19 files changed, 628 insertions, 3 deletions
diff --git a/roomserver/api/api.go b/roomserver/api/api.go
index 420ef278..a8228ae8 100644
--- a/roomserver/api/api.go
+++ b/roomserver/api/api.go
@@ -151,6 +151,7 @@ type ClientRoomserverAPI interface {
 	PerformRoomUpgrade(ctx context.Context, req *PerformRoomUpgradeRequest, resp *PerformRoomUpgradeResponse) error
 	PerformAdminEvacuateRoom(ctx context.Context, req *PerformAdminEvacuateRoomRequest, res *PerformAdminEvacuateRoomResponse) error
 	PerformAdminEvacuateUser(ctx context.Context, req *PerformAdminEvacuateUserRequest, res *PerformAdminEvacuateUserResponse) error
+	PerformAdminPurgeRoom(ctx context.Context, req *PerformAdminPurgeRoomRequest, res *PerformAdminPurgeRoomResponse) error
 	PerformAdminDownloadState(ctx context.Context, req *PerformAdminDownloadStateRequest, res *PerformAdminDownloadStateResponse) error
 	PerformPeek(ctx context.Context, req *PerformPeekRequest, res *PerformPeekResponse) error
 	PerformUnpeek(ctx context.Context, req *PerformUnpeekRequest, res *PerformUnpeekResponse) error
diff --git a/roomserver/api/api_trace.go b/roomserver/api/api_trace.go
index b23263d1..166b651a 100644
--- a/roomserver/api/api_trace.go
+++ b/roomserver/api/api_trace.go
@@ -137,6 +137,16 @@ func (t *RoomserverInternalAPITrace) PerformAdminEvacuateUser(
 	return err
 }
 
+func (t *RoomserverInternalAPITrace) PerformAdminPurgeRoom(
+	ctx context.Context,
+	req *PerformAdminPurgeRoomRequest,
+	res *PerformAdminPurgeRoomResponse,
+) error {
+	err := t.Impl.PerformAdminPurgeRoom(ctx, req, res)
+	util.GetLogger(ctx).WithError(err).Infof("PerformAdminPurgeRoom req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
 func (t *RoomserverInternalAPITrace) PerformAdminDownloadState(
 	ctx context.Context,
 	req *PerformAdminDownloadStateRequest,
diff --git a/roomserver/api/output.go b/roomserver/api/output.go
index 36d0625c..0c0f52c4 100644
--- a/roomserver/api/output.go
+++ b/roomserver/api/output.go
@@ -55,6 +55,8 @@ const (
 	OutputTypeNewInboundPeek OutputType = "new_inbound_peek"
 	// OutputTypeRetirePeek indicates that the kafka event is an OutputRetirePeek
 	OutputTypeRetirePeek OutputType = "retire_peek"
+	// OutputTypePurgeRoom indicates the event is an OutputPurgeRoom
+	OutputTypePurgeRoom OutputType = "purge_room"
 )
 
 // An OutputEvent is an entry in the roomserver output kafka log.
@@ -78,6 +80,8 @@ type OutputEvent struct {
 	NewInboundPeek *OutputNewInboundPeek `json:"new_inbound_peek,omitempty"`
 	// The content of event with type OutputTypeRetirePeek
 	RetirePeek *OutputRetirePeek `json:"retire_peek,omitempty"`
+	// The content of the event with type OutputPurgeRoom
+	PurgeRoom *OutputPurgeRoom `json:"purge_room,omitempty"`
 }
 
 // Type of the OutputNewRoomEvent.
@@ -257,3 +261,7 @@ type OutputRetirePeek struct {
 	UserID   string
 	DeviceID string
 }
+
+type OutputPurgeRoom struct {
+	RoomID string
+}
diff --git a/roomserver/api/perform.go b/roomserver/api/perform.go
index e789b956..83cb0460 100644
--- a/roomserver/api/perform.go
+++ b/roomserver/api/perform.go
@@ -241,6 +241,14 @@ type PerformAdminEvacuateUserResponse struct {
 	Error    *PerformError
 }
 
+type PerformAdminPurgeRoomRequest struct {
+	RoomID string `json:"room_id"`
+}
+
+type PerformAdminPurgeRoomResponse struct {
+	Error *PerformError `json:"error,omitempty"`
+}
+
 type PerformAdminDownloadStateRequest struct {
 	RoomID     string                       `json:"room_id"`
 	UserID     string                       `json:"user_id"`
diff --git a/roomserver/internal/perform/perform_admin.go b/roomserver/internal/perform/perform_admin.go
index d42f4e45..3256162b 100644
--- a/roomserver/internal/perform/perform_admin.go
+++ b/roomserver/internal/perform/perform_admin.go
@@ -28,6 +28,7 @@ import (
 	"github.com/matrix-org/dendrite/roomserver/storage"
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
 )
 
 type Admin struct {
@@ -242,6 +243,42 @@ func (r *Admin) PerformAdminEvacuateUser(
 	return nil
 }
 
