Use TransactionWriter in other component SQLite (#1209)

* Use TransactionWriter on other component SQLites

* Fix sync API tests

* Fix panic in media API

* Fix a couple of transactions

* Fix wrong query, add some logging output

* Add debug logging into StoreEvent

* Adjust InsertRoomNID

* Update logging

11 files changed, 222 insertions, 132 deletions

diff --git a/syncapi/storage/shared/syncserver.go b/syncapi/storage/shared/syncserver.go
index 32079291..e1312671 100644
--- a/syncapi/storage/shared/syncserver.go
+++ b/syncapi/storage/shared/syncserver.go
@@ -281,16 +281,16 @@ func (d *Database) WriteEvent(
 			ctx, txn, ev, addStateEventIDs, removeStateEventIDs, transactionID, excludeFromSync,
 		)
 		if err != nil {
-			return err
+			return fmt.Errorf("d.OutputEvents.InsertEvent: %w", err)
 		}
 		pduPosition = pos
 
 		if err = d.Topology.InsertEventInTopology(ctx, txn, ev, pos); err != nil {
-			return err
+			return fmt.Errorf("d.Topology.InsertEventInTopology: %w", err)
 		}
 
 		if err = d.handleBackwardExtremities(ctx, txn, ev); err != nil {
-			return err
+			return fmt.Errorf("d.handleBackwardExtremities: %w", err)
 		}
 
 		if len(addStateEvents) == 0 && len(removeStateEventIDs) == 0 {
@@ -313,7 +313,7 @@ func (d *Database) updateRoomState(
 	// remove first, then add, as we do not ever delete state, but do replace state which is a remove followed by an add.
 	for _, eventID := range removedEventIDs {
 		if err := d.CurrentRoomState.DeleteRoomStateByEventID(ctx, txn, eventID); err != nil {
-			return err
+			return fmt.Errorf("d.CurrentRoomState.DeleteRoomStateByEventID: %w", err)
 		}
 	}
 
@@ -326,13 +326,13 @@ func (d *Database) updateRoomState(
 		if event.Type() == "m.room.member" {
 			value, err := event.Membership()
 			if err != nil {
-				return err
+				return fmt.Errorf("event.Membership: %w", err)
 			}
 			membership = &value
 		}
 
 		if err := d.CurrentRoomState.UpsertRoomState(ctx, txn, event, membership, pduPosition); err != nil {
-			return err
+			return fmt.Errorf("d.CurrentRoomState.UpsertRoomState: %w", err)
 		}
 	}
 
diff --git a/syncapi/storage/sqlite3/account_data_table.go b/syncapi/storage/sqlite3/account_data_table.go
index ae5caa4e..609cef14 100644
--- a/syncapi/storage/sqlite3/account_data_table.go
+++ b/syncapi/storage/sqlite3/account_data_table.go
@@ -20,6 +20,7 @@ import (
 	"database/sql"
 
 	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/syncapi/storage/tables"
 	"github.com/matrix-org/dendrite/syncapi/types"
 	"github.com/matrix-org/gomatrixserverlib"
@@ -49,6 +50,8 @@ const selectMaxAccountDataIDSQL = "" +
 	"SELECT MAX(id) FROM syncapi_account_data_type"
 
 type accountDataStatements struct {
+	db                           *sql.DB
+	writer                       *sqlutil.TransactionWriter
 	streamIDStatements           *streamIDStatements
 	insertAccountDataStmt        *sql.Stmt
 	selectMaxAccountDataIDStmt   *sql.Stmt
@@ -57,6 +60,8 @@ type accountDataStatements struct {
 
 func NewSqliteAccountDataTable(db *sql.DB, streamID *streamIDStatements) (tables.AccountData, error) {
 	s := &accountDataStatements{
+		db:                 db,
+		writer:             sqlutil.NewTransactionWriter(),
 		streamIDStatements: streamID,
 	}
 	_, err := db.Exec(accountDataSchema)
@@ -79,12 +84,15 @@ func (s *accountDataStatements) InsertAccountData(
 	ctx context.Context, txn *sql.Tx,
 	userID, roomID, dataType string,
 ) (pos types.StreamPosition, err error) {
-	pos, err = s.streamIDStatements.nextStreamID(ctx, txn)
-	if err != nil {
-		return
-	}
-	_, err = txn.Stmt(s.insertAccountDataStmt).ExecContext(ctx, pos, userID, roomID, dataType)
-	return
+	return pos, s.writer.Do(s.db, nil, func(txn *sql.Tx) error {
+		var err error
+		pos, err = s.streamIDStatements.nextStreamID(ctx, txn)
+		if err != nil {
+			return err
+		}
+		_, err = txn.Stmt(s.insertAccountDataStmt).ExecContext(ctx, pos, userID, roomID, dataType)
+		return err
+	})
 }
 
