text: // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // http://code.google.com/p/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.
  
  // Author: kenton@google.com (Kenton Varda)
  //  Based on original Protocol Buffers design by
  //  Sanjay Ghemawat, Jeff Dean, and others.
  
  #include <google/protobuf/compiler/cpp/cpp_service.h>
  #include <google/protobuf/compiler/cpp/cpp_helpers.h>
  #include <google/protobuf/io/printer.h>
  #include <google/protobuf/stubs/strutil.h>
  
  namespace google {
  namespace protobuf {
  namespace compiler {
  namespace cpp {
  
  ServiceGenerator::ServiceGenerator(const ServiceDescriptor* descriptor,
                                     const Options& options)
    : descriptor_(descriptor) {
    vars_["classname"] = descriptor_->name();
    vars_["full_name"] = descriptor_->full_name();
    if (options.dllexport_decl.empty()) {
      vars_["dllexport"] = "";
    } else {
      vars_["dllexport"] = options.dllexport_decl + " ";
    }
  }
  
  ServiceGenerator::~ServiceGenerator() {}
  
  void ServiceGenerator::GenerateDeclarations(io::Printer* printer) {
    // Forward-declare the stub type.
    printer->Print(vars_,
      "class $classname$_Stub;\n"
      "\n");
  
    GenerateInterface(printer);
    GenerateStubDefinition(printer);
  }
  
  void ServiceGenerator::GenerateInterface(io::Printer* printer) {
    printer->Print(vars_,
      "class $dllexport$$classname$ : public ::google::protobuf::Service {\n"
      " protected:\n"
      "  // This class should be treated as an abstract interface.\n"
      "  inline $classname$() {};\n"
      " public:\n"
      "  virtual ~$classname$();\n");
    printer->Indent();
  
    printer->Print(vars_,
      "\n"
      "typedef $classname$_Stub Stub;\n"
      "\n"
      "static const ::google::protobuf::ServiceDescriptor* descriptor();\n"
      "\n");
  
    GenerateMethodSignatures(VIRTUAL, printer);
  
    printer->Print(
      "\n"
      "// implements Service ----------------------------------------------\n"
      "\n"
      "const ::google::protobuf::ServiceDescriptor* GetDescriptor();\n"
      "void CallMethod(const ::google::protobuf::MethodDescriptor* method,\n"
      "                ::google::protobuf::RpcController* controller,\n"
      "                const ::google::protobuf::Message* request,\n"
      "                ::google::protobuf::Message* response,\n"
      "                ::google::protobuf::Closure* done);\n"
      "const ::google::protobuf::Message& GetRequestPrototype(\n"
      "  const ::google::protobuf::MethodDescriptor* method) const;\n"
      "const ::google::protobuf::Message& GetResponsePrototype(\n"
      "  const ::google::protobuf::MethodDescriptor* method) const;\n");
  
    printer->Outdent();
    printer->Print(vars_,
      "\n"
      " private:\n"
      "  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS($classname$);\n"
      "};\n"
      "\n");
  }
  
  void ServiceGenerator::GenerateStubDefinition(io::Printer* printer) {
    printer->Print(vars_,
      "class $dllexport$$classname$_Stub : public $classname$ {\n"
      " public:\n");
  
    printer->Indent();
  
    printer->Print(vars_,
      "$classname$_Stub(::google::protobuf::RpcChannel* channel);\n"
      "$classname$_Stub(::google::protobuf::RpcChannel* channel,\n"
      "                 ::google::protobuf::Service::ChannelOwnership ownership);\n"
      "~$classname$_Stub();\n"
      "\n"
      "inline ::google::protobuf::RpcChannel* channel() { return channel_; }\n"
      "\n"
      "// implements $classname$ ------------------------------------------\n"
      "\n");
  