+func (r *Admin) PerformAdminPurgeRoom(
+	ctx context.Context,
+	req *api.PerformAdminPurgeRoomRequest,
+	res *api.PerformAdminPurgeRoomResponse,
+) error {
+	// Validate we actually got a room ID and nothing else
+	if _, _, err := gomatrixserverlib.SplitID('!', req.RoomID); err != nil {
+		res.Error = &api.PerformError{
+			Code: api.PerformErrorBadRequest,
+			Msg:  fmt.Sprintf("Malformed room ID: %s", err),
+		}
+		return nil
+	}
+
+	logrus.WithField("room_id", req.RoomID).Warn("Purging room from roomserver")
+	if err := r.DB.PurgeRoom(ctx, req.RoomID); err != nil {
+		logrus.WithField("room_id", req.RoomID).WithError(err).Warn("Failed to purge room from roomserver")
+		res.Error = &api.PerformError{
+			Code: api.PerformErrorBadRequest,
+			Msg:  err.Error(),
+		}
+		return nil
+	}
+
+	logrus.WithField("room_id", req.RoomID).Warn("Room purged from roomserver")
+
+	return r.Inputer.OutputProducer.ProduceRoomEvents(req.RoomID, []api.OutputEvent{
+		{
+			Type: api.OutputTypePurgeRoom,
+			PurgeRoom: &api.OutputPurgeRoom{
+				RoomID: req.RoomID,
+			},
+		},
+	})
+}
+
 func (r *Admin) PerformAdminDownloadState(
 	ctx context.Context,
 	req *api.PerformAdminDownloadStateRequest,
diff --git a/roomserver/inthttp/client.go b/roomserver/inthttp/client.go
index 8a2e0a03..556a137b 100644
--- a/roomserver/inthttp/client.go
+++ b/roomserver/inthttp/client.go
@@ -40,6 +40,7 @@ const (
 	RoomserverPerformAdminEvacuateRoomPath  = "/roomserver/performAdminEvacuateRoom"
 	RoomserverPerformAdminEvacuateUserPath  = "/roomserver/performAdminEvacuateUser"
 	RoomserverPerformAdminDownloadStatePath = "/roomserver/performAdminDownloadState"
+	RoomserverPerformAdminPurgeRoomPath     = "/roomserver/performAdminPurgeRoom"
 
 	// Query operations
 	RoomserverQueryLatestEventsAndStatePath    = "/roomserver/queryLatestEventsAndState"
@@ -285,6 +286,17 @@ func (h *httpRoomserverInternalAPI) PerformAdminEvacuateUser(
 	)
 }
 
+func (h *httpRoomserverInternalAPI) PerformAdminPurgeRoom(
+	ctx context.Context,
+	request *api.PerformAdminPurgeRoomRequest,
+	response *api.PerformAdminPurgeRoomResponse,
+) error {
+	return httputil.CallInternalRPCAPI(
+		"PerformAdminPurgeRoom", h.roomserverURL+RoomserverPerformAdminPurgeRoomPath,
+		h.httpClient, ctx, request, response,
+	)
+}
+
 // QueryLatestEventsAndState implements RoomserverQueryAPI
 func (h *httpRoomserverInternalAPI) QueryLatestEventsAndState(
 	ctx context.Context,
diff --git a/roomserver/inthttp/server.go b/roomserver/inthttp/server.go
index 4d21909b..f3a51b0b 100644
--- a/roomserver/inthttp/server.go
+++ b/roomserver/inthttp/server.go
@@ -66,6 +66,11 @@ func AddRoutes(r api.RoomserverInternalAPI, internalAPIMux *mux.Router, enableMe
 	)
 
 	internalAPIMux.Handle(
+		RoomserverPerformAdminPurgeRoomPath,
+		httputil.MakeInternalRPCAPI("RoomserverPerformAdminPurgeRoom", enableMetrics, r.PerformAdminPurgeRoom),
+	)
+
+	internalAPIMux.Handle(
 		RoomserverPerformAdminDownloadStatePath,
 		httputil.MakeInternalRPCAPI("RoomserverPerformAdminDownloadState", enableMetrics, r.PerformAdminDownloadState),
 	)
diff --git a/roomserver/roomserver_test.go b/roomserver/roomserver_test.go
index 595ceb52..3ec2560d 100644
--- a/roomserver/roomserver_test.go
+++ b/roomserver/roomserver_test.go
@@ -14,6 +14,10 @@ import (
 
 	userAPI "github.com/matrix-org/dendrite/userapi/api"
 
+	"github.com/matrix-org/dendrite/federationapi"
+	"github.com/matrix-org/dendrite/keyserver"
+	"github.com/matrix-org/dendrite/setup/jetstream"
+	"github.com/matrix-org/dendrite/syncapi"
 	"github.com/matrix-org/gomatrixserverlib"
 
 	"github.com/matrix-org/dendrite/roomserver"
@@ -223,3 +227,164 @@ func Test_QueryLeftUsers(t *testing.T) {
 