 func (s *accountDataStatements) SelectAccountDataInRange(
diff --git a/syncapi/storage/sqlite3/backwards_extremities_table.go b/syncapi/storage/sqlite3/backwards_extremities_table.go
index e16e54a6..1aeb041f 100644
--- a/syncapi/storage/sqlite3/backwards_extremities_table.go
+++ b/syncapi/storage/sqlite3/backwards_extremities_table.go
@@ -19,6 +19,7 @@ import (
 	"database/sql"
 
 	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/syncapi/storage/tables"
 )
 
@@ -47,13 +48,18 @@ const deleteBackwardExtremitySQL = "" +
 	"DELETE FROM syncapi_backward_extremities WHERE room_id = $1 AND prev_event_id = $2"
 
 type backwardExtremitiesStatements struct {
+	db                                   *sql.DB
+	writer                               *sqlutil.TransactionWriter
 	insertBackwardExtremityStmt          *sql.Stmt
 	selectBackwardExtremitiesForRoomStmt *sql.Stmt
 	deleteBackwardExtremityStmt          *sql.Stmt
 }
 
 func NewSqliteBackwardsExtremitiesTable(db *sql.DB) (tables.BackwardsExtremities, error) {
-	s := &backwardExtremitiesStatements{}
+	s := &backwardExtremitiesStatements{
+		db:     db,
+		writer: sqlutil.NewTransactionWriter(),
+	}
 	_, err := db.Exec(backwardExtremitiesSchema)
 	if err != nil {
 		return nil, err
@@ -73,8 +79,10 @@ func NewSqliteBackwardsExtremitiesTable(db *sql.DB) (tables.BackwardsExtremities
 func (s *backwardExtremitiesStatements) InsertsBackwardExtremity(
 	ctx context.Context, txn *sql.Tx, roomID, eventID string, prevEventID string,
 ) (err error) {
-	_, err = txn.Stmt(s.insertBackwardExtremityStmt).ExecContext(ctx, roomID, eventID, prevEventID)
-	return
+	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		_, err := txn.Stmt(s.insertBackwardExtremityStmt).ExecContext(ctx, roomID, eventID, prevEventID)
+		return err
+	})
 }
 
 func (s *backwardExtremitiesStatements) SelectBackwardExtremitiesForRoom(
@@ -102,6 +110,8 @@ func (s *backwardExtremitiesStatements) SelectBackwardExtremitiesForRoom(
 func (s *backwardExtremitiesStatements) DeleteBackwardExtremity(
 	ctx context.Context, txn *sql.Tx, roomID, knownEventID string,
 ) (err error) {
-	_, err = txn.Stmt(s.deleteBackwardExtremityStmt).ExecContext(ctx, roomID, knownEventID)
-	return
+	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		_, err := txn.Stmt(s.deleteBackwardExtremityStmt).ExecContext(ctx, roomID, knownEventID)
+		return err
+	})
 }
diff --git a/syncapi/storage/sqlite3/current_room_state_table.go b/syncapi/storage/sqlite3/current_room_state_table.go
index 85f212ad..08b42f5b 100644
--- a/syncapi/storage/sqlite3/current_room_state_table.go
+++ b/syncapi/storage/sqlite3/current_room_state_table.go
@@ -84,6 +84,8 @@ const selectEventsWithEventIDsSQL = "" +
 	" FROM syncapi_current_room_state WHERE event_id IN ($1)"
 
 type currentRoomStateStatements struct {
+	db                              *sql.DB
+	writer                          *sqlutil.TransactionWriter
 	streamIDStatements              *streamIDStatements
 	upsertRoomStateStmt             *sql.Stmt
 	deleteRoomStateByEventIDStmt    *sql.Stmt
@@ -95,6 +97,8 @@ type currentRoomStateStatements struct {
 
