don't have to worry about pathological cases because the keys are fixed

roomserver/internal/helpers/auth_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package internal
+package helpers
 
 import (
 	"testing"
@@ -95,7 +95,7 @@ func TestStateEntryMap(t *testing.T) {
 }
 
 func TestEventMap(t *testing.T) {
-	events := eventMap([]types.Event{
+	events := EventMap([]types.Event{
 		{EventNID: 1},
 		{EventNID: 2},
 		{EventNID: 3},
@@ -123,7 +123,7 @@ func TestEventMap(t *testing.T) {
 	}
 
 	for _, testCase := range testCases {
-		gotEvent, gotOK := events.lookup(testCase.inputEventNID)
+		gotEvent, gotOK := events.Lookup(testCase.inputEventNID)
 		if testCase.wantOK != gotOK {
 			t.Fatalf("eventMap lookup(%v): want ok to be %v, got %v", testCase.inputEventNID, testCase.wantOK, gotOK)
 		}

roomserver/internal/helpers/helpers.go

@@ -0,0 +1,379 @@
+package helpers
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/roomserver/auth"
+	"github.com/matrix-org/dendrite/roomserver/state"
+	"github.com/matrix-org/dendrite/roomserver/storage"
+	"github.com/matrix-org/dendrite/roomserver/storage/shared"
+	"github.com/matrix-org/dendrite/roomserver/types"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+)
+
+// TODO: temporary package which has helper functions used by both internal/perform packages.
+// Move these to a more sensible place.
+
+func UpdateToInviteMembership(
+	mu *shared.MembershipUpdater, add *gomatrixserverlib.Event, updates []api.OutputEvent,
+	roomVersion gomatrixserverlib.RoomVersion,
+) ([]api.OutputEvent, error) {
+	// We may have already sent the invite to the user, either because we are
+	// reprocessing this event, or because the we received this invite from a
+	// remote server via the federation invite API. In those cases we don't need
+	// to send the event.
+	needsSending, err := mu.SetToInvite(*add)
+	if err != nil {
+		return nil, err
+	}
+	if needsSending {
+		// We notify the consumers using a special event even though we will
+		// notify them about the change in current state as part of the normal
+		// room event stream. This ensures that the consumers only have to
+		// consider a single stream of events when determining whether a user
+		// is invited, rather than having to combine multiple streams themselves.
+		onie := api.OutputNewInviteEvent{
+			Event:       add.Headered(roomVersion),
+			RoomVersion: roomVersion,
+		}
+		updates = append(updates, api.OutputEvent{
+			Type:           api.OutputTypeNewInviteEvent,
+			NewInviteEvent: &onie,
+		})
+	}
+	return updates, nil
+}
+
+func IsServerCurrentlyInRoom(ctx context.Context, db storage.Database, serverName gomatrixserverlib.ServerName, roomID string) (bool, error) {
+	info, err := db.RoomInfo(ctx, roomID)
+	if err != nil {
+		return false, err
+	}
+	if info == nil {
+		return false, fmt.Errorf("unknown room %s", roomID)
+	}
+
+	eventNIDs, err := db.GetMembershipEventNIDsForRoom(ctx, info.RoomNID, true, false)
+	if err != nil {
+		return false, err
+	}
+
+	events, err := db.Events(ctx, eventNIDs)
+	if err != nil {
+		return false, err
+	}
+	gmslEvents := make([]gomatrixserverlib.Event, len(events))
+	for i := range events {
+		gmslEvents[i] = events[i].Event
+	}
+	return auth.IsAnyUserOnServerWithMembership(serverName, gmslEvents, gomatrixserverlib.Join), nil
+}
+
+func IsInvitePending(
+	ctx context.Context, db storage.Database,
+	roomID, userID string,
+) (bool, string, string, error) {
+	// Look up the room NID for the supplied room ID.
+	info, err := db.RoomInfo(ctx, roomID)
+	if err != nil {
+		return false, "", "", fmt.Errorf("r.DB.RoomInfo: %w", err)
+	}
+	if info == nil {
+		return false, "", "", fmt.Errorf("cannot get RoomInfo: unknown room ID %s", roomID)
+	}
+
+	// Look up the state key NID for the supplied user ID.
+	targetUserNIDs, err := db.EventStateKeyNIDs(ctx, []string{userID})
+	if err != nil {
+		return false, "", "", fmt.Errorf("r.DB.EventStateKeyNIDs: %w", err)
+	}
+	targetUserNID, targetUserFound := targetUserNIDs[userID]
+	if !targetUserFound {
+		return false, "", "", fmt.Errorf("missing NID for user %q (%+v)", userID, targetUserNIDs)
+	}
+
+	// Let's see if we have an event active for the user in the room. If
+	// we do then it will contain a server name that we can direct the
+	// send_leave to.
+	senderUserNIDs, eventIDs, err := db.GetInvitesForUser(ctx, info.RoomNID, targetUserNID)
+	if err != nil {
+		return false, "", "", fmt.Errorf("r.DB.GetInvitesForUser: %w", err)
+	}
+	if len(senderUserNIDs) == 0 {
+		return false, "", "", nil
+	}
+	userNIDToEventID := make(map[types.EventStateKeyNID]string)
+	for i, nid := range senderUserNIDs {
+		userNIDToEventID[nid] = eventIDs[i]
+	}
+
+	// Look up the user ID from the NID.
+	senderUsers, err := db.EventStateKeys(ctx, senderUserNIDs)
+	if err != nil {
+		return false, "", "", fmt.Errorf("r.DB.EventStateKeys: %w", err)
+	}
+	if len(senderUsers) == 0 {
+		return false, "", "", fmt.Errorf("no senderUsers")
+	}
+
+	senderUser, senderUserFound := senderUsers[senderUserNIDs[0]]
+	if !senderUserFound {
+		return false, "", "", fmt.Errorf("missing user for NID %d (%+v)", senderUserNIDs[0], senderUsers)
+	}
+
+	return true, senderUser, userNIDToEventID[senderUserNIDs[0]], nil
+}
+
+// GetMembershipsAtState filters the state events to
+// only keep the "m.room.member" events with a "join" membership. These events are returned.
+// Returns an error if there was an issue fetching the events.
+func GetMembershipsAtState(
+	ctx context.Context, db storage.Database, stateEntries []types.StateEntry, joinedOnly bool,
+) ([]types.Event, error) {
+
+	var eventNIDs []types.EventNID
+	for _, entry := range stateEntries {
+		// Filter the events to retrieve to only keep the membership events
+		if entry.EventTypeNID == types.MRoomMemberNID {
+			eventNIDs = append(eventNIDs, entry.EventNID)
+		}
+	}
+
+	// Get all of the events in this state
+	stateEvents, err := db.Events(ctx, eventNIDs)
+	if err != nil {
+		return nil, err
+	}
+
+	if !joinedOnly {
+		return stateEvents, nil
+	}
+
+	// Filter the events to only keep the "join" membership events
+	var events []types.Event
+	for _, event := range stateEvents {
+		membership, err := event.Membership()
+		if err != nil {
+			return nil, err
+		}
+
+		if membership == gomatrixserverlib.Join {
+			events = append(events, event)
+		}
+	}
+
+	return events, nil
+}
+
+func StateBeforeEvent(ctx context.Context, db storage.Database, info types.RoomInfo, eventNID types.EventNID) ([]types.StateEntry, error) {
+	roomState := state.NewStateResolution(db, info)
+	// Lookup the event NID
+	eIDs, err := db.EventIDs(ctx, []types.EventNID{eventNID})
+	if err != nil {
+		return nil, err
+	}
+	eventIDs := []string{eIDs[eventNID]}
+
+	prevState, err := db.StateAtEventIDs(ctx, eventIDs)
+	if err != nil {
+		return nil, err
+	}
+
+	// Fetch the state as it was when this event was fired
+	return roomState.LoadCombinedStateAfterEvents(ctx, prevState)
+}
+
+func LoadEvents(
+	ctx context.Context, db storage.Database, eventNIDs []types.EventNID,
+) ([]gomatrixserverlib.Event, error) {
+	stateEvents, err := db.Events(ctx, eventNIDs)
+	if err != nil {
+		return nil, err
+	}
+
+	result := make([]gomatrixserverlib.Event, len(stateEvents))
+	for i := range stateEvents {
+		result[i] = stateEvents[i].Event
+	}
+	return result, nil
+}
+
+func LoadStateEvents(
+	ctx context.Context, db storage.Database, stateEntries []types.StateEntry,
+) ([]gomatrixserverlib.Event, error) {
+	eventNIDs := make([]types.EventNID, len(stateEntries))
+	for i := range stateEntries {
+		eventNIDs[i] = stateEntries[i].EventNID
+	}
+	return LoadEvents(ctx, db, eventNIDs)
+}
+
+func CheckServerAllowedToSeeEvent(
+	ctx context.Context, db storage.Database, info types.RoomInfo, eventID string, serverName gomatrixserverlib.ServerName, isServerInRoom bool,
+) (bool, error) {
+	roomState := state.NewStateResolution(db, info)
+	stateEntries, err := roomState.LoadStateAtEvent(ctx, eventID)
+	if err != nil {
+		return false, err
+	}
+
+	// TODO: We probably want to make it so that we don't have to pull
+	// out all the state if possible.
+	stateAtEvent, err := LoadStateEvents(ctx, db, stateEntries)
+	if err != nil {
+		return false, err
+	}
+
+	return auth.IsServerAllowed(serverName, isServerInRoom, stateAtEvent), nil
+}
+
+// TODO: Remove this when we have tests to assert correctness of this function
+// nolint:gocyclo
+func ScanEventTree(
+	ctx context.Context, db storage.Database, info types.RoomInfo, front []string, visited map[string]bool, limit int,
+	serverName gomatrixserverlib.ServerName,
+) ([]types.EventNID, error) {
+	var resultNIDs []types.EventNID
+	var err error
+	var allowed bool
+	var events []types.Event
+	var next []string
+	var pre string
+
+	// TODO: add tests for this function to ensure it meets the contract that callers expect (and doc what that is supposed to be)
+	// Currently, callers like PerformBackfill will call scanEventTree with a pre-populated `visited` map, assuming that by doing
+	// so means that the events in that map will NOT be returned from this function. That is not currently true, resulting in
+	// duplicate events being sent in response to /backfill requests.
+	initialIgnoreList := make(map[string]bool, len(visited))
+	for k, v := range visited {
+		initialIgnoreList[k] = v
+	}
+
+	resultNIDs = make([]types.EventNID, 0, limit)
+
+	var checkedServerInRoom bool
+	var isServerInRoom bool
+
+	// Loop through the event IDs to retrieve the requested events and go
+	// through the whole tree (up to the provided limit) using the events'
+	// "prev_event" key.
+BFSLoop:
+	for len(front) > 0 {
+		// Prevent unnecessary allocations: reset the slice only when not empty.
+		if len(next) > 0 {
+			next = make([]string, 0)
+		}
+		// Retrieve the events to process from the database.
+		events, err = db.EventsFromIDs(ctx, front)
+		if err != nil {
+			return resultNIDs, err
+		}
+
+		if !checkedServerInRoom && len(events) > 0 {
+			// It's nasty that we have to extract the room ID from an event, but many federation requests
+			// only talk in event IDs, no room IDs at all (!!!)
+			ev := events[0]
+			isServerInRoom, err = IsServerCurrentlyInRoom(ctx, db, serverName, ev.RoomID())
+			if err != nil {
+				util.GetLogger(ctx).WithError(err).Error("Failed to check if server is currently in room, assuming not.")
+			}
+			checkedServerInRoom = true
+		}
+
+		for _, ev := range events {
+			// Break out of the loop if the provided limit is reached.
+			if len(resultNIDs) == limit {
+				break BFSLoop
+			}
+
+			if !initialIgnoreList[ev.EventID()] {
+				// Update the list of events to retrieve.
+				resultNIDs = append(resultNIDs, ev.EventNID)
+			}
+			// Loop through the event's parents.
+			for _, pre = range ev.PrevEventIDs() {
+				// Only add an event to the list of next events to process if it
+				// hasn't been seen before.
+				if !visited[pre] {
+					visited[pre] = true
+					allowed, err = CheckServerAllowedToSeeEvent(ctx, db, info, pre, serverName, isServerInRoom)
+					if err != nil {
+						util.GetLogger(ctx).WithField("server", serverName).WithField("event_id", pre).WithError(err).Error(
+							"Error checking if allowed to see event",
+						)
+						return resultNIDs, err
+					}
+
+					// If the event hasn't been seen before and the HS
+					// requesting to retrieve it is allowed to do so, add it to
+					// the list of events to retrieve.
+					if allowed {
+						next = append(next, pre)
+					} else {
+						util.GetLogger(ctx).WithField("server", serverName).WithField("event_id", pre).Info("Not allowed to see event")
+					}
+				}
+			}
+		}
+		// Repeat the same process with the parent events we just processed.
+		front = next
+	}
+
+	return resultNIDs, err
+}
+
+func QueryLatestEventsAndState(
+	ctx context.Context, db storage.Database,
+	request *api.QueryLatestEventsAndStateRequest,
+	response *api.QueryLatestEventsAndStateResponse,
+) error {
+	roomInfo, err := db.RoomInfo(ctx, request.RoomID)
+	if err != nil {
+		return err
+	}
+	if roomInfo == nil || roomInfo.IsStub {
+		response.RoomExists = false
+		return nil
+	}
+
+	roomState := state.NewStateResolution(db, *roomInfo)
+	response.RoomExists = true
+	response.RoomVersion = roomInfo.RoomVersion
+
+	var currentStateSnapshotNID types.StateSnapshotNID
+	response.LatestEvents, currentStateSnapshotNID, response.Depth, err =
+		db.LatestEventIDs(ctx, roomInfo.RoomNID)
+	if err != nil {
+		return err
+	}
+
+	var stateEntries []types.StateEntry
+	if len(request.StateToFetch) == 0 {
+		// Look up all room state.
+		stateEntries, err = roomState.LoadStateAtSnapshot(
+			ctx, currentStateSnapshotNID,
+		)
+	} else {
+		// Look up the current state for the requested tuples.
+		stateEntries, err = roomState.LoadStateAtSnapshotForStringTuples(
+			ctx, currentStateSnapshotNID, request.StateToFetch,
+		)
+	}
+	if err != nil {
+		return err
+	}
+
+	stateEvents, err := LoadStateEvents(ctx, db, stateEntries)
+	if err != nil {
+		return err
+	}
+
+	for _, event := range stateEvents {
+		response.StateEvents = append(response.StateEvents, event.Headered(roomInfo.RoomVersion))
+	}
+
+	return nil
+}

roomserver/internal/input.go

@@ -1,89 +0,0 @@
-// Copyright 2017 Vector Creations Ltd
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package input contains the code processes new room events
-package internal
-
-import (
-	"context"
-	"encoding/json"
-	"sync"
-
-	"github.com/Shopify/sarama"
-	"github.com/matrix-org/dendrite/roomserver/api"
-	log "github.com/sirupsen/logrus"
-
-	fsAPI "github.com/matrix-org/dendrite/federationsender/api"
-)
-
-// SetFederationSenderInputAPI passes in a federation sender input API reference
-// so that we can avoid the chicken-and-egg problem of both the roomserver input API
-// and the federation sender input API being interdependent.
-func (r *RoomserverInternalAPI) SetFederationSenderAPI(fsAPI fsAPI.FederationSenderInternalAPI) {
-	r.fsAPI = fsAPI
-}
-
-// WriteOutputEvents implements OutputRoomEventWriter
-func (r *RoomserverInternalAPI) WriteOutputEvents(roomID string, updates []api.OutputEvent) error {
-	messages := make([]*sarama.ProducerMessage, len(updates))
-	for i := range updates {
-		value, err := json.Marshal(updates[i])
-		if err != nil {
-			return err
-		}
-		logger := log.WithFields(log.Fields{
-			"room_id": roomID,
-			"type":    updates[i].Type,
-		})
-		if updates[i].NewRoomEvent != nil {
-			logger = logger.WithFields(log.Fields{
-				"event_type":     updates[i].NewRoomEvent.Event.Type(),
-				"event_id":       updates[i].NewRoomEvent.Event.EventID(),
-				"adds_state":     len(updates[i].NewRoomEvent.AddsStateEventIDs),
-				"removes_state":  len(updates[i].NewRoomEvent.RemovesStateEventIDs),
-				"send_as_server": updates[i].NewRoomEvent.SendAsServer,
-				"sender":         updates[i].NewRoomEvent.Event.Sender(),
-			})
-		}
-		logger.Infof("Producing to topic '%s'", r.OutputRoomEventTopic)
-		messages[i] = &sarama.ProducerMessage{
-			Topic: r.OutputRoomEventTopic,
-			Key:   sarama.StringEncoder(roomID),
-			Value: sarama.ByteEncoder(value),
-		}
-	}
-	return r.Producer.SendMessages(messages)
-}
-
-// InputRoomEvents implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) InputRoomEvents(
-	ctx context.Context,
-	request *api.InputRoomEventsRequest,
-	response *api.InputRoomEventsResponse,
-) (err error) {
-	for i, e := range request.InputRoomEvents {
-		roomID := "global"
-		if r.DB.SupportsConcurrentRoomInputs() {
-			roomID = e.Event.RoomID()
-		}
-		mutex, _ := r.mutexes.LoadOrStore(roomID, &sync.Mutex{})
-		mutex.(*sync.Mutex).Lock()
-		if response.EventID, err = r.processRoomEvent(ctx, request.InputRoomEvents[i]); err != nil {
-			mutex.(*sync.Mutex).Unlock()
-			return err
-		}
-		mutex.(*sync.Mutex).Unlock()
-	}
-	return nil
-}

roomserver/internal/input/input.go

@@ -0,0 +1,157 @@
+// Copyright 2017 Vector Creations Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package input contains the code processes new room events
+package input
+
+import (
+	"context"
+	"encoding/json"
+	"sync"
+	"time"
+
+	"github.com/Shopify/sarama"
+	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/roomserver/storage"
+	"github.com/matrix-org/gomatrixserverlib"
+	log "github.com/sirupsen/logrus"
+	"go.uber.org/atomic"
+)
+
+type Inputer struct {
+	DB                   storage.Database
+	Producer             sarama.SyncProducer
+	ServerName           gomatrixserverlib.ServerName
+	OutputRoomEventTopic string
+
+	workers sync.Map // room ID -> *inputWorker
+}
+
+type inputTask struct {
+	ctx   context.Context
+	event *api.InputRoomEvent
+	wg    *sync.WaitGroup
+	err   error // written back by worker, only safe to read when all tasks are done
+}
+
+type inputWorker struct {
+	r       *Inputer
+	running atomic.Bool
+	input   chan *inputTask
+}
+
+func (w *inputWorker) start() {
+	if !w.running.CAS(false, true) {
+		return
+	}
+	defer w.running.Store(false)
+	for {
+		select {
+		case task := <-w.input:
+			_, task.err = w.r.processRoomEvent(task.ctx, task.event)
+			task.wg.Done()
+		case <-time.After(time.Second * 5):
+			return
+		}
+	}
+}
+
+// WriteOutputEvents implements OutputRoomEventWriter
+func (r *Inputer) WriteOutputEvents(roomID string, updates []api.OutputEvent) error {
+	messages := make([]*sarama.ProducerMessage, len(updates))
+	for i := range updates {
+		value, err := json.Marshal(updates[i])
+		if err != nil {
+			return err
+		}
+		logger := log.WithFields(log.Fields{
+			"room_id": roomID,
+			"type":    updates[i].Type,
+		})
+		if updates[i].NewRoomEvent != nil {
+			logger = logger.WithFields(log.Fields{
+				"event_type":     updates[i].NewRoomEvent.Event.Type(),
+				"event_id":       updates[i].NewRoomEvent.Event.EventID(),
+				"adds_state":     len(updates[i].NewRoomEvent.AddsStateEventIDs),
+				"removes_state":  len(updates[i].NewRoomEvent.RemovesStateEventIDs),
+				"send_as_server": updates[i].NewRoomEvent.SendAsServer,
+				"sender":         updates[i].NewRoomEvent.Event.Sender(),
+			})
+		}
+		logger.Infof("Producing to topic '%s'", r.OutputRoomEventTopic)
+		messages[i] = &sarama.ProducerMessage{
+			Topic: r.OutputRoomEventTopic,
+			Key:   sarama.StringEncoder(roomID),
+			Value: sarama.ByteEncoder(value),
+		}
+	}
+	return r.Producer.SendMessages(messages)
+}
+
+// InputRoomEvents implements api.RoomserverInternalAPI
+func (r *Inputer) InputRoomEvents(
+	ctx context.Context,
+	request *api.InputRoomEventsRequest,
+	response *api.InputRoomEventsResponse,
+) error {
+	// Create a wait group. Each task that we dispatch will call Done on
+	// this wait group so that we know when all of our events have been
+	// processed.
+	wg := &sync.WaitGroup{}
+	wg.Add(len(request.InputRoomEvents))
+	tasks := make([]*inputTask, len(request.InputRoomEvents))
+
+	for i, e := range request.InputRoomEvents {
+		// Work out if we are running per-room workers or if we're just doing
+		// it on a global basis (e.g. SQLite).
+		roomID := "global"
+		if r.DB.SupportsConcurrentRoomInputs() {
+			roomID = e.Event.RoomID()
+		}
+
+		// Look up the worker, or create it if it doesn't exist. This channel
+		// is buffered to reduce the chance that we'll be blocked by another
+		// room - the channel will be quite small as it's just pointer types.
+		w, _ := r.workers.LoadOrStore(roomID, &inputWorker{
+			r:     r,
+			input: make(chan *inputTask, 10),
+		})
+		worker := w.(*inputWorker)
+
+		// Create a task. This contains the input event and a reference to
+		// the wait group, so that the worker can notify us when this specific
+		// task has been finished.
+		tasks[i] = &inputTask{
+			ctx:   ctx,
+			event: &request.InputRoomEvents[i],
+			wg:    wg,
+		}
+
+		// Send the task to the worker.
+		go worker.start()
+		worker.input <- tasks[i]
+	}
+
+	// Wait for all of the workers to return results about our tasks.
+	wg.Wait()
+
+	// If any of the tasks returned an error, we should probably report
+	// that back to the caller.
+	for _, task := range tasks {
+		if task.err != nil {
+			return task.err
+		}
+	}
+	return nil
+}

roomserver/internal/input/input_events.go

@@ -14,7 +14,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package internal
+package input
 
 import (
 	"context"
@@ -22,6 +22,7 @@ import (
 
 	"github.com/matrix-org/dendrite/internal/eventutil"
 	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/roomserver/internal/helpers"
 	"github.com/matrix-org/dendrite/roomserver/state"
 	"github.com/matrix-org/dendrite/roomserver/types"
 	"github.com/matrix-org/gomatrixserverlib"
@@ -35,9 +36,9 @@ import (
 // state deltas when sending to kafka streams
 // TODO: Break up function - we should probably do transaction ID checks before calling this.
 // nolint:gocyclo
-func (r *RoomserverInternalAPI) processRoomEvent(
+func (r *Inputer) processRoomEvent(
 	ctx context.Context,
-	input api.InputRoomEvent,
+	input *api.InputRoomEvent,
 ) (eventID string, err error) {
 	// Parse and validate the event JSON
 	headered := input.Event
@@ -45,7 +46,7 @@ func (r *RoomserverInternalAPI) processRoomEvent(
 
 	// Check that the event passes authentication checks and work out
 	// the numeric IDs for the auth events.
-	authEventNIDs, err := checkAuthEvents(ctx, r.DB, headered, input.AuthEventIDs)
+	authEventNIDs, err := helpers.CheckAuthEvents(ctx, r.DB, headered, input.AuthEventIDs)
 	if err != nil {
 		logrus.WithError(err).WithField("event_id", event.EventID()).WithField("auth_event_ids", input.AuthEventIDs).Error("processRoomEvent.checkAuthEvents failed for event")
 		return
@@ -64,7 +65,7 @@ func (r *RoomserverInternalAPI) processRoomEvent(
 	}
 
 	// Store the event.
-	roomNID, stateAtEvent, redactionEvent, redactedEventID, err := r.DB.StoreEvent(ctx, event, input.TransactionID, authEventNIDs)
+	_, stateAtEvent, redactionEvent, redactedEventID, err := r.DB.StoreEvent(ctx, event, input.TransactionID, authEventNIDs)
 	if err != nil {
 		return "", fmt.Errorf("r.DB.StoreEvent: %w", err)
 	}
@@ -89,10 +90,18 @@ func (r *RoomserverInternalAPI) processRoomEvent(
 		return event.EventID(), nil
 	}
 
+	roomInfo, err := r.DB.RoomInfo(ctx, event.RoomID())
+	if err != nil {
+		return "", fmt.Errorf("r.DB.RoomInfo: %w", err)
+	}
+	if roomInfo == nil {
+		return "", fmt.Errorf("r.DB.RoomInfo missing for room %s", event.RoomID())
+	}
+
 	if stateAtEvent.BeforeStateSnapshotNID == 0 {
 		// We haven't calculated a state for this event yet.
 		// Lets calculate one.
-		err = r.calculateAndSetState(ctx, input, roomNID, &stateAtEvent, event)
+		err = r.calculateAndSetState(ctx, input, *roomInfo, &stateAtEvent, event)
 		if err != nil {
 			return "", fmt.Errorf("r.calculateAndSetState: %w", err)
 		}
@@ -100,7 +109,7 @@ func (r *RoomserverInternalAPI) processRoomEvent(
 
 	if err = r.updateLatestEvents(
 		ctx,                 // context
-		roomNID,             // room NID to update
+		roomInfo,            // room info for the room being updated
 		stateAtEvent,        // state at event (below)
 		event,               // event
 		input.SendAsServer,  // send as server
@@ -132,22 +141,22 @@ func (r *RoomserverInternalAPI) processRoomEvent(
 	return event.EventID(), nil
 }
 
-func (r *RoomserverInternalAPI) calculateAndSetState(
+func (r *Inputer) calculateAndSetState(
 	ctx context.Context,
-	input api.InputRoomEvent,
-	roomNID types.RoomNID,
+	input *api.InputRoomEvent,
+	roomInfo types.RoomInfo,
 	stateAtEvent *types.StateAtEvent,
 	event gomatrixserverlib.Event,
 ) error {
 	var err error
-	roomState := state.NewStateResolution(r.DB)
+	roomState := state.NewStateResolution(r.DB, roomInfo)
 
 	if input.HasState {
 		// Check here if we think we're in the room already.
 		stateAtEvent.Overwrite = true
 		var joinEventNIDs []types.EventNID
 		// Request join memberships only for local users only.
-		if joinEventNIDs, err = r.DB.GetMembershipEventNIDsForRoom(ctx, roomNID, true, true); err == nil {
+		if joinEventNIDs, err = r.DB.GetMembershipEventNIDsForRoom(ctx, roomInfo.RoomNID, true, true); err == nil {
 			// If we have no local users that are joined to the room then any state about
 			// the room that we have is quite possibly out of date. Therefore in that case
 			// we should overwrite it rather than merge it.
@@ -161,14 +170,14 @@ func (r *RoomserverInternalAPI) calculateAndSetState(
 			return err
 		}
 
