From b85dca11f7f8f94bad023ec6e8a0a9b80ca04585 Mon Sep 17 00:00:00 2001 From: Damien Neil Date: Mon, 9 Mar 2020 15:32:07 -0700 Subject: [PATCH] cmd/protoc-gen-go-grpc: add code generator Add a code generator for gRPC services. No tests included here. A followup PR updates code generation to use this generator, which acts as a test of the generator as well. --- cmd/protoc-gen-go-grpc/gengogrpc/grpc.go | 415 +++++++++++++++++++++++ cmd/protoc-gen-go-grpc/go.mod | 8 + cmd/protoc-gen-go-grpc/go.sum | 14 + cmd/protoc-gen-go-grpc/main.go | 48 +++ 4 files changed, 485 insertions(+) create mode 100644 cmd/protoc-gen-go-grpc/gengogrpc/grpc.go create mode 100644 cmd/protoc-gen-go-grpc/go.mod create mode 100644 cmd/protoc-gen-go-grpc/go.sum create mode 100644 cmd/protoc-gen-go-grpc/main.go diff --git a/cmd/protoc-gen-go-grpc/gengogrpc/grpc.go b/cmd/protoc-gen-go-grpc/gengogrpc/grpc.go new file mode 100644 index 000000000000..2ba4f5dad679 --- /dev/null +++ b/cmd/protoc-gen-go-grpc/gengogrpc/grpc.go @@ -0,0 +1,415 @@ +/* + * + * Copyright 2020 gRPC authors. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + */ + +// Package gengogrpc contains the gRPC code generator. +// +// This package is exported to permit github.com/golang/protobuf/protoc-gen-go +// to depend on it. No other packages should depend on it. +package gengogrpc + +import ( + "fmt" + "strconv" + "strings" + + "google.golang.org/protobuf/compiler/protogen" + + "google.golang.org/protobuf/types/descriptorpb" +) + +const ( + contextPackage = protogen.GoImportPath("context") + grpcPackage = protogen.GoImportPath("google.golang.org/grpc") + codesPackage = protogen.GoImportPath("google.golang.org/grpc/codes") + statusPackage = protogen.GoImportPath("google.golang.org/grpc/status") +) + +// GenerateFile generates a _grpc.pb.go file containing gRPC service definitions. +func GenerateFile(gen *protogen.Plugin, file *protogen.File) *protogen.GeneratedFile { + if len(file.Services) == 0 { + return nil + } + filename := file.GeneratedFilenamePrefix + "_grpc.pb.go" + g := gen.NewGeneratedFile(filename, file.GoImportPath) + g.P("// Code generated by protoc-gen-go-grpc. DO NOT EDIT.") + g.P() + g.P("package ", file.GoPackageName) + g.P() + GenerateFileContent(gen, file, g) + return g +} + +// GenerateFileContent generates the gRPC service definitions, excluding the package statement. +func GenerateFileContent(gen *protogen.Plugin, file *protogen.File, g *protogen.GeneratedFile) { + if len(file.Services) == 0 { + return + } + + // TODO: Remove this. We don't need to include these references any more. + g.P("// Reference imports to suppress errors if they are not otherwise used.") + g.P("var _ ", contextPackage.Ident("Context")) + g.P("var _ ", grpcPackage.Ident("ClientConnInterface")) + g.P() + + 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 _ = ", grpcPackage.Ident("SupportPackageIsVersion6")) + g.P() + for _, service := range file.Services { + genService(gen, file, g, service) + } +} + +func genService(gen *protogen.Plugin, file *protogen.File, g *protogen.GeneratedFile, service *protogen.Service) { + clientName := service.GoName + "Client" + + g.P("// ", clientName, " is the client API for ", service.GoName, " service.") + g.P("//") + g.P("// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://pkg.go.dev/google.golang.org/grpc/?tab=doc#ClientConn.NewStream.") + + // Client interface. + if service.Desc.Options().