 func NewSqliteCurrentRoomStateTable(db *sql.DB, streamID *streamIDStatements) (tables.CurrentRoomState, error) {
 	s := &currentRoomStateStatements{
+		db:                 db,
+		writer:             sqlutil.NewTransactionWriter(),
 		streamIDStatements: streamID,
 	}
 	_, err := db.Exec(currentRoomStateSchema)
@@ -196,9 +200,11 @@ func (s *currentRoomStateStatements) SelectCurrentState(
 func (s *currentRoomStateStatements) DeleteRoomStateByEventID(
 	ctx context.Context, txn *sql.Tx, eventID string,
 ) error {
-	stmt := sqlutil.TxStmt(txn, s.deleteRoomStateByEventIDStmt)
-	_, err := stmt.ExecContext(ctx, eventID)
-	return err
+	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		stmt := sqlutil.TxStmt(txn, s.deleteRoomStateByEventIDStmt)
+		_, err := stmt.ExecContext(ctx, eventID)
+		return err
+	})
 }
 
 func (s *currentRoomStateStatements) UpsertRoomState(
@@ -219,20 +225,22 @@ func (s *currentRoomStateStatements) UpsertRoomState(
 	}
 
 	// upsert state event
-	stmt := sqlutil.TxStmt(txn, s.upsertRoomStateStmt)
-	_, err = stmt.ExecContext(
-		ctx,
-		event.RoomID(),
-		event.EventID(),
-		event.Type(),
-		event.Sender(),
-		containsURL,
-		*event.StateKey(),
-		headeredJSON,
-		membership,
-		addedAt,
-	)
-	return err
+	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		stmt := sqlutil.TxStmt(txn, s.upsertRoomStateStmt)
+		_, err := stmt.ExecContext(
+			ctx,
+			event.RoomID(),
+			event.EventID(),
+			event.Type(),
+			event.Sender(),
+			containsURL,
+			*event.StateKey(),
+			headeredJSON,
+			membership,
+			addedAt,
+		)
+		return err
+	})
 }
 
 func (s *currentRoomStateStatements) SelectEventsWithEventIDs(
diff --git a/syncapi/storage/sqlite3/filter_table.go b/syncapi/storage/sqlite3/filter_table.go
index 8b26759d..3e8a4655 100644
--- a/syncapi/storage/sqlite3/filter_table.go
+++ b/syncapi/storage/sqlite3/filter_table.go
@@ -20,6 +20,7 @@ import (
 	"encoding/json"
 	"fmt"
 
+	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/syncapi/storage/tables"
 	"github.com/matrix-org/gomatrixserverlib"
 )
@@ -50,6 +51,8 @@ const insertFilterSQL = "" +
 	"INSERT INTO syncapi_filter (filter, localpart) VALUES ($1, $2)"
 
 type filterStatements struct {
+	db                          *sql.DB
+	writer                      *sqlutil.TransactionWriter
 	selectFilterStmt            *sql.Stmt
 	selectFilterIDByContentStmt *sql.Stmt
 	insertFilterStmt            *sql.Stmt
@@ -60,7 +63,10 @@ func NewSqliteFilterTable(db *sql.DB) (tables.Filter, error) {
 	if err != nil {
 		return nil, err
 	}
-	s := &filterStatements{}
+	s := &filterStatements{
+		db:     db,
+		writer: sqlutil.NewTransactionWriter(),
+	}
 	if s.selectFilterStmt, err = db.Prepare(selectFilterSQL); err != nil {
 		return nil, err
 	}
@@ -108,30 +114,33 @@ func (s *filterStatements) InsertFilter(
 		return "", err
 	}
 