-		if stateAtEvent.BeforeStateSnapshotNID, err = r.DB.AddState(ctx, roomNID, nil, entries); err != nil {
+		if stateAtEvent.BeforeStateSnapshotNID, err = r.DB.AddState(ctx, roomInfo.RoomNID, nil, entries); err != nil {
 			return err
 		}
 	} else {
 		stateAtEvent.Overwrite = false
 
 		// We haven't been told what the state at the event is so we need to calculate it from the prev_events
-		if stateAtEvent.BeforeStateSnapshotNID, err = roomState.CalculateAndStoreStateBeforeEvent(ctx, event, roomNID); err != nil {
+		if stateAtEvent.BeforeStateSnapshotNID, err = roomState.CalculateAndStoreStateBeforeEvent(ctx, event); err != nil {
 			return err
 		}
 	}

roomserver/internal/input/input_latest_events.go

@@ -14,7 +14,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package internal
+package input
 
 import (
 	"bytes"
@@ -47,15 +47,15 @@ import (
 //      7 <----- latest
 //
 // Can only be called once at a time
-func (r *RoomserverInternalAPI) updateLatestEvents(
+func (r *Inputer) updateLatestEvents(
 	ctx context.Context,
-	roomNID types.RoomNID,
+	roomInfo *types.RoomInfo,
 	stateAtEvent types.StateAtEvent,
 	event gomatrixserverlib.Event,
 	sendAsServer string,
 	transactionID *api.TransactionID,
 ) (err error) {
-	updater, err := r.DB.GetLatestEventsForUpdate(ctx, roomNID)
+	updater, err := r.DB.GetLatestEventsForUpdate(ctx, *roomInfo)
 	if err != nil {
 		return fmt.Errorf("r.DB.GetLatestEventsForUpdate: %w", err)
 	}
@@ -66,7 +66,7 @@ func (r *RoomserverInternalAPI) updateLatestEvents(
 		ctx:           ctx,
 		api:           r,
 		updater:       updater,
-		roomNID:       roomNID,
+		roomInfo:      roomInfo,
 		stateAtEvent:  stateAtEvent,
 		event:         event,
 		sendAsServer:  sendAsServer,
@@ -87,9 +87,9 @@ func (r *RoomserverInternalAPI) updateLatestEvents(
 // when there are so many variables to pass around.
 type latestEventsUpdater struct {
 	ctx           context.Context
-	api           *RoomserverInternalAPI
+	api           *Inputer
 	updater       *shared.LatestEventsUpdater
-	roomNID       types.RoomNID
+	roomInfo      *types.RoomInfo
 	stateAtEvent  types.StateAtEvent
 	event         gomatrixserverlib.Event
 	transactionID *api.TransactionID
@@ -196,7 +196,7 @@ func (u *latestEventsUpdater) doUpdateLatestEvents() error {
 		return fmt.Errorf("u.api.WriteOutputEvents: %w", err)
 	}
 
-	if err = u.updater.SetLatestEvents(u.roomNID, u.latest, u.stateAtEvent.EventNID, u.newStateNID); err != nil {
+	if err = u.updater.SetLatestEvents(u.roomInfo.RoomNID, u.latest, u.stateAtEvent.EventNID, u.newStateNID); err != nil {
 		return fmt.Errorf("u.updater.SetLatestEvents: %w", err)
 	}
 
@@ -209,7 +209,7 @@ func (u *latestEventsUpdater) doUpdateLatestEvents() error {
 
 func (u *latestEventsUpdater) latestState() error {
 	var err error
-	roomState := state.NewStateResolution(u.api.DB)
+	roomState := state.NewStateResolution(u.api.DB, *u.roomInfo)
 
 	// Get a list of the current latest events.
 	latestStateAtEvents := make([]types.StateAtEvent, len(u.latest))
@@ -221,7 +221,7 @@ func (u *latestEventsUpdater) latestState() error {
 	// of the state after the events. The snapshot state will be resolved
 	// using the correct state resolution algorithm for the room.
 	u.newStateNID, err = roomState.CalculateAndStoreStateAfterEvents(
-		u.ctx, u.roomNID, latestStateAtEvents,
+		u.ctx, latestStateAtEvents,
 	)
 	if err != nil {
 		return fmt.Errorf("roomState.CalculateAndStoreStateAfterEvents: %w", err)
@@ -303,13 +303,8 @@ func (u *latestEventsUpdater) makeOutputNewRoomEvent() (*api.OutputEvent, error)
 		latestEventIDs[i] = u.latest[i].EventID
 	}
 
-	roomVersion, err := u.api.DB.GetRoomVersionForRoom(u.ctx, u.event.RoomID())
-	if err != nil {
-		return nil, err
-	}
-
 	ore := api.OutputNewRoomEvent{
-		Event:           u.event.Headered(roomVersion),
+		Event:           u.event.Headered(u.roomInfo.RoomVersion),
 		LastSentEventID: u.lastEventIDSent,
 		LatestEventIDs:  latestEventIDs,
 		TransactionID:   u.transactionID,
@@ -337,7 +332,7 @@ func (u *latestEventsUpdater) makeOutputNewRoomEvent() (*api.OutputEvent, error)
 	// include extra state events if they were added as nearly every downstream component will care about it
 	// and we'd rather not have them all hit QueryEventsByID at the same time!
 	if len(ore.AddsStateEventIDs) > 0 {
-		ore.AddStateEvents, err = u.extraEventsForIDs(roomVersion, ore.AddsStateEventIDs)
+		ore.AddStateEvents, err = u.extraEventsForIDs(u.roomInfo.RoomVersion, ore.AddsStateEventIDs)
 		if err != nil {
 			return nil, fmt.Errorf("failed to load add_state_events from db: %w", err)
 		}

roomserver/internal/input/input_membership.go

@@ -12,13 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package internal
+package input
 
 import (
 	"context"
 	"fmt"
 
 	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/roomserver/internal/helpers"
 	"github.com/matrix-org/dendrite/roomserver/storage/shared"
 	"github.com/matrix-org/dendrite/roomserver/types"
 	"github.com/matrix-org/gomatrixserverlib"
@@ -28,7 +29,7 @@ import (
 // user affected by a change in the current state of the room.
 // Returns a list of output events to write to the kafka log to inform the
 // consumers about the invites added or retired by the change in current state.
-func (r *RoomserverInternalAPI) updateMemberships(
+func (r *Inputer) updateMemberships(
 	ctx context.Context,
 	updater *shared.LatestEventsUpdater,
 	removed, added []types.StateEntry,
@@ -59,13 +60,13 @@ func (r *RoomserverInternalAPI) updateMemberships(
 		var re *gomatrixserverlib.Event
 		targetUserNID := change.EventStateKeyNID
 		if change.removedEventNID != 0 {
-			ev, _ := eventMap(events).lookup(change.removedEventNID)
+			ev, _ := helpers.EventMap(events).Lookup(change.removedEventNID)
 			if ev != nil {
 				re = &ev.Event
 			}
 		}
 		if change.addedEventNID != 0 {
-			ev, _ := eventMap(events).lookup(change.addedEventNID)
+			ev, _ := helpers.EventMap(events).Lookup(change.addedEventNID)
 			if ev != nil {
 				ae = &ev.Event
 			}
@@ -77,7 +78,7 @@ func (r *RoomserverInternalAPI) updateMemberships(
 	return updates, nil
 }
 
-func (r *RoomserverInternalAPI) updateMembership(
+func (r *Inputer) updateMembership(
 	updater *shared.LatestEventsUpdater,
 	targetUserNID types.EventStateKeyNID,
 	remove, add *gomatrixserverlib.Event,
@@ -120,7 +121,7 @@ func (r *RoomserverInternalAPI) updateMembership(
 
 	switch newMembership {
 	case gomatrixserverlib.Invite:
-		return updateToInviteMembership(mu, add, updates, updater.RoomVersion())
+		return helpers.UpdateToInviteMembership(mu, add, updates, updater.RoomVersion())
 	case gomatrixserverlib.Join:
 		return updateToJoinMembership(mu, add, updates)
 	case gomatrixserverlib.Leave, gomatrixserverlib.Ban:
@@ -132,45 +133,15 @@ func (r *RoomserverInternalAPI) updateMembership(
 	}
 }
 
-func (r *RoomserverInternalAPI) isLocalTarget(event *gomatrixserverlib.Event) bool {
+func (r *Inputer) isLocalTarget(event *gomatrixserverlib.Event) bool {
 	isTargetLocalUser := false
 	if statekey := event.StateKey(); statekey != nil {
 		_, domain, _ := gomatrixserverlib.SplitID('@', *statekey)
-		isTargetLocalUser = domain == r.Cfg.Matrix.ServerName
+		isTargetLocalUser = domain == r.ServerName
 	}
 	return isTargetLocalUser
 }
 
-func updateToInviteMembership(
-	mu *shared.MembershipUpdater, add *gomatrixserverlib.Event, updates []api.OutputEvent,
-	roomVersion gomatrixserverlib.RoomVersion,
-) ([]api.OutputEvent, error) {
-	// We may have already sent the invite to the user, either because we are
-	// reprocessing this event, or because the we received this invite from a
-	// remote server via the federation invite API. In those cases we don't need
-	// to send the event.
-	needsSending, err := mu.SetToInvite(*add)
-	if err != nil {
-		return nil, err
-	}
-	if needsSending {
-		// We notify the consumers using a special event even though we will
-		// notify them about the change in current state as part of the normal
-		// room event stream. This ensures that the consumers only have to
-		// consider a single stream of events when determining whether a user
-		// is invited, rather than having to combine multiple streams themselves.
-		onie := api.OutputNewInviteEvent{
-			Event:       add.Headered(roomVersion),
-			RoomVersion: roomVersion,
-		}
-		updates = append(updates, api.OutputEvent{
-			Type:           api.OutputTypeNewInviteEvent,
-			NewInviteEvent: &onie,
-		})
-	}
-	return updates, nil
-}
-
 func updateToJoinMembership(
 	mu *shared.MembershipUpdater, add *gomatrixserverlib.Event, updates []api.OutputEvent,
 ) ([]api.OutputEvent, error) {

roomserver/internal/perform/perform_backfill.go

@@ -0,0 +1,562 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package perform
+
+import (
+	"context"
+	"fmt"
+
+	federationSenderAPI "github.com/matrix-org/dendrite/federationsender/api"
+	"github.com/matrix-org/dendrite/internal/eventutil"
+	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/roomserver/auth"
+	"github.com/matrix-org/dendrite/roomserver/internal/helpers"
+	"github.com/matrix-org/dendrite/roomserver/storage"
+	"github.com/matrix-org/dendrite/roomserver/types"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+	"github.com/sirupsen/logrus"
+)
+
+type Backfiller struct {
+	ServerName gomatrixserverlib.ServerName
+	DB         storage.Database
+	FSAPI      federationSenderAPI.FederationSenderInternalAPI
+	KeyRing    gomatrixserverlib.JSONVerifier
+}
+
+// PerformBackfill implements api.RoomServerQueryAPI
+func (r *Backfiller) PerformBackfill(
+	ctx context.Context,
+	request *api.PerformBackfillRequest,
+	response *api.PerformBackfillResponse,
+) error {
+	// if we are requesting the backfill then we need to do a federation hit
+	// TODO: we could be more sensible and fetch as many events we already have then request the rest
+	//       which is what the syncapi does already.
+	if request.ServerName == r.ServerName {
+		return r.backfillViaFederation(ctx, request, response)
+	}
+	// someone else is requesting the backfill, try to service their request.
+	var err error
+	var front []string
+
+	// The limit defines the maximum number of events to retrieve, so it also
+	// defines the highest number of elements in the map below.
+	visited := make(map[string]bool, request.Limit)
+
+	// this will include these events which is what we want
+	front = request.PrevEventIDs()
+
+	info, err := r.DB.RoomInfo(ctx, request.RoomID)
+	if err != nil {
+		return err
+	}
+	if info == nil || info.IsStub {
+		return fmt.Errorf("PerformBackfill: missing room info for room %s", request.RoomID)
+	}
+
+	// Scan the event tree for events to send back.
+	resultNIDs, err := helpers.ScanEventTree(ctx, r.DB, *info, front, visited, request.Limit, request.ServerName)
+	if err != nil {
+		return err
+	}
+
+	// Retrieve events from the list that was filled previously.
+	var loadedEvents []gomatrixserverlib.Event
+	loadedEvents, err = helpers.LoadEvents(ctx, r.DB, resultNIDs)
+	if err != nil {
+		return err
+	}
+
+	for _, event := range loadedEvents {
+		response.Events = append(response.Events, event.Headered(info.RoomVersion))
+	}
+
+	return err
+}
+
+func (r *Backfiller) backfillViaFederation(ctx context.Context, req *api.PerformBackfillRequest, res *api.PerformBackfillResponse) error {
+	info, err := r.DB.RoomInfo(ctx, req.RoomID)
+	if err != nil {
+		return err
+	}
+	if info == nil || info.IsStub {
+		return fmt.Errorf("backfillViaFederation: missing room info for room %s", req.RoomID)
+	}
+	requester := newBackfillRequester(r.DB, r.FSAPI, r.ServerName, req.BackwardsExtremities)
+	// Request 100 items regardless of what the query asks for.
+	// We don't want to go much higher than this.
+	// We can't honour exactly the limit as some sytests rely on requesting more for tests to pass
+	// (so we don't need to hit /state_ids which the test has no listener for)
+	// Specifically the test "Outbound federation can backfill events"
+	events, err := gomatrixserverlib.RequestBackfill(
+		ctx, requester,
+		r.KeyRing, req.RoomID, info.RoomVersion, req.PrevEventIDs(), 100)
+	if err != nil {
+		return err
+	}
+	logrus.WithField("room_id", req.RoomID).Infof("backfilled %d events", len(events))
+
+	// persist these new events - auth checks have already been done
+	roomNID, backfilledEventMap := persistEvents(ctx, r.DB, events)
+	if err != nil {
+		return err
+	}
+
+	for _, ev := range backfilledEventMap {
+		// now add state for these events
+		stateIDs, ok := requester.eventIDToBeforeStateIDs[ev.EventID()]
+		if !ok {
+			// this should be impossible as all events returned must have pass Step 5 of the PDU checks
+			// which requires a list of state IDs.
+			logrus.WithError(err).WithField("event_id", ev.EventID()).Error("backfillViaFederation: failed to find state IDs for event which passed auth checks")
+			continue
+		}
+		var entries []types.StateEntry
+		if entries, err = r.DB.StateEntriesForEventIDs(ctx, stateIDs); err != nil {
+			// attempt to fetch the missing events
+			r.fetchAndStoreMissingEvents(ctx, info.RoomVersion, requester, stateIDs)
+			// try again
+			entries, err = r.DB.StateEntriesForEventIDs(ctx, stateIDs)
+			if err != nil {
+				logrus.WithError(err).WithField("event_id", ev.EventID()).Error("backfillViaFederation: failed to get state entries for event")
+				return err
+			}
+		}
+
+		var beforeStateSnapshotNID types.StateSnapshotNID
+		if beforeStateSnapshotNID, err = r.DB.AddState(ctx, roomNID, nil, entries); err != nil {
+			logrus.WithError(err).WithField("event_id", ev.EventID()).Error("backfillViaFederation: failed to persist state entries to get snapshot nid")
+			return err
+		}
+		if err = r.DB.SetState(ctx, ev.EventNID, beforeStateSnapshotNID); err != nil {
+			logrus.WithError(err).WithField("event_id", ev.EventID()).Error("backfillViaFederation: failed to persist snapshot nid")
+		}
+	}
+
+	// TODO: update backwards extremities, as that should be moved from syncapi to roomserver at some point.
+
+	res.Events = events
+	return nil
+}
+
+// fetchAndStoreMissingEvents does a best-effort fetch and store of missing events specified in stateIDs. Returns no error as it is just
+// best effort.
+func (r *Backfiller) fetchAndStoreMissingEvents(ctx context.Context, roomVer gomatrixserverlib.RoomVersion,
+	backfillRequester *backfillRequester, stateIDs []string) {
+
+	servers := backfillRequester.servers
+
+	// work out which are missing
+	nidMap, err := r.DB.EventNIDs(ctx, stateIDs)
+	if err != nil {
+		util.GetLogger(ctx).WithError(err).Warn("cannot query missing events")
+		return
+	}
+	missingMap := make(map[string]*gomatrixserverlib.HeaderedEvent) // id -> event
+	for _, id := range stateIDs {
+		if _, ok := nidMap[id]; !ok {
+			missingMap[id] = nil
+		}
+	}
+	util.GetLogger(ctx).Infof("Fetching %d missing state events (from %d possible servers)", len(missingMap), len(servers))
+
+	// fetch the events from federation. Loop the servers first so if we find one that works we stick with them
+	for _, srv := range servers {
+		for id, ev := range missingMap {
+			if ev != nil {
+				continue // already found
+			}
+			logger := util.GetLogger(ctx).WithField("server", srv).WithField("event_id", id)
+			res, err := r.FSAPI.GetEvent(ctx, srv, id)
+			if err != nil {
+				logger.WithError(err).Warn("failed to get event from server")
+				continue
+			}
+			loader := gomatrixserverlib.NewEventsLoader(roomVer, r.KeyRing, backfillRequester, backfillRequester.ProvideEvents, false)
+			result, err := loader.LoadAndVerify(ctx, res.PDUs, gomatrixserverlib.TopologicalOrderByPrevEvents)
+			if err != nil {
+				logger.WithError(err).Warn("failed to load and verify event")
+				continue
+			}
+			logger.Infof("returned %d PDUs which made events %+v", len(res.PDUs), result)
+			for _, res := range result {
+				if res.Error != nil {
+					logger.WithError(err).Warn("event failed PDU checks")
+					continue
+				}
+				missingMap[id] = res.Event
+			}
+		}
+	}
+
+	var newEvents []gomatrixserverlib.HeaderedEvent
+	for _, ev := range missingMap {
+		if ev != nil {
+			newEvents = append(newEvents, *ev)
+		}
+	}
+	util.GetLogger(ctx).Infof("Persisting %d new events", len(newEvents))
+	persistEvents(ctx, r.DB, newEvents)
+}
+
+// backfillRequester implements gomatrixserverlib.BackfillRequester
+type backfillRequester struct {
+	db         storage.Database
+	fsAPI      federationSenderAPI.FederationSenderInternalAPI
+	thisServer gomatrixserverlib.ServerName
+	bwExtrems  map[string][]string
+
+	// per-request state
+	servers                 []gomatrixserverlib.ServerName
+	eventIDToBeforeStateIDs map[string][]string
+	eventIDMap              map[string]gomatrixserverlib.Event
+}
+
+func newBackfillRequester(db storage.Database, fsAPI federationSenderAPI.FederationSenderInternalAPI, thisServer gomatrixserverlib.ServerName, bwExtrems map[string][]string) *backfillRequester {
+	return &backfillRequester{
+		db:                      db,
+		fsAPI:                   fsAPI,
+		thisServer:              thisServer,
+		eventIDToBeforeStateIDs: make(map[string][]string),
+		eventIDMap:              make(map[string]gomatrixserverlib.Event),
+		bwExtrems:               bwExtrems,
+	}
+}
+
+func (b *backfillRequester) StateIDsBeforeEvent(ctx context.Context, targetEvent gomatrixserverlib.HeaderedEvent) ([]string, error) {
+	b.eventIDMap[targetEvent.EventID()] = targetEvent.Unwrap()
+	if ids, ok := b.eventIDToBeforeStateIDs[targetEvent.EventID()]; ok {
+		return ids, nil
+	}
+	if len(targetEvent.PrevEventIDs()) == 0 && targetEvent.Type() == "m.room.create" && targetEvent.StateKeyEquals("") {
+		util.GetLogger(ctx).WithField("room_id", targetEvent.RoomID()).Info("Backfilled to the beginning of the room")
+		b.eventIDToBeforeStateIDs[targetEvent.EventID()] = []string{}
+		return nil, nil
+	}
+	// if we have exactly 1 prev event and we know the state of the room at that prev event, then just roll forward the prev event.
+	// Else, we have to hit /state_ids because either we don't know the state at all at this event (new backwards extremity) or
+	// we don't know the result of state res to merge forks (2 or more prev_events)
+	if len(targetEvent.PrevEventIDs()) == 1 {
+		prevEventID := targetEvent.PrevEventIDs()[0]
+		prevEvent, ok := b.eventIDMap[prevEventID]
+		if !ok {
+			goto FederationHit
+		}
+		prevEventStateIDs, ok := b.eventIDToBeforeStateIDs[prevEventID]
+		if !ok {
+			goto FederationHit
+		}
+		newStateIDs := b.calculateNewStateIDs(targetEvent.Unwrap(), prevEvent, prevEventStateIDs)
+		if newStateIDs != nil {
+			b.eventIDToBeforeStateIDs[targetEvent.EventID()] = newStateIDs
+			return newStateIDs, nil
+		}
+		// else we failed to calculate the new state, so fallthrough
+	}
+
+FederationHit:
+	var lastErr error
+	logrus.WithField("event_id", targetEvent.EventID()).Info("Requesting /state_ids at event")
+	for _, srv := range b.servers { // hit any valid server
+		c := gomatrixserverlib.FederatedStateProvider{
+			FedClient:          b.fsAPI,
+			RememberAuthEvents: false,
+			Server:             srv,
+		}
+		res, err := c.StateIDsBeforeEvent(ctx, targetEvent)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		b.eventIDToBeforeStateIDs[targetEvent.EventID()] = res
+		return res, nil
+	}
+	return nil, lastErr
+}
+
+func (b *backfillRequester) calculateNewStateIDs(targetEvent, prevEvent gomatrixserverlib.Event, prevEventStateIDs []string) []string {
+	newStateIDs := prevEventStateIDs[:]
+	if prevEvent.StateKey() == nil {
+		// state is the same as the previous event
+		b.eventIDToBeforeStateIDs[targetEvent.EventID()] = newStateIDs
+		return newStateIDs
+	}
+
+	missingState := false // true if we are missing the info for a state event ID
+	foundEvent := false   // true if we found a (type, state_key) match
+	// find which state ID to replace, if any
+	for i, id := range newStateIDs {
+		ev, ok := b.eventIDMap[id]
+		if !ok {
+			missingState = true
+			continue
+		}
+		// The state IDs BEFORE the target event are the state IDs BEFORE the prev_event PLUS the prev_event itself
+		if ev.Type() == prevEvent.Type() && ev.StateKeyEquals(*prevEvent.StateKey()) {
+			newStateIDs[i] = prevEvent.EventID()
+			foundEvent = true
+			break
+		}
+	}
+	if !foundEvent && !missingState {
+		// we can be certain that this is new state
+		newStateIDs = append(newStateIDs, prevEvent.EventID())
+		foundEvent = true
+	}
+
+	if foundEvent {
+		b.eventIDToBeforeStateIDs[targetEvent.EventID()] = newStateIDs
+		return newStateIDs
+	}
+	return nil
+}
+
+func (b *backfillRequester) StateBeforeEvent(ctx context.Context, roomVer gomatrixserverlib.RoomVersion,
+	event gomatrixserverlib.HeaderedEvent, eventIDs []string) (map[string]*gomatrixserverlib.Event, error) {
+
+	// try to fetch the events from the database first
+	events, err := b.ProvideEvents(roomVer, eventIDs)
+	if err != nil {
+		// non-fatal, fallthrough
+		logrus.WithError(err).Info("Failed to fetch events")
+	} else {
+		logrus.Infof("Fetched %d/%d events from the database", len(events), len(eventIDs))
+		if len(events) == len(eventIDs) {
+			result := make(map[string]*gomatrixserverlib.Event)
+			for i := range events {
+				result[events[i].EventID()] = &events[i]
+				b.eventIDMap[events[i].EventID()] = events[i]
+			}
+			return result, nil
+		}
+	}
+
+	c := gomatrixserverlib.FederatedStateProvider{
+		FedClient:          b.fsAPI,
+		RememberAuthEvents: false,
+		Server:             b.servers[0],
+	}
+	result, err := c.StateBeforeEvent(ctx, roomVer, event, eventIDs)
+	if err != nil {
+		return nil, err
+	}
+	for eventID, ev := range result {
+		b.eventIDMap[eventID] = *ev
+	}
+	return result, nil
+}
+
+// ServersAtEvent is called when trying to determine which server to request from.
+// It returns a list of servers which can be queried for backfill requests. These servers
+// will be servers that are in the room already. The entries at the beginning are preferred servers
+// and will be tried first. An empty list will fail the request.
+// nolint:gocyclo
+func (b *backfillRequester) ServersAtEvent(ctx context.Context, roomID, eventID string) []gomatrixserverlib.ServerName {
+	// eventID will be a prev_event ID of a backwards extremity, meaning we will not have a database entry for it. Instead, use
+	// its successor, so look it up.
+	successor := ""
+FindSuccessor:
+	for sucID, prevEventIDs := range b.bwExtrems {
+		for _, pe := range prevEventIDs {
+			if pe == eventID {
+				successor = sucID
+				break FindSuccessor
+			}
+		}
+	}
+	if successor == "" {
+		logrus.WithField("event_id", eventID).Error("ServersAtEvent: failed to find successor of this event to determine room state")
+		return nil
+	}
+	eventID = successor
+
+	// getMembershipsBeforeEventNID requires a NID, so retrieving the NID for
+	// the event is necessary.
+	NIDs, err := b.db.EventNIDs(ctx, []string{eventID})
+	if err != nil {
+		logrus.WithField("event_id", eventID).WithError(err).Error("ServersAtEvent: failed to get event NID for event")
+		return nil
+	}
+
+	info, err := b.db.RoomInfo(ctx, roomID)
+	if err != nil {
+		logrus.WithError(err).WithField("room_id", roomID).Error("ServersAtEvent: failed to get RoomInfo for room")
+		return nil
+	}
+	if info == nil || info.IsStub {
+		logrus.WithField("room_id", roomID).Error("ServersAtEvent: failed to get RoomInfo for room, room is missing")
+		return nil
+	}
+
+	stateEntries, err := helpers.StateBeforeEvent(ctx, b.db, *info, NIDs[eventID])
+	if err != nil {
+		logrus.WithField("event_id", eventID).WithError(err).Error("ServersAtEvent: failed to load state before event")
+		return nil
+	}
+
+	// possibly return all joined servers depending on history visiblity
+	memberEventsFromVis, err := joinEventsFromHistoryVisibility(ctx, b.db, roomID, stateEntries)
+	if err != nil {
+		logrus.WithError(err).Error("ServersAtEvent: failed calculate servers from history visibility rules")
+		return nil
+	}
+	logrus.Infof("ServersAtEvent including %d current events from history visibility", len(memberEventsFromVis))
+
+	// Retrieve all "m.room.member" state events of "join" membership, which
+	// contains the list of users in the room before the event, therefore all
+	// the servers in it at that moment.
+	memberEvents, err := helpers.GetMembershipsAtState(ctx, b.db, stateEntries, true)
+	if err != nil {
+		logrus.WithField("event_id", eventID).WithError(err).Error("ServersAtEvent: failed to get memberships before event")
+		return nil
+	}
+	memberEvents = append(memberEvents, memberEventsFromVis...)
+
+	// Store the server names in a temporary map to avoid duplicates.
+	serverSet := make(map[gomatrixserverlib.ServerName]bool)
+	for _, event := range memberEvents {
+		serverSet[event.Origin()] = true
+	}
+	var servers []gomatrixserverlib.ServerName
+	for server := range serverSet {
+		if server == b.thisServer {
+			continue
+		}
+		servers = append(servers, server)
+	}
+	b.servers = servers
+	return servers
+}
+
+// Backfill performs a backfill request to the given server.
+// https://matrix.org/docs/spec/server_server/latest#get-matrix-federation-v1-backfill-roomid
+func (b *backfillRequester) Backfill(ctx context.Context, server gomatrixserverlib.ServerName, roomID string,
+	limit int, fromEventIDs []string) (gomatrixserverlib.Transaction, error) {
+
+	tx, err := b.fsAPI.Backfill(ctx, server, roomID, limit, fromEventIDs)
+	return tx, err
+}
+
+func (b *backfillRequester) ProvideEvents(roomVer gomatrixserverlib.RoomVersion, eventIDs []string) ([]gomatrixserverlib.Event, error) {
+	ctx := context.Background()
+	nidMap, err := b.db.EventNIDs(ctx, eventIDs)
+	if err != nil {
+		logrus.WithError(err).WithField("event_ids", eventIDs).Error("Failed to find events")
+		return nil, err
+	}
+	eventNIDs := make([]types.EventNID, len(nidMap))
+	i := 0
+	for _, nid := range nidMap {
+		eventNIDs[i] = nid
+		i++
+	}
+	eventsWithNids, err := b.db.Events(ctx, eventNIDs)
+	if err != nil {
+		logrus.WithError(err).WithField("event_nids", eventNIDs).Error("Failed to load events")
+		return nil, err
+	}
+	events := make([]gomatrixserverlib.Event, len(eventsWithNids))
+	for i := range eventsWithNids {
+		events[i] = eventsWithNids[i].Event
+	}
+	return events, nil
+}
+
+// joinEventsFromHistoryVisibility returns all CURRENTLY joined members if the provided state indicated a 'shared' history visibility.
+// TODO: Long term we probably want a history_visibility table which stores eventNID | visibility_enum so we can just
+//       pull all events and then filter by that table.
+func joinEventsFromHistoryVisibility(
+	ctx context.Context, db storage.Database, roomID string, stateEntries []types.StateEntry) ([]types.Event, error) {
+
+	var eventNIDs []types.EventNID
+	for _, entry := range stateEntries {
+		// Filter the events to retrieve to only keep the membership events
+		if entry.EventTypeNID == types.MRoomHistoryVisibilityNID && entry.EventStateKeyNID == types.EmptyStateKeyNID {
+			eventNIDs = append(eventNIDs, entry.EventNID)
+			break
+		}
+	}
+
+	// Get all of the events in this state
+	stateEvents, err := db.Events(ctx, eventNIDs)
+	if err != nil {
+		return nil, err
+	}
+	events := make([]gomatrixserverlib.Event, len(stateEvents))
+	for i := range stateEvents {
+		events[i] = stateEvents[i].Event
+	}
+	visibility := auth.HistoryVisibilityForRoom(events)
+	if visibility != "shared" {
+		logrus.Infof("ServersAtEvent history visibility not shared: %s", visibility)
+		return nil, nil
+	}
+	// get joined members
+	info, err := db.RoomInfo(ctx, roomID)
+	if err != nil {
+		return nil, err
+	}
+	joinEventNIDs, err := db.GetMembershipEventNIDsForRoom(ctx, info.RoomNID, true, false)
+	if err != nil {
+		return nil, err
+	}
+	return db.Events(ctx, joinEventNIDs)
+}
+
+func persistEvents(ctx context.Context, db storage.Database, events []gomatrixserverlib.HeaderedEvent) (types.RoomNID, map[string]types.Event) {
+	var roomNID types.RoomNID
+	backfilledEventMap := make(map[string]types.Event)
+	for j, ev := range events {
+		nidMap, err := db.EventNIDs(ctx, ev.AuthEventIDs())
+		if err != nil { // this shouldn't happen as RequestBackfill already found them
+			logrus.WithError(err).WithField("auth_events", ev.AuthEventIDs()).Error("Failed to find one or more auth events")
+			continue
+		}
+		authNids := make([]types.EventNID, len(nidMap))
+		i := 0
+		for _, nid := range nidMap {
+			authNids[i] = nid
+			i++
+		}
+		var stateAtEvent types.StateAtEvent
+		var redactedEventID string
+		var redactionEvent *gomatrixserverlib.Event
+		roomNID, stateAtEvent, redactionEvent, redactedEventID, err = db.StoreEvent(ctx, ev.Unwrap(), nil, authNids)
+		if err != nil {
+			logrus.WithError(err).WithField("event_id", ev.EventID()).Error("Failed to persist event")
+			continue
+		}
+		// If storing this event results in it being redacted, then do so.
+		// It's also possible for this event to be a redaction which results in another event being
+		// redacted, which we don't care about since we aren't returning it in this backfill.
+		if redactedEventID == ev.EventID() {
+			eventToRedact := ev.Unwrap()
+			redactedEvent, err := eventutil.RedactEvent(redactionEvent, &eventToRedact)
+			if err != nil {
+				logrus.WithError(err).WithField("event_id", ev.EventID()).Error("Failed to redact event")
+				continue
+			}
+			ev = redactedEvent.Headered(ev.RoomVersion)
+			events[j] = ev
+		}
+		backfilledEventMap[ev.EventID()] = types.Event{
+			EventNID: stateAtEvent.StateEntry.EventNID,
+			Event:    ev.Unwrap(),
+		}
+	}
+	return roomNID, backfilledEventMap
+}

