package selector import ( "math/rand" "sync" "time" "github.com/micro/go-micro/registry" ) func init() { rand.Seed(time.Now().UnixNano()) } // Random is a random strategy algorithm for node selection func Random(services []*registry.Service) Next { var nodes []*registry.Node for _, service := range services { nodes = append(nodes, service.Nodes...) } return func() (*registry.Node, error) { if len(nodes) == 0 { return nil, ErrNoneAvailable } i := rand.Int() % len(nodes) return nodes[i], nil } } // RoundRobin is a roundrobin strategy algorithm for node selection func RoundRobin(services []*registry.Service) Next { var nodes []*registry.Node for _, service := range services { nodes = append(nodes, service.Nodes...) } var i int var mtx sync.Mutex return func() (*registry.Node, error) { if len(nodes) == 0 { return nil, ErrNoneAvailable } mtx.Lock() node := nodes[i%len(nodes)] i++ mtx.Unlock() return node, nil } }