 	})
 }
+
+func TestPurgeRoom(t *testing.T) {
+	alice := test.NewUser(t)
+	bob := test.NewUser(t)
+	room := test.NewRoom(t, alice, test.RoomPreset(test.PresetTrustedPrivateChat))
+
+	// Invite Bob
+	inviteEvent := room.CreateAndInsert(t, alice, gomatrixserverlib.MRoomMember, map[string]interface{}{
+		"membership": "invite",
+	}, test.WithStateKey(bob.ID))
+
+	ctx := context.Background()
+
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		base, db, close := mustCreateDatabase(t, dbType)
+		defer close()
+
+		jsCtx, _ := base.NATS.Prepare(base.ProcessContext, &base.Cfg.Global.JetStream)
+		defer jetstream.DeleteAllStreams(jsCtx, &base.Cfg.Global.JetStream)
+
+		fedClient := base.CreateFederationClient()
+		rsAPI := roomserver.NewInternalAPI(base)
+		keyAPI := keyserver.NewInternalAPI(base, &base.Cfg.KeyServer, fedClient, rsAPI)
+		userAPI := userapi.NewInternalAPI(base, &base.Cfg.UserAPI, nil, keyAPI, rsAPI, nil)
+
+		// this starts the JetStream consumers
+		syncapi.AddPublicRoutes(base, userAPI, rsAPI, keyAPI)
+		federationapi.NewInternalAPI(base, fedClient, rsAPI, base.Caches, nil, true)
+		rsAPI.SetFederationAPI(nil, nil)
+
+		// Create the room
+		if err := api.SendEvents(ctx, rsAPI, api.KindNew, room.Events(), "test", "test", "test", nil, false); err != nil {
+			t.Fatalf("failed to send events: %v", err)
+		}
+
+		// some dummy entries to validate after purging
+		publishResp := &api.PerformPublishResponse{}
+		if err := rsAPI.PerformPublish(ctx, &api.PerformPublishRequest{RoomID: room.ID, Visibility: "public"}, publishResp); err != nil {
+			t.Fatal(err)
+		}
+		if publishResp.Error != nil {
+			t.Fatal(publishResp.Error)
+		}
+
+		isPublished, err := db.GetPublishedRoom(ctx, room.ID)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !isPublished {
+			t.Fatalf("room should be published before purging")
+		}
+
+		aliasResp := &api.SetRoomAliasResponse{}
+		if err = rsAPI.SetRoomAlias(ctx, &api.SetRoomAliasRequest{RoomID: room.ID, Alias: "myalias", UserID: alice.ID}, aliasResp); err != nil {
+			t.Fatal(err)
+		}
+		// check the alias is actually there
+		aliasesResp := &api.GetAliasesForRoomIDResponse{}
+		if err = rsAPI.GetAliasesForRoomID(ctx, &api.GetAliasesForRoomIDRequest{RoomID: room.ID}, aliasesResp); err != nil {
+			t.Fatal(err)
+		}
+		wantAliases := 1
+		if gotAliases := len(aliasesResp.Aliases); gotAliases != wantAliases {
+			t.Fatalf("expected %d aliases, got %d", wantAliases, gotAliases)
+		}
+
+		// validate the room exists before purging
+		roomInfo, err := db.RoomInfo(ctx, room.ID)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if roomInfo == nil {
+			t.Fatalf("room does not exist")
+		}
+		// remember the roomInfo before purging
+		existingRoomInfo := roomInfo
+
+		// validate there is an invite for bob
+		nids, err := db.EventStateKeyNIDs(ctx, []string{bob.ID})
+		if err != nil {
+			t.Fatal(err)
+		}
+		bobNID, ok := nids[bob.ID]
+		if !ok {
+			t.Fatalf("%s does not exist", bob.ID)
+		}
+
+		_, inviteEventIDs, _, err := db.GetInvitesForUser(ctx, roomInfo.RoomNID, bobNID)
+		if err != nil {
+			t.Fatal(err)
+		}
+		wantInviteCount := 1
+		if inviteCount := len(inviteEventIDs); inviteCount != wantInviteCount {
+			t.Fatalf("expected there to be only %d invite events, got %d", wantInviteCount, inviteCount)
+		}
+		if inviteEventIDs[0] != inviteEvent.EventID() {
+			t.Fatalf("expected invite event ID %s, got %s", inviteEvent.EventID(), inviteEventIDs[0])
+		}
+
+		// purge the room from the database
+		purgeResp := &api.PerformAdminPurgeRoomResponse{}
+		if err = rsAPI.PerformAdminPurgeRoom(ctx, &api.PerformAdminPurgeRoomRequest{RoomID: room.ID}, purgeResp); err != nil {
+			t.Fatal(err)
+		}
+
+		// wait for all consumers to process the purge event
+		var sum = 1
+		timeout := time.Second * 5
+		deadline, cancel := context.WithTimeout(context.Background(), timeout)
+		defer cancel()
+		for sum > 0 {
+			if deadline.Err() != nil {
+				t.Fatalf("test timed out after %s", timeout)
+			}
+			sum = 0
+			consumerCh := jsCtx.Consumers(base.Cfg.Global.JetStream.Prefixed(jetstream.OutputRoomEvent))
+			for x := range consumerCh {
+				sum += x.NumAckPending
+			}
+			time.Sleep(time.Millisecond)
+		}
+
+		roomInfo, err = db.RoomInfo(ctx, room.ID)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if roomInfo != nil {
+			t.Fatalf("room should not exist after purging: %+v", roomInfo)
+		}
+
+		// validation below
+
+		// There should be no invite left
+		_, inviteEventIDs, _, err = db.GetInvitesForUser(ctx, existingRoomInfo.RoomNID, bobNID)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if inviteCount := len(inviteEventIDs); inviteCount > 0 {
+			t.Fatalf("expected there to be only %d invite events, got %d", wantInviteCount, inviteCount)
+		}
+
+		// aliases should be deleted
+		aliases, err := db.GetAliasesForRoomID(ctx, room.ID)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if aliasCount := len(aliases); aliasCount > 0 {
+			t.Fatalf("expected there to be only %d invite events, got %d", 0, aliasCount)
+		}
+
+		// published room should be deleted
+		isPublished, err = db.GetPublishedRoom(ctx, room.ID)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if isPublished {
+			t.Fatalf("room should not be published after purging")
+		}
+	})
+}
diff --git a/roomserver/storage/interface.go b/roomserver/storage/interface.go
index 92bc2e66..e0b9c56b 100644
--- a/roomserver/storage/interface.go
+++ b/roomserver/storage/interface.go
@@ -173,5 +173,6 @@ type Database interface {
 