roomserver/internal/perform/perform_invite.go

@@ -1,11 +1,28 @@
-package internal
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package perform
 
 import (
 	"context"
 	"fmt"
 
 	federationSenderAPI "github.com/matrix-org/dendrite/federationsender/api"
+	"github.com/matrix-org/dendrite/internal/config"
 	"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/state"
 	"github.com/matrix-org/dendrite/roomserver/storage"
 	"github.com/matrix-org/dendrite/roomserver/types"
@@ -13,22 +30,29 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+type Inviter struct {
+	DB      storage.Database
+	Cfg     *config.RoomServer
+	FSAPI   federationSenderAPI.FederationSenderInternalAPI
+	Inputer *input.Inputer
+}
+
 // nolint:gocyclo
-func (r *RoomserverInternalAPI) PerformInvite(
+func (r *Inviter) PerformInvite(
 	ctx context.Context,
 	req *api.PerformInviteRequest,
 	res *api.PerformInviteResponse,
-) error {
+) ([]api.OutputEvent, error) {
 	event := req.Event
 	if event.StateKey() == nil {
-		return fmt.Errorf("invite must be a state event")
+		return nil, fmt.Errorf("invite must be a state event")
 	}
 
 	roomID := event.RoomID()
 	targetUserID := *event.StateKey()
 	info, err := r.DB.RoomInfo(ctx, roomID)
 	if err != nil {
-		return fmt.Errorf("Failed to load RoomInfo: %w", err)
+		return nil, fmt.Errorf("Failed to load RoomInfo: %w", err)
 	}
 
 	log.WithFields(log.Fields{
@@ -52,11 +76,11 @@ func (r *RoomserverInternalAPI) PerformInvite(
 	}
 	if len(inviteState) == 0 {
 		if err = event.SetUnsignedField("invite_room_state", struct{}{}); err != nil {
-			return fmt.Errorf("event.SetUnsignedField: %w", err)
+			return nil, fmt.Errorf("event.SetUnsignedField: %w", err)
 		}
 	} else {
 		if err = event.SetUnsignedField("invite_room_state", inviteState); err != nil {
-			return fmt.Errorf("event.SetUnsignedField: %w", err)
+			return nil, fmt.Errorf("event.SetUnsignedField: %w", err)
 		}
 	}
 
@@ -64,7 +88,7 @@ func (r *RoomserverInternalAPI) PerformInvite(
 	if info != nil {
 		_, isAlreadyJoined, err = r.DB.GetMembership(ctx, info.RoomNID, *event.StateKey())
 		if err != nil {
-			return fmt.Errorf("r.DB.GetMembership: %w", err)
+			return nil, fmt.Errorf("r.DB.GetMembership: %w", err)
 		}
 	}
 	if isAlreadyJoined {
@@ -99,7 +123,7 @@ func (r *RoomserverInternalAPI) PerformInvite(
 			Code: api.PerformErrorNotAllowed,
 			Msg:  "User is already joined to room",
 		}
-		return nil
+		return nil, nil
 	}
 
 	if isOriginLocal {
@@ -107,7 +131,7 @@ func (r *RoomserverInternalAPI) PerformInvite(
 		// try and see if the user is allowed to make this invite. We can't do
 		// this for invites coming in over federation - we have to take those on
 		// trust.
-		_, err = checkAuthEvents(ctx, r.DB, event, event.AuthEventIDs())
+		_, err = helpers.CheckAuthEvents(ctx, r.DB, event, event.AuthEventIDs())
 		if err != nil {
 			log.WithError(err).WithField("event_id", event.EventID()).WithField("auth_event_ids", event.AuthEventIDs()).Error(
 				"processInviteEvent.checkAuthEvents failed for event",
@@ -117,9 +141,9 @@ func (r *RoomserverInternalAPI) PerformInvite(
 					Msg:  err.Error(),
 					Code: api.PerformErrorNotAllowed,
 				}
-				return nil
+				return nil, nil
 			}
-			return fmt.Errorf("checkAuthEvents: %w", err)
+			return nil, fmt.Errorf("checkAuthEvents: %w", err)
 		}
 
 		// If the invite originated from us and the target isn't local then we
@@ -133,13 +157,13 @@ func (r *RoomserverInternalAPI) PerformInvite(
 				InviteRoomState: inviteState,
 			}
 			fsRes := &federationSenderAPI.PerformInviteResponse{}
-			if err = r.fsAPI.PerformInvite(ctx, fsReq, fsRes); err != nil {
+			if err = r.FSAPI.PerformInvite(ctx, fsReq, fsRes); err != nil {
 				res.Error = &api.PerformError{
 					Msg:  err.Error(),
 					Code: api.PerformErrorNoOperation,
 				}
-				log.WithError(err).WithField("event_id", event.EventID()).Error("r.fsAPI.PerformInvite failed")
-				return nil
+				log.WithError(err).WithField("event_id", event.EventID()).Error("r.FSAPI.PerformInvite failed")
+				return nil, nil
 			}
 			event = fsRes.Event
 		}
@@ -159,8 +183,8 @@ func (r *RoomserverInternalAPI) PerformInvite(
 			},
 		}
 		inputRes := &api.InputRoomEventsResponse{}
-		if err = r.InputRoomEvents(context.Background(), inputReq, inputRes); err != nil {
-			return fmt.Errorf("r.InputRoomEvents: %w", err)
+		if err = r.Inputer.InputRoomEvents(context.Background(), inputReq, inputRes); err != nil {
+			return nil, fmt.Errorf("r.InputRoomEvents: %w", err)
 		}
 	} else {
 		// The invite originated over federation. Process the membership
@@ -168,25 +192,23 @@ func (r *RoomserverInternalAPI) PerformInvite(
 		// invite.
 		updater, err := r.DB.MembershipUpdater(ctx, roomID, targetUserID, isTargetLocal, req.RoomVersion)
 		if err != nil {
-			return fmt.Errorf("r.DB.MembershipUpdater: %w", err)
+			return nil, fmt.Errorf("r.DB.MembershipUpdater: %w", err)
 		}
 
 		unwrapped := event.Unwrap()
-		outputUpdates, err := updateToInviteMembership(updater, &unwrapped, nil, req.Event.RoomVersion)
+		outputUpdates, err := helpers.UpdateToInviteMembership(updater, &unwrapped, nil, req.Event.RoomVersion)
 		if err != nil {
-			return fmt.Errorf("updateToInviteMembership: %w", err)
+			return nil, fmt.Errorf("updateToInviteMembership: %w", err)
 		}
 
 		if err = updater.Commit(); err != nil {
-			return fmt.Errorf("updater.Commit: %w", err)
+			return nil, fmt.Errorf("updater.Commit: %w", err)
 		}
 
-		if err = r.WriteOutputEvents(roomID, outputUpdates); err != nil {
-			return fmt.Errorf("r.WriteOutputEvents: %w", err)
-		}
+		return outputUpdates, nil
 	}
 
-	return nil
+	return nil, nil
 }
 
 func buildInviteStrippedState(
@@ -208,7 +230,7 @@ func buildInviteStrippedState(
 			StateKey:  "",
 		})
 	}
-	roomState := state.NewStateResolution(db)
+	roomState := state.NewStateResolution(db, *info)
 	stateEntries, err := roomState.LoadStateAtSnapshotForStringTuples(
 		ctx, info.StateSnapshotNID, stateWanted,
 	)

roomserver/internal/perform/perform_join.go

@@ -1,4 +1,18 @@
-package internal
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package perform
 
 import (
 	"context"
@@ -8,14 +22,27 @@ import (
 	"time"
 
 	fsAPI "github.com/matrix-org/dendrite/federationsender/api"
+	"github.com/matrix-org/dendrite/internal/config"
 	"github.com/matrix-org/dendrite/internal/eventutil"
 	"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/storage"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/sirupsen/logrus"
 )
 
+type Joiner struct {
+	ServerName gomatrixserverlib.ServerName
+	Cfg        *config.RoomServer
+	FSAPI      fsAPI.FederationSenderInternalAPI
+	DB         storage.Database
+
+	Inputer *input.Inputer
+}
+
 // PerformJoin handles joining matrix rooms, including over federation by talking to the federationsender.
-func (r *RoomserverInternalAPI) PerformJoin(
+func (r *Joiner) PerformJoin(
 	ctx context.Context,
 	req *api.PerformJoinRequest,
 	res *api.PerformJoinResponse,
@@ -34,7 +61,7 @@ func (r *RoomserverInternalAPI) PerformJoin(
 	res.RoomID = roomID
 }
 
-func (r *RoomserverInternalAPI) performJoin(
+func (r *Joiner) performJoin(
 	ctx context.Context,
 	req *api.PerformJoinRequest,
 ) (string, error) {
@@ -63,7 +90,7 @@ func (r *RoomserverInternalAPI) performJoin(
 	}
 }
 
-func (r *RoomserverInternalAPI) performJoinRoomByAlias(
+func (r *Joiner) performJoinRoomByAlias(
 	ctx context.Context,
 	req *api.PerformJoinRequest,
 ) (string, error) {
@@ -85,7 +112,7 @@ func (r *RoomserverInternalAPI) performJoinRoomByAlias(
 			ServerName: domain,            // the server to ask
 		}
 		dirRes := fsAPI.PerformDirectoryLookupResponse{}
-		err = r.fsAPI.PerformDirectoryLookup(ctx, &dirReq, &dirRes)
+		err = r.FSAPI.PerformDirectoryLookup(ctx, &dirReq, &dirRes)
 		if err != nil {
 			logrus.WithError(err).Errorf("error looking up alias %q", req.RoomIDOrAlias)
 			return "", fmt.Errorf("Looking up alias %q over federation failed: %w", req.RoomIDOrAlias, err)
@@ -112,7 +139,7 @@ func (r *RoomserverInternalAPI) performJoinRoomByAlias(
 
 // TODO: Break this function up a bit
 // nolint:gocyclo
-func (r *RoomserverInternalAPI) performJoinRoomByID(
+func (r *Joiner) performJoinRoomByID(
 	ctx context.Context,
 	req *api.PerformJoinRequest,
 ) (string, error) {
@@ -161,8 +188,8 @@ func (r *RoomserverInternalAPI) performJoinRoomByID(
 	// where we might think we know about a room in the following
 	// section but don't know the latest state as all of our users
 	// have left.
-	serverInRoom, _ := r.isServerCurrentlyInRoom(ctx, r.ServerName, req.RoomIDOrAlias)
-	isInvitePending, inviteSender, _, err := r.isInvitePending(ctx, req.RoomIDOrAlias, req.UserID)
+	serverInRoom, _ := helpers.IsServerCurrentlyInRoom(ctx, r.DB, r.ServerName, req.RoomIDOrAlias)
+	isInvitePending, inviteSender, _, err := helpers.IsInvitePending(ctx, r.DB, req.RoomIDOrAlias, req.UserID)
 	if err == nil && isInvitePending && !serverInRoom {
 		// Check if there's an invite pending.
 		_, inviterDomain, ierr := gomatrixserverlib.SplitID('@', inviteSender)
@@ -188,15 +215,7 @@ func (r *RoomserverInternalAPI) performJoinRoomByID(
 	// locally on the homeserver.
 	// TODO: Check what happens if the room exists on the server
 	// but everyone has since left. I suspect it does the wrong thing.
-	buildRes := api.QueryLatestEventsAndStateResponse{}
-	event, err := eventutil.BuildEvent(
-		ctx,          // the request context
-		&eb,          // the template join event
-		r.Cfg.Matrix, // the server configuration
-		time.Now(),   // the event timestamp to use
-		r,            // the roomserver API to use
-		&buildRes,    // the query response
-	)
+	event, buildRes, err := buildEvent(ctx, r.DB, r.Cfg.Matrix, &eb)
 
 	switch err {
 	case nil:
@@ -228,7 +247,7 @@ func (r *RoomserverInternalAPI) performJoinRoomByID(
 				},
 			}
 			inputRes := api.InputRoomEventsResponse{}
-			if err = r.InputRoomEvents(ctx, &inputReq, &inputRes); err != nil {
+			if err = r.Inputer.InputRoomEvents(ctx, &inputReq, &inputRes); err != nil {
 				var notAllowed *gomatrixserverlib.NotAllowed
 				if errors.As(err, &notAllowed) {
 					return "", &api.PerformError{
@@ -271,7 +290,7 @@ func (r *RoomserverInternalAPI) performJoinRoomByID(
 	return req.RoomIDOrAlias, nil
 }
 
-func (r *RoomserverInternalAPI) performFederatedJoinRoomByID(
+func (r *Joiner) performFederatedJoinRoomByID(
 	ctx context.Context,
 	req *api.PerformJoinRequest,
 ) error {
@@ -283,7 +302,7 @@ func (r *RoomserverInternalAPI) performFederatedJoinRoomByID(
 		Content:     req.Content,       // the membership event content
 	}
 	fedRes := fsAPI.PerformJoinResponse{}
-	r.fsAPI.PerformJoin(ctx, &fedReq, &fedRes)
+	r.FSAPI.PerformJoin(ctx, &fedReq, &fedRes)
 	if fedRes.LastError != nil {
 		return &api.PerformError{
 			Code:       api.PerformErrRemote,
@@ -293,3 +312,31 @@ func (r *RoomserverInternalAPI) performFederatedJoinRoomByID(
 	}
 	return nil
 }
+
+func buildEvent(
+	ctx context.Context, db storage.Database, cfg *config.Global, builder *gomatrixserverlib.EventBuilder,
+) (*gomatrixserverlib.HeaderedEvent, *api.QueryLatestEventsAndStateResponse, error) {
+	eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(builder)
+	if err != nil {
+		return nil, nil, fmt.Errorf("gomatrixserverlib.StateNeededForEventBuilder: %w", err)
+	}
+
+	if len(eventsNeeded.Tuples()) == 0 {
+		return nil, nil, errors.New("expecting state tuples for event builder, got none")
+	}
+
+	var queryRes api.QueryLatestEventsAndStateResponse
+	err = helpers.QueryLatestEventsAndState(ctx, db, &api.QueryLatestEventsAndStateRequest{
+		RoomID:       builder.RoomID,
+		StateToFetch: eventsNeeded.Tuples(),
+	}, &queryRes)
+	if err != nil {
+		return nil, nil, fmt.Errorf("QueryLatestEventsAndState: %w", err)
+	}
+
+	ev, err := eventutil.BuildEvent(ctx, builder, cfg, time.Now(), &eventsNeeded, &queryRes)
+	if err != nil {
+		return nil, nil, err
+	}
+	return ev, &queryRes, nil
+}

roomserver/internal/perform/perform_leave.go

@@ -0,0 +1,183 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package perform
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	fsAPI "github.com/matrix-org/dendrite/federationsender/api"
+	"github.com/matrix-org/dendrite/internal/config"
+	"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/storage"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+type Leaver struct {
+	Cfg   *config.RoomServer
+	DB    storage.Database
+	FSAPI fsAPI.FederationSenderInternalAPI
+
+	Inputer *input.Inputer
+}
+
+// WriteOutputEvents implements OutputRoomEventWriter
+func (r *Leaver) PerformLeave(
+	ctx context.Context,
+	req *api.PerformLeaveRequest,
+	res *api.PerformLeaveResponse,
+) ([]api.OutputEvent, error) {
+	_, domain, err := gomatrixserverlib.SplitID('@', req.UserID)
+	if err != nil {
+		return nil, fmt.Errorf("Supplied user ID %q in incorrect format", req.UserID)
+	}
+	if domain != r.Cfg.Matrix.ServerName {
+		return nil, fmt.Errorf("User %q does not belong to this homeserver", req.UserID)
+	}
+	if strings.HasPrefix(req.RoomID, "!") {
+		return r.performLeaveRoomByID(ctx, req, res)
+	}
+	return nil, fmt.Errorf("Room ID %q is invalid", req.RoomID)
+}
+
+func (r *Leaver) performLeaveRoomByID(
+	ctx context.Context,
+	req *api.PerformLeaveRequest,
+	res *api.PerformLeaveResponse, // nolint:unparam
+) ([]api.OutputEvent, error) {
+	// If there's an invite outstanding for the room then respond to
+	// that.
+	isInvitePending, senderUser, eventID, err := helpers.IsInvitePending(ctx, r.DB, req.RoomID, req.UserID)
+	if err == nil && isInvitePending {
+		return r.performRejectInvite(ctx, req, res, senderUser, eventID)
+	}
+
+	// There's no invite pending, so first of all we want to find out
+	// if the room exists and if the user is actually in it.
+	latestReq := api.QueryLatestEventsAndStateRequest{
+		RoomID: req.RoomID,
+		StateToFetch: []gomatrixserverlib.StateKeyTuple{
+			{
+				EventType: gomatrixserverlib.MRoomMember,
+				StateKey:  req.UserID,
+			},
+		},
+	}
+	latestRes := api.QueryLatestEventsAndStateResponse{}
+	if err = helpers.QueryLatestEventsAndState(ctx, r.DB, &latestReq, &latestRes); err != nil {
+		return nil, err
+	}
+	if !latestRes.RoomExists {
+		return nil, fmt.Errorf("Room %q does not exist", req.RoomID)
+	}
+
+	// Now let's see if the user is in the room.
+	if len(latestRes.StateEvents) == 0 {
+		return nil, fmt.Errorf("User %q is not a member of room %q", req.UserID, req.RoomID)
+	}
+	membership, err := latestRes.StateEvents[0].Membership()
+	if err != nil {
+		return nil, fmt.Errorf("Error getting membership: %w", err)
+	}
+	if membership != gomatrixserverlib.Join {
+		// TODO: should be able to handle "invite" in this case too, if
+		// it's a case of kicking or banning or such
+		return nil, fmt.Errorf("User %q is not joined to the room (membership is %q)", req.UserID, membership)
+	}
+
+	// Prepare the template for the leave event.
+	userID := req.UserID
+	eb := gomatrixserverlib.EventBuilder{
+		Type:     gomatrixserverlib.MRoomMember,
+		Sender:   userID,
+		StateKey: &userID,
+		RoomID:   req.RoomID,
+		Redacts:  "",
+	}
+	if err = eb.SetContent(map[string]interface{}{"membership": "leave"}); err != nil {
+		return nil, fmt.Errorf("eb.SetContent: %w", err)
+	}
+	if err = eb.SetUnsigned(struct{}{}); err != nil {
+		return nil, fmt.Errorf("eb.SetUnsigned: %w", err)
+	}
+
+	// We know that the user is in the room at this point so let's build
+	// a leave event.
+	// TODO: Check what happens if the room exists on the server
+	// but everyone has since left. I suspect it does the wrong thing.
+	event, buildRes, err := buildEvent(ctx, r.DB, r.Cfg.Matrix, &eb)
+	if err != nil {
+		return nil, fmt.Errorf("eventutil.BuildEvent: %w", err)
+	}
+
+	// Give our leave event to the roomserver input stream. The
+	// roomserver will process the membership change and notify
+	// downstream automatically.
+	inputReq := api.InputRoomEventsRequest{
+		InputRoomEvents: []api.InputRoomEvent{
+			{
+				Kind:         api.KindNew,
+				Event:        event.Headered(buildRes.RoomVersion),
+				AuthEventIDs: event.AuthEventIDs(),
+				SendAsServer: string(r.Cfg.Matrix.ServerName),
+			},
+		},
+	}
+	inputRes := api.InputRoomEventsResponse{}
+	if err = r.Inputer.InputRoomEvents(ctx, &inputReq, &inputRes); err != nil {
+		return nil, fmt.Errorf("r.InputRoomEvents: %w", err)
+	}
+
+	return nil, nil
+}
+
+func (r *Leaver) performRejectInvite(
+	ctx context.Context,
+	req *api.PerformLeaveRequest,
+	res *api.PerformLeaveResponse, // nolint:unparam
+	senderUser, eventID string,
+) ([]api.OutputEvent, error) {
+	_, domain, err := gomatrixserverlib.SplitID('@', senderUser)
+	if err != nil {
+		return nil, fmt.Errorf("User ID %q invalid: %w", senderUser, err)
+	}
+
+	// Ask the federation sender to perform a federated leave for us.
+	leaveReq := fsAPI.PerformLeaveRequest{
+		RoomID:      req.RoomID,
+		UserID:      req.UserID,
+		ServerNames: []gomatrixserverlib.ServerName{domain},
+	}
+	leaveRes := fsAPI.PerformLeaveResponse{}
+	if err := r.FSAPI.PerformLeave(ctx, &leaveReq, &leaveRes); err != nil {
+		return nil, err
+	}
+
+	// Withdraw the invite, so that the sync API etc are
+	// notified that we rejected it.
+	return []api.OutputEvent{
+		{
+			Type: api.OutputTypeRetireInviteEvent,
+			RetireInviteEvent: &api.OutputRetireInviteEvent{
+				EventID:      eventID,
+				Membership:   "leave",
+				TargetUserID: req.UserID,
+			},
+		},
+	}, nil
+}

