export registry util function to safe copy registry data

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

registry/util.go

@@ -0,0 +1,141 @@
+package registry
+
+func CopyServices(current []*Service) []*Service {
+	var services []*Service
+
+	for _, service := range current {
+		// copy service
+		s := new(Service)
+		*s = *service
+
+		// copy nodes
+		var nodes []*Node
+		for _, node := range service.Nodes {
+			n := new(Node)
+			*n = *node
+			nodes = append(nodes, n)
+		}
+		s.Nodes = nodes
+
+		// copy endpoints
+		var eps []*Endpoint
+		for _, ep := range service.Endpoints {
+			e := new(Endpoint)
+			*e = *ep
+			eps = append(eps, e)
+		}
+		s.Endpoints = eps
+
+		// append service
+		services = append(services, s)
+	}
+
+	return services
+}
+
+func addServiceNodes(old, neu []*Node) []*Node {
+	var nodes []*Node
+
+	// add all new nodes
+	for _, n := range neu {
+		node := *n
+		nodes = append(nodes, &node)
+	}
+
+	// look at old nodes
+	for _, o := range old {
+		var exists bool
+
+		// check against new nodes
+		for _, n := range nodes {
+			// ids match then skip
+			if o.Id == n.Id {
+				exists = true
+				break
+			}
+		}
+
+		// keep old node
+		if !exists {
+			node := *o
+			nodes = append(nodes, &node)
+		}
+	}
+
+	return nodes
+}
+
+func AddServices(olist []*Service, nlist []*Service) []*Service {
+	var srv []*Service
+
+	for _, n := range nlist {
+		var seen bool
+		for _, o := range olist {
+			if o.Version == n.Version {
+				sp := new(Service)
+				// make copy
+				*sp = *o
+				// set nodes
+				sp.Nodes = addServiceNodes(o.Nodes, n.Nodes)
+
+				// mark as seen
+				seen = true
+				srv = append(srv, sp)
+				break
+			} else {
+				sp := new(Service)
+				// make copy
+				*sp = *o
+				srv = append(srv, sp)
+			}
+		}
+		if !seen {
+			srv = append(srv, CopyServices([]*Service{n})...)
+		}
+	}
+	return srv
+}
+
+func delServiceNodes(old, del []*Node) []*Node {
+	var nodes []*Node
+	for _, o := range old {
+		var rem bool
+		for _, n := range del {
+			if o.Id == n.Id {
+				rem = true
+				break
+			}
+		}
+		if !rem {
+			nodes = append(nodes, o)
+		}
+	}
+	return nodes
+}
+
+func DelServices(old, del []*Service) []*Service {
+	var services []*Service
+
+	for _, o := range old {
+		srv := new(Service)
+		*srv = *o
+
+		var rem bool
+
+		for _, s := range del {
+			if srv.Version == s.Version {
+				srv.Nodes = delServiceNodes(srv.Nodes, s.Nodes)
+
+				if len(srv.Nodes) == 0 {
+					rem = true
+				}
+			}
+		}
+
+		if !rem {
+			services = append(services, srv)
+		}
+	}
+
+	return services
+}