-	// Check if filter already exists in the database using its localpart and content
-	//
-	// This can result in a race condition when two clients try to insert the
-	// same filter and localpart at the same time, however this is not a
-	// problem as both calls will result in the same filterID
-	err = s.selectFilterIDByContentStmt.QueryRowContext(ctx,
-		localpart, filterJSON).Scan(&existingFilterID)
-	if err != nil && err != sql.ErrNoRows {
-		return "", err
-	}
-	// If it does, return the existing ID
-	if existingFilterID != "" {
-		return existingFilterID, err
-	}
-
-	// Otherwise insert the filter and return the new ID
-	res, err := s.insertFilterStmt.ExecContext(ctx, filterJSON, localpart)
-	if err != nil {
-		return "", err
-	}
-	rowid, err := res.LastInsertId()
-	if err != nil {
-		return "", err
-	}
-	filterID = fmt.Sprintf("%d", rowid)
+	err = s.writer.Do(s.db, nil, func(txn *sql.Tx) error {
+		// Check if filter already exists in the database using its localpart and content
+		//
+		// This can result in a race condition when two clients try to insert the
+		// same filter and localpart at the same time, however this is not a
+		// problem as both calls will result in the same filterID
+		err = s.selectFilterIDByContentStmt.QueryRowContext(ctx,
+			localpart, filterJSON).Scan(&existingFilterID)
+		if err != nil && err != sql.ErrNoRows {
+			return err
+		}
+		// If it does, return the existing ID
+		if existingFilterID != "" {
+			return nil
+		}
+
+		// Otherwise insert the filter and return the new ID
+		res, err := s.insertFilterStmt.ExecContext(ctx, filterJSON, localpart)
+		if err != nil {
+			return err
+		}
+		rowid, err := res.LastInsertId()
+		if err != nil {
+			return err
+		}
+		filterID = fmt.Sprintf("%d", rowid)
+		return nil
+	})
 	return
 }
diff --git a/syncapi/storage/sqlite3/invites_table.go b/syncapi/storage/sqlite3/invites_table.go
index aa051388..19e7a7c6 100644
--- a/syncapi/storage/sqlite3/invites_table.go
+++ b/syncapi/storage/sqlite3/invites_table.go
@@ -58,6 +58,8 @@ const selectMaxInviteIDSQL = "" +
 	"SELECT MAX(id) FROM syncapi_invite_events"
 
 type inviteEventsStatements struct {
+	db                            *sql.DB
+	writer                        *sqlutil.TransactionWriter
 	streamIDStatements            *streamIDStatements
 	insertInviteEventStmt         *sql.Stmt
 	selectInviteEventsInRangeStmt *sql.Stmt
@@ -67,6 +69,8 @@ type inviteEventsStatements struct {
 
 func NewSqliteInvitesTable(db *sql.DB, streamID *streamIDStatements) (tables.Invites, error) {
 	s := &inviteEventsStatements{
+		db:                 db,
+		writer:             sqlutil.NewTransactionWriter(),
 		streamIDStatements: streamID,
 	}
 	_, err := db.Exec(inviteEventsSchema)
@@ -91,36 +95,45 @@ func NewSqliteInvitesTable(db *sql.DB, streamID *streamIDStatements) (tables.Inv
 func (s *inviteEventsStatements) InsertInviteEvent(
 	ctx context.Context, txn *sql.Tx, inviteEvent gomatrixserverlib.HeaderedEvent,
 ) (streamPos types.StreamPosition, err error) {
-	streamPos, err = s.streamIDStatements.nextStreamID(ctx, txn)
-	if err != nil {
-		return
-	}
+	err = s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		var err error
+		streamPos, err = s.streamIDStatements.nextStreamID(ctx, txn)
+		if err != nil {
+			return err
+		}
 
-	var headeredJSON []byte
-	headeredJSON, err = json.Marshal(inviteEvent)
-	if err != nil {
-		return
-	}
+		var headeredJSON []byte
+		headeredJSON, err = json.Marshal(inviteEvent)
+		if err != nil {
+			return err
+		}
 
-	_, err = txn.Stmt(s.insertInviteEventStmt).ExecContext(
-		ctx,
-		streamPos,
-		inviteEvent.RoomID(),
-		inviteEvent.EventID(),
-		*inviteEvent.StateKey(),
-		headeredJSON,
-	)
+		_, err = txn.Stmt(s.insertInviteEventStmt).ExecContext(
+			ctx,
+			streamPos,
+			inviteEvent.RoomID(),
+			inviteEvent.EventID(),
+			*inviteEvent.StateKey(),
+			headeredJSON,
+		)
+		return err
+	})
 	return
 }
 
 func (s *inviteEventsStatements) DeleteInviteEvent(
 	ctx context.Context, inviteEventID string,
 ) (types.StreamPosition, error) {
-	streamPos, err := s.streamIDStatements.nextStreamID(ctx, nil)
-	if err != nil {
-		return streamPos, err
-	}
-	_, err = s.deleteInviteEventStmt.ExecContext(ctx, streamPos, inviteEventID)
+	var streamPos types.StreamPosition
+	err := s.writer.Do(s.db, nil, func(txn *sql.Tx) error {
+		var err error
+		streamPos, err = s.streamIDStatements.nextStreamID(ctx, nil)
+		if err != nil {
+			return err
+		}
+		_, err = s.deleteInviteEventStmt.ExecContext(ctx, streamPos, inviteEventID)
+		return err
+	})
 	return streamPos, err
 }
 