roomserver/internal/perform/perform_publish.go

@@ -0,0 +1,39 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package perform
+
+import (
+	"context"
+
+	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/roomserver/storage"
+)
+
+type Publisher struct {
+	DB storage.Database
+}
+
+func (r *Publisher) PerformPublish(
+	ctx context.Context,
+	req *api.PerformPublishRequest,
+	res *api.PerformPublishResponse,
+) {
+	err := r.DB.PublishRoom(ctx, req.RoomID, req.Visibility == "public")
+	if err != nil {
+		res.Error = &api.PerformError{
+			Msg: err.Error(),
+		}
+	}
+}

roomserver/internal/perform_backfill.go

@@ -1,305 +0,0 @@
-package internal
-
-import (
-	"context"
-
-	"github.com/matrix-org/dendrite/roomserver/auth"
-	"github.com/matrix-org/dendrite/roomserver/storage"
-	"github.com/matrix-org/dendrite/roomserver/types"
-	"github.com/matrix-org/gomatrixserverlib"
-	"github.com/matrix-org/util"
-	"github.com/sirupsen/logrus"
-)
-
-// backfillRequester implements gomatrixserverlib.BackfillRequester
-type backfillRequester struct {
-	db         storage.Database
-	fedClient  *gomatrixserverlib.FederationClient
-	thisServer gomatrixserverlib.ServerName
-	bwExtrems  map[string][]string
-
-	// per-request state
-	servers                 []gomatrixserverlib.ServerName
-	eventIDToBeforeStateIDs map[string][]string
-	eventIDMap              map[string]gomatrixserverlib.Event
-}
-
-func newBackfillRequester(db storage.Database, fedClient *gomatrixserverlib.FederationClient, thisServer gomatrixserverlib.ServerName, bwExtrems map[string][]string) *backfillRequester {
-	return &backfillRequester{
-		db:                      db,
-		fedClient:               fedClient,
-		thisServer:              thisServer,
-		eventIDToBeforeStateIDs: make(map[string][]string),
-		eventIDMap:              make(map[string]gomatrixserverlib.Event),
-		bwExtrems:               bwExtrems,
-	}
-}
-
-func (b *backfillRequester) StateIDsBeforeEvent(ctx context.Context, targetEvent gomatrixserverlib.HeaderedEvent) ([]string, error) {
-	b.eventIDMap[targetEvent.EventID()] = targetEvent.Unwrap()
-	if ids, ok := b.eventIDToBeforeStateIDs[targetEvent.EventID()]; ok {
-		return ids, nil
-	}
-	if len(targetEvent.PrevEventIDs()) == 0 && targetEvent.Type() == "m.room.create" && targetEvent.StateKeyEquals("") {
-		util.GetLogger(ctx).WithField("room_id", targetEvent.RoomID()).Info("Backfilled to the beginning of the room")
-		b.eventIDToBeforeStateIDs[targetEvent.EventID()] = []string{}
-		return nil, nil
-	}
-	// if we have exactly 1 prev event and we know the state of the room at that prev event, then just roll forward the prev event.
-	// Else, we have to hit /state_ids because either we don't know the state at all at this event (new backwards extremity) or
-	// we don't know the result of state res to merge forks (2 or more prev_events)
-	if len(targetEvent.PrevEventIDs()) == 1 {
-		prevEventID := targetEvent.PrevEventIDs()[0]
-		prevEvent, ok := b.eventIDMap[prevEventID]
-		if !ok {
-			goto FederationHit
-		}
-		prevEventStateIDs, ok := b.eventIDToBeforeStateIDs[prevEventID]
-		if !ok {
-			goto FederationHit
-		}
-		newStateIDs := b.calculateNewStateIDs(targetEvent.Unwrap(), prevEvent, prevEventStateIDs)
-		if newStateIDs != nil {
-			b.eventIDToBeforeStateIDs[targetEvent.EventID()] = newStateIDs
-			return newStateIDs, nil
-		}
-		// else we failed to calculate the new state, so fallthrough
-	}
-
-FederationHit:
-	var lastErr error
-	logrus.WithField("event_id", targetEvent.EventID()).Info("Requesting /state_ids at event")
-	for _, srv := range b.servers { // hit any valid server
-		c := gomatrixserverlib.FederatedStateProvider{
-			FedClient:          b.fedClient,
-			RememberAuthEvents: false,
-			Server:             srv,
-		}
-		res, err := c.StateIDsBeforeEvent(ctx, targetEvent)
-		if err != nil {
-			lastErr = err
-			continue
-		}
-		b.eventIDToBeforeStateIDs[targetEvent.EventID()] = res
-		return res, nil
-	}
-	return nil, lastErr
-}
-
-func (b *backfillRequester) calculateNewStateIDs(targetEvent, prevEvent gomatrixserverlib.Event, prevEventStateIDs []string) []string {
-	newStateIDs := prevEventStateIDs[:]
-	if prevEvent.StateKey() == nil {
-		// state is the same as the previous event
-		b.eventIDToBeforeStateIDs[targetEvent.EventID()] = newStateIDs
-		return newStateIDs
-	}
-
-	missingState := false // true if we are missing the info for a state event ID
-	foundEvent := false   // true if we found a (type, state_key) match
-	// find which state ID to replace, if any
-	for i, id := range newStateIDs {
-		ev, ok := b.eventIDMap[id]
-		if !ok {
-			missingState = true
-			continue
-		}
-		// The state IDs BEFORE the target event are the state IDs BEFORE the prev_event PLUS the prev_event itself
-		if ev.Type() == prevEvent.Type() && ev.StateKeyEquals(*prevEvent.StateKey()) {
-			newStateIDs[i] = prevEvent.EventID()
-			foundEvent = true
-			break
-		}
-	}
-	if !foundEvent && !missingState {
-		// we can be certain that this is new state
-		newStateIDs = append(newStateIDs, prevEvent.EventID())
-		foundEvent = true
-	}
-
-	if foundEvent {
-		b.eventIDToBeforeStateIDs[targetEvent.EventID()] = newStateIDs
-		return newStateIDs
-	}
-	return nil
-}
-
-func (b *backfillRequester) StateBeforeEvent(ctx context.Context, roomVer gomatrixserverlib.RoomVersion,
-	event gomatrixserverlib.HeaderedEvent, eventIDs []string) (map[string]*gomatrixserverlib.Event, error) {
-
-	// try to fetch the events from the database first
-	events, err := b.ProvideEvents(roomVer, eventIDs)
-	if err != nil {
-		// non-fatal, fallthrough
-		logrus.WithError(err).Info("Failed to fetch events")
-	} else {
-		logrus.Infof("Fetched %d/%d events from the database", len(events), len(eventIDs))
-		if len(events) == len(eventIDs) {
-			result := make(map[string]*gomatrixserverlib.Event)
-			for i := range events {
-				result[events[i].EventID()] = &events[i]
-				b.eventIDMap[events[i].EventID()] = events[i]
-			}
-			return result, nil
-		}
-	}
-
-	c := gomatrixserverlib.FederatedStateProvider{
-		FedClient:          b.fedClient,
-		RememberAuthEvents: false,
-		Server:             b.servers[0],
-	}
-	result, err := c.StateBeforeEvent(ctx, roomVer, event, eventIDs)
-	if err != nil {
-		return nil, err
-	}
-	for eventID, ev := range result {
-		b.eventIDMap[eventID] = *ev
-	}
-	return result, nil
-}
-
-// ServersAtEvent is called when trying to determine which server to request from.
-// It returns a list of servers which can be queried for backfill requests. These servers
-// will be servers that are in the room already. The entries at the beginning are preferred servers
-// and will be tried first. An empty list will fail the request.
-func (b *backfillRequester) ServersAtEvent(ctx context.Context, roomID, eventID string) []gomatrixserverlib.ServerName {
-	// eventID will be a prev_event ID of a backwards extremity, meaning we will not have a database entry for it. Instead, use
-	// its successor, so look it up.
-	successor := ""
-FindSuccessor:
-	for sucID, prevEventIDs := range b.bwExtrems {
-		for _, pe := range prevEventIDs {
-			if pe == eventID {
-				successor = sucID
-				break FindSuccessor
-			}
-		}
-	}
-	if successor == "" {
-		logrus.WithField("event_id", eventID).Error("ServersAtEvent: failed to find successor of this event to determine room state")
-		return nil
-	}
-	eventID = successor
-
-	// getMembershipsBeforeEventNID requires a NID, so retrieving the NID for
-	// the event is necessary.
-	NIDs, err := b.db.EventNIDs(ctx, []string{eventID})
-	if err != nil {
-		logrus.WithField("event_id", eventID).WithError(err).Error("ServersAtEvent: failed to get event NID for event")
-		return nil
-	}
-
-	stateEntries, err := stateBeforeEvent(ctx, b.db, NIDs[eventID])
-	if err != nil {
-		logrus.WithField("event_id", eventID).WithError(err).Error("ServersAtEvent: failed to load state before event")
-		return nil
-	}
-
-	// possibly return all joined servers depending on history visiblity
-	memberEventsFromVis, err := joinEventsFromHistoryVisibility(ctx, b.db, roomID, stateEntries)
-	if err != nil {
-		logrus.WithError(err).Error("ServersAtEvent: failed calculate servers from history visibility rules")
-		return nil
-	}
-	logrus.Infof("ServersAtEvent including %d current events from history visibility", len(memberEventsFromVis))
-
-	// Retrieve all "m.room.member" state events of "join" membership, which
-	// contains the list of users in the room before the event, therefore all
-	// the servers in it at that moment.
-	memberEvents, err := getMembershipsAtState(ctx, b.db, stateEntries, true)
-	if err != nil {
-		logrus.WithField("event_id", eventID).WithError(err).Error("ServersAtEvent: failed to get memberships before event")
-		return nil
-	}
-	memberEvents = append(memberEvents, memberEventsFromVis...)
-
-	// Store the server names in a temporary map to avoid duplicates.
-	serverSet := make(map[gomatrixserverlib.ServerName]bool)
-	for _, event := range memberEvents {
-		serverSet[event.Origin()] = true
-	}
-	var servers []gomatrixserverlib.ServerName
-	for server := range serverSet {
-		if server == b.thisServer {
-			continue
-		}
-		servers = append(servers, server)
-	}
-	b.servers = servers
-	return servers
-}
-
-// Backfill performs a backfill request to the given server.
-// https://matrix.org/docs/spec/server_server/latest#get-matrix-federation-v1-backfill-roomid
-func (b *backfillRequester) Backfill(ctx context.Context, server gomatrixserverlib.ServerName, roomID string,
-	fromEventIDs []string, limit int) (*gomatrixserverlib.Transaction, error) {
-
-	tx, err := b.fedClient.Backfill(ctx, server, roomID, limit, fromEventIDs)
-	return &tx, err
-}
-
-func (b *backfillRequester) ProvideEvents(roomVer gomatrixserverlib.RoomVersion, eventIDs []string) ([]gomatrixserverlib.Event, error) {
-	ctx := context.Background()
-	nidMap, err := b.db.EventNIDs(ctx, eventIDs)
-	if err != nil {
-		logrus.WithError(err).WithField("event_ids", eventIDs).Error("Failed to find events")
-		return nil, err
-	}
-	eventNIDs := make([]types.EventNID, len(nidMap))
-	i := 0
-	for _, nid := range nidMap {
-		eventNIDs[i] = nid
-		i++
-	}
-	eventsWithNids, err := b.db.Events(ctx, eventNIDs)
-	if err != nil {
-		logrus.WithError(err).WithField("event_nids", eventNIDs).Error("Failed to load events")
-		return nil, err
-	}
-	events := make([]gomatrixserverlib.Event, len(eventsWithNids))
-	for i := range eventsWithNids {
-		events[i] = eventsWithNids[i].Event
-	}
-	return events, nil
-}
-
-// joinEventsFromHistoryVisibility returns all CURRENTLY joined members if the provided state indicated a 'shared' history visibility.
-// TODO: Long term we probably want a history_visibility table which stores eventNID | visibility_enum so we can just
-//       pull all events and then filter by that table.
-func joinEventsFromHistoryVisibility(
-	ctx context.Context, db storage.Database, roomID string, stateEntries []types.StateEntry) ([]types.Event, error) {
-
-	var eventNIDs []types.EventNID
-	for _, entry := range stateEntries {
-		// Filter the events to retrieve to only keep the membership events
-		if entry.EventTypeNID == types.MRoomHistoryVisibilityNID && entry.EventStateKeyNID == types.EmptyStateKeyNID {
-			eventNIDs = append(eventNIDs, entry.EventNID)
-			break
-		}
-	}
-
-	// Get all of the events in this state
-	stateEvents, err := db.Events(ctx, eventNIDs)
-	if err != nil {
-		return nil, err
-	}
-	events := make([]gomatrixserverlib.Event, len(stateEvents))
-	for i := range stateEvents {
-		events[i] = stateEvents[i].Event
-	}
-	visibility := auth.HistoryVisibilityForRoom(events)
-	if visibility != "shared" {
-		logrus.Infof("ServersAtEvent history visibility not shared: %s", visibility)
-		return nil, nil
-	}
-	// get joined members
-	info, err := db.RoomInfo(ctx, roomID)
-	if err != nil {
-		return nil, err
-	}
-	joinEventNIDs, err := db.GetMembershipEventNIDsForRoom(ctx, info.RoomNID, true, false)
-	if err != nil {
-		return nil, err
-	}
-	return db.Events(ctx, joinEventNIDs)
-}

roomserver/internal/perform_leave.go

@@ -1,223 +0,0 @@
-package internal
-
-import (
-	"context"
-	"fmt"
-	"strings"
-	"time"
-
-	fsAPI "github.com/matrix-org/dendrite/federationsender/api"
-	"github.com/matrix-org/dendrite/internal/eventutil"
-	"github.com/matrix-org/dendrite/roomserver/api"
-	"github.com/matrix-org/dendrite/roomserver/types"
-	"github.com/matrix-org/gomatrixserverlib"
-)
-
-// WriteOutputEvents implements OutputRoomEventWriter
-func (r *RoomserverInternalAPI) PerformLeave(
-	ctx context.Context,
-	req *api.PerformLeaveRequest,
-	res *api.PerformLeaveResponse,
-) error {
-	_, domain, err := gomatrixserverlib.SplitID('@', req.UserID)
-	if err != nil {
-		return fmt.Errorf("Supplied user ID %q in incorrect format", req.UserID)
-	}
-	if domain != r.Cfg.Matrix.ServerName {
-		return fmt.Errorf("User %q does not belong to this homeserver", req.UserID)
-	}
-	if strings.HasPrefix(req.RoomID, "!") {
-		return r.performLeaveRoomByID(ctx, req, res)
-	}
-	return fmt.Errorf("Room ID %q is invalid", req.RoomID)
-}
-
-func (r *RoomserverInternalAPI) performLeaveRoomByID(
-	ctx context.Context,
-	req *api.PerformLeaveRequest,
-	res *api.PerformLeaveResponse, // nolint:unparam
-) error {
-	// If there's an invite outstanding for the room then respond to
-	// that.
-	isInvitePending, senderUser, eventID, err := r.isInvitePending(ctx, req.RoomID, req.UserID)
-	if err == nil && isInvitePending {
-		return r.performRejectInvite(ctx, req, res, senderUser, eventID)
-	}
-
-	// There's no invite pending, so first of all we want to find out
-	// if the room exists and if the user is actually in it.
-	latestReq := api.QueryLatestEventsAndStateRequest{
-		RoomID: req.RoomID,
-		StateToFetch: []gomatrixserverlib.StateKeyTuple{
-			{
-				EventType: gomatrixserverlib.MRoomMember,
-				StateKey:  req.UserID,
-			},
-		},
-	}
-	latestRes := api.QueryLatestEventsAndStateResponse{}
-	if err = r.QueryLatestEventsAndState(ctx, &latestReq, &latestRes); err != nil {
-		return err
-	}
-	if !latestRes.RoomExists {
-		return fmt.Errorf("Room %q does not exist", req.RoomID)
-	}
-
-	// Now let's see if the user is in the room.
-	if len(latestRes.StateEvents) == 0 {
-		return fmt.Errorf("User %q is not a member of room %q", req.UserID, req.RoomID)
-	}
-	membership, err := latestRes.StateEvents[0].Membership()
-	if err != nil {
-		return fmt.Errorf("Error getting membership: %w", err)
-	}
-	if membership != gomatrixserverlib.Join {
-		// TODO: should be able to handle "invite" in this case too, if
-		// it's a case of kicking or banning or such
-		return fmt.Errorf("User %q is not joined to the room (membership is %q)", req.UserID, membership)
-	}
-
-	// Prepare the template for the leave event.
-	userID := req.UserID
-	eb := gomatrixserverlib.EventBuilder{
-		Type:     gomatrixserverlib.MRoomMember,
-		Sender:   userID,
-		StateKey: &userID,
-		RoomID:   req.RoomID,
-		Redacts:  "",
-	}
-	if err = eb.SetContent(map[string]interface{}{"membership": "leave"}); err != nil {
-		return fmt.Errorf("eb.SetContent: %w", err)
-	}
-	if err = eb.SetUnsigned(struct{}{}); err != nil {
-		return fmt.Errorf("eb.SetUnsigned: %w", err)
-	}
-
-	// We know that the user is in the room at this point so let's build
-	// a leave event.
-	// TODO: Check what happens if the room exists on the server
-	// but everyone has since left. I suspect it does the wrong thing.
-	buildRes := api.QueryLatestEventsAndStateResponse{}
-	event, err := eventutil.BuildEvent(
-		ctx,          // the request context
-		&eb,          // the template leave event
-		r.Cfg.Matrix, // the server configuration
-		time.Now(),   // the event timestamp to use
-		r,            // the roomserver API to use
-		&buildRes,    // the query response
-	)
-	if err != nil {
-		return fmt.Errorf("eventutil.BuildEvent: %w", err)
-	}
-
-	// Give our leave event to the roomserver input stream. The
-	// roomserver will process the membership change and notify
-	// downstream automatically.
-	inputReq := api.InputRoomEventsRequest{
-		InputRoomEvents: []api.InputRoomEvent{
-			{
-				Kind:         api.KindNew,
-				Event:        event.Headered(buildRes.RoomVersion),
-				AuthEventIDs: event.AuthEventIDs(),
-				SendAsServer: string(r.Cfg.Matrix.ServerName),
-			},
-		},
-	}
-	inputRes := api.InputRoomEventsResponse{}
-	if err = r.InputRoomEvents(ctx, &inputReq, &inputRes); err != nil {
-		return fmt.Errorf("r.InputRoomEvents: %w", err)
-	}
-
-	return nil
-}
-
-func (r *RoomserverInternalAPI) performRejectInvite(
-	ctx context.Context,
-	req *api.PerformLeaveRequest,
-	res *api.PerformLeaveResponse, // nolint:unparam
-	senderUser, eventID string,
-) error {
-	_, domain, err := gomatrixserverlib.SplitID('@', senderUser)
-	if err != nil {
-		return fmt.Errorf("User ID %q invalid: %w", senderUser, err)
-	}
-
-	// Ask the federation sender to perform a federated leave for us.
-	leaveReq := fsAPI.PerformLeaveRequest{
-		RoomID:      req.RoomID,
-		UserID:      req.UserID,
-		ServerNames: []gomatrixserverlib.ServerName{domain},
-	}
-	leaveRes := fsAPI.PerformLeaveResponse{}
-	if err := r.fsAPI.PerformLeave(ctx, &leaveReq, &leaveRes); err != nil {
-		return err
-	}
-
-	// Withdraw the invite, so that the sync API etc are
-	// notified that we rejected it.
-	return r.WriteOutputEvents(req.RoomID, []api.OutputEvent{
-		{
-			Type: api.OutputTypeRetireInviteEvent,
-			RetireInviteEvent: &api.OutputRetireInviteEvent{
-				EventID:      eventID,
-				Membership:   "leave",
-				TargetUserID: req.UserID,
-			},
-		},
-	})
-}
-
-func (r *RoomserverInternalAPI) isInvitePending(
-	ctx context.Context,
-	roomID, userID string,
-) (bool, string, string, error) {
-	// Look up the room NID for the supplied room ID.
-	info, err := r.DB.RoomInfo(ctx, roomID)
-	if err != nil {
-		return false, "", "", fmt.Errorf("r.DB.RoomInfo: %w", err)
-	}
-	if info == nil {
-		return false, "", "", fmt.Errorf("cannot get RoomInfo: unknown room ID %s", roomID)
-	}
-
-	// Look up the state key NID for the supplied user ID.
-	targetUserNIDs, err := r.DB.EventStateKeyNIDs(ctx, []string{userID})
-	if err != nil {
-		return false, "", "", fmt.Errorf("r.DB.EventStateKeyNIDs: %w", err)
-	}
-	targetUserNID, targetUserFound := targetUserNIDs[userID]
-	if !targetUserFound {
-		return false, "", "", fmt.Errorf("missing NID for user %q (%+v)", userID, targetUserNIDs)
-	}
-
-	// Let's see if we have an event active for the user in the room. If
-	// we do then it will contain a server name that we can direct the
-	// send_leave to.
-	senderUserNIDs, eventIDs, err := r.DB.GetInvitesForUser(ctx, info.RoomNID, targetUserNID)
-	if err != nil {
-		return false, "", "", fmt.Errorf("r.DB.GetInvitesForUser: %w", err)
-	}
-	if len(senderUserNIDs) == 0 {
-		return false, "", "", nil
-	}
-	userNIDToEventID := make(map[types.EventStateKeyNID]string)
-	for i, nid := range senderUserNIDs {
-		userNIDToEventID[nid] = eventIDs[i]
-	}
-
-	// Look up the user ID from the NID.
-	senderUsers, err := r.DB.EventStateKeys(ctx, senderUserNIDs)
-	if err != nil {
-		return false, "", "", fmt.Errorf("r.DB.EventStateKeys: %w", err)
-	}
-	if len(senderUsers) == 0 {
-		return false, "", "", fmt.Errorf("no senderUsers")
-	}
-
-	senderUser, senderUserFound := senderUsers[senderUserNIDs[0]]
-	if !senderUserFound {
-		return false, "", "", fmt.Errorf("missing user for NID %d (%+v)", senderUserNIDs[0], senderUsers)
-	}
-
-	return true, senderUser, userNIDToEventID[senderUserNIDs[0]], nil
-}

roomserver/internal/perform_publish.go

@@ -1,20 +0,0 @@
-package internal
-
-import (
-	"context"
-
-	"github.com/matrix-org/dendrite/roomserver/api"
-)
-
-func (r *RoomserverInternalAPI) PerformPublish(
-	ctx context.Context,
-	req *api.PerformPublishRequest,
-	res *api.PerformPublishResponse,
-) {
-	err := r.DB.PublishRoom(ctx, req.RoomID, req.Visibility == "public")
-	if err != nil {
-		res.Error = &api.PerformError{
-			Msg: err.Error(),
-		}
-	}
-}

