lua_service.cpp

#include "lua_service.h"
#include "lua_helpers.h"
#include <google/protobuf/io/printer.h>
#include <google/protobuf/stubs/strutil.h>


namespace google {
namespace protobuf {
namespace compiler {
namespace mwpb_lua {


	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");
		}
	}

}}}}