diff --git a/syncapi/storage/sqlite3/output_room_events_table.go b/syncapi/storage/sqlite3/output_room_events_table.go
index da2ea3f6..12b4dbab 100644
--- a/syncapi/storage/sqlite3/output_room_events_table.go
+++ b/syncapi/storage/sqlite3/output_room_events_table.go
@@ -104,6 +104,8 @@ const selectStateInRangeSQL = "" +
 	" LIMIT $8" // limit
 
 type outputRoomEventsStatements struct {
+	db                            *sql.DB
+	writer                        *sqlutil.TransactionWriter
 	streamIDStatements            *streamIDStatements
 	insertEventStmt               *sql.Stmt
 	selectEventsStmt              *sql.Stmt
@@ -117,6 +119,8 @@ type outputRoomEventsStatements struct {
 
 func NewSqliteEventsTable(db *sql.DB, streamID *streamIDStatements) (tables.Events, error) {
 	s := &outputRoomEventsStatements{
+		db:                 db,
+		writer:             sqlutil.NewTransactionWriter(),
 		streamIDStatements: streamID,
 	}
 	_, err := db.Exec(outputRoomEventsSchema)
@@ -155,8 +159,10 @@ func (s *outputRoomEventsStatements) UpdateEventJSON(ctx context.Context, event
 	if err != nil {
 		return err
 	}
-	_, err = s.updateEventJSONStmt.ExecContext(ctx, headeredJSON, event.EventID())
-	return err
+	return s.writer.Do(s.db, nil, func(txn *sql.Tx) error {
+		_, err = s.updateEventJSONStmt.ExecContext(ctx, headeredJSON, event.EventID())
+		return err
+	})
 }
 
 // selectStateInRange returns the state events between the two given PDU stream positions, exclusive of oldPos, inclusive of newPos.
@@ -267,7 +273,7 @@ func (s *outputRoomEventsStatements) InsertEvent(
 	ctx context.Context, txn *sql.Tx,
 	event *gomatrixserverlib.HeaderedEvent, addState, removeState []string,
 	transactionID *api.TransactionID, excludeFromSync bool,
-) (streamPos types.StreamPosition, err error) {
+) (types.StreamPosition, error) {
 	var txnID *string
 	var sessionID *int64
 	if transactionID != nil {
@@ -284,43 +290,47 @@ func (s *outputRoomEventsStatements) InsertEvent(
 	}
 
 	var headeredJSON []byte
-	headeredJSON, err = json.Marshal(event)
-	if err != nil {
-		return
-	}
-
-	streamPos, err = s.streamIDStatements.nextStreamID(ctx, txn)
+	headeredJSON, err := json.Marshal(event)
 	if err != nil {
-		return
+		return 0, err
 	}
 
 	addStateJSON, err := json.Marshal(addState)
 	if err != nil {
-		return
+		return 0, err
 	}
 	removeStateJSON, err := json.Marshal(removeState)
 	if err != nil {
-		return
+		return 0, err
 	}
 
-	insertStmt := sqlutil.TxStmt(txn, s.insertEventStmt)
-	_, err = insertStmt.ExecContext(
-		ctx,
-		streamPos,
-		event.RoomID(),
-		event.EventID(),
-		headeredJSON,
-		event.Type(),
-		event.Sender(),
-		containsURL,
-		string(addStateJSON),
-		string(removeStateJSON),
-		sessionID,
-		txnID,
-		excludeFromSync,
-		excludeFromSync,
-	)
-	return
+	var streamPos types.StreamPosition
+	err = s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		streamPos, err = s.streamIDStatements.nextStreamID(ctx, txn)
+		if err != nil {
+			return err
+		}
+
+		insertStmt := sqlutil.TxStmt(txn, s.insertEventStmt)
+		_, ierr := insertStmt.ExecContext(
+			ctx,
+			streamPos,
+			event.RoomID(),
+			event.EventID(),
+			headeredJSON,
+			event.Type(),
+			event.Sender(),
+			containsURL,
+			string(addStateJSON),
+			string(removeStateJSON),
+			sessionID,
+			txnID,
+			excludeFromSync,
+			excludeFromSync,
+		)
+		return ierr
+	})
+	return streamPos, err
 }
 
