tacitus: some refactoring

database_client.go

@@ -0,0 +1,8 @@
+package tacitus
+
+type DatabaseClientService interface {
+	Open() error
+	Close() error
+	TradeService() TradeService
+	SetLogger(logger Logger)
+}

listener.go

@@ -2,9 +2,11 @@ package tacitus
 
 type ListenerService interface {
 	Open() error
-	Close()
-	Subscribe(product string)
+	Close() error
+	Subscribe(products ...string)
 	Stream() <-chan Trade
 	Error() <-chan error
+	SendErrors() bool
+	SetSendErrors(send bool)
 	SetLogger(logger Logger)
 }

trade.go

@@ -21,15 +21,22 @@ type Trade struct {
 }
 
 type TradeService interface {
-	Trade(id int) (Trade, error)
-	TradeByTradeId(id int, prod string) (Trade, error)
 	CreateTrade(t Trade) (Trade, error)
 	DeleteTrade(id int)
+
+	Trade(id int) (Trade, error)
+	TradeByTradeId(id int, prod string) (Trade, error)
 	TradesInDateRange(product string, start, end time.Time) ([]Trade, error)
 	FirstTrades(product string, limit int) ([]Trade, error)
 	LastTrades(product string, limit int) ([]Trade, error)
 	TradesAfter(product string, id, limit int) ([]Trade, error)
 	TradesBefore(product string, id, limit int) ([]Trade, error)
+
+	TradesAfterAll(product string, id int) error
+
+	Next() (Trade, error)
+	Done() bool
+	CloseRows() error
 }
 
 func ValidProduct(prod string) bool {