| // Go support for Protocol Buffers - Google's data interchange format |
| // |
| // Copyright 2015 The Go Authors. All rights reserved. |
| // https://github.com/golang/protobuf |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| // Package grpc outputs gRPC service descriptions in Go code. |
| // It runs as a plugin for the Go protocol buffer compiler plugin. |
| // It is linked in to protoc-gen-go. |
| package grpc |
| |
| import ( |
| "fmt" |
| "path" |
| "strconv" |
| "strings" |
| |
| pb "github.com/gogo/protobuf/protoc-gen-gogo/descriptor" |
| "github.com/gogo/protobuf/protoc-gen-gogo/generator" |
| ) |
| |
| // generatedCodeVersion indicates a version of the generated code. |
| // It is incremented whenever an incompatibility between the generated code and |
| // the grpc package is introduced; the generated code references |
| // a constant, grpc.SupportPackageIsVersionN (where N is generatedCodeVersion). |
| const generatedCodeVersion = 4 |
| |
| // Paths for packages used by code generated in this file, |
| // relative to the import_prefix of the generator.Generator. |
| const ( |
| contextPkgPath = "golang.org/x/net/context" |
| grpcPkgPath = "google.golang.org/grpc" |
| ) |
| |
| func init() { |
| generator.RegisterPlugin(new(grpc)) |
| } |
| |
| // grpc is an implementation of the Go protocol buffer compiler's |
| // plugin architecture. It generates bindings for gRPC support. |
| type grpc struct { |
| gen *generator.Generator |
| } |
| |
| // Name returns the name of this plugin, "grpc". |
| func (g *grpc) Name() string { |
| return "grpc" |
| } |
| |
| // The names for packages imported in the generated code. |
| // They may vary from the final path component of the import path |
| // if the name is used by other packages. |
| var ( |
| contextPkg string |
| grpcPkg string |
| ) |
| |
| // Init initializes the plugin. |
| func (g *grpc) Init(gen *generator.Generator) { |
| g.gen = gen |
| contextPkg = generator.RegisterUniquePackageName("context", nil) |
| grpcPkg = generator.RegisterUniquePackageName("grpc", nil) |
| } |
| |
| // Given a type name defined in a .proto, return its object. |
| // Also record that we're using it, to guarantee the associated import. |
| func (g *grpc) objectNamed(name string) generator.Object { |
| g.gen.RecordTypeUse(name) |
| return g.gen.ObjectNamed(name) |
| } |
| |
| // Given a type name defined in a .proto, return its name as we will print it. |
| func (g *grpc) typeName(str string) string { |
| return g.gen.TypeName(g.objectNamed(str)) |
| } |
| |
| // P forwards to g.gen.P. |
| func (g *grpc) P(args ...interface{}) { g.gen.P(args...) } |
| |
| // Generate generates code for the services in the given file. |
| func (g *grpc) Generate(file *generator.FileDescriptor) { |
| if len(file.FileDescriptorProto.Service) == 0 { |
| return |
| } |
| |
| g.P("// Reference imports to suppress errors if they are not otherwise used.") |
| g.P("var _ ", contextPkg, ".Context") |
| g.P("var _ ", grpcPkg, ".ClientConn") |
| g.P() |
| |
| // Assert version compatibility. |
| g.P("// This is a compile-time assertion to ensure that this generated file") |
| g.P("// is compatible with the grpc package it is being compiled against.") |
| g.P("const _ = ", grpcPkg, ".SupportPackageIsVersion", generatedCodeVersion) |
| g.P() |
| |
| for i, service := range file.FileDescriptorProto.Service { |
| g.generateService(file, service, i) |
| } |
| } |
| |
| // GenerateImports generates the import declaration for this file. |
| func (g *grpc) GenerateImports(file *generator.FileDescriptor) { |
| if len(file.FileDescriptorProto.Service) == 0 { |
| return |
| } |
| g.P("import ", contextPkg, " ", generator.GoImportPath(path.Join(string(g.gen.ImportPrefix), contextPkgPath))) |
| g.P("import ", grpcPkg, " ", generator.GoImportPath(path.Join(string(g.gen.ImportPrefix), grpcPkgPath))) |
| g.P() |
| } |
| |
