package gengateway import ( "bytes" "fmt" "strings" "text/template" "github.com/golang/glog" "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/descriptor" "github.com/grpc-ecosystem/grpc-gateway/utilities" ) type param struct { *descriptor.File Imports []descriptor.GoPackage UseRequestContext bool } type binding struct { *descriptor.Binding } // HasQueryParam determines if the binding needs parameters in query string. // // It sometimes returns true even though actually the binding does not need. // But it is not serious because it just results in a small amount of extra codes generated. func (b binding) HasQueryParam() bool { if b.Body != nil && len(b.Body.FieldPath) == 0 { return false } fields := make(map[string]bool) for _, f := range b.Method.RequestType.Fields { fields[f.GetName()] = true } if b.Body != nil { delete(fields, b.Body.FieldPath.String()) } for _, p := range b.PathParams { delete(fields, p.FieldPath.String()) } return len(fields) > 0 } func (b binding) QueryParamFilter() queryParamFilter { var seqs [][]string if b.Body != nil { seqs = append(seqs, strings.Split(b.Body.FieldPath.String(), ".")) } for _, p := range b.PathParams { seqs = append(seqs, strings.Split(p.FieldPath.String(), ".")) } return queryParamFilter{utilities.NewDoubleArray(seqs)} } // queryParamFilter is a wrapper of utilities.DoubleArray which provides String() to output DoubleArray.Encoding in a stable and predictable format. type queryParamFilter struct { *utilities.DoubleArray } func (f queryParamFilter) String() string { encodings := make([]string, len(f.Encoding)) for str, enc := range f.Encoding { encodings[enc] = fmt.Sprintf("%q: %d", str, enc) } e := strings.Join(encodings, ", ") return fmt.Sprintf("&utilities.DoubleArray{Encoding: map[string]int{%s}, Base: %#v, Check: %#v}", e, f.Base, f.Check) } type trailerParams struct { Services []*descriptor.Service UseRequestContext bool } func applyTemplate(p param) (string, error) { w := bytes.NewBuffer(nil) if err := headerTemplate.Execute(w, p); err != nil { return "", err } var targetServices []*descriptor.Service for _, svc := range p.Services { var methodWithBindingsSeen bool for _, meth := range svc.Methods { glog.V(2).Infof("Processing %s.%s", svc.GetName(), meth.GetName()) methName := strings.Title(*meth.Name) meth.Name = &methName for _, b := range meth.Bindings { methodWithBindingsSeen = true if err := handlerTemplate.Execute(w, binding{Binding: b}); err != nil { return "", err } } } if methodWithBindingsSeen { targetServices = append(targetServices, svc) } } if len(targetServices) == 0 { return "", errNoTargetService } tp := trailerParams{ Services: targetServices, UseRequestContext: p.UseRequestContext, } if err := trailerTemplate.Execute(w, tp); err != nil { return "", err } return w.String(), nil } var ( headerTemplate = template.Must(template.New("header").Parse(` // Code generated by protoc-gen-grpc-gateway. DO NOT EDIT. // source: {{.GetName}} /* Package {{.GoPkg.Name}} is a reverse proxy. It translates gRPC into RESTful JSON APIs. */ package {{.GoPkg.Name}} import ( {{range $i := .Imports}}{{if $i.Standard}}{{$i | printf "%s\n"}}{{end}}{{end}} {{range $i := .Imports}}{{if not $i.Standard}}{{$i | printf "%s\n"}}{{end}}{{end}} ) var _ codes.Code var _ io.Reader var _ status.Status var _ = runtime.String var _ = utilities.NewDoubleArray `)) handlerTemplate = template.Must(template.New("handler").Parse(` {{if and .Method.GetClientStreaming .Method.GetServerStreaming}} {{template "bidi-streaming-request-func" .}} {{else if .Method.GetClientStreaming}} {{template "client-streaming-request-func" .}} {{else}} {{template "client-rpc-request-func" .