src/compiler/cpp_plugin.cc

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// Generates cpp gRPC service interface out of Protobuf IDL.
//

#include <memory>
#include <string>

#include "src/compiler/cpp_generator.h"
#include "src/compiler/cpp_generator_helpers.h"
#include <google/protobuf/descriptor.h>
#include <google/protobuf/descriptor.pb.h>
#include <google/protobuf/compiler/code_generator.h>
#include <google/protobuf/compiler/plugin.h>
#include <google/protobuf/io/coded_stream.h>
#include <google/protobuf/io/zero_copy_stream.h>

class CppGrpcGenerator : public google::protobuf::compiler::CodeGenerator {
 public:
  CppGrpcGenerator() {}
  virtual ~CppGrpcGenerator() {}

  virtual bool Generate(const google::protobuf::FileDescriptor *file,
                        const std::string &parameter,
                        google::protobuf::compiler::GeneratorContext *context,
                        std::string *error) const {
    if (file->options().cc_generic_services()) {
      *error =
          "cpp grpc proto compiler plugin does not work with generic "
          "services. To generate cpp grpc APIs, please set \""
          "cc_generic_service = false\".";
      return false;
    }

    std::string file_name = grpc_cpp_generator::StripProto(file->name());

    // Generate .pb.h
    Insert(context, file_name + ".pb.h", "includes",
           grpc_cpp_generator::GetHeaderIncludes(file));
    Insert(context, file_name + ".pb.h", "namespace_scope",
           grpc_cpp_generator::GetHeaderServices(file));
    // Generate .pb.cc
    Insert(context, file_name + ".pb.cc", "includes",
           grpc_cpp_generator::GetSourceIncludes());
    Insert(context, file_name + ".pb.cc", "namespace_scope",
           grpc_cpp_generator::GetSourceServices(file));

    return true;
  }

 private:
  // Insert the given code into the given file at the given insertion point.
  void Insert(google::protobuf::compiler::GeneratorContext *context,
              const std::string &filename, const std::string &insertion_point,
              const std::string &code) const {
    std::unique_ptr<google::protobuf::io::ZeroCopyOutputStream> output(
        context->OpenForInsert(filename, insertion_point));
    google::protobuf::io::CodedOutputStream coded_out(output.get());
    coded_out.WriteRaw(code.data(), code.size());
  }
};

int main(int argc, char *argv[]) {
  CppGrpcGenerator generator;
  return google::protobuf::compiler::PluginMain(argc, argv, &generator);
}