stream: finish basic streams exchange logics

pkg/apis/error.go

@@ -0,0 +1,20 @@
+package apis
+
+import (
+	"errors"
+
+	"gorm.io/gorm"
+)
+
+var (
+	ErrEdgeNotOnline    = errors.New("edge not online")
+	ErrServiceNotOnline = errors.New("service not online")
+	ErrRPCNotOnline     = errors.New("rpc not online")
+	ErrTopicNotOnline   = errors.New("topic not online")
+	ErrIllegalEdgeID    = errors.New("illegal edgeID")
+	ErrRecordNotFound   = gorm.ErrRecordNotFound
+)
+
+var (
+	ErrStrUseOfClosedConnection = "use of closed network connection"
+)