v3 refactor (#1868)

* Move to v3

Co-authored-by: Ben Toogood <bentoogood@gmail.com>

server/subscriber.go

@@ -1,175 +0,0 @@
-package server
-
-import (
-	"fmt"
-	"reflect"
-
-	"github.com/micro/go-micro/v2/registry"
-)
-
-const (
-	subSig = "func(context.Context, interface{}) error"
-)
-
-type handler struct {
-	method  reflect.Value
-	reqType reflect.Type
-	ctxType reflect.Type
-}
-
-type subscriber struct {
-	topic      string
-	rcvr       reflect.Value
-	typ        reflect.Type
-	subscriber interface{}
-	handlers   []*handler
-	endpoints  []*registry.Endpoint
-	opts       SubscriberOptions
-}
-
-func newSubscriber(topic string, sub interface{}, opts ...SubscriberOption) Subscriber {
-	options := SubscriberOptions{
-		AutoAck: true,
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	var endpoints []*registry.Endpoint
-	var handlers []*handler
-
-	if typ := reflect.TypeOf(sub); typ.Kind() == reflect.Func {
-		h := &handler{
-			method: reflect.ValueOf(sub),
-		}
-
-		switch typ.NumIn() {
-		case 1:
-			h.reqType = typ.In(0)
-		case 2:
-			h.ctxType = typ.In(0)
-			h.reqType = typ.In(1)
-		}
-
-		handlers = append(handlers, h)
-
-		endpoints = append(endpoints, &registry.Endpoint{
-			Name:    "Func",
-			Request: extractSubValue(typ),
-			Metadata: map[string]string{
-				"topic":      topic,
-				"subscriber": "true",
-			},
-		})
-	} else {
-		hdlr := reflect.ValueOf(sub)
-		name := reflect.Indirect(hdlr).Type().Name()
-
-		for m := 0; m < typ.NumMethod(); m++ {
-			method := typ.Method(m)
-			h := &handler{
-				method: method.Func,
-			}
-
-			switch method.Type.NumIn() {
-			case 2:
-				h.reqType = method.Type.In(1)
-			case 3:
-				h.ctxType = method.Type.In(1)
-				h.reqType = method.Type.In(2)
-			}
-
-			handlers = append(handlers, h)
-
-			endpoints = append(endpoints, &registry.Endpoint{
-				Name:    name + "." + method.Name,
-				Request: extractSubValue(method.Type),
-				Metadata: map[string]string{
-					"topic":      topic,
-					"subscriber": "true",
-				},
-			})
-		}
-	}
-
-	return &subscriber{
-		rcvr:       reflect.ValueOf(sub),
-		typ:        reflect.TypeOf(sub),
-		topic:      topic,
-		subscriber: sub,
-		handlers:   handlers,
-		endpoints:  endpoints,
-		opts:       options,
-	}
-}
-
-func validateSubscriber(sub Subscriber) error {
-	typ := reflect.TypeOf(sub.Subscriber())
-	var argType reflect.Type
-
-	if typ.Kind() == reflect.Func {
-		name := "Func"
-		switch typ.NumIn() {
-		case 2:
-			argType = typ.In(1)
-		default:
-			return fmt.Errorf("subscriber %v takes wrong number of args: %v required signature %s", name, typ.NumIn(), subSig)
-		}
-		if !isExportedOrBuiltinType(argType) {
-			return fmt.Errorf("subscriber %v argument type not exported: %v", name, argType)
-		}
-		if typ.NumOut() != 1 {
-			return fmt.Errorf("subscriber %v has wrong number of outs: %v require signature %s",
-				name, typ.NumOut(), subSig)
-		}
-		if returnType := typ.Out(0); returnType != typeOfError {
-			return fmt.Errorf("subscriber %v returns %v not error", name, returnType.String())
-		}
-	} else {
-		hdlr := reflect.ValueOf(sub.Subscriber())
-		name := reflect.Indirect(hdlr).Type().Name()
-
-		for m := 0; m < typ.NumMethod(); m++ {
-			method := typ.Method(m)
-
-			switch method.Type.NumIn() {
-			case 3:
-				argType = method.Type.In(2)
-			default:
-				return fmt.Errorf("subscriber %v.%v takes wrong number of args: %v required signature %s",
-					name, method.Name, method.Type.NumIn(), subSig)
-			}
-
-			if !isExportedOrBuiltinType(argType) {
-				return fmt.Errorf("%v argument type not exported: %v", name, argType)
-			}
-			if method.Type.NumOut() != 1 {
-				return fmt.Errorf(
-					"subscriber %v.%v has wrong number of outs: %v require signature %s",
-					name, method.Name, method.Type.NumOut(), subSig)
-			}
-			if returnType := method.Type.Out(0); returnType != typeOfError {
-				return fmt.Errorf("subscriber %v.%v returns %v not error", name, method.Name, returnType.String())
-			}
-		}
-	}
-
-	return nil
-}
-
-func (s *subscriber) Topic() string {
-	return s.topic
-}
-
-func (s *subscriber) Subscriber() interface{} {
-	return s.subscriber
-}
-
-func (s *subscriber) Endpoints() []*registry.Endpoint {
-	return s.endpoints
-}
-
-func (s *subscriber) Options() SubscriberOptions {
-	return s.opts
-}