}} {{end}} `)) _ = template.Must(handlerTemplate.New("request-func-signature").Parse(strings.Replace(` {{if .Method.GetServerStreaming}} func request_{{.Method.Service.GetName}}_{{.Method.GetName}}_{{.Index}}(ctx context.Context, marshaler runtime.Marshaler, client {{.Method.Service.GetName}}Client, req *http.Request, pathParams map[string]string) ({{.Method.Service.GetName}}_{{.Method.GetName}}Client, runtime.ServerMetadata, error) {{else}} func request_{{.Method.Service.GetName}}_{{.Method.GetName}}_{{.Index}}(ctx context.Context, marshaler runtime.Marshaler, client {{.Method.Service.GetName}}Client, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {{end}}`, "\n", "", -1))) _ = template.Must(handlerTemplate.New("client-streaming-request-func").Parse(` {{template "request-func-signature" .}} { var metadata runtime.ServerMetadata stream, err := client.{{.Method.GetName}}(ctx) if err != nil { grpclog.Printf("Failed to start streaming: %v", err) return nil, metadata, err } dec := marshaler.NewDecoder(req.Body) for { var protoReq {{.Method.RequestType.GoType .Method.Service.File.GoPkg.Path}} err = dec.Decode(&protoReq) if err == io.EOF { break } if err != nil { grpclog.Printf("Failed to decode request: %v", err) return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err) } if err = stream.Send(&protoReq); err != nil { grpclog.Printf("Failed to send request: %v", err) return nil, metadata, err } } if err := stream.CloseSend(); err != nil { grpclog.Printf("Failed to terminate client stream: %v", err) return nil, metadata, err } header, err := stream.Header() if err != nil { grpclog.Printf("Failed to get header from client: %v", err) return nil, metadata, err } metadata.HeaderMD = header {{if .Method.GetServerStreaming}} return stream, metadata, nil {{else}} msg, err := stream.CloseAndRecv() metadata.TrailerMD = stream.Trailer() return msg, metadata, err {{end}} } `)) _ = template.Must(handlerTemplate.New("client-rpc-request-func").Parse(` {{if .HasQueryParam}} var ( filter_{{.Method.Service.GetName}}_{{.Method.GetName}}_{{.Index}} = {{.QueryParamFilter}} ) {{end}} {{template "request-func-signature" .}} { var protoReq {{.Method.RequestType.GoType .Method.Service.File.GoPkg.Path}} var metadata runtime.ServerMetadata {{if .Body}} if err := marshaler.NewDecoder(req.Body).Decode(&{{.Body.RHS "protoReq"}}); err != nil { return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err) } {{end}} {{if .PathParams}} var ( val string ok bool err error _ = err ) {{range $param := .PathParams}} val, ok = pathParams[{{$param | printf "%q"}}] if !ok { return nil, metadata, status.Errorf(codes.InvalidArgument, "missing parameter %s", {{$param | printf "%q"}}) } {{if $param.IsNestedProto3 }} err = runtime.PopulateFieldFromPath(&protoReq, {{$param | printf "%q"}}, val) {{else}} {{$param.RHS "protoReq"}}, err = {{$param.ConvertFuncExpr}}(val) {{end}} if err != nil { return nil, metadata, status.Errorf(codes.InvalidArgument, "type mismatch, parameter: %s, error: %v", {{$param | printf "%q"}}, err) } {{end}} {{end}} {{if .HasQueryParam}} if err := runtime.PopulateQueryParameters(&protoReq, req.URL.Query(), filter_{{.Method.Service.GetName}}_{{.Method.GetName}}_{{.Index}}); err != nil { return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err) } {{end}} {{if .Method.GetServerStreaming}} stream, err := client.{{.Method.GetName}}(ctx, &protoReq) if err != nil { return nil, metadata, err } header, err := stream.Header() if err != nil { return nil, metadata, err } metadata.HeaderMD = header return stream, metadata, nil {{else}} msg, err := client.{{.Method.GetName}}(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD)) return msg, metadata, err {{end}} }`)) _ = template.Must(handlerTemplate.New("bidi-streaming-request-func").Parse(` {{template "request-func-signature" .}} { var metadata runtime.ServerMetadata stream, err := client.