 func (s *outputRoomEventsStatements) SelectRecentEvents(
diff --git a/syncapi/storage/sqlite3/output_room_events_topology_table.go b/syncapi/storage/sqlite3/output_room_events_topology_table.go
index 811dfa4f..2e71e8f3 100644
--- a/syncapi/storage/sqlite3/output_room_events_topology_table.go
+++ b/syncapi/storage/sqlite3/output_room_events_topology_table.go
@@ -66,6 +66,8 @@ const selectMaxPositionInTopologySQL = "" +
 	" WHERE room_id = $1 ORDER BY stream_position DESC"
 
 type outputRoomEventsTopologyStatements struct {
+	db                              *sql.DB
+	writer                          *sqlutil.TransactionWriter
 	insertEventInTopologyStmt       *sql.Stmt
 	selectEventIDsInRangeASCStmt    *sql.Stmt
 	selectEventIDsInRangeDESCStmt   *sql.Stmt
@@ -74,7 +76,10 @@ type outputRoomEventsTopologyStatements struct {
 }
 
 func NewSqliteTopologyTable(db *sql.DB) (tables.Topology, error) {
-	s := &outputRoomEventsTopologyStatements{}
+	s := &outputRoomEventsTopologyStatements{
+		db:     db,
+		writer: sqlutil.NewTransactionWriter(),
+	}
 	_, err := db.Exec(outputRoomEventsTopologySchema)
 	if err != nil {
 		return nil, err
@@ -102,11 +107,13 @@ func NewSqliteTopologyTable(db *sql.DB) (tables.Topology, error) {
 func (s *outputRoomEventsTopologyStatements) InsertEventInTopology(
 	ctx context.Context, txn *sql.Tx, event *gomatrixserverlib.HeaderedEvent, pos types.StreamPosition,
 ) (err error) {
-	stmt := sqlutil.TxStmt(txn, s.insertEventInTopologyStmt)
-	_, err = stmt.ExecContext(
-		ctx, event.EventID(), event.Depth(), event.RoomID(), pos,
-	)
-	return
+	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		stmt := sqlutil.TxStmt(txn, s.insertEventInTopologyStmt)
+		_, err := stmt.ExecContext(
+			ctx, event.EventID(), event.Depth(), event.RoomID(), pos,
+		)
+		return err
+	})
 }
 
 func (s *outputRoomEventsTopologyStatements) SelectEventIDsInRange(
diff --git a/syncapi/storage/sqlite3/send_to_device_table.go b/syncapi/storage/sqlite3/send_to_device_table.go
index 42bd3c19..88b319fb 100644
--- a/syncapi/storage/sqlite3/send_to_device_table.go
+++ b/syncapi/storage/sqlite3/send_to_device_table.go
@@ -72,13 +72,18 @@ const deleteSendToDeviceMessagesSQL = `
 `
 
 type sendToDeviceStatements struct {
+	db                             *sql.DB
+	writer                         *sqlutil.TransactionWriter
 	insertSendToDeviceMessageStmt  *sql.Stmt
 	selectSendToDeviceMessagesStmt *sql.Stmt
 	countSendToDeviceMessagesStmt  *sql.Stmt
 }
 
 func NewSqliteSendToDeviceTable(db *sql.DB) (tables.SendToDevice, error) {
-	s := &sendToDeviceStatements{}
+	s := &sendToDeviceStatements{
+		db:     db,
+		writer: sqlutil.NewTransactionWriter(),
+	}
 	_, err := db.Exec(sendToDeviceSchema)
 	if err != nil {
 		return nil, err
@@ -98,8 +103,10 @@ func NewSqliteSendToDeviceTable(db *sql.DB) (tables.SendToDevice, error) {
 func (s *sendToDeviceStatements) InsertSendToDeviceMessage(
 	ctx context.Context, txn *sql.Tx, userID, deviceID, content string,
 ) (err error) {
-	_, err = sqlutil.TxStmt(txn, s.insertSendToDeviceMessageStmt).ExecContext(ctx, userID, deviceID, content)
-	return
+	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		_, err := sqlutil.TxStmt(txn, s.insertSendToDeviceMessageStmt).ExecContext(ctx, userID, deviceID, content)
+		return err
+	})
 }
 