roomserver/internal/query.go

@@ -1,960 +0,0 @@
-// Copyright 2017 Vector Creations Ltd
-// Copyright 2018 New Vector Ltd
-// Copyright 2019-2020 The Matrix.org Foundation C.I.C.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package internal
-
-import (
-	"context"
-	"fmt"
-
-	"github.com/matrix-org/dendrite/internal/eventutil"
-	"github.com/matrix-org/dendrite/roomserver/api"
-	"github.com/matrix-org/dendrite/roomserver/auth"
-	"github.com/matrix-org/dendrite/roomserver/state"
-	"github.com/matrix-org/dendrite/roomserver/storage"
-	"github.com/matrix-org/dendrite/roomserver/types"
-	"github.com/matrix-org/dendrite/roomserver/version"
-	"github.com/matrix-org/gomatrixserverlib"
-	"github.com/matrix-org/util"
-	"github.com/sirupsen/logrus"
-)
-
-// QueryLatestEventsAndState implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryLatestEventsAndState(
-	ctx context.Context,
-	request *api.QueryLatestEventsAndStateRequest,
-	response *api.QueryLatestEventsAndStateResponse,
-) error {
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, request.RoomID)
-	if err != nil {
-		response.RoomExists = false
-		return nil
-	}
-
-	roomState := state.NewStateResolution(r.DB)
-
-	info, err := r.DB.RoomInfo(ctx, request.RoomID)
-	if err != nil {
-		return err
-	}
-	if info.IsStub {
-		return nil
-	}
-	response.RoomExists = true
-	response.RoomVersion = roomVersion
-
-	var currentStateSnapshotNID types.StateSnapshotNID
-	response.LatestEvents, currentStateSnapshotNID, response.Depth, err =
-		r.DB.LatestEventIDs(ctx, info.RoomNID)
-	if err != nil {
-		return err
-	}
-
-	var stateEntries []types.StateEntry
-	if len(request.StateToFetch) == 0 {
-		// Look up all room state.
-		stateEntries, err = roomState.LoadStateAtSnapshot(
-			ctx, currentStateSnapshotNID,
-		)
-	} else {
-		// Look up the current state for the requested tuples.
-		stateEntries, err = roomState.LoadStateAtSnapshotForStringTuples(
-			ctx, currentStateSnapshotNID, request.StateToFetch,
-		)
-	}
-	if err != nil {
-		return err
-	}
-
-	stateEvents, err := r.loadStateEvents(ctx, stateEntries)
-	if err != nil {
-		return err
-	}
-
-	for _, event := range stateEvents {
-		response.StateEvents = append(response.StateEvents, event.Headered(roomVersion))
-	}
-
-	return nil
-}
-
-// QueryStateAfterEvents implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryStateAfterEvents(
-	ctx context.Context,
-	request *api.QueryStateAfterEventsRequest,
-	response *api.QueryStateAfterEventsResponse,
-) error {
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, request.RoomID)
-	if err != nil {
-		response.RoomExists = false
-		return nil
-	}
-
-	roomState := state.NewStateResolution(r.DB)
-
-	info, err := r.DB.RoomInfo(ctx, request.RoomID)
-	if err != nil {
-		return err
-	}
-	if info.IsStub {
-		return nil
-	}
-	response.RoomExists = true
-	response.RoomVersion = roomVersion
-
-	prevStates, err := r.DB.StateAtEventIDs(ctx, request.PrevEventIDs)
-	if err != nil {
-		switch err.(type) {
-		case types.MissingEventError:
-			return nil
-		default:
-			return err
-		}
-	}
-	response.PrevEventsExist = true
-
-	// Look up the currrent state for the requested tuples.
-	stateEntries, err := roomState.LoadStateAfterEventsForStringTuples(
-		ctx, info.RoomNID, prevStates, request.StateToFetch,
-	)
-	if err != nil {
-		return err
-	}
-
-	stateEvents, err := r.loadStateEvents(ctx, stateEntries)
-	if err != nil {
-		return err
-	}
-
-	for _, event := range stateEvents {
-		response.StateEvents = append(response.StateEvents, event.Headered(roomVersion))
-	}
-
-	return nil
-}
-
-// QueryEventsByID implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryEventsByID(
-	ctx context.Context,
-	request *api.QueryEventsByIDRequest,
-	response *api.QueryEventsByIDResponse,
-) error {
-	eventNIDMap, err := r.DB.EventNIDs(ctx, request.EventIDs)
-	if err != nil {
-		return err
-	}
-
-	var eventNIDs []types.EventNID
-	for _, nid := range eventNIDMap {
-		eventNIDs = append(eventNIDs, nid)
-	}
-
-	events, err := r.loadEvents(ctx, eventNIDs)
-	if err != nil {
-		return err
-	}
-
-	for _, event := range events {
-		roomVersion, verr := r.DB.GetRoomVersionForRoom(ctx, event.RoomID())
-		if verr != nil {
-			return verr
-		}
-
-		response.Events = append(response.Events, event.Headered(roomVersion))
-	}
-
-	return nil
-}
-
-func (r *RoomserverInternalAPI) loadStateEvents(
-	ctx context.Context, stateEntries []types.StateEntry,
-) ([]gomatrixserverlib.Event, error) {
-	eventNIDs := make([]types.EventNID, len(stateEntries))
-	for i := range stateEntries {
-		eventNIDs[i] = stateEntries[i].EventNID
-	}
-	return r.loadEvents(ctx, eventNIDs)
-}
-
-func (r *RoomserverInternalAPI) loadEvents(
-	ctx context.Context, eventNIDs []types.EventNID,
-) ([]gomatrixserverlib.Event, error) {
-	stateEvents, err := r.DB.Events(ctx, eventNIDs)
-	if err != nil {
-		return nil, err
-	}
-
-	result := make([]gomatrixserverlib.Event, len(stateEvents))
-	for i := range stateEvents {
-		result[i] = stateEvents[i].Event
-	}
-	return result, nil
-}
-
-// QueryMembershipForUser implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryMembershipForUser(
-	ctx context.Context,
-	request *api.QueryMembershipForUserRequest,
-	response *api.QueryMembershipForUserResponse,
-) error {
-	info, err := r.DB.RoomInfo(ctx, request.RoomID)
-	if err != nil {
-		return err
-	}
-
-	membershipEventNID, stillInRoom, err := r.DB.GetMembership(ctx, info.RoomNID, request.UserID)
-	if err != nil {
-		return err
-	}
-
-	if membershipEventNID == 0 {
-		response.HasBeenInRoom = false
-		return nil
-	}
-
-	response.IsInRoom = stillInRoom
-	response.HasBeenInRoom = true
-
-	evs, err := r.DB.Events(ctx, []types.EventNID{membershipEventNID})
-	if err != nil {
-		return err
-	}
-	if len(evs) != 1 {
-		return fmt.Errorf("failed to load membership event for event NID %d", membershipEventNID)
-	}
-
-	response.EventID = evs[0].EventID()
-	response.Membership, err = evs[0].Membership()
-	return err
-}
-
-// QueryMembershipsForRoom implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryMembershipsForRoom(
-	ctx context.Context,
-	request *api.QueryMembershipsForRoomRequest,
-	response *api.QueryMembershipsForRoomResponse,
-) error {
-	info, err := r.DB.RoomInfo(ctx, request.RoomID)
-	if err != nil {
-		return err
-	}
-
-	membershipEventNID, stillInRoom, err := r.DB.GetMembership(ctx, info.RoomNID, request.Sender)
-	if err != nil {
-		return err
-	}
-
-	if membershipEventNID == 0 {
-		response.HasBeenInRoom = false
-		response.JoinEvents = nil
-		return nil
-	}
-
-	response.HasBeenInRoom = true
-	response.JoinEvents = []gomatrixserverlib.ClientEvent{}
-
-	var events []types.Event
-	var stateEntries []types.StateEntry
-	if stillInRoom {
-		var eventNIDs []types.EventNID
-		eventNIDs, err = r.DB.GetMembershipEventNIDsForRoom(ctx, info.RoomNID, request.JoinedOnly, false)
-		if err != nil {
-			return err
-		}
-
-		events, err = r.DB.Events(ctx, eventNIDs)
-	} else {
-		stateEntries, err = stateBeforeEvent(ctx, r.DB, membershipEventNID)
-		if err != nil {
-			logrus.WithField("membership_event_nid", membershipEventNID).WithError(err).Error("failed to load state before event")
-			return err
-		}
-		events, err = getMembershipsAtState(ctx, r.DB, stateEntries, request.JoinedOnly)
-	}
-
-	if err != nil {
-		return err
-	}
-
-	for _, event := range events {
-		clientEvent := gomatrixserverlib.ToClientEvent(event.Event, gomatrixserverlib.FormatAll)
-		response.JoinEvents = append(response.JoinEvents, clientEvent)
-	}
-
-	return nil
-}
-
-func stateBeforeEvent(ctx context.Context, db storage.Database, eventNID types.EventNID) ([]types.StateEntry, error) {
-	roomState := state.NewStateResolution(db)
-	// Lookup the event NID
-	eIDs, err := db.EventIDs(ctx, []types.EventNID{eventNID})
-	if err != nil {
-		return nil, err
-	}
-	eventIDs := []string{eIDs[eventNID]}
-
-	prevState, err := db.StateAtEventIDs(ctx, eventIDs)
-	if err != nil {
-		return nil, err
-	}
-
-	// Fetch the state as it was when this event was fired
-	return roomState.LoadCombinedStateAfterEvents(ctx, prevState)
-}
-
-// getMembershipsAtState filters the state events to
-// only keep the "m.room.member" events with a "join" membership. These events are returned.
-// Returns an error if there was an issue fetching the events.
-func getMembershipsAtState(
-	ctx context.Context, db storage.Database, stateEntries []types.StateEntry, joinedOnly bool,
-) ([]types.Event, error) {
-
-	var eventNIDs []types.EventNID
-	for _, entry := range stateEntries {
-		// Filter the events to retrieve to only keep the membership events
-		if entry.EventTypeNID == types.MRoomMemberNID {
-			eventNIDs = append(eventNIDs, entry.EventNID)
-		}
-	}
-
-	// Get all of the events in this state
-	stateEvents, err := db.Events(ctx, eventNIDs)
-	if err != nil {
-		return nil, err
-	}
-
-	if !joinedOnly {
-		return stateEvents, nil
-	}
-
-	// Filter the events to only keep the "join" membership events
-	var events []types.Event
-	for _, event := range stateEvents {
-		membership, err := event.Membership()
-		if err != nil {
-			return nil, err
-		}
-
-		if membership == gomatrixserverlib.Join {
-			events = append(events, event)
-		}
-	}
-
-	return events, nil
-}
-
-// QueryServerAllowedToSeeEvent implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryServerAllowedToSeeEvent(
-	ctx context.Context,
-	request *api.QueryServerAllowedToSeeEventRequest,
-	response *api.QueryServerAllowedToSeeEventResponse,
-) (err error) {
-	events, err := r.DB.EventsFromIDs(ctx, []string{request.EventID})
-	if err != nil {
-		return
-	}
-	if len(events) == 0 {
-		response.AllowedToSeeEvent = false // event doesn't exist so not allowed to see
-		return
-	}
-	isServerInRoom, err := r.isServerCurrentlyInRoom(ctx, request.ServerName, events[0].RoomID())
-	if err != nil {
-		return
-	}
-	response.AllowedToSeeEvent, err = r.checkServerAllowedToSeeEvent(
-		ctx, request.EventID, request.ServerName, isServerInRoom,
-	)
-	return
-}
-
-func (r *RoomserverInternalAPI) checkServerAllowedToSeeEvent(
-	ctx context.Context, eventID string, serverName gomatrixserverlib.ServerName, isServerInRoom bool,
-) (bool, error) {
-	roomState := state.NewStateResolution(r.DB)
-	stateEntries, err := roomState.LoadStateAtEvent(ctx, eventID)
-	if err != nil {
-		return false, err
-	}
-
-	// TODO: We probably want to make it so that we don't have to pull
-	// out all the state if possible.
-	stateAtEvent, err := r.loadStateEvents(ctx, stateEntries)
-	if err != nil {
-		return false, err
-	}
-
-	return auth.IsServerAllowed(serverName, isServerInRoom, stateAtEvent), nil
-}
-
-// QueryMissingEvents implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryMissingEvents(
-	ctx context.Context,
-	request *api.QueryMissingEventsRequest,
-	response *api.QueryMissingEventsResponse,
-) error {
-	var front []string
-	eventsToFilter := make(map[string]bool, len(request.LatestEvents))
-	visited := make(map[string]bool, request.Limit) // request.Limit acts as a hint to size.
-	for _, id := range request.EarliestEvents {
-		visited[id] = true
-	}
-
-	for _, id := range request.LatestEvents {
-		if !visited[id] {
-			front = append(front, id)
-			eventsToFilter[id] = true
-		}
-	}
-
-	resultNIDs, err := r.scanEventTree(ctx, front, visited, request.Limit, request.ServerName)
-	if err != nil {
-		return err
-	}
-
-	loadedEvents, err := r.loadEvents(ctx, resultNIDs)
-	if err != nil {
-		return err
-	}
-
-	response.Events = make([]gomatrixserverlib.HeaderedEvent, 0, len(loadedEvents)-len(eventsToFilter))
-	for _, event := range loadedEvents {
-		if !eventsToFilter[event.EventID()] {
-			roomVersion, verr := r.DB.GetRoomVersionForRoom(ctx, event.RoomID())
-			if verr != nil {
-				return verr
-			}
-
-			response.Events = append(response.Events, event.Headered(roomVersion))
-		}
-	}
-
-	return err
-}
-
-// PerformBackfill implements api.RoomServerQueryAPI
-func (r *RoomserverInternalAPI) PerformBackfill(
-	ctx context.Context,
-	request *api.PerformBackfillRequest,
-	response *api.PerformBackfillResponse,
-) error {
-	// if we are requesting the backfill then we need to do a federation hit
-	// TODO: we could be more sensible and fetch as many events we already have then request the rest
-	//       which is what the syncapi does already.
-	if request.ServerName == r.ServerName {
-		return r.backfillViaFederation(ctx, request, response)
-	}
-	// someone else is requesting the backfill, try to service their request.
-	var err error
-	var front []string
-
-	// The limit defines the maximum number of events to retrieve, so it also
-	// defines the highest number of elements in the map below.
-	visited := make(map[string]bool, request.Limit)
-
-	// this will include these events which is what we want
-	front = request.PrevEventIDs()
-
-	// Scan the event tree for events to send back.
-	resultNIDs, err := r.scanEventTree(ctx, front, visited, request.Limit, request.ServerName)
-	if err != nil {
-		return err
-	}
-
-	// Retrieve events from the list that was filled previously.
-	var loadedEvents []gomatrixserverlib.Event
-	loadedEvents, err = r.loadEvents(ctx, resultNIDs)
-	if err != nil {
-		return err
-	}
-
-	for _, event := range loadedEvents {
-		roomVersion, verr := r.DB.GetRoomVersionForRoom(ctx, event.RoomID())
-		if verr != nil {
-			return verr
-		}
-
-		response.Events = append(response.Events, event.Headered(roomVersion))
-	}
-
-	return err
-}
-
-func (r *RoomserverInternalAPI) backfillViaFederation(ctx context.Context, req *api.PerformBackfillRequest, res *api.PerformBackfillResponse) error {
-	roomVer, err := r.DB.GetRoomVersionForRoom(ctx, req.RoomID)
-	if err != nil {
-		return fmt.Errorf("backfillViaFederation: unknown room version for room %s : %w", req.RoomID, err)
-	}
-	requester := newBackfillRequester(r.DB, r.FedClient, r.ServerName, req.BackwardsExtremities)
-	// Request 100 items regardless of what the query asks for.
-	// We don't want to go much higher than this.
-	// We can't honour exactly the limit as some sytests rely on requesting more for tests to pass
-	// (so we don't need to hit /state_ids which the test has no listener for)
-	// Specifically the test "Outbound federation can backfill events"
-	events, err := gomatrixserverlib.RequestBackfill(
-		ctx, requester,
-		r.KeyRing, req.RoomID, roomVer, req.PrevEventIDs(), 100)
-	if err != nil {
-		return err
-	}
-	logrus.WithField("room_id", req.RoomID).Infof("backfilled %d events", len(events))
-
-	// persist these new events - auth checks have already been done
-	roomNID, backfilledEventMap := persistEvents(ctx, r.DB, events)
-	if err != nil {
-		return err
-	}
-
-	for _, ev := range backfilledEventMap {
-		// now add state for these events
-		stateIDs, ok := requester.eventIDToBeforeStateIDs[ev.EventID()]
-		if !ok {
-			// this should be impossible as all events returned must have pass Step 5 of the PDU checks
-			// which requires a list of state IDs.
-			logrus.WithError(err).WithField("event_id", ev.EventID()).Error("backfillViaFederation: failed to find state IDs for event which passed auth checks")
-			continue
-		}
-		var entries []types.StateEntry
-		if entries, err = r.DB.StateEntriesForEventIDs(ctx, stateIDs); err != nil {
-			// attempt to fetch the missing events
-			r.fetchAndStoreMissingEvents(ctx, roomVer, requester, stateIDs)
-			// try again
-			entries, err = r.DB.StateEntriesForEventIDs(ctx, stateIDs)
-			if err != nil {
-				logrus.WithError(err).WithField("event_id", ev.EventID()).Error("backfillViaFederation: failed to get state entries for event")
-				return err
-			}
-		}
-
-		var beforeStateSnapshotNID types.StateSnapshotNID
-		if beforeStateSnapshotNID, err = r.DB.AddState(ctx, roomNID, nil, entries); err != nil {
-			logrus.WithError(err).WithField("event_id", ev.EventID()).Error("backfillViaFederation: failed to persist state entries to get snapshot nid")
-			return err
-		}
-		if err = r.DB.SetState(ctx, ev.EventNID, beforeStateSnapshotNID); err != nil {
-			logrus.WithError(err).WithField("event_id", ev.EventID()).Error("backfillViaFederation: failed to persist snapshot nid")
-		}
-	}
-
-	// TODO: update backwards extremities, as that should be moved from syncapi to roomserver at some point.
-
-	res.Events = events
-	return nil
-}
-
-func (r *RoomserverInternalAPI) isServerCurrentlyInRoom(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID string) (bool, error) {
-	info, err := r.DB.RoomInfo(ctx, roomID)
-	if err != nil {
-		return false, err
-	}
-	if info == nil {
-		return false, fmt.Errorf("unknown room %s", roomID)
-	}
-
-	eventNIDs, err := r.DB.GetMembershipEventNIDsForRoom(ctx, info.RoomNID, true, false)
-	if err != nil {
-		return false, err
-	}
-
-	events, err := r.DB.Events(ctx, eventNIDs)
-	if err != nil {
-		return false, err
-	}
-	gmslEvents := make([]gomatrixserverlib.Event, len(events))
-	for i := range events {
-		gmslEvents[i] = events[i].Event
-	}
-	return auth.IsAnyUserOnServerWithMembership(serverName, gmslEvents, gomatrixserverlib.Join), nil
-}
-
-// fetchAndStoreMissingEvents does a best-effort fetch and store of missing events specified in stateIDs. Returns no error as it is just
-// best effort.
-func (r *RoomserverInternalAPI) fetchAndStoreMissingEvents(ctx context.Context, roomVer gomatrixserverlib.RoomVersion,
-	backfillRequester *backfillRequester, stateIDs []string) {
-
-	servers := backfillRequester.servers
-
-	// work out which are missing
-	nidMap, err := r.DB.EventNIDs(ctx, stateIDs)
-	if err != nil {
-		util.GetLogger(ctx).WithError(err).Warn("cannot query missing events")
-		return
-	}
-	missingMap := make(map[string]*gomatrixserverlib.HeaderedEvent) // id -> event
-	for _, id := range stateIDs {
-		if _, ok := nidMap[id]; !ok {
-			missingMap[id] = nil
-		}
-	}
-	util.GetLogger(ctx).Infof("Fetching %d missing state events (from %d possible servers)", len(missingMap), len(servers))
-
-	// fetch the events from federation. Loop the servers first so if we find one that works we stick with them
-	for _, srv := range servers {
-		for id, ev := range missingMap {
-			if ev != nil {
-				continue // already found
-			}
-			logger := util.GetLogger(ctx).WithField("server", srv).WithField("event_id", id)
-			res, err := r.FedClient.GetEvent(ctx, srv, id)
-			if err != nil {
-				logger.WithError(err).Warn("failed to get event from server")
-				continue
-			}
-			loader := gomatrixserverlib.NewEventsLoader(roomVer, r.KeyRing, backfillRequester, backfillRequester.ProvideEvents, false)
-			result, err := loader.LoadAndVerify(ctx, res.PDUs, gomatrixserverlib.TopologicalOrderByPrevEvents)
-			if err != nil {
-				logger.WithError(err).Warn("failed to load and verify event")
-				continue
-			}
-			logger.Infof("returned %d PDUs which made events %+v", len(res.PDUs), result)
-			for _, res := range result {
-				if res.Error != nil {
-					logger.WithError(err).Warn("event failed PDU checks")
-					continue
-				}
-				missingMap[id] = res.Event
-			}
-		}
-	}
-
-	var newEvents []gomatrixserverlib.HeaderedEvent
-	for _, ev := range missingMap {
-		if ev != nil {
-			newEvents = append(newEvents, *ev)
-		}
-	}
-	util.GetLogger(ctx).Infof("Persisting %d new events", len(newEvents))
-	persistEvents(ctx, r.DB, newEvents)
-}
-
-// TODO: Remove this when we have tests to assert correctness of this function
-// nolint:gocyclo
-func (r *RoomserverInternalAPI) scanEventTree(
-	ctx context.Context, front []string, visited map[string]bool, limit int,
-	serverName gomatrixserverlib.ServerName,
-) ([]types.EventNID, error) {
-	var resultNIDs []types.EventNID
-	var err error
-	var allowed bool
-	var events []types.Event
-	var next []string
-	var pre string
-
-	// TODO: add tests for this function to ensure it meets the contract that callers expect (and doc what that is supposed to be)
-	// Currently, callers like PerformBackfill will call scanEventTree with a pre-populated `visited` map, assuming that by doing
-	// so means that the events in that map will NOT be returned from this function. That is not currently true, resulting in
-	// duplicate events being sent in response to /backfill requests.
-	initialIgnoreList := make(map[string]bool, len(visited))
-	for k, v := range visited {
-		initialIgnoreList[k] = v
-	}
-
-	resultNIDs = make([]types.EventNID, 0, limit)
-
-	var checkedServerInRoom bool
-	var isServerInRoom bool
-
-	// Loop through the event IDs to retrieve the requested events and go
-	// through the whole tree (up to the provided limit) using the events'
-	// "prev_event" key.
-BFSLoop:
-	for len(front) > 0 {
-		// Prevent unnecessary allocations: reset the slice only when not empty.
-		if len(next) > 0 {
-			next = make([]string, 0)
-		}
-		// Retrieve the events to process from the database.
-		events, err = r.DB.EventsFromIDs(ctx, front)
-		if err != nil {
-			return resultNIDs, err
-		}
-
-		if !checkedServerInRoom && len(events) > 0 {
-			// It's nasty that we have to extract the room ID from an event, but many federation requests
-			// only talk in event IDs, no room IDs at all (!!!)
-			ev := events[0]
-			isServerInRoom, err = r.isServerCurrentlyInRoom(ctx, serverName, ev.RoomID())
-			if err != nil {
-				util.GetLogger(ctx).WithError(err).Error("Failed to check if server is currently in room, assuming not.")
-			}
-			checkedServerInRoom = true
-		}
-
-		for _, ev := range events {
-			// Break out of the loop if the provided limit is reached.
-			if len(resultNIDs) == limit {
-				break BFSLoop
-			}
-
-			if !initialIgnoreList[ev.EventID()] {
-				// Update the list of events to retrieve.
-				resultNIDs = append(resultNIDs, ev.EventNID)
-			}
-			// Loop through the event's parents.
-			for _, pre = range ev.PrevEventIDs() {
-				// Only add an event to the list of next events to process if it
-				// hasn't been seen before.
-				if !visited[pre] {
-					visited[pre] = true
-					allowed, err = r.checkServerAllowedToSeeEvent(ctx, pre, serverName, isServerInRoom)
-					if err != nil {
-						util.GetLogger(ctx).WithField("server", serverName).WithField("event_id", pre).WithError(err).Error(
-							"Error checking if allowed to see event",
-						)
-						return resultNIDs, err
-					}
-
-					// If the event hasn't been seen before and the HS
-					// requesting to retrieve it is allowed to do so, add it to
-					// the list of events to retrieve.
-					if allowed {
-						next = append(next, pre)
-					} else {
-						util.GetLogger(ctx).WithField("server", serverName).WithField("event_id", pre).Info("Not allowed to see event")
-					}
-				}
-			}
-		}
-		// Repeat the same process with the parent events we just processed.
-		front = next
-	}
-
-	return resultNIDs, err
-}
-
-// QueryStateAndAuthChain implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryStateAndAuthChain(
-	ctx context.Context,
-	request *api.QueryStateAndAuthChainRequest,
-	response *api.QueryStateAndAuthChainResponse,
-) error {
-	info, err := r.DB.RoomInfo(ctx, request.RoomID)
-	if err != nil {
-		return err
-	}
-	if info.IsStub {
-		return nil
-	}
-	response.RoomExists = true
-	response.RoomVersion = info.RoomVersion
-
-	stateEvents, err := r.loadStateAtEventIDs(ctx, request.PrevEventIDs)
-	if err != nil {
-		return err
-	}
-	response.PrevEventsExist = true
-
-	// add the auth event IDs for the current state events too
-	var authEventIDs []string
-	authEventIDs = append(authEventIDs, request.AuthEventIDs...)
-	for _, se := range stateEvents {
-		authEventIDs = append(authEventIDs, se.AuthEventIDs()...)
-	}
-	authEventIDs = util.UniqueStrings(authEventIDs) // de-dupe
-
-	authEvents, err := getAuthChain(ctx, r.DB.EventsFromIDs, authEventIDs)
-	if err != nil {
-		return err
-	}
-
-	if request.ResolveState {
-		if stateEvents, err = state.ResolveConflictsAdhoc(
-			info.RoomVersion, stateEvents, authEvents,
-		); err != nil {
-			return err
-		}
-	}
-
-	for _, event := range stateEvents {
-		response.StateEvents = append(response.StateEvents, event.Headered(info.RoomVersion))
-	}
-
-	for _, event := range authEvents {
-		response.AuthChainEvents = append(response.AuthChainEvents, event.Headered(info.RoomVersion))
-	}
-
-	return err
-}
-
-func (r *RoomserverInternalAPI) loadStateAtEventIDs(ctx context.Context, eventIDs []string) ([]gomatrixserverlib.Event, error) {
-	roomState := state.NewStateResolution(r.DB)
-	prevStates, err := r.DB.StateAtEventIDs(ctx, eventIDs)
-	if err != nil {
-		switch err.(type) {
-		case types.MissingEventError:
-			return nil, nil
-		default:
-			return nil, err
-		}
-	}
-
-	// Look up the currrent state for the requested tuples.
-	stateEntries, err := roomState.LoadCombinedStateAfterEvents(
-		ctx, prevStates,
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	return r.loadStateEvents(ctx, stateEntries)
-}
-
-type eventsFromIDs func(context.Context, []string) ([]types.Event, error)
-
-// getAuthChain fetches the auth chain for the given auth events. An auth chain
-// is the list of all events that are referenced in the auth_events section, and
-// all their auth_events, recursively. The returned set of events contain the
-// given events. Will *not* error if we don't have all auth events.
-func getAuthChain(
-	ctx context.Context, fn eventsFromIDs, authEventIDs []string,
-) ([]gomatrixserverlib.Event, error) {
-	// List of event IDs to fetch. On each pass, these events will be requested
-	// from the database and the `eventsToFetch` will be updated with any new
-	// events that we have learned about and need to find. When `eventsToFetch`
-	// is eventually empty, we should have reached the end of the chain.
-	eventsToFetch := authEventIDs
-	authEventsMap := make(map[string]gomatrixserverlib.Event)
-
-	for len(eventsToFetch) > 0 {
-		// Try to retrieve the events from the database.
-		events, err := fn(ctx, eventsToFetch)
-		if err != nil {
-			return nil, err
-		}
-
-		// We've now fetched these events so clear out `eventsToFetch`. Soon we may
-		// add newly discovered events to this for the next pass.
-		eventsToFetch = eventsToFetch[:0]
-
-		for _, event := range events {
-			// Store the event in the event map - this prevents us from requesting it
-			// from the database again.
-			authEventsMap[event.EventID()] = event.Event
-
-			// Extract all of the auth events from the newly obtained event. If we
-			// don't already have a record of the event, record it in the list of
-			// events we want to request for the next pass.
-			for _, authEvent := range event.AuthEvents() {
-				if _, ok := authEventsMap[authEvent.EventID]; !ok {
-					eventsToFetch = append(eventsToFetch, authEvent.EventID)
-				}
-			}
-		}
-	}
-
-	// We've now retrieved all of the events we can. Flatten them down into an
-	// array and return them.
-	var authEvents []gomatrixserverlib.Event
-	for _, event := range authEventsMap {
-		authEvents = append(authEvents, event)
-	}
-
-	return authEvents, nil
-}
-
-func persistEvents(ctx context.Context, db storage.Database, events []gomatrixserverlib.HeaderedEvent) (types.RoomNID, map[string]types.Event) {
-	var roomNID types.RoomNID
-	backfilledEventMap := make(map[string]types.Event)
-	for j, ev := range events {
-		nidMap, err := db.EventNIDs(ctx, ev.AuthEventIDs())
-		if err != nil { // this shouldn't happen as RequestBackfill already found them
-			logrus.WithError(err).WithField("auth_events", ev.AuthEventIDs()).Error("Failed to find one or more auth events")
-			continue
-		}
-		authNids := make([]types.EventNID, len(nidMap))
-		i := 0
-		for _, nid := range nidMap {
-			authNids[i] = nid
-			i++
-		}
-		var stateAtEvent types.StateAtEvent
-		var redactedEventID string
-		var redactionEvent *gomatrixserverlib.Event
-		roomNID, stateAtEvent, redactionEvent, redactedEventID, err = db.StoreEvent(ctx, ev.Unwrap(), nil, authNids)
-		if err != nil {
-			logrus.WithError(err).WithField("event_id", ev.EventID()).Error("Failed to persist event")
-			continue
-		}
-		// If storing this event results in it being redacted, then do so.
-		// It's also possible for this event to be a redaction which results in another event being
-		// redacted, which we don't care about since we aren't returning it in this backfill.
-		if redactedEventID == ev.EventID() {
-			eventToRedact := ev.Unwrap()
-			redactedEvent, err := eventutil.RedactEvent(redactionEvent, &eventToRedact)
-			if err != nil {
-				logrus.WithError(err).WithField("event_id", ev.EventID()).Error("Failed to redact event")
-				continue
-			}
-			ev = redactedEvent.Headered(ev.RoomVersion)
-			events[j] = ev
-		}
-		backfilledEventMap[ev.EventID()] = types.Event{
-			EventNID: stateAtEvent.StateEntry.EventNID,
-			Event:    ev.Unwrap(),
-		}
-	}
-	return roomNID, backfilledEventMap
-}
-
-// QueryRoomVersionCapabilities implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryRoomVersionCapabilities(
-	ctx context.Context,
-	request *api.QueryRoomVersionCapabilitiesRequest,
-	response *api.QueryRoomVersionCapabilitiesResponse,
-) error {
-	response.DefaultRoomVersion = version.DefaultRoomVersion()
-	response.AvailableRoomVersions = make(map[gomatrixserverlib.RoomVersion]string)
-	for v, desc := range version.SupportedRoomVersions() {
-		if desc.Stable {
-			response.AvailableRoomVersions[v] = "stable"
-		} else {
-			response.AvailableRoomVersions[v] = "unstable"
-		}
-	}
-	return nil
-}
-
-// QueryRoomVersionCapabilities implements api.RoomserverInternalAPI
-func (r *RoomserverInternalAPI) QueryRoomVersionForRoom(
-	ctx context.Context,
-	request *api.QueryRoomVersionForRoomRequest,
-	response *api.QueryRoomVersionForRoomResponse,
-) error {
-	if roomVersion, ok := r.Cache.GetRoomVersion(request.RoomID); ok {
-		response.RoomVersion = roomVersion
-		return nil
-	}
-
-	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, request.RoomID)
-	if err != nil {
-		return err
-	}
-	response.RoomVersion = roomVersion
-	r.Cache.StoreRoomVersion(request.RoomID, response.RoomVersion)
-	return nil
-}
-
-func (r *RoomserverInternalAPI) QueryPublishedRooms(
-	ctx context.Context,
-	req *api.QueryPublishedRoomsRequest,
-	res *api.QueryPublishedRoomsResponse,
-) error {
-	rooms, err := r.DB.GetPublishedRooms(ctx)
-	if err != nil {
-		return err
-	}
-	res.RoomIDs = rooms
-	return nil
-}