(*descriptorpb.ServiceOptions).GetDeprecated() { + g.P("//") + g.P(deprecationComment) + } + g.Annotate(clientName, service.Location) + g.P("type ", clientName, " interface {") + for _, method := range service.Methods { + g.Annotate(clientName+"."+method.GoName, method.Location) + if method.Desc.Options().(*descriptorpb.MethodOptions).GetDeprecated() { + g.P(deprecationComment) + } + g.P(method.Comments.Leading, + clientSignature(g, method)) + } + g.P("}") + g.P() + + // Client structure. + g.P("type ", unexport(clientName), " struct {") + g.P("cc ", grpcPackage.Ident("ClientConnInterface")) + g.P("}") + g.P() + + // NewClient factory. + if service.Desc.Options().(*descriptorpb.ServiceOptions).GetDeprecated() { + g.P(deprecationComment) + } + g.P("func New", clientName, " (cc ", grpcPackage.Ident("ClientConnInterface"), ") ", clientName, " {") + g.P("return &", unexport(clientName), "{cc}") + g.P("}") + g.P() + + var methodIndex, streamIndex int + // Client method implementations. + for _, method := range service.Methods { + if !method.Desc.IsStreamingServer() && !method.Desc.IsStreamingClient() { + // Unary RPC method + genClientMethod(gen, file, g, method, methodIndex) + methodIndex++ + } else { + // Streaming RPC method + genClientMethod(gen, file, g, method, streamIndex) + streamIndex++ + } + } + + // Server interface. + serverType := service.GoName + "Server" + g.P("// ", serverType, " is the server API for ", service.GoName, " service.") + if service.Desc.Options().(*descriptorpb.ServiceOptions).GetDeprecated() { + g.P("//") + g.P(deprecationComment) + } + g.Annotate(serverType, service.Location) + g.P("type ", serverType, " interface {") + for _, method := range service.Methods { + g.Annotate(serverType+"."+method.GoName, method.Location) + if method.Desc.Options().(*descriptorpb.MethodOptions).GetDeprecated() { + g.P(deprecationComment) + } + g.P(method.Comments.Leading, + serverSignature(g, method)) + } + g.P("}") + g.P() + + // Server Unimplemented struct for forward compatibility. + g.P("// Unimplemented", serverType, " can be embedded to have forward compatible implementations.") + g.P("type Unimplemented", serverType, " struct {") + g.P("}") + g.P() + for _, method := range service.Methods { + nilArg := "" + if !method.Desc.IsStreamingClient() && !method.Desc.IsStreamingServer() { + nilArg = "nil," + } + g.P("func (*Unimplemented", serverType, ") ", serverSignature(g, method), "{") + g.P("return ", nilArg, statusPackage.Ident("Errorf"), "(", codesPackage.Ident("Unimplemented"), `, "method `, method.GoName, ` not implemented")`) + g.P("}") + } + g.P() + + // Server registration. + if service.Desc.Options().(*descriptorpb.ServiceOptions).GetDeprecated() { + g.P(deprecationComment) + } + serviceDescVar := "_" + service.GoName + "_serviceDesc" + g.P("func Register", service.GoName, "Server(s *", grpcPackage.Ident("Server"), ", srv ", serverType, ") {") + g.P("s.RegisterService(&", serviceDescVar, `, srv)`) + g.P("}") + g.P() + + // Server handler implementations. + var handlerNames []string + for _, method := range service.Methods { + hname := genServerMethod(gen, file, g, method) + handlerNames = append(handlerNames, hname) + } + + // Service descriptor. + g.P("var ", serviceDescVar, " = ", grpcPackage.Ident("ServiceDesc"), " {") + g.P("ServiceName: ", strconv.Quote(string(service.Desc.FullName())), ",") + g.P("HandlerType: (*", serverType, ")(nil),") + g.P("Methods: []", grpcPackage.Ident("MethodDesc"), "{") + for i, method := range