 	GetHistoryVisibilityState(ctx context.Context, roomInfo *types.RoomInfo, eventID string, domain string) ([]*gomatrixserverlib.Event, error)
 	GetLeftUsers(ctx context.Context, userIDs []string) ([]string, error)
+	PurgeRoom(ctx context.Context, roomID string) error
 	UpgradeRoom(ctx context.Context, oldRoomID, newRoomID, eventSender string) error
 }
diff --git a/roomserver/storage/postgres/purge_statements.go b/roomserver/storage/postgres/purge_statements.go
new file mode 100644
index 00000000..efba439b
--- /dev/null
+++ b/roomserver/storage/postgres/purge_statements.go
@@ -0,0 +1,133 @@
+// Copyright 2022 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 postgres
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/roomserver/types"
+)
+
+const purgeEventJSONSQL = "" +
+	"DELETE FROM roomserver_event_json WHERE event_nid = ANY(" +
+	"	SELECT event_nid FROM roomserver_events WHERE room_nid = $1" +
+	")"
+
+const purgeEventsSQL = "" +
+	"DELETE FROM roomserver_events WHERE room_nid = $1"
+
+const purgeInvitesSQL = "" +
+	"DELETE FROM roomserver_invites WHERE room_nid = $1"
+
+const purgeMembershipsSQL = "" +
+	"DELETE FROM roomserver_membership WHERE room_nid = $1"
+
+const purgePreviousEventsSQL = "" +
+	"DELETE FROM roomserver_previous_events WHERE event_nids && ANY(" +
+	"	SELECT ARRAY_AGG(event_nid) FROM roomserver_events WHERE room_nid = $1" +
+	")"
+
+const purgePublishedSQL = "" +
+	"DELETE FROM roomserver_published WHERE room_id = $1"
+
+const purgeRedactionsSQL = "" +
+	"DELETE FROM roomserver_redactions WHERE redaction_event_id = ANY(" +
+	"	SELECT event_id FROM roomserver_events WHERE room_nid = $1" +
+	")"
+
+const purgeRoomAliasesSQL = "" +
+	"DELETE FROM roomserver_room_aliases WHERE room_id = $1"
+
+const purgeRoomSQL = "" +
+	"DELETE FROM roomserver_rooms WHERE room_nid = $1"
+
+const purgeStateBlockEntriesSQL = "" +
+	"DELETE FROM roomserver_state_block WHERE state_block_nid = ANY(" +
+	"	SELECT DISTINCT UNNEST(state_block_nids) FROM roomserver_state_snapshots WHERE room_nid = $1" +
+	")"
+
+const purgeStateSnapshotEntriesSQL = "" +
+	"DELETE FROM roomserver_state_snapshots WHERE room_nid = $1"
+
+type purgeStatements struct {
+	purgeEventJSONStmt            *sql.Stmt
+	purgeEventsStmt               *sql.Stmt
+	purgeInvitesStmt              *sql.Stmt
+	purgeMembershipsStmt          *sql.Stmt
+	purgePreviousEventsStmt       *sql.Stmt
+	purgePublishedStmt            *sql.Stmt
+	purgeRedactionStmt            *sql.Stmt
+	purgeRoomAliasesStmt          *sql.Stmt
+	purgeRoomStmt                 *sql.Stmt
+	purgeStateBlockEntriesStmt    *sql.Stmt
+	purgeStateSnapshotEntriesStmt *sql.Stmt
+}
+
+func PreparePurgeStatements(db *sql.DB) (*purgeStatements, error) {
+	s := &purgeStatements{}
+
+	return s, sqlutil.StatementList{
+		{&s.purgeEventJSONStmt, purgeEventJSONSQL},
+		{&s.purgeEventsStmt, purgeEventsSQL},
+		{&s.purgeInvitesStmt, purgeInvitesSQL},
+		{&s.purgeMembershipsStmt, purgeMembershipsSQL},
+		{&s.purgePublishedStmt, purgePublishedSQL},
+		{&s.purgePreviousEventsStmt, purgePreviousEventsSQL},
+		{&s.purgeRedactionStmt, purgeRedactionsSQL},
+		{&s.purgeRoomAliasesStmt, purgeRoomAliasesSQL},
+		{&s.purgeRoomStmt, purgeRoomSQL},
+		{&s.purgeStateBlockEntriesStmt, purgeStateBlockEntriesSQL},
+		{&s.purgeStateSnapshotEntriesStmt, purgeStateSnapshotEntriesSQL},
+	}.Prepare(db)
+}
+
+func (s *purgeStatements) PurgeRoom(
+	ctx context.Context, txn *sql.Tx, roomNID types.RoomNID, roomID string,
+) error {
+
+	// purge by roomID
+	purgeByRoomID := []*sql.Stmt{
+		s.purgeRoomAliasesStmt,
+		s.purgePublishedStmt,
+	}
+	for _, stmt := range purgeByRoomID {
+		_, err := sqlutil.TxStmt(txn, stmt).ExecContext(ctx, roomID)
+		if err != nil {
+			return err
+		}
+	}
+
+	// purge by roomNID
+	purgeByRoomNID := []*sql.Stmt{
+		s.purgeStateBlockEntriesStmt,
+		s.purgeStateSnapshotEntriesStmt,
+		s.purgeInvitesStmt,
+		s.purgeMembershipsStmt,
+		s.purgePreviousEventsStmt,
+		s.purgeEventJSONStmt,
+		s.purgeRedactionStmt,
+		s.purgeEventsStmt,
+		s.purgeRoomStmt,
+	}
+	for _, stmt := range purgeByRoomNID {
+		_, err := sqlutil.TxStmt(txn, stmt).ExecContext(ctx, roomNID)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/roomserver/storage/postgres/rooms_table.go b/roomserver/storage/postgres/rooms_table.go
index 99439953..c8346733 100644
--- a/roomserver/storage/postgres/rooms_table.go
+++ b/roomserver/storage/postgres/rooms_table.go
@@ -58,6 +58,9 @@ const insertRoomNIDSQL = "" +
 const selectRoomNIDSQL = "" +
 	"SELECT room_nid FROM roomserver_rooms WHERE room_id = $1"
 