roomserver/internal/query/query.go

@@ -0,0 +1,602 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package query
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
+	"github.com/matrix-org/dendrite/internal/caching"
+	"github.com/matrix-org/dendrite/roomserver/acls"
+	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/roomserver/internal/helpers"
+	"github.com/matrix-org/dendrite/roomserver/state"
+	"github.com/matrix-org/dendrite/roomserver/storage"
+	"github.com/matrix-org/dendrite/roomserver/types"
+	"github.com/matrix-org/dendrite/roomserver/version"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+	"github.com/sirupsen/logrus"
+)
+
+type Queryer struct {
+	DB         storage.Database
+	Cache      caching.RoomServerCaches
+	ServerACLs *acls.ServerACLs
+}
+
+// QueryLatestEventsAndState implements api.RoomserverInternalAPI
+func (r *Queryer) QueryLatestEventsAndState(
+	ctx context.Context,
+	request *api.QueryLatestEventsAndStateRequest,
+	response *api.QueryLatestEventsAndStateResponse,
+) error {
+	return helpers.QueryLatestEventsAndState(ctx, r.DB, request, response)
+}
+
+// QueryStateAfterEvents implements api.RoomserverInternalAPI
+func (r *Queryer) QueryStateAfterEvents(
+	ctx context.Context,
+	request *api.QueryStateAfterEventsRequest,
+	response *api.QueryStateAfterEventsResponse,
+) error {
+	info, err := r.DB.RoomInfo(ctx, request.RoomID)
+	if err != nil {
+		return err
+	}
+	if info == nil || info.IsStub {
+		return nil
+	}
+
+	roomState := state.NewStateResolution(r.DB, *info)
+	response.RoomExists = true
+	response.RoomVersion = info.RoomVersion
+
+	prevStates, err := r.DB.StateAtEventIDs(ctx, request.PrevEventIDs)
+	if err != nil {
+		switch err.(type) {
+		case types.MissingEventError:
+			return nil
+		default:
+			return err
+		}
+	}
+	response.PrevEventsExist = true
+
+	// Look up the currrent state for the requested tuples.
+	stateEntries, err := roomState.LoadStateAfterEventsForStringTuples(
+		ctx, prevStates, request.StateToFetch,
+	)
+	if err != nil {
+		return err
+	}
+
+	stateEvents, err := helpers.LoadStateEvents(ctx, r.DB, stateEntries)
+	if err != nil {
+		return err
+	}
+
+	for _, event := range stateEvents {
+		response.StateEvents = append(response.StateEvents, event.Headered(info.RoomVersion))
+	}
+
+	return nil
+}
+
+// QueryEventsByID implements api.RoomserverInternalAPI
+func (r *Queryer) QueryEventsByID(
+	ctx context.Context,
+	request *api.QueryEventsByIDRequest,
+	response *api.QueryEventsByIDResponse,
+) error {
+	eventNIDMap, err := r.DB.EventNIDs(ctx, request.EventIDs)
+	if err != nil {
+		return err
+	}
+
+	var eventNIDs []types.EventNID
+	for _, nid := range eventNIDMap {
+		eventNIDs = append(eventNIDs, nid)
+	}
+
+	events, err := helpers.LoadEvents(ctx, r.DB, eventNIDs)
+	if err != nil {
+		return err
+	}
+
+	for _, event := range events {
+		roomVersion, verr := r.roomVersion(event.RoomID())
+		if verr != nil {
+			return verr
+		}
+
+		response.Events = append(response.Events, event.Headered(roomVersion))
+	}
+
+	return nil
+}
+
+// QueryMembershipForUser implements api.RoomserverInternalAPI
+func (r *Queryer) QueryMembershipForUser(
+	ctx context.Context,
+	request *api.QueryMembershipForUserRequest,
+	response *api.QueryMembershipForUserResponse,
+) error {
+	info, err := r.DB.RoomInfo(ctx, request.RoomID)
+	if err != nil {
+		return err
+	}
+
+	membershipEventNID, stillInRoom, err := r.DB.GetMembership(ctx, info.RoomNID, request.UserID)
+	if err != nil {
+		return err
+	}
+
+	if membershipEventNID == 0 {
+		response.HasBeenInRoom = false
+		return nil
+	}
+
+	response.IsInRoom = stillInRoom
+	response.HasBeenInRoom = true
+
+	evs, err := r.DB.Events(ctx, []types.EventNID{membershipEventNID})
+	if err != nil {
+		return err
+	}
+	if len(evs) != 1 {
+		return fmt.Errorf("failed to load membership event for event NID %d", membershipEventNID)
+	}
+
+	response.EventID = evs[0].EventID()
+	response.Membership, err = evs[0].Membership()
+	return err
+}
+
+// QueryMembershipsForRoom implements api.RoomserverInternalAPI
+func (r *Queryer) QueryMembershipsForRoom(
+	ctx context.Context,
+	request *api.QueryMembershipsForRoomRequest,
+	response *api.QueryMembershipsForRoomResponse,
+) error {
+	info, err := r.DB.RoomInfo(ctx, request.RoomID)
+	if err != nil {
+		return err
+	}
+
+	membershipEventNID, stillInRoom, err := r.DB.GetMembership(ctx, info.RoomNID, request.Sender)
+	if err != nil {
+		return err
+	}
+
+	if membershipEventNID == 0 {
+		response.HasBeenInRoom = false
+		response.JoinEvents = nil
+		return nil
+	}
+
+	response.HasBeenInRoom = true
+	response.JoinEvents = []gomatrixserverlib.ClientEvent{}
+
+	var events []types.Event
+	var stateEntries []types.StateEntry
+	if stillInRoom {
+		var eventNIDs []types.EventNID
+		eventNIDs, err = r.DB.GetMembershipEventNIDsForRoom(ctx, info.RoomNID, request.JoinedOnly, false)
+		if err != nil {
+			return err
+		}
+
+		events, err = r.DB.Events(ctx, eventNIDs)
+	} else {
+		stateEntries, err = helpers.StateBeforeEvent(ctx, r.DB, *info, membershipEventNID)
+		if err != nil {
+			logrus.WithField("membership_event_nid", membershipEventNID).WithError(err).Error("failed to load state before event")
+			return err
+		}
+		events, err = helpers.GetMembershipsAtState(ctx, r.DB, stateEntries, request.JoinedOnly)
+	}
+
+	if err != nil {
+		return err
+	}
+
+	for _, event := range events {
+		clientEvent := gomatrixserverlib.ToClientEvent(event.Event, gomatrixserverlib.FormatAll)
+		response.JoinEvents = append(response.JoinEvents, clientEvent)
+	}
+
+	return nil
+}
+
+// QueryServerAllowedToSeeEvent implements api.RoomserverInternalAPI
+func (r *Queryer) QueryServerAllowedToSeeEvent(
+	ctx context.Context,
+	request *api.QueryServerAllowedToSeeEventRequest,
+	response *api.QueryServerAllowedToSeeEventResponse,
+) (err error) {
+	events, err := r.DB.EventsFromIDs(ctx, []string{request.EventID})
+	if err != nil {
+		return
+	}
+	if len(events) == 0 {
+		response.AllowedToSeeEvent = false // event doesn't exist so not allowed to see
+		return
+	}
+	roomID := events[0].RoomID()
+	isServerInRoom, err := helpers.IsServerCurrentlyInRoom(ctx, r.DB, request.ServerName, roomID)
+	if err != nil {
+		return
+	}
+	info, err := r.DB.RoomInfo(ctx, roomID)
+	if err != nil {
+		return err
+	}
+	if info == nil {
+		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,
+	)
+	return
+}
+
+// QueryMissingEvents implements api.RoomserverInternalAPI
+// nolint:gocyclo
+func (r *Queryer) QueryMissingEvents(
+	ctx context.Context,
+	request *api.QueryMissingEventsRequest,
+	response *api.QueryMissingEventsResponse,
+) error {
+	var front []string
+	eventsToFilter := make(map[string]bool, len(request.LatestEvents))
+	visited := make(map[string]bool, request.Limit) // request.Limit acts as a hint to size.
+	for _, id := range request.EarliestEvents {
+		visited[id] = true
+	}
+
+	for _, id := range request.LatestEvents {
+		if !visited[id] {
+			front = append(front, id)
+			eventsToFilter[id] = true
+		}
+	}
+	events, err := r.DB.EventsFromIDs(ctx, front)
+	if err != nil {
+		return err
+	}
+	if len(events) == 0 {
+		return nil // we are missing the events being asked to search from, give up.
+	}
+	info, err := r.DB.RoomInfo(ctx, events[0].RoomID())
+	if err != nil {
+		return err
+	}
+	if info == nil || info.IsStub {
+		return fmt.Errorf("missing RoomInfo for room %s", events[0].RoomID())
+	}
+
+	resultNIDs, err := helpers.ScanEventTree(ctx, r.DB, *info, front, visited, request.Limit, request.ServerName)
+	if err != nil {
+		return err
+	}
+
+	loadedEvents, err := helpers.LoadEvents(ctx, r.DB, resultNIDs)
+	if err != nil {
+		return err
+	}
+
+	response.Events = make([]gomatrixserverlib.HeaderedEvent, 0, len(loadedEvents)-len(eventsToFilter))
+	for _, event := range loadedEvents {
+		if !eventsToFilter[event.EventID()] {
+			roomVersion, verr := r.roomVersion(event.RoomID())
+			if verr != nil {
+				return verr
+			}
+
+			response.Events = append(response.Events, event.Headered(roomVersion))
+		}
+	}
+
+	return err
+}
+
+// QueryStateAndAuthChain implements api.RoomserverInternalAPI
+func (r *Queryer) QueryStateAndAuthChain(
+	ctx context.Context,
+	request *api.QueryStateAndAuthChainRequest,
+	response *api.QueryStateAndAuthChainResponse,
+) error {
+	info, err := r.DB.RoomInfo(ctx, request.RoomID)
+	if err != nil {
+		return err
+	}
+	if info == nil || info.IsStub {
+		return nil
+	}
+	response.RoomExists = true
+	response.RoomVersion = info.RoomVersion
+
+	stateEvents, err := r.loadStateAtEventIDs(ctx, *info, request.PrevEventIDs)
+	if err != nil {
+		return err
+	}
+	response.PrevEventsExist = true
+
+	// add the auth event IDs for the current state events too
+	var authEventIDs []string
+	authEventIDs = append(authEventIDs, request.AuthEventIDs...)
+	for _, se := range stateEvents {
+		authEventIDs = append(authEventIDs, se.AuthEventIDs()...)
+	}
+	authEventIDs = util.UniqueStrings(authEventIDs) // de-dupe
+
+	authEvents, err := getAuthChain(ctx, r.DB.EventsFromIDs, authEventIDs)
+	if err != nil {
+		return err
+	}
+
+	if request.ResolveState {
+		if stateEvents, err = state.ResolveConflictsAdhoc(
+			info.RoomVersion, stateEvents, authEvents,
+		); err != nil {
+			return err
+		}
+	}
+
+	for _, event := range stateEvents {
+		response.StateEvents = append(response.StateEvents, event.Headered(info.RoomVersion))
+	}
+
+	for _, event := range authEvents {
+		response.AuthChainEvents = append(response.AuthChainEvents, event.Headered(info.RoomVersion))
+	}
+
+	return err
+}
+
+func (r *Queryer) loadStateAtEventIDs(ctx context.Context, roomInfo types.RoomInfo, eventIDs []string) ([]gomatrixserverlib.Event, error) {
+	roomState := state.NewStateResolution(r.DB, roomInfo)
+	prevStates, err := r.DB.StateAtEventIDs(ctx, eventIDs)
+	if err != nil {
+		switch err.(type) {
+		case types.MissingEventError:
+			return nil, nil
+		default:
+			return nil, err
+		}
+	}
+
+	// Look up the currrent state for the requested tuples.
+	stateEntries, err := roomState.LoadCombinedStateAfterEvents(
+		ctx, prevStates,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return helpers.LoadStateEvents(ctx, r.DB, stateEntries)
+}
+
+type eventsFromIDs func(context.Context, []string) ([]types.Event, error)
+
+// getAuthChain fetches the auth chain for the given auth events. An auth chain
+// is the list of all events that are referenced in the auth_events section, and
+// all their auth_events, recursively. The returned set of events contain the
+// given events. Will *not* error if we don't have all auth events.
+func getAuthChain(
+	ctx context.Context, fn eventsFromIDs, authEventIDs []string,
+) ([]gomatrixserverlib.Event, error) {
+	// List of event IDs to fetch. On each pass, these events will be requested
+	// from the database and the `eventsToFetch` will be updated with any new
+	// events that we have learned about and need to find. When `eventsToFetch`
+	// is eventually empty, we should have reached the end of the chain.
+	eventsToFetch := authEventIDs
+	authEventsMap := make(map[string]gomatrixserverlib.Event)
+
+	for len(eventsToFetch) > 0 {
+		// Try to retrieve the events from the database.
+		events, err := fn(ctx, eventsToFetch)
+		if err != nil {
+			return nil, err
+		}
+
+		// We've now fetched these events so clear out `eventsToFetch`. Soon we may
+		// add newly discovered events to this for the next pass.
+		eventsToFetch = eventsToFetch[:0]
+
+		for _, event := range events {
+			// Store the event in the event map - this prevents us from requesting it
+			// from the database again.
+			authEventsMap[event.EventID()] = event.Event
+
+			// Extract all of the auth events from the newly obtained event. If we
+			// don't already have a record of the event, record it in the list of
+			// events we want to request for the next pass.
+			for _, authEvent := range event.AuthEvents() {
+				if _, ok := authEventsMap[authEvent.EventID]; !ok {
+					eventsToFetch = append(eventsToFetch, authEvent.EventID)
+				}
+			}
+		}
+	}
+
+	// We've now retrieved all of the events we can. Flatten them down into an
+	// array and return them.
+	var authEvents []gomatrixserverlib.Event
+	for _, event := range authEventsMap {
+		authEvents = append(authEvents, event)
+	}
+
+	return authEvents, nil
+}
+
+// QueryRoomVersionCapabilities implements api.RoomserverInternalAPI
+func (r *Queryer) QueryRoomVersionCapabilities(
+	ctx context.Context,
+	request *api.QueryRoomVersionCapabilitiesRequest,
+	response *api.QueryRoomVersionCapabilitiesResponse,
+) error {
+	response.DefaultRoomVersion = version.DefaultRoomVersion()
+	response.AvailableRoomVersions = make(map[gomatrixserverlib.RoomVersion]string)
+	for v, desc := range version.SupportedRoomVersions() {
+		if desc.Stable {
+			response.AvailableRoomVersions[v] = "stable"
+		} else {
+			response.AvailableRoomVersions[v] = "unstable"
+		}
+	}
+	return nil
+}
+
+// QueryRoomVersionCapabilities implements api.RoomserverInternalAPI
+func (r *Queryer) QueryRoomVersionForRoom(
+	ctx context.Context,
+	request *api.QueryRoomVersionForRoomRequest,
+	response *api.QueryRoomVersionForRoomResponse,
+) error {
+	if roomVersion, ok := r.Cache.GetRoomVersion(request.RoomID); ok {
+		response.RoomVersion = roomVersion
+		return nil
+	}
+
+	info, err := r.DB.RoomInfo(ctx, request.RoomID)
+	if err != nil {
+		return err
+	}
+	if info == nil {
+		return fmt.Errorf("QueryRoomVersionForRoom: missing room info for room %s", request.RoomID)
+	}
+	response.RoomVersion = info.RoomVersion
+	r.Cache.StoreRoomVersion(request.RoomID, response.RoomVersion)
+	return nil
+}
+
+func (r *Queryer) roomVersion(roomID string) (gomatrixserverlib.RoomVersion, error) {
+	var res api.QueryRoomVersionForRoomResponse
+	err := r.QueryRoomVersionForRoom(context.Background(), &api.QueryRoomVersionForRoomRequest{
+		RoomID: roomID,
+	}, &res)
+	return res.RoomVersion, err
+}
+
+func (r *Queryer) QueryPublishedRooms(
+	ctx context.Context,
+	req *api.QueryPublishedRoomsRequest,
+	res *api.QueryPublishedRoomsResponse,
+) error {
+	rooms, err := r.DB.GetPublishedRooms(ctx)
+	if err != nil {
+		return err
+	}
+	res.RoomIDs = rooms
+	return nil
+}
+
+func (r *Queryer) QueryCurrentState(ctx context.Context, req *api.QueryCurrentStateRequest, res *api.QueryCurrentStateResponse) error {
+	res.StateEvents = make(map[gomatrixserverlib.StateKeyTuple]*gomatrixserverlib.HeaderedEvent)
+	for _, tuple := range req.StateTuples {
+		ev, err := r.DB.GetStateEvent(ctx, req.RoomID, tuple.EventType, tuple.StateKey)
+		if err != nil {
+			return err
+		}
+		if ev != nil {
+			res.StateEvents[tuple] = ev
+		}
+	}
+	return nil
+}
+
+func (r *Queryer) QueryRoomsForUser(ctx context.Context, req *api.QueryRoomsForUserRequest, res *api.QueryRoomsForUserResponse) error {
+	roomIDs, err := r.DB.GetRoomsByMembership(ctx, req.UserID, req.WantMembership)
+	if err != nil {
+		return err
+	}
+	res.RoomIDs = roomIDs
+	return nil
+}
+
+func (r *Queryer) QueryKnownUsers(ctx context.Context, req *api.QueryKnownUsersRequest, res *api.QueryKnownUsersResponse) error {
+	users, err := r.DB.GetKnownUsers(ctx, req.UserID, req.SearchString, req.Limit)
+	if err != nil {
+		return err
+	}
+	for _, user := range users {
+		res.Users = append(res.Users, authtypes.FullyQualifiedProfile{
+			UserID: user,
+		})
+	}
+	return nil
+}
+
+func (r *Queryer) QueryBulkStateContent(ctx context.Context, req *api.QueryBulkStateContentRequest, res *api.QueryBulkStateContentResponse) error {
+	events, err := r.DB.GetBulkStateContent(ctx, req.RoomIDs, req.StateTuples, req.AllowWildcards)
+	if err != nil {
+		return err
+	}
+	res.Rooms = make(map[string]map[gomatrixserverlib.StateKeyTuple]string)
+	for _, ev := range events {
+		if res.Rooms[ev.RoomID] == nil {
+			res.Rooms[ev.RoomID] = make(map[gomatrixserverlib.StateKeyTuple]string)
+		}
+		room := res.Rooms[ev.RoomID]
+		room[gomatrixserverlib.StateKeyTuple{
+			EventType: ev.EventType,
+			StateKey:  ev.StateKey,
+		}] = ev.ContentValue
+		res.Rooms[ev.RoomID] = room
+	}
+	return nil
+}
+
+func (r *Queryer) QuerySharedUsers(ctx context.Context, req *api.QuerySharedUsersRequest, res *api.QuerySharedUsersResponse) error {
+	roomIDs, err := r.DB.GetRoomsByMembership(ctx, req.UserID, "join")
+	if err != nil {
+		return err
+	}
+	roomIDs = append(roomIDs, req.IncludeRoomIDs...)
+	excludeMap := make(map[string]bool)
+	for _, roomID := range req.ExcludeRoomIDs {
+		excludeMap[roomID] = true
+	}
+	// filter out excluded rooms
+	j := 0
+	for i := range roomIDs {
+		// move elements to include to the beginning of the slice
+		// then trim elements on the right
+		if !excludeMap[roomIDs[i]] {
+			roomIDs[j] = roomIDs[i]
+			j++
+		}
+	}
+	roomIDs = roomIDs[:j]
+
+	users, err := r.DB.JoinedUsersSetInRooms(ctx, roomIDs)
+	if err != nil {
+		return err
+	}
+	res.UserIDsToCount = users
+	return nil
+}
+
+func (r *Queryer) QueryServerBannedFromRoom(ctx context.Context, req *api.QueryServerBannedFromRoomRequest, res *api.QueryServerBannedFromRoomResponse) error {
+	if r.ServerACLs == nil {
+		return errors.New("no server ACL tracking")
+	}
+	res.Banned = r.ServerACLs.IsServerBannedFromRoom(req.ServerName, req.RoomID)
+	return nil
+}

roomserver/internal/query/query_test.go

@@ -1,4 +1,4 @@
-// Copyright 2017 Vector Creations Ltd
+// Copyright 2020 The Matrix.org Foundation C.I.C.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package internal
+package query
 
 import (
 	"context"

roomserver/inthttp/client.go

@@ -44,6 +44,12 @@ const (
 	RoomserverQueryRoomVersionCapabilitiesPath = "/roomserver/queryRoomVersionCapabilities"
 	RoomserverQueryRoomVersionForRoomPath      = "/roomserver/queryRoomVersionForRoom"
 	RoomserverQueryPublishedRoomsPath          = "/roomserver/queryPublishedRooms"
+	RoomserverQueryCurrentStatePath            = "/roomserver/queryCurrentState"
+	RoomserverQueryRoomsForUserPath            = "/roomserver/queryRoomsForUser"
+	RoomserverQueryBulkStateContentPath        = "/roomserver/queryBulkStateContent"
+	RoomserverQuerySharedUsersPath             = "/roomserver/querySharedUsers"
+	RoomserverQueryKnownUsersPath              = "/roomserver/queryKnownUsers"
+	RoomserverQueryServerBannedFromRoomPath    = "/roomserver/queryServerBannedFromRoom"
 )
 
 type httpRoomserverInternalAPI struct {
@@ -389,3 +395,69 @@ func (h *httpRoomserverInternalAPI) QueryRoomVersionForRoom(
 	}
 	return err
 }
+
+func (h *httpRoomserverInternalAPI) QueryCurrentState(
+	ctx context.Context,
+	request *api.QueryCurrentStateRequest,
+	response *api.QueryCurrentStateResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryCurrentState")
+	defer span.Finish()
+
+	apiURL := h.roomserverURL + RoomserverQueryCurrentStatePath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+}
+
+func (h *httpRoomserverInternalAPI) QueryRoomsForUser(
+	ctx context.Context,
+	request *api.QueryRoomsForUserRequest,
+	response *api.QueryRoomsForUserResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryRoomsForUser")
+	defer span.Finish()
+
+	apiURL := h.roomserverURL + RoomserverQueryRoomsForUserPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+}
+
+func (h *httpRoomserverInternalAPI) QueryBulkStateContent(
+	ctx context.Context,
+	request *api.QueryBulkStateContentRequest,
+	response *api.QueryBulkStateContentResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryBulkStateContent")
+	defer span.Finish()
+
+	apiURL := h.roomserverURL + RoomserverQueryBulkStateContentPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+}
+
+func (h *httpRoomserverInternalAPI) QuerySharedUsers(
+	ctx context.Context, req *api.QuerySharedUsersRequest, res *api.QuerySharedUsersResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QuerySharedUsers")
+	defer span.Finish()
+
+	apiURL := h.roomserverURL + RoomserverQuerySharedUsersPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
+}
+
+func (h *httpRoomserverInternalAPI) QueryKnownUsers(
+	ctx context.Context, req *api.QueryKnownUsersRequest, res *api.QueryKnownUsersResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryKnownUsers")
+	defer span.Finish()
+
+	apiURL := h.roomserverURL + RoomserverQueryKnownUsersPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
+}
+
+func (h *httpRoomserverInternalAPI) QueryServerBannedFromRoom(
+	ctx context.Context, req *api.QueryServerBannedFromRoomRequest, res *api.QueryServerBannedFromRoomResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryServerBannedFromRoom")
+	defer span.Finish()
+
+	apiURL := h.roomserverURL + RoomserverQueryServerBannedFromRoomPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
+}

roomserver/inthttp/server.go

@@ -312,4 +312,82 @@ func AddRoutes(r api.RoomserverInternalAPI, internalAPIMux *mux.Router) {
 			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
 		}),
 	)
+	internalAPIMux.Handle(RoomserverQueryCurrentStatePath,
+		httputil.MakeInternalAPI("queryCurrentState", func(req *http.Request) util.JSONResponse {
+			request := api.QueryCurrentStateRequest{}
+			response := api.QueryCurrentStateResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			if err := r.QueryCurrentState(req.Context(), &request, &response); err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
+	internalAPIMux.Handle(RoomserverQueryRoomsForUserPath,
+		httputil.MakeInternalAPI("queryRoomsForUser", func(req *http.Request) util.JSONResponse {
+			request := api.QueryRoomsForUserRequest{}
+			response := api.QueryRoomsForUserResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			if err := r.QueryRoomsForUser(req.Context(), &request, &response); err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
+	internalAPIMux.Handle(RoomserverQueryBulkStateContentPath,
+		httputil.MakeInternalAPI("queryBulkStateContent", func(req *http.Request) util.JSONResponse {
+			request := api.QueryBulkStateContentRequest{}
+			response := api.QueryBulkStateContentResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			if err := r.QueryBulkStateContent(req.Context(), &request, &response); err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
+	internalAPIMux.Handle(RoomserverQuerySharedUsersPath,
+		httputil.MakeInternalAPI("querySharedUsers", func(req *http.Request) util.JSONResponse {
+			request := api.QuerySharedUsersRequest{}
+			response := api.QuerySharedUsersResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			if err := r.QuerySharedUsers(req.Context(), &request, &response); err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
+	internalAPIMux.Handle(RoomserverQuerySharedUsersPath,
+		httputil.MakeInternalAPI("queryKnownUsers", func(req *http.Request) util.JSONResponse {
+			request := api.QueryKnownUsersRequest{}
+			response := api.QueryKnownUsersResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			if err := r.QueryKnownUsers(req.Context(), &request, &response); err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
+	internalAPIMux.Handle(RoomserverQueryServerBannedFromRoomPath,
+		httputil.MakeInternalAPI("queryServerBannedFromRoom", func(req *http.Request) util.JSONResponse {
+			request := api.QueryServerBannedFromRoomRequest{}
+			response := api.QueryServerBannedFromRoomResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			if err := r.QueryServerBannedFromRoom(req.Context(), &request, &response); err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
 }

roomserver/roomserver.go

@@ -38,7 +38,6 @@ func AddInternalRoutes(router *mux.Router, intAPI api.RoomserverInternalAPI) {
 func NewInternalAPI(
 	base *setup.BaseDendrite,
 	keyRing gomatrixserverlib.JSONVerifier,
-	fedClient *gomatrixserverlib.FederationClient,
 ) api.RoomserverInternalAPI {
 	cfg := &base.Cfg.RoomServer
 
