flush_v3 (#188)

## Pull Request template
Please, go through these steps before clicking submit on this PR.

1. Give a descriptive title to your PR.
2. Provide a description of your changes.
3. Make sure you have some relevant tests.
4. Put `closes #XXXX` in your comment to auto-close the issue that your PR fixes (if applicable).

**PLEASE REMOVE THIS TEMPLATE BEFORE SUBMITTING**

Co-authored-by: Gorbunov Kirill Andreevich <kgorbunov@mtsbank.ru>
Reviewed-on: #188
Co-authored-by: Кирилл Горбунов <kirya_gorbunov_2015@mail.ru>
Co-committed-by: Кирилл Горбунов <kirya_gorbunov_2015@mail.ru>

go.mod

@@ -5,17 +5,18 @@ go 1.18
 require (
 	go.unistack.org/micro-codec-yaml/v3 v3.10.0
 	go.unistack.org/micro-proto/v3 v3.3.1
-	go.unistack.org/micro/v3 v3.10.42
-	golang.org/x/net v0.14.0
+	go.unistack.org/micro/v3 v3.10.52
+	golang.org/x/net v0.22.0
 )
 
 require (
-	github.com/golang/protobuf v1.5.3 // indirect
-	github.com/google/gnostic v0.6.9 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20230526203410-71b5a4ffd15e // indirect
-	google.golang.org/grpc v1.57.0 // indirect
-	google.golang.org/protobuf v1.31.0 // indirect
-	gopkg.in/yaml.v2 v2.4.0 // indirect
+	github.com/golang/protobuf v1.5.4 // indirect
+	github.com/google/gnostic v0.7.0 // indirect
+	github.com/google/gnostic-models v0.6.9-0.20230804172637-c7be7c783f49 // indirect
+	golang.org/x/sys v0.18.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240314234333-6e1732d8331c // indirect
+	google.golang.org/grpc v1.62.1 // indirect
+	google.golang.org/protobuf v1.33.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
-	sigs.k8s.io/yaml v1.3.0 // indirect
+	sigs.k8s.io/yaml v1.4.0 // indirect
 )

handler/meter/meter.go

@@ -41,9 +41,10 @@ type Handler struct {
 type Option func(*Options)
 
 type Options struct {
-	Meter        meter.Meter
-	Name         string
-	MeterOptions []meter.Option
+	Meter           meter.Meter
+	Name            string
+	MeterOptions    []meter.Option
+	DisableCompress bool
 }
 
 func Meter(m meter.Meter) Option {
@@ -58,6 +59,12 @@ func Name(name string) Option {
 	}
 }
 
+func DisableCompress(g bool) Option {
+	return func(o *Options) {
+		o.DisableCompress = g
+	}
+}
+
 func MeterOptions(opts ...meter.Option) Option {
 	return func(o *Options) {
 		o.MeterOptions = append(o.MeterOptions, opts...)
@@ -65,7 +72,7 @@ func MeterOptions(opts ...meter.Option) Option {
 }
 
 func NewOptions(opts ...Option) Options {
-	options := Options{Meter: meter.DefaultMeter}
+	options := Options{Meter: meter.DefaultMeter, DisableCompress: false}
 	for _, o := range opts {
 		o(&options)
 	}
@@ -89,8 +96,9 @@ func (h *Handler) Metrics(ctx context.Context, req *codecpb.Frame, rsp *codecpb.
 
 	w := io.Writer(buf)
 
-	if md, ok := metadata.FromIncomingContext(ctx); gzipAccepted(md) && ok {
-		md.Set(contentEncodingHeader, "gzip")
+	if md, ok := metadata.FromOutgoingContext(ctx); gzipAccepted(md) && ok && !h.opts.DisableCompress {
+		omd, _ := metadata.FromOutgoingContext(ctx)
+		omd.Set(contentEncodingHeader, "gzip")
 		gz := gzipPool.Get().(*gzip.Writer)
 		defer gzipPool.Put(gz)
 
@@ -98,6 +106,7 @@ func (h *Handler) Metrics(ctx context.Context, req *codecpb.Frame, rsp *codecpb.
 		defer gz.Close()
 
 		w = gz
+		gz.Flush()
 	}
 
 	if err := h.opts.Meter.Write(w, h.opts.MeterOptions...); err != nil {

http.go

@@ -35,6 +35,7 @@ type Server struct {
 	pathHandlers *rhttp.Trie
 	opts         server.Options
 	registerRPC  bool
+	registerCORS bool
 	sync.RWMutex
 	registered bool
 	init       bool
@@ -191,6 +192,11 @@ func (h *Server) NewHandler(handler interface{}, opts ...server.HandlerOption) s
 		}
 	*/
 
+	registerCORS := false
+	if v, ok := options.Context.Value(registerCORSHandlerKey{}).(bool); ok && v {
+		registerCORS = true
+	}
+
 	for hn, md := range options.Metadata {
 		var method reflect.Method
 		mname := hn[strings.Index(hn, ".")+1:]
@@ -223,13 +229,22 @@ func (h *Server) NewHandler(handler interface{}, opts ...server.HandlerOption) s
 		pth := &patHandler{mtype: mtype, name: name, rcvr: rcvr}
 		hdlr.name = name
 
