package http import ( "bytes" "context" "fmt" "reflect" "strings" "go.unistack.org/micro/v4/broker" "go.unistack.org/micro/v4/codec" "go.unistack.org/micro/v4/metadata" "go.unistack.org/micro/v4/register" "go.unistack.org/micro/v4/server" ) var typeOfError = reflect.TypeOf((*error)(nil)).Elem() type handler struct { reqType reflect.Type ctxType reflect.Type method reflect.Value } type httpSubscriber struct { topic string rcvr reflect.Value typ reflect.Type subscriber interface{} handlers []*handler endpoints []*register.Endpoint opts server.SubscriberOptions } func newSubscriber(topic string, sub interface{}, opts ...server.SubscriberOption) server.Subscriber { options := server.NewSubscriberOptions(opts...) var endpoints []*register.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) ep := ®ister.Endpoint{ Name: "Func", Request: register.ExtractSubValue(typ), Metadata: metadata.New(2), } ep.Metadata.Set("topic", topic) ep.Metadata.Set("subscriber", "true") endpoints = append(endpoints, ep) } 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) ep := ®ister.Endpoint{ Name: name + "." + method.Name, Request: register.ExtractSubValue(method.Type), Metadata: metadata.New(2), } ep.Metadata.Set("topic", topic) ep.Metadata.Set("subscriber", "true") endpoints = append(endpoints, ep) } } return &httpSubscriber{ rcvr: reflect.ValueOf(sub), typ: reflect.TypeOf(sub), topic: topic, subscriber: sub, handlers: handlers, endpoints: endpoints, opts: options, } } func (s *httpServer) createSubHandler(sb *httpSubscriber, opts server.Options) broker.Handler { return func(p broker.Event) error { msg := p.Message() ct := msg.Header["Content-Type"] cf, err := s.newCodec(ct) if err != nil { return err } hdr := metadata.Copy(msg.Header) delete(hdr, "Content-Type") ctx := metadata.NewIncomingContext(context.Background(), hdr) results := make(chan error, len(sb.handlers)) for i := 0; i < len(sb.handlers); i++ { handler := sb.handlers[i] var isVal bool var req reflect.Value if handler.reqType.Kind() == reflect.Ptr { req = reflect.New(handler.reqType.Elem()) } else { req = reflect.New(handler.reqType) isVal = true } if isVal { req = req.Elem() } buf := bytes.NewBuffer(msg.Body) if err := cf.ReadHeader(buf, &codec.Message{}, codec.Event); err != nil { return err } if err := cf.ReadBody(buf, req.Interface()); err != nil { return err } fn := func(ctx context.Context, msg server.Message) error { var vals []reflect.Value if sb.typ.Kind() != reflect.Func { vals = append(vals, sb.rcvr) } if handler.ctxType != nil { vals = append(vals, reflect.ValueOf(ctx)) } vals = append(vals, reflect.ValueOf(msg.Body())) returnValues := handler.method.Call(vals) if err := returnValues[0].Interface(); err != nil { return err.(error) } return nil } for i := len(opts.SubWrappers); i > 0; i-- { fn = opts.SubWrappers[i-1](fn) } go func() { results <- fn(ctx, &httpMessage{ topic: sb.topic, contentType: ct, payload: req.Interface(), header: msg.Header, codec: cf, }) }() } var errors []string for i := 0; i < len(sb.handlers); i++ { if err := <-results; err != nil { errors = append(errors, err.Error()) } } if len(errors) > 0 { return fmt.Errorf("subscriber error: %s", strings.Join(errors, "\n")) } return nil } } func (s *httpSubscriber) Topic() string { return s.topic } func (s *httpSubscriber) Subscriber() interface{} { return s.subscriber } func (s *httpSubscriber) Endpoints() []*register.Endpoint { return s.endpoints } func (s *httpSubscriber) Options() server.SubscriberOptions { return s.opts }