selectAccountDataByType return ClientEvent pointer instead of slice of ClientEvent (#798)

This pull request is an attempt to fix #773.

Signed-off-by: Kouame Behouba Manassé behouba@gmail.com

clientapi/auth/storage/accounts/account_data_table.go

@@ -120,29 +120,18 @@ func (s *accountDataStatements) selectAccountData(
 
 func (s *accountDataStatements) selectAccountDataByType(
 	ctx context.Context, localpart, roomID, dataType string,
-) (data []gomatrixserverlib.ClientEvent, err error) {
-	data = []gomatrixserverlib.ClientEvent{}
-
+) (data *gomatrixserverlib.ClientEvent, err error) {
 	stmt := s.selectAccountDataByTypeStmt
-	rows, err := stmt.QueryContext(ctx, localpart, roomID, dataType)
-	if err != nil {
-		return
-	}
-
-	for rows.Next() {
 	var content []byte
 
-		if err = rows.Scan(&content); err != nil {
+	if err = stmt.QueryRowContext(ctx, localpart, roomID, dataType).Scan(&content); err != nil {
 		return
 	}
 
-		ac := gomatrixserverlib.ClientEvent{
+	data = &gomatrixserverlib.ClientEvent{
 		Type:    dataType,
 		Content: content,
 	}
 
-		data = append(data, ac)
-	}
-
 	return
 }

clientapi/auth/storage/accounts/storage.go

@@ -263,11 +263,11 @@ func (d *Database) GetAccountData(ctx context.Context, localpart string) (
 
 // GetAccountDataByType returns account data matching a given
 // localpart, room ID and type.
-// If no account data could be found, returns an empty array
+// If no account data could be found, returns nil
 // Returns an error if there was an issue with the retrieval
 func (d *Database) GetAccountDataByType(
 	ctx context.Context, localpart, roomID, dataType string,
-) (data []gomatrixserverlib.ClientEvent, err error) {
+) (data *gomatrixserverlib.ClientEvent, err error) {
 	return d.accountDatas.selectAccountDataByType(
 		ctx, localpart, roomID, dataType,
 	)

clientapi/routing/room_tagging.go

@@ -59,7 +59,7 @@ func GetTags(
 		return httputil.LogThenError(req, err)
 	}
 
-	if len(data) == 0 {
+	if data == nil {
 		return util.JSONResponse{
 			Code: http.StatusOK,
 			JSON: struct{}{},
@@ -68,7 +68,7 @@ func GetTags(
 
 	return util.JSONResponse{
 		Code: http.StatusOK,
-		JSON: data[0].Content,
+		JSON: data.Content,
 	}
 }
 
@@ -103,8 +103,8 @@ func PutTag(
 	}
 
 	var tagContent gomatrix.TagContent
-	if len(data) > 0 {
-		if err = json.Unmarshal(data[0].Content, &tagContent); err != nil {
+	if data != nil {
+		if err = json.Unmarshal(data.Content, &tagContent); err != nil {
 			return httputil.LogThenError(req, err)
 		}
 	} else {
@@ -155,7 +155,7 @@ func DeleteTag(
 	}
 
 	// If there are no tags in the database, exit
-	if len(data) == 0 {
+	if data == nil {
 		// Spec only defines 200 responses for this endpoint so we don't return anything else.
 		return util.JSONResponse{
 			Code: http.StatusOK,
@@ -164,7 +164,7 @@ func DeleteTag(
 	}
 
 	var tagContent gomatrix.TagContent
-	err = json.Unmarshal(data[0].Content, &tagContent)
+	err = json.Unmarshal(data.Content, &tagContent)
 	if err != nil {
 		return httputil.LogThenError(req, err)
 	}
@@ -204,7 +204,7 @@ func obtainSavedTags(
 	userID string,
 	roomID string,
 	accountDB *accounts.Database,
-) (string, []gomatrixserverlib.ClientEvent, error) {
+) (string, *gomatrixserverlib.ClientEvent, error) {
 	localpart, _, err := gomatrixserverlib.SplitID('@', userID)
 	if err != nil {
 		return "", nil, err

syncapi/sync/requestpool.go

@@ -196,13 +196,13 @@ func (rp *RequestPool) appendAccountData(
 		events := []gomatrixserverlib.ClientEvent{}
 		// Request the missing data from the database
 		for _, dataType := range dataTypes {
-			evs, err := rp.accountDB.GetAccountDataByType(
+			event, err := rp.accountDB.GetAccountDataByType(
 				req.ctx, localpart, roomID, dataType,
 			)
 			if err != nil {
 				return nil, err
 			}
-			events = append(events, evs...)
+			events = append(events, *event)
 		}
 
 		// Append the data to the response