fix: database switching may do nothing

backend/services/browser_service.go

@@ -81,7 +81,9 @@ func (b *browserService) Start(ctx context.Context) {
 func (b *browserService) Stop() {
 	for _, item := range b.connMap {
 		if item.client != nil {
+			if item.cancelFunc != nil {
 				item.cancelFunc()
+			}
 			item.client.Close()
 		}
 	}
@@ -227,7 +229,9 @@ func (b *browserService) CloseConnection(name string) (resp types.JSResp) {
 	if ok {
 		delete(b.connMap, name)
 		if item.client != nil {
+			if item.cancelFunc != nil {
 				item.cancelFunc()
+			}
 			item.client.Close()
 		}
 	}
@@ -287,14 +291,27 @@ func (b *browserService) getRedisClient(server string, db int) (item *connection
 	var ok bool
 	var client redis.UniversalClient
 	if item, ok = b.connMap[server]; ok {
-		client = item.client
-	} else {
+		if item.db == db {
+			return
+		}
+
+		// close previous connection if database is not the same
+		if item.cancelFunc != nil {
+			item.cancelFunc()
+		}
+		item.client.Close()
+		delete(b.connMap, server)
+	}
+
+	// recreate new connection after switch database
 	selConn := Connection().getConnection(server)
 	if selConn == nil {
 		err = fmt.Errorf("no match connection \"%s\"", server)
 		return
 	}
-		client, err = b.createRedisClient(selConn.ConnectionConfig)
+	var connConfig = selConn.ConnectionConfig
+	connConfig.LastDB = db
+	client, err = b.createRedisClient(connConfig)
 	ctx, cancelFunc := context.WithCancel(b.ctx)
 	item = &connectionItem{
 		client:      client,
@@ -303,28 +320,12 @@ func (b *browserService) getRedisClient(server string, db int) (item *connection
 		cursor:      map[int]uint64{},
 		entryCursor: map[int]entryCursor{},
 		stepSize:    int64(selConn.LoadSize),
+		db:          db,
 	}
 	if item.stepSize <= 0 {
 		item.stepSize = consts.DEFAULT_LOAD_SIZE
 	}
 	b.connMap[server] = item
-	}
-
-	// BUG: go-redis might not be executing commands on the corresponding database
-	// requiring a database switch before execute each command
-	if db >= 0 && item.db != db {
-		var rdb *redis.Client
-		if rdb, ok = client.(*redis.Client); ok && rdb != nil {
-			_, err = rdb.Pipelined(item.ctx, func(pipe redis.Pipeliner) error {
-				return pipe.Select(item.ctx, db).Err()
-			})
-			if err != nil {
-				return
-			}
-			item.db = db
-			b.connMap[server].db = db
-		}
-	}
 	return
 }