+const selectRoomNIDForUpdateSQL = "" +
+	"SELECT room_nid FROM roomserver_rooms WHERE room_id = $1 FOR UPDATE"
+
 const selectLatestEventNIDsSQL = "" +
 	"SELECT latest_event_nids, state_snapshot_nid FROM roomserver_rooms WHERE room_nid = $1"
 
@@ -85,6 +88,7 @@ const bulkSelectRoomNIDsSQL = "" +
 type roomStatements struct {
 	insertRoomNIDStmt                  *sql.Stmt
 	selectRoomNIDStmt                  *sql.Stmt
+	selectRoomNIDForUpdateStmt         *sql.Stmt
 	selectLatestEventNIDsStmt          *sql.Stmt
 	selectLatestEventNIDsForUpdateStmt *sql.Stmt
 	updateLatestEventNIDsStmt          *sql.Stmt
@@ -106,6 +110,7 @@ func PrepareRoomsTable(db *sql.DB) (tables.Rooms, error) {
 	return s, sqlutil.StatementList{
 		{&s.insertRoomNIDStmt, insertRoomNIDSQL},
 		{&s.selectRoomNIDStmt, selectRoomNIDSQL},
+		{&s.selectRoomNIDForUpdateStmt, selectRoomNIDForUpdateSQL},
 		{&s.selectLatestEventNIDsStmt, selectLatestEventNIDsSQL},
 		{&s.selectLatestEventNIDsForUpdateStmt, selectLatestEventNIDsForUpdateSQL},
 		{&s.updateLatestEventNIDsStmt, updateLatestEventNIDsSQL},
@@ -169,6 +174,15 @@ func (s *roomStatements) SelectRoomNID(
 	return types.RoomNID(roomNID), err
 }
 
+func (s *roomStatements) SelectRoomNIDForUpdate(
+	ctx context.Context, txn *sql.Tx, roomID string,
+) (types.RoomNID, error) {
+	var roomNID int64
+	stmt := sqlutil.TxStmt(txn, s.selectRoomNIDForUpdateStmt)
+	err := stmt.QueryRowContext(ctx, roomID).Scan(&roomNID)
+	return types.RoomNID(roomNID), err
+}
+
 func (s *roomStatements) SelectLatestEventNIDs(
 	ctx context.Context, txn *sql.Tx, roomNID types.RoomNID,
 ) ([]types.EventNID, types.StateSnapshotNID, error) {
diff --git a/roomserver/storage/postgres/storage.go b/roomserver/storage/postgres/storage.go
index 23a5f79e..87208438 100644
--- a/roomserver/storage/postgres/storage.go
+++ b/roomserver/storage/postgres/storage.go
@@ -189,6 +189,10 @@ func (d *Database) prepare(db *sql.DB, writer sqlutil.Writer, cache caching.Room
 	if err != nil {
 		return err
 	}
+	purge, err := PreparePurgeStatements(db)
+	if err != nil {
+		return err
+	}
 	d.Database = shared.Database{
 		DB:                  db,
 		Cache:               cache,
@@ -206,6 +210,7 @@ func (d *Database) prepare(db *sql.DB, writer sqlutil.Writer, cache caching.Room
 		MembershipTable:     membership,
 		PublishedTable:      published,
 		RedactionsTable:     redactions,
+		Purge:               purge,
 	}
 	return nil
 }
diff --git a/roomserver/storage/shared/storage.go b/roomserver/storage/shared/storage.go
index 725cc5bc..654b078d 100644
--- a/roomserver/storage/shared/storage.go
+++ b/roomserver/storage/shared/storage.go
@@ -43,6 +43,7 @@ type Database struct {
 	MembershipTable     tables.Membership
 	PublishedTable      tables.Published
 	RedactionsTable     tables.Redactions
+	Purge               tables.Purge
 	GetRoomUpdaterFn    func(ctx context.Context, roomInfo *types.RoomInfo) (*RoomUpdater, error)
 }
 