@@ -47,14 +46,8 @@ func NewInternalAPI(
 		logrus.WithError(err).Panicf("failed to connect to room server db")
 	}
 
-	return &internal.RoomserverInternalAPI{
-		DB:                   roomserverDB,
-		Cfg:                  cfg,
-		Producer:             base.KafkaProducer,
-		OutputRoomEventTopic: string(cfg.Matrix.Kafka.TopicFor(config.TopicOutputRoomEvent)),
-		Cache:                base.Caches,
-		ServerName:           cfg.Matrix.ServerName,
-		FedClient:            fedClient,
-		KeyRing:              keyRing,
-	}
+	return internal.NewRoomserverAPI(
+		cfg, roomserverDB, base.KafkaProducer, string(cfg.Matrix.Kafka.TopicFor(config.TopicOutputRoomEvent)),
+		base.Caches, keyRing,
+	)
 }

roomserver/roomserver_test.go

@@ -112,10 +112,9 @@ func mustSendEvents(t *testing.T, ver gomatrixserverlib.RoomVersion, events []js
 		Cfg:           cfg,
 	}
 
-	rsAPI := NewInternalAPI(base, &test.NopJSONVerifier{}, nil)
+	rsAPI := NewInternalAPI(base, &test.NopJSONVerifier{})
 	hevents := mustLoadEvents(t, ver, events)
-	_, err = api.SendEvents(ctx, rsAPI, hevents, testOrigin, nil)
-	if err != nil {
+	if err = api.SendEvents(ctx, rsAPI, hevents, testOrigin, nil); err != nil {
 		t.Errorf("failed to SendEvents: %s", err)
 	}
 	return rsAPI, dp, hevents

roomserver/state/state.go

@@ -31,12 +31,14 @@ import (
 )
 
 type StateResolution struct {
-	db storage.Database
+	db       storage.Database
+	roomInfo types.RoomInfo
 }
 
-func NewStateResolution(db storage.Database) StateResolution {
+func NewStateResolution(db storage.Database, roomInfo types.RoomInfo) StateResolution {
 	return StateResolution{
-		db: db,
+		db:       db,
+		roomInfo: roomInfo,
 	}
 }
 
@@ -339,7 +341,7 @@ func (v StateResolution) loadStateAtSnapshotForNumericTuples(
 // This is typically the state before an event.
 // Returns a sorted list of state entries or an error if there was a problem talking to the database.
 func (v StateResolution) LoadStateAfterEventsForStringTuples(
-	ctx context.Context, roomNID types.RoomNID,
+	ctx context.Context,
 	prevStates []types.StateAtEvent,
 	stateKeyTuples []gomatrixserverlib.StateKeyTuple,
 ) ([]types.StateEntry, error) {
@@ -347,24 +349,18 @@ func (v StateResolution) LoadStateAfterEventsForStringTuples(
 	if err != nil {
 		return nil, err
 	}
-	return v.loadStateAfterEventsForNumericTuples(ctx, roomNID, prevStates, numericTuples)
+	return v.loadStateAfterEventsForNumericTuples(ctx, prevStates, numericTuples)
 }
 
 func (v StateResolution) loadStateAfterEventsForNumericTuples(
-	ctx context.Context, roomNID types.RoomNID,
+	ctx context.Context,
 	prevStates []types.StateAtEvent,
 	stateKeyTuples []types.StateKeyTuple,
 ) ([]types.StateEntry, error) {
-	roomVersion, err := v.db.GetRoomVersionForRoomNID(ctx, roomNID)
-	if err != nil {
-		return nil, err
-	}
-
 	if len(prevStates) == 1 {
 		// Fast path for a single event.
 		prevState := prevStates[0]
-		var result []types.StateEntry
-		result, err = v.loadStateAtSnapshotForNumericTuples(
+		result, err := v.loadStateAtSnapshotForNumericTuples(
 			ctx, prevState.BeforeStateSnapshotNID, stateKeyTuples,
 		)
 		if err != nil {
@@ -403,7 +399,7 @@ func (v StateResolution) loadStateAfterEventsForNumericTuples(
 
 	// TODO: Add metrics for this as it could take a long time for big rooms
 	// with large conflicts.
-	fullState, _, _, err := v.calculateStateAfterManyEvents(ctx, roomVersion, prevStates)
+	fullState, _, _, err := v.calculateStateAfterManyEvents(ctx, v.roomInfo.RoomVersion, prevStates)
 	if err != nil {
 		return nil, err
 	}
@@ -527,7 +523,6 @@ func init() {
 func (v StateResolution) CalculateAndStoreStateBeforeEvent(
 	ctx context.Context,
 	event gomatrixserverlib.Event,
-	roomNID types.RoomNID,
 ) (types.StateSnapshotNID, error) {
 	// Load the state at the prev events.
 	prevEventRefs := event.PrevEvents()
@@ -542,14 +537,13 @@ func (v StateResolution) CalculateAndStoreStateBeforeEvent(
 	}
 
 	// The state before this event will be the state after the events that came before it.
-	return v.CalculateAndStoreStateAfterEvents(ctx, roomNID, prevStates)
+	return v.CalculateAndStoreStateAfterEvents(ctx, prevStates)
 }
 
 // CalculateAndStoreStateAfterEvents finds the room state after the given events.
 // Stores the resulting state in the database and returns a numeric ID for that snapshot.
 func (v StateResolution) CalculateAndStoreStateAfterEvents(
 	ctx context.Context,
-	roomNID types.RoomNID,
 	prevStates []types.StateAtEvent,
 ) (types.StateSnapshotNID, error) {
 	metrics := calculateStateMetrics{startTime: time.Now(), prevEventLength: len(prevStates)}
@@ -558,7 +552,7 @@ func (v StateResolution) CalculateAndStoreStateAfterEvents(
 		// 2) There weren't any prev_events for this event so the state is
 		// empty.
 		metrics.algorithm = "empty_state"
-		stateNID, err := v.db.AddState(ctx, roomNID, nil, nil)
+		stateNID, err := v.db.AddState(ctx, v.roomInfo.RoomNID, nil, nil)
 		if err != nil {
 			err = fmt.Errorf("v.db.AddState: %w", err)
 		}
@@ -590,7 +584,7 @@ func (v StateResolution) CalculateAndStoreStateAfterEvents(
 			// add the state event as a block of size one to the end of the blocks.
 			metrics.algorithm = "single_delta"
 			stateNID, err := v.db.AddState(
-				ctx, roomNID, stateBlockNIDs, []types.StateEntry{prevState.StateEntry},
+				ctx, v.roomInfo.RoomNID, stateBlockNIDs, []types.StateEntry{prevState.StateEntry},
 			)
 			if err != nil {
 				err = fmt.Errorf("v.db.AddState: %w", err)
@@ -601,7 +595,7 @@ func (v StateResolution) CalculateAndStoreStateAfterEvents(
 		// So fall through to calculateAndStoreStateAfterManyEvents
 	}
 
-	stateNID, err := v.calculateAndStoreStateAfterManyEvents(ctx, roomNID, prevStates, metrics)
+	stateNID, err := v.calculateAndStoreStateAfterManyEvents(ctx, v.roomInfo.RoomNID, prevStates, metrics)
 	if err != nil {
 		return 0, fmt.Errorf("v.calculateAndStoreStateAfterManyEvents: %w", err)
 	}
@@ -624,13 +618,8 @@ func (v StateResolution) calculateAndStoreStateAfterManyEvents(
 	prevStates []types.StateAtEvent,
 	metrics calculateStateMetrics,
 ) (types.StateSnapshotNID, error) {
-	roomVersion, err := v.db.GetRoomVersionForRoomNID(ctx, roomNID)
-	if err != nil {
-		return metrics.stop(0, err)
-	}
-
 	state, algorithm, conflictLength, err :=
-		v.calculateStateAfterManyEvents(ctx, roomVersion, prevStates)
+		v.calculateStateAfterManyEvents(ctx, v.roomInfo.RoomVersion, prevStates)
 	metrics.algorithm = algorithm
 	if err != nil {
 		return metrics.stop(0, err)

roomserver/storage/interface.go

@@ -17,6 +17,7 @@ package storage
 import (
 	"context"
 
+	"github.com/matrix-org/dendrite/currentstateserver/storage/tables"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/roomserver/storage/shared"
 	"github.com/matrix-org/dendrite/roomserver/types"
@@ -66,8 +67,6 @@ type Database interface {
 	Events(ctx context.Context, eventNIDs []types.EventNID) ([]types.Event, error)
 	// Look up snapshot NID for an event ID string
 	SnapshotNIDFromEventID(ctx context.Context, eventID string) (types.StateSnapshotNID, error)
-	// Look up a room version from the room NID.
-	GetRoomVersionForRoomNID(ctx context.Context, roomNID types.RoomNID) (gomatrixserverlib.RoomVersion, error)
 	// Stores a matrix room event in the database. Returns the room NID, the state snapshot and the redacted event ID if any, or an error.
 	StoreEvent(
 		ctx context.Context, event gomatrixserverlib.Event, txnAndSessionID *api.TransactionID, authEventNIDs []types.EventNID,
@@ -91,7 +90,7 @@ type Database interface {
 	// The RoomRecentEventsUpdater must have Commit or Rollback called on it if this doesn't return an error.
 	// Returns the latest events in the room and the last eventID sent to the log along with an updater.
 	// If this returns an error then no further action is required.
-	GetLatestEventsForUpdate(ctx context.Context, roomNID types.RoomNID) (*shared.LatestEventsUpdater, error)
+	GetLatestEventsForUpdate(ctx context.Context, roomInfo types.RoomInfo) (*shared.LatestEventsUpdater, error)
 	// Look up event ID by transaction's info.
 	// This is used to determine if the room event is processed/processing already.
 	// Returns an empty string if no such event exists.
@@ -136,10 +135,26 @@ type Database interface {
 	// not found.
 	// Returns an error if the retrieval went wrong.
 	EventsFromIDs(ctx context.Context, eventIDs []string) ([]types.Event, error)
-	// Look up the room version for a given room.
-	GetRoomVersionForRoom(ctx context.Context, roomID string) (gomatrixserverlib.RoomVersion, error)
 	// Publish or unpublish a room from the room directory.
 	PublishRoom(ctx context.Context, roomID string, publish bool) error
 	// Returns a list of room IDs for rooms which are published.
 	GetPublishedRooms(ctx context.Context) ([]string, error)
+
+	// TODO: factor out - from currentstateserver
+
+	// GetStateEvent returns the state event of a given type for a given room with a given state key
+	// If no event could be found, returns nil
+	// If there was an issue during the retrieval, returns an error
+	GetStateEvent(ctx context.Context, roomID, evType, stateKey string) (*gomatrixserverlib.HeaderedEvent, error)
+	// GetRoomsByMembership returns a list of room IDs matching the provided membership and user ID (as state_key).
+	GetRoomsByMembership(ctx context.Context, userID, membership string) ([]string, error)
+	// GetBulkStateContent returns all state events which match a given room ID and a given state key tuple. Both must be satisfied for a match.
+	// If a tuple has the StateKey of '*' and allowWildcards=true then all state events with the EventType should be returned.
+	GetBulkStateContent(ctx context.Context, roomIDs []string, tuples []gomatrixserverlib.StateKeyTuple, allowWildcards bool) ([]tables.StrippedEvent, error)
+	// JoinedUsersSetInRooms returns all joined users in the rooms given, along with the count of how many times they appear.
+	JoinedUsersSetInRooms(ctx context.Context, roomIDs []string) (map[string]int, error)
+	// GetKnownUsers searches all users that userID knows about.
+	GetKnownUsers(ctx context.Context, userID, searchString string, limit int) ([]string, error)
+	// GetKnownRooms returns a list of all rooms we know about.
+	GetKnownRooms(ctx context.Context) ([]string, error)
 }

roomserver/storage/postgres/membership_table.go

@@ -18,7 +18,9 @@ package postgres
 import (
 	"context"
 	"database/sql"
+	"fmt"
 
+	"github.com/lib/pq"
 	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/roomserver/storage/shared"
@@ -62,6 +64,10 @@ CREATE TABLE IF NOT EXISTS roomserver_membership (
 );
 `
 
+var selectJoinedUsersSetForRoomsSQL = "" +
+	"SELECT target_nid, COUNT(room_nid) FROM roomserver_membership WHERE room_nid = ANY($1) AND" +
+	" membership_nid = " + fmt.Sprintf("%d", tables.MembershipStateJoin) + " GROUP BY target_nid"
+
 // Insert a row in to membership table so that it can be locked by the
 // SELECT FOR UPDATE
 const insertMembershipSQL = "" +
@@ -99,6 +105,19 @@ const updateMembershipSQL = "" +
 	"UPDATE roomserver_membership SET sender_nid = $3, membership_nid = $4, event_nid = $5" +
 	" WHERE room_nid = $1 AND target_nid = $2"
 
+const selectRoomsWithMembershipSQL = "" +
+	"SELECT room_nid FROM roomserver_membership WHERE membership_nid = $1 AND target_nid = $2"
+
+// selectKnownUsersSQL uses a sub-select statement here to find rooms that the user is
+// joined to. Since this information is used to populate the user directory, we will
+// only return users that the user would ordinarily be able to see anyway.
+var selectKnownUsersSQL = "" +
+	"SELECT DISTINCT event_state_key FROM roomserver_membership INNER JOIN roomserver_event_state_keys ON " +
+	"roomserver_membership.target_nid = roomserver_event_state_keys.event_state_key_nid" +
+	" WHERE room_nid = ANY(" +
+	"  SELECT DISTINCT room_nid FROM roomserver_membership WHERE target_nid=$1 AND membership_nid = " + fmt.Sprintf("%d", tables.MembershipStateJoin) +
+	") AND membership_nid = " + fmt.Sprintf("%d", tables.MembershipStateJoin) + " AND event_state_key LIKE $2 LIMIT $3"
+
 type membershipStatements struct {
 	insertMembershipStmt                            *sql.Stmt
 	selectMembershipForUpdateStmt                   *sql.Stmt
@@ -108,6 +127,9 @@ type membershipStatements struct {
 	selectMembershipsFromRoomStmt                   *sql.Stmt
 	selectLocalMembershipsFromRoomStmt              *sql.Stmt
 	updateMembershipStmt                            *sql.Stmt
+	selectRoomsWithMembershipStmt                   *sql.Stmt
+	selectJoinedUsersSetForRoomsStmt                *sql.Stmt
+	selectKnownUsersStmt                            *sql.Stmt
 }
 
 func NewPostgresMembershipTable(db *sql.DB) (tables.Membership, error) {
@@ -126,6 +148,9 @@ func NewPostgresMembershipTable(db *sql.DB) (tables.Membership, error) {
 		{&s.selectMembershipsFromRoomStmt, selectMembershipsFromRoomSQL},
 		{&s.selectLocalMembershipsFromRoomStmt, selectLocalMembershipsFromRoomSQL},
 		{&s.updateMembershipStmt, updateMembershipSQL},
+		{&s.selectRoomsWithMembershipStmt, selectRoomsWithMembershipSQL},
+		{&s.selectJoinedUsersSetForRoomsStmt, selectJoinedUsersSetForRoomsSQL},
+		{&s.selectKnownUsersStmt, selectKnownUsersSQL},
 	}.Prepare(db)
 }
 
@@ -222,3 +247,61 @@ func (s *membershipStatements) UpdateMembership(
 	)
 	return err
 }
+
+func (s *membershipStatements) SelectRoomsWithMembership(
+	ctx context.Context, userID types.EventStateKeyNID, membershipState tables.MembershipState,
+) ([]types.RoomNID, error) {
+	rows, err := s.selectRoomsWithMembershipStmt.QueryContext(ctx, membershipState, userID)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "SelectRoomsWithMembership: rows.close() failed")
+	var roomNIDs []types.RoomNID
+	for rows.Next() {
+		var roomNID types.RoomNID
+		if err := rows.Scan(&roomNID); err != nil {
+			return nil, err
+		}
+		roomNIDs = append(roomNIDs, roomNID)
+	}
+	return roomNIDs, nil
+}
+
+func (s *membershipStatements) SelectJoinedUsersSetForRooms(ctx context.Context, roomNIDs []types.RoomNID) (map[types.EventStateKeyNID]int, error) {
+	roomIDarray := make([]int64, len(roomNIDs))
+	for i := range roomNIDs {
+		roomIDarray[i] = int64(roomNIDs[i])
+	}
+	rows, err := s.selectJoinedUsersSetForRoomsStmt.QueryContext(ctx, pq.Int64Array(roomIDarray))
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectJoinedUsersSetForRooms: rows.close() failed")
+	result := make(map[types.EventStateKeyNID]int)
+	for rows.Next() {
+		var userID types.EventStateKeyNID
+		var count int
+		if err := rows.Scan(&userID, &count); err != nil {
+			return nil, err
+		}
+		result[userID] = count
+	}
+	return result, rows.Err()
+}
+
+func (s *membershipStatements) SelectKnownUsers(ctx context.Context, userID types.EventStateKeyNID, searchString string, limit int) ([]string, error) {
+	rows, err := s.selectKnownUsersStmt.QueryContext(ctx, userID, fmt.Sprintf("%%%s%%", searchString), limit)
+	if err != nil {
+		return nil, err
+	}
+	result := []string{}
+	defer internal.CloseAndLogIfError(ctx, rows, "SelectKnownUsers: rows.close() failed")
+	for rows.Next() {
+		var userID string
+		if err := rows.Scan(&userID); err != nil {
+			return nil, err
+		}
+		result = append(result, userID)
+	}
+	return result, rows.Err()
+}

roomserver/storage/postgres/rooms_table.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 
 	"github.com/lib/pq"
+	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/roomserver/storage/shared"
 	"github.com/matrix-org/dendrite/roomserver/storage/tables"
@@ -68,24 +69,32 @@ 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"
 
 const selectRoomInfoSQL = "" +
 	"SELECT room_version, room_nid, state_snapshot_nid, latest_event_nids FROM roomserver_rooms WHERE room_id = $1"
 
+const selectRoomIDsSQL = "" +
+	"SELECT room_id FROM roomserver_rooms"
+
+const bulkSelectRoomIDsSQL = "" +
+	"SELECT room_id FROM roomserver_rooms WHERE room_nid IN ($1)"
+
+const bulkSelectRoomNIDsSQL = "" +
+	"SELECT room_nid FROM roomserver_rooms WHERE room_id IN ($1)"
+
 type roomStatements struct {
 	insertRoomNIDStmt                  *sql.Stmt
 	selectRoomNIDStmt                  *sql.Stmt
 	selectLatestEventNIDsStmt          *sql.Stmt
 	selectLatestEventNIDsForUpdateStmt *sql.Stmt
 	updateLatestEventNIDsStmt          *sql.Stmt
-	selectRoomVersionForRoomIDStmt     *sql.Stmt
 	selectRoomVersionForRoomNIDStmt    *sql.Stmt
 	selectRoomInfoStmt                 *sql.Stmt
+	selectRoomIDsStmt                  *sql.Stmt
+	bulkSelectRoomIDsStmt              *sql.Stmt
+	bulkSelectRoomNIDsStmt             *sql.Stmt
 }
 
 func NewPostgresRoomsTable(db *sql.DB) (tables.Rooms, error) {
@@ -100,12 +109,30 @@ func NewPostgresRoomsTable(db *sql.DB) (tables.Rooms, error) {
 		{&s.selectLatestEventNIDsStmt, selectLatestEventNIDsSQL},
 		{&s.selectLatestEventNIDsForUpdateStmt, selectLatestEventNIDsForUpdateSQL},
 		{&s.updateLatestEventNIDsStmt, updateLatestEventNIDsSQL},
-		{&s.selectRoomVersionForRoomIDStmt, selectRoomVersionForRoomIDSQL},
 		{&s.selectRoomVersionForRoomNIDStmt, selectRoomVersionForRoomNIDSQL},
 		{&s.selectRoomInfoStmt, selectRoomInfoSQL},
+		{&s.selectRoomIDsStmt, selectRoomIDsSQL},
+		{&s.bulkSelectRoomIDsStmt, bulkSelectRoomIDsSQL},
+		{&s.bulkSelectRoomNIDsStmt, bulkSelectRoomNIDsSQL},
 	}.Prepare(db)
 }
 
+func (s *roomStatements) SelectRoomIDs(ctx context.Context) ([]string, error) {
+	rows, err := s.selectRoomIDsStmt.QueryContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectRoomIDsStmt: rows.close() failed")
+	var roomIDs []string
+	for rows.Next() {
+		var roomID string
+		if err = rows.Scan(&roomID); err != nil {
+			return nil, err
+		}
+		roomIDs = append(roomIDs, roomID)
+	}
+	return roomIDs, nil
+}
 func (s *roomStatements) InsertRoomNID(
 	ctx context.Context, txn *sql.Tx,
 	roomID string, roomVersion gomatrixserverlib.RoomVersion,
@@ -192,18 +219,6 @@ 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 := sqlutil.TxStmt(txn, s.selectRoomVersionForRoomIDStmt)
-	err := stmt.QueryRowContext(ctx, roomID).Scan(&roomVersion)
-	if err == sql.ErrNoRows {
-		return roomVersion, errors.New("room not found")
-	}
-	return roomVersion, err
-}
-
 func (s *roomStatements) SelectRoomVersionForRoomNID(
 	ctx context.Context, roomNID types.RoomNID,
 ) (gomatrixserverlib.RoomVersion, error) {
@@ -214,3 +229,45 @@ func (s *roomStatements) SelectRoomVersionForRoomNID(
 	}
 	return roomVersion, err
 }
+
+func (s *roomStatements) BulkSelectRoomIDs(ctx context.Context, roomNIDs []types.RoomNID) ([]string, error) {
+	var array pq.Int64Array
+	for _, nid := range roomNIDs {
+		array = append(array, int64(nid))
+	}
+	rows, err := s.bulkSelectRoomIDsStmt.QueryContext(ctx, array)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "bulkSelectRoomIDsStmt: rows.close() failed")
+	var roomIDs []string
+	for rows.Next() {
+		var roomID string
+		if err = rows.Scan(&roomID); err != nil {
+			return nil, err
+		}
+		roomIDs = append(roomIDs, roomID)
+	}
+	return roomIDs, nil
+}
+
+func (s *roomStatements) BulkSelectRoomNIDs(ctx context.Context, roomIDs []string) ([]types.RoomNID, error) {
+	var array pq.StringArray
+	for _, roomID := range roomIDs {
+		array = append(array, roomID)
+	}
+	rows, err := s.bulkSelectRoomNIDsStmt.QueryContext(ctx, array)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "bulkSelectRoomNIDsStmt: rows.close() failed")
+	var roomNIDs []types.RoomNID
+	for rows.Next() {
+		var roomNID types.RoomNID
+		if err = rows.Scan(&roomNID); err != nil {
+			return nil, err
+		}
+		roomNIDs = append(roomNIDs, roomNID)
+	}
+	return roomNIDs, nil
+}

roomserver/storage/shared/latest_events_updater.go

@@ -12,15 +12,15 @@ import (
 type LatestEventsUpdater struct {
 	transaction
 	d                       *Database
-	roomNID                 types.RoomNID
+	roomInfo                types.RoomInfo
 	latestEvents            []types.StateAtEventAndReference
 	lastEventIDSent         string
 	currentStateSnapshotNID types.StateSnapshotNID
 }
 
-func NewLatestEventsUpdater(ctx context.Context, d *Database, txn *sql.Tx, roomNID types.RoomNID) (*LatestEventsUpdater, error) {
+func NewLatestEventsUpdater(ctx context.Context, d *Database, txn *sql.Tx, roomInfo types.RoomInfo) (*LatestEventsUpdater, error) {
 	eventNIDs, lastEventNIDSent, currentStateSnapshotNID, err :=
-		d.RoomsTable.SelectLatestEventsNIDsForUpdate(ctx, txn, roomNID)
+		d.RoomsTable.SelectLatestEventsNIDsForUpdate(ctx, txn, roomInfo.RoomNID)
 	if err != nil {
 		txn.Rollback() // nolint: errcheck
 		return nil, err
@@ -39,14 +39,13 @@ func NewLatestEventsUpdater(ctx context.Context, d *Database, txn *sql.Tx, roomN
 		}
 	}
 	return &LatestEventsUpdater{
-		transaction{ctx, txn}, d, roomNID, stateAndRefs, lastEventIDSent, currentStateSnapshotNID,
+		transaction{ctx, txn}, d, roomInfo, stateAndRefs, lastEventIDSent, currentStateSnapshotNID,
 	}, nil
 }
 