{{.Method.GetName}}(ctx) if err != nil { grpclog.Printf("Failed to start streaming: %v", err) return nil, metadata, err } dec := marshaler.NewDecoder(req.Body) handleSend := func() error { var protoReq {{.Method.RequestType.GoType .Method.Service.File.GoPkg.Path}} err = dec.Decode(&protoReq) if err == io.EOF { return err } if err != nil { grpclog.Printf("Failed to decode request: %v", err) return err } if err = stream.Send(&protoReq); err != nil { grpclog.Printf("Failed to send request: %v", err) return err } return nil } if err := handleSend(); err != nil { if cerr := stream.CloseSend(); cerr != nil { grpclog.Printf("Failed to terminate client stream: %v", cerr) } if err == io.EOF { return stream, metadata, nil } return nil, metadata, err } go func() { for { if err := handleSend(); err != nil { break } } if err := stream.CloseSend(); err != nil { grpclog.Printf("Failed to terminate client stream: %v", err) } }() header, err := stream.Header() if err != nil { grpclog.Printf("Failed to get header from client: %v", err) return nil, metadata, err } metadata.HeaderMD = header return stream, metadata, nil } `)) trailerTemplate = template.Must(template.New("trailer").Parse(` {{$UseRequestContext := .UseRequestContext}} {{range $svc := .Services}} // Register{{$svc.GetName}}HandlerFromEndpoint is same as Register{{$svc.GetName}}Handler but // automatically dials to "endpoint" and closes the connection when "ctx" gets done. func Register{{$svc.GetName}}HandlerFromEndpoint(ctx context.Context, mux *runtime.ServeMux, endpoint string, opts []grpc.DialOption) (err error) { conn, err := grpc.Dial(endpoint, opts...) if err != nil { return err } defer func() { if err != nil { if cerr := conn.Close(); cerr != nil { grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr) } return } go func() { <-ctx.Done() if cerr := conn.Close(); cerr != nil { grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr) } }() }() return Register{{$svc.GetName}}Handler(ctx, mux, conn) } // Register{{$svc.GetName}}Handler registers the http handlers for service {{$svc.GetName}} to "mux". // The handlers forward requests to the grpc endpoint over "conn". func Register{{$svc.GetName}}Handler(ctx context.Context, mux *runtime.ServeMux, conn *grpc.ClientConn) error { client := New{{$svc.GetName}}Client(conn) {{range $m := $svc.Methods}} {{range $b := $m.Bindings}} mux.Handle({{$b.HTTPMethod | printf "%q"}}, pattern_{{$svc.GetName}}_{{$m.GetName}}_{{$b.Index}}, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) { {{- if $UseRequestContext }} ctx, cancel := context.WithCancel(req.Context()) {{- else -}} ctx, cancel := context.WithCancel(ctx) {{- end }} defer cancel() if cn, ok := w.(http.CloseNotifier); ok { go func(done <-chan struct{}, closed <-chan bool) { select { case <-done: case <-closed: cancel() } }(ctx.Done(), cn.CloseNotify()) } inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req) rctx, err := runtime.AnnotateContext(ctx, mux, req) if err != nil { runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err) return } resp, md, err := request_{{$svc.GetName}}_{{$m.GetName}}_{{$b.Index}}(rctx, inboundMarshaler, client, req, pathParams) ctx = runtime.NewServerMetadataContext(ctx, md) if err != nil { runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err) return } {{if $m.GetServerStreaming}} forward_{{$svc.GetName}}_{{$m.GetName}}_{{$b.Index}}(ctx, mux, outboundMarshaler, w, req, func() (proto.Message, error) { return resp.Recv() }, mux.GetForwardResponseOptions()...) {{else}} forward_{{$svc.GetName}}_{{$m.GetName}}_{{$b.Index}}(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...) {{end}} }) {{end}} {{end}} return nil } var ( {{range $m := $svc.Methods}} {{range $b := $m.Bindings}} pattern_{{$svc.GetName}}_{{$m.GetName}}_{{$b.Index}} = runtime.MustPattern(runtime.NewPattern({{$b.PathTmpl.Version}}, {{$b.PathTmpl.OpCodes | printf "%#v"}}, {{$b.PathTmpl.Pool | printf "%#v"}}, {{$b.PathTmpl.Verb | printf "%q"}})) {{end}} {{end}} ) var ( {{range $m := $svc.Methods}} {{range $b := $m.Bindings}} forward_{{$svc.GetName}}_{{$m.GetName}}_{{$b.Index}} = {{if $m.GetServerStreaming}}runtime.ForwardResponseStream{{else}}runtime.ForwardResponseMessage{{end}} {{end}} {{end}} ) {{end}}`)) )