service.Methods { + if method.Desc.IsStreamingClient() || method.Desc.IsStreamingServer() { + continue + } + g.P("{") + g.P("MethodName: ", strconv.Quote(string(method.Desc.Name())), ",") + g.P("Handler: ", handlerNames[i], ",") + g.P("},") + } + g.P("},") + g.P("Streams: []", grpcPackage.Ident("StreamDesc"), "{") + for i, method := range service.Methods { + if !method.Desc.IsStreamingClient() && !method.Desc.IsStreamingServer() { + continue + } + g.P("{") + g.P("StreamName: ", strconv.Quote(string(method.Desc.Name())), ",") + g.P("Handler: ", handlerNames[i], ",") + if method.Desc.IsStreamingServer() { + g.P("ServerStreams: true,") + } + if method.Desc.IsStreamingClient() { + g.P("ClientStreams: true,") + } + g.P("},") + } + g.P("},") + g.P("Metadata: \"", file.Desc.Path(), "\",") + g.P("}") + g.P() +} + +func clientSignature(g *protogen.GeneratedFile, method *protogen.Method) string { + s := method.GoName + "(ctx " + g.QualifiedGoIdent(contextPackage.Ident("Context")) + if !method.Desc.IsStreamingClient() { + s += ", in *" + g.QualifiedGoIdent(method.Input.GoIdent) + } + s += ", opts ..." + g.QualifiedGoIdent(grpcPackage.Ident("CallOption")) + ") (" + if !method.Desc.IsStreamingClient() && !method.Desc.IsStreamingServer() { + s += "*" + g.QualifiedGoIdent(method.Output.GoIdent) + } else { + s += method.Parent.GoName + "_" + method.GoName + "Client" + } + s += ", error)" + return s +} + +func genClientMethod(gen *protogen.Plugin, file *protogen.File, g *protogen.GeneratedFile, method *protogen.Method, index int) { + service := method.Parent + sname := fmt.Sprintf("/%s/%s", service.Desc.FullName(), method.Desc.Name()) + + if method.Desc.Options().(*descriptorpb.MethodOptions).GetDeprecated() { + g.P(deprecationComment) + } + g.P("func (c *", unexport(service.GoName), "Client) ", clientSignature(g, method), "{") + if !method.Desc.IsStreamingServer() && !method.Desc.IsStreamingClient() { + g.P("out := new(", method.Output.GoIdent, ")") + 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(service.GoName) + method.GoName + "Client" + serviceDescVar := "_" + service.GoName + "_serviceDesc" + g.P("stream, err := c.cc.NewStream(ctx, &", serviceDescVar, ".Streams[", index, `], "`, sname, `", opts...)`) + g.P("if err != nil { return nil, err }") + g.P("x := &", streamType, "{stream}") + if !method.Desc.IsStreamingClient() { + 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.Desc.IsStreamingClient() + genRecv := method.Desc.IsStreamingServer() + genCloseAndRecv := !method.Desc.IsStreamingServer() + + // Stream auxiliary types and methods. + g.P("type ", service.GoName, "_", method.GoName, "Client interface {") + if genSend { + g.P("Send(*", method.Input.GoIdent, ") error") + } + if genRecv { + g.P("Recv() (*", method.Output.GoIdent, ", error)") + } + if genCloseAndRecv { + g.P("CloseAndRecv() (*", method.Output.GoIdent, ", error)") + } + g.P(grpcPackage.Ident("ClientStream")) + g.P("}") + g.P() + + g.P("type ", streamType, " struct {") + g.P(grpcPackage.Ident("ClientStream")) + g.P("}") + g.P() + + if genSend { + g.P("func (x *", streamType, ") Send(m *", method.Input.GoIdent, ") error {") + g.P("return x.ClientStream.SendMsg(m)") + g.P("}") + g.P() + } + if genRecv { + g.P("func (x *", streamType, ") Recv() (*", method.Output.GoIdent, ", error) {") + g.P("m := new(", method.Output.GoIdent, ")") + 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() (*", method.Output.GoIdent, ", error) {") + g.P("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }") + g.P("m := new(", method.Output.GoIdent, ")") + g.P("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }") + g.P("return m, nil") + g.P("}") + g.P() + } +} + +func serverSignature(g *protogen.GeneratedFile, method *protogen.Method) string { + var reqArgs []string + ret := "error" + if !method.Desc.IsStreamingClient() && !method.Desc.IsStreamingServer() { + reqArgs = append(reqArgs, g.QualifiedGoIdent(contextPackage.Ident("Context"))) + ret = "(*" + g.QualifiedGoIdent(method.Output.GoIdent) + ", error)" + } + if !method.Desc.IsStreamingClient() { + reqArgs = append(reqArgs, "*"+g.QualifiedGoIdent(method.Input.GoIdent)) + } + if method.Desc.IsStreamingClient() || method.Desc.IsStreamingServer() { + reqArgs = append(reqArgs, method.Parent.GoName+"_"+method.GoName+"Server") + } + return method.GoName + "(" + strings.Join(reqArgs, ", ") + ") " + ret +} + +func genServerMethod(gen *protogen.Plugin, file *protogen.File, g *protogen.GeneratedFile, method *protogen.Method) string { + service := method.Parent + hname := fmt.Sprintf("_%s_%s_Handler", service.GoName, method.GoName) + + if !method.Desc.IsStreamingClient() && !method.Desc.IsStreamingServer() { + g.P("func ", hname, "(srv interface{}, ctx ", contextPackage.Ident("Context"), ", dec func(interface{}) error, interceptor ", grpcPackage.Ident("UnaryServerInterceptor"), ") (interface{}, error) {") + g.P("in := new(", method.Input.GoIdent, ")") + g.P("if err := dec(in); err != nil { return nil, err }") + g.P("if interceptor == nil { return srv.(", service.GoName, "Server).", method.GoName, "(ctx, in) }") + g.P("info := &", grpcPackage.Ident("UnaryServerInfo"), "{") + g.P("Server: srv,") + g.P("FullMethod: ", strconv.Quote(fmt.Sprintf("/%s/%s", service.Desc.FullName(), method.GoName)), ",") + g.P("}") + g.P("handler := func(ctx ", contextPackage.Ident("Context"), ", req interface{}) (interface{}, error) {") + g.P("return srv.(", service.GoName, "Server).", method.GoName, "(ctx, req.(*", method.Input.GoIdent, "))") + g.P("}") + g.P("return interceptor(ctx, in, info, handler)") + g.P("}") + g.P() + return hname + } + streamType := unexport(service.GoName) + method.GoName + "Server" + g.P("func ", hname, "(srv interface{}, stream ", grpcPackage.Ident("ServerStream"), ") error {") + if !method.Desc.IsStreamingClient() { + g.P("m := new(", method.Input.GoIdent, ")") + g.P("if err := stream.RecvMsg(m); err != nil { return err }") + g.P("return srv.(", service.GoName, "Server).", method.GoName, "(m, &", streamType, "{stream})") + } else { + g.P("return srv.(", service.GoName, "Server).", method.GoName, "(&", streamType, "{stream})") + } + g.P("}") + g.P() + + genSend := method.Desc.IsStreamingServer() + genSendAndClose := !method.Desc.IsStreamingServer() + genRecv := method.Desc.IsStreamingClient() + + // Stream auxiliary types and methods. + g.P("type ", service.GoName, "_", method.GoName, "Server interface {") + if genSend { + g.P("Send(*", method.Output.GoIdent, ") error") + } + if genSendAndClose { + g.P("SendAndClose(*", method.Output.GoIdent, ") error") + } + if genRecv { + g.P("Recv() (*", method.Input.GoIdent, ", error)") + } + g.P(grpcPackage.Ident("ServerStream")) + g.P("}") + g.P() + + g.P("type ", streamType, " struct {") + g.P(grpcPackage.Ident("ServerStream")) + g.P("}") + g.P() + + if genSend { + g.P("func (x *", streamType, ") Send(m *", method.Output.GoIdent, ") error {") + g.P("return