| // reservedClientName records whether a client name is reserved on the client side. |
| var reservedClientName = map[string]bool{ |
| // TODO: do we need any in gRPC? |
| } |
| |
| func unexport(s string) string { return strings.ToLower(s[:1]) + s[1:] } |
| |
| // deprecationComment is the standard comment added to deprecated |
| // messages, fields, enums, and enum values. |
| var deprecationComment = "// Deprecated: Do not use." |
| |
| // generateService generates all the code for the named service. |
| func (g *grpc) generateService(file *generator.FileDescriptor, service *pb.ServiceDescriptorProto, index int) { |
| path := fmt.Sprintf("6,%d", index) // 6 means service. |
| |
| origServName := service.GetName() |
| fullServName := origServName |
| if pkg := file.GetPackage(); pkg != "" { |
| fullServName = pkg + "." + fullServName |
| } |
| servName := generator.CamelCase(origServName) |
| deprecated := service.GetOptions().GetDeprecated() |
| |
| g.P() |
| g.P("// Client API for ", servName, " service") |
| g.P() |
| |
| // Client interface. |
| if deprecated { |
| g.P(deprecationComment) |
| } |
| g.P("type ", servName, "Client interface {") |
| for i, method := range service.Method { |
| g.gen.PrintComments(fmt.Sprintf("%s,2,%d", path, i)) // 2 means method in a service. |
| g.P(g.generateClientSignature(servName, method)) |
| } |
| g.P("}") |
| g.P() |
| |
| // Client structure. |
| g.P("type ", unexport(servName), "Client struct {") |
| g.P("cc *", grpcPkg, ".ClientConn") |
| g.P("}") |
| g.P() |
| |
| // NewClient factory. |
| if deprecated { |
| g.P(deprecationComment) |
| } |
| g.P("func New", servName, "Client (cc *", grpcPkg, ".ClientConn) ", servName, "Client {") |
| g.P("return &", unexport(servName), "Client{cc}") |
| g.P("}") |
| g.P() |
| |
| var methodIndex, streamIndex int |
| serviceDescVar := "_" + servName + "_serviceDesc" |
| // Client method implementations. |
| for _, method := range service.Method { |
| var descExpr string |
| if !method.GetServerStreaming() && !method.GetClientStreaming() { |
| // Unary RPC method |
| descExpr = fmt.Sprintf("&%s.Methods[%d]", serviceDescVar, methodIndex) |
| methodIndex++ |
| } else { |
| // Streaming RPC method |
| descExpr = fmt.Sprintf("&%s.Streams[%d]", serviceDescVar, streamIndex) |
| streamIndex++ |
| } |
| g.generateClientMethod(servName, fullServName, serviceDescVar, method, descExpr) |
| } |
| |
| g.P("// Server API for ", servName, " service") |
| g.P() |
| |
| // Server interface. |
| if deprecated { |
| g.P(deprecationComment) |
| } |
| serverType := servName + "Server" |
| g.P("type ", serverType, " interface {") |
| for i, method := range service.Method { |
| g.gen.PrintComments(fmt.Sprintf("%s,2,%d", path, i)) // 2 means method in a service. |
| g.P(g.generateServerSignature(servName, method)) |
| } |
| g.P("}") |
| g.P() |
| |
| // Server registration. |
| if deprecated { |
| g.P(deprecationComment) |
| } |
| g.P("func Register", servName, "Server(s *", grpcPkg, ".Server, srv ", serverType, ") {") |
| g.P("s.RegisterService(&", serviceDescVar, `, srv)`) |
| g.P("}") |
| g.P() |
| |
| // Server handler implementations. |
| var handlerNames []string |
| for _, method := range service.Method { |
| hname := g.generateServerMethod(servName, fullServName, method) |
| handlerNames = append(handlerNames, hname) |
| } |
| |
| // Service descriptor. |
| g.P("var ", serviceDescVar, " = ", grpcPkg, ".ServiceDesc {") |
| g.P("ServiceName: ", strconv.Quote(fullServName), ",") |
| g.P("HandlerType: (*", serverType, ")(nil),") |
| g.P("Methods: []", grpcPkg, ".MethodDesc{") |
| for i, method := range service.Method { |
| if method.GetServerStreaming() || method.GetClientStreaming() { |
| continue |
| } |
| g.P("{") |
| g.P("MethodName: ", strconv.Quote(method.GetName()), ",") |
| g.P("Handler: ", handlerNames[i], ",") |
| g.P("},") |
| } |
| g.P("},") |
| g.P("Streams: []", grpcPkg, ".StreamDesc{") |
| for i, method := range service.Method { |
