Request DB only once per request

src/github.com/matrix-org/dendrite/clientapi/auth/storage/accounts/account_data_table.go

@@ -42,7 +42,7 @@ const insertAccountDataSQL = `
 `
 
 const selectAccountDataSQL = "" +
-	"SELECT type, content FROM account_data WHERE localpart = $1 AND room_id = $2"
+	"SELECT room_id, type, content FROM account_data WHERE localpart = $1"
 
 const deleteAccountDataSQL = "" +
 	"DELETE FROM account_data WHERE localpart = $1 AND room_id = $2 AND type = $3"
@@ -71,28 +71,38 @@ func (s *accountDataStatements) insertAccountData(localpart string, roomID strin
 	return
 }
 
-func (s *accountDataStatements) selectAccountData(localpart string, roomID string) ([]gomatrixserverlib.ClientEvent, error) {
+func (s *accountDataStatements) selectAccountData(localpart string) (
-	events := []gomatrixserverlib.ClientEvent{}
+	global []gomatrixserverlib.ClientEvent,
-
+	rooms map[string][]gomatrixserverlib.ClientEvent,
-	rows, err := s.selectAccountDataStmt.Query(localpart, roomID)
+	err error,
+) {
+	rows, err := s.selectAccountDataStmt.Query(localpart)
 	if err != nil {
-		return events, err
+		return
 	}
 
+	rooms = make(map[string][]gomatrixserverlib.ClientEvent)
+
 	for rows.Next() {
+		var roomID string
 		var dataType string
 		var content []byte
 
-		if err := rows.Scan(&dataType, &content); err != nil && err != sql.ErrNoRows {
+		if err = rows.Scan(&roomID, &dataType, &content); err != nil && err != sql.ErrNoRows {
-			return events, err
+			return
 		}
 
 		ac := gomatrixserverlib.ClientEvent{
 			Type:    dataType,
 			Content: content,
 		}
-		events = append(events, ac)
+
+		if len(roomID) > 0 {
+			rooms[roomID] = append(rooms[roomID], ac)
+		} else {
+			global = append(global, ac)
+		}
 	}
 
-	return events, nil
+	return
 }

src/github.com/matrix-org/dendrite/clientapi/auth/storage/accounts/storage.go

@@ -199,14 +199,14 @@ func (d *Database) SaveAccountData(localpart string, roomID string, dataType str
 }
 
 // GetAccountData returns account data related to a given localpart
-// If a non-empty string is provided as the room ID, returns all account data
-// related to the room
-// If an empty string is provided as the room ID, returns all account data that
-// aren't related to any room
 // If no account data could be found, returns an empty arrays
 // Returns an error if there was an issue with the retrieval
-func (d *Database) GetAccountData(localpart string, roomID string) ([]gomatrixserverlib.ClientEvent, error) {
+func (d *Database) GetAccountData(localpart string) (
-	return d.accountDatas.selectAccountData(localpart, roomID)
+	global []gomatrixserverlib.ClientEvent,
+	rooms map[string][]gomatrixserverlib.ClientEvent,
+	err error,
+) {
+	return d.accountDatas.selectAccountData(localpart)
 }
 
 func hashPassword(plaintext string) (hash string, err error) {

src/github.com/matrix-org/dendrite/syncapi/sync/requestpool.go

@@ -114,24 +114,24 @@ func (rp *RequestPool) currentSyncForUser(req syncRequest, currentPos types.Stre
 }
 
 func (rp *RequestPool) appendAccountData(data *types.Response, userID string) (*types.Response, error) {
+	// TODO: We currently send all account data on every sync response, we should instead send data
+	// that has changed on incremental sync responses
 	localpart, _, err := gomatrixserverlib.SplitID('@', userID)
 	if err != nil {
 		return nil, err
 	}
 
-	events, err := rp.accountDB.GetAccountData(localpart, "")
+	global, rooms, err := rp.accountDB.GetAccountData(localpart)
 	if err != nil {
 		return nil, err
 	}
-	data.AccountData.Events = events
+	data.AccountData.Events = global
 
 	for r, j := range data.Rooms.Join {
-		events, err := rp.accountDB.GetAccountData(localpart, r)
+		if len(rooms[r]) > 0 {
-		if err != nil {
+			j.AccountData.Events = rooms[r]
-			return nil, err
+			data.Rooms.Join[r] = j
 		}
-		j.AccountData.Events = events
-		data.Rooms.Join[r] = j
 	}
 
 	return data, nil