    GenerateMethodSignatures(NON_VIRTUAL, printer);
  
    printer->Outdent();
    printer->Print(vars_,
      " private:\n"
      "  ::google::protobuf::RpcChannel* channel_;\n"
      "  bool owns_channel_;\n"
      "  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS($classname$_Stub);\n"
      "};\n"
      "\n");
  }
  
  void ServiceGenerator::GenerateMethodSignatures(
      VirtualOrNon virtual_or_non, io::Printer* printer) {
    for (int i = 0; i < descriptor_->method_count(); i++) {
      const MethodDescriptor* method = descriptor_->method(i);
      map<string, string> sub_vars;
      sub_vars["name"] = method->name();
      sub_vars["input_type"] = ClassName(method->input_type(), true);
      sub_vars["output_type"] = ClassName(method->output_type(), true);
      sub_vars["virtual"] = virtual_or_non == VIRTUAL ? "virtual " : "";
  
      printer->Print(sub_vars,
        "$virtual$void $name$(::google::protobuf::RpcController* controller,\n"
        "                     const $input_type$* request,\n"
        "                     $output_type$* response,\n"
        "                     ::google::protobuf::Closure* done);\n");
    }
  }
  
  // ===================================================================
  
  void ServiceGenerator::GenerateDescriptorInitializer(
      io::Printer* printer, int index) {
    map<string, string> vars;
    vars["classname"] = descriptor_->name();
    vars["index"] = SimpleItoa(index);
  
    printer->Print(vars,
      "$classname$_descriptor_ = file->service($index$);\n");
  }
  
  // ===================================================================
  
  void ServiceGenerator::GenerateImplementation(io::Printer* printer) {
    printer->Print(vars_,
      "$classname$::~$classname$() {}\n"
      "\n"
      "const ::google::protobuf::ServiceDescriptor* $classname$::descriptor() {\n"
      "  protobuf_AssignDescriptorsOnce();\n"
      "  return $classname$_descriptor_;\n"
      "}\n"
      "\n"
      "const ::google::protobuf::ServiceDescriptor* $classname$::GetDescriptor() {\n"
      "  protobuf_AssignDescriptorsOnce();\n"
      "  return $classname$_descriptor_;\n"
      "}\n"
      "\n");
  
    // Generate methods of the interface.
    GenerateNotImplementedMethods(printer);
    GenerateCallMethod(printer);
    GenerateGetPrototype(REQUEST, printer);
    GenerateGetPrototype(RESPONSE, printer);
  
    // Generate stub implementation.
    printer->Print(vars_,
      "$classname$_Stub::$classname$_Stub(::google::protobuf::RpcChannel* channel)\n"
      "  : channel_(channel), owns_channel_(false) {}\n"
      "$classname$_Stub::$classname$_Stub(\n"
      "    ::google::protobuf::RpcChannel* channel,\n"
      "    ::google::protobuf::Service::ChannelOwnership ownership)\n"
      "  : channel_(channel),\n"
      "    owns_channel_(ownership == ::google::protobuf::Service::STUB_OWNS_CHANNEL) {}\n"
      "$classname$_Stub::~$classname$_Stub() {\n"
      "  if (owns_channel_) delete channel_;\n"
      "}\n"
      "\n");
  
    GenerateStubMethods(printer);
  }
  
  void ServiceGenerator::GenerateNotImplementedMethods(io::Printer* printer) {
    for (int i = 0; i < descriptor_->method_count(); i++) {
      const MethodDescriptor* method = descriptor_->method(i);
      map<string, string> sub_vars;
      sub_vars["classname"] = descriptor_->name();
      sub_vars["name"] = method->name();
      sub_vars["index"] = SimpleItoa(i);
      sub_vars["input_type"] = ClassName(method->input_type(), true);
      sub_vars["output_type"] = ClassName(method->output_type(), true);
  
      printer->Print(sub_vars,
        "void $classname$::$name$(::google::protobuf::RpcController* controller,\n"
        "                         const $input_type$*,\n"
        "                         $output_type$*,\n"
        "                         ::google::protobuf::Closure* done) {\n"
        "  controller->SetFailed(\"Method $name$() not implemented.\");\n"
        "  done->Run();\n"
        "}\n"
        "\n");
    }
  }
  