| if !method.GetServerStreaming() && !method.GetClientStreaming() { |
| continue |
| } |
| g.P("{") |
| g.P("StreamName: ", strconv.Quote(method.GetName()), ",") |
| g.P("Handler: ", handlerNames[i], ",") |
| if method.GetServerStreaming() { |
| g.P("ServerStreams: true,") |
| } |
| if method.GetClientStreaming() { |
| g.P("ClientStreams: true,") |
| } |
| g.P("},") |
| } |
| g.P("},") |
| g.P("Metadata: \"", file.GetName(), "\",") |
| g.P("}") |
| g.P() |
| } |
| |
| // generateClientSignature returns the client-side signature for a method. |
| func (g *grpc) generateClientSignature(servName string, method *pb.MethodDescriptorProto) string { |
| origMethName := method.GetName() |
| methName := generator.CamelCase(origMethName) |
| if reservedClientName[methName] { |
| methName += "_" |
| } |
| reqArg := ", in *" + g.typeName(method.GetInputType()) |
| if method.GetClientStreaming() { |
| reqArg = "" |
| } |
| respName := "*" + g.typeName(method.GetOutputType()) |
| if method.GetServerStreaming() || method.GetClientStreaming() { |
| respName = servName + "_" + generator.CamelCase(origMethName) + "Client" |
| } |
| return fmt.Sprintf("%s(ctx %s.Context%s, opts ...%s.CallOption) (%s, error)", methName, contextPkg, reqArg, grpcPkg, respName) |
| } |
| |
| func (g *grpc) generateClientMethod(servName, fullServName, serviceDescVar string, method *pb.MethodDescriptorProto, descExpr string) { |
| sname := fmt.Sprintf("/%s/%s", fullServName, method.GetName()) |
| methName := generator.CamelCase(method.GetName()) |
| inType := g.typeName(method.GetInputType()) |
| outType := g.typeName(method.GetOutputType()) |
| |
| if method.GetOptions().GetDeprecated() { |
| g.P(deprecationComment) |
| } |
| g.P("func (c *", unexport(servName), "Client) ", g.generateClientSignature(servName, method), "{") |
| if !method.GetServerStreaming() && !method.GetClientStreaming() { |
| g.P("out := new(", outType, ")") |
| // TODO: Pass descExpr to Invoke. |
| g.P(`err := c.cc.Invoke(ctx, "`, sname, `", in, out, opts...)`) |
| g.P("if err != nil { return nil, err }") |
| g.P("return out, nil") |
| g.P("}") |
| g.P() |
| return |
| } |
| streamType := unexport(servName) + methName + "Client" |
| g.P("stream, err := c.cc.NewStream(ctx, ", descExpr, `, "`, sname, `", opts...)`) |
| g.P("if err != nil { return nil, err }") |
| g.P("x := &", streamType, "{stream}") |
| if !method.GetClientStreaming() { |
| g.P("if err := x.ClientStream.SendMsg(in); err != nil { return nil, err }") |
| g.P("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }") |
| } |
| g.P("return x, nil") |
| g.P("}") |
| g.P() |
| |
| genSend := method.GetClientStreaming() |
| genRecv := method.GetServerStreaming() |
| genCloseAndRecv := !method.GetServerStreaming() |
| |
| // Stream auxiliary types and methods. |
| g.P("type ", servName, "_", methName, "Client interface {") |
| if genSend { |
| g.P("Send(*", inType, ") error") |
| } |
| if genRecv { |
| g.P("Recv() (*", outType, ", error)") |
| } |
| if genCloseAndRecv { |
| g.P("CloseAndRecv() (*", outType, ", error)") |
| } |
| g.P(grpcPkg, ".ClientStream") |
| g.P("}") |
| g.P() |
| |
| g.P("type ", streamType, " struct {") |
| g.P(grpcPkg, ".ClientStream") |
| g.P("}") |
| g.P() |
| |
| if genSend { |
| g.P("func (x *", streamType, ") Send(m *", inType, ") error {") |
| g.P("return x.ClientStream.SendMsg(m)") |
| g.P("}") |
| g.P() |
| } |
| if genRecv { |
| g.P("func (x *", streamType, ") Recv() (*", outType, ", error) {") |
| g.P("m := new(", outType, ")") |
| g.P("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }") |
| g.P("return m, nil") |
| g.P("}") |
| g.P() |
| } |
| if genCloseAndRecv { |
| g.P("func (x *", streamType, ") CloseAndRecv() (*", outType, ", error) {") |
| g.P("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }") |
| g.P("m := new(", outType, ")") |
| g.P("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }") |
| g.P("return m, nil") |
| g.P("}") |