@@ -1445,6 +1446,21 @@ func (d *Database) ForgetRoom(ctx context.Context, userID, roomID string, forget
 	})
 }
 
+// PurgeRoom removes all information about a given room from the roomserver.
+// For large rooms this operation may take a considerable amount of time.
+func (d *Database) PurgeRoom(ctx context.Context, roomID string) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		roomNID, err := d.RoomsTable.SelectRoomNIDForUpdate(ctx, txn, roomID)
+		if err != nil {
+			if err == sql.ErrNoRows {
+				return fmt.Errorf("room %s does not exist", roomID)
+			}
+			return fmt.Errorf("failed to lock the room: %w", err)
+		}
+		return d.Purge.PurgeRoom(ctx, txn, roomNID, roomID)
+	})
+}
+
 func (d *Database) UpgradeRoom(ctx context.Context, oldRoomID, newRoomID, eventSender string) error {
 
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
diff --git a/roomserver/storage/sqlite3/purge_statements.go b/roomserver/storage/sqlite3/purge_statements.go
new file mode 100644
index 00000000..c7b4d27a
--- /dev/null
+++ b/roomserver/storage/sqlite3/purge_statements.go
@@ -0,0 +1,153 @@
+// Copyright 2022 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 sqlite3
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/roomserver/types"
+)
+
+const purgeEventJSONSQL = "" +
+	"DELETE FROM roomserver_event_json WHERE event_nid IN (" +
+	"	SELECT event_nid FROM roomserver_events WHERE room_nid = $1" +
+	")"
+
+const purgeEventsSQL = "" +
+	"DELETE FROM roomserver_events WHERE room_nid = $1"
+
+const purgeInvitesSQL = "" +
+	"DELETE FROM roomserver_invites WHERE room_nid = $1"
+
+const purgeMembershipsSQL = "" +
+	"DELETE FROM roomserver_membership WHERE room_nid = $1"
+
+const purgePreviousEventsSQL = "" +
+	"DELETE FROM roomserver_previous_events WHERE event_nids IN(" +
+	"	SELECT event_nid FROM roomserver_events WHERE room_nid = $1" +
+	")"
+
+const purgePublishedSQL = "" +
+	"DELETE FROM roomserver_published WHERE room_id = $1"
+
+const purgeRedactionsSQL = "" +
+	"DELETE FROM roomserver_redactions WHERE redaction_event_id IN(" +
+	"	SELECT event_id FROM roomserver_events WHERE room_nid = $1" +
+	")"
+
+const purgeRoomAliasesSQL = "" +
+	"DELETE FROM roomserver_room_aliases WHERE room_id = $1"
+
+const purgeRoomSQL = "" +
+	"DELETE FROM roomserver_rooms WHERE room_nid = $1"
+
+const purgeStateSnapshotEntriesSQL = "" +
+	"DELETE FROM roomserver_state_snapshots WHERE room_nid = $1"
+
+type purgeStatements struct {
+	purgeEventJSONStmt            *sql.Stmt
+	purgeEventsStmt               *sql.Stmt
+	purgeInvitesStmt              *sql.Stmt
+	purgeMembershipsStmt          *sql.Stmt
+	purgePreviousEventsStmt       *sql.Stmt
+	purgePublishedStmt            *sql.Stmt
+	purgeRedactionStmt            *sql.Stmt
+	purgeRoomAliasesStmt          *sql.Stmt
+	purgeRoomStmt                 *sql.Stmt
+	purgeStateSnapshotEntriesStmt *sql.Stmt
+	stateSnapshot                 *stateSnapshotStatements
+}
+
+func PreparePurgeStatements(db *sql.DB, stateSnapshot *stateSnapshotStatements) (*purgeStatements, error) {
+	s := &purgeStatements{stateSnapshot: stateSnapshot}
+	return s, sqlutil.StatementList{
+		{&s.purgeEventJSONStmt, purgeEventJSONSQL},
+		{&s.purgeEventsStmt, purgeEventsSQL},
+		{&s.purgeInvitesStmt, purgeInvitesSQL},
+		{&s.purgeMembershipsStmt, purgeMembershipsSQL},
+		{&s.purgePublishedStmt, purgePublishedSQL},
+		{&s.purgePreviousEventsStmt, purgePreviousEventsSQL},
+		{&s.purgeRedactionStmt, purgeRedactionsSQL},
+		{&s.purgeRoomAliasesStmt, purgeRoomAliasesSQL},
+		{&s.purgeRoomStmt, purgeRoomSQL},
+		//{&s.purgeStateBlockEntriesStmt, purgeStateBlockEntriesSQL},
+		{&s.purgeStateSnapshotEntriesStmt, purgeStateSnapshotEntriesSQL},
+	}.Prepare(db)
+}
+
+func (s *purgeStatements) PurgeRoom(
+	ctx context.Context, txn *sql.Tx, roomNID types.RoomNID, roomID string,
+) error {
+
+	// purge by roomID
+	purgeByRoomID := []*sql.Stmt{
+		s.purgeRoomAliasesStmt,
+		s.purgePublishedStmt,
+	}
+	for _, stmt := range purgeByRoomID {
+		_, err := sqlutil.TxStmt(txn, stmt).ExecContext(ctx, roomID)
+		if err != nil {
+			return err
+		}
+	}
+
+	// purge by roomNID
+	if err := s.purgeStateBlocks(ctx, txn, roomNID); err != nil {
+		return err
+	}
+
+	purgeByRoomNID := []*sql.Stmt{
+		s.purgeStateSnapshotEntriesStmt,
+		s.purgeInvitesStmt,
+		s.purgeMembershipsStmt,
+		s.purgePreviousEventsStmt,
+		s.purgeEventJSONStmt,
+		s.purgeRedactionStmt,
+		s.purgeEventsStmt,
+		s.purgeRoomStmt,
+	}
+	for _, stmt := range purgeByRoomNID {
+		_, err := sqlutil.TxStmt(txn, stmt).ExecContext(ctx, roomNID)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *purgeStatements) purgeStateBlocks(
+	ctx context.Context, txn *sql.Tx, roomNID types.RoomNID,
+) error {
+	// Get all stateBlockNIDs
+	stateBlockNIDs, err := s.stateSnapshot.selectStateBlockNIDsForRoomNID(ctx, txn, roomNID)
+	if err != nil {
+		return err
+	}
+	params := make([]interface{}, len(stateBlockNIDs))
+	seenNIDs := make(map[types.StateBlockNID]struct{}, len(stateBlockNIDs))
+	// dedupe NIDs
+	for k, v := range stateBlockNIDs {
+		if _, ok := seenNIDs[v]; ok {
+			continue
+		}
+		params[k] = v
+		seenNIDs[v] = struct{}{}
+	}
+
+	query := "DELETE FROM roomserver_state_block WHERE state_block_nid IN($1)"
+	return sqlutil.RunLimitedVariablesExec(ctx, query, txn, params, sqlutil.SQLite3MaxVariables)
+}
diff --git a/roomserver/storage/sqlite3/rooms_table.go b/roomserver/storage/sqlite3/rooms_table.go
index 25b611b3..7556b346 100644
--- a/roomserver/storage/sqlite3/rooms_table.go
+++ b/roomserver/storage/sqlite3/rooms_table.go
@@ -74,10 +74,14 @@ const bulkSelectRoomIDsSQL = "" +
 const bulkSelectRoomNIDsSQL = "" +
 	"SELECT room_nid FROM roomserver_rooms WHERE room_id IN ($1)"
 