x.ServerStream.SendMsg(m)") + g.P("}") + g.P() + } + if genSendAndClose { + g.P("func (x *", streamType, ") SendAndClose(m *", method.Output.GoIdent, ") error {") + g.P("return x.ServerStream.SendMsg(m)") + g.P("}") + g.P() + } + if genRecv { + g.P("func (x *", streamType, ") Recv() (*", method.Input.GoIdent, ", error) {") + g.P("m := new(", method.Input.GoIdent, ")") + g.P("if err := x.ServerStream.RecvMsg(m); err != nil { return nil, err }") + g.P("return m, nil") + g.P("}") + g.P() + } + + return hname +} + +const deprecationComment = "// Deprecated: Do not use." + +func unexport(s string) string { return strings.ToLower(s[:1]) + s[1:] } diff --git a/cmd/protoc-gen-go-grpc/go.mod b/cmd/protoc-gen-go-grpc/go.mod new file mode 100644 index 000000000000..644fe6b7b076 --- /dev/null +++ b/cmd/protoc-gen-go-grpc/go.mod @@ -0,0 +1,8 @@ +module google.golang.org/grpc/cmd/protoc-gen-go-grpc + +go 1.9 + +require ( + github.com/golang/protobuf v1.4.0-rc.4 + google.golang.org/protobuf v1.20.1 +) diff --git a/cmd/protoc-gen-go-grpc/go.sum b/cmd/protoc-gen-go-grpc/go.sum new file mode 100644 index 000000000000..ba32e34512a0 --- /dev/null +++ b/cmd/protoc-gen-go-grpc/go.sum @@ -0,0 +1,14 @@ +github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8= +github.com/golang/protobuf v1.4.0-rc.1.0.20200221234624-67d41d38c208/go.mod h1:xKAWHe0F5eneWXFV3EuXVDTCmh+JuBKY0li0aMyXATA= +github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrUpVNzEA03Pprs= +github.com/golang/protobuf v1.4.0-rc.4/go.mod h1:WU3c8KckQ9AFe+yFwt9sWVRKCVIyN9cPHBJSNnbL67w= +github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU= +github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU= +github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE= +golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0= +google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8= +google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0= +google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM= +google.golang.org/protobuf v1.20.1-0.20200309200217-e05f789c0967/go.mod h1:A+miEFZTKqfCUM6K7xSMQL9OKL/b6hQv+e19PK+JZNE= +google.golang.org/protobuf v1.20.1 h1:ESRXHgpUBG5D2I5mmsQIyYxB/tQIZfSZ8wLyFDf/N/U= +google.golang.org/protobuf v1.20.1/go.mod h1:KqelGeouBkcbcuB3HCk4/YH2tmNLk6YSWA5LIWeI/lY= diff --git a/cmd/protoc-gen-go-grpc/main.go b/cmd/protoc-gen-go-grpc/main.go new file mode 100644 index 000000000000..eae90b913e90 --- /dev/null +++ b/cmd/protoc-gen-go-grpc/main.go @@ -0,0 +1,48 @@ +/* + * + * Copyright 2020 gRPC authors. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + */ + +// protoc-gen-go-grpc is a plugin for the Google protocol buffer compiler to +// generate Go code. Install it by building this program and making it +// accessible within your PATH with the name: +// protoc-gen-go-grpc +// +// The 'go-grpc' suffix becomes part of the argument for the protocol compiler, +// such that it can be invoked as: +// protoc --go-grpc_out=. path/to/file.proto +// +// This generates Go service definitions for the protocol buffer defined by +// file.proto. With that input, the output will be written to: +// path/to/file_grpc.pb.go +package main + +import ( + "google.golang.org/grpc/cmd/protoc-gen-go-grpc/gengogrpc" + "google.golang.org/protobuf/compiler/protogen" +) + +func main() { + protogen.Options{}.Run(func(gen *protogen.Plugin) error { + for _, f := range gen.Files { + if !f.Generate { + continue + } + gengogrpc.GenerateFile(gen, f) + } + return nil + }) +}