-		if err := hdlr.handlers.Insert([]string{md["Method"]}, md["Path"], pth); err != nil {
-			h.opts.Logger.Errorf(h.opts.Context, "cant add handler for %s %s", md["Method"], md["Path"])
+		methods := []string{md["Method"]}
+		if registerCORS {
+			methods = append(methods, http.MethodOptions)
+		}
+
+		if err := hdlr.handlers.Insert(methods, md["Path"], pth); err != nil {
+			h.opts.Logger.Errorf(h.opts.Context, "cant add handler for %v %s", methods, md["Path"])
 		}
 
 		if h.registerRPC {
-			h.opts.Logger.Infof(h.opts.Context, "register rpc handler for http.MethodPost %s /%s", hn, hn)
-			if err := hdlr.handlers.Insert([]string{http.MethodPost}, "/"+hn, pth); err != nil {
+			methods := []string{http.MethodPost}
+			if registerCORS {
+				methods = append(methods, http.MethodOptions)
+			}
+
+			if err := hdlr.handlers.Insert(methods, "/"+hn, pth); err != nil {
 				h.opts.Logger.Errorf(h.opts.Context, "cant add rpc handler for http.MethodPost %s /%s", hn, hn)
 			}
 		}
@@ -273,13 +288,23 @@ func (h *Server) NewHandler(handler interface{}, opts ...server.HandlerOption) s
 		pth := &patHandler{mtype: mtype, name: name, rcvr: rcvr}
 		hdlr.name = name
 
-		if err := hdlr.handlers.Insert([]string{md.Method}, md.Path, pth); err != nil {
+		methods := []string{md.Method}
+		if registerCORS {
+			methods = append(methods, http.MethodOptions)
+		}
+
+		if err := hdlr.handlers.Insert(methods, md.Path, pth); err != nil {
 			h.opts.Logger.Errorf(h.opts.Context, "cant add handler for %s %s", md.Method, md.Path)
 		}
 
 		if h.registerRPC {
+			methods := []string{http.MethodPost}
+			if registerCORS {
+				methods = append(methods, http.MethodOptions)
+			}
+
 			h.opts.Logger.Infof(h.opts.Context, "register rpc handler for http.MethodPost %s /%s", hn, hn)
-			if err := hdlr.handlers.Insert([]string{http.MethodPost}, "/"+hn, pth); err != nil {
+			if err := hdlr.handlers.Insert(methods, "/"+hn, pth); err != nil {
 				h.opts.Logger.Errorf(h.opts.Context, "cant add rpc handler for http.MethodPost %s /%s", hn, hn)
 			}
 		}
@@ -552,7 +577,6 @@ func (h *Server) Start() error {
 	fn := handler
 
 	var hs *http.Server
-	var srvFunc func(net.Listener) error
 	if h.opts.Context != nil {
 		if mwf, ok := h.opts.Context.Value(middlewareKey{}).([]func(http.Handler) http.Handler); ok && len(mwf) > 0 {
 			// wrap the handler func
@@ -563,24 +587,16 @@ func (h *Server) Start() error {
 		var ok bool
 		if hs, ok = h.opts.Context.Value(serverKey{}).(*http.Server); ok && hs != nil {
 			hs.Handler = fn
-			srvFunc = hs.Serve
+		} else {
+			hs = &http.Server{Handler: fn}
 		}
 	}
 
-	if srvFunc != nil {
-		go func() {
-			if cerr := srvFunc(ts); cerr != nil && !errors.Is(cerr, net.ErrClosed) {
-				h.opts.Logger.Error(h.opts.Context, cerr)
-			}
-		}()
-	} else {
-		go func() {
-			hs = &http.Server{Handler: fn}
-			if cerr := hs.Serve(ts); cerr != nil && !errors.Is(cerr, net.ErrClosed) {
-				h.opts.Logger.Error(h.opts.Context, cerr)
-			}
-		}()
-	}
+	go func() {
+		if cerr := hs.Serve(ts); cerr != nil && !errors.Is(cerr, net.ErrClosed) {
+			h.opts.Logger.Error(h.opts.Context, cerr)
+		}
+	}()
 
 	go func() {
 		t := new(time.Ticker)

options.go

@@ -133,6 +133,13 @@ func RegisterRPCHandler(b bool) server.Option {
 	return server.SetOption(registerRPCHandlerKey{}, b)
 }
 
+type registerCORSHandlerKey struct{}
+
+// RegisterCORSHandler registers cors endpoints with /ServiceName.ServiceEndpoint method POPTIONSOST
+func RegisterCORSHandler(b bool) server.HandlerOption {
+	return server.SetHandlerOption(registerCORSHandlerKey{}, b)
+}
+
 type handlerEndpointsKey struct{}
 
 type EndpointMetadata struct {