| g.P() |
| } |
| } |
| |
| // generateServerSignature returns the server-side signature for a method. |
| func (g *grpc) generateServerSignature(servName string, method *pb.MethodDescriptorProto) string { |
| origMethName := method.GetName() |
| methName := generator.CamelCase(origMethName) |
| if reservedClientName[methName] { |
| methName += "_" |
| } |
| |
| var reqArgs []string |
| ret := "error" |
| if !method.GetServerStreaming() && !method.GetClientStreaming() { |
| reqArgs = append(reqArgs, contextPkg+".Context") |
| ret = "(*" + g.typeName(method.GetOutputType()) + ", error)" |
| } |
| if !method.GetClientStreaming() { |
| reqArgs = append(reqArgs, "*"+g.typeName(method.GetInputType())) |
| } |
| if method.GetServerStreaming() || method.GetClientStreaming() { |
| reqArgs = append(reqArgs, servName+"_"+generator.CamelCase(origMethName)+"Server") |
| } |
| |
| return methName + "(" + strings.Join(reqArgs, ", ") + ") " + ret |
| } |
| |
| func (g *grpc) generateServerMethod(servName, fullServName string, method *pb.MethodDescriptorProto) string { |
| methName := generator.CamelCase(method.GetName()) |
| hname := fmt.Sprintf("_%s_%s_Handler", servName, methName) |
| inType := g.typeName(method.GetInputType()) |
| outType := g.typeName(method.GetOutputType()) |
| |
| if !method.GetServerStreaming() && !method.GetClientStreaming() { |
| g.P("func ", hname, "(srv interface{}, ctx ", contextPkg, ".Context, dec func(interface{}) error, interceptor ", grpcPkg, ".UnaryServerInterceptor) (interface{}, error) {") |
| g.P("in := new(", inType, ")") |
| g.P("if err := dec(in); err != nil { return nil, err }") |
| g.P("if interceptor == nil { return srv.(", servName, "Server).", methName, "(ctx, in) }") |
| g.P("info := &", grpcPkg, ".UnaryServerInfo{") |
| g.P("Server: srv,") |
| g.P("FullMethod: ", strconv.Quote(fmt.Sprintf("/%s/%s", fullServName, methName)), ",") |
| g.P("}") |
| g.P("handler := func(ctx ", contextPkg, ".Context, req interface{}) (interface{}, error) {") |
| g.P("return srv.(", servName, "Server).", methName, "(ctx, req.(*", inType, "))") |
| g.P("}") |
| g.P("return interceptor(ctx, in, info, handler)") |
| g.P("}") |
| g.P() |
| return hname |
| } |
| streamType := unexport(servName) + methName + "Server" |
| g.P("func ", hname, "(srv interface{}, stream ", grpcPkg, ".ServerStream) error {") |
| if !method.GetClientStreaming() { |
| g.P("m := new(", inType, ")") |
| g.P("if err := stream.RecvMsg(m); err != nil { return err }") |
| g.P("return srv.(", servName, "Server).", methName, "(m, &", streamType, "{stream})") |
| } else { |
| g.P("return srv.(", servName, "Server).", methName, "(&", streamType, "{stream})") |
| } |
| g.P("}") |
| g.P() |
| |
| genSend := method.GetServerStreaming() |
| genSendAndClose := !method.GetServerStreaming() |
| genRecv := method.GetClientStreaming() |
| |
| // Stream auxiliary types and methods. |
| g.P("type ", servName, "_", methName, "Server interface {") |
| if genSend { |
| g.P("Send(*", outType, ") error") |
| } |
| if genSendAndClose { |
| g.P("SendAndClose(*", outType, ") error") |
| } |
| if genRecv { |
| g.P("Recv() (*", inType, ", error)") |
| } |
| g.P(grpcPkg, ".ServerStream") |
| g.P("}") |
| g.P() |
| |
| g.P("type ", streamType, " struct {") |
| g.P(grpcPkg, ".ServerStream") |
| g.P("}") |
| g.P() |
| |
| if genSend { |
| g.P("func (x *", streamType, ") Send(m *", outType, ") error {") |
| g.P("return x.ServerStream.SendMsg(m)") |
| g.P("}") |
| g.P() |
| } |
| if genSendAndClose { |
| g.P("func (x *", streamType, ") SendAndClose(m *", outType, ") error {") |
| g.P("return x.ServerStream.SendMsg(m)") |
| g.P("}") |
| g.P() |
| } |
| if genRecv { |
| g.P("func (x *", streamType, ") Recv() (*", inType, ", error) {") |
| g.P("m := new(", inType, ")") |
| g.P("if err := x.ServerStream.RecvMsg(m); err != nil { return nil, err }") |
| g.P("return m, nil") |
| g.P("}") |
| g.P() |
| } |
| |
| return hname |
| } |