  void ServiceGenerator::GenerateCallMethod(io::Printer* printer) {
    printer->Print(vars_,
      "void $classname$::CallMethod(const ::google::protobuf::MethodDescriptor* method,\n"
      "                             ::google::protobuf::RpcController* controller,\n"
      "                             const ::google::protobuf::Message* request,\n"
      "                             ::google::protobuf::Message* response,\n"
      "                             ::google::protobuf::Closure* done) {\n"
      "  GOOGLE_DCHECK_EQ(method->service(), $classname$_descriptor_);\n"
      "  switch(method->index()) {\n");
  
    for (int i = 0; i < descriptor_->method_count(); i++) {
      const MethodDescriptor* method = descriptor_->method(i);
      map<string, string> sub_vars;
      sub_vars["name"] = method->name();
      sub_vars["index"] = SimpleItoa(i);
      sub_vars["input_type"] = ClassName(method->input_type(), true);
      sub_vars["output_type"] = ClassName(method->output_type(), true);
  
      // Note:  down_cast does not work here because it only works on pointers,
      //   not references.
      printer->Print(sub_vars,
        "    case $index$:\n"
        "      $name$(controller,\n"
        "             ::google::protobuf::down_cast<const $input_type$*>(request),\n"
        "             ::google::protobuf::down_cast< $output_type$*>(response),\n"
        "             done);\n"
        "      break;\n");
    }
  
    printer->Print(vars_,
      "    default:\n"
      "      GOOGLE_LOG(FATAL) << \"Bad method index; this should never happen.\";\n"
      "      break;\n"
      "  }\n"
      "}\n"
      "\n");
  }
  
  void ServiceGenerator::GenerateGetPrototype(RequestOrResponse which,
                                              io::Printer* printer) {
    if (which == REQUEST) {
      printer->Print(vars_,
        "const ::google::protobuf::Message& $classname$::GetRequestPrototype(\n");
    } else {
      printer->Print(vars_,
        "const ::google::protobuf::Message& $classname$::GetResponsePrototype(\n");
    }
  
    printer->Print(vars_,
      "    const ::google::protobuf::MethodDescriptor* method) const {\n"
      "  GOOGLE_DCHECK_EQ(method->service(), descriptor());\n"
      "  switch(method->index()) {\n");
  
    for (int i = 0; i < descriptor_->method_count(); i++) {
      const MethodDescriptor* method = descriptor_->method(i);
      const Descriptor* type =
        (which == REQUEST) ? method->input_type() : method->output_type();
  
      map<string, string> sub_vars;
      sub_vars["index"] = SimpleItoa(i);
      sub_vars["type"] = ClassName(type, true);
  
      printer->Print(sub_vars,
        "    case $index$:\n"
        "      return $type$::default_instance();\n");
    }
  
    printer->Print(vars_,
      "    default:\n"
      "      GOOGLE_LOG(FATAL) << \"Bad method index; this should never happen.\";\n"
      "      return *reinterpret_cast< ::google::protobuf::Message*>(NULL);\n"
      "  }\n"
      "}\n"
      "\n");
  }
  
  void ServiceGenerator::GenerateStubMethods(io::Printer* printer) {
    for (int i = 0; i < descriptor_->method_count(); i++) {
      const MethodDescriptor* method = descriptor_->method(i);
      map<string, string> sub_vars;
      sub_vars["classname"] = descriptor_->name();
      sub_vars["name"] = method->name();
      sub_vars["index"] = SimpleItoa(i);
      sub_vars["input_type"] = ClassName(method->input_type(), true);
      sub_vars["output_type"] = ClassName(method->output_type(), true);
  
      printer->Print(sub_vars,
        "void $classname$_Stub::$name$(::google::protobuf::RpcController* controller,\n"
        "                              const $input_type$* request,\n"
        "                              $output_type$* response,\n"
        "                              ::google::protobuf::Closure* done) {\n"
        "  channel_->CallMethod(descriptor()->method($index$),\n"
        "                       controller, request, response, done);\n"
        "}\n");
    }
  }
  
  }  // namespace cpp
  }  // namespace compiler
  }  // namespace protobuf
  }  // namespace google
  