 // RoomVersion implements types.RoomRecentEventsUpdater
 func (u *LatestEventsUpdater) RoomVersion() (version gomatrixserverlib.RoomVersion) {
-	version, _ = u.d.GetRoomVersionForRoomNID(u.ctx, u.roomNID)
-	return
+	return u.roomInfo.RoomVersion
 }
 
 // LatestEvents implements types.RoomRecentEventsUpdater
@@ -118,5 +117,5 @@ func (u *LatestEventsUpdater) MarkEventAsSent(eventNID types.EventNID) error {
 }
 
 func (u *LatestEventsUpdater) MembershipUpdater(targetUserNID types.EventStateKeyNID, targetLocal bool) (*MembershipUpdater, error) {
-	return u.d.membershipUpdaterTxn(u.ctx, u.txn, u.roomNID, targetUserNID, targetLocal)
+	return u.d.membershipUpdaterTxn(u.ctx, u.txn, u.roomInfo.RoomNID, targetUserNID, targetLocal)
 }

roomserver/storage/shared/storage.go

@@ -5,13 +5,16 @@ import (
 	"database/sql"
 	"encoding/json"
 	"fmt"
+	"sort"
 
+	csstables "github.com/matrix-org/dendrite/currentstateserver/storage/tables"
 	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/roomserver/storage/tables"
 	"github.com/matrix-org/dendrite/roomserver/types"
 	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
 	"github.com/tidwall/gjson"
 )
 
@@ -229,30 +232,6 @@ func (d *Database) StateEntries(
 	return d.StateBlockTable.BulkSelectStateBlockEntries(ctx, stateBlockNIDs)
 }
 
-func (d *Database) GetRoomVersionForRoom(
-	ctx context.Context, roomID string,
-) (gomatrixserverlib.RoomVersion, error) {
-	if roomVersion, ok := d.Cache.GetRoomVersion(roomID); ok {
-		return roomVersion, nil
-	}
-	return d.RoomsTable.SelectRoomVersionForRoomID(
-		ctx, nil, roomID,
-	)
-}
-
-func (d *Database) GetRoomVersionForRoomNID(
-	ctx context.Context, roomNID types.RoomNID,
-) (gomatrixserverlib.RoomVersion, error) {
-	if roomID, ok := d.Cache.GetRoomServerRoomID(roomNID); ok {
-		if roomVersion, ok := d.Cache.GetRoomVersion(roomID); ok {
-			return roomVersion, nil
-		}
-	}
-	return d.RoomsTable.SelectRoomVersionForRoomNID(
-		ctx, roomNID,
-	)
-}
-
 func (d *Database) SetRoomAlias(ctx context.Context, alias string, roomID string, creatorUserID string) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		return d.RoomAliasesTable.InsertRoomAlias(ctx, txn, alias, roomID, creatorUserID)
@@ -387,7 +366,7 @@ func (d *Database) MembershipUpdater(
 }
 
 func (d *Database) GetLatestEventsForUpdate(
-	ctx context.Context, roomNID types.RoomNID,
+	ctx context.Context, roomInfo types.RoomInfo,
 ) (*LatestEventsUpdater, error) {
 	txn, err := d.DB.Begin()
 	if err != nil {
@@ -395,7 +374,7 @@ func (d *Database) GetLatestEventsForUpdate(
 	}
 	var updater *LatestEventsUpdater
 	_ = d.Writer.Do(d.DB, txn, func(txn *sql.Tx) error {
-		updater, err = NewLatestEventsUpdater(ctx, d, txn, roomNID)
+		updater, err = NewLatestEventsUpdater(ctx, d, txn, roomInfo)
 		return nil
 	})
 	return updater, err
@@ -735,3 +714,190 @@ func (d *Database) loadEvent(ctx context.Context, eventID string) *types.Event {
 	}
 	return &evs[0]
 }
+
+// GetStateEvent returns the current state event of a given type for a given room with a given state key
+// If no event could be found, returns nil
+// If there was an issue during the retrieval, returns an error
+func (d *Database) GetStateEvent(ctx context.Context, roomID, evType, stateKey string) (*gomatrixserverlib.HeaderedEvent, error) {
+	roomInfo, err := d.RoomInfo(ctx, roomID)
+	if err != nil {
+		return nil, err
+	}
+	eventTypeNID, err := d.EventTypesTable.SelectEventTypeNID(ctx, nil, evType)
+	if err != nil {
+		return nil, err
+	}
+	stateKeyNID, err := d.EventStateKeysTable.SelectEventStateKeyNID(ctx, nil, stateKey)
+	if err != nil {
+		return nil, err
+	}
+	entries, err := d.loadStateAtSnapshot(ctx, roomInfo.StateSnapshotNID)
+	if err != nil {
+		return nil, err
+	}
+	// return the event requested
+	for _, e := range entries {
+		if e.EventTypeNID == eventTypeNID && e.EventStateKeyNID == stateKeyNID {
+			data, err := d.EventJSONTable.BulkSelectEventJSON(ctx, []types.EventNID{e.EventNID})
+			if err != nil {
+				return nil, err
+			}
+			if len(data) == 0 {
+				return nil, fmt.Errorf("GetStateEvent: no json for event nid %d", e.EventNID)
+			}
+			ev, err := gomatrixserverlib.NewEventFromTrustedJSON(data[0].EventJSON, false, roomInfo.RoomVersion)
+			if err != nil {
+				return nil, err
+			}
+			h := ev.Headered(roomInfo.RoomVersion)
+			return &h, nil
+		}
+	}
+
+	return nil, fmt.Errorf("GetStateEvent: no event type '%s' with key '%s' exists in room %s", evType, stateKey, roomID)
+}
+
+// GetRoomsByMembership returns a list of room IDs matching the provided membership and user ID (as state_key).
+func (d *Database) GetRoomsByMembership(ctx context.Context, userID, membership string) ([]string, error) {
+	var membershipState tables.MembershipState
+	switch membership {
+	case "join":
+		membershipState = tables.MembershipStateJoin
+	case "invite":
+		membershipState = tables.MembershipStateInvite
+	case "leave":
+		membershipState = tables.MembershipStateLeaveOrBan
+	case "ban":
+		membershipState = tables.MembershipStateLeaveOrBan
+	default:
+		return nil, fmt.Errorf("GetRoomsByMembership: invalid membership %s", membership)
+	}
+	stateKeyNID, err := d.EventStateKeysTable.SelectEventStateKeyNID(ctx, nil, userID)
+	if err != nil {
+		return nil, fmt.Errorf("GetRoomsByMembership: cannot map user ID to state key NID: %w", err)
+	}
+	roomNIDs, err := d.MembershipTable.SelectRoomsWithMembership(ctx, stateKeyNID, membershipState)
+	if err != nil {
+		return nil, err
+	}
+	roomIDs, err := d.RoomsTable.BulkSelectRoomIDs(ctx, roomNIDs)
+	if err != nil {
+		return nil, err
+	}
+	if len(roomIDs) != len(roomNIDs) {
+		return nil, fmt.Errorf("GetRoomsByMembership: missing room IDs, got %d want %d", len(roomIDs), len(roomNIDs))
+	}
+	return roomIDs, nil
+}
+
+// GetBulkStateContent returns all state events which match a given room ID and a given state key tuple. Both must be satisfied for a match.
+// If a tuple has the StateKey of '*' and allowWildcards=true then all state events with the EventType should be returned.
+func (d *Database) GetBulkStateContent(ctx context.Context, roomIDs []string, tuples []gomatrixserverlib.StateKeyTuple, allowWildcards bool) ([]csstables.StrippedEvent, error) {
+	return nil, fmt.Errorf("not implemented yet")
+}
+
+// JoinedUsersSetInRooms returns all joined users in the rooms given, along with the count of how many times they appear.
+func (d *Database) JoinedUsersSetInRooms(ctx context.Context, roomIDs []string) (map[string]int, error) {
+	roomNIDs, err := d.RoomsTable.BulkSelectRoomNIDs(ctx, roomIDs)
+	if err != nil {
+		return nil, err
+	}
+	userNIDToCount, err := d.MembershipTable.SelectJoinedUsersSetForRooms(ctx, roomNIDs)
+	if err != nil {
+		return nil, err
+	}
+	stateKeyNIDs := make([]types.EventStateKeyNID, len(userNIDToCount))
+	i := 0
+	for nid := range userNIDToCount {
+		stateKeyNIDs[i] = nid
+		i++
+	}
+	nidToUserID, err := d.EventStateKeysTable.BulkSelectEventStateKey(ctx, stateKeyNIDs)
+	if err != nil {
+		return nil, err
+	}
+	if len(nidToUserID) != len(userNIDToCount) {
+		return nil, fmt.Errorf("found %d users but only have state key nids for %d of them", len(userNIDToCount), len(nidToUserID))
+	}
+	result := make(map[string]int, len(userNIDToCount))
+	for nid, count := range userNIDToCount {
+		result[nidToUserID[nid]] = count
+	}
+	return result, nil
+}
+
+// GetKnownUsers searches all users that userID knows about.
+func (d *Database) GetKnownUsers(ctx context.Context, userID, searchString string, limit int) ([]string, error) {
+	stateKeyNID, err := d.EventStateKeysTable.SelectEventStateKeyNID(ctx, nil, userID)
+	if err != nil {
+		return nil, err
+	}
+	return d.MembershipTable.SelectKnownUsers(ctx, stateKeyNID, searchString, limit)
+}
+
+// GetKnownRooms returns a list of all rooms we know about.
+func (d *Database) GetKnownRooms(ctx context.Context) ([]string, error) {
+	return d.RoomsTable.SelectRoomIDs(ctx)
+}
+
+// FIXME TODO: Remove all this - horrible dupe with roomserver/state. Can't use the original impl because of circular loops
+// it should live in this package!
+
+func (d *Database) loadStateAtSnapshot(
+	ctx context.Context, stateNID types.StateSnapshotNID,
+) ([]types.StateEntry, error) {
+	stateBlockNIDLists, err := d.StateBlockNIDs(ctx, []types.StateSnapshotNID{stateNID})
+	if err != nil {
+		return nil, err
+	}
+	// We've asked for exactly one snapshot from the db so we should have exactly one entry in the result.
+	stateBlockNIDList := stateBlockNIDLists[0]
+
+	stateEntryLists, err := d.StateEntries(ctx, stateBlockNIDList.StateBlockNIDs)
+	if err != nil {
+		return nil, err
+	}
+	stateEntriesMap := stateEntryListMap(stateEntryLists)
+
+	// Combine all the state entries for this snapshot.
+	// The order of state block NIDs in the list tells us the order to combine them in.
+	var fullState []types.StateEntry
+	for _, stateBlockNID := range stateBlockNIDList.StateBlockNIDs {
+		entries, ok := stateEntriesMap.lookup(stateBlockNID)
+		if !ok {
+			// This should only get hit if the database is corrupt.
+			// It should be impossible for an event to reference a NID that doesn't exist
+			panic(fmt.Errorf("Corrupt DB: Missing state block numeric ID %d", stateBlockNID))
+		}
+		fullState = append(fullState, entries...)
+	}
+
+	// Stable sort so that the most recent entry for each state key stays
+	// remains later in the list than the older entries for the same state key.
+	sort.Stable(stateEntryByStateKeySorter(fullState))
+	// Unique returns the last entry and hence the most recent entry for each state key.
+	fullState = fullState[:util.Unique(stateEntryByStateKeySorter(fullState))]
+	return fullState, nil
+}
+
+type stateEntryListMap []types.StateEntryList
+
+func (m stateEntryListMap) lookup(stateBlockNID types.StateBlockNID) (stateEntries []types.StateEntry, ok bool) {
+	list := []types.StateEntryList(m)
+	i := sort.Search(len(list), func(i int) bool {
+		return list[i].StateBlockNID >= stateBlockNID
+	})
+	if i < len(list) && list[i].StateBlockNID == stateBlockNID {
+		ok = true
+		stateEntries = list[i].StateEntries
+	}
+	return
+}
+
+type stateEntryByStateKeySorter []types.StateEntry
+
+func (s stateEntryByStateKeySorter) Len() int { return len(s) }
+func (s stateEntryByStateKeySorter) Less(i, j int) bool {
+	return s[i].StateKeyTuple.LessThan(s[j].StateKeyTuple)
+}
+func (s stateEntryByStateKeySorter) Swap(i, j int) { s[i], s[j] = s[j], s[i] }

roomserver/storage/sqlite3/membership_table.go

@@ -18,6 +18,8 @@ package sqlite3
 import (
 	"context"
 	"database/sql"
+	"fmt"
+	"strings"
 
 	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
@@ -38,6 +40,10 @@ const membershipSchema = `
 	);
 `
 
+var selectJoinedUsersSetForRoomsSQL = "" +
+	"SELECT target_nid, COUNT(room_nid) FROM roomserver_membership WHERE room_nid = ANY($1) AND" +
+	" membership_nid = " + fmt.Sprintf("%d", tables.MembershipStateJoin) + " GROUP BY target_nid"
+
 // Insert a row in to membership table so that it can be locked by the
 // SELECT FOR UPDATE
 const insertMembershipSQL = "" +
@@ -75,6 +81,19 @@ const updateMembershipSQL = "" +
 	"UPDATE roomserver_membership SET sender_nid = $1, membership_nid = $2, event_nid = $3" +
 	" WHERE room_nid = $4 AND target_nid = $5"
 
+const selectRoomsWithMembershipSQL = "" +
+	"SELECT room_nid FROM roomserver_membership WHERE membership_nid = $1 AND target_nid = $2"
+
+// selectKnownUsersSQL uses a sub-select statement here to find rooms that the user is
+// joined to. Since this information is used to populate the user directory, we will
+// only return users that the user would ordinarily be able to see anyway.
+var selectKnownUsersSQL = "" +
+	"SELECT DISTINCT event_state_key FROM roomserver_membership INNER JOIN roomserver_event_state_keys ON " +
+	"roomserver_membership.target_nid = roomserver_event_state_keys.event_state_key_nid" +
+	" WHERE room_nid IN (" +
+	"  SELECT DISTINCT room_nid FROM roomserver_membership WHERE target_nid=$1 AND membership_nid = " + fmt.Sprintf("%d", tables.MembershipStateJoin) +
+	") AND membership_nid = " + fmt.Sprintf("%d", tables.MembershipStateJoin) + " AND event_state_key LIKE $2 LIMIT $3"
+
 type membershipStatements struct {
 	db                                              *sql.DB
 	insertMembershipStmt                            *sql.Stmt
@@ -84,7 +103,9 @@ type membershipStatements struct {
 	selectLocalMembershipsFromRoomAndMembershipStmt *sql.Stmt
 	selectMembershipsFromRoomStmt                   *sql.Stmt
 	selectLocalMembershipsFromRoomStmt              *sql.Stmt
+	selectRoomsWithMembershipStmt                   *sql.Stmt
 	updateMembershipStmt                            *sql.Stmt
+	selectKnownUsersStmt                            *sql.Stmt
 }
 
 func NewSqliteMembershipTable(db *sql.DB) (tables.Membership, error) {
@@ -105,6 +126,8 @@ func NewSqliteMembershipTable(db *sql.DB) (tables.Membership, error) {
 		{&s.selectMembershipsFromRoomStmt, selectMembershipsFromRoomSQL},
 		{&s.selectLocalMembershipsFromRoomStmt, selectLocalMembershipsFromRoomSQL},
 		{&s.updateMembershipStmt, updateMembershipSQL},
+		{&s.selectRoomsWithMembershipStmt, selectRoomsWithMembershipSQL},
+		{&s.selectKnownUsersStmt, selectKnownUsersSQL},
 	}.Prepare(db)
 }
 
@@ -203,3 +226,62 @@ func (s *membershipStatements) UpdateMembership(
 	)
 	return err
 }
+
+func (s *membershipStatements) SelectRoomsWithMembership(
+	ctx context.Context, userID types.EventStateKeyNID, membershipState tables.MembershipState,
+) ([]types.RoomNID, error) {
+	rows, err := s.selectRoomsWithMembershipStmt.QueryContext(ctx, membershipState, userID)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "SelectRoomsWithMembership: rows.close() failed")
+	var roomNIDs []types.RoomNID
+	for rows.Next() {
+		var roomNID types.RoomNID
+		if err := rows.Scan(&roomNID); err != nil {
+			return nil, err
+		}
+		roomNIDs = append(roomNIDs, roomNID)
+	}
+	return roomNIDs, nil
+}
+
+func (s *membershipStatements) SelectJoinedUsersSetForRooms(ctx context.Context, roomNIDs []types.RoomNID) (map[types.EventStateKeyNID]int, error) {
+	iRoomNIDs := make([]interface{}, len(roomNIDs))
+	for i, v := range roomNIDs {
+		iRoomNIDs[i] = v
+	}
+	query := strings.Replace(selectJoinedUsersSetForRoomsSQL, "($1)", sqlutil.QueryVariadic(len(iRoomNIDs)), 1)
+	rows, err := s.db.QueryContext(ctx, query, iRoomNIDs...)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectJoinedUsersSetForRooms: rows.close() failed")
+	result := make(map[types.EventStateKeyNID]int)
+	for rows.Next() {
+		var userID types.EventStateKeyNID
+		var count int
+		if err := rows.Scan(&userID, &count); err != nil {
+			return nil, err
+		}
+		result[userID] = count
+	}
+	return result, rows.Err()
+}
+
+func (s *membershipStatements) SelectKnownUsers(ctx context.Context, userID types.EventStateKeyNID, searchString string, limit int) ([]string, error) {
+	rows, err := s.selectKnownUsersStmt.QueryContext(ctx, userID, fmt.Sprintf("%%%s%%", searchString), limit)
+	if err != nil {
+		return nil, err
+	}
+	result := []string{}
+	defer internal.CloseAndLogIfError(ctx, rows, "SelectKnownUsers: rows.close() failed")
+	for rows.Next() {
+		var userID string
+		if err := rows.Scan(&userID); err != nil {
+			return nil, err
+		}
+		result = append(result, userID)
+	}
+	return result, rows.Err()
+}

roomserver/storage/sqlite3/rooms_table.go

@@ -21,7 +21,9 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"strings"
 
+	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/roomserver/storage/shared"
 	"github.com/matrix-org/dendrite/roomserver/storage/tables"
@@ -58,15 +60,21 @@ 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"
 
 const selectRoomInfoSQL = "" +
 	"SELECT room_version, room_nid, state_snapshot_nid, latest_event_nids FROM roomserver_rooms WHERE room_id = $1"
 
+const selectRoomIDsSQL = "" +
+	"SELECT room_id FROM roomserver_rooms"
+
+const bulkSelectRoomIDsSQL = "" +
+	"SELECT room_id FROM roomserver_rooms WHERE room_nid IN ($1)"
+
+const bulkSelectRoomNIDsSQL = "" +
+	"SELECT room_nid FROM roomserver_rooms WHERE room_id IN ($1)"
+
 type roomStatements struct {
 	db                                 *sql.DB
 	insertRoomNIDStmt                  *sql.Stmt
@@ -74,9 +82,9 @@ type roomStatements struct {
 	selectLatestEventNIDsStmt          *sql.Stmt
 	selectLatestEventNIDsForUpdateStmt *sql.Stmt
 	updateLatestEventNIDsStmt          *sql.Stmt
-	selectRoomVersionForRoomIDStmt     *sql.Stmt
 	selectRoomVersionForRoomNIDStmt    *sql.Stmt
 	selectRoomInfoStmt                 *sql.Stmt
+	selectRoomIDsStmt                  *sql.Stmt
 }
 
 func NewSqliteRoomsTable(db *sql.DB) (tables.Rooms, error) {
@@ -93,12 +101,29 @@ func NewSqliteRoomsTable(db *sql.DB) (tables.Rooms, error) {
 		{&s.selectLatestEventNIDsStmt, selectLatestEventNIDsSQL},
 		{&s.selectLatestEventNIDsForUpdateStmt, selectLatestEventNIDsForUpdateSQL},
 		{&s.updateLatestEventNIDsStmt, updateLatestEventNIDsSQL},
-		{&s.selectRoomVersionForRoomIDStmt, selectRoomVersionForRoomIDSQL},
 		{&s.selectRoomVersionForRoomNIDStmt, selectRoomVersionForRoomNIDSQL},
 		{&s.selectRoomInfoStmt, selectRoomInfoSQL},
+		{&s.selectRoomIDsStmt, selectRoomIDsSQL},
 	}.Prepare(db)
 }
 
+func (s *roomStatements) SelectRoomIDs(ctx context.Context) ([]string, error) {
+	rows, err := s.selectRoomIDsStmt.QueryContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectRoomIDsStmt: rows.close() failed")
+	var roomIDs []string
+	for rows.Next() {
+		var roomID string
+		if err = rows.Scan(&roomID); err != nil {
+			return nil, err
+		}
+		roomIDs = append(roomIDs, roomID)
+	}
+	return roomIDs, nil
+}
+
 func (s *roomStatements) SelectRoomInfo(ctx context.Context, roomID string) (*types.RoomInfo, error) {
 	var info types.RoomInfo
 	var latestNIDsJSON string
@@ -198,18 +223,6 @@ 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 := sqlutil.TxStmt(txn, s.selectRoomVersionForRoomIDStmt)
-	err := stmt.QueryRowContext(ctx, roomID).Scan(&roomVersion)
-	if err == sql.ErrNoRows {
-		return roomVersion, errors.New("room not found")
-	}
-	return roomVersion, err
-}
-
 func (s *roomStatements) SelectRoomVersionForRoomNID(
 	ctx context.Context, roomNID types.RoomNID,
 ) (gomatrixserverlib.RoomVersion, error) {
@@ -220,3 +233,47 @@ func (s *roomStatements) SelectRoomVersionForRoomNID(
 	}
 	return roomVersion, err
 }
+
+func (s *roomStatements) BulkSelectRoomIDs(ctx context.Context, roomNIDs []types.RoomNID) ([]string, error) {
+	iRoomNIDs := make([]interface{}, len(roomNIDs))
+	for i, v := range roomNIDs {
+		iRoomNIDs[i] = v
+	}
+	sqlQuery := strings.Replace(bulkSelectRoomIDsSQL, "($1)", sqlutil.QueryVariadic(len(roomNIDs)), 1)
+	rows, err := s.db.QueryContext(ctx, sqlQuery, iRoomNIDs...)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "bulkSelectRoomIDsStmt: rows.close() failed")
+	var roomIDs []string
+	for rows.Next() {
+		var roomID string
+		if err = rows.Scan(&roomID); err != nil {
+			return nil, err
+		}
+		roomIDs = append(roomIDs, roomID)
+	}
+	return roomIDs, nil
+}
+
+func (s *roomStatements) BulkSelectRoomNIDs(ctx context.Context, roomIDs []string) ([]types.RoomNID, error) {
+	iRoomIDs := make([]interface{}, len(roomIDs))
+	for i, v := range roomIDs {
+		iRoomIDs[i] = v
+	}
+	sqlQuery := strings.Replace(bulkSelectRoomNIDsSQL, "($1)", sqlutil.QueryVariadic(len(roomIDs)), 1)
+	rows, err := s.db.QueryContext(ctx, sqlQuery, iRoomIDs...)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "bulkSelectRoomNIDsStmt: rows.close() failed")
+	var roomNIDs []types.RoomNID
+	for rows.Next() {
+		var roomNID types.RoomNID
+		if err = rows.Scan(&roomNID); err != nil {
+			return nil, err
+		}
+		roomNIDs = append(roomNIDs, roomNID)
+	}
+	return roomNIDs, nil
+}

roomserver/storage/sqlite3/storage.go

@@ -150,7 +150,7 @@ func (d *Database) SupportsConcurrentRoomInputs() bool {
 }
 
 func (d *Database) GetLatestEventsForUpdate(
-	ctx context.Context, roomNID types.RoomNID,
+	ctx context.Context, roomInfo types.RoomInfo,
 ) (*shared.LatestEventsUpdater, error) {
 	// TODO: Do not use transactions. We should be holding open this transaction but we cannot have
 	// multiple write transactions on sqlite. The code will perform additional
@@ -158,7 +158,7 @@ func (d *Database) GetLatestEventsForUpdate(
 	// 'database is locked' errors. As sqlite doesn't support multi-process on the
 	// same DB anyway, and we only execute updates sequentially, the only worries
 	// are for rolling back when things go wrong. (atomicity)
-	return shared.NewLatestEventsUpdater(ctx, &d.Database, nil, roomNID)
+	return shared.NewLatestEventsUpdater(ctx, &d.Database, nil, roomInfo)
 }
 
 func (d *Database) MembershipUpdater(

roomserver/storage/tables/interface.go

@@ -63,9 +63,11 @@ type Rooms interface {
 	SelectLatestEventNIDs(ctx context.Context, txn *sql.Tx, roomNID types.RoomNID) ([]types.EventNID, types.StateSnapshotNID, error)
 	SelectLatestEventsNIDsForUpdate(ctx context.Context, txn *sql.Tx, roomNID types.RoomNID) ([]types.EventNID, types.EventNID, types.StateSnapshotNID, error)
 	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)
+	SelectRoomIDs(ctx context.Context) ([]string, error)
+	BulkSelectRoomIDs(ctx context.Context, roomNIDs []types.RoomNID) ([]string, error)
+	BulkSelectRoomNIDs(ctx context.Context, roomIDs []string) ([]types.RoomNID, error)
 }
 
 type Transactions interface {
@@ -121,6 +123,11 @@ type Membership interface {
 	SelectMembershipsFromRoom(ctx context.Context, roomNID types.RoomNID, localOnly bool) (eventNIDs []types.EventNID, err error)
 	SelectMembershipsFromRoomAndMembership(ctx context.Context, roomNID types.RoomNID, membership MembershipState, localOnly bool) (eventNIDs []types.EventNID, err error)
 	UpdateMembership(ctx context.Context, txn *sql.Tx, roomNID types.RoomNID, targetUserNID types.EventStateKeyNID, senderUserNID types.EventStateKeyNID, membership MembershipState, eventNID types.EventNID) error
+	SelectRoomsWithMembership(ctx context.Context, userID types.EventStateKeyNID, membershipState MembershipState) ([]types.RoomNID, error)
+	// SelectJoinedUsersSetForRooms returns the set of all users in the rooms who are joined to any of these rooms, along with the
+	// counts of how many rooms they are joined.
+	SelectJoinedUsersSetForRooms(ctx context.Context, roomNIDs []types.RoomNID) (map[types.EventStateKeyNID]int, error)
+	SelectKnownUsers(ctx context.Context, userID types.EventStateKeyNID, searchString string, limit int) ([]string, error)
 }
 
 type Published interface {