--- /dev/null
+// 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/golang/protobuf/protoc-gen-go/descriptor"
+ "github.com/golang/protobuf/protoc-gen-go/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 (")
+ g.P(contextPkg, " ", strconv.Quote(path.Join(g.gen.ImportPrefix, contextPkgPath)))
+ g.P(grpcPkg, " ", strconv.Quote(path.Join(g.gen.ImportPrefix, grpcPkgPath)))
+ g.P(")")
+ 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:] }
+
+// 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)
+
+ g.P()
+ g.P("// Client API for ", servName, " service")
+ g.P()
+
+ // Client interface.
+ 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.
+ 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.
+ 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.
+ 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())
+
+ 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 := ", grpcPkg, `.Invoke(ctx, "`, sname, `", in, out, c.cc, 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 := ", grpcPkg, ".NewClientStream(ctx, ", descExpr, `, c.cc, "`, 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
+}
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