 func (s *sendToDeviceStatements) CountSendToDeviceMessages(
@@ -156,8 +163,10 @@ func (s *sendToDeviceStatements) UpdateSentSendToDeviceMessages(
 	for k, v := range nids {
 		params[k+1] = v
 	}
-	_, err = txn.ExecContext(ctx, query, params...)
-	return
+	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		_, err := txn.ExecContext(ctx, query, params...)
+		return err
+	})
 }
 
 func (s *sendToDeviceStatements) DeleteSendToDeviceMessages(
@@ -168,6 +177,8 @@ func (s *sendToDeviceStatements) DeleteSendToDeviceMessages(
 	for k, v := range nids {
 		params[k] = v
 	}
-	_, err = txn.ExecContext(ctx, query, params...)
-	return
+	return s.writer.Do(s.db, txn, func(txn *sql.Tx) error {
+		_, err := txn.ExecContext(ctx, query, params...)
+		return err
+	})
 }
diff --git a/syncapi/storage/sqlite3/stream_id_table.go b/syncapi/storage/sqlite3/stream_id_table.go
index 57abd9c4..cf3eed5b 100644
--- a/syncapi/storage/sqlite3/stream_id_table.go
+++ b/syncapi/storage/sqlite3/stream_id_table.go
@@ -27,11 +27,15 @@ const selectStreamIDStmt = "" +
 	"SELECT stream_id FROM syncapi_stream_id WHERE stream_name = $1"
 
 type streamIDStatements struct {
+	db                   *sql.DB
+	writer               *sqlutil.TransactionWriter
 	increaseStreamIDStmt *sql.Stmt
 	selectStreamIDStmt   *sql.Stmt
 }
 
 func (s *streamIDStatements) prepare(db *sql.DB) (err error) {
+	s.db = db
+	s.writer = sqlutil.NewTransactionWriter()
 	_, err = db.Exec(streamIDTableSchema)
 	if err != nil {
 		return
@@ -48,11 +52,14 @@ func (s *streamIDStatements) prepare(db *sql.DB) (err error) {
 func (s *streamIDStatements) nextStreamID(ctx context.Context, txn *sql.Tx) (pos types.StreamPosition, err error) {
 	increaseStmt := sqlutil.TxStmt(txn, s.increaseStreamIDStmt)
 	selectStmt := sqlutil.TxStmt(txn, s.selectStreamIDStmt)
-	if _, err = increaseStmt.ExecContext(ctx, "global"); err != nil {
-		return
-	}
-	if err = selectStmt.QueryRowContext(ctx, "global").Scan(&pos); err != nil {
-		return
-	}
+	err = s.writer.Do(s.db, nil, func(txn *sql.Tx) error {
+		if _, ierr := increaseStmt.ExecContext(ctx, "global"); err != nil {
+			return ierr
+		}
+		if serr := selectStmt.QueryRowContext(ctx, "global").Scan(&pos); err != nil {
+			return serr
+		}
+		return nil
+	})
 	return
 }
diff --git a/syncapi/storage/storage_test.go b/syncapi/storage/storage_test.go
index feacbc18..474d3222 100644
--- a/syncapi/storage/storage_test.go
+++ b/syncapi/storage/storage_test.go
@@ -5,6 +5,7 @@ import (
 	"crypto/ed25519"
 	"encoding/json"
 	"fmt"
+	"os"
 	"testing"
 	"time"
 
@@ -52,7 +53,13 @@ func MustCreateEvent(t *testing.T, roomID string, prevs []gomatrixserverlib.Head
 }
 
 func MustCreateDatabase(t *testing.T) storage.Database {
-	db, err := sqlite3.NewDatabase("file::memory:")
+	dbname := fmt.Sprintf("test_%s.db", t.Name())
+	if _, err := os.Stat(dbname); err == nil {
+		if err = os.Remove(dbname); err != nil {
+			t.Fatalf("tried to delete stale test database but failed: %s", err)
+		}
+	}
+	db, err := sqlite3.NewDatabase(fmt.Sprintf("file:%s", dbname))
 	if err != nil {
 		t.Fatalf("NewSyncServerDatasource returned %s", err)
 	}