+const selectRoomNIDForUpdateSQL = "" +
+	"SELECT room_nid FROM roomserver_rooms WHERE room_id = $1"
+
 type roomStatements struct {
 	db                                 *sql.DB
 	insertRoomNIDStmt                  *sql.Stmt
 	selectRoomNIDStmt                  *sql.Stmt
+	selectRoomNIDForUpdateStmt         *sql.Stmt
 	selectLatestEventNIDsStmt          *sql.Stmt
 	selectLatestEventNIDsForUpdateStmt *sql.Stmt
 	updateLatestEventNIDsStmt          *sql.Stmt
@@ -105,6 +109,7 @@ func PrepareRoomsTable(db *sql.DB) (tables.Rooms, error) {
 		//{&s.selectRoomVersionForRoomNIDsStmt, selectRoomVersionForRoomNIDsSQL},
 		{&s.selectRoomInfoStmt, selectRoomInfoSQL},
 		{&s.selectRoomIDsStmt, selectRoomIDsSQL},
+		{&s.selectRoomNIDForUpdateStmt, selectRoomNIDForUpdateSQL},
 	}.Prepare(db)
 }
 
@@ -169,6 +174,15 @@ func (s *roomStatements) SelectRoomNID(
 	return types.RoomNID(roomNID), err
 }
 
+func (s *roomStatements) SelectRoomNIDForUpdate(
+	ctx context.Context, txn *sql.Tx, roomID string,
+) (types.RoomNID, error) {
+	var roomNID int64
+	stmt := sqlutil.TxStmt(txn, s.selectRoomNIDForUpdateStmt)
+	err := stmt.QueryRowContext(ctx, roomID).Scan(&roomNID)
+	return types.RoomNID(roomNID), err
+}
+
 func (s *roomStatements) SelectLatestEventNIDs(
 	ctx context.Context, txn *sql.Tx, roomNID types.RoomNID,
 ) ([]types.EventNID, types.StateSnapshotNID, error) {
diff --git a/roomserver/storage/sqlite3/state_block_table.go b/roomserver/storage/sqlite3/state_block_table.go
index 4e67d4da..ae8181cf 100644
--- a/roomserver/storage/sqlite3/state_block_table.go
+++ b/roomserver/storage/sqlite3/state_block_table.go
@@ -24,7 +24,6 @@ import (
 
 	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
-	"github.com/matrix-org/dendrite/roomserver/storage/tables"
 	"github.com/matrix-org/dendrite/roomserver/types"
 	"github.com/matrix-org/util"
 )
@@ -68,7 +67,7 @@ func CreateStateBlockTable(db *sql.DB) error {
 	return err
 }
 
-func PrepareStateBlockTable(db *sql.DB) (tables.StateBlock, error) {
+func PrepareStateBlockTable(db *sql.DB) (*stateBlockStatements, error) {
 	s := &stateBlockStatements{
 		db: db,
 	}
diff --git a/roomserver/storage/sqlite3/state_snapshot_table.go b/roomserver/storage/sqlite3/state_snapshot_table.go
index 73827522..930ad14d 100644
--- a/roomserver/storage/sqlite3/state_snapshot_table.go
+++ b/roomserver/storage/sqlite3/state_snapshot_table.go
@@ -62,10 +62,14 @@ const bulkSelectStateBlockNIDsSQL = "" +
 	"SELECT state_snapshot_nid, state_block_nids FROM roomserver_state_snapshots" +
 	" WHERE state_snapshot_nid IN ($1) ORDER BY state_snapshot_nid ASC"
 
+const selectStateBlockNIDsForRoomNID = "" +
+	"SELECT state_block_nids FROM roomserver_state_snapshots WHERE room_nid = $1"
+
 type stateSnapshotStatements struct {
 	db                           *sql.DB
 	insertStateStmt              *sql.Stmt
 	bulkSelectStateBlockNIDsStmt *sql.Stmt
+	selectStateBlockNIDsStmt     *sql.Stmt
 }
 
 func CreateStateSnapshotTable(db *sql.DB) error {
@@ -73,7 +77,7 @@ func CreateStateSnapshotTable(db *sql.DB) error {
 	return err
 }
 
-func PrepareStateSnapshotTable(db *sql.DB) (tables.StateSnapshot, error) {
+func PrepareStateSnapshotTable(db *sql.DB) (*stateSnapshotStatements, error) {
 	s := &stateSnapshotStatements{
 		db: db,
 	}
@@ -81,6 +85,7 @@ func PrepareStateSnapshotTable(db *sql.DB) (tables.StateSnapshot, error) {
 	return s, sqlutil.StatementList{
 		{&s.insertStateStmt, insertStateSQL},
 		{&s.bulkSelectStateBlockNIDsStmt, bulkSelectStateBlockNIDsSQL},
+		{&s.selectStateBlockNIDsStmt, selectStateBlockNIDsForRoomNID},
 	}.Prepare(db)
 }
 
@@ -146,3 +151,29 @@ func (s *stateSnapshotStatements) BulkSelectStateForHistoryVisibility(
 ) ([]types.EventNID, error) {
 	return nil, tables.OptimisationNotSupportedError
 }
+
+func (s *stateSnapshotStatements) selectStateBlockNIDsForRoomNID(
+	ctx context.Context, txn *sql.Tx, roomNID types.RoomNID,
+) ([]types.StateBlockNID, error) {
+	var res []types.StateBlockNID
+	rows, err := sqlutil.TxStmt(txn, s.selectStateBlockNIDsStmt).QueryContext(ctx, roomNID)
+	if err != nil {
+		return res, nil
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectStateBlockNIDsForRoomNID: rows.close() failed")
+
+	var stateBlockNIDs []types.StateBlockNID
+	var stateBlockNIDsJSON string
+	for rows.Next() {
+		if err = rows.Scan(&stateBlockNIDsJSON); err != nil {
+			return nil, err
+		}
+		if err = json.Unmarshal([]byte(stateBlockNIDsJSON), &stateBlockNIDs); err != nil {
+			return nil, err
+		}
+
+		res = append(res, stateBlockNIDs...)
+	}
+
+	return res, rows.Err()
+}
diff --git a/roomserver/storage/sqlite3/storage.go b/roomserver/storage/sqlite3/storage.go
index 01c3f879..392edd28 100644
--- a/roomserver/storage/sqlite3/storage.go
+++ b/roomserver/storage/sqlite3/storage.go
@@ -197,6 +197,11 @@ func (d *Database) prepare(db *sql.DB, writer sqlutil.Writer, cache caching.Room
 	if err != nil {
 		return err
 	}
+	purge, err := PreparePurgeStatements(db, stateSnapshot)
+	if err != nil {
+		return err
+	}
+
 	d.Database = shared.Database{
 		DB:                  db,
 		Cache:               cache,
@@ -215,6 +220,7 @@ func (d *Database) prepare(db *sql.DB, writer sqlutil.Writer, cache caching.Room
 		PublishedTable:      published,
 		RedactionsTable:     redactions,
 		GetRoomUpdaterFn:    d.GetRoomUpdater,
+		Purge:               purge,
 	}
 	return nil
 }
diff --git a/roomserver/storage/tables/interface.go b/roomserver/storage/tables/interface.go
index 80fcf72d..64145f83 100644
--- a/roomserver/storage/tables/interface.go
+++ b/roomserver/storage/tables/interface.go
@@ -73,6 +73,7 @@ type Events interface {
 type Rooms interface {
 	InsertRoomNID(ctx context.Context, txn *sql.Tx, roomID string, roomVersion gomatrixserverlib.RoomVersion) (types.RoomNID, error)
 	SelectRoomNID(ctx context.Context, txn *sql.Tx, roomID string) (types.RoomNID, error)
+	SelectRoomNIDForUpdate(ctx context.Context, txn *sql.Tx, roomID string) (types.RoomNID, error)
 	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
@@ -173,6 +174,12 @@ type Redactions interface {
 	MarkRedactionValidated(ctx context.Context, txn *sql.Tx, redactionEventID string, validated bool) error
 }
 
+type Purge interface {
+	PurgeRoom(
+		ctx context.Context, txn *sql.Tx, roomNID types.RoomNID, roomID string,
+	) error
+}
+
 // StrippedEvent represents a stripped event for returning extracted content values.
 type StrippedEvent struct {
 	RoomID       string